激光照射对C57黑鼠膝骨关节炎软骨及热休克蛋白70的影响(英文)

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热休克蛋白70在肿瘤射频消融治疗中的作用

热休克蛋白70在肿瘤射频消融治疗中的作用何泽玲;曹建彪【摘要】热休克蛋白(heat shock protein, HSP)70是一类广泛存在于原核细胞和真核细胞中高度保守的蛋白质,具有一定的分子伴侣作用和疾病特异性.近年来,HSP70在肿瘤微创治疗领域的作用引起了学者们的高度关注.研究发现,HSP70在射频消融术(radiofrequency ablation, RFA)治疗肿瘤前后的表达存在差异.它对于肿瘤的诊断、治疗和转归等发挥着极其重要的作用,但目前对相关机制、调节及影响因素等方面研究较少.本文对HSP70相关基础研究及其在肿瘤RFA治疗前后变化的作用进行综述,以期为临床肿瘤RFA的应用提供更多的帮助.%Heat shock protein(HSP)70, a highly conserved protein, exists in almost all prokaryotic cells and eukaryotic cells, and has a certain molecular partner function and disease specificity. Its impact on the minimally invasive treatment of tumor has attracted high attention in recent years. The study shows that the expression of HSP70 before and after radiofrequency ablation (RFA) in tumor treatment is different. HSP70 plays an extremely important role in disease diagnosis, treatment and prognosis. But the research on mechanism, regulation and influence factors is still inadequate. In order to provide more helps to the application of RFA. This article summarizes the related basic research on HSP70 and its changes before and after RFA tumor treatment.【期刊名称】《传染病信息》【年(卷),期】2018(031)002【总页数】5页(P180-184)【关键词】肿瘤;热休克蛋白70;射频消融术【作者】何泽玲;曹建彪【作者单位】100043,首都医科大学石景山教学医院急诊科;100700 北京,陆军总医院全军肝病中心【正文语种】中文【中图分类】R735.7热休克蛋白（heat shock protein,HSP）是一类广泛存在于原核细胞和真核细胞中高度保守的蛋白质。

英语阅读

1.Bringing Nanotechnology to Health Care for the poor（纳米保健技术走向贫困国家）Nanotechnology uses matter at the level of molecules and atoms. ……better understand these risk.1.Which of the following uses of nanotechnology is NOT mentioned in the passage? To produce better and lighter building materials.2.How can quantum dots be used to confirm diseases?By lighting up in the presence of a targeted molecule.3.How can nanotechnology be used to make a drug more effective?By making a drug target the focus of a disesse.4.The follow developing countries are doing very well scientific research on nanotechnology EXEPTIran5.Which of following is the possible rish in using nano-materials mentioned in the passage?They may behave differently in he body and the environment2.Medical Journals（医学杂志）Medical journals are publications that report medical information to physicians and other health professionals..... about articles/published in that journal.1. The main readers of medical journals are (health professionals)2. Which of the following statements is NOT true?Most medical journals/publish only online.3. How many major types of articles are mentioned in the passage? Five.4. An article dealing with results from different studies on the same topic is called. ( a review article.)5.Letters to the editor enable readers of a medical journal to express comments on articles/published in that journal3 Cooking Oil Fumes Cause Tumor（厨房油烟可致癌）The leading cause of lung cancer among women in the city was cooking oil fumes while men...... experts said．1.What a new tendency in lung cancer is concluded by the researchers?D Patients with lung cancer become younger, especially females．2．Which of the following diseases is the most common among the local residents in Shanghai? B Breast cancer．3．What symptoms may be' complained of by most women with lung cancer after long term, close contact with cooking oil fumes?A Irritated eyes and throat．4．What was the local women's reaction when they learned that cooking oil fumes could lead to cancer?B Surprised5．Which of the following has relatively little connection with women's lung cancer？ D. Personal health and physical condition．4.Multivitamins Urged for All Pregnant Women（孕期妇女宜多补充多维制剂）A recent study in Tanzania found that when pregnant women took vitamins every day,.... women in developing countries.1. How many babies are born with low birth weight in the developed countries every year according to WHO?( C 2,000,000.)2. A pill of multivitamins may contain all of the following substances EXCEPTD antiviral substances.3. Which of the following is NOT one of the effects of multivitamins mentioned in the passage?A To reduce the rate of babies born too early.4. What a role do lymphocytes play in the human body?B To raise the body’s immunity against infection.5. How many percent of babies were born with low birth weight to women who were not infected with the AIDS virus and took the multivitamins according to a new study?A Less than8%.5.U.S. Eats Too Much Salt（美国人吃盐过量）People in the United States consume more than twice the recommended amount……the CDC said.1. Too much salt raises one’ s risk forD all of the above.2. How much salt do most American adults eat per day?B Closer to 3,500 mg.3. To improve their blood pressure, people should have a dietB rich in potassium and calcium.4. The high-risk groups include thoseD both A and B.5. Packaged, processed and restaurant foods are known to beC rich in salt.6.Pushbike Peril（自行车的危险）Low speed bicycle crashes can badly.... later this year．1 According to the passage，some engineers are trying to improve the handlebars becauseB.they may kill children2 In paragraph 2, the author mentions a study of serious abdominal injuriesD.to tell us why Kristy Arbogast began the project．3 Paragraph 3 mainly discusses D)how serious injuries occur4 The passage implies thatA.it is not easy to persuade manufacturers to adopt the new design.5 The new handgrip works in which of the following ways?B.It reduces the dangerous forces in bicycle accidents te-night Drinking（深夜喝咖啡）Coffee lovers beware..... to decaf after lunch.1.The author mentions “pick-me-up” to indicate thatC. coffee is a stimulant.2.Which of the following tells us how caffeine affects sleep?C. Caffeine halves the body’s levels of sleep hormone.3. What does paragraph 3 mainly discuss?A. Different effects of caffeinated coffee and decaf on sleep4.What does the experiment mentioned in paragraph 4 prove?D. Caffeine drinkers produce less sleep hormone.5. The author of this passage probably agrees thatB. we should not drink coffee after supper.8.Eat Healthy（健康饮食）“Clean your plate!” and “Be a member o f the clean-plate ……next year’s Christmas presents.1. Parents in the United States tend to ask their childrenC. not to waste food.2.Why do American restaurants serve large portions?A. Because Americans associate quantity with value.3.What happened in the l970s?D. The American waistline started to expand.4.What does the survey indicate?A. Many poor Americans want large portions.5.Which of the following is Not true of working class Americans?C. They don't want to be healthy eaters.9.U.S. to Start $3.2 Billion Child Health Study in January（美国将在一月启动一项耗资32亿美元的儿童健康研究项目）A study that will cost $3.2 billion and last more....the NIH said1.The aim of the study is to find new ways to_______C prevent or treat illness.2. Researchers will collect all the following EXCEPT______D samples of air and water from hospitals.3. It is expected that through the study the nation s health care costs______.A will be lowered in the long run.4. The babies of the participants will be followed______.B for more than two decades.5. Which is NOT true of the people in the study?D They ll be from all age groups.10.Cigars instead?（换抽雪茄）cigars a day………secondhand smoke.”1. According to the report, smoking three or four cigars a dayD. greatly increases the risk of more than one cancer for smokers.2. In the passage how many cancers are mentioned in relation to smoking cigarsdaily?B. Seven.3. What is the main idea of the article “Cigars: Health Effects and Trends” ?A. When it comes to cancer, cigars are not any safer than cigarettes.4. What is the doctors' advice to those cigar-smokers?A. To give it up completely5. In the context of this passage, “secondhand smoke” may meanD. being near cigar smokers when they are smoking.11.Sleeplessness（失眠）Insomnia or sleeplessness is a common……in the evening, etc.1. The word “insomnia” meansA. having trouble falling asleep.2. How many possible causes of sleeplessness are mentioned in the second paragraph?B. Six.3. The expression_r “Second on the list” in the second paragraph meansB. the second most important cause of sleeplessness.4. Concerning the use of sleeping pills, which of the following statements is true?D. Sleeping pills should be used in a very small amount.5. Which of the following does not fit with sleep hygiene?A. Make a rule to go to bed at a specific time every day.mon-cold Sense（关于感冒的常识）You can't beat it, but you don't have to join it.... have real benefits.1. According to the essay, you may have a cold becauseB. the spread of rhinoviruses gets people infected.2. The best way to keep yourself from getting colds isA. to keep yourself clean.3. Children have more colds becauseB. they are not immune to many cold viruses.4. When you are having a cold,C. it is certainly not the same kind of cold that you had last time.5. When one is having a cold, he often has some symptoms EXCEPTD. having a stomachache.13.Drug Reactions—A Major Cause of Death（药物反应）A dverse drug reactions may cause the deaths of over 100………. of these types of errors.1. Researchers at the University of Toronto believe thatC. ADRs have caused many deaths in America over the past 30 years.2. The investigators say thatC. 6. 7% of all hospitalized patients in American experience ADRs each year on average.3. An American research estimates that the total sum of money spent in treating ADRs each year is as much asB. $ 4, 000, 000, 000.4. The Canadian investigators think thatC. the ADR incidence figures from their research are perhaps too low.5. According to Dr. David Bates, hospitals in AmericaA. are not paying enough attention to possibilities of ADR happenings.14.DreamsStudies show that in dreams things are seen………a person's mental functioning.1. There are in general two opinions about what we experience in a dream:C. one, dreams put new information into our memories, and two, dreams have real meanings in pictures different from our logical thinking.2. According to this article, weD. almost always see different “pictures” when we are dreaming.3. In your dreams, youC. seldom feel fear now and joy later.4. This essay tells us thatB. people usually dream in an REM sleep.5. Based on what is discussed in this writing, an adult may have at most about_______ of the time of his or her sleep dreaming.C. 25%15.Warm People likely to keep Cold at Bay（乐观情绪助你远离感冒）Staying positive through..... to develop a cold.1. According to a study author, when people with a positive emotional style do get a cold, they may thinkB that their illness is not so serious2. People with a positive emotional style may have all of the following characteristics EXCEPTB selfish3. Which of the following is NOT one of the characteristics that people with a negativeemotional style may have?C Warm-blooded.4. How did the researchers test their volunteers?A By giving everyone nasal drops containing either a cold virus or a particular flu virus.5. Which of the following items is NOT included in the data that the researchers collected?D Blood test.16.Eat to Live【为生存而食】A meager diet may give you health and long life……. of calorie restriction.1. According to the passage, which of the following is NOT true?D We have to begin dieting since childhood.2. Why does the author mention an elderly mouse in paragraph 2?B To illustrate the effect of meager food on mice.3. What can be inferred about completely normally fed mice mentioned in the passage?D They are more likely to suffer from inflammation.4. According to the author, which of the following most interested the researchers？A The mice that started dieting in old age.5. According to the last two paragraphs, Spindler believes thatC dieting is not a good method to give us health and long life.17.Eating Potatoes Gives Your Immune System a Boost（食用土豆有益我们的免疫系统）Eating potatoes is not only good for bowel health…………of the SCI.1. What form of potato is the most nutrient to the human body?C Potato salad.2. What does the reduction in leucocyte levels in the body mean?A It may mean the reduced levels of inflammation.3. For what a purpose did the researchers use raw potato starch in their experiment?B They wanted to simulate the effects of a diet high in resistant starch.4. All of the following foods are rich in resistant starch EXCEPTD vegetables5. What a kind of starch is resistant starch after all?D It cannot be digested in the small intestine and ferments in the large intestine.19.Prolonging Human Life（延长人类寿命）Prolonging human life has increased........ underskilled personnel.1. The writer believes that the population explosion results fromC. a decrease in death rates.2. It can be inferred from the passage that in hunting and gathering culturesB. infants could be left dead in times of starvation.3. According to the passage, which of the following statements about retired peoplein the United States is true?A. Many of them have a very hard life.4. In Paragraph 3, the p hrase “this need” refers toD. the need to take care of a hick and weak people.5. Which of the following best describes the writer’s attitude toward most of the nursing homes, and convalescent hospitals?D. Critical.20.FDA: Human, Animal Waste Threatens Produce（人类排泄物危及农产品）The biggest food safety risk for fresh…………of imported produce.1. “Food-borne diseases” in this essay means those diseasesA. which people get by eating fruits which have been polluted2. Some fruit grower groups believe that most food-borne diseases are caused byD. people involved in distributing fresh produce.3. An FDA official said that putting the guidelines into practiceC. would not be very expensive.4. Consumer groups criticized the FDA guidelines because they didn't think that these guidelinesC. would surely be carried out.5. The last paragraph suggests thatB. a good way should be found to encourage foreign growers to follow the FDA guidelines.21.Early or Later Day Care（送儿童上日托早些还是晚些）The British psychoanalyst John Bowlby ……reasonable for infants.1. Which of the following statements would Bowlby support?C) The first three years of one's life is extremely important to the later development of personality.2. Which of the following is derivable from Bowlby's work?A) mothers should not send their children to day care centers until they are three years or older.3. It is suggested that modern societies differ from traditional societies in thatA) the parents-child relationship is more exclusive in modern societies.4. Which of the following statements is NOT an argument against Bowlby's theory?D) Parents find the immediate effects of early day care difficult to deal with.5. Which of the following best expresses the writer's attitude towards early daycare?C) The issue is controversial and its settlement calls for the use of statistics.22.Egypt felled by famine（被饥荒颠覆的埃及）Even ancient Egypts mighty pyramid builders were …….. increased dramatically.1. Why does the author mention pyramid builders?D. because even they were unable to rescue their civilization2. Which of the following factors was ultimately responsible for the fall of the civilization of ancient Egypt?A. Change of climate3. Which of the following statements is true?D. The White Nile and the Blue Nile are branches of the River Nile4. According to Krom, Egypts Old Kingdom fellA. immediately after a period of drought5. The word devastating in the last paragraph could be best replaced byB. damaging23.After-birth Depression Blamed for Woman’s Suicide（产后抑郁症-妇女自杀的罪魁祸首）A new mother apparently suffering from...... three of the own.1. Which of the following is NOT a symptom of postpartum psychosis?C. Inflamed breast.2. It was considered fortunate by Stokes’ mother in the miserable eventD. that Stokes had not taken her daughter with her.3. A patient suffering from “baby blues” may present briefly one or more of the following symptoms EXCEPTA. having an intention of suicide.4. How many bearing women have experiences of after-birth depression?B. About one fifth of them.5. Who induced the most serious consequence among the postpartum depression patients mentioned in the passage?D. Judy Kirby of Indianapolis.24.Sleep Lets Brain File Memories（睡眠促使记忆归档存储）To sleep, perchance to file? Findings published online ....... reason to go to the gym.1. Which of the following statements is neares t in meaning to the sentence “To sleep, perchance to file”?A. Does brain arrange memories in useful order during sleep?2. What is the result of the experiment with rats and mice carried out at Rutgers University?C. Somatosensory neocortex and hippocampus work together in memory consolidation.3. What is the relation of memory to glucose tolerance, as is indicated by a research mentioned in paragraph 4D. The poorer the memory, the poorer glucose tolerance.4. In what way is memory related to hippocampus shrinkage?B. The more hippocampus shrinks, the poorer one’s memory.5. According to the last paragraph, what is the ultimate reason for going to the gym?D. To control glucose levels.25.Medicine Award Kicks off Nobel Prize Announcements（诺贝尔奖的公布从医学奖开始）Two scientists who have won praise for ...... uncontrolled growth.1. Who is NOT a likely candidate for this year's Nobel Prize in medicine?C Linda Buck.2. Which is NOT true of Alfred Nobel?D He gave clear instructions on how to select winners.3. Which was NOT originally one of the Nobel Prizes?D The economics prize.4. The word "kicks" in line 6 from the bottom probably means ________.A excitement.5. The research by Blackburn and Greider helps suggest the role of ________.D telomerase in the growth of cancer cells.26.Obesity: the Scourge of the Western World(肥胖症-西方世界的灾祸)Obesity is rapidly becoming a new scourge ..... population group.1. it is estimated that there are _____ people suffering from obesity in the world.A. 250,000,0002. It seems that the _____ people are least affected by obesity among the developed countries 和 areas mentioned in the passage.D. Japanese3. Which of the following is most often accompanied by obesity?C. Diabetes.4. What is the correlation between body weight 和 heart disease 和 blood pressure?C. The more body weight one gains, the more risk of heart disease 和 high blood pressure he has.5. From the last paragraph we may infer that one of the effective measures suggested by Ludnik to prevent children from being obese would beB. to tell them to spend less time watching TV.27.New Attempts to Eradicate AIDS Virus（根除艾滋病的新突破）A high-profile attempt to eradicate the AIDS ...... or more, he says.1. According to the passage, the attempt to eradicate the AIDS virusA. continues to be hopeful.2. Which is NOT true about the study?D. 16 patients did not go through the whole study.3. What do He's words “Bear in mind undetectable does not equal absent ”mean?A. AIDS virus can be undetectable in the blood.4. How do we prove that the drugs have wiped out the remaining viruses?D. To stop the drugs to see if the virus comes back.5. Other scientists are looking at experiments that are similar in that they areD. bold28.Diseases of Agricultural Plants（农作物的病害）Plants, like animals, are subject to diseases………primary virus infection.1. How many diseases are known to attack wheat?D. Around 40.2. According to this passage, which of the following would a plant disease result in if it was left unchecked?D. Social upheavals.3. What is the main idea of the second paragraph?A. Some plants have relative immunity to a great many diseases, while others have a susceptibility to them.4. According to the passage, some plant diseases can be prevented by ______.B. inoculation5. Which of the following statements is not true?D. Symptoms are always helpful in identifying diseases.二十九 "Don't Drink Alone" Gets New Meaning“不要在就餐时间以外饮酒”有了新含义In what may be bad news for bars a nd pubs………exposu to alcohol.1. Researchers have found that the risk of cancer in the mouth and neck is higher with peopleA who drink alcohol outside of meals.2. Which of the following is NOT the conclusion made by the researchers about "drinking with meals"?C It increases by 20 percent the possibility of cancer in all sites.3. Approximately how many drinks do the lowest-intake group average per day?A 3 drinks.4. Which cancer risk is the lowest among all the four kinds of cancer mentioned in the passage?B Laryngeal cancer.5. According to the last paragraph, tissue's lower exposure to alcoholD reduces the risk of laryngeal cancer.30.Silent and Deadly（无症状的却致命的）Transient ischemic attacks………the call that saves your life.1. Which of the following is NOT true of mini-strokes?A. The cause of them remains unidentified.2. To prevent mini-strokes from turning into major strokes, it is important toC. seek prompt medical treatment.3. The passage indicates that the symptoms of mini-strokesB. are frequently hard to recognize.4. All of the following may be signs of mini-strokes EXCEPT forD. severe headache caused by external injury.5. It can be inferred from the passage that mini-strokes are B. silent and deadly 31.Spacing in Animals（动物间隔距离）Flight DistanceAny observant person has noticed that..... as they cross a busy street.1. Which of the following is the most appropriate definition of Flight Distance?C. Distance between an animal and its enemy before fleeing.2. If an animal’s critical distance is penetrated, it willA. begin to attack.3. According to the passage, social distance refers toB. psychological distance.4. Which of the followi ng could best replace the word “band” in “We can think of it asa hidden band that contains the group” (in Paragraph 3)?A. Strip of land5. The example of the children holding hands when crossing the street in the last paragraph shows thatD. social distance is sometimes determined by outside factors.32.Fruit and vegetables juices as beneficial to healt（果汁和蔬菜与水果和蔬菜一样对人体有益）A European study has revealed that 100 percent fruit and vegetable juices……Science and Nutrition11 (2006).1. What on earth in both fruits and vegetables and their juices plays the most important role in reducing risk for diseases?D) Fiber and antioxidant.2. The judgment that fruit and vegetable juices are less beneficial to reducing chronic disease development is _____C) incorrect3. The review of the literature has documented the important role of fruit and vegetable juices in reducing the risk of various disease, ______ in particular.B) cancer and cardiovascular disease4. A large epidemiological study also found that using various 100% fruit and vegetable juices contributed to a reduced risk for ______.A) Alzheimer’s disease5. People who drink 3-4 servings of fruit and vegetable juices weekly may ______ risk of develo ping Alzheimer’s disease ______ those who drink only once a week.B) have three quarters lower, than33.In-line Skating and Injuries（轮滑和损伤）Increasing number of children are………Product Safety Commission.1. How many people took part in in-line skating in the US in 1995?C. Fewer than 17. 7 million.2. Which of the following is NOT mentioned as the most common reason for injuries?A. Skating with wrist and elbow wounds.3. What are the things experts might NOT advise youngsters to wear?D. Boots and thick clothes.4. “Truck-surfing” meansB. skating while holding onto a moving truck.5. According to the last paragraph, bumping with a motor vehicle took up--- of the deaths reported since 1992.A. over 80%34.Who Wants to Live Forever?（谁想永生）If your doctor could give you a drug that would let you live ……. figure those problems out.”1. I. Which of the following is NOT mentioned as one of the things that living longer might enable an individual to do?B. Having more education.2. Which of the following is implied in the sixth paragraph?A. Marriages in the US today are quite unstable.3. All of the following are possible effects living longer might have on working life EXCFPTB. More money would be used by employees in payment of their employees.4. An important feature of a society in which people live a long life is thatC. it lacks the curiosity to experiment what is new.5. Which of the following best describes Callahan’s attitude to anti-ageing technology?C. Reserved35.Single-parent kids do best（单亲幼儿最出色的）Single mums a re better at raising their……taken into account as well.1. With which of the following statements would the author probably agree?C. two-parent families produce less attractive children2. According to the passage, in what way does family conflict affect the quality of the offspring?A. the young males get less care3. What is the relationship between paragraph 4 and paragraph 5?B. experiment and result4. According to Hartley, which of the following NOT influenced by sexual conflict?D. the offspring’s body size5. According to the passage, people believe that a female’s reproductive strategy is influenced byC. ecological factors36.Dangerous Sunshine to Children（日光有害儿童健康）Two United Nations1 agencies warned on Tuesday ………. environment minister said.1. Why does the risk of developing skin cancers in children become greater and greater?C Because the earth’s protective ozone layer declines year after year.2. How many people die from skin cancers including melanoma all over the world every year?A An average of 66,000.3. What people are more likely to develop eye cataracts?C People living near the equator.4. All of the following articles may use some chemicals unfavorable for the preservation of the ozone layer EXCEPT______.D medicines5. The phrase “for good” in the last paragraph can be best replaced by______.A permanently37.Hypertension Drugs Found to Cut Risk of Stroke（发现高血压药品可降低中风的危险）Australian doctors declared Monday that………last couple of decades.1. How many people surviving the first stroke may suffer another attack during the following five years?C. 20% of them.2. Taking two blood pressure-lowering drugs may produce _____less risk of secondary strokes than taking only one such drug.D. about one fourteenth3. Which of the following is NOT a symptom left by strokes?A. Habitual sleeplessness.4. How many strokes may be reduced in a year if most of stroke patients can be treated in the way as the article recommends?B. 500,0005. What patients among those who have had a stroke will benefit greatly from taking blood pressure-lowering drugs?D. All of the above.38.Pregnancy Anomalies May Lower Breast Cancer Risk（怀孕异常会降低乳腺癌发生率）Certain abnormalities occurring in problem..... the study concluded.1. Which of the following may have NOTHING to do with a decline in breast cancer incidence?D. Experiencing serious morning sickness during the early period of pregnancy.2. According to the study, what on earth may play an important role in lowering breast cancer risk?B. The cha nges in the levels of hormones and other substances in the mother’s body.3. From the fifth paragraph we may infer that pregnant women whose blood pressure _____ may have the least risk of breast cancer.C. increases the most4. Which of the following is NOT a function of the placenta?C. Protecting the mother against breast cancer.5. It seems that Cohn is _____ of finding out the exact mechanisms at work.A. confident第三十九篇Sauna【桑拿浴】Ceremonialbathing1 has existed for..... this type of bath.1. Ceremonial bathing____.C) has various forms2. What is understood by some people to be the true sauna experience?B) Saunas with smoke.3. According to the third paragraph, saunas can do all of the following EXCEPT _D) curing asthma4. According to the fourth paragraph, sauna gives the skin a healthy glow because _A) pores are cleaned by sweat5. Who are advised not to take a sauna?D) All of the above.40.Some People Do Not Taste Salt Like Others（咸度因人而异）Low-salt foods may be harder for some people to …….. not limited to bitterness1. In paragraph 2, John Hays points out thatC. many people accept low-salt tasteless food reluctantly.2. The fourth paragraph describes brieflyA. how to select subjects and what to do in the research.3. The article argues that supertastersB. like snack foods as saltiness is their primary flavor.4. Which of the following applies to supertasters in terms of bitter taste?C. They prefer high-salt cheese, which tastes less bitter.5. What message do the last two paragraphs carry?A. Taste acuity is genetically determined.41.Kidney Disease and Heart Disease Spur Each Other（肾病和心脏病相互刺激）Hearts and kidneys: If one’s diseased,………McCullough says.1. How can one learn earlier whether he or she suffer simmering kidney disease?B By urine and blood tests.2. How many Americans suffer chronic kidney disease according to an estimation?A 1,9,000,000.3. How many Americans suffered end-stage kidney failure and required dialysis or a transplant to survive twenty years ago according to an estimation?D 100,000.4. What did the Archives of Internal Medicine call for doctors caring for heart patients to do?D To start rigorously checking out their patients' kidneys.5. Which of the following is NOT one of the three markers of kidney function?B Levels of the white blood cells in the blood.42.More about Alzheimer's Disease（老年性痴呆研究的新进展）Scientists have developed skin ...... have been disappointing.1. The newly developed skin tests may be used in the future is to allow doctors toC. predict who might get Alzheimer's disease.2. The passage indicates that Alzheimer's is a diseaseD. not easy to be diagnosed.3. Which of the following statements about the Alzheimer's disease is NOT true? death.D. There are many ways to deal with and cure the disease now.4. Which of the following about the relationship between Alzheimer's and dementia is true?A. Dementia is one of the signs of Alzheimer's5. The last paragraph implies that the diagnostic testC. may not be proven valid smoothly.cation of Students with Vision Impairments（视力损伤的学生教育）This is special designed education…… academic skills.1.Various adaptive aids are used toB) help children see more clearly,read books and soon.rge-print books are those books whichB) have large words in them.3.Marry blind students prefer listening to books becauseC) this can save time.4.“Orientation and mobility training’’is meant to teach blind and partially sighted childrenC)how to move around without other people’s help.5.It may be good for children with vision impairments to live in special schools because these schoolsA) can save them the trouble of coming from and going back to their homes.44.Water PollutionThe demand for freshwater rises continuously as …….（1. 5 million gallons） of oil.1. According to this passage, which of the following statements is true of yearly water consumption?B. Most water is used for farming.2. Paragraph 2 suggests all of the following EXCEPT thatC. EPA is responsible for causing serious water pollution in America.3. Water runoff causes fish to die partly becauseD. the fast-growing algae have used up the oxygen in the water where they live.4. An important idea of paragraph 4 is thatA. cutting down too many trees may also cause water pollution.5. The main subject of the last paragraph isC. Oil Spills and Pollution of the Sea.45.DNA Fingerprinting(DNA指纹)DNA is the genetic material found within the ………. DNA fingerprint database1. According to the essay, we can find chromosomesC. in a sheep.2. DNA fingerprinting is more often used forB. providing evidence in court investigations.3. When your brother looks exactly like you, your complete DNA may beA. exactly like his.4. Some people believe that using a DNA fingerprint may not be so reliable becauseC. mistakes are possible when researchers explain what have come of their tests5. This essay talks about DNA fingerprinting concerning the following aspects EXCEPTD. possible danger in drawing a DNA sample from the human body.46.Malnutrition（营养不良）“Much of the sickness and death attributed ……for pregnant women.1. What is the cause of much of the sickness and death?B. Malnutrition.2. What is the writer’s attit ude toward the serious situation?C. We should act.3. How many countries have made plans of action for nutrition?A. 98.4. Which of the following is NOT the harm of lacking iron?C. Traffic accidents.5. Which of the following is NOT mentioned as a remedy for iron deficiency?C. Drinking coffee soon after meals.47.Drug resistance fades quickly in key AIDS drug（治疗AIDS药物的抗药性会很快消失）One of the main weapons to prevent ……hit by the virus.1. What effect does nevirapine have?D It may prevent passing HIV infection from mothers. on to their newbornsduring delivery2. Why does HIV resistance against nevirapine build very quickly even when the drug is used alone just once?C Because other drug are not present to kill the virus particles that survive nevirapine3. When may a woman start her nevirapine based treatment if she gets the single dose of nevirapine at delivery？C she has to wait at least six months after that nevirapine exposure4. We may learn from this. passage that HIV resistance against nevirapine ____.A lasts only for about a half year and fades quickly5. Generally speaking, the author's attitude towards the use of nevirapine is＿．B positive48.IQ-Gene（智商基因）In the angry debate over how much.....whole box of salt.1. In the beginning of paragraph one we are told that scientists can not agreeC. how much of IQ comes from genes.2. What does “some ”in the second sentence of paragraph one stands for?D. Genes.3. A gene for chopsticks flexibility is found to beA. unrelated to the ability to use chopsticks.4. Plomin's IQ-gene study is similar to the chopsticks gene finding in thatA. there may not be a causal link between gene and intelligence.5. What does Feinberg mean by saying “I would take these findings with a whole box of salt”?D. He doubts the findings very much.49.A Gay Biologist（一名同性恋生物学家）Molecular biologist Dean Hammer..... this sort of research1. The first paragraph describes Hamer'sA. looks, hobbies and character.2. Hamer was aD. biologist.3. What is Hamer doing now?B. He is exploring the role of genes in deciding one's personality.4. What happened to Hamer's research interest?C. He turned to behavioral genetics.5. According to Hamer, what was one of the main reasons for him to choose homosexual behavior as his research subject?B. He was curious about it as a scientist.50. Million Americans Suffer from Social Anxiety DisorderSocial anxiety disorder prevents.....Ross noted.1. Which is NOT true of people with social anxiety disorder?D They tend to judge or criticize other people.2. The symptoms of social anxiety disorder include all the following EXCEPT________.B sore throat.3. People with social anxiety disorder are known for their fear of _______.D facing social or performance situations.4. What do people with social anxiety disorder think of their fear?A They think it's beyond their control.5. It can be seen from the last paragraph that treatment of the disorder _____D can lead to improvement in the sufferers' lives.18、Exercise Can replace insulin for elderly diabetics1、How could most eldly type 2 diabetics stop taking insulin?C、By doing brisk exercise for half an hour at least threetimes a week2、Physical exercise may increase body ability to utilize insulin by __B、30 percent3、The subjects of the research tests conducted at the Copenhagen .. ..inclludedD\both A and B4、To what a degree have diebetics ti exercise in order to achieve the desire effect?A、To the degree where they begin to sweat5、according to dela,among most diabetics the importance of exercise is---C. less understood than。

