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微生物资源及开发利用

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Bacterial charity work leads to population-wide resistance Henry H. Lee, Michael N. Molla, Charles R. Cantor & James J. Collins
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制药工程专业英语课文

Unit 1 Production of DrugsDepending on their production or origin pharmaceutical agents can be split into three groups:I .Totally synthetic materials (synthetics)，Ⅱ.Natural products，andⅢ.Products from partial syntheses (semi-synthetic products).The emphasis of the present book is on the most important compounds of groups I and Ⅲ一thus Drug synthesis. This does not mean，however，that natural products or other agents are less important. They can serve as valuable lead structures，and they are frequently needed as starting materials or as intermediates for important synthetic products.Table 1 gives an overview of the different methods for obtaining pharmaceutical agents.Table 1 Possibilities for the preparation of drugsMethods Examples1. Total synthesis -over 75 % of all pharmaceutical agents (synthetics)2. Isolation from natural sources (natural products):2.1 Plants -alkaloids;enzymes;heart glycosides;polysaccharides;tocopherol;steroid precursors (diosgenin, sitosterin);citral (intermediate product forvitamins A, E，and K)2.2 Animal organs一enzymes;peptide hormones;cholic acid from gall; insulin) from thepancreas;sera and vaccines2. 3 Other sources一cholesterol from wool oils;L-amino acids from keratin and gelatinehydrolysates3. Fermentation一antibiotics;L-amino acids;dextran; targeted modifications on steroids，e.g. 11-hydroxylation; also insulin, interferon, antibodies, peptidehormones，enzymes，vaccines4. Partial synthetic modification of natural products (semisynthetic agents):一alkaloid compounds;semisynthetic /3-lactam antibiotics;steroids;human insulinSeveral therapeutically significant natural products which were originally obtained from natural sources are today more effectively -i. e. more economically -prepared.. by total synthesis. Such examples include L-amino acids，Chloramphenicol，Caffeine, Dopamine，Epinephrine，Levodopa, peptide hormones，Prostaglandins，D-Penicillamine，Vincamine，and practically all vitamins.Over the last few years fermentation - i. e. microbiological processes has become extremely important. Through modern technology and results from genetic selection leading to the creation of high performance mutants of microorganisms，fermentation has already become the method of choice for a wide range of substances. Both Eukaryonts (yeasts and moulds)and Prokaryonts(single bacterial cells，and actinomycetes)are used microorganisms. The following product types can be obtained:1. cell material (single cell protein)，2. enzymes，3. primary degradation products (primary metabolites)，4. secondary degradation products (secondary metabolites).Disregarding the production of dextran from the mucous membranes of certain microorganisms，e. g. Leuconostoc mesenteroides，classes 2 and 3 are the relevant ones for the preparation of drugs. Dextran itself，with a molecular weight of 50,000 ~ 100,000，is used as a blood plasma substitute. Among the primary metabolites the L-amino acids from mutants of Corynebacterium glutamicum and Brevibacterium flavum are especially interesting. From these organisms some 350，000 tones of monosodium L-glutamate (food additive)and some 70，000 tones of L-lysine(supplement for vegetable proteins)are produced. Further important primary metabolites are the purina nucleotides，organic acids，lactic acid，citric acid，and vitamins，for example vitamin B,2 from Propionibacterium shermanii.Among the secondary metabolites the antibiotics must be mentioned first. The following five groups represent a yearly worldwide value of US-$17 billion:penicillins ( Penicillium chrysogenum )，cephalosporins ( Cephalosporium acremonium )，tetracyclines ( Streptomyces aureofaciens )，erythromycins ( Streptomyces erythreus )，aminoglycosides (e. g. streptomycin from Streptomyces griseus).About 5000 antibiotics have already been isolated from microorganisms，but of these only somewhat fewer than 100 are in therapeutic use. It must be remembered，however，that many derivatives have been modified by partial synthesis for therapeutic use;some 50，000 agents have been semisynthetically obtained from户lactams alone in the last decade. Fermentations are carried out in stainless steel fermentors with volumes up to 400 m3. To avoid contamination of the microorganisms with phages etc. the whole process has to be performed under sterile conditions. Since the more important fermentations occur exclusively under aerobic conditions a good supply of oxygen or air(sterile)is needed. Carbon dioxide sources include carbohydrates，e. g. molasses，saccharides，and glucose. Additionally the microorganisms must be supplied in the growth medium with nitrogen-containing compounds such as ammonium sulfate，ammonia，or urea，as well as with inorganic phosphates. Furthermore，constant optimal pH and temperature are required. In the case of penicillin G，the fermentation is finished after 200 hours，and the cell mass is separated by filtration. The desired active agents are isolated from the filtrate by absorption or extraction processes. The cell mass，if not the desired product，can be further used as an animal feedstuff owing to its high protein content.By modern recombinant techniques microorganisms have been obtained which also allow production of peptides which were not encoded in the original genes. Modified E. coli bacteria make it thus possible to produce A- and B- chains of human insulin or proinsulin analogs. The disulfide bridges are formed selectively after isolation，and the final purification is effected by chromatographic procedures. In this way human insulin is obtained totally independently from any pancreatic material taken from animals.Other important peptides，hormones，and enzymes，such as human growth hormone (HGH)，neuroactive peptides，somatostatin，interferons，tissue plasminogen activator (TPA)，lymphokines，calcium regulators like calmodulin，protein vaccines，as well as monoclonal antibodies used as diagnostics，are synthesized in this way.The enzymes or enzymatic systems which are present in a single microorganism can be used for directed stereospecific and regiospecific chemical reactions. This principle is especially useful in steroid chemistry. Here we may refer only to the microbiological 11-a- hydro xylation of progesterone to 11-a-hydroxyprogesterone，a key product used in the synthesis of cortisone. Isolated enzymes are important today not only because of the technical importance of the enzymatic saccharification of starch，and the isomerization of glucose to fructose，They are also significant in the countless test procedures used in diagnosing illness，and in enzymatic analysis which is used in the monitoring of therapy.A number of enzymes are themselves used as active ingredients. Thus preparations containing proteases (e. g. chymotrypsin，pepsin，and trypsin)，amylases and lipases，mostly in combination with synthetic antacids，promote digestion. Streptokinase and urokinase are important in thrombolytics，and asparaginase is used as a cytostatic agent in the treatment of leukemia.Finally mention must be made of the important use of enzymes as `biocatalyst s’in chemical reactions where their stereospecificity and selectivity can be used. Known examples are the enzymatic cleavage of racemates of N-acetyl-D，L-amino acids to give L-amino acids，the production of 8-aminopenicillanic acid from benzylpenicillin by means of penicillinamidase and the aspartase-catalysed stereospecific addition of ammonia to fumaric acid in order to produce L-aspartic acid.In these applications the enzymes can be used in immobilized forms-somehow bound to carriers - and so used as heterogeneous catalysts. This is advantageous because they can then easily be separated from the reaction medium and recycled for further use.Another important process depending on the specific action of proteases is applied for the production of semisynthetic human insulin. This starts with pig insulin in which the alanine in the 30-position of the B-chain is replaced by a threonine tert-butyl ester by the selective action of trypsin. The insulin ester is separated，hydrolyzed to human insulin and finally purified by chromatographic procedures.Sources for enzymes include not only microorganisms but also vegetable and animal materials.In Table 1 it was already shown that over 75%of all pharmaceutical agents are obtained by total synthesis. Thereforeknowledge of the synthetic routes is useful. Understanding also makes it possible to recognize contamination .of the agents by intermediates and by- products. For the reason of effective quality control the registration authorities in many countries demand as essentials for registration a thorough documentation on the production process. Knowledge of drug syntheses provides the R&D chemist with valuable stimulation as well.There are neither preferred structural classes for all pharmaceutically active compounds nor preferred reaction types. This implies that practically the whole field of organic and in part also organometallic chemistry is covered. Nevertheless，a larger number of starting materials and intermediates are more frequently used，and so it is useful to know the possibilities for their preparation from primary chemicals. For this reason it is appropriate somewhere in this book to illustrate a tree of especially important intermediates. These latter intermediates are the key compounds used in synthetic processes leading to an enormous number of agents. For the most part chemicals are involved which are produced in large amounts. In a similar way this is also true for the intermediates based on the industrial aromatic compounds toluene，phenol and chlorobenzene. Further key compounds may be shown in a table which can be useful in tracing cross-relationships in syntheses.fIn addition to the actual starting materials and intermediates solvents are required both as a reaction medium and ,for purification via recrystallization. Frequently used solvents are methanol，ethanol，isopropanol，butanol，acetone，ethyl acetate，benzene，toluene and xylene. To a lesser extent diethyl ether，tetrahydrofuran，glycol ethers，dimethylformamide (DMF) and dimethyl sulphoxide (DMSO) are used in special reactions.Reagents used in larger amounts are not only acids (hydrochloric acid，sulfuric acid，nitric acid，acetic acid) but also inorganic and organic bases (sodium hydroxide，potassium hydroxide，potassium carbonate，sodium bicarbonate，ammonia，triethylamine，pyridine). Further auxiliary chemicals include active charcoal and catalysts. All of these supplementary chemicals (like the intermediates) can be a source of impurities in the final product.In 1969 the WHO published a treatise on `Safeguarding Quality in Drugs'.Appendix 2 is concerned with the `Proper Practice for Reparation and Safeguarding Quality in Drugs' (WHO Technical Report No. 418，1969，Appendix 2;No. 567，1975，Appendix 1A). This has in the meantime become known as `Good Manufacturing Practices' or GMP rules，and these should now be obeyed in drug production. They form the basis for mutual recognition of quality certificates relating to the production of pharmaceuticals and for inspections of the production. facilities.For a long time the US drug authority，the Food and Drug Administration (FDA)，has issued regulations for the preparation of drugs analogous to the WHO rules，and it applies these strictly. Exports of drugs to the USA，like those of finished products，require regular inspection of the production facilities by the FDA. 5It may merely be noted here that such careful control applies not only to the products，but also to the raw materials (control of starting Materials)，and also to the intermediates. Clearly. the technical and hygienic equipment of the production and the storage areas have to fulfill set conditions.Since only a few compounds，such as acetylsalicylic acid，paracetamol and vitamins，are prepared in large amounts，most of the actual production takes place in multi-purpose (multi-product) facilities. .Special care has to be taken to avoid cross-contamination by other products what can be effected by good cleansing of used apparatus. A careful description and definition of all stored intermediates and products is needed.Selected -from H. J. Roth and A. Kleemann, Pharmaceutical Chemistry, Vol. 1，Drug Synthesis,Ellis Horwood Limited，England, 1988.Unit 5 Drug Development (I)1. IntroductionDrug Development is a very complex process requiring a great deal ofcoordination and communication between a wide range of different functionalgroups. It is expensive，particularly in the later phases of clinical development，where studies involve hundreds of patients. It is currently estimated that thedevelopment of a new drug costs about$230 million(1987 dollars)and takessomewhere between 7 and 10 years from initiation of preclinical development tofirst marketing (excluding regulatory delays). Drug development is a high-riskbusiness;although the rate is increasing，only about ONE out of every TEN newchemical entities studied in human beings for the first time will ever become a product. As a drug candidate progresses through development the risks of failure decrease as ‘hurdles’are overco me along the way. Typical reasons for failure include unacceptable toxicity，lack of efficacy，or inability to provide advantages over competitive products(Fig. 1).Attrition Rate of New Chemical Entities(NCE's) entering development. On averageonly about I in 400^1000 compoundssynthesized enters development.Reasons for termination of development of NCE's(excluding anti-infectives)1:Lack of efficacy2: Pharmacokinetics3: Animal toxicity4: Miscellaneous5: Adverse effects in man6: Commercial reasonsFig. 1 Attrition rates and reasons for terminations2. Planning for developmentAssessment of whether a drug candidate is likely to provide competitive advantages highlights the need first to have in place a set of product `goals' or target product profile. Particular attention should be paid to the differentiation from competitors. This is becoming 55 more and more critical with the increasing emphasis on limited formularies，healthcare costs，and pharmacoeconomics (discussed later in the chapter).A target profile will define the indication(s) that a drug candidate will be developed for，along with goals such as once a day dosing，faster onset of action，better side effect profile than a major competitor. The target profile can be refined and revised as a drug candidate moves through development and new data on the drug candidate or competitors become available. The logical next steps are to define the development strategy，for example，which indications to develop first，which countries to aim to market the drug in and then to define the core clinical studies necessary to achieve regulatory approval and commercial success.This chapter will describe the main activities required for successful development of a new drug. All these activities，many of which are interdependent，need to be carefully planned and co-ordinate. Speed to market with collection of high quality data is critical for success. The path of activities which determine the time it will take to get to registration is called，in project management terms，the critical path. It is vital to plan and prepare before studies begin and to monitor and manage problems so as to ensure that the critical path remains on schedule. With increased economic pressures and competitive intensity it is important for companies to explore ways to shorten this critical path. Running activities in parallel，or overlapping studies which would usually run sequentially，often involves an increase in risk but the dividends in time-saving can make such strategies worthwhile.The critical path for development of a new drug generally runs through the initial synthesis of compound，subacute toxicology studies，and then the clinical program. A chart showing the critical path activities for a typical drug candidate is shown in Fig. 2.Chemistry chemical Synthesis Route selection Pilot plant,scale up and stability testing Manufacturing plant productionToxicology Acute&subacute toxicology Long term and repro-toxicologyClinical Phase I Phase ll Phase lll Analysis data and report Phase lV ReviewRegulatory Submission and updating of clinical trial application prepare submit AuthorityMAA/NDA Regulatory ApprovalPost marketing SurverillancePharmaceuticsDevelopment and stability testing Prepare labellingDrug metabolismand pharmacokinetics Animal ADME* Healthy humans Human patientsActivities likely to be on the critical path are shown in bold* Absorption , Distribution , Metabolism , ExcretionFig. 2 The major processes in new drug developmentThe following sections highlight the objectives and activities of drug development work.Activities within each technical discipline are described broadly in chronological order.At any one time，work in all these disciplines may be proceeding in parallel. The timing and outcome of much of the work has direct impact on work in other disciplines. The major phases of drug development are Preclinical ( studies required before the compound can be dosed in humans)，Phase I (clinical studies usually in healthy human volunteers ) Phase Ⅱ( initial efficacy and safety and dose finding studies in patients)，and Phase Ⅲ(studies in several hundred patients). There then follows assembly of a marketing application dossier for subsequent review by country regulatory authorities.3. Chemical developmentRapid development of a drug candidate is dependent on the availability of sufficient quantity of the compound. The purity of compound needs to reach certain standards in order for it to be used in safety (toxicology)，pharmaceutical，and clinical studies. Initially，chemists will work on a small to medium scale to investigate production of the compound by several different methods so as to identify the optimum route for synthesizing the compound. ‘Optimum’here may mean a combination of several factors，for example，most efficient，cheapest safe，or that producing minimal waste. Analysis of the final product as well as intermediates and impurities plays a key role in identifying the best method of synthesis. Development and validation of analytical methods are necessary to support process development and guarantee the purity of the drug substance.In some cases levels of impurities may be unacceptably high and either improved purification procedures will need to be developed or the synthetic process may require significant alterations. The main aim is to ensure that the composition of compound is understood and that ultimately the material that is prepared is as pure as possible.As a drug candidate progresses through development，larger and larger amounts of compound are required. The amount of material required for different tests will often depend on the actual potency and dosage form of the compound.A pilot plant can be regarded as a mini-manufacturing set-up. Before transferring to a pilot plant，extensive evaluation and testing of the chemical synthesis is undertaken to ensure that any changes and hazards are minimized. Procedures are optimized，particular attention being paid to developing environmentally acceptable ways of disposing of waste products. Commercial production of bulk drug substance for production of a drug，once approved and marketed，will likely take place on a larger scale or at a registered manufacturing plant.4. Formulation developmentThe dosage form of a drug is the form by which it is administered to the patient. There are a vast array of possible dosage forms ranging from transdermal patches to inhalers to intranasal medicines. The more common dosage forms include oral tablets or capsules，oral liquids，topical ointments or creams，and injectables. The dosage form or forms chosen for a particular drug candidate will be defined in the target profile.Sometimes a more simple dosage form，for example an oral solution，is chosen for early 57 clinical studies in human beings. This may save time and upfront costs at an early，high-risk stage of the drug development process. Later clinical studies would use the expected marketed dosage form.Whatever the dosage form，the combination of drug and other materials which constitute it must fulfil certain criteria. One of the most important is that of adequate stability. That means a predetermined potency level must remain after，for example，two or three years. The stability data generated on a dosage form will determine its shelf-life and recommended storage conditions. Early in development the shelf-life may be limited to several months. This will not be a problem provided it is sufficient to cover use of the drug over the duration of the clinical study or studies.5. PharmacologyBefore a drug candidate is given to man，its pharmacological effects on major systems are often investigated in a number of species. The body systems studied include cardiovascular，respiratory，and nervous systems;the effects on gross behavior can also be studied.Experiments are sometimes conducted to see whether the drug candidate interferes with the actions of other medicines which，because of their specific effects or because of their common use，are likely to be taken concurrently with the drug candidate. Any synergism or antagonism of drug effects should be investigated，and any necessary warning issuedto clinical investigators.(It may be judged necessary to investigate such effects further in clinical studies，and any potential or proven drug interactions are likely to be noted in the product labeling for the drug.)It may also be appropriate to identify a substance for possible use in the management of overdosage，particularly if the therapeutic margin of the drug candidate is small.6. Safety evaluationThe objective of animal toxicology testing，carried out prior to the administration of a drug to man，is to reject compounds of unacceptable toxicity and to identify potential target organs and timings for adverse effects of the drug. This means that in early human studies these organs and tissues can be monitored with particular attention. It is important to establish whether toxic effects are reversible or irreversible，whether they can be prevented and，if possible，the mechanism of the toxicological effects. It is also important to interrelate drug response to blood levels in humans and blood levels in various animal species.The toxicological studies required for the evaluation of a drug candidate in man will be relevant to its proposed clinical use in terms of route of administration and duration of treatment of the clinical studies. The size and frequency of the doses and the duration of the toxicology studies are major determinants of permissible tests in man. Countries，including UK，USA，Australia，and Nordic countries，have regulatory guidelines which relate the duration of treatment allowed in man to the length of toxicity studies required in two species. Points from the guidelines are referenced in the subsequent sections.58 Initially，the pharmacological effects of increasing doses of the test substances are established in acute toxicity studies in small numbers of animals，generally using two routes of administration (one being that used in man). Results provide a guide to the maximum tolerated doses in subsequent chronic. toxicity tests，aid selection of dose levels，and identify target organs.The main aim of the subsequent sub-acute toxicity tests is to determine whether or not the drug candidate is adequately tolerated after administration to animals for a prolonged period as a guide to possible adverse reactions in man. Two to four week (daily dosing) studies are required，using the same route of administration as in man，in two species (one non-rodent)prior to administration of the compound to man. Three dose levels are usually necessary:the low daily dose should be a low multiple of the expected therapeutic dose，and the highest dose should demonstrate some toxicity.A general guide for the evaluation of new chemical entities would be that toxicology studies of a minimum duration of14 days are required to support single-dose exposure of a new drug candidate in normal volunteers in Phase 1. Toxicology studies of 30 days duration are required to support clinical studies of 7 to 10 days duration. Clinical studies of greater than 7 to 10 days up to 30 days duration require the support of at least 90 days toxicology studies. These requirements illustrate the need to plan ahead in drug development. The duration and approximate timings for future clinical trials need to be considered well in advance in order to schedule and conduct the appropriate toxicology studies to support the clinical program and avoid any delays.Two types of safety test are used to detect the ability of the drug candidate to produce tumours in man. The first are short-term in vitro genotoxicity tests，for example bacterial tests. The second are long-term animal carcinogenicity studies which are conducted in mice and rats;their length of often 2 years covers a large part of the lifespan of the animal. Mice and rats are used because of their relatively short life span，small size，and ready availability. Also，knowledge，which has accumulated concerning spontaneous diseases and tumours②in particular strains of these species，helps greatly in the interpretation of‘results.Long-term toxicology and carcinogenicity studies are conducted in order to obtain approval to test and finally to market a product for chronic administration to man. These studies may need to start during the late preclinical/ early clinical phase in order to `support' the subsequent clinical program. Long-term toxicity studies will normally include toxicity studies of six and twelve months duration in two species (one non-rodent).Any toxicity previously detected may be investigated more closely，for example extra enzymes looked at in blood samples.Reproductive toxicology is that part of toxicology dealing with the effect of compounds on reproduction-fertility，foetal abnormalities，post-natal development. Prior to clinical studies in women of child-bearing age，regulatory authorities require teratology data from two species (normally rat and rabbit)as well as clinical data from male volunteers. No reproductive data are required prior to clinical studies in male subjects. The effects of 59 compounds on reproduction differ with the period of the reproductive cycle in which exposure takes place and studies are designed to look at thesephases. Teratology`'' studies are designed to detect foetal abnormalities，fertility studies to investigate the compounds' effect on reproductive performance，And peri- and post-natal studies to study the development of pups.Unit 6 Isolation of Caffeine from TeaIn this experiment，Caffeine will be isolated from tea leaves. The major problem of the isolation is that caffeine does not occur alone in tea leaves，but is accompanied by other natural substances from which it must be separated. The major component of tea leaves is cellulose，which is the major structural material of all plant cells. Cellulose is a polymer of glucose. Since cellulose is virtually insoluble in water，it presents no problems in the isolation procedure. Caffeine，on the other hand，is water soluble and is one of the major substances extracted into the solution called "tea.”Caffeine comprises as much as 5 percent by weight of the leaf material in tea plants. Tannins also dissolve in the hot water used to extract tea leaves. The term tannin does not refer to a single homogeneous compound，or even to substances which have similar chemical structure. It refers to a class of compounds which have certain properties in common. Tannins are phenolic compounds having molecular weights between 500 and 3000. They a re widely used to "tan”leather. They precipitate alkaloids'z and proteins from aqueous solutions. Tannins are usually divided into two classes: those which can be hydrolyzed and those which cannot. Tannins of the first type which are found in tea generally yield glucose and gallic acid when they are hydrolyzed. These tannins are esters of gallic acid and glucose. They represent structures in which some of the hydroxyl groups in glucose have been esterified by digalloyl groups. The non-hydrolyzable tannins found in tea are condensation polymers of catechin. These polymers are not uniform in structure，but catechin molecules are usually linked together at ring positions 4 and 8.When tannins are extracted into hot water，the hydrolyzable ones are partially hydrolyzed，meaning that free gallic acid is also found in tea. The tannins，by virtue of their phenolic groups，and gallic acid by virtue of its carboxyl groups，are both acidic. If calcium carbonate，a base，is added to tea water，the calcium salts of these acids are formed. Caffeine can be extracted from the basic tea solution with chloroform，but the calcium salts of gallic acid and the tannins are not chloroform soluble and remain behind in the aqueous solution.The brown color of a tea solution is due to flavonoid pigments and chlorophylls，as well as their respective oxidation products. Although chlorophylls are somewhat chloroform soluble，most of the other substances in tea are not. Thus，the chloroform extraction of the basic tea solution removes nearly pure caffeine. The chloroform is easily removed by distillation(by 61'C)to leave the crude caffeine. The caffeine may be purified by recrystallization or by sublimation.68Catechin Gallic AcidIn a second part of this experiment，Caffeine will be converted to a derivative. A derivative of a compound is a second compound，of known melting point，formed from the original compound by a simple chemical reaction. In trying to make a positive identification of an organic compound，it is often customary to convert it into a derivative. If the first compound，Caffeine in this case，and its derivative both have melting points which match those reported in the chemical literature (e.g.，a handbook)，it is assumed that there is no coincidence and that the identity of the first compound，Caffeine，has been definitely established.Caffeine is a base and will react with an acid to give a salt. Using salicylic acid，a derivative salt of Caffeine，Caffeine salicylate，will be made in order to establish the identity of the Caffeine isolated from tea leaves.Special Instructions Be careful when handling chloroform. It is a toxic solvent，and you should not breathe it excessively or spill it on yourself. When discarding spent tea leaves，do not put them in the sink because they will clog the drain. Dispose of them in a waste container.Procedure Place 25g of dry tea leaves，25g of calcium carbonate powder，and 250ml of water in a 500ml three neck round bottom flask equipped with a condenser for reflux. Stopper the unused openings in the flask and heat the mixture under reflux for about 20 minutes. Use a Bunsen burner to heat. While the solution is still hot，filter it by gravity through a fluted filter using a fast filter paper such as E&D No. 617 or S&S No. 595. You may need to change the filter paper if it clogs.Cool the filtrate (filtered liquid)to room temperature and，using a separatory funnel，extract it twice with 25ml portions of chloroform. Combine the two portions of chloroform in a 100ml round bottom flask，Assemble an apparatus for simple distillation and remove the chloroform by distillation. Use a steam bath to heat. The residue in the distillation flask contains the caffeine and is purified as described below (crystallization). Save the chloroform that was distilled. You。