学术英语写作杨新亮课文翻译

学术英语写作杨新亮课文翻译In recent years there has been considerable interest in explorin g the nature of expert performance across domains ( e.g.,Ericsson, Hoffman,Charness,Feltovich.2006;Ericsson Williams, 2007).For example,scientists with an interest in sports have analyzed the perceptualcognitive skills underpinning anticipation in this domain and identified how these processes are acquired through prolonged engagement in practice (for reviews, see Hodges, Huys, Starkes, 2O 07: Williams Ford. 2008 : Williams Ward, 2007 ).The scientific study of skill acquisition has along history in experimental psychology,dating back to the early st udies of Bryan and Harter (1899).In more recent times, Poulton (19 57) was the firstto systematically discriminate between different types of anticipati on judgements using experimetal methods common to this discipl ine. The scientific study of anticipation as a field of inquiry in its ow n right in sport psychologyhas a much shorter history, emergingprimarily in 1970s ( far a historical overview, see Williams. Davids. Williams, 1999).The majority of sport psychologists work in multi_d isciplinary departments where research in traditional discipline area s,such as physiology. psychology. and biomechanics, often develops somewhat independently of academic endeavour within the main disciplines themselves. The empirical findings that have been reported on anticipation in the field of sport psychology could therefore contribute to the generation of new knowledge on this topic in the parent discipline area, and part icularly in applied cognitive psychology.近年来，在探索专家性能的跨域的性质得到了相当大的兴趣（例如，爱立信，霍夫曼，feltovich查尼斯， 2006；爱立信威廉姆斯，2007）。

Thermal emission from three-dimensional arrays of gold nanoparticles

a r X i v :c o n d -m a t /0602674v 1 [c o n d -m a t .o t h e r ] 28 F eb 2006Thermal emission from three-dimensional arrays of goldnanoparticlesVassilios Yannopapas ∗Department of Materials Science,School of Natural Sciences,University of Patras,GR-26504Patras,Greece Abstract We study the blackbody spectrum from slabs of three-dimensional metallodielectric photonic crystals consisting of gold nanoparticles using an ab initio multiple-scattering method.The spectra are calculated for diﬀerent photonic-crystal slab thicknesses,particle radii and hosting materials.We ﬁnd in particular that such crystals exhibit a broadband emission spectrum above a speciﬁc cutoﬀfrequency with emissivity of about 90%.The studied photonic crystals can be used as eﬃcient selective emitters and can therefore ﬁnd application in thermophotovoltaics and sensing.The main feature of photonic crystals is the ability to tailor the photon density of states and this way control the spontaneous emission of light,aiming at the realization of new opto-electronic devices.In this context,there has been considerable eﬀort to design and fabricate photonic crystals which allow for control of thermal emission of light,i.e.thermally driven spontaneous emission,promising applications in imaging,sensing and most importantly,in thermophotovoltaics(TPV).1,2,3,4,5,6,7,8,9Control of thermal emission can also be achieved by means of microstructured engineering on silicon10,11,12,13or metal surfaces.14Depending on the type of application,photonic crystals and structured surfaces can act as narrow-or wide-band,directional or isotropic thermal emitters.For example,in TPV applications15a quasi-monochromatic emission is preferable whilst in radiation cooling16a broad emission spectrum is desired.In this work we investigate the emission properties of three-dimensional metallodielectric photonic crystals consisting of gold nanoparticles.Weﬁnd,in particular, that the emission spectrum of these crystals can be such that photons are emitted in all directions only when their energies lie above a speciﬁc cutoﬀfrequency,with emissivity as large as90%.Photonic crystals of spherical scatterers have been theoretically studied using multiple scattering theory17,18which is ideally suited for the calculation of the transmission,reﬂection and absorption coeﬃcients of an electromagnetic(EM)wave incident on a composite slab consisting of a number of planes of non-overlapping particles with the same two-dimensional (2D)periodicity.For each plane of particles,the method calculates the full multipole expan-sion of the total multiply scattered waveﬁeld and deduces the corresponding transmission and reﬂection matrices in the plane-wave basis.The transmission and reﬂection matrices of the composite slab are evaluated from those of the constituent layers.Having calculated these matrices one can evaluate the transmittance T(ω,θ,φ),reﬂectance R(ω,θ,φ),and from those two,the absorbance A(ω,θ,φ)of the composite slab as functions of the incident photon energy ωand incident anglesθandφ.Transmittance and reﬂectance are deﬁned as the ratio of the transmitted,respectively the reﬂected,energyﬂux to the energyﬂux as-sociated with the incident wave.The method applies equally well to non-absorbing systems and to absorbing ones.In terms of speed,convergence and accuracy,the multiple scattering method is the best method to treat photonic structures of spherical particles.The emittanceE(ω,θ,φ)is calculated indirectly by application of Kirchoﬀ’s law,19,20i.e.fromE(ω,θ,φ)=A(ω,θ,φ)=1−R(ω,θ,φ)−T(ω,θ,φ)(1) Note that recent direct calculations of the thermal emission from photonic crystals have veriﬁed the validity of Kirchoﬀ’s law for the case of photonic crystals.21 In this work we deal with gold spheres with radius of a few nanometres.Traditionally, the gold spheres are treated as plasma spheres whose dielectric function is given by Drude’s formulaǫp(ω)=1−ω2pω(ω+iτ−1b )−ω2pdielectric function,i.e.Eq.(4),has successfully reproduced experimentally obtained light absorption and scattering spectra of monolayers of gold nanoparticles.27 To begin with,we consider an fcc photonic crystal whose lattice sites are occupied by gold nanospheres of radius S=5nm.The lattice constant of the crystal is a=19.11nm corresponding to a volumeﬁlling fraction occupied by the spheres,f=0.3.The spheres are supposed to be suspended in air.The crystal is viewed as a succession of planes of spheres(layers)parallel to the(001)surface of fcc.In Fig.1we show the transmittance, reﬂectance and absorbance vs energy for light incident normally on aﬁnite slab of the crystal consisting of128layers of spheres.We observe that for energies above2.2eV almost all light (92%-98%)that is incident on the crystal slab is absorbed from the gold spheres.Therefore, from Kirchoﬀ’s law,i.e.E(ω,θ,φ)=A(ω,θ,φ),we can infer that the blackbody radiation is strong above this energy.Indeed,the blackbody radiation intensity of the photonic crystal is given byI P C(ω,θ,φ,T)=E(ω,θ,φ)I BB(ω,T)(5) where I BB(ω,θ,φ,T)is the blackbody radiation intensity(Planck distribution)I BB(ω,T)= ω3exp( ω/k B T)−1.(6)k B is the Boltzmann constant and c is the speed of light in vacuum.In a metal particle of nanoscale radius,there are two principal sources of light emission/absorption:theﬁrst one is the dipole oscillations due to the surface plasmon resonances and the second is the interband transitions that take place in bulk gold contributing to its dielectric function.In terms of theﬁrst source of emission,the crystal can be viewed as a lattice of interacting oscillating dipoles where each one of the dipoles emits light around the surface plasma resonance frequencyωSP=ωp/√interested in the spectral hemispherical (SH)radiative properties of the photonic crystal.More speciﬁcally,we are interested in the SH emissivity s (ω)which is the ratio of the SH emissive power of a photonic-crystal slab to the SH emissive power of a perfect blackbody at the same temperature T .For a slab inﬁnitely extended in two dimensions:s (ω)= 2π0dφ π/20dθI P C (ω,θ,φ,T )cos θsin θπ 2π0dφ π/2dθE (ω,θ,φ)cos θsin θ(7)Note that E (ω,θ,φ)in the above equation is the arithmetical average of both polarization modes.In Fig.2we show the SH emissivity from slabs of the photonic crystal of Fig.1for diﬀerent slab thicknesses (number of layers).It is evident that as the number of layers increases the SH emissivity increases accordingly until it reaches a saturation plateau for slabs of 64layers and above.Indeed,for energies above 2.2eV the emissivity curves for 64and 128layers are practically the same.This fact implies that,if we measure the emission from one of the surfaces of a 128layers-thick slab,then the emitted radiation must be coming from the 64outmost layers (relative to a given surface)whilst radiation coming from the 64innermost layers is almost totally absorbed from the 64outmost layers by the time it reaches the surface of the slab.The most important ﬁnding of Fig.2is the fact that the photonic crystal behaves more or less as gray body (emissivity ranging from 88%to 92%)for energies above 2.2eV while,at the same time,emits small amounts of radiation for energies below this cutoﬀ.A similar emission spectrum is observed for the Salisbury screen 13but with signiﬁcantly lower values of the SH emissivity.So far,we have assumed that the gold nanospheres are suspended in air.In order to provide a manufacturable structure it is necessary to examine the case where the spheres are embedded in a host material of dielectric function ǫh .In Fig.3we show the SH emissivity from a 64-layer slab of an fcc photonic crystal of gold nanospheres with f =0.3where the spheres are surrounded by air (ǫh =1),silica (ǫh =1.88)and gelatine (ǫh =2.37).The introduction of a host material does not change the picture drastically except that it lowers the emission cutoﬀenergy.This is due to thelowering of the surface plasmon frequency according to ωSP =ωp /√emission region and a distinct local minimum appears.This is evident from the emissivity spectra of Fig.3for silica and gelatine host materials.The shift of the surface plasmon energy with respect to the host materialǫh allows for tuning of the cutoﬀenergy so that it coincides with the band gap of the photodiode of a TPV device.Next we study the eﬀect of the volumeﬁlling fraction f on the emission properties of the photonic structure under study.In Fig.4we show the SH emissivity spectra for photonic crystals of diﬀerent values of f.We have kept the lattice constant the same and changed the sphere radii accordingly.Note that for each value of f we obtain a diﬀerent value of τ−1from Eq.(3).We observe that the maximum emissivity in the region above the cutoﬀenergy is achieved for f=0.3.Since our calculations show that the SH reﬂectivity assumes higher values for f=0.5,0.7,the radiation emitted from the innermost layers is reﬂected back and reabsorbed before it reaches the surface of the slab.Finally we address the issue of spatial order/disorder of the photonic crystal under investigation.As it has been both theoretically30,31and experimentally32shown,the pres-ence of disorder does not changes practically the absorption/emission properties of three-dimensional photonic crystals of metal nanoparticles since these quantities mostly depend on single sphere properties such as surface plasmon resonances,and less on the particular spatial arrangement of the spheres.Note that this not true for one-or two-dimensional structures,e.g.a linear chain or a monolayer of nanospheres,where the presence of dis-order changes dramatically the absorption/emission spectra.31So,since we deal with a three-dimensional structure,a disordered crystal might be easier and cheaper to fabricate.In summary,we have shown that a metallodielectric crystal consisting of gold nanospheres can act as a90%gray body for energies above a cutoﬀ.The cutoﬀfrequency can be tuned by appropriate choice of the material hosting the nanospheres.Optimal emissivity is obtained for moderate volumeﬁlling fractions and slab thicknesses.ACKNOWLEDGEMENTSThis work was supported by the‘Karatheodory’research fund of University of Patras.∗Electronic address:vyannop@upatras.gr1 C.M.Cornelius and J.P.Dowling,Phys.Rev.A59,4736(1999).2S.Y.Lin,J.G.Fleming,E.Chow,J.Bur,K.K.Choi,and A.Goldberg,Phys.Rev.B62, R2243(2000).3J.G.Fleming,S.Y.Lin,I.El-Kady,R.Biswas,and K.M.Ho,Nature(London)417,52(2002). 4M.U.Pralle,N.Moelders,M.P.McNeal,I.Puscasu,A.C.Greenwald,J.T.Daly,E.A.Johnson, T.George,D.S.Choi,I.El-Kady,and R.Biswas,Appl.Phys.Lett.81,4685(2002).5S.Y.Lin,J.G.Fleming,and I.El-Kady,Opt.Lett.28,1909(2003).6I.Celanovic,F.O’Sullivan,M.Ilak,J.Kassakian,and D.Perreault,Opt.Lett.29,863(2004).7 A.Narayanaswamy,and G.Chen,Phys.Rev.B70,125101(2004).8S.Enoch,J.-J.Simon,L.Escoubas,Z.Elalmy,F.Lemarquis,P.Torchio,and G.Albrand, Appl.Phys.Lett.86,261101(2005).9M.Florescu,H.Lee,A.J.Stimpson,and J.Dowling,Phys.Rev.A72,033821(2005).10H.Sai,H.Yugami,Y.Akiyama,Y.Kanamori,and K.Hane,J.Opt.Soc.Am.A18,1471 (2001).11S.Maruyama,T.Kashiwa,H.Yugami,and M.Esashi,Appl.Phys.Lett.79,1393(2001).12 F.Marquier,K.Joulain,J.P.Mulet,R.Carminati,and J.J.Greﬀet,mun.237,379(2004).roche,F.Marquier,R.Carminati,and J.J.Greﬀet,mun.250,316(2005).14 F.Kusunoki,T.Kohama,T.Hiroshima,S.Fukumoto,J.Takahara,and T.Kobayashi,Jpn.J.Appl.Phys.43,5253(2004).15M.Zenker,A.Heinzel,G.Stollwerck,J.Ferber,and J.Luther,IEEE Trans.Electron.Devices 48,367(2001).16 C.W.Hoyt,M.P.Hasselbeck,M.Sheik-Bahae,R.I.Epstein,S.Greenﬁeld,J.Thiede,J.Distel,and J.Valencia,J.Opt.Soc.Am.B20,1066(2003).17N.Stefanou,V.Karathanos and A.Modinos,J.Phys.:Condens.Matter4,7389(1992).18N.Stefanou,V.Yannopapas,and A.Modinos,mun.113,49(1998);ibid 132,189(2000).19S.M.Rytov,Yu.A.Kravtsov,V.I.Tatarskii,Principles of statistical radiophysics,Vol.3: Elements of randomﬁelds(Springer,Berlin,1989).20J.J.Greﬀet and M.Nieto-Vesperinas,J.Opt.Soc.Am.A15,2735(1998).21 C.Luo,A.Narayanaswamy,G.Chen and J.D.Joannopoulos,Phys.Rev.Lett.93,213905(2004).22R.B.Johnson and R.W.Christy,Phys.Rev.B 6,4370(1972).23S.Norrman,T.Andersson,C.G.Granqvist,and O.Hunderi,Phys.Rev.B 18,674(1978).24 F.Abel`e s,Y.Borensztein,and T.L´o pez-Rios,Festk¨o rperprobleme (Advances in Solid State Physics)vol 24(Braunschweig:Vieweg)p.93(1984).25M.M.Wind,P.A.Bobbert,J.Vlieger,and D.Bedeaux,Physica A 143,164(1987).26P.A.Bobbert and J.Vlieger,Physica A 147,115(1987).27N.Stefanou and A.Modinos,J.Phys.:Condens.Matter 3,8135(1991).28N.Stefanou and A.Modinos,J.Phys.:Condens.Matter 3,8149(1991).29V.Yannopapas,A.Modinos,and N.Stefanou,Phys.Rev.B 60,5359(1999).30A.Modinos,V.Yannopapas,and N.Stefanou,Phys.Rev.B 61,8099(2000).31V.Yannopapas,A.Modinos,and N.Stefanou,Opt.Quant.Elec.34,227(2002).32K.P.Velikov,W.L.Vos,A.Moroz,and A.van Blaaderen,Phys.Rev.B 69,075108(2004).1234560.00.20.40.60.81.0Photon Energy (eV) Transmittance Reflectance Absorbance FIG.1:Transmittance,reﬂectance,and absorbance of light incident normally on a 128-layers thick slab of a fcc crystal consisting of gold spheres (S =5nm)in air (ǫh =1),with f =0.3.1234560.00.20.40.60.81.0E m i s s i v i t y Photon Energy (eV) N=128 N= 64 N= 32 N= 16 N= 8 N= 4 N= 2 N= 1FIG.2:SH emissivity for diﬀerent numbers of layers (slab thicknesses)of the photonic crystal described in Fig.1.1234560.00.20.40.60.81.0E m i s s i v i t y Photon Energy (eV) In Air In SiO In gelatine FIG.3:SH emissivity of a 64-layer thick slab of an fcc crystal of gold spheres (S =5nm)in air (ǫh =1-solid line),silica (ǫh =1.88-dashed line)and gelatine (ǫh =2.37-dotted line),with f =0.3.We have assumed that the host medium surrounding the spheres also covers the whole space.1234560.00.20.40.60.81.0E m i s s i v i t y Photon Energy (eV) f=0.1 f=0.3 f=0.5 f=0.7FIG.4:SH emissivity of a 64-layer thick slab of an fcc crystal of gold spheres (S =5nm)in air,for diﬀerent volume ﬁlling fractions f (ﬁxed lattice constant and diﬀerent sphere radii).。