尼龙的主要成分

尼龙的主要成分尼龙，作为一种重要的合成纤维材料，具有广泛的应用领域和出色的性能特点。

它的主要成分是聚酰胺（Polyamide），经由特定的聚合反应所形成。

在本文中，我将深入探讨尼龙的主要成分，包括聚酰胺的结构、特性以及其在尼龙中的应用。

1. 聚酰胺（Polyamide）的结构和特性：聚酰胺是由含有酰基和胺基的官能团组成的聚合物。

其结构中的酰基和胺基通过酰胺键（Amide bond）相连形成聚酰胺链。

聚酰胺的重复单元中含有酸基和胺基，可以通过不同的酸基和胺基组合形成不同类型的聚酰胺。

聚酰胺具有以下主要特性：- 强度高：聚酰胺拥有出色的强度和韧性，使其在纺织、工程塑料等领域得到广泛应用。

- 耐磨性好：聚酰胺具有较好的耐磨性能，使其在制造耐磨部件、纺织品等方面表现出色。

- 耐化学性强：聚酰胺对一些常见的化学品和溶剂有较好的抗腐蚀能力，使其在化工和医疗领域得到广泛应用。

- 热稳定性好：聚酰胺能够在高温环境下保持较好的稳定性，使其在高温工艺和高温环境中发挥重要作用。

2. 聚酰胺在尼龙中的应用：尼龙是聚酰胺类合成纤维的一种，通过合成聚酰胺链来制备。

尼龙具有许多优秀的性能和应用特点，拥有广泛的应用领域。

2.1 尼龙的纺织应用：尼龙纤维由聚酰胺链组成，具有出色的强度、耐磨性和耐腐蚀性，因此在纺织行业中得到广泛应用。

尼龙纤维可制成各种类型的面料，包括尼龙绸、尼龙绒等，用于制作服装、袜子、家居纺织品等。

尼龙纤维的特性使得纺织品具有良好的强度和柔软性，同时具备吸湿性和透湿性，使其舒适适应各种气候条件。

2.2 尼龙的工程塑料应用：尼龙作为一种工程塑料，被广泛应用于制造各种零件和组件。

其高强度、耐磨性和耐化学性使得尼龙在汽车、航空航天、机械制造等领域中得到广泛应用。

尼龙可以用于制造汽车发动机零部件、制动系统组件、齿轮、轴承等。

在航空航天领域，尼龙被用于制造飞机构件、航天器零件等。

尼龙的轻质和高强度使其成为替代金属材料的理想选择。

海蜗牛卵胶囊蛋白自组装

b c
Energy Research Institute at Nanyang Technological University, NTU, 637141, Singapore
d
Institute of Chemical and Engineering Sciences (ICES), Agency for Science, Technology, and Research (A*Star), 1 Pesek Road, Jurong Island, 627833, Singapore
Published on 13 February 2015. Downloaded by Beijing University of Chemical Technology on 14/08/2015 06:23:15.
Received 29th August 2014 Accepted 10th February 2015 DOI: 10.1039/c4tb01434k /MaterialsB
Introduction
Molecular biomimicry of natural-based biopolymers has attracted considerable interest in the past decade. Biological extracellular materials predominantly made of proteins are particularly useful model systems because of our ability to precisely recapitulate their complex chemistry through recombinant DNA and protein engineering.1,2 Hence, these articial protein-based systems have received wide interest

开启片剂完整性的窗户(中英文对照)

开启片剂完整性的窗户日本东芝公司，剑桥大学摘要：由日本东芝公司和剑桥大学合作成立的公司向《医药技术》解释了FDA支持的技术如何在不损坏片剂的情况下测定其完整性。

太赫脉冲成像的一个应用是检查肠溶制剂的完整性，以确保它们在到达肠溶之前不会溶解。

关键词：片剂完整性，太赫脉冲成像。

能够检测片剂的结构完整性和化学成分而无需将它们打碎的一种技术，已经通过了概念验证阶段，正在进行法规申请。

由英国私募Teraview公司研发并且以太赫光（介于无线电波和光波之间）为基础。

该成像技术为配方研发和质量控制中的湿溶出试验提供了一个更好的选择。

该技术还可以缩短新产品的研发时间，并且根据厂商的情况，随时间推移甚至可能发展成为一个用于制药生产线的实时片剂检测系统。

TPI技术通过发射太赫射线绘制出片剂和涂层厚度的三维差异图谱，在有结构或化学变化时太赫射线被反射回。

反射脉冲的时间延迟累加成该片剂的三维图像。

该系统使用太赫发射极，采用一个机器臂捡起片剂并且使其通过太赫光束，用一个扫描仪收集反射光并且建成三维图像(见图)。

技术研发太赫技术发源于二十世纪九十年代中期13本东芝公司位于英国的东芝欧洲研究中心，该中心与剑桥大学的物理学系有着密切的联系。

日本东芝公司当时正在研究新一代的半导体，研究的副产品是发现了这些半导体实际上是太赫光非常好的发射源和检测器。

二十世纪九十年代后期，日本东芝公司授权研究小组寻求该技术可能的应用，包括成像和化学传感光谱学，并与葛兰素史克和辉瑞以及其它公司建立了关系，以探讨其在制药业的应用。

虽然早期的结果表明该技术有前景，但日本东芝公司却不愿深入研究下去，原因是此应用与日本东芝公司在消费电子行业的任何业务兴趣都没有交叉。

这一决定的结果是研究中心的首席执行官DonArnone和剑桥桥大学物理学系的教授Michael Pepper先生于2001年成立了Teraview公司一作为研究中心的子公司。

TPI imaga 2000是第一个商品化太赫成像系统，该系统经优化用于成品片剂及其核心完整性和性能的无破坏检测。

药物过敏反应国际共识

P O S I T I O N P A P E RInternational Consensus on drug allergyP.Demoly1,N.F.Adkinson2,K.Brockow3,M.Castells4,A.M.Chiriac1,P.A.Greenberger5,D.A.Khan6, ng7,H.-S.Park8,W.Pichler9,M.Sanchez-Borges10,T.Shiohara11&B.Y.-H.Thong121D e partement de Pneumologie et Addictologie,H^o pital Arnaud de Villeneuve,University Hospital of Montpellier,France and SorbonneUniversit e s,Paris,France;2Division of Allergy and Clinical Immunology,The Johns Hopkins Asthma and Allergy Center,The Hopkins Bayview Medical Campus,Baltimore,MD,USA;3Department of Dermatology and Allergology Biederstein,Technische Universit€a t M€u nchen,Munich, Germany;4Division of Rheumatology,Allergy and Immunology,Department of Medicine,Brigham and Women’s Hospital,Boston,MA;5Division of Allergy-Immunology,Northwestern University Feinberg School of Medicine,Chicago,IL;6Division of Allergy&Immunology,University of Texas Southwestern Medical Center,Dallas,TX;7Department of Allergy/Immunology,Respiratory Institute,Cleveland Clinic Foundation, Cleveland,OH,USA;8Department of Allergy and Clinical Immunology,Ajou University School of Medicine,Suwon,Korea;9Division of Allergology,Department of Rheumatology and Allergology/Clinical Immunology,Inselspital,University of Bern,Bern,Switzerland;10Allergy and Clinical Immunology Department,Centro Medico Docente La Trinidad,Caracas,Venezuela;11Department of Dermatology,Kyorin University School of Medicine,Tokyo,Japan;12Department of Rheumatology,Allergy and Immunology,Tan Tock Seng Hospital,SingaporeTo cite this article:Demoly P,Adkinson NF,Brockow K,Castells M,Chiriac AM,Greenberger PA,Khan DA,Lang DM,Park H-S,Pichler W,Sanchez-Borges M, Shiohara T,Thong BY-H.International Consensus on drug allergy.Allergy2014;69:420–437.Keywordsdrug allergy work-up;drug hypersensitivity reaction;recommendation.CorrespondencePascal Demoly,D e partement de Pneumologie et Addictologie,H^o pital Arnaud de Villeneuve, University Hospital of Montpellier,France and Sorbonne Universit e s,UPMC Paris06,UMR-S1136,IPLESP,Equipe EPAR,75013, Paris,France.Tel.:0033467336107Fax:0033467042708E-mail:pascal.demoly@inserm.frDraft reviewed by:Apter AJ(USA);Asero R (Italy);Barbaud A(France);Bavbek S(Turkey); Bircher AJ(Switzerland);Bonadonna P(Italy); Bousquet PJ(France);Caubet JC(Switzerland); Celik G(Turkey);Cernadas JR(Portugal); Commins SP(USA);Descamps V(France);Drouet M(France);Ebo DG(Belgium);Garvey LH (Denmark);Gomes E(Portugal);Grendelmeier P (Switzerland);Terreehorst I(the Netherlands); Jensen-Jarolim E(Austria);Kanny G(France); Kano Y(Japan);Kidon MI(Israel);Laroche D (France);Macy E(USA);Mertes PM(France); Mirakian R(UK);Musette P(France);Naisbitt DJ (UK);Nasser SM(UK);Nicolas JF(France); Nizankowska-Mogilnicka E(Poland);Pagani M (Italy);Park BK(UK);Ponvert C(France);Romano A(Italy);Roujeau JC(France);Sanz ML(Spain); Schiavino D(Italy);Tanno LK(Brazil);Torres MJ (Spain);Valeyrie-Allanore L(France);Ventura M (Italy);Volcheck GW(USA);Volkenstein P (France);Vultaggio A(Italy);Wallace DV(USA). Accepted for publication18November2013DOI:10.1111/all.12350Edited by:Hans-Uwe Simon AbstractWhen drug reactions resembling allergy occur,they are called drug hypersensitiv-ity reactions(DHRs)before showing the evidence of either drug-speciﬁc antibod-ies or T cells.DHRs may be allergic or nonallergic in nature,with drug allergies being immunologically mediated DHRs.These reactions are typically unpredict-able.They can be life-threatening,may require or prolong hospitalization,and may necessitate changes in subsequent therapy.Both underdiagnosis(due to under-reporting)and overdiagnosis(due to an overuse of the term‘allergy’)are common.A deﬁnitive diagnosis of such reactions is required in order to institute adequate treatment options and proper preventive measures.Misclassiﬁcation based solely on the DHR history without further testing may affect treatment options,result in adverse consequences,and lead to the use of more-expensive or less-effective drugs,in contrast to patients who had undergone a complete drug allergy workup.Several guidelines and/or consensus documents on general or spe-ciﬁc drug class-induced DHRs are available to support the medical decision pro-cess.The use of standardized systematic approaches for the diagnosis and management of DHRs carries the potential to improve outcomes and should thus be disseminated and implemented.Consequently,the International Collaboration in Asthma,Allergy and Immunology(iCAALL),formed by the European Acade-my of Allergy and Clinical Immunology(EAACI),the American Academy of Allergy,Asthma and Immunology(AAAAI),the American College of Allergy, Asthma and Immunology(ACAAI),and the World Allergy Organization (WAO),has decided to issue an International CONsensus(ICON)on drug allergy.The purpose of this document is to highlight the key messages that are common to many of the existing guidelines,while critically reviewing and commenting on any differences and deﬁciencies of evidence,thus providing a comprehensive reference document for the diagnosis and management of DHRs.Drugs can induce several different types of immunological reactions that,together with nonallergic drug hypersensitivity reactions(DHRs),comprise15%of all adverse drug reac-tions(1).Nonallergic DHRs resemble allergy,but without any proven immunological mechanism.Drug hypersensitivity reactions are of signiﬁcant concern for clinicians and patients and are also a signiﬁcant cause of the postmarketing withdrawal of drugs(2).Even though urti-carial and maculopapular eruptions are the most frequent manifestations,there are many other clinical presentations (1).DHRs affect more than7%of the general population and therefore represent an important public health problem (3).Both underdiagnosis(due to under-reporting(3,4))and overdiagnosis(due to an overuse of the term‘allergy’,for example,in the presence of symptoms due to co-existing fac-tors such as infections(3,5))are potential problems.Misclas-siﬁcation based on the DHR history alone may limit therapeutic options and can lead to the use of more-expen-sive and potentially less-effective drugs(6).Moreover,one drug allergy may lead to the misconception that the patient is allergic to all drugs.Few guidelines and/or consensus documents are available to support medical decision making on all aspects of DHR.These documents vary in scope and methodology:They are national (6–10),regional,or international(11–22);concern one speciﬁc drug class(7,8,14–16,18,20,21,23);focus speciﬁcally on evaluation tools/management(11–13,17,19,23);or are more general(6,8,24,25).Although there is no doubt that the use of common systematic approaches for the diagnosis and man-agement of DHRs can considerably improve outcomes,world-wide dissemination and implementation remain major challenges.For these reasons,the International Collaboration in Asthma,Allergy and Immunology(iCAALL)(26),recently formed by the European Academy of Allergy and Clinical Immunology(EAACI),the American Academy of Allergy, Asthma and Immunology(AAAAI),the American College of Allergy,Asthma and Immunology(ACAAI),and the World Allergy Organization(WAO),has decided to proceed with the compilation of an International CONsensus(ICON)on drug allergy.The purpose of this document is to highlight the key messages that are common to the existing guidelines,while crit-ically reviewing and commenting on any differences,thus pro-viding a comprehensive reference to be disseminated more widely.As for the ICON on pediatric asthma(27),unmet needs,research,and guideline update recommendations are generated.MethodologyA working committee was formed and approved by the cur-rent board of iCAALL and the participating organizations. The criteria used for the formation of the committee were as follows:regional representation,relevance to theﬁeld,and previous participation in drug allergy guidelines.The mem-bers of the committee proposed relevant documents for appraisal.These included(i)the AAAAI/ACAAI/Joint Council of Allergy,Asthma and Immunology drug allergy updated practice parameters(6,7),(ii)the WAO drug allergy initiatives(24,25),(iii)the British Society of Allergy and Clinical Immunology(BSACI)guidelines(8,9),and(iv)the many task force reports and consensus documents of the EAACI Drug Allergy Interest Group(DAIG)as well as its core group,the European Network of Drug Allergy(ENDA) (11–21,23).Each member was responsible for the prepara-tion of text and relevant tables comparing the included docu-ments in a speciﬁc domain.A draft was subsequently compiled and circulated(in September2012)among the authors for comments and corrections.The revised document was then sent(in April2013)to an independent reviewing committee,selected on the basis of their publications over the past5years in top peer-reviewed journals asﬁrst/last authors.Their comments were taken into account in theﬁnal draft,which was then approved by the governing boards of the participating organizations.Recommendations were extrapolated from the reference documents and presented using levels of Evidence A–D(28)(Table1).Deﬁnition and classiﬁcations of drug hypersensitivity reactionsDeﬁnitionDrug hypersensitivity reactions(DHRs)are the adverse effects of pharmaceutical formulations(including active drugs and excipients)that clinically resemble allergy(29) (Box1).DHRs belong to type B adverse drug reactions, which are deﬁned by the World Health Organization as the dose-independent,unpredictable,noxious,and unintended response to a drug taken at a dose normally used in humans(30,31).A-type reactions,including overdoses and pharmacological reactions,are dose dependent and predict-able.However,some dose dependence has been shown repeatedly in DHRs(e.g.,for nonsteroidal anti-inﬂamma-tory drugs(NSAIDs),antiepileptic drugs)and some areAbbreviationsAAAAI,American Academy of Allergy,Asthma and Immunology;ACAAI,American College of Allergy,Asthma and Immunology;AGEP,acute generalized exanthematous pustulosis;AIDS,acquired immunodeﬁciency syndrome;BSACI,British Society of Allergy and Clinical Immunology; CD,cluster of differentiation;DAIG,Drug Allergy Interest Group;DHR(s),drug hypersensitivity reaction(s);DPT(s),drug provocation test(s); EAACI,European Academy of Allergy and Clinical Immunology;EBV,Epstein–Barr virus;Fc e RI,high-afﬁnity IgE receptor;FDE,ﬁxed drug eruption;HHV,human herpes virus;HIV,human immunodeﬁciency virus;HLA,human leukocyte antigen;HSS/DRESS/DiHS,hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome;iCAALL,International Collaboration in Asthma,Allergy and Immunology;ICON,International CONsensus;IgE,immunoglobulin E;MCH,major histocompatibility complex;MDH, multiple drug hypersensitivity;NMBA,neuromuscular-blocking agents;NPV,negative predictive value;NSAID(s),nonsteroidal anti-inﬂammatory drug(s);RCM,radiocontrast media;SDRIFE,symmetrical drug-related intertriginous andﬂexural exanthema;SJS,Stevens–Johnson syndrome;TEN,toxic epidermal necrolysis;TNF-a,tumor necrosis factor alpha;WAO,World Allergy Organization.Demoly et al.ICON on drug allergypredictable due to the disease state(e.g.,human immunode-ﬁciency virus(HIV)infection/acquired immunodeﬁciency syndrome(AIDS),Epstein–Barr virus(EBV)infection)or a similar previous reaction to the same drug or drug class.Only when a deﬁnite immunological mechanism(either drug-speciﬁc antibody or T cell)is demonstrated,these reac-tions should be classiﬁed as drug allergy.For general communication,when an allergic drug reaction is suspected,Table1Recommendations for DHR diagnosis and managementNo.Statement Levels ofevidenceGrade ofrecommendation ReferencesR1Lifelong avoidance of the drug and cross-reactive drugsis recommended when drug-induced anaphylaxis has occurred4D(6,102) R2The speciﬁc allergy work-up should be carried out4–6weeksafter complete resolution of all clinical symptoms and signs of asuspected DHR4D(12,13)R3Sensitivity and predictive values of skin tests vary among drug classes:from‘good’for immediate DHRs to b-lactam antibiotics,musclerelaxants,platin salts and heparins,to moderate to low for mostother drugs2++B(22)R4Skin testing is helpful for diagnosis of immediate DHRsto iodinated RCM2+C(16,22)R5A DPT is the gold standard for the identiﬁcation of the drugeliciting a DHR2+C(6,8,13)R6For DPT,the oral route is preferred whenever possible3D(6,8,13) R7Contraindications must be observed before performing DPT,and immediate treatment available allowing complete andrapid recovery4D(6,8,13)R8Patients who suffered severe immediate reactions to b-lactamsand who displayed negative results at theﬁrst evaluation,which included a DPT,can be considered for retesting2–4weeksafter initial evaluation2ÀD(6,18)R9For currently available biological methods to diagnose drug allergy,a negative test does not exclude the imputability of thedrug,whilst a positive result shows sensitivity to the drugbut does not reliably conﬁrm causality 2+forß-lactams2Àto3forothersC(6,8)R10HLA-B*5701screening reduces the risk of DHR to abacavir and is mandatory before starting treatment 1++A(47)Not rated inpreviousconsensuses(6–23)R11An indicative,regularly updated list of drugs to avoid and thelist of possible alternatives should be given to patientswith a DHR4D(8)R12The search for safe alternatives may require DPTs in a hospitalsetting when the alternatives belong to the same drug class2+C(6,8,13)R13Speciﬁc questioning for a history of drug allergy by every clinicianprior to issuing a prescription is essential from both a medicaland a medico-legal view-point4D(6,8,20)R14Preventive measures by pre-medication(e.g.slow injection andpre-treatment with glucocorticosteroids and H1-antihistamines)are useful mainly for non-allergic DHRs,but