科技英语阅读(李健版)翻译U7

By far the most common genetically modified (GM) organisms are crop plants. But the technology has now been applied to almost all forms of life, from pets that glow under UV light to bacteria which form HIV- blocking "living condoms" and from pigs bearing spinach genes to goats that produce spider silk.到目前为止最常见的转基因生物体是农作物。

然而，这项技术现在已经应用于几乎所有形态的生命,从宠物在紫外线照射下发光到构成HIV-blocking 的“活的安全套”的细菌,从继承菠菜基因的猪到生产蜘蛛丝的山羊。

GM tomatoes, as puree, first appeared on British supermarket shelves in 1996 (a different fresh GM tomato first appeared in the US in 1994), but the consumer furore that surrounded GM technology did not erupt until February 1999.This was because a controversial study suggested that a few strains of GM potatoes might be toxic to laboratory rats.Those experiments, subsequently criticised by other experts, were carried out in Scotland by biochemist Arpad Pustzai.转基因西红柿酱, 在1996年第一次出现在英国的超市货架上(1994年不同的新鲜番茄在美国首次出现),但直到1999年2月消费者对基因技术的愤怒才爆发。

Radiative Processes in Microquasars

a r X i v :a s t r o -p h /0209186v 2 11 S e p 2002Radiative Processes in MicroquasarsJuri Poutanen 1&Andrzej A.Zdziarski 21Astronomy Division,P.O.Box 3000,90014University of Oulu,Finland 2Centrum Astronomiczne im.M.Kopernika,Bartycka 18,00-716Warszawa,Poland Abstract.Recent advances in the X-ray and soft γ-ray observations of accreting black holes and microquasars,in particular,are reviewed.The radiative processes responsible for the emission are discussed brieﬂy.The hybrid thermal/nonthermal Comptonization model is shown to describe well the observed broad-band spectra.We also comments on alternative phenomenological and physical models that are used to describe the X/γ-ray spectra of accreting black holes.Among those are the “standard”model (i.e.disk-blackbody plus a power-law),pexrav ,bulk motion Comptonization,and synchrotron emission from the jet.1.Introduction Accreting black holes radiate in the two main spectral states which we refer to later as hard and soft (see Fig.1).The hard state is characterized by a power-law–like spectrum which abruptly cuts oﬀat ∼100keV.The energy output is dominated by the 100keV photons [2].Such a spectrum is interpreted as Comptonization by thermal electrons in the inner hot disk or active magnetic corona above the accretion disk (e.g.[3,4,5]).A weak MeV tail observed in Cyg X-1is probably a signature of non-thermal electrons in the source [6,7,8].In the soft state the emission is dominated by the black-body–like component peaking at a few keV with a power-law–like component above 30keV extending up to 1MeV or even higher [2,8,9,10].These spectra cannot be ﬁtted with thermal Comptonization models and require the radiating electrons to have a signiﬁcant non-thermal fraction [7,11,12].2.Spectral Modeling2.1.Cygnus X-1A weak MeV tail observed in Cyg X-1in its hard state already shows us that the emitting electrons cannot be purely thermal (see left panel of Fig.2).An obvious generalization is to assume that there is a non-thermal tail in the electron distribution that is produced by some acceleration process (e.g.[6]).The soft state data (even below 1MeV)could not be ﬁtted at all with thermal models.Modeling of the spectral transitions with a generalized hybrid thermal/non-thermal model eqpair [7,13]predicted a stronger power-law–like tail in the soft state extending up to 10MeV.CGRO /COMPTEL observations conﬁrmed the existence of this tail:the decrease of the hard X-ray luminosity was accompanied by the increase of the soft γ-ray luminosity [8].In the context of the hybrid Comptonization model,the power-law is a result of single Compton scattering oﬀnon-thermal2Poutanen&ZdziarskiFigure1.A collection of broad-band spectra of Cyg X-1.The solid curves give the best-ﬁt Comptonization models(thermal in the hard state,and hybrid,thermal-nonthermal in the other states).From[1].Figure2.Left:Components of the eqpairﬁt to the hard state CGRO data of Cyg X-1.The long dashes,short dashes,and dots correspond to the unscattered blackbody,scattering by thermal electrons,and Compton reﬂection,respectively.The solid curve is the total spectrum.Scatter-ing by the nonthermal electrons accounts for the high-energy tail above the thermal-Compton spectrum given by the short dashes,starting at∼1MeV.Right:Components of the eqpairﬁt to the BeppoSAX-CGRO data for the soft state of Cyg X-1.The curves have the same meaning as in the left panel.The dots/dashes correspond to the scattering by nonthermal electrons.All spectra are intrinsic,i.e.,corrected for absorption.From [8].population of electrons(see right panel in Fig.2).A cutoﬀat about10MeV (depending on the compactness of the source)should appear in the spectrum due to the absorption of theγ-rays by softer photons resulting in pair production.2.2.GRS1915+105In spite of the fact that microquasar GRS1915+105show dramatic variability pattern,almost all its hard X-ray spectra are remarkably similar.During eight (out of nine)observations with the CGRO/OSSE the source showed a simple power-law–like spectrum in the50–500keV band with photon indexΓ≈3[12]. Only in one occasion(when the X-rayﬂux was very high),the hard X-ray spec-Radiative Processes in Microquasars3Figure3.Left:Fits to simultaneous RXTE-OSSE spectra of GRS1915+105from VP619(1997 May14–20)and VP813(1999April21–27)with the hybrid Comptonization model eqpair.The dashed and solid curves show the models of the observed spectra and the unabsorbed spectra, respectively.Right:(a)Components of theﬁt to the VP619data.All spectra are intrinsic,i.e.,corrected for absorption.The dotted,dot-dashed and dashed curves give the unscattered blackbody com-ponent,the scattered spectrum,and the component due to Compton reﬂection and Fe Kαﬂuorescence,respectively.The solid curve is the total spectrum.The thin long-dashed curve shows the best-ﬁt thermal Comptonization model,which lies much below the data above100 keV.(b)The total model spectrum and the corresponding two components for the VP813data. The cutoﬀat∼10MeV is due to photon-photon pair production absorption.From[12].trum was much harderΓ≈2.3and theﬂux was low.We note here that in all observations the source has a much softer spectrum than the normal hard state of Cyg X-1,i.e.it was always in the soft state.There is no signature of the high-energy cutoﬀin the data.The eqpair model gives a good description of the data (see Fig.3)indicating that about10-20%of the total power goes to accelerate non-thermal electrons.The C/χ-state[14]diﬀers,however,from the B/γ-state in that the20-200keV tail is produced by thermal Comptonization in the former and by non-thermal Compton scattering in the later.3.Old and New Alternatives3.1.The“standard”modelThe black body looking soft component is associated with the optically thick ac-cretion disk by most of the researchers.The broad-band spectra are oftenﬁtted by the“standard”model consisting of a disk-blackbody(soft component)and a power-law(hard).There are numerous problems with such modeling.First,a black body is a bad representation of the spectrum expected from the accretion disk(e.g.[15]).Real data also show that the soft bumps in the Cyg X-1soft state[11]and GRS1915+105[12]cannot beﬁtted by a black body(or multi-color disk).Thermal Comptonization of a blackbody is a much better description of these spectra.Second,a power-law,even exponentially folded,is a very bad representation of the Comptonization spectra.At the lower end,Comptonization4Poutanen&Zdziarskispectrum cuts oﬀbelow the seed photon energy while a power-law has no break there.The normalization of the blackbody thus can be underestimated by a large factor(see e.g.[16]).The conclusions(e.g.variations of the inner disk radius) resulting fromﬁtting the data with this“standard”model thus should be taken with a grain of salt.At the higher end,the(thermal)Comptonization spectrum has a much sharper cutoﬀthan an exponentially folded power-law.This diﬀerence in the spectral shape is important when we model the broad-band spectra from accreting black holes with the later model adding a Compton reﬂection component(model pexrav [17]from XSPEC)since the amplitude of the reﬂection component strongly de-pends on the assumed shape of the underlying continuum.Thus,we would advise not to use pexrav when modeling Comptonization spectra close to the black body or to the high energy cutoﬀ.3.2.X-rays from the jet?A very interesting correlation between radio and X-rayﬂuxes has been discovered recently[18,19,20].There are two possible origins of this correlation.One is that the level of X-ray emission is related to the rate of ejection of radio-emitting clouds,forming a compact jet(e.g.,[19,21]).Another is that the X-ray emission of black hole binaries is dominated by the synchrotron emission of the jet[22,23].We note here there are many strong arguments against the second interpre-tation.The broad-band X/γ-ray spectra of black hole binaries in the hard state are very well modeled by thermal Comptonization and Compton reﬂection(e.g., [24,25,26,27]).The presence of reﬂection implies that the X-ray emission is not strongly beamed away from the disk.The thermal-Compton origin of the primary X-ray emission is strongly supported by a remarkable uniformity of the both energy and shape of the high-energy cutoﬀs of black hole binaries in the hard state observed by OSSE[10].This cutoﬀis naturally accounted for by thermo-static properties of thermal Comptonization as well as e±pair production(e.g., [5]),as it corresponds to the transition to relativistic temperatures.At higher temperatures,cooling becomes extremely eﬃcient and copious pair production starts.This reduces the energy available per particle leading to the tempera-ture decrease.On the other hand,m e c2plays no particular role for non-thermal synchrotron emission(cf.variable cutoﬀenergy duringﬂares in blazars).Thus, accounting for the observed cutoﬀenergies requiresﬁne-tuning of product of the square of the maximum electron energy and the magneticﬁeld strength in the non-thermal synchrotron models.In addition,the jet model has problems repro-ducing the actual shape of the cutoﬀ.For example,the synchrotron model of the hard state of Cyg X-1(seeﬁg.3a in[23])when matched to the100keVﬂux overestimates the1MeVﬂux(see[8])by a factor of8.An additional evidence against a substantial part of X-rays being non-thermal synchrotron is provided by spectral variability.In the case of Cyg X-1,the ASM/BATSE data show spectral pivoting around∼40–50keV(see[1]and Fig.4).The characteristic variations of the power-law slope∆Γfrom those data is∼0.2–0.3.This power-law spectral variability extended to15GHz would imply a huge variability of the radioﬂux,by several orders of magnitude.However,the range of the variability of the15GHzﬂux correlated with the ASMﬂux is by a factor of several,basically the same as the range of the variability of the ASM ﬂux itself[20].If both radio and X-rays were due to non-thermal synchrotron emission,their observed variability pattern should yield the rms in X-rays virtu-ally independent of energy.This is clearly in strong disagreement with the dataRadiative Processes in Microquasars5Figure4.Left:The rms variability in the hard state of Cyg X-1in one-day averaged data from the RXTE/ASM and CGRO/BATSE[1].The model curve corresponds to a power-law pivoting with∆Γ≃0.2around the energy which has a Gaussian distribution around45keV(see[28]for details).Right:Count rate during the two outbursts of Cyg X-1on1999April21in the BATSE large area detectors energy channels1–3(corresponding to approximately20–50keV,50–100keV,100–300 keV).Count rates are higher in softer channels.The count rate is summed over two detectors closest to the line of sight to Cyg X-1.Dashes,dots,and dash/dots show the background in channels1,2,3,as seen by two detectors looking away from Cyg X-1.From[32].shown in Fig.4,and,in particular,with the ASM1.5–3keVﬂux being strongly anticorrelated with the100–300keVﬂux from BATSE[1].The amplitude of Compton reﬂection and the iron line imply that dense and rather cold material occupies a solid angle∼πas viewed from the X-ray source. Smearing of these components and the observed correlations with the spectral slope[28,29,30]clearly identiﬁes the reﬂector with the accretion disk and implies the origin of the continuum emission within30–100gravitational radii from the black hole which would also be consistent with rapid X-ray variability.The above arguments also rule out the dominant contribution of the nonthermal Compton emission[31]from the jet to the observed hard state spectra of black holes.All these arguments strongly support the interpretation of the correlated radio emission as being due to ejection of clouds from the X-ray source which could be similar to coronal mass ejections(CME)observed at the Sun.The recently discovered strong X/γ-raysﬂares from Cyg X-1[32,33]could be the extremes of such an activity.The right panel in Fig.4shows theﬂaring activity of Cyg X-1in April1999.The episode D–E shows strongﬂare in the20–100keV band with a weaker activity above100keV and no detectable signal above300keV. This indicates that there exist at least two independent spectral components(see [32]):one could be related to the inner hot disk or the magnetized corona,while another to the base of the jet.3.3.Bulk motion ComptonizationThe power-law like spectra of black holes in the soft state were interpreted as resulting from bulk motion Comptonization in the convergingﬂow[34,35,36]. The speciﬁc feature of that model is a cutoﬀat∼100–200keV.(We note here6Poutanen&Zdziarskithat the XSPEC version of the model bmc has no cutoﬀbuilt in.)The data show no signatures of the cutoﬀat least up to500keV in GRS1915+105[12]and up to10MeV in Cyg X-1[8].This supports their non-thermal origin and strongly rules out a signiﬁcant contribution from the bulk motion Comptonization.(See further discussion in[2,12].)AcknowledgmentsThis work was partly supported by the Academy of Finland and grants from the Polish Committee for Scientiﬁc Research(5P03D00821,2P03C00619p1,2)and the Foundation for Polish Science.References1.Zdziarski A.A.,Poutanen J.,Paciesas W.S.,&Wen L.,2002,ApJ,578,in press(astro-ph/0204135).2.Zdziarski A.A.,2000,in IAU Symp.195,Highly Energetic Physical Processes and Mecha-nisms for Emission from Astrophysical Plasmas,eds.P.C.H.Martens,S.Tsuruta&M.A.Weber(San Francisco:ASP),153(astro-ph/0001078).3.Poutanen J.,Krolik J.H.,&Ryde F.,1997,MNRAS,292,L21.4.Beloborodov A.M.,1999,ApJ,510,L123.5.Malzac J.,Beloborodov A.M.,&Poutanen J.,2001,MNRAS,326,4176.Li H.,Kusunose M.,&Liang E.P.,1996,A&AS,120C,167.7.Poutanen J.,&Coppi P.S.,1998,Physica Scripta,T77,57.8.McConnell M.L.,et al.,2002,ApJ,572,984.9.Poutanen J.,1998,in Theory of Black Hole Accretion Disks,eds.M.A.Abramowicz,G.Bj¨o rnsson&J.E.Pringle(Cambridge Univ.Press:New York),p.100.10.Grove J.E.,et al.,1998,ApJ,500,899.11.Gierli´n ski M.,Zdziarski A.A.,Poutanen J.,Coppi P.S.,Ebisawa K.,&Johnson W.N.,1999,MNRAS,309,496.12.Zdziarski A.A.,Grove J.E.,Poutanen J.,Rao A.R.,&Vadawale S.V.,2001,ApJ,554,L45.13.Coppi P.S.,1999,in ASP Conf.Ser.Vol.161,High Energy Processes in Accreting BlackHoles,eds.J.Poutanen&R.Svensson(San Francisco:ASP),375.14.Belloni T.,et al.,2000,A&A,355,271.15.Merloni A.,Fabian A.C.,&Ross R.R.,2000,MNRAS,313,193.16.Vilhu O.,Poutanen J.,Nikula P.,&Nevalainen J.,2001,ApJ,553,L51.17.Magdziarz P.,&Zdziarski A.A.,1995,MNRAS,273,837.18.Brocksopp C.,et al.,1999,MNRAS,309,1063.19.Corbel S.,et al.,2000,A&A,359,251.20.Gallo E.,Fender R.,&Pooley G.G.,2002,these proceedings.21.Mirabel I.F.,et al.1998,A&A,330,L9.22.MarkoﬀS.,Falcke H.,&Fender R.,2001,A&A,372,L25.23.MarkoﬀS.,Nowak M.,Corbel S.,Fender R.,Falcke H.,2002,these proceedings.24.Gierli´n ski M.,Zdziarski A.A,Done C.,Johnson W.N.,Ebisawa K.,Ueda Y.,Haardt F.,&Phlips B.F.,1997,MNRAS,288,95825.Zdziarski A.A.,Poutanen J.,Miko l ajewska J.,Gierli´n ski M.,Ebisawa K.,&Johnson W.N.,1998,MNRAS,301,435.26.Frontera F.et al.,2001a,ApJ,546,1027.27.Frontera F.et al.,2001b,ApJ,561,1006.28.Zdziarski A.A.,Gilfanov M.,Lubi´n ski P.,&Revnivtsev M.,2002,in preparation.29.Zdziarski A.A.,Lubi´n ski P.,&Smith D.A.,1999,MNRAS,303,L11.30.Gilfanov M.,Churazov E.,&Revnivtsev M.,2000,in Zhao G.,Wang J.J.,Qiu H.M.,Boerner G.,eds,SGSC Conference Series Vol.1,5th Sino-German Workshop on Astrophysics.China Science&Technology Press,Beijing,114(astro-ph/0002415).31.Georganopoulos M.,Aharonian F.A.,&Kirk J.G.,2002,A&A,388,L25.32.Stern B.E.,Beloborodov A.M.,&Poutanen J.,2001,ApJ,555,829.33.Golenetskii S.,et al.,2002,IAUC7840.34.Shrader C.,&Titarchuk L.,1998,ApJ,499,L31.35.Borozdin K.,Revnivtsev M.,Trudolyubov S.,Shrader C.,&Titarchuk L.,1999,ApJ,517,367.urent P.,&Titarchuk L.,1999,ApJ,511,289.。