corticosteroids andH1-antihistamines may not reliably prevent IgE-dependentanaphylaxis2+C(6,8,102)R15In the absence of generally accepted protocols for drug desensitizationin cases of immediate DHRs,reference to successfully appliedexisting protocols is recommended2+C(6,19)R16Desensitization to aspirin as a therapeutic intervention may beconsidered in selected asthmatic patients with aspirin exacerbatedrespiratory disease or nasal polyps2ÀD(6,19)DHR(s),drug hypersensitivity reaction(s);RCM,radiocontrast media;DPT(s),drug provocation test(s);HLA,human leukocyte antigen.ICON on drug allergy Demoly et al.DHR is the preferred term,because true drug allergy and nonallergic DHR (29)may be difﬁcult to differentiate based on the clinical presentation alone,especially in cases of acute severe DHR.ClassiﬁcationsThe classiﬁcation of DHRs is challenging because,for many drugs and clinical presentations,the underlying mechanism is poorly understood (Box 2).A generally accepted classiﬁca-tion should facilitate the comparison of studies and help to enhance and validate diagnostic techniques.Clinically,DHRs are commonly classiﬁed as immediate or nonimmediate/delayed depending on their onset during treatment (18).Immediate DHRs are possibly induced by an IgE-mediated mechanism and occur within 1–6h after the last drug administration (32)(Fig.1).Typically,they occur within the ﬁrst hour following the ﬁrst administration of a new course of treatment.They usually manifest as isolated symptoms such as urticaria,angioedema,conjunctivitis,rhinitis,bronchospasm,gastrointestinal symptoms (nausea,vomiting,diarrhea,abdominal pain),or as anaphylaxis oranaphylactic shock.In certain guidelines,when DHR symp-toms are systemic,non-IgE-dependent,and mimicking ana-phylaxis,they are designated as ‘anaphylactoid’reactions (6).This is no longer the case in EAACI and WAO (29)guidelines,where the term ‘nonallergic DHRs’is preferred.Nonimmediate DHRs may occur any time as from 1h after the initial drug administration.They commonly occur after many days of treatment and are often associated with a delayed T-cell-dependent type of allergic mechanism.Macu-lopapular exanthemas and delayed urticaria are the most common clinical presentations of nonimmediate DHRs.Although artiﬁcial,this classiﬁcation is very important in clinical practice for workup planning.In any case,a precise description of the morphology and chronology of the reac-tion is mandatory.But there are still limitations,because other factors such as the route of administration,the role of drug metabolites,and the presence of co-factors or co-prescribed drugs may accelerate or slow down the onset or progression of a reaction (32)(Fig.1).Mechanistically,drugs are capable of inducing all of the types of immunological reactions described by Gell and Coo-mbs (33),but the most common are IgE-and T-cell-mediated reactions (Table 2).Certain drugs,such as antiepileptic drugs and allopurinol,cause mainly T-cell-mediated reactions,while others,such as neuromuscular-blocking agents (NMBA),provoke mainly IgE-mediated reactions.Some of the others (e.g .,b -lactams)may lead to both types of reaction.Pathogenesis and pathophysiologyImmune/allergic and nonimmune/nonallergic DHRsDrug allergies are adverse reactions whereby antibodies and/or activated T cells are directed against the drugs oragainstDemoly et al.ICON on drug allergyone of its metabolites.Numerous reactions with symptoms suggestive of allergy are often erroneously considered to be real drug allergies.The suggested pathomechanisms of these reactions include the following:(i)nonspeciﬁc mast cell or basophil histamine release(e.g.,opiates,radiocontrast media, and vancomycin),(ii)bradykinin accumulation(angiotensin-converting enzyme inhibitors),(iii)complement activation (e.g.,protamine),(iv)possibly an alteration in arachidonate metabolism(e.g.,aspirin and nonsteroidal anti-inﬂammatory drugs),and(v)the pharmacological action of certain sub-stances inducing bronchospasm(e.g.,b-blockers,sulfur diox-ide[S02]released by pharmaceutical formulations containing sulﬁtes).Immediate allergic DHRsImmediate allergic DHRs develop as a result of IgE produc-tion by antigen-speciﬁc B lymphocytes after sensitization. IgE antibodies bind to the high-afﬁnity Fc RI receptors on the surface of mast cells and basophils,creating a multiva-lent binding site for the drug antigen(34).Following subsequent drug exposure,the antigen–presumably a hapten–protein complex–cross-links bound IgE,stimulating the release of preformed mediators(e.g.,histamine,tryptase, some cytokines such as TNF-a)and the production of new mediators(e.g.,leukotrienes,prostaglandins,kinins,other cytokines).The preformed mediators stimulate a response within minutes,whereas the cytokine inﬂammatory compo-nent develops after several hours,the time required for pro-tein synthesis and the recruitment of immune cells.b-Lactam-mediated anaphylaxis is the best deﬁned immediate allergic DHR(18).Nonimmediate/delayed allergic DHRsMost nonimmediate/delayed allergic DHRs are mediated through the actions of T lymphocytes(34).The skin is the most commonly targeted organ by drug-responsive T cells, but any organ can be involved.Diclofenac,for example,as well as several other carboxylic acid nonsteroidal anti-inﬂam-matory drugs,can cause immune-mediated liver injury,which may be explained by hepatic metabolism and selective modiﬁ-cation of hepatic proteins(35).It is important to note that the same drug might produce different clinical symptoms and signs in different individuals,despite the drug being adminis-tered at the same dose via the same route.We are lacking data regarding speciﬁc drug processing,but,based on peptide immune recognition,the following scenario is possible.To stimulate naive T cells,dendritic cellsﬁrst process the drug antigen.The antigen is then internalized and transported to the regional lymph nodes.To develop an effective immune response,the innate immune system needs to be activated, providing important maturation signals,often referred to as ‘danger signals’(36)which include direct drug or disease-related stress.On arrival at the lymph nodes,the antigen is presented to naive T cells.Alternatively,some drug antigens might directly stimulate pathogen-speciﬁc T cells,thus avoid-ing the requirement for dendritic cell priming of T cells.How-ever,for some authors,this hypothesis is difﬁcult to reconcile with the time between initial drug exposure and the develop-ment of clinical signs(34).Antigen-speciﬁc T cells migrate to target organs and,once re-exposed to the antigen,they are activated to secrete cytokines that regulate the response and cytotoxins(e.g.,perforin,granzymes,and granulysins)that produce tissue damage.Table2Classiﬁcation of drug allergies(adapted from(33))Type Type of immuneresponse Pathophysiology Clinical symptoms Typical chronology of the reactionI IgE Mast cell and basophildegranulation Anaphylactic shockAngioedemaUrticariaBronchospasmWithin1to6h after the last intake of the drugII IgG and complement IgG andcomplement-dependentcytotoxicityCytopenia5–15days after the start of the eliciting drugIII IgM or IgG andcomplement or FcR Deposition of immunecomplexesSerum sicknessUrticariaVasculitis7–8days for serum sickness/urticaria7–21days after the start of the eliciting drugfor vasculitisIVa Th1(IFN-c)Monocytic inﬂammation Eczema1–21days after the start of the eliciting drugIVb Th2(IL-4and IL-5)Eosinophilic inﬂammation Maculopapularexanthema,DRESS 1to several days after the start of the eliciting drug for MPE2–6weeks after the start of the eliciting drug for DRESSIVc Cytotoxic T cells(perforin,granzyme B,FasL)Keratinocyte deathmediated by CD4orCD8Maculopapular exanthema,SJS/TEN,pustularexanthema1–2days after the start of the eliciting drug forﬁxed drug eruption4–28days after the start of the eliciting drugfor SJS/TENIVd T cells(IL-8/CXCL8)Neutrophilic inﬂammation Acute generalizedexanthematouspustulosis Typically1–2days after the start of the eliciting drug(but could be longer)ICON on drug allergy Demoly et al.Chemical basis of drug allergiesAccording to the hapten hypothesis,in order to stimulate a reaction,a drug should act as a hapten and bind irreversibly to proteins(34),generating antigens.This theory is relevant for chemical compounds,but not for proteic or carbohydrate compounds of drugs such as insulin,enzymes,monoclonal antibodies,and recombinant proteins.This is also especially relevant for oral drugs that preferentially bind to proteins such as albumin in gastric stomachﬂuid(37).However,in most cases,the gastric peptic function digests and inactivates the hapten–protein complex.Several drug modiﬁcations of the same protein are possible,generating a multivalent anti-gen for eliciting IgE-mediated immediate DHRs.For the elic-itation of delayed-type T-cell-mediated reactions,the role of the carrier protein and/or the hapten has not always been fully deﬁned.Furthermore,it is not known as to whether there is a threshold level of modiﬁcation that needs to be sur-mounted to stimulate a T-cell response.The majority of drugs,however,are not directly protein reactive(33),and in such cases,hapten formation is thought to occur as a conse-quence of metabolic activation(e.g.,sulfonamides)(the pro-hapten hypothesis).By generating a reactive metabolite,it is also feasible that activation of the innate immune system occurs,which is a prerequisite for a classical immune response.An alternative hypothesis(the pharmacological interaction with immune receptor(p-i)concept)has evolved from analy-sis of the response of T-cell clones to drug stimulation,sug-gesting that drugs,although smaller than traditional antigens,might also interact directly with immunological receptors through a reversible interaction with the immune receptors(33).According to this hypothesis,a drug can directly bind and activate T cells(providing MHC binding as well)or bind to HLA molecules,which then activate T cells indirectly,by altering the MHC–peptide groove.This latter concept was recently further extended by showing that some drugs,when they bind to HLA molecules,promote an exchange of embedded peptides(38).However,the functional consequence of this peptide exchange is still unclear.Abaca-vir binds at the F pocket antigen-binding site of HLA-B*5701,selecting an array of novel self-peptides that induce the activation of CD8-positive T cells,inducing a severe DHR similar to graft-vs-host disease without eosinophilia (38).This recently uncovered mechanism of DHRs may be applicable to other small molecules with HLA allotype preferences.Pharmaco-and immunogenetic basis of drug allergiesDrug hypersensitivity reactions involve both immune-and nonimmune-mediated mechanisms,with strong genetic interplay in some severe nonimmediate/delayed allergic DHRs.Indeed,a strong association between carbamaze-pine-induced Stevens–Johnson syndrome/toxic epidermal necrolysis(SJS/TEN)has been described for HLA-B*1502 in a Han Chinese population(39)and subsequently in Indian(40)and Thai(41),but not in European and Japa-nese patients(42–45).The association seems to be pheno-type speciﬁc(SJS,but not hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome(HSS/DRESS/DiHS)) (46).In contrast,HLA-A*3101has been shown to be asso-ciated,in northern Europeans,with a spectrum of carba-mazepine-induced reactions including maculopapular exanthemas,DRESS/DIHS,and SJS/TEN(42).For the drug abacavir,an association between HLA-B*5701expres-sion and severe DHRs in Caucasians has been shown(47). The incidence of this allele in abacavir-hypersensitive patients is high(94.4%)(48)in the Australian cohort,but lower(22.2%)in other studies(49),although still signiﬁ-cantly higher than in the average population prevalence. Other genetic variants have been associated with DHRs (50)(Table3).In immediate DHRs,some cytokine gene polymorphisms have been weakly associated with b-lactam-induced anaphylaxis(51,52).Role of viruses in the pathogenesis of DHRsViral infections can lead to skin eruptions and mimic DHRs if a drug(mostly an antibiotic)is taken at the same time (53).Although they are the leading cause of skin eruptions, viral infections can also interact with drugs,leading to mild eruptions in the case of the‘ampicillin rash’linked to the EBV infection(54)and severe reaction during DRESS(55). Theﬁrst virus shown to be re-activated in DRESS patients was the human herpesvirus(HHV)-6(56),but all herpesvi-ruses can be involved(55).Strikingly,it was shown that HHV-6replication can be induced in vitro by amoxicillin (57).Clinical presentationsAcute and delayed manifestations of DHRsImmediate DHRs usually present in the form of isolated urti-caria,angioedema,rhinitis,conjunctivitis,bronchospasm, gastrointestinal symptoms(nausea,vomiting,diarrhea),or anaphylaxis,which can lead to cardiovascular collapse(ana-phylactic shock)(58).Nonimmediate DHRs often affect the skin with variable cutaneous symptoms(59–61)such as late-occurring or delayed urticaria,maculopapular eruptions,ﬁxed drug eruptions(FDE),vasculitis,blistering diseases (such as TEN,SJS,and generalized bullousﬁxed drug erup-tions),HSS,acute generalized exanthematous pustulosis (AGEP),and symmetrical drug-related intertriginous and ﬂexural exanthemas(SDRIFE).Internal organs can be affected either alone or with cutaneous symptoms(HSS/ DRESS/DiHS,vasculitis,SJS/TEN)and include hepatitis, renal failure,pneumonitis,anemia,neutropenia,and throm-bocytopenia.Danger/severity signs of DHRsThe approach to the patient with a presumed DHR in the acute phase involves the following steps:(i)a complete his-tory of the drugs taken(types,doses,duration),(ii)a detailed description of the symptoms and signs(types, onset,localization,and evolution),with(iii)a complete examination of the skin and the mucous membranes (including the mouth,eyes,and genitals),and(iv)theDemoly et al.ICON on drug allergy。

化工英语

一、专业单词absorptiometric analysis 吸光分析acetic acid 醋酸acetic acid glacial 冰醋酸acetic aldehyde 乙醛acetic anhydride 醋酐acetone 丙酮acetylene 乙炔acetylsalicylic acid 乙酰水杨酸acid of lemon 柠檬酸acridine 吖啶adamantane 金刚烷addition polymer 加聚物addition reaction 加成反应barite 重晶石barium 钡benzene hexachloride 六六六bromoform 溴仿burnt lime 生石灰butyraldehyde 丁醛calcium chloride 氯化钙calcium chloride tube 氯化钙管calcium chromate 铬酸钙calcium cyanamide 氰氨化钙calcium cyanide 氰化钙calcium fluoride 氟化钙calcium hydride 氢化钙calcium hydrosulfide 氢硫化钙dimerization 二聚酌dimethyl ether 二甲醚dimethyl phthalate 酞酸二甲酯dimethyl sebacate 癸二酸二甲酯dimethyl sulfate 硫酸二甲酯dimethyl sulfoxide 二甲亚砜dimethyl terephthalate 对酞酸二甲酯dimethylacetal 二甲基缩醛dimethylacetamide 二甲基乙酰胺dimethylamine 二甲胺dimethylaniline 二甲基苯胺dimethylarsine 二甲胂dimethylbenzene 二甲苯electron configuration 电子构型electron density 电子密度electron diffraction 电子衍射electron donor 电子供体electron emission 电子发射electron exchange 电子交换electron exchange resin 电子交换尸electron gas 电子气electron lattice interaction 电子点阵相互酌electron microscope 电子显微镜electron orbit 电子轨道free convection 自然对流free electron model 自由电子模型free energy 自由能free energy at constant pressure 定压自由能free energy of activation 活化自由能free expansion 自由膨胀free heat convection 自然对粱热free moisture 游离水分free path 自由程free radical 自由基free radical initiation 游离基开始反应free radical reaction 游离基反应gelometry 凝胶强度测定法gelose 琼脂gelsemine 钩吻碱甲gelseminic acid 钩吻酸gene 基因gene cloning 基因无性繁殖general chemistry 普通化学general formula 通式general theory of relativity 广义相对论generalized momentum 广义动量generating function 母函数generator gas 发生炉煤气geneva nomenclature 日内瓦命名法genom 基因组hydraulic modulus 水硬系数hydraulic press 水压机hydraulic radius 水力半径hydraulic separation 水力离析hydraulic test 水力试验hydraulicity 水凝性hydrazine 肼hydrazine sulfate 硫酸肼hydrazinium 肼hydrazo compound 肼基化合物hydrazobenzene 肼撑苯hydrazoic acid 叠氮酸hydrazone 腙isoamyl acetate 醋酸异戊酯isoamyl alcohol 异戊醇isoamyl benzoate 苯甲酸异戊酯isoamyl bromide 异戊基溴isoamyl butyrate 丁异戊酯isoamyl chloride 异戊基氯isoamyl ether 异戊醚isoamyl nitrite 亚硝酸异戊酯isoamyl propionate 丙酸异戊酸jet fuel 喷气发动机燃料jet pump 喷射泵jewel 宝石jig sieve 振动筛joule 焦耳joule effect 焦耳效应joule thomson effect 焦耳汤姆森效应joule's law 焦耳定律juglone 胡桃酮julian tube 凯撒管junker's calorimeter 容克量热计jute 黄麻karyoplasm 核质kata thermometer 卡他温度计kauri butanol value 贝壳杉脂丁醇值kauri gum 栲里松脂kauri resin 栲里松脂keene's cement 金纳水泥keesom relationship 基朔关系kelp 海草灰kelvin's temperature 开氏温度keratin 角蛋白keratin plastics 角质塑料kermes 胭脂虫粉kermesite 红锑矿kerogen 油母质lime sulfur mixture 石硫合剂lime water 石灰水limestone 石灰石liming 用石灰处理limit dextrin 有限糊精limit of error 误差极限limit of identification 证实限度limit of inflammability 可燃限度limiting concentration 极限浓度limiting current 极限电流limiting current density 极限电淋度limiting value 极限值limonene 二戊烯mannitol 甘露糖醇mannitol hexanitrate 六硝酸甘露醇mannonic acid 甘露糖酸mannose 甘露糖manocryometer 融解压力计manometer 压力计manostat 恒压器manufacture 制造manufacture of common salt 食盐制造法manufactured gas 人造煤气manufacturing cost 造价manufacturing in series 成批生产manufacturing method 制造法manufacturing process 制造法nodal plane 节平面nodal point 节点nomenclature 命名法nominal horsepower 标称马力nomogram 列线图解nomograph 列线图解nomography 列线图解法non adiabatic 非绝热的non adiabatic rectification 非绝热精馏non diffusible ion 固定离子non inflammable 耐火的non newtonian flow 非牛顿怜non return valve 逆止阀octyne 辛炔ocular 目镜ocular dichroscope 接眼二色镜ocular examination 目视检查法ocular micrometer 目镜测微计odd even nucleus 奇偶核odor 气味odorant 着嗅剂odorimeter 气味计odorimetry 气味测定法odoriphore 生臭团oenometer 酒度计permselectivity 选择渗透性permutation 置换permutite 人造沸石perovskite 钙钛矿peroxidase 过氧物酶peroxide 过氧化peroxide effect 过氧化物效应peroxide index 过氧化值peroxide number 过氧化值peroxo acid 过氧基酸peroxy acid 过酸peroxydisulfuric acid 过硫酸perpetual motion 永久运动perphenazine 佩吩嗪quantity of heat 热量quantity of state 状态量quantity production 大量生产quantization 量子化quantometer 光量计quantum 量子quantum chemistry 量子化学quantum condition 量子条件quantum efficiency 量子效率quantum hypothesis 量子假说quantum jump 量子跃迁quantum leakage 量子漏泄quantum liquid 量子液体quantum mechanics 量子力学quantum number 量子数rubber insulation 橡胶绝缘rubber isomer 橡胶异构体rubber latex 胶乳rubber like elasticity 似橡胶弹性rubber lining 橡皮衬里rubber resin 橡胶尸rubber solvent 橡胶溶剂rubber sponge 海绵橡胶rubber stopper 橡皮塞rubber substitute 油膏rubber thread 橡胶线rubber tube 橡皮管rubbing 磨损safety engineering 安全工程safety explosive 安全炸药safety factor 安全率safety film 安全软片safety fuel 安全燃料safety glass 安全玻璃safety lamp 安全灯safety match 安全火柴safety technique 安全工程safety valve 安全阀safflower oil 红花油saffron 擦粉safranal 藏花醛safranine 藏红safrole 黄樟素theory of valence 原子价理论thermal absorption 热吸收thermal activation 热活化thermal analysis 热分析thermal black 热炭黑thermal conductivity 导热系数thermal cracking 热分解thermal decomposition 热分解thermal diffusion 热扩散thermal diffusivity 热扩散系数thermal dissociation 热力离解thermal efficiency 热效率thermal equilibrium 热平衡thermal equivalent 热当量unsaturated hydrocarbon 不饱烃unsaturated solution 不饱和溶液unsaturation 不饱和unshared electron pair 未共享电子对unstable compound 不稳定化合物unstable equilibrium 不稳定平衡unsteady state 非稳定态untreated oil 未处理油料unusual valency 异常原子价unvulcanized rubber 未硫化橡胶vacuum evaporation 真空蒸发vacuum evaporation coating 真空镀膜vacuum evaporator 真空蒸发器vacuum filter 真空过滤器vacuum filtration 真空过滤vacuum flask 真空瓶vacuum forming 真空成型vacuum gage 真空计vacuum plating 真空镀膜water meter 水量计water of crystallization 结晶水water of hydration 水合水water paint 水性漆water permeability 渗水性water pipe 水管water purification 水的净化water purifier 净水器water purifying plant 净水设备water repellent 防水剂water resistance 抗水性water seal 水封xanthopterin 黄蝶呤xanthotoxin 黄原毒xanthurenic acid 黄尿酸xanthydrol 口山吨氢醇xenocryst 捕获晶xenon 氙xenon lamp 氙灯xerogel 干凝胶xylan 木聚糖xylene 二甲苯xylenol 二甲苯酚xylenol blue 二甲酚蓝xylenol orange 二甲酚橙xylenol resin 二甲苯酚尸yttrium bromide 溴化钇yttrium carbonate 碳酸钇yttrium chloride 氯化钇yttrium fluoride 氟化钇yttrium hydroxide 氢氧化钇yttrium iodide 碘化钇yttrium nitrate 硝酸钇yttrium oxide 氧化钇yttrium phosphate 磷酸钇yttrium sulfate 硫酸钇yttrium sulfide 硫化钇zeotrope 非共沸混合物zero adjustment 零点蝶zero group 零族zero method 零位法zero order reaction 零级反应zero point energy 零点能zero position 零位zero potential 零电势zerogel 零凝胶zeta potential 界面动电势ziegler catalyst 齐格勒催化剂zinc 锌二、专业文献(1) Nano-materials in the production of chemicalNano-materials in the structure, photoelectric and chemical nature of the attractive features, from physicists, materials scientists and chemists great interest. The early 1980s the concept of a nano-materials, the world of great concern to such material. It is the unique physical and chemical properties, so that people may be aware of it to the development of physics, chemistry, materials, biology, medicine and other disciplines bring new opportunities for research. Nano-materials application prospects are bright. In recent years, in the field of chemical production has also been a certain amount of applications, and demonstrated its unique charm.1. In the application of catalystsIn many chemical catalyst in the field of play a decisive role, it can be controlled response time and improve the efficiency of reaction and reaction speed. Most of the traditional catalyst not only by low efficiency, and its preparation is to use their experience, not only caused the tremendous waste of raw materials production, to improve economic efficiency, but also caused pollution to the environment. Nanoparticles surface active sites, as the catalyst for it to provide the necessary conditions. Nanoparticles in a catalyst, can greatly improve the efficiency of reaction, the reaction speed control, and even the original can not be the reaction can be carried out. Nanoparticles catalyst for the reaction than the normal speed of the catalyst 10 to 15 times.Nanoparticles Application more as a catalyst for the semiconductor photocatalyst, especially in the areas of organic matter. Dispersed in the solution of each of a semiconductor particles, similar to a short-circuit as a micro-battery, with energy than the bandgap semiconductor-rays scattered in the semiconductor, semiconductor nanoparticles absorbed light from electronic - hole right. In the electric field, electronics and hole separation, were moved to the surface of particles different locations, and similar components in the solution by oxidation and reduction reactions.Photocatalytic reaction to the reaction of many types, such as alcohol and hydrocarbon oxidation, and oxidation-reduction of inorganic ions, organic catalytic hydrogenation and dehydrogenation of amino acid synthesis, nitrogen fixation reaction, water purification treatment, water-gas shift, and so on, some of which are difficult to heterogeneous catalysis realize. Heterogeneous Photocatalysis semiconductor catalystcan effectively degrade organic pollutants in water. Nano TiO2, for example, both high photocatalytic activity, but also Acid and Basic Resistance, light stable, non-toxic and inexpensive easy to get, was the catalyst light-load the best choice. The article has reported that the silica gel used for the substrate, the system had a higher catalytic activity TiO/SiO2-Supported Catalysts. Ni Cu or Zn compound of a nano-particles, some of organic compounds on the hydrogenation reaction is an excellent catalyst, can be a substitute for expensive platinum catalyst or button. Nano-platinum and ethylene oxide catalysts enable the reaction temperature from room temperature to 600 ℃. Nanoparticles used as catalyst improve the efficiency of reaction, the reaction path optimization, the reaction rate increased research in the fields of science and the future can not be ignored by an important research topic is likely to Catalysis in Industrial Application bring about revolutionary changes.2. In the application of paintNano-materials because of its special nature and structure of the surface with general access to the material excellent performance demonstrated strong vitality. Surface coating technology is the focus of attention of the world today. Nano-materials for the surface coating provided a good opportunity to make the function of the material has great potential. With traditional coating technology, add nanomaterials, nano-composite coating will be to achieve a leap in functionality means that the traditional function of coating modified. Coating their use can be divided into functional coatings and coating. That the structure is coated substrate coating raise some of nature and modification; functional coating to the substrate is not available in performance, access to traditional coating did not function. A superhard coatings, wear-resistant coatings, anti-oxidation, heat-resistant, fire-retardant coating, corrosion-resistant, decorative coatings, and other functional coatings are absorbing light, reflected light, light choice of the optical absorption coatings, conductive, insulation, electrical characteristics of semiconductor coating, oxygen-min, humidity, and gas-sensing properties of the coating, such as sensitive. In the paint by adding nano-materials can further enhance its defense capabilities and achieving anti-ultraviolet radiation, atmospheric against resistance and anti-degradation, discoloration, in the application of sanitary products can play a role in cleaning sterilization. Signs in the use of Nano-coating, can use its optical properties, to store solar energy, energy conservation purposes. In building materials such as glass, paint adding suitable nano-materials, and they can reduce the transmission of light and heat transfer effects, a thermal insulation, fire-retardant, and other effects.Japan's Matsushita has developed a good electrostatic shielding the nanocomposite coating, the application of iron oxide nanoparticles have, titanium dioxide and zinc oxide, etc.. Such a semiconductor properties of nano-oxide particles at room temperature than conventional oxides have high electrical conductivity properties, which can play a role in electrostatic shielding, and oxide nanoparticles of different colors, such can also compound control electrostatic shielding paint color, carbon black overcome electrostatic shielding paint only the monotony of a single color. Nano-materials not only with the size and color change also has the effect of discoloration angle. In the automobile industry in the decorative spraying will be added Nano TiO2 in the automotive, metal flashlight Topcoat sedan, the coating can produce rich and mysterious colors, so that an old traditional automotive topcoat Huanxinya. Nano-SiO2 is a resistance to ultraviolet radiation materials. In the paint by adding nano-SiO2 can paint anti-aging properties, finish and strength increased manifold. Nano coating have a good prospect, coating technology will bring a new technological revolution, it will promote the research and development of composite materials and applications.3. Other in the use of chemicalFine Chemicals is a huge industry, the number of many products, a wide range of uses, and affect every aspect of human life. Nanomaterials superiority will certainly bring the Gospel to the chemical, and display of its unique plot. In the rubber, plastics, paints and other chemical fields, nano-materials can play an important role. If included in the rubber nano-SiO2 can be enhanced rubber anti-UV radiation and infrared reflectivity. Nano-Al2O3 and SiO2, by adding to the general rubber, rubber can improve the wear resistance and dielectric properties, but also flexibility is better than for white carbon black rubber filler. Plastic add some nano-materials, can improve the strength and toughness of plastic, and compact and waterproof and has correspondingly increased. Nano-SiO2 has been abroad, as additives into sealants and adhesives, sealing and adhesion to have greatly improved. In addition, nano-materials in the fiber modification, plexiglass manufacturers also have good applications. After adding in the plexiglass surface modification with SiO2, plexiglass resistance to ultraviolet radiation can achieve the purpose of anti-aging; A12O3 to join, not only do not affect the transparency of the glass, but it will also enhance the high-temperature impact toughness of the glass. Certain size anatase TiO2 have excellent UV shielding performance, but also delicate texture, non-toxic odorless, add in cosmetics, cosmetics performance can be improved. Ultrafine TiO2 can be extended to the application of coatings, plastics, man-made fibres industries. Recently developed for food packaging TiO2 and luxury cars pearlescent finish withthe Titanium Dioxide. Nano TiO2 to strong sunlight absorption in the UV, generate strong photochemical activity can be consumed by the industrial degradation of organic pollutants in the wastewater, with the exception of high-net, no secondary pollution, the advantages of broad applicability, Environmental water treatment has good prospects. In the field of environmental science, in addition to use of nanomaterials as a catalyst to deal with emissions from industrial production processes in the waste, there will be unique nano-membrane function. This membrane can detect chemical and biological agents from the pollution caused, and is able to filter these agents, thereby eliminating pollution.4. In the application of Chinese medicine21st century health sciences, will be expected to speed access to the development, the people's growing demand for high drug. Control drug release, reduce side effects and improve efficacy, the development of targeted drug therapy, has been mentioned research agenda. Nanoparticles drugs in the human body will make the transmission more convenient. With several layers of nano-particles coated smart drugs enter the body, may take the initiative to search and attack cancer cells or repairing damage; use of a new type of nano-technology diagnostic apparatus, a small amount of blood can be detected only through which the protein and DNA diagnosis of various diseases, the Massachusetts Institute of Technology has produced a nano-magnetic material to the target as a drug carrier directional drugs, called "directional missile." This technology is in the magnetic nanoparticles coated surface protein carrying drugs, injected into the blood vessels of the human body through magnetic navigation transported to lesions, and then the release of drugs. Nanoparticles small size, can flow freely in the bloodstream, it can be used to examine and treat the physical location of lesions. Nanoparticles on the clinical and radiological treatment is the application of a great deal of research work. According to "People's Daily" reported that China will be used in nano-technology medical field success. Nanjing Xike groups use nano-silver technology to the development and production of medical dressings - long-term broad-spectrum antimicrobial cotton. Antibacterial cotton production this principle through nano-technology will be made of silver nano-size in the small ultra-fine particles, and then make it attached to the cotton fabric. Silver is the prevention of ulcers and accelerate wound healing role, through nano-technology deal with the silver surface increases rapidly, changes in the structure of the surface, disinfection raise about 200 times the common clinical surgical infection have better inhibition of bacteria .And satisfied that the tablets as particulate delivery systems, the basicnature of the material is non-toxic, stable, and there are good biological and drug and not a chemical reaction. Nano system is mainly used for toxicity, short biological half-life, susceptible to biological degradation of the drug administration.Nano-biology used to study the nano-scale biological processes, in accordance with principles of molecular biology applications engineering. Rail in the ultrafine particles of metal surface covered a thickness of 5 to 20 nm polymer, can be fixed in particular a large number of proteins and thus control biochemical reactions. This biochemical technology, enzyme engineering in the great usefulness. Nano-technology and the integration of biology, molecular biology research devices using nano-sensors, can be obtained within the cell biological information to understand the body state and deepen people's physiological and pathological explanation.5. ConclusionNano-science is a keeper of basic science and applied science in integrated set of emerging science, including nano-electronics, nano-materials science, biology and nanotechnology. The 21st century will be the era of nano-technology is, to that end, the State Science Commission, the Chinese Academy of Sciences will be nano-technology as "the 21st century's most important and most leading edge of science." Nano-materials applications relate to various areas in mechanical, electronic, optical, magnetic, chemical and biological fields have broad application prospects. The birth of nano-science and technology, human society will have a far-reaching impact, and is likely to fundamentally solve the many problems facing humanity, particularly energy, human health and environmental protection, and other major issues. Beginning of the 21st century is the main task of all kinds of novel nano-materials basis of the physical and chemical characteristics, design of new materials and devices. Through nano-materials science and technology on the traditional products modified to increase its high-tech content and the development of a new type of nano-structured products, there have been encouraging signs, with the formation of 21 new economic growth points basis. Nano materials will become a field of materials science show the grade star in the new materials, energy, information and other fields, play a pivotal role. With its preparation and modification technology and the continuing development of nano-materials in the chemical and pharmaceutical production, and other areas will be increasingly wider range of applications.纳米材料在化工生产中的应用纳米材料在结构、光电和化学性质等方面的诱人特征，引起物理学家、材料学家和化学家的浓厚兴趣。