2023名校版高考英语阅读理解精读附答案gh

2023名校版高考英语阅读理解精读附答案Austrian company Tec-Innovation recently unveiled smart shoes that use ultrasonic sensors (声波传感器) to help people suffering from blindness or vision impairment to detect obstacles up to four metres away.Known as InnoMake, the smart shoe aims to become an alternative to the decades-old walking stick that millions of people around the world depend on to get around as safely as possible. The currently available model relies on sensors to detect obstacles and warns the wearer via vibration and an audible alarm sounded on a Bluetooth-linked smart phone. That sounds impressive enough, but the company is already working on a much more advanced version that includes cameras and artificial intelligence to not only detect obstacles but also their nature.“Not only is the warning that I am facing an obstacle relevant, but also the information about what kind of obstacle I am facing. Because it makes a big difference whether it’s a wall, a car or a staircase,”Markus Raffer, one of the founders of Tec-Innovation,told TechXplore. “Ultrasonic sensors on the toe of the shoe detect obstacles up to four metres away. The wearer is then warned by vibration and/or audio signals. This works very well and is already a great help to me personally.”The current version of the InnoMake shoe is already available for purchase on the Tec-Innovation website, for 3,200 per pair. The advanced system is integrated in the front of the shoes, in a waterproof and dustproof case. It is powered by a heavy-duty battery that can last for up to one week, depending on use. The battery can be charged in just three hours, using a USB cable.The next step for Tec-Innovation is to use the data collected by its system to create a kind of street view navigation map for visually impaired people. “As it currently stands, only the wearer benefits in each case from the data the shoe collects as he or she walks. It would be much more sustainable if this data could also be made available to other people as a navigation aid,”computer scientist Friedrich Fraundorfer explained.12．What does the underlined word “unveiled”in paragraph 1 probably mean?A．Purchased.B．Launched.C．Evaluated.D．Promoted.13．What is required when a person uses InnoMake? A．An ultrasonic sensor.B．A walking stick.C．A smart phone.D．A new camera.14．What can we know about Markus Raffer? A．He himself is visually impaired.B．He is faced with a lot of obstacles.C．He is the founder of TechXplore.D．He has different opinions from others. 15．Where does the text probably appear?A．In a lab research.B．In a book review.C．In a health magazine.D．In a science website.12．B 13．C 14．A 15．DIn habitats across the planet, animals periodically drop everything to walk, fly or swim to a new place. Wildlife such as whales and geese learn migration paths by following their parents. Others, including small songbirds, gain the distance and direction of their migration within their genetic code. And some animals use a combination of genetics and culture to guide their migration.Another group of migrators does not quite fit either model, and researchers have only recently started to figure out how they find their way. Take the Cory’s shearwater, an oceangoing sea bird that migrates over the Atlantic every year. The young do not migrate with their parents, so culture cannot explain their journeys. And the exact paths vary wildly from individual to individual, making genetics equally unlikely.Cory’s shearwaters are long-lived, rarely producing young successfully before age nine. This leaves an opening for learning and practice to develop their migration patterns. Researchers call this the “exploration-refinement”, and until now it has been hypothetical (假设的) because of difficulties in tracking migratory animals’movements.But a team of researchers has done that by attaching small geolocators to more than 150 of the birds aged four to nine. They found that younger birds traveled longer distances, for longer periods, and had more diverse paths than older birds. “We finally have evidence of the ‘exploration-refinement’for migratory birds,”says Letizia Campioni, who led the study. Younger Cory’s shearwaters are able to fly just as fast as the adults—but they do not, suggesting that the young do more exploring, which gradually fades as they mature and settle into a preferred course.Although it may seem less efficient than other strategies, “exploration refinement could be beneficial to birds and other organisms in a rapidly changing world due to unpredictable man-made changes,”says Barbara Frei. “It might be safer to repeat a behavior that was recently successful than to rely onpatterns that were perfected long ago but might no longer be safe.”32. What is the first paragraph mainly about? .A. It describes animals’habitats.B. It talks about migration models.C. It compares different species.D. It introduces a tracking technology.33. What does the underlined word “this”in paragraph 3 refer to?A. The opening for learning and practice.B. The unique living habit of Cory’s shearwaters.C. The way Cory’s shearwaters form their migration patterns.D. The process scientists track Cory’s shearwaters’movements.34. What does Letizia’s study find about the younger Cory’s shearwaters?A. They travel as much as adult birds.B. They move in a predictable manner.C. They lower the speed for exploration.D. They look for a course with their parents.35. What can we conclude from the last paragraph?A. Man-made changes make migration easier.B. Animals make a safer journey via a fixed track.C. Course exploration contributes to birds’adaptability.D. A combination of strategies assures migration success. 32-35BCCC。

Alzheimer’s Disease Peptide Epitope Vaccine Reduces Insoluble But Not soluble-Oligomeric

Neurobiology of DiseaseAlzheimer’s Disease Peptide Epitope Vaccine Reduces Insoluble But Not Soluble/Oligomeric A␤Species in Amyloid Precursor Protein Transgenic MiceIrina Petrushina,1*Anahit Ghochikyan,3*Mikayel Mktrichyan,3Gregory Mamikonyan,3Nina Movsesyan,1Hayk Davtyan,3Archita Patel,1Elizabeth Head,1,2David H.Cribbs,1,2‡and Michael G.Agadjanyan1,3‡1The Institute for Brain Aging and Dementia and2Department of Neurology,University of California,Irvine,Irvine,California92697-4540,and3The Institute for Molecular Medicine,Department of Immunology,Huntington Beach,California92647Active vaccination of elderly Alzheimer’s disease(AD)patients with fibrillar amyloid-␤peptide(A␤42),even in the presence of a potent Th1adjuvant,induced generally low titers of antibodies in a small fraction(ϳ20%responders)of those that received the AN-1792 vaccine.To improve the immunogenicity and reduce the likelihood of inducing adverse autoreactive T-cells specific for A␤42,we previously tested in wild-type mice an alternative approach for active immunization:an epitope vaccine that selectively initiate B cell responses toward an immunogenic self-epitope of A␤in the absence of anti-A␤T cell responses.Here,we describe a second generation epitope vaccine composed of two copies of A␤1–11fused with the promiscuous nonself T cell epitope,PADRE(pan human leukocyte antigen DR-binding peptide)that completely eliminates the autoreactive T cell responses and induces humoral immune responses in amyloid precursor protein transgenic2576mice with pre-existing AD-like pathology.Based on the titers of anti-A␤1–11antibody exper-imental mice were divided into low,moderate and high responders,and for the first time we report a positive correlation between the concentration of anti-A␤1–11antibody and a reduction of insoluble,cerebral A␤plaques.The reduction of insoluble A␤deposition was not associated with adverse events,such as CNS T cell or macrophage infiltration or microhemorrhages.Surprisingly,vaccination did not alter the levels of soluble A␤.Alternatively,early protective immunization before substantial neuropathology,neuronal loss and cogni-tive deficits have become firmly established may be more beneficial and safer for potential patients,especially if they can be identified in a preclinical stage by the development of antecedent biomarkers of AD.Key words:immunotherapy;Alzheimer’s disease;epitope vaccine;antibody;PADRE;␤-amyloidIntroductionThe age-related accumulation of amyloid-␤(A␤)in the CNS has been hypothesized to play a central role in a cascade of events that eventually induces neuronal loss in affected brain regions in Alz-heimer’s disease(AD)(Selkoe,1991,1994;Hardy and Higgins, 1992;Price and Sisodia,1994;Esler and Wolfe,2001;Hardy and Selkoe,2002).Previously,major support for the amyloid cascade hypothesis emerged from A␤-immunotherapy studies demon-strated that anti-A␤antibodies were capable of reducing AD-like pathology(Schenk et al.,1999)and improving behavior in amy-loid precursor protein(APP)transgenic(Tg)mice(Chen et al., 2000;Janus et al.,2000;Morgan et al.,2000).First,immunother-apy clinical trial in AD patients using the AN-1792vaccine con-taining B and T cell“self epitopes”of A␤42was halted during Phase IIa,whenϳ6%of the participants developed aseptic me-ningoencephalitis(Schenk,2002;Weiner and Selkoe,2002;Hock et al.,2003;Nicoll et al.,2003;Orgogozo et al.,2003;Ferrer et al., 2004;Bayer et al.,2005;Fox et al.,2005;Gilman et al.,2005; Masliah et al.,2005;Patton et al.,2006).Importantly,only vacci-nated participants(nϭ18)developed meningoencephalitis, whereas none of the control patients(nϭ72)injected with pla-cebo developed adverse events(Orgogozo et al.,2003).Data from these trials suggest that the aseptic meningoencephalitis may have been caused by a T cell-mediated autoimmune response(Nicoll et al.,2003;Ferrer et al.,2004),and that anti-A␤antibodies were not responsible for the observed adverse effects after active vac-cination.In fact,low/moderate titers of anti-A␤antibodies gen-erated in a small subset of immunized patients(19.7%)were capable of reducing parenchymal amyloid pathology(Nicoll et al.,2003,2006;Ferrer et al.,2004;Masliah et al.,2005;Patton et al.,2006;Boche et al.,2007;Nitsch and Hock,2007)and dimin-ishing progressive cognitive decline associated with the disease (Hock et al.,2003;Gilman et al.,2005).However,ϳ80%of the immunized subjects failed to develop anti-A␤antibody titers (“nonresponders”),indicating that the A␤self-antigen in theReceived July13,2007;revised Oct.1,2007;accepted Oct.7,2007.This work was supported by National Institutes of Health Grants AG20241and NS50895(D.H.C.)and Alzheimer’sAssociation Grant IIRG-03-6279(M.G.A.).Additional support for mice and the production of peptides was providedby University of California,Irvive Alzheimer’s Disease Research Center Grant P50AG16573.Dr.Nina Movsesyan wassupported by National Institute on Aging training Grant AG00096.We thank Adrine Karapetyan for technical helpand valuable comments.*I.P.and A.G.contributed equally to this work.‡D.H.C.and M.G.A.contributed equally to this work as senior authors.Correspondence should be addressed to Dr.Michael G.Agadjanyan,The Institute for Molecular Medicine,16371Gothard Street,H,Huntington Beach,CA92647-3652.E-mail:magadjanyan@.DOI:10.1523/JNEUROSCI.3201-07.2007Copyright©2007Society for Neuroscience0270-6474/07/2712721-11$15.00/0The Journal of Neuroscience,November14,2007•27(46):12721–12731•12721AN-1792vaccine was not a strong immunogen,thus suggesting that alternative immunotherapeutic strategies should be pursued.Based on the results generated in mouse models of AD(Bard et al.,2000;DeMattos et al.,2001;Dodart et al.,2002),a new clinical trial,AAB-001(Elan and Wyeth Pharmaceuticals,http:// /investorrelations/events/elanwyethsymposium_adpd. asp),has been initiated by using passive transfer of a humanized monoclonal anti-A␤antibody(bapineuzumab)in an attempt to avoid the problems associated with active immunization of el-derly AD patients.However,the design of this new trial is associ-ated with additional challenges such as multiple injections of high concentrations of anti-A␤antibody every13weeks,the high cost of this monoclonal humanized antibody as well as possible side effects of passive vaccination,including microhemorrhages ob-served in passively immunized very old APP Tg mice(Pfeifer et al.,2002;Wilcock et al.,2004;Racke et al.,2005).This suggests that development of safe active immunotherapeutic strategies may still be desirable.Previously,we engineered and tested a first generation epitope vaccine in wild-type mice(Agadjanyan et al.,2005),and here we report the development and testing the safety and efficacy of therapeutic vaccination of APP Tg2576mice with pre-existing AD-like pathology with a second generation epitope vaccine composed of two copies of the B cell epitope,A␤1–11in tandem with pan human leukocyte antigen DR-binding peptide(PA-DRE),a synthetic,foreign promiscuous T cell epitope[pre-existing AD-like pathology implies the accumulation of soluble oligomeric forms of amyloid-beta peptide leading to the impair-ment of cognitive functions inՆ6-month-old APP Tg2576mice (Lesne et al.,2006)].Materials and MethodsMice,epitope vaccine,peptide immunogens,and experimental protocol. Aged(ϳ9.4months old)female APP Tg2576mice were bred and pro-vided by the animal facility associated with the University of California at Irvine(UCI)Alzheimer’s Disease Research Center.All animals were housed in a temperature and light-cycle controlled facility,and their care was under the guidelines of the National Institutes of Health and an approved Institutional Animal Care and Use Committee protocol at University of California at Irvine.To engineer an epitope AD vaccine,we synthesized the N terminus of an immunodominant B cell epitope of A␤1–11(McLaurin et al.,2002; Bard et al.,2003;Cribbs et al.,2003)in tandem with a promiscuous foreign T cell epitope,so called pan-DR epitope,PADRE(Alexander et al.,1994).The peptide2A␤1–11-PADRE was synthesized as a multiple antigenic peptide(MAP),containing a core matrix of4branching lysines (Tam,1988;Chai et al.,1992)to generate2A␤1–11-PADRE-MAP(In-vitrogen,Carlsbad,CA).A␤42peptide was synthesized at the Peptide Core Facility at the Institute for Brain Aging and Dementia at UCI by solid-phase Fmoc amino acid substitution and purified by reverse-phase high-pressure liquid chromatography.Mice were immunized with2A␤1–11-PADRE-MAP or fA␤42as de-scribed previously(Cribbs et al.,2003;Petrushina et al.,2003;Agadjan-yan et al.,2005).Briefly,2A␤1–11-PADRE-MAP(500␮g/ml)or the fibril-lar(Schenk et al.,1999;Cribbs et al.,2003)A␤42peptide(500␮g/ml) were mixed with Quil A,a Th1-type conventional adjuvant,and mice were injected with50␮g of antigen subcutaneously.Experimental mice at age9.4Ϯ0.9months old were immunized with2A␤1–11-PADRE-MAP(nϭ21)or fA␤42(nϭ12),whereas the control group of APP Tg 2576mice(nϭ11)was injected with an adjuvant only.All mice were boosted at monthly intervals.Cellular immune responses were analyzed in five mice from each group killed at9d after the fourth immunization. We continued to boost the remaining mice at monthly intervals and sera was collected at8–10d after the third,fourth,sixth and10th immuniza-tions and used for detection of anti-A␤antibodies.At the end of the study,after10vaccinations when animals were19.4Ϯ0.9months old, neuropathological changes were compared across groups in response to treatment.In these animals,cellular immune responses also were analyzed.T cell proliferation.The analysis of T cell proliferation was performed in splenocyte cultures from individual animals,as described previously (Cribbs et al.,2003;Agadjanyan et al.,2005).In addition,CD4ϩT cell proliferation was assessed using FACS assay according to the manufac-turer’s instructions(BD Biosciences,San Jose,CA).Briefly,to detect antigen-specific proliferation of CD4ϩT cells,we stained splenocyte cul-tures by1␮M succinimidyl ester of carboxyfluorescein diacetate(CFSE; Invitrogen)for10min at37°C.After washing,the cells were incubated for3d in culture media alone or with PADRE(5␮M).After incubation, the cultures were stained with phycoerythrin(PE)-labeled rat anti-mouse CD4monoclonal antibodies(BD Biosciences).Because dead cells might fluoresce nonspecifically,these cells were excluded from the assay using a nucleic acid dye(7-amino actinomycin D from BD PharMingen, San Diego,CA),and proliferation of viable cells was analyzed by FACS-can flow cytometer(BD Biosciences)as described by the manufacturer. CD4ϩpopulation was separately analyzed using CellQuest software(BD Biosciences).Production of cytokines by immune splenocytes.The same splenocytes used to assess T cell proliferation were used for detection of Th1(IFN␥) or Th2(IL4)lymphokines by ELISPOT(BD PharMingen)as described previously(Cribbs et al.,2003;Agadjanyan et al.,2005).In addition,the FACS method was used for detection of specific cytokines by CD4ϩT cells(Pala et al.,2000).Briefly,the cultures of splenocytes from experi-mental and control animals were restimulated for3–4d with PADRE peptide(5␮M),and then for4–6h with PMA(phorbol12-myristate 12-acetate)and ionophore(ionomycin)(both from Sigma,St.Louis, MO).In addition,we used Brefeldin A(BD Biosciences)to block cyto-kine secretion,which increases intracellular accumulation.Surface stain-ing was performed using FITC-labeled anti-mouse CD4monoclonal an-tibodies(MoAb;BD PharMingen).Cells were washed,fixed, permeabilized,and CD4ϩT cell subset producing IL-4or IFN␥was de-tected using the appropriate PE-labeled anti-mouse cytokine antibodies (BD PharMingen).Detection of anti-A␤antibodies by ELISA.Total anti-A␤42antibodies were detected as described previously(Cribbs et al.,2003;Petrushina et al.,2003)with small modifications:to develop the color reaction we used the3,3Ј,5,5Јtetramethylbenzidine(TMB)peroxidase substrate(Pierce, Rockford,IL),and plates were analyzed spectrophotometrically at450 nm.The standard curve for determination of anti-A␤antibody concen-trations in the sera was based on different known concentrations of monoclonal antibody20.1kindly provided by Dr.Van Nostrand(Stony Brook University,Stony Brook,NY).The concentrations of antibody were recorded in micrograms per milliliter.To determine the specific isotypes,pooled sera from mice were diluted1:2500and tested in dupli-cate.As we reported previously,mice of H2bxs immune haplotype(APP Tg2576)do not express IgG2a,producing IgG2c anti-A␤antibodies instead(Petrushina et al.,2003).Therefore,in our experiments we used anti-IgG2a b-specific antibodies(BD PharMingen)along with anti-IgG1-,IgG2b-and IgM-specific antibodies(Zymed,San Francisco,CA). Detection of A␤plaques in human brain tissues.Sera from immunized mice were also screened for the ability to bind to A␤plaques in the human brain as we described previously,using immunohistochemistry (Ghochikyan et al.,2003;Agadjanyan et al.,2005).A digital camera (Olympus,Tokyo,Japan)was used to capture images of the plaques at 20ϫmagnification.The binding of antisera(dilution1:1000)to the ␤-amyloid plaques was blocked by preabsorption of the sera with5␮M A␤1–15peptide(1h,37°C).Immunohistochemistry.To analyze the effect of active immunization with the epitope vaccine on neuropathological changes in APP Tg2576 mice(19.4Ϯ0.9months old),the brains were processed for immuno-histochemistry and histochemistry by previously published methods (Ghochikyan et al.,2003;Agadjanyan et al.,2005).Animals were killed under deep Nembutal sodium solution(150mg/kg,i.p.)anesthesia.To ensure proper fixation and immunostaining of brain tissues,mice were exsanguinated by transcardial perfusion with normal saline.Then brains12722•J.Neurosci.,November14,2007•27(46):12721–12731Petrushina et al.•Testing the Epitope Vaccine in APP Tg2576Micewere removed and bisected in midsagittal plane.The right hemispherewas snap frozen for biochemical analysis,whereas the left hemispherewas fixed in4%paraformaldehyde for immunohistochemical analysis.Forty-micrometer-thick free-floating coronal sections of fixed hemi-brains were collected using a vibratome.To assess the extent of neuropa-thology and neuroinflammation that occurs in the brains of mice,thefollowing primary antibodies were used.A␤deposits were detected with anti-A␤42(dilution,1:2000;Invitrogen)and anti-A␤40(1:10000;Invitro-gen).Activated microglia were detected with the anti-I-A/I-E[marker ofmajor histocompatibility complex(MHC)II alloantigens;1:200;BDPharMingen]and anti-CD45(1:300;Serotec,Raleigh,NC)antibodies.Astrocytes were labeled with anti-glial fibrillary acidic protein(GFAP;1:3000)antibodies(Eng et al.,2000).Infiltration of T cells and macro-phages were analyzed using anti-CD3-␧(1:50;Santa Cruz Biotechnol-ogy,Santa Cruz,CA),anti-CD4,anti-CD8(1:250;Novocastra Laborato-ries,Newcastle,UK),and anti-F4/80(1:50;Serotec)antibodies,respectively.The tissues from all animals within a given experimentalgroup were processed in parallel.Sections to be immunostained withanti-A␤antibodies were pretreated in90%formic acid for4min to enhance A␤staining(Kitamoto et al.,1987).Sections for the staining with anti-CD45and anti-I-A/I-E(anti-MHC II)were pretreated withproteinase K(0.03mg/ml)for5–7min at room temperature.Hydrogenperoxide-quenched and blocked sections were incubated with primaryantibody overnight at4°C.Sections were then washed and incubatedwith appropriate biotinylated secondary antibodies(1h at room temper-ature).After multiple washes,the tissues were incubated in ABC for1h,and color development was performed using DAB(3,3Ј-diaminobenzidine)substrate kit(Vector Laboratories,Burlingame,CA).Sections were mounted on Vectabond-coated slides(Vector Laborato-ries),dehydrated,and covered using DPX(BDH Laboratory Supplies,Poole,UK).Fibrillar A␤deposits were visualized using Thioflavin S (ThS)as described by(Schmidt et al.,1995).Briefly,mouse brain sectionswere washed with Tris buffer and stained for10min with a solution of0.5%ThS in50%ethanol.Finally,sections were washed in50%ethanoland Tris buffer,then dried and covered using Vectashield(VectorLaboratories).Quantitative image analysis.NIH imaging was used to analyze the areaoccupied by␤-amyloid and glial reactivity as described previously(Head et al.,2001).Immunostaining was captured using a Sony(Tokyo,Japan)high-resolution CCD video camera(XC-77)and NIH image1.59b5soft-ware.For every animal,12images(525ϫ410␮m each)of the frontal parietal region in the cortex at approximately the same plane(0.74to Ϫ2.9mm with respect to bregma)of two adjacent sections were captured with a20ϫor40ϫobjective.The samples included six images from thesuperficial layer and the remaining six from the deep layer.NIH imagingwas used to analyze the area occupied by␤-amyloid(A␤load)relative to the background,and expressed as the percentage of area occupied.The threshold for detection of immunoreactivity was established and then held constant throughout the image analysis.ThS-positive plaques were counted by visual inspection of cortical region of all stained sections although blind with respect to treatment condition;a mean semiquanti-tative score was independently determined for each slide by two observers.Prussian blue staining for microhemorrhage.Staining for hemosiderindeposits was performed on duplicate adjacent coronal sections of themice brains containing similar regions located at approximatelyϪ1.5bregma point,50␮m thick,collected from immunized and naive,age-matched APP Tg2576mice.The sections were stained with Prussian blue working solution(equal parts of freshly made5%potassium ferrocianide and5%hydrochloric acid)for30min at room temperature,washed in deionized water,and counterstained with Nuclear fast red.Possible hem-orrhage events in the form of the number of Prussian blue-positive pro-files were counted in the brains of each mouse on all sections by two independent observers,and the average number of hemosiderin deposits was calculated per each brain hemisphere.Biochemical analysis.Biochemical analysis of the brain tissue was pro-cessed as described previously(Kawarabayashi et al.,2001),except thatcortices of right hemispheres of brains were used.Briefly,frozen corticeswere thawed,minced and then homogenized in50m M Tris-HCl buffer containing2%SDS,pH8.0,and a mixture of protease inhibitors(MP Biomedicals,Solon,OH).Homogenates were centrifuged(100,000ϫg, 1h,4°C)and supernatants were stored atϪ70°C for additional analysis of soluble␤-amyloid.Seventy percent formic acid was added to the pel-lets for extraction of SDS-insoluble␤-amyloid.After sonication samples were centrifuged(100,000ϫg,1h,4°C)and supernatants were stored for analysis of insoluble␤-amyloid.After neutralization of formic acid with 1.0M Tris-base/0.5M NaH2P04,concentrations of insoluble and soluble A␤40and A␤42were analyzed using␤-amyloid ELISA kits(Invitrogen) according to the manufacturer’s recommendations.Plates were analyzed spectrophotometrically at450nm via a microplate reader,and the con-centrations of A␤40and A␤42were calculated using standard curves for A␤40and A␤42peptide by comparing the sample’s absorbance with the absorbance of known concentrations of a ing the wet weight of cortex region in the original homogenate,the final values of A␤were expressed as micrograms per gram wet weight of cortex.Dot blot assay and combination of IP and WB.Soluble fractions from cortical homogenates of experimental and control mice used in ELISA were also used for dot blot assay and for both immunoprecipitation(IP) and Western blot(WB).Total protein concentration in the homogenates was determined using bicinchoninic acid assay(Pierce)and adjusted to4 mg/ml with PBS.Dot blot.Two microliters of sequential dilutions of homogenates were applied to nitrocellulose membrane(GE Healthcare,Piscataway,NJ), air-dried,and blocked with5%fat-free dry milk in TBST(10m M Tris-HCl,pH8.0,150m M NaCl,0.05%Tween20).Oligomers were detected by using HRP-conjugated A11polyclonal antibody(kindly provided by Dr.C.Glabe,University of California,Irvine,Irvine,CA).Blots were developed with ECL detection system(Santa Cruz Biotechnology).Au-toradiograms were scanned,and densitometry of A␤oligomer spots was performed with NIH Image J software,version1.36b.The relative optical density was calculated and presented as average valueϮSD for each group.IP and WB.Aliquots of homogenates were pooled into four groups (based on low,moderate,high anti-A␤antibody responders and control nonimmunized mice,200␮g of total protein in each pooled aliquot), diluted to500␮l with PBS and incubated(overnight at4°C)with anti-A␤20.1monoclonal antibody immobilized on protein G-sepharose.The beads were washed three times in PBS,and proteins were eluted in20␮l of SDS-PAGE loading buffer by boiling.Samples were subjected to elec-trophoresis on12.5%SDS-Tris polyacrylamide gel and proteins were electrotransferred to polyvinylidene difluoride membrane(GE Health-care).The membrane was boiled for2min and blocked with5%fat-free dry milk followed by detection of A␤oligomers using anti-A␤biotinyl-ated20.1monoclonal antibody.Three experiments with the same ho-mogenates were performed and Western blots were scanned and con-verted into digital files.Densitometry of A␤oligomer bands were performed using NIH Image J software,version1.36b and data(aver-ageϮSD)were presented from three experiments.Statistical analysis.All statistical parameters(mean,SD,significant difference,etc.)used in experiments were calculated using Prism3.03 software(GraphPad Software,San Diego,CA).Statistically significant differences were examined using an ANOVA and post hoc comparisons were done using Tukey’s test(pϽ0.05was considered as statistically different).ResultsThe second generation epitope vaccine stimulatesCD4؉IFN␥؉T cells specific to PADRE without activation of autoreactive anti-A␤T helper cellsTo circumvent the side effects of the AN-1792vaccine against AD,we engineered a vaccine in which a foreign T helper cell epitope was incorporated with two copies of the B cell epitope of A␤42.APP Tg2576mice vaccinated with2A␤1–11-PADRE-MAP induced T cell responses directed against the foreign antigenic determinant,PADRE,but not against self A␤antigen.More spe-cifically,splenocytes isolated from vaccinated animals prolifer-ated after re-stimulation with PADRE,but not A␤40(Fig.1A).InPetrushina et al.•Testing the Epitope Vaccine in APP Tg2576Mice J.Neurosci.,November14,2007•27(46):12721–12731•12723contrast,control APP Tg2576mice vacci-nated with fibrillar A␤42antigen(fA␤42) that has self B and T cell antigenic deter-minants induced only autoreactive T cells activated after restimulation with A␤40 (Fig.1A).Direct measurement of activation of PADRE-specific CD4ϩT helper cells in vaccinated APP Tg2576mice by a FACS assay confirmed these results.CD4ϩT cells from mice vaccinated with the pep-tide epitope vaccine induced strong prolif-eration of this subset of T cells after re-stimulation with nonself PADRE peptide, but not A␤40(Fig.1B).In contrast,vacci-nation with fA␤42formulated in QuilA ad-juvant induced proliferation of CD4ϩT cells activated after re-stimulation with self-antigen A␤40,but not with nonself T cell epitope PADRE.Of note,CD4ϩT cells from mice injected with adjuvant did not proliferate after restimulation either with PADRE or A␤40peptides(Fig.1B).To further investigate T cell responses to vaccination,we analyzed Th1(IFN␥) and Th2(IL-4)cytokine production by splenocytes and CD4ϩT cells from im-munized and control APP Tg2576miceusing ELISPOT and FACS assays,respec-tively(Fig.1C,D).In these experiments,splenocytes from mice vaccinated with epitope vaccine were restimulated with PADRE, whereas splenocytes isolated from animals immunized with fA␤42were restimulated with A␤40.Groups of APP Tg2576mice injected with the epitope vaccine induced a strong IFN␥(Th1) response based on the number of splenocytes producing this lym-phokine,whereas mice immunized with fA␤42had low re-sponses.Because we used a Th1adjuvant in both the epitope and fA␤42vaccinations,it was not surprising that both groups of mice generated less IL-4(Th2)than IFN␥(Th1),whereas splenocytes from naive mice did not generate either IL4or IFN␥cytokines (Fig.1C).We confirmed these results by measuring the produc-tion of IL-4or IFN␥cytokines in CD4ϩT helper cells.We found that the number of PADRE-specific CD4ϩIFN␥ϩT helper cells in mice immunized with the epitope vaccine was higher than the number of anti-A␤CD4ϩIFN␥ϩT cells in mice immunized with fA␤42(Fig.1D).The same was true for IL-4-producing anti-PADRE and anti-A␤CD4ϩT cells,although both groups had significantly lower number of CD4ϩT cells producing IL-4than IFN␥(Fig.1D).Thus,CD4ϩT cells and splenocytes isolated from both vaccinated groups predominantly produced a Th1-type cytokine,IFN␥,consistent with antigens being formulated in a Th1-type adjuvant,Quil A.Cellular immune responses ana-lyzed after4(Fig.1)and10(data not shown)immunizations showed the same specificity and profile.Collectively,the analyses of T cells demonstrated that the epitope vaccine did not activate autoreactive T cells,but stimulated nonself PADRE-specific CD4ϩIFN␥ϩT lymphocytes.Anti-PADRE-specific CD4؉IFN␥؉T lymphocytes help B cells to produce therapeutically potent anti-A␤1–11specific antibody in vaccinated APP Tg2576To determine the ability of activated PADRE-specific T cells to stimulate anti-A␤B cells,we measured antibody concentrations in the sera pooled from each group of animals after three,four, six,and10immunizations.After three injections of the epitope vaccine the concentrations of anti-A␤antibodies in the sera were higher than that in mice immunized with fA␤42.However,after the sixth immunization this difference in anti-A␤antibody titers steadily diminished,becoming equal after the last two boosts in both groups(Fig.2A).Of note,mice immunized with the Quil A adjuvant alone did not induce anti-A␤antibodies(data not shown).As mentioned above,these data were generated with sera pooled from each of the group;however,in individual animals we found significant variability in anti-A␤antibody responses(Fig. 2B).Concentrations of anti-A␤1–11antibodies after10immuni-zations were high in four mice immunized with the epitope vac-cine(176.8Ϯ163.56␮g/ml),whereas an additional eight and four vaccinated animals induced moderate(22.2Ϯ14.16␮g/ml) and low levels(1.2Ϯ1.5␮g/ml)of anti-A␤1–11antibodies,re-spectively(Fig.2C–E).This individual variability in humoral im-mune responses was also detected in the group of mice immu-nized with fA␤42antigen(Fig.2C–E):four mice generated high (82.65Ϯ22.68␮g/ml),one mouse had moderate(23.3␮g/ml), and two animals had low concentrations(0.9Ϯ0.7␮g/ml)of anti-A␤42antibodies.Thus,the epitope vaccine was at least as effective as fA␤42in induction of antibodies after10immuniza-tions,but was significantly more effective at initiating the anti-body immune responses(Fig.2A).To characterize the types of humoral immune responses from each vaccination group,we measured the production of IgG1, IgG2a b,IgG2b,and IgM anti-A␤antibodies in the sera collected from individual animals after a total of10injections of the epitope vaccine or fA␤42.All mice vaccinated with the epitope vaccine generated comparable amounts of IgG1,IgG2a b,and as a result,the average of IgG1/IgG2a b ratio was close to1(Fig.2F). This ratio implied that the epitope vaccine formulated in Th1Figure1.The second generation peptide epitope vaccine induces T cell response specific to promiscuous and nonself epitope, PADRE.Splenocyteswereisolatedfromindividualmice(nϭ5)afterfourthimmunizationandrestimulated invitro withPADREorA␤40peptides.A,Proliferationofsplenocyteswasdetectedby3[H]thymidineincorporation.B,D,ProliferationofCD4ϩTcells(B)and production of cytokines by this T cell subset(D)were detected by flow cytometry in pooled splenocyte cultures.Production ofIFN␥and IL4cytokines by pooled immune splenocytes was detected by ELISPOT assay(C).The experiment was repeated after the10th immunization with similar results.***pϽ0.001.12724•J.Neurosci.,November14,2007•27(46):12721–12731Petrushina et al.•Testing the Epitope Vaccine in APP Tg2576Mice。