可降解塑料及其微生物降解研究进展

Advances in Environmental Protection 环境保护前沿, 2023, 13(3), 670-678 Published Online June 2023 in Hans. https:///journal/aep https:///10.12677/aep.2023.133083可降解塑料及其微生物降解研究进展吴佳云*，李茹欣*，陈恩祈，卢得雨，谢桂英，杜星辰，钟宇晴，邓博晖，成彩霞，廖三阳子，黄金岚，黄玉杰#，曾斌#深圳技术大学药学院，广东深圳收稿日期：2023年5月19日；录用日期：2023年6月19日；发布日期：2023年6月28日摘要为了缓解塑料制品广泛使用造成的环境污染，人们逐渐使用可降解塑料代替传统塑料。

根据后期处理方式的差异，可降解塑料主要可分为四大类：光降解塑料、生物降解塑料、化学降解塑料、光/氧–生物复合降解塑料。

其中，生物降解塑料的应用最为广泛。

根据化学结构和性能上的不同，目前常用的可降解塑料主要可分为聚α-羟基酸类、二元酸二元醇共聚酯类、聚羟基烷酸酯类及淀粉基类。

本文我们综述了近年来国内外研究者针对以上四类生物降解塑料的降解条件及机理等相关研究进展，并整理了可降解生物塑料的主要微生物研究及种类等信息，有助于对可降解塑料的深入认识、新型可降解塑料的研制及优质降解方法的开发。

关键词塑料，可降解塑料，生物降解塑料，微生物降解Research Progress on Biodegradable Plastics and Their Microbial DegradationJiayun Wu *, Ruxin Li *, Enqi Chen, Deyu Lu, Guiying Xie, Xingchen Du, Yuqing Zhong, Bohui Deng, Caixia Cheng, Sanyangzi Liao, Jinlan Huang, Yujie Huang #, Bin Zeng #Pharmaceutical College of Shenzhen University of Technology, Shenzhen GuangdongReceived: May 19th , 2023; accepted: Jun. 19th , 2023; published: Jun. 28th , 2023AbstractIn order to alleviate the environmental pollution caused by the widespread use of plastic prod-*共同第一作者。

描写穿山甲的英语作文

As a high school student with a keen interest in wildlife, Ive always been fascinated by the enigmatic creature known as the pangolin. This essay is an attempt to share my knowledge and experiences about these unique animals, which are often referred to as the scaly anteaters.Pangolins are mammals that are native to Asia and Africa. They are the only known mammals to have evolved scales made of keratin, the same material found in human hair and nails. These scales serve as a defense mechanism, allowing them to curl into a ball when threatened, protecting their soft underbellies from predators.My fascination with pangolins began when I was introduced to them in a wildlife documentary. The documentary highlighted the plight of these animals, which are often targeted for their scales and meat, leading to a significant decline in their population. This sparked my curiosity, and I began to research more about these elusive creatures.One of the most intriguing aspects of pangolins is their feeding habits. As nocturnal animals, they spend most of their time foraging for ants and termites, using their long, sticky tongues to extract these insects from their nests. Their strong, curved claws are also adapted for digging into the ground or tree bark to access insect colonies.During a school trip to a wildlife sanctuary, I had the opportunity to observe a pangolin up close. The sanctuary had rescued a pangolin that had been injured by a poachers trap. Seeing this gentle creature in person was a humbling experience. Its scales were rough to the touch, but its eyesheld a softness that conveyed a sense of vulnerability.Pangolins are also known for their solitary nature. They are not social animals and prefer to live alone, only coming together during mating season. This solitary lifestyle makes them even more challenging to study, as they are rarely seen in the wild.However, the pangolins existence is under severe threat due to poaching and habitat loss. Their scales are believed to have medicinal properties in some cultures, and their meat is considered a delicacy in certain regions. This has led to an increase in illegal hunting, pushing some species of pangolins to the brink of extinction.In recent years, there has been a growing awareness about the plight of pangolins, with many conservation efforts being initiated to protect them. These efforts include antipoaching patrols, habitat preservation, and public education campaigns to raise awareness about the importance of pangolins in the ecosystem.As a student, I feel it is crucial to contribute to these conservation efforts. I have participated in awareness campaigns at my school, sharing information about pangolins and the threats they face. I have also volunteered at local wildlife sanctuaries, helping to care for rescued pangolins and other endangered species.In conclusion, pangolins are extraordinary creatures that deserve our attention and protection. Their unique adaptations, solitary lifestyle, andthe challenges they face due to human activities make them a compelling subject for study and conservation. As a society, we must take action to ensure the survival of these remarkable animals, not just for their sake, but for the health of our planets ecosystems as a whole.。

穿山甲英文作文初一

穿山甲英文作文初一English: Pangolin is a unique and intriguing animal that is also known as the "scaly anteater". Pangolins are covered in tough, overlapping scales made of keratin, the same material found in human nails and hair. They are found in tropical regions of Africa and Asia, and are known for their distinctive walking style, using their hind legs and their tails for support. Pangolins are insectivorous, feeding on ants and termites using their long, sticky tongues. Unfortunately, pangolins are highly endangered due to illegal poaching for their scales, which are believed to have medicinal properties in some cultures. Conservation efforts are being made to protect and raise awareness about the plight of these unique creatures.中文翻译: 穿山甲是一种独特而引人入胜的动物，也被称为“鳞翅目”。

穿山甲的身上覆盖着坚硬、重叠的鳞片，由角蛋白构成，这与人类指甲和头发中所含的物质相同。

关于保护穿山甲的英语作文

关于保护穿山甲的英语作文英文回答：As an animal lover, I am deeply concerned about the protection of pangolins. Pangolins are unique creaturesthat are often referred to as "scaly anteaters" due totheir tough, overlapping scales. These scales are made of keratin, the same material found in human hair and nails.Unfortunately, pangolins are facing a serious threat from poaching and illegal trafficking. Their scales are highly sought after in traditional Chinese medicine, despite there being no scientific evidence to support their medicinal properties. As a result, pangolins are being hunted at an alarming rate, pushing them closer to the brink of extinction.In addition to poaching, habitat loss is also a major threat to pangolins. Deforestation and urbanization are destroying their natural habitats, leaving them withlimited space to roam and find food. Without proper protection and conservation efforts, pangolins may soon disappear from the wild.One way to help protect pangolins is by raising awareness about the issues they face. By educating the public about the importance of pangolins in the ecosystem and the threats they are facing, we can encourage people to take action to protect these unique animals. This could involve supporting organizations that work to conserve pangolin populations, or simply spreading the word onsocial media.Another way to help pangolins is by supporting sustainable tourism initiatives that promote responsible travel and wildlife conservation. By choosing to visit wildlife reserves and sanctuaries that prioritize animal welfare and conservation, we can help ensure that pangolins and other endangered species are protected for future generations to enjoy.In conclusion, pangolins are fascinating creatures thatdeserve our protection and respect. By taking action to raise awareness, support conservation efforts, and make responsible choices as consumers and travelers, we can all play a part in ensuring the survival of pangolins in the wild.中文回答：作为一个热爱动物的人，我对保护穿山甲问题深感关注。

皮肤渗透率英语

皮肤渗透率英语Skin PermeabilityThe human skin is a complex and multifunctional organ that serves as a barrier between the internal environment of the body and the external environment. One of the key properties of the skin is its permeability, which refers to the ability of substances to penetrate through the skin and reach the underlying tissues or the systemic circulation. Understanding skin permeability is crucial in various fields, including dermatology, pharmacology, and cosmetics, as it has significant implications for the delivery of topical treatments, the absorption of chemicals, and the overall health and well-being of the individual.The skin's permeability is primarily determined by the structure and composition of the stratum corneum, which is the outermost layer of the epidermis. The stratum corneum is composed of flattened, keratinized cells called corneocytes, which are embedded in a lipid-rich matrix. This unique structure, known as the "brick and mortar" model, provides the skin with its barrier function, limiting the penetration of various substances.The permeability of the skin is influenced by several factors, including the physicochemical properties of the substance, the skin's condition, and environmental factors. The physicochemical properties of a substance, such as its molecular weight, lipophilicity, and ionization state, can significantly impact its ability to penetrate the skin. Generally, smaller, lipophilic molecules with a neutral charge are more likely to penetrate the skin effectively.The skin's condition can also affect its permeability. Factors such as age, hydration, and the presence of skin conditions or injuries can alter the barrier function of the stratum corneum, either increasing or decreasing the skin's permeability. For example, as we age, the skin's barrier function may become less effective, leading to increased permeability and a higher risk of skin irritation or absorption of harmful substances.Environmental factors, such as temperature, humidity, and exposure to ultraviolet radiation, can also influence skin permeability. Increased temperature and humidity can enhance the skin's permeability by affecting the fluidity and organization of the lipid matrix in the stratum corneum. Conversely, exposure to ultraviolet radiation can disrupt the skin's barrier function, leading to increased permeability and a higher risk of skin damage.The assessment of skin permeability is crucial in various applications,particularly in the development of topical and transdermal drug delivery systems. Researchers and pharmaceutical companies use a variety of in vitro and in vivo methods to evaluate the permeability of the skin, including the use of artificial membranes, excised skin samples, and human or animal skin models. These techniques allow for the measurement of the rate and extent of penetration of various substances through the skin, which can inform the design and optimization of drug delivery systems.In the field of cosmetics, skin permeability is also an important consideration, as it determines the effectiveness of topical products and the potential for the absorption of harmful chemicals. Cosmetic manufacturers often conduct extensive testing to ensure the safety and efficacy of their products, taking into account the permeability of the skin and the potential for adverse reactions.In addition to its relevance in drug delivery and cosmetics, skin permeability is also an important consideration in the assessment of the potential toxicity of chemicals and environmental pollutants. Understanding the ability of these substances to penetrate the skin can help in the development of risk assessment strategies and the implementation of appropriate safety measures to protect human health and the environment.In conclusion, the permeability of the skin is a complex andmultifaceted property that plays a crucial role in various fields, from dermatology and pharmacology to cosmetics and toxicology. By understanding the factors that influence skin permeability and the methods used to assess it, researchers and practitioners can develop more effective and safer products, improve the delivery of topical treatments, and better protect human health and the environment.。

写穿山甲的优秀作文

写穿山甲的优秀作文Pangolins are fascinating creatures that inhabit the forests of Asia and Africa. 穿山甲是一种神奇的动物，生活在亚洲和非洲的森林里。

They are often referred to as "scaly anteaters" due to their unique appearance and diet. 由于穿山甲独特的外表和饮食习性，它们经常被称为“鳞甲食蚁兽”。

These gentle animals are covered in scales made of keratin, which serve as their protection from predators. 这些温和的动物身披角质鳞片，可以保护它们免受捕食者的伤害。

Despite their tough exterior, pangolins are sadly one of the most trafficked animals in the world. 尽管外表坚硬，但穿山甲却是世界上遭受走私最严重的动物之一。

Pangolins play a crucial role in their ecosystem as natural pest controllers. 穿山甲在生态系统中扮演着至关重要的角色，是天然的害虫控制者。

They help regulate insect populations by feeding on ants and termites, which in turn benefits the health of the forests they inhabit. 穿山甲通过捕食蚂蚁和白蚁来调节昆虫种群，从而有益于它们所生存的森林的健康。

Without pangolins, these insect populations could potentially grow out of control and cause damage to the ecosystem. 如果没有穿山甲，这些昆虫种群可能会失控，并对生态系统造成破坏。