Review of laser welding monitoring

Review of laser welding monitoringD.Y.You1,2,X.D.Gao*1and S.Katayama2Laser welding,as a highly efficient processing technology,has been widely applied to manufacturing industry.This paper makes an overview on real time monitoring of laser welding. It begins with a detailed introduction to six typical sensors(photodiode,visual,spectrometer, acoustical sensor,pyrometer,plasma charge sensor)in laser welding detection.Then it makes a review on multi-sensor fusion technology in both laser welding monitoring and adaptive control. Last,subjects for future research concerning welding monitoring and control have been proposed.The paper concludes that the real-time monitoring of laser welding can provide a great amount of valid information about welding status to help effectively identify weld defects and realize adaptive control.Keywords:Laser welding,Monitoring,Adaptive control,Optics sensing,Multiple sensor fusion,Welded quality inspectionIntroductionLaser welding has been widely used in various industrial ﬁelds such as automobile manufacturing,shipbuilding and bridge construction due to its advantages in realising high production,automotive processing,and forming a high quality weld with small heat affected zones.1–3Since its high energy density ranges from100 to1000kW mm22,the interaction between the laser beam and the welding material is rather strong, especially in the deep penetration welding of a thick plate.4Therefore,the online monitoring and quality inspection of high power laser welding are essential for making high quality production.Researches on detec-tion during laser welding process have been carried out by quite a number of scholars as early as twenty years ago.However,experimentalﬁndings were not applied to industrial manufacturing widely at that time due to considerable sensor cost,low devices accuracy and poor detecting efﬁciency.That few enterprises used laser for product processing is considered another major factor that restricts the further development of laser process monitoring.As the price of laser device decreases,laser technology begins toﬁnd wide use in the industrial ﬁelds.During mass production,effective real time monitoring over welding process can help to reduce production cost and improve production quality. Laser welding mainly involves the interaction between the laser beam and the welding material.In welding process,the laser light generally travels by way of optical ﬁbre and lens.Accordingly,the real time monitoring of laser welding process mainly focuses on the information of optical radiation in the weld zone,and most of the sensors used in the researches are optical sensors.5–7The development of real time detection during laser welding process has taken a leap in the past ten years with the advancement in sensor technology and the introduction of artiﬁcial intelligence technology.This paper makes an overview on laser welding monitoring.It begins with a detailed introduction to the physical background of laser welding and the basic principles of various detecting methods available currently.Then it makes a review on the integration of advanced multi-sensor detecting and intelligent recognition technology.The future develop-ment prospect of laser welding detection has been envisioned.By introducing the effective application of advanced sensing technology to laser welding detection and reviewing the attempts to use artiﬁcial intelligence technology for welding status recognition,this paper aims at presenting the current development situation of laser welding monitoring and adaptive control,and proposing possible subjects for future research. Basic mechanism of laser welding monitoringPrinciples of laser weldingIn laser welding,the material is rapidly heated up to a certain temperature,at which the molten metal starts to vaporise at the position of laser beam focus and creates a keyhole in the centre of the molten pool.The keyhole will remain open as continuous wave laser welding takes place because of the evaporation pressure.As shown in Fig.1,during a keyhole mode of laser welding,a plume containing metallic vapour and plasma was generated and ejected out of the keyhole.It should be mentioned that the characterisations of plasma are different when it is induced by various laser.In the case of CO2laser welding,a plume is only formed by the emission of neutral metal atoms when the shielding gas is He.If the gas used is Ar or N2,gas plasma is formed under the nozzle in addition to the plume during CO2laser welding.On the contrary,a plume is in the state of weakly ionised plasma duringﬁbre laser welding1School of Electromechanical Engineering,Guangdong University of Technology,No.100West Waihuan Road,Higher Education Mega Center,Panyu District,Guangzhou510006,China2Joining and Welding Research Institute,Osaka University,11-1 Mihogaoka,Ibaraki,Osaka567-0047,Japan*Corresponding author,email gaoxd666@ß2014Institute of Materials,Minerals and MiningPublished by Maney on behalf of the Instituteprocess.Almost all the peak values of spectroscopic come from the emission of neutral metal atoms,while the emission from Ar gas is not detected.At the same time,plenty of spatters would be ejected because of the high evaporation pressure inside the keyhole.Generally, the electromagnetic radiation from the welding position can be divided into three types.8Theﬁrst type is the ultraviolet and visible light emission generated from the plume.The second type is the laser light emission from the beam reﬂection.The last one is the thermal radiation coming from molten pool surface.Basically,laser welding process monitoring will focus on the character-istics of the molten pool,keyhole,plume,spatters and the radiation signal generated from the welding posi-tion.9–14The most common defects that appear during the laser welding process are crack,porosity,incomplete penetration,undercut,underﬁll and spatters.15,16 Typical structure of monitoring system for laser weldingUnlike that of traditional welding technology,energy transmission during laser welding is mainly carried out by the laser beam,which travels through the opticalﬁbre and lens and is then shone on the surface of the material. Based on this particular way of energy transmission, various inspection tasks can be fulﬁlled by adjusting the interior light path structure of the devices(laser head).5,17–20This section focuses on the four representa-tive detecting structures used during laser welding and gives a brief introduction to the sensor type compatible with each of these structures.Coaxial optical radiation detectionThe beam splitter mirror installed inside the laser head can help to transmit optical radiation signals from the welding area to the sensor.Some of the welding status can be recognised by analysing the signal intensity of different spectral bands.Independent analysis of the features of different spectral bands is carried out by using different ﬁlter lens.The light that travels through theﬁlter is detected by the photodiode sensor,processed by the signal ampliﬁer,and then collected by the oscillo-scope.21,22Apart from the signal analysis of particular spectral bands,analysis of full spectral waveband during welding process can also be carried out by using the ser head and spectrum analyser are connected by the opticalﬁbre.Light intensity informa-tion produced within the welding area is reﬂected by the beam splitter,transmitted through the opticalﬁbre and ﬁnally analysed by the spectrometer.23,24Coaxial visual detectionCoaxial visual detection is usually carried out by using the beam splitter installed insider the laser head. Generally speaking,there are three kinds of techniques used for coaxial visual detection,which are visible detection,infrared visual detection and auxiliary light source visual detection.For the visual detection of visible light wavebands,a suitableﬁlter lens(350–750nm)should be installed.25Infrared visual detection is mainly carried out by thermal infrared camera.17 During the detection of the auxiliary light,it is preferred to use high frequency stroboscopic laser as light source, and its waveband is set between800and990nm.26 Auxiliary light is projected over the welding area through the beam splitter,one of whose ends is linked with camera.Opticalﬁlter compatible with the auxiliary light should be set up between the beam splitter and the camera in order to obtain clear images of the welding area.Paraxial sound and temperature detectionSound signals are considered an indicator of welding status to a certain extent.Since coaxial detection technique is exclusively applicable to the detection of optical signals,the detection of sound signals is carried out by way of paraxial detection.There are basically two types of paraxial sound signals sensors,including the contact type and the non-contact type.The contact type of sound signal detection generally refers to acoustic emission sensing,which mainly monitors the stress waves generated by high temperature and high pressure inside the equipments or the workpiece.The waveband range detected is usually less than200kHz.27The non-contact type of sound signal detection generally refers to audible sound sensing,which is also called airborne emission detection.It mainly monitors the pressure waves when plasma and metallic vapour occur.The waveband range detected is usually human audible range of20Hz–20kHz.28Another kind of sensor used for paraxial detection is pyrometer.It is noticeable that the non-contact type of temperature sensor is usually installed behind the laser head in order to measure the thermal distribution of a molten pool.Plasma charge detectionDuring welding process,especially with a CO2laser beam,electrical conductivity has been generated inside the laser induced plasma.Hence,the contact probe can be used to effectively measure charge intensity within the plasma area,and then identify the welding status.One end of the circuit is linked with the base material,while the other end is connected with the laser head(the contact area and focus lens should be electrically isolated).Alternatively,it can also be set up as a probe within the area where plasma is generated.29Both resistor and capacitance are connected to the return circuit,and signals are sent out in the form of voltage.30 Fundamental research of different sensors for laser welding monitoring The characteristics of six sensors with wide use are summarised in Table1,and they are detailed in the following sections respectively.1Schematic diagram of keyhole model laser weldingPhotodiode sensorThe advantages of photodiode sensors,such as simple structure and low cost,have enabled it toﬁnd wide use in industrial manufacturing.As shown in Fig.2a,the optical combiner making use of photodiode sensor and different opticalﬁlter systems can help to carry out independent detection on plasma radiation(P-sensor), laser reﬂection(R-sensor)and thermal emission(T-sensor).8Experimental results reveal that there are three types of optical radiation signals during laser welding as shown in Fig.2b.Theﬁrst type is ultraviolet and visible light wavebands(200–750nm).The second type is laser reﬂection waveband(ﬁbre laser1070nm,disc laser 1030nm).The third type is infrared radiation waveband (1100–1700nm).Particularly,welding defects detection and even adaptive control can be realised by specifying the correspondence between light intensity signals and welding status.During gas laser welding(CO2laser),the plumes contain the metallic vapour and a large amount of plasma.Consequently,when the detection is carried out by visible sensing photodiode sensor,it can be observeda arrangement of sensors corresponding to laser welding phenomena;b schematic of wavebands of three monitoringsensors2Photodiode sensors for monitoring electromagnetic radiation from laser welding8Table1Characteristic of sensors used for welding monitoring and inspectionSensor Detected object Samplingfrequency/kHzEquipmentcostDefect detectioncapability LimitationsPhotodiode UV-visemission Vapour plumeor plasma1–100Low IncompletepenetrationLow efficiency inidentifying slight defectReflection Reflective laserenergyUndercutIR emission Thermal radiation BlowoutsLack of fusionCamera UV-vis Plasma plumeand molten pool 0?5–5Low IncompletepenetrationUndercutBlowoutsHumpingWeld seamdeviationSpattersBurn throughUnderfillRequirement foradditional componentsetupIR Thermal distribution0?1–0?5High Low sampling speedand high priceDiode laser illumination Keyhole andmolten pool0?5–5Medium High computingdemandsSpectrometer Spectrum ofplasma plume 0?1–1Medium Undercut Accuracy dependingon the plume behaviour BlowoutsCracksSpattersMicrophone Acoustic emissionsfromvapour plumeor work piece 10–500Low IncompletepenetrationToo sensitive to thenoise of environment MisalignmentPyrometer Temperatureof moltenpool or vapourplume 1–50Medium IncompletepenetrationLimited capability ofweld defects inspectionBurn throughCharge sensor Plasma chargecurrent 1–100Low IncompletepenetrationLimited application insolid-state-laser weldingHumpingthat the signals carry information for both thermal radiation and plasma radiation.31It has been noted that in the case of solid state laser welding (ﬁbre laser and disk laser),the plumes generated during welding are mainly metallic vapour.Experimental results show that the ionisation degree of laser induced plume is only 0?02even when the laser power is 10kW and the beam diameter is 0?13mm.Therefore,when visible sensing photodiode sensor is used for detection,the signals mainly come from thermal radiation of the metallic vapour and molten pool surface.32,33Since the evaporation capacity of the metal depends on penetration depth and seam width,it is suggested to use the signals collected by the visible sensing photo-diode sensor to identify the variation of penetration depth and seam width.It has been observed that visible sensing photodiode sensor is rather sensitive to the plume radiation emission.Accordingly,researchers attempt to take the multiple sensor approach to make a more accurate detection on the spatial position of the plume.For instance,Brocka and his research team have devised a photodiode sensing system that can help to detect plume position.As shown in Fig.3,four photodiodes are set up at concentric positions to detect light intensity signals sent out from different positions.The correlation between spatial light intensity radiation and the composite signals is then speciﬁed and the direction in which metallic vapour ﬂows is deter-mined.10,20The research of Paleocrassas shows that the laser reﬂection tends to be stable in the unstable welding process caused by the low welding speed (1mm s 21).Unacceptable welded defects,such as porosity and crack,appear in the weld seam.15,16The large amount of consecutive laser reﬂection indicates poor energy absorption inside the keyhole.Besides,when the low frequency component (5–10Hz)of the Vis-photodiode signal oscillates increasingly violently,it suggests instability in CW welding and PW welding.34Zhang has made an tentative research on the signal detection during underwater Nd:YAG laser welding and has found that the detected signal,from both ultraviolet and infrared waveband,well reﬂects theshielding condition variations of the local dry cavity.35A lot of research has been carried out on thefrequency features of optical signals during welding inrecent years,which is expected to specify the correlationbetween signal frequency and the periodical changes ofthe molten pool (or keyhole).Once the correlation isspeciﬁed,the frequency features of the characteristicsignals when weld defects occur can be identiﬁed.36Schmidt and his research staff have pointed out that inthe case of a 3?6kW laser lap welding of zinc coatedsteel sheets,with the material thickness being 1?3–2?5mm and the welding speed being 4–6m min ,thefrequency of weld pool oscillations is within the range of300–500Hz,while that of the keyhole oscillations iswithin the range of 2000–2500Hz.37,38As shown inFig.4,external frequency missing is related to somewelded defects.Daniele Colombo has investigated thereal time monitoring of low power (1kW)optical ﬁbrelaser welding performed on Titanium alloy (2mm).39Ithas been concluded that the time domain features oflight intensity signals of both visible light waveband(400–1000nm)and infrared waveband (1150–1800nm)reﬂect welding defects (such as power decreases,shield-ing gas ﬂow rate decrease,lack of penetration).Also,thefrequency characteristics of the signals are generallya photodiode sensor attached to laser head;b total reﬂection sensor consists of ring aperture,acrylic glass cylinder and four photodiode pairs;c position measurement principle of sensor3Schematic of vapour plume position measurement 204Windowed FFT of optical emissions of modulated weld-ing process 37lower than2400Hz.Especially,strong keyholeﬂuctua-tions occur when the frequency of visible light signals is in the1600–2400Hz range.Similarﬁndings have been concluded by Schmidt and his research staff.A.Molino has investigated the frequency characteristic along the time axes by using time frequency analysis method.40As shown in Fig.5,the high frequency component(4?8–12kHz)of the optical radiation signals increases greatly when welding defects occur.This provides a reliable basis for accurately positioning welding defects. Detection of typical welded defect like incomplete penetration(0?5–2mm)and porosity(0?2–1mm)have been tested.15,16Researches carried out by Giuseppe D’Angelo and his research team prove that the time domain analytical approach based on Winer–Ville distribution is more effective than the traditional one when used for locating welding defects.41The researches carried out by Alexander F.H.Kaplan and his co-workers focus on the features of light intensity radiation signals during laser welding.42–44It has been found that there is a rather high correlation (0?79–0?93)between the visible light and infrared thermal radiation under both the stable and instable welding conditions,while hardly any correlation (20?04–0?08)can be detected between laser reﬂection and the other two types of signals.During the welding of Zn coated steel where instability occurs,however,there is a certain correlation(0?5)between laser reﬂection and infrared thermal radiation.22Besides,a great number of experiments have proved that laser reﬂection is very sensitive to the change in keyhole size.When the welding parameters remain constant,a larger quantity of laser beams will be reﬂected as the keyhole expands. Conversely,less laser beams will be reﬂected if the keyhole is narrowed.15,16,45Undercut and blowouts defects can be detected better by the photodiode sensing system.15,16,46The researches have also found that the occurrences of some weld defects(such as blowouts)sometimes are rapid events concealed by theﬂuctuations of the original signal like T-sensor or R-sensor.47,48 Having speciﬁed the correlation between light signals and welding status,researchers begin to use the signals as the basis for adaptive control during welding process. Manfred Geiger has proposed a feedback control system that uses visible light radiation(300–900nm)for references.It adjusts weld pool and keyhole oscillations mainly by varying laser power.Experimental results show that although this approach can help to effectively suppress unwanted collapse and avoid weld defects,it fails to conduct satisfactory control over weld pool oscillations.49Kawahito has devised two close loop control systems(based on YAG andﬁbre laser respec-tively)by using infrared thermal radiation(1100–1700nm)and laser reﬂection(YAG laser:1064nm/ﬁbre laser:1090nm).As shown in Fig.6,adaptive control is effective for the suppression of bead width expansion. Welding materials include stainless steel,aluminium alloy,titanium alloy and so on.The proposed systems have been proven to be effective for sound welding when applied to various kinds of welding such as butt weld-ing,overlap welding,continuous laser welding and spot welding.50–54Visual sensorVisual sensor is mainly employed in visible detection, infrared visual detection and auxiliary light detection. The efﬁciency of a visible detection system is highly dependent on theﬁlter lens.Kim and other researchers attach a scanner with visual detecting system to the laser head and make real time detection on the remote welding of galvanised sheet.The study shows that using 532nm band passﬁlter for steel welding can help to capture clear keyhole images and identify penetration. While for the welding of aluminium alloy,a660nm band passﬁlter is preferable.55Although visible visual sensing has such advantages as simple structure and low cost,the information that it provides for identifying5Defects detection in time frequency analysis40welding status is very limited,which only contains the rough geometrical parameters of the keyhole and molten pool.It should also be noted that the values of the keyhole geometrical parameters captured by visible light visual sensor are slightly larger than their actual ones. Years ago,thermal infrared imager was widely employed in the study on temperature distribution of molten pool surface and base material.However,several of its disadvantages,such as high cost(20000to50000 dollars),low resolution(3206240pixel)and low sampling speed(mostly at60frame/second),have greatly restricted its application to industrial manufac-turing.Currently,thermal infrared imager is mainly used for scientiﬁc research.17Auxiliary light source visual detecting is generally carried out by projecting high frequency stroboscopic laser light over the weld area.This approach can actively suppress disturbance from the plume and arc light in the weld area and help to obtain valid information of the molten pool,keyhole and even spatters.In recent years, it has been widely applied to dynamic detection and identiﬁcation during welding process.The light source adopted in this approach is mainly diode laser.The waveband is often set between800to1100nm in the near-infrared range.Some researchers may prefer green light as the lighting source and accordingly,the waveband is set between510and610nm.5The transmitting power is in the range of30–500W,though for a high power lighting system it can reach1000W. Laser impulse frequency is between50and50kHz. Previous experiments on auxiliary light source detecting were mainly conducted in the laboratory.Researchers used auxiliary light source to observe the changes during laser welding.Therefore,both the lighting system and visual detecting system are set up outside the weld area. With the development of laser head integrated system,FILT(Fraunhofer Institute for Laser Technology)has successfully integrated auxiliary light source and visual detecting system within the same laser head which is shown in Fig.7.56,18Seam tracking is very important in laser welding. Because small focus wandering off weld seam may result in lack of penetration or unacceptable welds,and largely reduce heating efﬁciency.Consequently,the seam tracking ability of a laser welding system is of primary concern in welding process.Several methods have been investigated for weld seam localisation based on visual sensing.For instance,seam tracking system LPF from Precitec,Welding Monitor from Prometec,and RoboFind from Servo Robot have been commercialised for several years.Also,the laser focus deviations from the desired path can be estimated by coaxially monitor-ing the optical signals emitted from the weld pool area. The most popular technique used for weld seam detection is based on the principle of optical triangula-tion.A structured light is projected on the work piece surface ahead of the laser focus and the reﬂected scattered light is imaged back onto a camera.57–59The controller extracts information from the image that can be used for either weld detection or seam tracking.For seam tracking based on the optical triangulation,the information of trajectory between laser focus and detected point cannot be received during the welding. Therefore a delay error resulted from forerun of the sensor occurs when there is a trajectory distortion.This delay error can be minimised if the distance between the laser focal point and the detected point is very short. Some research has been conducted for infrared tempera-ture measurement of hybrid laser TIG welding process.60 By using IR thermograph the temperatureﬁeld of hybrid welding process is measured and calibrated.Gao and his research team integrated near-infrared visual detectinga weld bead made without adaptive control(left),and laser power and monitored signals(right);b weld bead producedwith adaptive control(left),and laser power controlled and monitored signals(right)6Adaptive monitoring and control based on heat radiation and reﬂected light50system with intelligent image recognition to realise accurate welding seam tracking.61–64The devices that combine near-infrared ﬁlter system (960–990nm)with a CMOS camera can help to reduce costs as well as secure high resolution and high accuracy of the detection results.On one hand,since the surface temperature and image grey scale of the molten pool have a similar distributionpattern,information about the thermal gradient change at the front part of the molten pool is obtained as shown in Fig.8.It is then used as the basis for determining the deviation degree of the laser beam from weld seam centre.12On the other hand,both Kalman ﬁltering algorithm and Elman neural network are used to make error compensation for the detecting results,helping to enhance the stability and robustness of visual detecting.65The combination of visual sensing technology and image processing has provided new research subjects for welding detection.Y.Zhang and his research team have obtained clear molten pool images with the aid of stroboscopic laser.66The geometrical parameters of the molten pool are extracted by way of image processing and are used as reference for non-linear system identiﬁcation during welding process.67,68Bardin has used the temperature information captured by a thermal imaging system for reference and adjusted laser power to conduct effective control over weld penetration.69The proposed close loop control system also successfully carries out continuous full penetration welding on materials with different thicknesses and prevents partial penetration and burn-through.With this approached,desirable full penetration welding can also be realized even when the focal position keeps changing.70SpectrometerSpectral analysis has always been used for studying plume features during laser welding process.As shown in Fig.9,the optical emission generated from welding area is collected by a collimator and transported by an optical ﬁbre.The optical spectrum of plume is then analysed by the spectrometer.71In recent years,how-ever,with the reduction in cost and equipment size as well as the availability of more port (I/O)conﬁguration,spectrometer has been gradually employed for online monitoring and adaptive control.Based on the relative intensity of the line spectra obtained from the spectro-meter,as shown in Fig.10,the electron temperature of different elements can be calculated by means of the Boltzmann-plot,which is derived from the Boltzmann equation.33Findings of previous researches show that prior to the occurrence of conspicuous weld defects (such as under-cut and blowouts)during aluminium alloy welding,not7Schematic of monitoring system with two visual sensors (NIR and CMOS)and images 18a grey distribution of molten pool near-infrared image;b 3D view of molten pool image grey value gradient;c gradient feature of molten pool edge8Seam position located by the grey value gradient 12。

保健机器人在对抗疾病方面的英语作文

保健机器人在对抗疾病方面的英语作文The advancement of technology has brought about great changes in various fields, including healthcare. One of the latest innovations in healthcare technology is the development of healthcare robots. These robots have proven to be incredibly beneficial in combating diseases and improving overall patient care.Healthcare robots are designed to support medical professionals in various tasks such as patient monitoring, medication distribution, and assisting with surgeries. They are equipped with sensors and cameras that allow them to collect vital signs and other important data, which can then be analyzed by healthcare professionals. This enables doctors to make more accurate diagnoses and provide better treatment options for patients.One of the major advantages of healthcare robots is their ability to reduce human error. By automating tasks such as dispensing medication or monitoring patient vitals, robots can help to eliminate mistakes that may be made by human healthcare providers. This not only improves patient safety but also helps to reduce the workload of medical professionals, allowing them to focus on more critical aspects of patient care.Healthcare robots are also proving to be valuable in the fight against infectious diseases. During the COVID-19 pandemic, robots were used in hospitals to disinfect rooms and deliver supplies to patients, reducing the risk of healthcare workers being exposed to the virus. These robots can also be programmed to interact with patients, providing companionship and emotional support during times of isolation.Furthermore, healthcare robots have the potential to revolutionize the field of telemedicine. By allowing patients to connect with healthcare providers remotely, robots can help to improve access to medical care for those living in remote or underserved areas. This can be particularly beneficial for patients with chronic conditions who require regular monitoring and care.In conclusion, healthcare robots are a valuable tool in the fight against disease. Their ability to automate tasks, reduce human error, and provide support to patients and healthcare providers makes them an essential part of modern healthcare systems. As technology continues to advance, we can expect to see even more innovative uses for healthcare robots in the future.。