求一片关于保护穿山甲的英语作文

求一片关于保护穿山甲的英语作文Protecting PangolinsPangolins are unique mammals that are often referred to as scaly anteaters. There are eight species of pangolins in the world, four in Asia and four in Africa. These animals are covered in tough, overlapping scales made of keratin, the same material that makes up our hair and nails. Pangolins are mainly nocturnal and feed on ants and termites by using their long tongues.Unfortunately, pangolins are facing a serious threat due to illegal wildlife trade. They are the most trafficked mammals in the world, primarily because their scales are believed to have medicinal properties in some cultures. Pangolins are also a delicacy in some parts of Asia, leading to their capture and sale in illegal wildlife markets. As a result, all eight species of pangolins are now listed as either vulnerable, endangered, or critically endangered on the International Union for Conservation of Nature (IUCN) Red List.To combat the illegal trade of pangolins and protect these unique creatures, conservation efforts must be made on multiple fronts. First and foremost, there must be stricter enforcement of laws against poaching and trafficking of pangolins. This includesincreasing penalties for those caught involved in the illegal trade and cracking down on wildlife trafficking networks. Governments must also work together to strengthen international cooperation in dealing with the illegal wildlife trade.Education and awareness are also crucial in protecting pangolins. Many people are not aware of the plight of these animals or the consequences of their illegal trade. By promoting awareness campaigns and educating the public about the importance of pangolins in their ecosystems, we can reduce the demand for pangolin products and discourage the illegal trade.Conservation efforts must also focus on protecting pangolin habitats. Deforestation and habitat destruction are major threats to pangolins, as they rely on forests and grasslands for food and shelter. Establishing protected areas and wildlife reserves where pangolins can thrive is essential in ensuring their long-term survival.In addition, research and monitoring are key components of pangolin conservation. Understanding the behavior, ecology, and population dynamics of pangolins is essential in developing effective conservation strategies. Scientists and conservationists must work together to study pangolins in their natural habitats and gather data to inform conservation efforts.As individuals, we can also contribute to the protection of pangolins. By avoiding the purchase of pangolin products and supporting conservation organizations that work to protect these animals, we can help reduce the demand for illegal pangolin trade. We can also spread the word about the importance of pangolins and the threats they face, raising awareness in our communities and advocating for their protection.Pangolins are unique animals with a vital role to play in their ecosystems. It is our responsibility to take action to protect these creatures and ensure that they are not driven to extinction by the illegal wildlife trade. By working together to enforce laws, raise awareness, protect habitats, conduct research, and support conservation efforts, we can help secure a future for pangolins in the wild. Let us all stand together to protect pangolins for future generations to admire and appreciate.。

0.05％丁酸氯倍他松乳膏的临床应用

0.05％丁酸氯倍他松乳膏的临床应用宣晓梅;董伟兰;柴越【摘要】目的局部外用皮质类固醇具有抗炎、抗增殖、抑制免疫及抗毒素等作用,在炎症性皮肤病中应用较为广泛.0.05％丁酸氯倍他松乳膏作为中效外用皮质类固醇临床应用已有40余年,循证医学研究显示治疗湿疹、银屑病等疗效肯定,安全性良好.【期刊名称】《皮肤病与性病》【年(卷),期】2019(041)002【总页数】4页(P189-192)【关键词】丁酸氯倍他松;皮炎;湿疹;银屑病;单一应用;联合应用;不良反应【作者】宣晓梅;董伟兰;柴越【作者单位】河北医科大学第一医院皮肤科,河北石家庄050031;河北医科大学第一医院皮肤科,河北石家庄050031;河北医科大学第一医院皮肤科,河北石家庄050031【正文语种】中文【中图分类】R751.05;R977.10.05%丁酸氯倍他松作为中效皮质类固醇，单用或与其他药物联合应用在皮炎湿疹及其它炎症性皮肤领域均获得了良好的治疗效果[1]。

2001年英国将其列为P类药物（非处方药）[2]，日本将其软膏用于婴幼儿[3]，疗效和安全性均得到认可。

本文就0.05%丁酸氯倍他松的临床应用、适应证、不良反应等作如下综述，为临床应用提供依据。

1 丁酸氯倍他松药理学特征在国内外的四和五级效能分级中，0.05%丁酸氯倍他松乳膏依据血管收缩效能定为中效[4、5]。

广泛应用于急性湿疹、过敏性皮炎及其他炎症性皮肤病的短期治疗，该结果基于3 500名受试者参与的29项临床试验报告以及超过25年的临床经验[6]。

研究表明，0.05%丁酸氯倍他松具有良好的抗炎和免疫抑制活性，其抗炎活性可有效减少皮炎、湿疹所伴随的红斑和瘙痒等症状，且局部活性高而全身活性吸收甚微[3]，对下丘脑-垂体-肾上腺（HPA）轴功能几乎没有影响，甚至全身大面积用于成人患者时也未对HPA轴功能产生影响[6]。

2 丁酸氯倍他松在炎症性皮肤病中的应用2.1 单一应用2.1.1 丁酸氯倍他松在皮炎湿疹中的应用一项22例特应性皮炎（AD）儿童患者比较0.05%丙酸氟替卡松乳膏（FP）与0.05%丁酸氯倍他松乳膏（CB）治疗的研究。

我最喜欢的动物英语作文,濒临灭绝的

我最喜欢的动物英语作文,濒临灭绝的全文共3篇示例，供读者参考篇1My Favorite Endangered AnimalI have always been fascinated by animals, but there is one in particular that holds a special place in my heart – the Amur leopard. This majestic cat, native to the Russian Far East and northeastern China, is one of the most endangered big cats in the world. With only around 100 individuals left in the wild, the Amur leopard is on the brink of extinction.The Amur leopard is a sight to behold, with its beautiful coat of spotted fur and its powerful build. They are incredibly elusive and shy, making sightings in the wild a rare and special experience. Unfortunately, habitat loss, hunting, and poaching have driven this magnificent animal to the edge of extinction.I first learned about the plight of the Amur leopard when I was in school, and ever since then, I have been passionate about raising awareness and supporting conservation efforts for this endangered species. Through my research and activism, I havecome to understand the importance of protecting not just the Amur leopard, but all endangered animals.Conservation efforts for the Amur leopard are ongoing, with organizations working tirelessly to protect their habitat, prevent poaching, and raise awareness about the importance of preserving this critically endangered species. It is crucial that we take action now to prevent the extinction of these majestic animals.In conclusion, the Amur leopard is my favorite animal not just because of its beauty and grace, but because of the urgent need to protect it from extinction. I will continue to support conservation efforts for the Amur leopard and other endangered animals, and I hope that future generations will be able to witness these incredible creatures in the wild.篇2My Favorite Endangered AnimalI have always been fascinated by animals, but one particular species holds a special place in my heart - the pangolin. These unique creatures are often overlooked, but they play a vital role in our ecosystem. Unfortunately, they are also one of the most endangered animals in the world.Pangolins are covered in scales made of keratin, the same material found in human hair and nails. They use these scales as a form of protection, rolling up into a ball when threatened. Pangolins are primarily insectivores, using their long tongues to slurp up ants and termites. Despite their armor-like exterior, pangolins are incredibly gentle creatures.There are eight species of pangolins, four of which are found in Africa and four in Asia. All eight species are facing threats to their survival, mainly due to habitat loss and illegal wildlife trade. Pangolins are often hunted for their scales, which are believed to have medicinal properties in some Asian cultures. As a result, their populations have declined dramatically in recent years.I have always been drawn to pangolins because of their unique appearance and behavior. I find it heartbreaking to think that these incredible animals are at risk of extinction due to human activities. It is important for all of us to do our part to protect pangolins and other endangered species by supporting conservation efforts and raising awareness about their plight.In conclusion, the pangolin is my favorite endangered animal because of its fascinating characteristics and the urgent need to protect it from extinction. I hope that by spreadingawareness and taking action, we can ensure that pangolins continue to thrive in the wild for generations to come.篇3My Favorite Endangered AnimalPandas are my favorite animals. The panda is a symbol of peace and friendship. Their cute appearance and gentle nature have captured the hearts of people all over the world. Unfortunately, pandas are also an endangered species.Pandas used to roam in the wild throughout much of China. However, due to habitat loss, poaching, and other human activities, their population has declined rapidly in recent decades. Today, there are less than 2,000 pandas left in the wild.One of the main reasons for the decline of pandas is habitat loss. As China's population grows and more land is needed for agriculture and development, the pandas' bamboo forests are disappearing at an alarming rate. Without their natural habitat, pandas cannot survive.Another major threat to pandas is poaching. Poachers hunt pandas for their fur and other body parts, which are believed to have medicinal properties. Despite strict laws and conservation efforts, poaching continues to be a serious problem for pandas.In order to save pandas from extinction, we need to take action now. Conservation efforts such as establishing nature reserves, protecting their habitats, and cracking down on poaching are all necessary steps to ensure the survival of pandas.As individuals, we can also do our part to help pandas. By supporting conservation organizations, spreading awareness about the plight of pandas, and making environmentally friendly choices in our daily lives, we can all contribute to the protection of these beloved animals.In conclusion, pandas are my favorite animals, and it breaks my heart to see them facing the threat of extinction. It is up to us to take action and ensure that pandas continue to thrive in the wild for generations to come. Let's work together to protect these gentle giants and preserve their natural habitat for all to enjoy.。

保护濒危穿山甲英语作文初二

保护濒危穿山甲英语作文初二The pangolin, a creature as ancient as the dinosaurs, is now on the brink of extinction. This small, armored mammal is facing a dire threat due to poaching and habitat loss.Their unique scales, made of keratin, are wronglybelieved to have medicinal properties, driving a black market trade that is decimating their populations. It's not justtheir scales that are in danger; pangolins are also victimsof habitat destruction as forests are cleared for agriculture and development.Education is key to saving the pangolin. By spreading awareness about their plight, we can help to dispel myths and reduce demand for their scales. Young people have a crucial role to play in this, as they are the future custodians ofour planet.Conservation efforts are underway, with wildlife organizations working tirelessly to protect these shy animals. They are implementing strategies such as anti-poaching patrols, habitat restoration, and captive breeding programs.However, the fight to save the pangolin is not just the responsibility of conservationists. It requires a collective effort from governments, communities, and individuals alike. We must all take action to ensure that future generations can continue to marvel at these extraordinary creatures.One simple way to help is by supporting organizationsthat are on the front lines of pangolin protection. Donating, volunteering, or even just sharing information about their work can make a difference.In conclusion, the pangolin's survival is a test of our commitment to biodiversity. It's a reminder that every species, no matter how small, plays a vital role in the delicate balance of our ecosystems. Let's act now to ensure that the pangolin doesn't become just another entry in the annals of extinct species.。

什么是湿润烧伤膏

什么是湿润烧伤膏舒叶【期刊名称】《中国烧伤创疡杂志》【年(卷),期】2012(24)5【摘要】目的通过美宝湿润烧伤膏的基本组成部分及国内外基础研究结果对湿润烧伤膏的几大作用机理做详细解读。

方法对国内外近20年已发表的关于美宝湿润烧伤膏机理研究的论文做回顾性总结，对美宝湿润烧伤膏在烧伤创面的作用：建立和保持生理性湿润环境、止痛作用、无损伤液化排出创面坏死组织、抗炎作用、防瘢作用、抑菌作用、皮肤再生(角蛋白19型干细胞激活及烧伤创面皮肤生理性愈合)进行系统论证及数据分析。

结果美宝湿润烧伤膏在烧伤创面上能切实有效地发挥上述作用。

结论美宝湿润烧伤膏作为烧伤再生医学与疗法的配套药膏在创面治疗及全身系统治疗中发挥了重要作用，是当今烧伤治疗中的黄金疗法。

% Objective To illustrate the properties of Moist Exposed Burn Ointment through the analysis of its com-positions and the presentation of basic studies at home and abroad on Moist Exposed Burn Ointment. Methods A retro-spective summary was given on the published papers in domestic and oversea journals in the recent 20 years regarding mech-anisms of Moist Exposed Burn Ointment. The systemic demonstration and data support were provided to testify the following properties of Moist Exposed Burn Ointment: creation and maintenance of physiologically moist environment, analgesic effect, liquefaction and discharge of necrotic tissues without secondary damage to potential viable tissues, anti-inflammatory effect, anti-scarring effect, bacteriostatic effect, skin regeneration (activation of keratin-19 stem cell and physiological heal-ing of burn wound). Results Moist Exposed Burn Ointment exerts the above effects in a solid and effective way. Conclu-sion Moist Exposed Burn Ointment, as the topical agent attached with Burns Regenerative Medicine and Therapy has the significant effects in wound care and systemic care of burn patients. Moist Exposed Burn Ointment is the golden standard in the treatment of burn injuries.【总页数】1页(P359-359)【作者】舒叶【作者单位】100020 北京，中国中西医结合学会烧伤专业委员会外事办【正文语种】中文【相关文献】1.湿润烧伤膏联合美宝创疡贴与单纯使用湿润烧伤膏治疗Ⅲ期压疮疗效对比分析[J], 秦泽红;孙玉勤;贺满菊2.湿润烧伤膏治疗烧伤残余创面的临床疗效及安全性 [J], 简繁;赵守和;马森3.负压封闭引流联合湿润烧伤膏治疗糖尿病足疗效分析 [J], 张伟4.湿润烧伤膏治疗Ⅱ度冻伤疗效观察 [J], 崔巧娜;徐桂银;叶菁;张勇5.湿润烧伤膏联合康复新液治疗肛瘘术后创面疗效观察 [J], 汪明因版权原因，仅展示原文概要，查看原文内容请购买。

羊毛角蛋白溶液在毛织物定型中的应用

羊毛角蛋白溶液在毛织物定型中的应用孙艳丽;姚金波;李博;贾书刚【摘要】采用自制的羊毛角蛋白溶液整理毛织物,通过正交试验选择合理的整理工艺参数,得到最优工艺为:羊毛角蛋白溶液用量15％(o.w.f)、处理温度75℃、处理时间60 min、浴比1∶25.对比整理前后毛织物的性能发现:毛织物毡缩率由17.85％下降到4.1％;急弹性回复角从144.2°提高到21 5°;断裂强力小幅提高而断裂伸长下降.整理后织物的毡缩率显著下降,折痕回复性提高,断裂强力增加而伸长下降,毛织物定型效果得到改善.【期刊名称】《纺织学报》【年(卷),期】2015(036)004【总页数】5页(P97-101)【关键词】定型;毡缩率;折痕回复性;力学性能【作者】孙艳丽;姚金波;李博;贾书刚【作者单位】天津工业大学纺织学院,天津300387;天津工业大学纺织学院,天津300387;天津工业大学先进纺织复合材料教育部重点实验室,天津300387;天津工业大学纺织学院,天津300387;天津工业大学纺织学院,天津300387【正文语种】中文【中图分类】TS195.5废弃羊毛中有丰富的角蛋白资源，角蛋白质大分子结构中含有大量的羧基、氨基、羟基等亲水基团，具有良好的生物亲和性、无毒及亲肤等优异的性能［1－2］。