荧光蛋白外文文献附翻译

Whole-body imaging with ﬂuorescent proteinsRobert M Hoffman &Meng YangAntiCancer,Inc.,7917Ostrow Street,San Diego,California 92111,USA.Correspondence should be addressed to R.M.H.(all@).Published online 2November 2006;doi:10.1038/nprot.2006.223The intrinsic brightness of ﬂuorescent proteins has been taken advantage of to develop a technology of whole-body imaging of tumors and gene expression in mouse internal organs.Stable transformation with ﬂuorescent protein genes can be effected using retroviral vectors containing a selectable marker such as neomycin resistance.The cells that stably express ﬂuorescent proteins can then be transplanted into appropriate mouse models.For whole-body imaging,nude mice are very appropriate.If wild-type mice are used,then hair must be removed by shaving or depilation.The instruments used can range from a simple LED ﬂashlight and appropriate excitation and emission ﬁlters to sophisticated equipment such as the Olympus OV100with a wide range of magniﬁcation,enabling both macroimaging and microimaging.It is crucial that proper ﬁlters be used such that background autoﬂuorescence is minimal.Fluorescent protein–based imaging technology can be used for whole-body imaging of ﬂuorescent cells on essentially all organs.The timeline for these experiments varies from 2days to 2months.INTRODUCTIONThis protocol enables the user to perform whole-body imaging of ﬂuorescent protein–expressing cells in mouse internal organs (Figs.1,2)as well as other small animals.The technique has many applications,including visualizing cancer growth and metastasis,gene expression,infectious disease,stem cells,immunology,neuro-biology and numerous others.This protocol will focus on cancer and gene expression.A crucial point is the stable expression of ﬂuorescent proteins in the cells to be imaged.Such stable expression can be effected by appropriate vectors containing the ﬂuorescent protein gene and a selectable marker such as antibiotic resistance.A number of green ﬂuorescent proteins (GFP)and red ﬂuorescent proteins (RFP;Fig.3)are now available for in vivo imaging.A wide range of instrumentation can be used for ﬂuorescent protein–based imaging,ranging from an LED ﬂashlight and appropriate excitation and emission ﬁlters to highly speciﬁc instrumentation such as the Olympus OV100,a small animal imaging apparatus with variable magniﬁcation from macro to micro.The technology requires incident excitation light as well as detection of ﬂuorescence emission.Many different types of cancer models can be used for whole-body imaging,including orthotopic,colon 1,prostate 2,pancreas 3,bone 4,brain 5and other cancer models 6.The relative transparency of the footpad reduces the scatter of ﬂuorescent light emitted from the tumor,and the relatively few resident blood vessels makes it an excellent tumor transplantation site for whole-body tumor angio-genesis imaging 7.Many applications of GFP whole-body imaging have already been made to non-invasively visualize cancer 6,8,9,gene expression 10,graft vs.host disease 11and infectious disease 12in animal models.Estimating the intensity of GFP ﬂuorescence is complicated by variations in the exciting illumination with time and across the imaging area.These factors are corrected for by using the intrinsic red ﬂuorescence of mouse skin as a baseline to correct the increase over intrinsic green ﬂuorescence due to GFP 10.This can be done because there is relatively little red luminance in the GFP radiance.Consequently,the green ﬂuorescence is calculated relative to red based on red and green channel composition in the skin images 10.Therefore,some limits might occur when only a few cells are present in or on a deep organ.These limits can be readily overcome by using skin-ﬂap techniques 13.The GFP approach has several important advantages over other optical approaches to imaging tumor growth in vivo .In compa-rison with the luciferase reporter,GFP has a much stronger signal,and therefore can be used to image unrestrained animals —irradiation with non-damaging blue light is the only step needed.Images can bep u o r G g n i h s i l b u P e r u t a N 6002©n a t u r e p r o t o c o l s/m o c .e r u t a n .w w w //:p t th Figure 1|Comparison of external and internal images of bone metastasis.(a )External images of tumors in the skeletal system including the skull (small arrowheads),scapula (thick arrows),spine (ﬁne arrows),and liver metastasis (hollow arrowheads)in a dorsal view of a live,intact nude mouse.(b –i )Images of the exposed skeletal metastases.Bars,1280m m 1.NATURE PROTOCOLS |VOL.1NO.3|2006|1429captured with fairly simple apparatus,and there is no need for total darkness.The ﬂuorescence intensity of GFP is strong 14–17and the protein sequence of GFP has also been ‘humanized’,which enables it to be highly expressed in mammalian cells 18.Importantly,unlike lucifer-ase,ﬂuorescent proteins come in a multitude of colors 19,allowing for multiple events to be imaged.In addition,GFP ﬂuorescence is relatively unaffected by the external environment,as the chromaphore is protected by the three-dimensional structure of the protein 20.A triple fusion reporter vector harboring a Renilla luciferase reporter gene,a reporter gene encoding a monomeric RFP ,and a mutant herpes simplex virus type thymidine kinase was tested in vivo .A highly sensitive cooled charge-coupled device (CCD)camera that is compa-tible with both luciferase and ﬂuorescence imaging compared these two signals from the fused reporter gene using a lentivirus vector in 293T cells implanted in nude mice.The signal from RFP was found to be approximately 1000times stronger than luciferase 21.The weak signal from luciferase necessitates photon counting,with the construction of a pseudo-image in vivo rather than true imaging,therefore greatly reducing resolution and precluding the in vivo cellular imaging that is an important feature of GFP imaging.In addition,the rapid clearance of the injected luciferase results in an unstable signal that makes comparison of data difﬁcult 22.The stronger signals from ﬂuorescent proteins allow much more cost-efﬁcient instrumentation.T o overcome limits on ﬂuorescent protein imaging imposed by the skin,reversible skin-ﬂap window models have been developed that allow single-cell imaging on most organs of the mouse 23.The main advantage of luciferase-based imaging is that no excitation light is required,unlike ﬂuorescence imaging.This feature of luciferase-based imaging could allow deeper imaging than with ﬂuorescence,because excitation light is scattered and attenuated as it goes through skin,body tissues and ﬂuids.See T able 1for a comparison of GFP and luciferase imaging.MATERIALSREAGENTS.Immunocompetent and immunodeﬁcient mice (Charles River;Taconic;Harlan T eklad;see REAGENT SETUP).Cell lines,such as those derived from human cancer,to be transfected with genes coding for ﬂuorescent proteins (American Type Culture Collection (ATCC)).Enhanced GFP gene (Clontech Laboratories,Inc.).RFP (DsRed2)gene (Clontech Laboratories,Inc.).Retroviral vector pLEIN (Clontech Laboratories,Inc.).Retroviral vector pLNCX (Clontech Laboratories,Inc.).Retroviral pLACX vector (Clontech Laboratories,Inc.).Retroviral pFB-GFP vector (Clontech Laboratories,Inc.).vAd-GFP (Quanturn).Supernatants of PT67-GFP cells,PT67-RFP cells,PT67H2B-GFP cells (Clontech Laboratories Inc.).Growth medium (normal and selective),appropriate for cell culture (Life T echnologies).HEPES buffer (20mM,pH 7.2;Sigma).DOTAB reagent (Boehringer).LipofectAMINE Plus (Life T echnologies).Cloning cylinders (Bel-Art Products).Anesthetic reagents (ketamine,xylazine,acepromazine maleate,isoﬂuorane)(Butler Animal Health Supply).Nair (Carter-Wallance).G418Neomycin (Life T echnologies).PT67packaging cells (Clontech Laboratories Inc.)EQUIPMENT.OV100Small Animal Imaging System (Olympus Corp.).Leica ﬂuorescence stereo microscope model LZ12(Leica).Leica MZ6stereo microscope (Nussloch).Hamamatsu C5810three-chip cooled color CCD camera (Hamamatsu Photonics Systems).Lightools Fluorescent Imaging System (Lightools Research).Sony VCR model SLV-R1000(Sony Corp.).Image Pro Plus 4.0software (Media Cybernetics).1ml 27G2latex-free syringe (Becton Dickinson).25m l Hamilton syringe (Fisher Scientiﬁc).Humidiﬁed incubator with an atmosphere of 5%CO 2(Hotpack).Blue LED ﬂashlight (LDP LLC).D470/40excitation ﬁlter (Chroma T echnology).GG475emission ﬁlter (Chroma T echnology).Culture dishes,including 6-well and 96-well dishes (Fisher Scientiﬁc).Cloning cylinders (Bel-Art Products).Lipofectamine Plus transfection kit (Life Science)REAGENT SETUPImmunocompetent and immunodeﬁcient mice !CAUTION All animalstudies are conducted in accordance with the principles and procedures outlined in the National Institutes of Health National Research Council’s Guide for the Care and Use of Laboratory Animals (available at /readingroom/)under assurance number A3873-1.Animals are kept in a barrier facility under high-efﬁciency particulate air (HEPA)ﬁltration.Mice are fed with autoclaved laboratory rodent diet (T ecklad LM-485,Western Research Products).Retroviral pLACX vector !CAUTION The National Institutes of Health and Center for Disease Control have designated retroviruses as Level 2organisms.This requires the maintenance of a Biosafety Level 2facility,includingperforming the work in a limited-access area,posting biohazard warning signs,minimizing the production of aerosols,decontaminating potentially infectious waste before disposal and taking precautions with sharps.For more information on Biosafety Level 2,see the following reference:Biosafety in Microbiologial and p u o r G g n i h s i l b u P e r u t a N 6002©n a t u r e p r o t o c o l s/m o c .e r u t a n .w w w //:p t t h Figure 2|Whole-body ﬂuorescence imaging allows the visualization of lymphoma dissemination.At comparable lymph node (LN)enlargements (e.g.,axillar LN,see arrows),p53-null and Bcl2-overexpressing lymphomas are much more disseminated,inﬁltrating liver,kidneys,lungs (marked)and brain,whereas the control (ctrl.)murine stem cell virus-based retroviral vectors (MSCV)lymphoma is restricted to the lymphoid compartment 24.1430|VOL.1NO.3|2006|NATURE PROTOCOLSBiomedical Laboratories ,3rd Edn HHS Pub.#(CDC)93-8395(U.S.Department of Health and Human Services,PHS,CDC,NIH,1993)EQUIPMENT SETUPWhole-body imaging equipment Use an Olympus OV100Small Animal Imaging System,containing an MT-20light source (Olympus Biosystems)and DP70CCD camera (Olympus),for whole-body imaging in live mice at variable magniﬁcation.The optics of the OV100ﬂuorescence imaging system have been specially developed for macroimaging as well as microimaging,with high light-gathering capacity.The instrumentincorporates a unique combination of high numerical aperture and long working distance.Five individually optimized objective lenses,parcentered and parfocal,provide a 105-fold magniﬁcation range for seamless imaging of the entire body down to the subcellular level without disturbing the animal.The OV100has the lenses mounted on an automated turret with a high magniﬁcation range of Â1.6to Â16and a ﬁeld of view ranging from 6.9–0.69mm.The optics and antireﬂective coatings ensure optimal imaging of multiplexed ﬂuorescent reporters in small animals.High-resolution images are captured directly on a PC (Fujitsu Siemens,Celsius W340,Model MTR-D2156).An equivalent model can also be used.Images are processed for contrast and brightness and analyzed with the use of Paint Shop Pro 8(Corel Corp.)and Cell (Olympus Biosystems).Many other ﬂuorescence imaging systems can also be used for dual-color tumor–host imaging.For example,a Leica ﬂuorescence stereo microscope (model LZ12)equipped with a mercury 50-W lamp power supply can be used.Selective excitation of GFP is produced through a D425/60band-pass ﬁlter and 470DCXR dichroic mirror.Emitted ﬂuorescence is collected through a long-pass ﬁlter (GG475).Under anesthesia,the experimentalanimals can be examined with the microscope and the images can be acquired with a Hamamatsu C5810three-chip cooled color CCD camera.Images can also be processed for contrast and brightness and analyzed with the use of Image Pro Plus software.High-resolution images of 1,024Â724pixels can be captured directly on a computer or continuously through video output on a high-resolution Sony VCR,model SLV-R1000(Sony Corp.).Simpler systems such as a light box with appropriate ﬁlters and camera or even a blue light LED ﬂashlight with appropriate ﬁlters can be used for macroimaging (see below).PROCEDUREGFP retrovirus production1|For a GFP expression vector,use the pLEIN or equivalent retroviral vector expressing enhanced GFP and the neomycin resistance gene on the same bicistronic message.2|Use PT67,an NIH3T3-derived packaging cell line,expressing the 10A1viral envelope to produce retrovirus.Culture PT67cells in DMEM medium supplemented with 10%(vol/vol)heat-inactivated FCS.It takes approximately 3d for the cells to reach B 70%conﬂuence after seeding of 3Â105PT67cells in a 25mm 2ﬂask with DMEM medium containing 10%FCS.3|For vector production,use PT67packaging cells,at 70%conﬂuence.Plate PT67cells on a 60-mm dish at 60–80%conﬂuence 12h before e 10m g of pFB-GFP with the Lipofectamine Plus transfection kit.Add 7m l of pre-complexed pFB-GFP DNA in 87m l of serum-free medium and then add 6m l Lipofectamine reagent in a tube;mix and incubate at room temperature (22–261C)for 15min.4|Dilute 4m l of Lipofectamine in 96m l serum-free medium in a second tube.Mix and incubate at room temperature for 15min.5|Combine pre-complexed DNA and diluted Lipofectamine reagent;then mix and incubate at room temperature for 15min.6|While the complexes are forming,replace medium on the cells with 800m l serum-free DMEM.Add the DNA–Lipofectamine reagent complex to the dish with cells containing fresh DMEM.Mix the complexes into the medium gently;incubate at 371C,5%CO 2for 4h.7|After 4h incubation,increase volume of medium to 5ml.Incubate at 371C,5%CO 2for 24h.8|After 24h incubation,clone the packaging cells by limit dilution in 96-well plates where cells are plated to a density of less than one cell per well.p u o r G g n i h s i l b u P e r u t a N 6002©n a t u r e p r o t o c o l s/m o c .e r u t a n .w w w //:p t t h Figure 3|Whole-body imaging of a brain tumor.Real-time whole-body imaging of a U87-GFP human glioma growing in the brain of a nude mouse at (a )1week,(b )3weeks and (c )5weeks after surgical orthotopic implantation 5.TABLE 1|Comparison of optical imaging methods for tumor growth and metastasis 28.ParameterGFP/RFPLuciferaseReferenceStrength of signal6.6x 109pixels s –1cm –2steradian –17.4x 106pixels s –1cm –2steradian –121Minimum number of cells imageable in vitro 130029,30Minimum number of cells imageable in vivo 13,00023,29,31,32Need for substrate No Yes 23,29,32Need for anesthesia NoYes23,32Method of visualization Direct imagingPhoton-counting (pseudo-image)1,32Multi-color imaging Yes No 23Stability of signalYes No 6,22Need for excitation lightYesNo6,32NATURE PROTOCOLS |VOL.1NO.3|2006|14319|Examine the cells by ﬂuorescence microscopy 48h post-transduction.10|For selection,culture the cells in the presence of 300,400,500–2000m g ml –1G418,increased in a stepwise manner,to select for a clone producing high amounts of a GFP retroviral vector (PT67-GFP).Culture the cells for 1–2days in eachconcentration of G418.High-viral-titer production clones of GFP PT67cells are identiﬁed with 3T3cells used for virus titering.Clones with titer higher than 106plaque-forming units (pfu)are used for GFP vector production.m CRITICAL STEP Increasing the level of G418in a stepwise manner is very important to induce the expression of the transgene.This procedure assures high-level production of GFP retrovirus.RFP retrovirus production11|Insert the Hin dIII/Not I fragment from pDsRed2,containing the full-length red ﬂuorescent protein cDNA,into the Hin dIII/Not I site of pLNCX2that has the neomycin resistance gene to establish the pLNCX2-DsRed2plasmid.12|Incubate PT67cells at 70%conﬂuence for 24h at 371C.Lipofectamine reagent is used as described in Steps 3–8to transfect the pLNCX2-DsRed2vector into the PT67cells.13|Culture the cells in the presence of 200–1000m g ml –1of G418to select a clone producing high amounts of RFP retroviral vector (PT67-DsRed2).Culture the cells for 1–2d in each concentration of G418in step-wise increases of 100m g ml –1.m CRITICAL STEP This procedure assures high-level production of RFP retrovirus as described in Step 10.Production of histone H2B-GFP vector14|Insert the histone H2B-GFP fusion gene at the Hin dIII/Cla I site of the pLHCX retrovirus that has the hygromycin resistance gene.15|To establish a packaging cell clone producing high amounts of a histone H2B-GFP retroviral vector,transfect the pLHCX histone H2B-GFP plasmid in PT67cells using the same methods described above for PT67-DsRed2(Step 12).16|Culture the transfected cells in the presence of 200–400m g ml –1hygromycin to establish stable PT67H2B-GFP packaging cells.The amount of hygromycin is increased stepwise as described above for G418.m CRITICAL STEP This procedure assures high-level production of histone H2B-GFP retrovirus.RFP or GFP gene transduction of tumor cell lines17|For RFP or GFP gene transduction,use 20%conﬂuent cancer cells.12–18h before infection with GFP or RFP retrovirus,plate the target cells at a cell density of 1–2Â105per 60mm plate.18|For retroviral infection,collect conditioned medium from packaging cells (PT67/pFB GFP or PT67/pLNCX2-DsRed2)and ﬁlter medium through a 0.45m m polysulfonic ﬁlter.Add virus-containing ﬁltered medium to target cells.Add polybrene to a ﬁnal concentration of 8m g ml –1.Incubate cells for 24h at 371C.19|Replace medium with DMEM and 10%(vol/vol)FCS after 24h incubation.20|Check for GFP-or RFP-expressing cells by ﬂuorescence microscopy.21|Harvest tumor cells with trypsin/EDTA and subculture them at a ratio of 1:15in a selective medium that contains 50m g ml –1of G418.22|To select brightly ﬂuorescent cells,increase the level of G418to 800m g ml –1in a stepwise manner.Culture the cells for 1–2d in each concentration of G418,using at least four different concentrations.m CRITICAL STEP Increasing the level of G418in a stepwise manner is very important to induce the expression of the transgene.This procedure ensures high-level production of GFP or RFP in the cells.23|Isolate clones expressing GFP or RFP with cloning cylinders by trypsin/EDTA and amplify them in DMEM and 10%FCS in the absence of selective agent.Further select cells for brightness and stability.m CRITICAL STEP This step ensures that the cells will stably express GFP or RFP in the absence of antibiotic selection,which is the case in vivo .Double RFP and histone H2B-GFP gene transduction of cancer cells24|To establish dual-color cancer cells,use clones of cancer cells expressing RFP in the cytoplasm at 70%conﬂuence.Incubate RFP cancer cells,produced as described above (Steps 17–23),with the retroviral-containing medium supernatants of PT67H2B-GFP cells and the above culture medium for 48h at 371C.To obtain the double transformants,incubate cells with hygromycin 48h after transfection and select as described above (Step 16).p u o r G g n i h s i l b u P e r u t a N 6002©n a t u r e p r o t o c o l s/m o c .e r u t a n .w w w //:p t t h 1432|VOL.1NO.3|2006|NATURE PROTOCOLSEstablishment of imageable tumor models25|A number of options are available for establishing tumor models using ﬂuorescent protein-expressing tumor cells,including cell injection,surgical orthotopic implantation and DNA expression models of organs.(A)Cell injection to establish experimental metastasis model(i)Harvest ﬂuorescent protein–expressing tumor cells by trypsinization using 0.25%(wt/vol)trypsin for 3min at 371C.(ii)Wash cells three times with cold serum-free medium using a tabletop centrifuge at 2,000rpm for 5min at room temperature.(iii)Resuspend the cells in approximately 0.2ml of serum-free medium.(iv)Within 30min of harvesting,inject 6-week-old GFP-C57CL/6or nude (nu /nu )GFP mice with 106tumor cells into thelateral tail vein or subcutaneously,in a total volume of 0.2ml using a 1ml 27G2latex-free syringe.m CRITICAL STEP Cells in suspension can lose viability over time and therefore should be injected as soon as possible.(v)For liver colonization,inject ﬂuorescent protein–expressing cells directly into the portal vein under anesthesia (please see below for details on inducing anesthesia).(B)Subcutaneous injection of cancer cells(i)Collect cancer cells by trypsinization with 0.25%trypsin for 3min at 371C.(ii)Wash cells three times with cold serum-containing medium using a tabletop centrifuge at 500g for 5min at room temperature,and then keep on ice.(iii)Inject 6-week-old GFP male C57BL/6or GFP nude mice subcutaneously with 1Â106cancer cells that were collected andwashed.This is done by inoculating cells by subcutaneous injection of the dorsal skin of the mouse in a total volume of 50m l of cell culture medium within 40min of collection.(C)Surgical orthotopic implantation (SOI)to establish spontaneous metastasis model(i)Induce anesthesia with ketamine mixture (10m l ketamine HCL,7.6m l xylazine,2.4m l acepromazine maleate and inject subcutaneously).(ii)Perform all procedures of the operation under a Â7magniﬁcation microscope (Leica MZ6).(iii)Isolate ﬂuorescent protein-expressing tumor fragments (1mm 3)from subcutaneously growing tumors,which were formedfrom injected RFP-or GFP-expressing tumor cells (see Step 17),by mincing tumor tissue.After proper exposure of the target organ,implant three tumor fragments per mouse.(iv)Using an 8-0surgical suture,penetrate the tumor fragments and suture the fragments onto the target organ.m CRITICAL STEP Orthotopic implantation of tumor fragments results in higher spontaneous metastatic rates than injection of a cell suspension.(v)Keep animals in a barrier facility under HEPA ﬁltration.(D)Using the footpad to establish an imageable angiogenesis model(i)Subcutaneously inject cancer that stably expresses GFP into the footpad of 6-week-old nude mice.(E)Imageable gene expression models(i)For the DNA expression models,vAd-GFP is delivered to various organs for subsequent whole-body imaging.(F)DNA expression model in the brain(i)Induce anesthesia with the ketamine mixture as described above.(ii)Make an upper midline scalp incision to expose the parietal bone of the skull.m CRITICAL STEP This step and all subsequent steps should be performed with a Â7magniﬁcation stereo microscope (Leica MZ12).(iii)Inject 20m l of recombinant adenovirus in phosphate-buffered saline (PBS)with 10%(vol/vol)glycerol containing8Â1010pfu ml –1of vAd-GFP per mouse into the skull using a 1ml 27G1/2latex-free syringe.m CRITICAL STEP Plug the puncture hole in the skull with bone wax in order to seal the skull.(iv)Close the incision in the scalp with a 7-0surgical suture in one layer.(G)DNA expression model in the liver(i)Induce anesthesia with the ketamine mixture as described above.(ii)Make an upper midline abdominal incision to expose the portal vein.m CRITICAL STEP This step and all subsequent steps should be performed with a Â7magniﬁcation stereo microscope (Leica MZ12).(iii)Inject 100m l of PBS with 10%glycerol containing 8Â1010pfu ml –1vAd-GFP per mouse into the portal vein using a 1ml39G1latex-free syringe.m CRITICAL STEP For hemostasis,press the puncture hole in the portal vein with sterile cotton for about 10seconds in order to prevent excess blood loss.(iv)Close the incision in the abdominal wall with a 7-0surgical suture in one layer.(H)DNA expression model in the pancreas(i)Induce anesthesia with the ketamine mixture as described above.(ii)Make an upper midline abdominal incision to expose the pancreas.p u o r G g n i h s i l b u P e r u t a N 6002©n a t u r e p r o t o c o l s/m o c .e r u t a n .w w w //:p t t h NATURE PROTOCOLS |VOL.1NO.3|2006|1433m CRITICAL STEP This step and all subsequent steps should be performed with a Â7magniﬁcation stereo microscope (Leica MZ12).(iii)Inject 100m l of PBS with 10%glycerol containing 8Â1010pfu ml –1vAd-GFP per mouse into the pancreas using a1ml 39G1latex-free syringe.m CRITICAL STEP Press the puncture hole for about 10seconds with sterile cotton for hemostasis in order to prevent excess blood loss.(iv)Close the incision with a 7-0surgical suture in one layer.(I)DNA expression model in the prostate(i)Induce anesthesia with the ketamine mixture as described above.(ii)Make a lower midline abdominal incision to expose the bladder and prostate.m CRITICAL STEP This step and all subsequent steps should be performed with a Â7magniﬁcation stereo microscope (Leica MZ12).(iii)Inject 30m l of PBS with 10%glycerol containing 8Â1010pfu ml –1vAd-GFP per mouse in the prostate using a 1-ml 39G1latex-free syringe.m CRITICAL STEP Press the puncture hole in the prostate for about 10seconds with sterile cotton for hemostasis in order to prevent excess blood loss.(iv)Close the incision with a 6-0surgical suture in one layer.(J)DNA expression model in the bone marrow(i)Induce anesthesia with the ketamine mixture as described above.(ii)Open the skin on the hind leg with a 1-cm incision to expose the tibia.m CRITICAL STEP This step and all subsequent steps should be performed with a Â7magniﬁcation stereo microscope (Leica MZ12).(iii)Insert a 27-gauge needle with a latex-free syringe in the bone marrow cavity.(iv)Inject a total volume of 20m l of PBS with 10%glycerol (8Â1010pfu/ml)vAd-GFP per mouse into the bone marrow cavity.m CRITICAL STEP Plug the puncture hole in the bone with bone wax and close the incision with a 6-0surgical suture in order to seal the bone.26|A number of methods are available for whole-body imaging of mice,including chamber,microscopy,ﬂashlight imaging and light-box imaging.(A)Whole-body imaging with a microscope(i)Use a Leica ﬂuorescence stereo microscope (model LZ12)equipped with a mercury 50W lamp power supply or equivalent.(ii)Produce selective excitation of GFP through a D425/60band-pass ﬁlter and 470DCXR dichroic mirror.(iii)Collect emitted ﬂuorescence through a long-pass ﬁlter (GG475)on a Hamamatsu C5810three-chip cooled color CCDcamera or equivalent.(iv)Process images for contrast and brightness with the use of Image Pro Plus 4.0software or equivalent.(v)Capture high-resolution images of 1,024Â724pixels directly on an IBM PC or continuously through video output on a high-resolution Sony VCR,model SLV-R1000or equivalent.(vi)In the case of C57BL/6mice,remove hair with depilatory cream (e.g.,Nair)or by shaving.m CRITICAL STEP Hair is highly autoﬂuorescent,so improper removal of hair will result in low-quality images.(B)Whole-body imaging with a ﬂashlight(i)Use a blue LED ﬂashlight with an excitation ﬁlter (midpoint wavelength peak of 470nm)and a D470/40emission ﬁlter for whole-body imaging of RFP-or GFP-expressing mice with RFP-expressing tumors growing in or on internal organs.m CRITICAL STEP Correct ﬁlters are necessary to eliminate tissue autoﬂuorescence.(ii)Acquire images with a digital camera such as a Nikon Cool-PIX or a simple CCD camera and store on a PC as described above.(iii)In the case of C57BL/6mice,remove hair with depilatory cream or by shaving.m CRITICAL STEP Hair is highly autoﬂuorescent,so improper removal of hair will result in low-quality images.(C)Whole-body imaging in a light box(i)Perform whole-body imaging in a ﬂuorescent light box illuminated by ﬁberoptic lighting at 470nm.(ii)Collect emitted ﬂuorescence through a GG475long-pass ﬁlter on a Hamamatsu C5810three-chip cooled color CCD camera or equivalent (use of separate band-pass ﬁlters for RFP or GFP emission allows a monochrome camera to be used).(iii)Capture high-resolution images of 1,024Â724pixels directly on an IBM PC or equivalent.(iv)Process images for contrast and brightness with the use of Image Pro Plus 4.0software or equivalent.(v)In the case of C57BL/6mice,remove hair with depilatory cream or by shaving.m CRITICAL STEP Hair is highly autoﬂuorescent,so improper removal of hair will result in low-quality images.(D)Whole-body imaging in a chamber(i)Perform whole-body imaging in an Olympus OV100imaging system with 470nm excitation light originating from an MT-20light source.p u o r G g n i h s i l b u P e r u t a N 6002©n a t u r e p r o t o c o l s/m o c .e r u t a n .w w w //:p t t h 1434|VOL.1NO.3|2006|NATURE PROTOCOLS。

Lepeophtheirus salmonis

Aquacultural Engineering 21(1999)33–48An optical method for the detection of sea lice,Lepeophtheirus salmonisR.D.Tillett,C.R.Bull,J.A.Lines *Silsoe Research Institute ,Silsoe ,Bedford ,MK 454HS ,UKReceived 19April 1999;accepted 29June 1999AbstractDevelopments towards a novel video camera based system for estimating the sea lice burden of freely swimming salmon are reported.The spectral reﬂectance of sea lice and salmon skin were measured over the wavelength range 400–1100nm.Canonical variate analysis was then used to identify a combination of reﬂectances that maximises the differences between skin and sea lice.This is shown to provide good discrimination when the lice are attached to the lighter underside of the ﬁsh and a degree of discrimination when the lice are attached to the darker areas.The results of this analysis were used to develop a simple video based discrimination system.An image of the salmon is synthesised from the ratio of grey levels of images taken through narrow band pass ﬁlters at wavelengths of 700and 800nm.This enhances the visibility of the lice and suppresses variations in the skin colour.Further development of this technique could lead to an automated passive system for estimating lice burden.©1999Elsevier Science B.V.All rights reserved.www.elsevier.nl /locate /aqua-online1.IntroductionSea lice are one of the most serious and costly diseases faced by the salmon industry.Estimates of the costs incurred due to lice vary widely but are likely to exceed £20million per annum in both Scotland and Norway (Kvenseth,1997;Sinnott,1998;Smith,1999).These costs are incurred through low growth and food conversion ratio,stock losses,secondary diseases and harvest price mark down as well as the costs of monitoring and treating the ﬁsh.*Corresponding author.Tel.:+44-1525-860156;fax:+44-1525-860000.E -mail address :jeff.lines@ (J.A.Lines)0144-8609/99/$-see front matter ©1999Elsevier Science B.V.All rights reserved.PII:S 0144-8609(99)00022-934R.D.Tillett et al./Aquacultural Engineering21(1999)33–48The most wide spread sea louse is Lepeophtheirus salmonis.It has a life cycle which begins with several free swimming planktonic stages during which the lice are typically less than1mm long(Johnson and Albright,1991).This is followed by chalimus stages where the lice areﬁrmly attached to the salmon.At the end of these stages the lice are up to2.5mm long.Theﬁnal stages comprise two pre adult stages and an adult stage.An adult louse is around5–8mm long with the female trailing egg sacks a further6or8mm in length.At a temperature of10°C,development from an egg to a mature adult takes around40days for a male and52days for a female(Schram,1993).Infestation of salmon tends to begin with lice attaching themselves behind the dorsalﬁn.As infestation becomes heavier,the rest of the back,particularly the top of the head becomes colonised.Heavily infectedﬁsh also have lice on the lighter underside,tail andﬁns.The pre-adult and adult stages cause substantially more damage to the host than the earlier stages.Grimnes and Jakobsen(1996)suggest that infection intensities above30salmon lice larvae perﬁsh may cause the death of Atlantic salmon post-smolt soon after the lice reach their pre-adult stage. There exist a range of possible treatments for sea lice,none of which are entirely satisfactory.Most of these treatments rely on regular monitoring of lice numbers to identify the optimum time for treatment.In order to minimise the costs of this process,a rather small sample ofﬁsh are used and these are caught from the surface of the sea cage with minimal disruption to the salmon.(Bakke Jøssund,1995; Jackson,1998;Treasurer and Grant,1998).It is to be expected that this sampling procedure gives rise to large uncertainty in the estimates of the lice burden.The research reported in this paper indicates a method for enhancing the contrast between lice andﬁsh skin by synthesising a video image from images captured at two speciﬁc wavelengths.This might allow automatic or manual estimation of the sea lice burden of freely swimmingﬁsh.The reﬂection properties ofﬁsh skin and sea lice wereﬁrst examined to identify spectral differences which might facilitate discrimination.The variation in reﬂec-tance from a material over a wavelength range due to the presence of different absorbing compounds can give an identifying signature that allows it to be distinguished from another material of similar colouration.This is a technique that has found a number of applications in the sorting and identifying of agricultural and food materials(Mohesenin,1984;Bull,1993;Bull et al.,1995).We show how observed differences in spectral reﬂection properties have been used to identify characteristic wavelengths which can be used to discriminate between lice and salmon skin.Following this spectral analysis,video images were recorded at the characteristic wavelengths identiﬁed.These were then combined to synthesise an image in which discrimination between salmon skin and sea lice is substantially greater than in a normal video image.This work has demonstrated the possibility of an underwater video based lice detection system.Further work is required to examine the variability the spectra over a larger sample of salmon and lice,to test the system on live salmon and to optimise and enhance the discrimination.If successful the resulting underwater35 R.D.Tillett et al./Aquacultural Engineering21(1999)33–48video based sensing system could replace manual sampling of theﬁsh.This would lead to reductions in cost,labour andﬁsh stress.Further,because it is a process that might be achieved with some level of automation and at a range of depths,it may provide a more accurate view of changes in the sea lice burden throughout the whole cage population.2.Collection of spectral scansTwo sets of spectral scans were taken in this investigation.One set was used to characterise the light reﬂection and transmission properties of lice detached from the surface of the Atlantic salmon.A second set of scans was used to characterise the reﬂection properties of the lice on the surface of the salmon.The reﬂectance measurements were made using the system illustrated in Fig.1. This comprises a stabilised100W tungsten halogen light source,a bifurcated light guide and a monochromator.Light from the source was guided along one arm of the light guide onto theﬁsh or lice and the reﬂected light was collected into the second branch of the light guide and taken into an optical spectrum analyser (Monolight Instruments6101device).In the bifurcated light guide(Monolight Instruments3134)theﬁbres of the incoming and outgoing arms at the probe end are randomly mixed.Transmission measurements were made with the equipment conﬁgured as shown in Fig.2.Aﬁbre optic bundle conveyed light from the light source onto the sample.Transmitted light was collected and transferred to the spectrum analyser by a second set ofﬁbres.An optical spectrum analyser was used to examine the transmission and reﬂec-tance scans.The optical spectrum analyser splits the light into its component wavelengths using a diffraction grating and narrow entry and exit slits.In this case the slit widths were set up to give a spectral resolution of2.5nm.The scans were taken over a wavelength range of380–1100nm at2-nm intervals.In order to minimise spectral noise,the response was determined by integrating the signal over 100individual scans.In terms of light colour,380nm represents light at the violetFig.1.Schematic diagram of the reﬂection measurement system.36R.D.Tillett et al./Aquacultural Engineering21(1999)33–48Fig.2.Schematic diagram of the transmission measurement system.end of the visible spectrum,while1100nm is near infrared light.The upper wavelength limit of the visible spectrum(red)occurs at a wavelength of about780 nm(Hecht and Zajac,1979)The raw data from the optical spectrum analyser shows the optical response of the whole system and is therefore a function of the optical properties of the light source,guidingﬁbres,monochromator and detector as well as the optical properties of the sample.In order to determine the absolute reﬂectance or transmission characteristics of the sample alone,it is necessary to divide the measured spectrum by a reference spectrum obtained from either a fully reﬂective reference surface(for the reﬂectance measurements)or from the light that passes through the system with no sample present(for the transmission measurements).The reﬂective reference surface used in this work was Barium Sulphate,which is fully reﬂective in the visible and near infrared wavelengths.Measurements of the reﬂection spectra of the detached lice were made on lice removed from a salmon which had been killed during a normal commercial harvest and held on ice for24–36h.Spectra were obtained under two conditions.In the ﬁrst instance the lice were placed on the fully reﬂective reference surface.The bifurcated light probe illustrated in Fig.1was then placed in contact with each louse and the body reﬂectance determined.This was repeated for several lice.These measurements were then repeated with the lice placed on carbon black paper,in order to determine the level of reﬂectance from the lice when the material behind is strongly absorbing.Carbon black paper is extremely(and uniformly)absorbent in this wavelength range.Finally the transmission spectra of several different lice were determined by sandwiching each louse between narrowly separatedﬁbre bundles as illustrated in Fig.2.Measurements of the reﬂection spectra of lice on the surface of the salmon were made on30lice from four salmon.These were made within1h of theﬁsh being killed.Theﬁsh had not been cooled with ice.Measurements were taken by holding the bifurcated light probe in contact with these surfaces.Spectral reﬂectance measurements were also made of theﬁsh skin adjacent to each of the lice.TheR.D.Tillett et al./Aquacultural Engineering21(1999)33–4837 position of each louse on theﬁsh was recorded.The lice on theﬁsh and detached from theﬁsh,were all in the adult or pre-adult stages.Most were female and several had trailing egg strings.3.Description of spectral scans3.1.Scans of detached sea liceTypical reﬂectance scans for a detached sea louse are illustrated in Fig.3.The upper curve shows the louse reﬂectance when it is placed upon a fully reﬂecting standard surface and the lower curve,when it is placed on absorbing carbon blackFig.3.Reﬂectance scan of a louse placed on a standard reﬂectance surface(upper)and on carbon black paper(lower).38R.D.Tillett et al./Aquacultural Engineering21(1999)33–48Fig.4.Straight through transmission scan of a louse.paper.The louse on the reﬂecting surface has a fairly steady increase in body reﬂectance from400to850nm reaching a maximum of around50%.The reﬂectance thenﬂattens out and starts to fall towards1000nm.The dip at around 1000nm is probably due to water in the louse.Water has a strong and character-istic absorption band at970nm.The reﬂection scan for the same sea louse on the absorbing surface shows some of the same features with the reﬂectance increasing to a maximum at850nm,but the overall reﬂectance is much smaller and the absorption band at970nm is much less pronounced.The difference in reﬂectance magnitude between the upper and lower graphs in Fig.3suggests that the absorption of lice is small,enabling the light to propagate through it into the surface behind.When there is a reﬂective surface behind the louse,the light is multiply scattered from the louse onto the reference surface and back so a substantial proportion of the light returns to the probe.The multiple passes of the light through the louse caused by scattering and reﬂection from the inner surface of the louse increases the average path length of the light in the louse and so emphasises any absorption features(Bull,1990,1991).This is evident in the more pronounced dip due to the water absorption band at970nm in Fig.3. This weakly absorbing model suggests that a high transmission of light through the louse might be expected.Measurement of light transmission does not show this.A typical transmission measurement indicates a maximum straight through trans-mission of only6%(Fig.4).The transmission curve has similar features to the reﬂection scan up to850nm but then continues with increasing transmission into the near infrared.This low straight through transmission indicates that the lice have strong light scattering properties.Strong scattering by a weakly absorbing sample will result in most of the light that enters the sample exiting it but diffusely rather than in any particular direction.R.D.Tillett et al./Aquacultural Engineering21(1999)33–48393.2.Scans ofﬁsh skin and attached sea liceSample spectral scans taken from skin and lice are shown in Fig.5.These curves show two distinct groupings.The more reﬂective scans(the upper group of lines) are from the lighter regions of theﬁsh close to and below the lateral line,and of the lice attached to these regions.The lower reﬂection scans are from the darker regions of theﬁsh and lice on these areas.These data sets resemble those of the detached sea lice placed on the reﬂective surface and the carbon black paper respectively (Fig.3).Visual comparison of the spectral shapes of the scans on the two regions is difﬁcult due to the large differences in intensity.However,comparison is easier if these scans are normalised by dividing each scan by its average value.Signiﬁcant differences between the scans of the lice on the light and dark regions are still apparent.Those on the light skin show more signiﬁcant absorption bands,probably due to multiple scattering in the louse.The upper group of curves in Fig.5clearly show a difference between the spectral response of the lice and the skin.This is particularly pronounced in the 700–850nm region where the reﬂectance of the lice increases much more rapidly than the reﬂectance of the skin.There is much less difference between the scans of lice andﬁsh skin taken in regions where the surface of theﬁsh is dark.3.3.Analysis of spectra to identify characteristic differences between lice and skinA multivariate analysis technique known as Canonical Variate Analysis(Genstat 5Committee,1987)was used to quantify the differences between lice andﬁsh skin spectral responses.The scans wereﬁrst divided into those taken on the light areasFig.5.Reﬂection scans of light( )and dark( )ﬁsh skin regions and of lice attached to light( )and dark( )areas of theﬁsh.40R.D.Tillett et al./Aquacultural Engineering21(1999)33–48(13pairs of measurements)and those taken on the darker areas of theﬁsh(17pairs of measurements).This was done to maximise the chance of identifying spectral features that would enable discrimination in each of the broad categories.The spectra were then smoothed to remove random noise.Most of the rapid changes in reﬂectance that can be seen in Fig.3,for example,are due to noise signals and are unrelated to the optical properties of the sample object.These are particularly large at the low and high frequencies where the intensity of incident light was low.Measurement of the reﬂectance over a longer time would have reduced these substantially,however,new errors of a different nature might have been created as the sample was warmed by the light energy.Sampling errors can be reduced by smoothing the spectral scans.For this analysis,the spectra were smoothed over a20nm bandwidth,by replacing the reﬂectance at each wavelength R u with a local average R u*which is calculated as:R u*=111%n=5n=-5R u+2n(1)where the wavelength of the light is u and n enables a stepping through of the integrated wavelength band in the2-nm intervals.The smoothed points were calculated at10-nm intervals.To further reduce the inﬂuence of unreliable noisy data,the upper and lower wavelengths were truncated to limit the reﬂectance scans to wavelengths between410and990nm.Four scans from each group of scans(lice on light areas,light skin,lice on dark areas,dark skin)were then randomly selected and reserved for testing the results of the analysis.The remaining scans were used to determine whether the spectral data could be separated into the predeﬁned groups,salmon skin and lice.The canonical variate analysis(CVA)technique determines a linear combination of the reﬂec-tances at each wavelength that minimises the in-group variation(i.e.variation in the skin or lice scans)and maximises the between group variations.The canonical variate score S can then be calculated for each spectral scan.It is calculated as:S=W u1R u1+W u2R u2+W u3R u3…W unR un(2)where R u1is the reﬂection at theﬁrst wavelength of the range used in the CVA,R unis the reﬂectance at the last wavelength and W un is the weighting of that wavelengthin the canonical variate vector.Once these weightings have been calculated,they can be applied to the four sets of spectral scans from each group which were reserved for testing the analysis results.The canonical spectral scores for the training and test sets taken from the lighter skin areas are shown in Fig.6.The training set is shown as squares,whereas the test set plotted as triangles.The training data clearly separate into the two predeﬁned groups and the test set data are also well separated which conﬁrms the validity of the separation.The weightings of the canonical variate are given in Fig.7.This shows smooth and probably reliable features in the weightings between600 and900nm that correspond to the differences in the spectral features observed in Fig.5.41R .D .Tillett et al ./Aquacultural Engineering 21(1999)33–48Fig.6.Canonical variate scores for the training ( )and test set ( )of smoothed spectral scans from the lighter regions for the lice /skin groupings.The canonical scores for the training and test sets for the spectral scans taken from the darker areas of the ﬁsh are shown in Fig.8.Although the separation here is poorer than on the light areas,separation has been achieved for the majority of scans.This is in agreement with the observations made on Fig.5where it was noted that the spectral differences between the lice scans and skin scans in these darker regions are smaller.The spectral weightings of the canonical vector in Fig.9show a smoothly varying feature only between 780and 880nm.This implies that muchFig.7.The weightings W u n of the canonical variate vector for the smoothed spectral scans obtained on the lighter regions of the ﬁsh.42R .D .Tillett et al ./Aquacultural Engineering 21(1999)33–48Fig.8.Canonical variate scores for the training ( )and test set ( )of smoothed spectral scans from the darker regions for the lice /skin groupings.of the separation between the lice and skin scans in the darker regions may be unreliable.One would expect from this that the separation of the test scans would be poorer than the training set.Fig.8gives some indication of this with one of the scores for the skin test set overlapping in value with the scores of the lice group.Fig.9.The weightings W u n of the canonical variate vector for the smoothed spectral scans obtained on the darker regions of the ﬁsh.Fig.10.Transmission characteristics of narrow bandﬁlters.4.Collection of video images at selected wavelengthsHaving identiﬁed differences in the spectra of the light reﬂected from the lice and salmon skin it was of interest to examine the potential for using video images to discriminate between salmon skin and lice on the basis of these differences.The clearest distinguishing feature between the spectra of the lice and skin on the lighter areas of theﬁsh is the rise in reﬂectance between700and800nm,(Fig.5).The weightings calculated in the Canonical Variate Analysis(see Fig.7)show this feature as a strong downward slope from700to800nm.Video images of the salmon and lice were therefore collected at these wavelengths and processed to enhance this distinction.The equipment used for collecting the images comprised a Pulnix monochrome camera with a25mm lens and a rotatingﬁlter holder connected to a Matrox Meteor frame grabber installed in a PC.Theﬁlters were narrowband glassﬁlters from InfraRed Engineering with transmission characteristics as shown in Fig.10.The camera was mounted approximately80cm above theﬁsh surface,viewing theﬁsh in a controlled light chamber to ensure a reasonably constant and diffuse illumination level.Images of768×576pixels were collected with eachﬁlter,for a number of views of lice on theﬁsh surface.One pair of images is shown in Fig.11. The view is of the left side of the tail with the top surface of theﬁsh on the right of theﬁgure.Five lice are in the image,although not all are easily visible.These images were taken on the single salmon that was used to supply lice for the study of detached lice rather than that for which the Canonical Variate Analysis had been made.5.Generation of synthesised imageThe images taken at700and800nm were combined by taking the ratio of the grey levels of corresponding pixels as follows:Ir[i,j]=128×I7[i,j]I8[i,j]if0B I8[i,j]and128×I7[i,j]I8[i,j]5255=0if I8[i,j]=0=255if128×I7[i,j]I8[i,j]\255(3)where I7[i,j]is the grey level of the pixel in the i th column and j th row of the700 nm image,I8[i,j]is the equivalent pixel in the800nm image and Ir[i,j]is the equivalent pixel in the newly created ratio image.The scaling of the ratio assigns the grey level of128to a ratio of1,with a ratio of2or above appearing as white (grey level255).This creates a synthesised image which indicates by its grey levels the change in reﬂectance between wavelengths of700and800nm.The synthesised image created from Fig.11a and b is shown in Fig.11c.A steep gradient in the spectrum should give a darker area in the ratio image.Three lice are quite clearly visible in the ratio image.There are two other lice present on theﬁsh, marked in11c by arrows,which are not so clearly shown.It is also of interest to notice how much the grey level variation of the rest of theﬁsh surface has been reduced by the ratio technique.The image in Fig.11shows the situation for lice close to the midline and on the tailﬁn.Lice on the underside of theﬁsh showed greater contrast with theﬁsh surface in all three images(700,800nm and the ratio image).Lice on the darker (dorsal)surface of theﬁsh were difﬁcult to see in any of the three images.These results are consistent with the results of the spectrum analysis described earlier.Fig. 9shows little difference in weightings between700and800nm.Discrimination between lice and skin on this surface would probably be improved by using images taken at wavelengths of780and870nm.Images were also collected of lice on the salmon with theﬁsh immersed in a shallow tank of water,so that the water surface was just above theﬁsh surface.This gave aﬂat air-to-water interface through which theﬁsh was viewed,rather than the uneven surface given by a thinﬁlm of water over theﬁsh.These images are likelyFig.11.Images of lice on a salmon(a)700-nm image(b)800-nm image(c)synthesised ratio image.to be similar to those that would be collected by an underwater camera.The results of the images taken through the shallow water are similar to the results out of water,described above.6.Future developmentsFurther work is required to improve discrimination of lice on the dark surfaces. Fig.9indicates that the most stable differences are to be found between780and 870nm.Video images at these wavelengths need to be captured to demonstrate how well lice on the darker surfaces can be distinguished.Fig.7indicates that these wavelengths could also be suitable for discriminating lice on the lighter underside of ﬁsh.One of the problems associated with moving to longer wavelengths is the increasing absorption of light by the water.Jerlov(1976)reports the transmittance of light through sea water to be61%per metre at700nm,but only9%at750nm and18%at800nm.If the images are to be captured near the water surface, sensitive cameras may be needed to generate an adequate image.At any signiﬁcant distance beneath the water surface additional light at the required frequencies may also be needed since this component of the sun light will not penetrate far into the water column.Rainbow trout and therefore probably Atlantic salmon are relatively insensitive to light at these wavelengths so such illumination need not be visible to theﬁsh(Douglas,1983).The studies of the spectral properties of the detached lice indicated that the lice scattered light strongly.By using a directional light to illuminate theﬁsh it is anticipated that the light reﬂected from the scales will be directional whereas the lice will appear as secondary and diffuse light sources on the surface of theﬁsh.The potential of this technique for lice detection will be investigated further. Automatic interpretation of the images has not yet been studied.However, techniques for identifyingﬁsh and tracing their outline have been developed (McFarlane and Tillett,1997).A simple threshold technique could then be used to pick out the dark blobs of the lice,but this would also select some of the texture at scale edges,on theﬁns and at the edge of theﬁsh.A more sophisticated detection algorithm would therefore probably be necessary.These images show,however, that there is potential to use a non-contact technique to help detect the presence of lice on the sides or under surface of salmon.7.ConclusionsExamination of the spectral reﬂectance of sea lice and salmon skin has revealed distinguishing features in the reﬂectance spectrum which can be used to enhance the visibility of sea lice.These differences are particularly signiﬁcant when the lice are attached to the lighter areas of theﬁsh.This difference can be exploited using video images taken with band passﬁlters at light wavelengths of700and800nm.Theseimages can be combined to create a synthesised image with enhanced contrast between lice and salmon skin and reduced contrast due to other variations in surface colour.Discrimination of the lice on dark surfaces is more difﬁcult but may be enhanced using longer wavelengths of light(780and870nm).Sea lice are found to scatter light strongly.This might also be used to enhance the visibility of lice on the darker areas of skin.Further work is required to assess the potential of this technique for underwater inspection of free swimming salmon.Automatic interpretation of the images which would supply an estimate of the lice burden may be possible but it has not yet been investigated.AcknowledgementsThis work was supported by the Biotechnology and Biological Sciences Research Council of Great Britain.The authors gratefully acknowledge the assistance of Marine Harvest McConnell in this investigation and in particular that of David Mitchell,Simon Wadsworth and John Muckhart.ReferencesBakke Jøssund,T.J.,1995.Lusetelling som led i helsetjeneste forﬁskeoppdrett.Norske Vet-erinærtidsskrift107(2),114–119.Bull,C.R.,Mottram,T.,Wheeler,H.C.,1995.Optical teat inspection for automatic milking systems.Computers and Electronics in Agriculture12,121–130.Bull,C.R.,1990.A model of the reﬂectance of near infra-red radiation.Journal of Modern Optics37, 1955–1964.Bull,C.R.,pensation for particle size effects in near-infrared reﬂectance.The Analyst116, 781–786.Bull,C.R.,1993.A Review of sensing techniques which could be used to generate images of agricultural and food puters and Electronics in Agriculture8,1–29.Douglas,R.H.,1983.Spectral sensitivity of rainbow trout(Salmo gairdnerei).Rev.Can.Biol.Exp.42(2),117–122.Genstat5Committee,1987.Genstat5Reference Manual.Oxford Science Publications,pp.449–531. Grimnes,A.,Jakobsen,P.J.,1996.The physiological effects of salmon lice infection on post-smolt of Atlantic salmon.Journal of Fish Biology48(6),1179–1194.Hecht,E.,Zajac,A.,1979.Optics,4th edn.Addison Wesley,Reading.Jackson,D.,1998.Developments in sea lice management in Irish salmon farming.Caligus,4,December 1998,a newsletter funded under the EU Fair programme.Jerlov,N.G.,1976.Marine Optics.Elsevier,Amsterdam,p.52.Johnson,S.C.,Albright,L.J.,1991.The developmental stages of Lepeophtheirus salmonis.Canadian Journal of Zoology69(4),929–950.Kvenseth,P.G.,1997.Best current practice for lice control in Norway.Caligus,2,December,1997,a newsletter funded under the EU FAIR program.McFarlane,N.J.B.,Tillett,R.D.,1997.Fitting3D point distribution models ofﬁsh to stereo images.In: BMVC97Proceedings of the8th British Machine Vision Conference,8–11September1997.University of Essex,UK,vol.1,pp.330–339.。

热休克蛋白70促进急性肺损伤小鼠肺部炎症反应

热休克蛋白70促进急性肺损伤小鼠肺部炎症反应陈艳;王梓璇;冀彩丽;华梦晴;宋传旺【期刊名称】《华中科技大学学报:医学版》【年(卷),期】2022(51)2【摘要】目的探讨热休克蛋白70(heat shock protein 70,HSP70)对急性肺损伤(acute lung injury,ALI)小鼠发病的影响及其相关机制。

方法构建ALI模型小鼠,免疫印迹法检测肺组织中HSP70的表达情况,酶联免疫法检测支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中HSP70的分泌情况。

ALI小鼠经鼻滴HSP70抗体(anti-HSP70)后,抽取BALF,检测其中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)、白细胞介素6(interleukin 6,IL-6)、白细胞介素1β(interleukin 1β,IL-1β)和蛋白的含量,并计数中性粒细胞的数目;获取肺组织进行苏木精-伊红染色并计算肺湿/干重比。

以LPS刺激小鼠肺泡上皮细胞株MLE-12细胞,酶联免疫法检测培养上清液中TNF-α和IL-1β的含量。

不同浓度的HSP70(10~500ng/mL)刺激小鼠肺泡上皮细胞(alveolar epithelial cells,AECs)后,流式细胞术检测AEC吞噬凋亡细胞的情况。

结果与正常对照组小鼠相比,ALI小鼠肺组织中HSP70的表达及BALF中HSP70的分泌均增加(均P<0.05)。

与ALI组小鼠相比,经anti-HSP70鼻滴治疗后的ALI小鼠,其BALF中TNF-α、IL-6、IL-1β和蛋白的含量均降低(均P<0.05),中性粒细胞数目减少(P<0.05);其肺组织中炎性细胞浸润减少,肺湿/干重比降低(P<0.05)。

与LPS刺激组相比,anti-HSP70+LPS组MLE-12细胞培养上清液中TNF-α和IL-1β含量均减少(均P<0.05)。

热应激对小鼠神经元骨架蛋白和热休克蛋白70表达的影响

热应激对小鼠神经元骨架蛋白和热休克蛋白70表达的影响耿晓英;万琪;吴松笛;杨荣军【期刊名称】《解放军医学杂志》【年(卷),期】2006(31)4【摘要】目的观察不同温度下体外培养的小鼠皮层神经元的形态及骨架蛋白表达变化,以及与热休克蛋白70(HSP70)变化的关系.方法取小鼠胚胎大脑皮层进行神经元原代培养,7天后给予不同温度刺激,应用倒置相差显微镜观察刺激后神经元的形态变化,应用激光共聚焦扫描观察不同温度刺激后神经元中骨架蛋白(β-tubulin)、HSP70的表达变化.结果光镜观察见38℃时漂浮细胞增加,神经网络稀疏;39℃时部分细胞坏死;42℃时大部分细胞出现坏死,胞体碎裂,突起漂浮或消失.激光共聚焦扫描见高温(38～42℃)刺激后β-tubulin荧光强度低于37℃时,且温度愈高荧光强度降低愈明显;HSP70荧光强度呈钟形分布,39℃最高,37℃、42℃较低.结论热应激可以导致神经元形态变化,β-tubulin结构紊乱可能是其原因之一,HSP70也可能参与了该病理过程.【总页数】2页(P336-337)【作者】耿晓英;万琪;吴松笛;杨荣军【作者单位】西安市第四医院神经内科;710032,西安,第四军医大学西京医院神经内科;710032,西安,第四军医大学西京医院神经内科;710032,西安,第四军医大学西京医院神经内科【正文语种】中文【中图分类】R188.11【相关文献】1.磁刺激对小鼠海马原代神经元即刻早期基因和细胞骨架蛋白表达的影响 [J], 张展翅;马隽;栾峰;康林;苏玉红;王彦永;王铭维;崔慧先2.高温对小鼠神经元骨架蛋白及热休克蛋白70表达的影响 [J], 耿晓英;万琪;杨荣军;吴松笛3.中药复方对慢性热应激蛋鸡肺脏钙含量及热休克蛋白70表达量的影响 [J], 段凯文;宋晓琳;郭浩;高志民;石达友;郭世宁4.急性热应激对山羊血液生化指标及血淋巴细胞热休克蛋白70家族基因表达的影响 [J], 彭孝坤;赵天;黄晓瑜;张宇;邢晓南;张恩平5.热休克蛋白70上调表达对热应激猪小肠上皮细胞凋亡的影响 [J], 孙汇蕾; 仲庆振; 李明晔; MOLAWA M N因版权原因，仅展示原文概要，查看原文内容请购买。

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