近年来，由羊毛制取角蛋白溶液并以其为主要成分应用于纺织品整理加工的研究，已引起人们的关注［3－5］。

使用天然高分子整理剂代替传统的合成整理剂，符合纺织品绿色、生态、环保的要求，不仅可改善织物的性能，而且可得到对人体有更好亲肤性的纺织品［6－7］。

本文研究以废弃的羊毛作为原料，通过还原剂与金属盐联合法得到羊毛角蛋白溶液，并将其应用于毛织物的定型整理加工中，以改善毛织物的性能。

1 试验部分1.1 试验材料及设备材料:60支羊毛毛条;羊毛织物，平纹，经纬纱线密度均为12.5 tex×2，经纬向密度为283根/10 cm×253根/10 cm;还原剂LKS-610(天津联宽生物制剂有限公司)，亚硫酸氢钠(天津市化学试剂三厂)，溴化锂(天津市博迪化工有限公司)。

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Preparation and Properties of Keratin–Poly(vinyl alcohol) Blend FiberKazunori Katoh,1,2Mikio Shibayama,3Toshizumi Tanabe,2Kiyoshi Yamauchi21Owari Textile Research Center,Aichi Industrial Technology Institute,35,Miyaura,Mabiki,Yamato-cho, Ichinomiya-shi,Aichi,491-0931,Japan2Department of Bioapplied Chemistry,Graduate School of Engineering,Osaka City University,3-3-138,Sugimoto, Sumiyoshi-ku,Osaka,558-8585,Japan3Mikawa Textile Research Center,Aichi Industrial Technology Institute,109,Igakubo,Ohtsuka-cho,Gamagouri-shi,Aichi,443-0013,JapanReceived13August2002;accepted22May2003ABSTRACT:Keratin–poly(vinyl alcohol)(PVA)blendﬁ-bers containing13–46wt%of–SSO3ϪNaϩ(S-sulfo)keratin were prepared by the wet-spinning technique.They were formed by dehydration of an aqueous solution of S-sulfo keratin and PVA(spinning dope)in a coagulation bath of sodium sulfate–saturated solution and subsequently drawn. Keratin–PVAﬁbers showed higher tenacity than that of wool,presumably originating from the high mechanical strength of the PVA component.The heat treatment at about 200°C improved the waterproof characteristics such as shrinkage of keratin–PVAﬁbers more conspicuously than did PVAﬁbers.That is,after heat treatment at195°C for10 min,keratin–PVA blendﬁber shrank20%in water at60°C,whereas PVAﬁber shrank56%.Differential thermal analysis suggested the crosslinking of disulﬁde bonds between ker-atin molecules during the heat treatment,whereas the addi-tional crystallization of PVA component was not observed. Adsorption of heavy metal and toxic gas to keratin–PVA ﬁbers was also investigated.Keratin–PVAﬁber was found to adsorb Agϩand formaldehyde gas more efﬁciently than PVA.Thus,blends of keratin and PVA were advantageous for both polymerﬁbers.©2003Wiley Periodicals,Inc.J Appl Polym Sci91:756–762,2004Key words:keratin;poly(vinyl alcohol);ﬁbers;mechanical properties;adsorptionINTRODUCTIONFibers based on regenerated protein or protein–poly-acrylonitrile graft copolymer have been widely inves-tigated to develop new textileﬁbers and recycle the protein materials.However,proteins investigated so far have been limited to silk,zein,soy been,casein, and collagen.1–5Regenerated keratinﬁbers were never the focus of investigations because of keratin’s chem-ical feature,as described below.Keratin is the major structuralﬁbrous protein pro-viding outer coverings such as hair,wool,feathers, nail,and horns of mammals,reptiles,and birds.6From amino acid analysis,keratin is found to be character-istically abundant in cysteine residues(7–20%of the total amino acid residues).7These cysteine residues are oxidized to give both inter-and intramolecular disulﬁde bonds,which may result in the mechanically strong three-dimensionally linked network of keratin ﬁber.Therefore,the disulﬁde bond must be cleaved by reducing or oxidizing reagents for extraction of kera-tin from wool,hair,and so forth.Although various attempts have been made to ex-tract keratin from wool or hair,most of them gave keratin carrying chemically modiﬁed cysteine.8–13Ex-traction of unmodiﬁed reduced keratin solution had never been performed because cysteine residues were unstable.Recently,we reported the preparation of a stable aqueous solution of unmodiﬁed reduced kera-tin.14We extracted keratin with not only2-mercapto-ethanol but also sodium dodecyl sulfate(surfactant)to promote extraction and stabilize the keratin solution. Except for reduction with2-mercaptoethanol,sulﬁ-tolysis,6which is a kind of reducing reaction,can convert a disulﬁde bond to–SH and–SSO3ϪNaϩ(S-sulfo group)(see Fig.1).We also extracted S-sulfo keratin by sulﬁtolysis with sodium disulﬁte(Na2S2O5) and sodium dodecyl sulfate,and subsequently dried the resulting solution with a spray dryer to obtain S-sulfo keratin powder.It readily dissolves in distilled water again and appears to be easy to handle for industrial application.We attempted to develop regenerated S-sulfo kera-tinﬁber by wet spinning.However,the viscosity of aqueous S-sulfo keratin solution was too low to use in wet spinning.To overcome this problem,a polymer blend is the best choice if both components are com-patible.15The combination of PVA and S-sulfo keratin is unique in that both polymers are usually dissolvedCorrespondence to:K.Katoh(katkaz@owaritex.jp). Journal of Applied Polymer Science,Vol.91,756–762(2004)©2003Wiley Periodicals,Inc.and coagulated under essentially similar conditions.Furthermore,the obtained keratin–PVA blend ﬁber is expected to show excellent mechanical properties be-cause of high tensile strength and modulus of poly-(vinyl alcohol)(PVA)ﬁber.16Because wool is known to adsorb toxic substances such as heavy metal ion and formaldehyde gas,the keratin–PVA blend ﬁber of high S-sulfo keratin content is expected to capture much more toxic substances than PVA ﬁber.In the present study,we prepared the keratin–PVA blend ﬁber of high S-sulfo keratin content,by the wet-spinning technique,to develop a novel ﬁber and recycle wool.Furthermore,we evaluated water resis-tance and adsorption behavior of heavy metal ions and toxic gas for the keratin–PVA ﬁbers.EXPERIMENTALMaterialsUrea,sodium disulﬁte (Na 2S 2O 5),and sodium dodecyl sulfate (SDS)were purchased from Kanto Chemical Co.(Tokyo,Japan).Poly(vinyl alcohol)powder (OKS-9080N,fully saponiﬁed type;average polymerization 4000)was purchased from Nihon Gosei Kagaku Co.(Osaka,Japan).Merino wool was used in this experi-ment.Preparation of S-sulfo keratin powderA 150-g sample of wool was immersed in 1.5L of aqueous solution containing 8M urea,75g of SDS,and 150g of Na 2S 2O 5.The mixture was heated to 100°C,shaken for 30min,and then cooled in a water bath at 30°C.The resulting mixture was ﬁltered through a stain-less-steel mesh.The ﬁltrate was dialyzed against 15L of water containing 0.1wt %Na 2S 2O 5,with cellulose tub-ing (molecular weight cutoff of 12,000–14,000Da)for 6days,with a change of outer solution twice a day.The protein concentration of the dialyzate was 5wt %on average,according to the Buiret method.17Thedialyzate was condensed by rotary vacuum evapora-tor (N-11Tokyo Rikakikai Co.,Tokyo,Japan)and dried using a spray dryer (Pulvis Mini-Spray GA32,Yamato Scientiﬁc,Tokyo,Japan)to obtain S-sulfo ker-atin powder.Gel electrophoresisSDS–polyacrylamide gel electrophoresis (SDS-PAGE)was performed using a Bio-Rad Mini Protean 3Cell and 10–20%gradient gel (Bio-Rad Laboratories,Her-cules,CA).S-sulfo keratin powder was dissolved in distilled water (0.1wt %)and boiled with 2-mercap-toethanol for 3min.Reduced and unreduced S-sulfo keratins were subjected to SDS-PAGE with molecular weight marker (Precision Protein Standards,un-stained,Catalog 161-0362;Bio-Rad Laboratories)at 200V.The proteins in the developed gel were stained by Coomassie brilliant blue G-250(Bio-Rad Laborato-ries).Wet spinningFor preparation of the spinning dope,S-sulfo keratin powder was dissolved in distilled water at room tem-perature and PVA was then dissolved with stirring at about 90°C.The spinning dopes containing various amounts of S-sulfo keratin and PVA were subjected to the following wet-spinning experiment.The wet-spinning apparatus used in this work is shown in Figure 2,which consists of a syringe pump,spinneret,coagulation bath,the ﬁrst drawing roller (DR1),and the second drawing roller (DR2).The sy-ringe pump was ﬁlled with 350mL of spinning dope,which was then extruded at 3.6g/min through the stainless-steel six-hole spinneret into the coagulation bath containing 400g/L sodium sulfate aqueous so-lution.Each hole of the spinneret was 0.5mm in diameter and its capillary length was 2mm.Temper-ature and immersion length of the coagulation bath were 60°C and 1.0m,respectively.The coagulated ﬁber was withdrawn by DR1,drawn between DR1and DR2at room temperature,and ﬁnally collectedonFigure 1Breakage of disulﬁde bonds bysulﬁtolysis.Figure 2Schematic diagram of wet spinning apparatus.KERATIN–POLY(VINYL ALCOHOL)BLEND FIBER 757DR2,where the velocity of DR1was maintained at4.2m/min in all the experiments.The draw ratio wascalculated as the velocity ratio of DR2to DR1.Keratin–PVAﬁbers of various S-sulfo keratin contents werespun under maximum draw ratio.Heat treatmentThe spunﬁber readily shrank or dissolved in water.Thus,heat treatment was conducted under dry hot air(195°C)for2,4,6,8,10,and12min to evaluateshrinkage or solubility in hot water.Mechanical propertiesMechanical testing was performed using a ShimadzuAutograph AG-500A(Shimadzu Corp.,Kyoto,Japan).Gauge length and crosshead speed were100mm and100mm/min,respectively.Theﬁber was precondi-tioned for24h at20°C and65%relative humiditybefore the mechanical testing.Tenacity and elongationat break were determined as the average of10tests foreachﬁber sample,where the dimension of tenacitywas centinewton/decitex(cN/dtex).Tex has been de-ﬁned as a gram per1000m ofﬁber and corresponds toﬁber diameter.Scanning electron microscopy(SEM)Theﬁber sample was washed in ethanol and driedunder vacuum,then cross-sectionally cut and coatedwith gold under vacuum before imaging with SEM(JSM-T330scanning microscope;JEOL Co.,Tokyo,Ja-pan).The SEM micrograph provided information con-cerning surface and cross section morphology. Shrinkage in hot waterTheﬁber sample was cut to100cm in length andimmersed in distilled water at60°C for30min.Sub-sequently the length of wet sample was measuredwithout tension.The shrinking ratio was calculatedaccording to the following equation:[(L intϪL wet)/ L int]ϫ100,where L int and L wet are the length of theinitial and wetﬁber,respectively.Thermal analysisThermogravimetric analysis(TGA)and differentialthermal analysis(DTA)were carried out using aDTG-60(Shimadzu).Theﬁber sample was cut intopieces and weighed in a platinum cell.The weight lossand DTA curve were obtained by heating at10°C/min,to600°C under nitrogen.Heavy metal ion and toxic gas adsorptionA1-g sample of aﬁber was placed in a100-mL beaker, to which50mL of100ppm metal solution was added. After shaking for1h at40°C,the residual metal con-tent in the media was assayed by an atomic absorption ﬂame-emission spectrometer AA-640-13(Shimadzu). The applied heavy metal ions were Agϩand Pb2ϩ.To prepare100ppm metal solution media,each metal standard solution for atomic absorption spectrometry (1000ppm;Kanto Chemical Co.)was diluted by dis-tilled water.A1-g sample of aﬁber was placed in a5-L gas sampling bag,to which3L of25ppm formaldehyde gas was injected.After exposure at20°C for2h,the residual gas content was measured by gas detector (Kitagawa Precision Gas Detector,Komyo Co.,Tokyo, Japan).The adsorption of heavy metal ions and formalde-hyde gas to keratin–PVAﬁber was evaluated from [(C intϪC res)/C int]ϫ100,where C int and C res are the initial and the residual contents,respectively.RESULTS AND DISCUSSION Characterization of S-sulfo keratin powder Extraction of keratin from wool was carried out under mild conditions(at40–50°C for about5–10h)to avoid hydrolysis of the keratin in the solution.8–13We per-formed extraction at100°C for30min to enhance the efﬁciency of extraction.Then,the obtained solution was exposed to hot air(80–90°C)to prepare the pow-der using a spray dryer.The obtained S-sulfo keratin was subjected to SDS-PAGE analysis under bothre-Figure3SDS-PAGE of S-sulfo keratins(a)reduced by 2-mercaptoethanol at100°C for3min and(b)unreduced. The molecular weight marker is shown in the right column.758KATOH ET AL.duced and unreduced conditions (see Fig.3).Under the reduced condition,S-sulfo keratin gave two major weight fractions (60,000and 45,000Da)and a minor fraction (16,000Da).It was assumed that the two high-weight fractions originated from an ␣-helical low-sulfur component in a microﬁbril and the latter from a nonhelical high-sulfur component in a ma-trix.18Thus,S-sulfo keratin was found not to hydro-lyze during extraction and spray drying.SDS-PAGE of the unreduced S-sulfo keratin showed the higher molecular weight fraction over 250kDa,in addition to those given under reduced conditions [see Fig.3(b)].It was revealed that S-sulfo keratin still had the conﬁguration crosslinked by disulﬁde bonds.DTA and TGA curves of S-sulfo keratin and wool are shown in Figure 4.Three major endothermic peaks were observed for wool within the temperature range of 200–350°C,from which it has been interpreted that the lowest temperature peak originates from meltingor denaturation of the helical component in the micro-ﬁbril.The DTA curve of S-sulfo keratin was similar to that of wool.It was surprising that the helical confor-mation was preserved in spite of the extraction under harsh conditions such as the use of a denaturing re-agent and high temperature.The weight losses of both S-sulfo keratin and wool started at about 200°C and continued to about 400°C.Spei et al.19reported that the endothermic peak of wool and hair around 230–245°C was attributed to helical denaturation superim-posed by various decomposition reactions.Production of keratin–PVA blend fiberThe viscosity of S-sulfo keratin aqueous solutions (5–10wt %)was so low that they readily dispersed in the coagulation bath after extrusion from the spinne-ret.To increase the viscosity of S-sulfo keratin solu-tion,PVA was added to the solution.The viscous spinning dope (10–20poise)could be prepared by dissolving 6–7wt %of PVA.The combination of PVA and S-sulfo keratin is unique in that both polymers are usually dissolved and coagulated under essentially similar conditions.As a result,keratin–PVA ﬁber with 13–46wt %of keratin content could be spun.Table I summarizes the mechanical properties of keratin–PVA and PVA ﬁbers spun under the maximum draw ratio.Keratin–PVA ﬁbers showed higher tenacity than that of wool,which was presumably attributed to high mechanical strength of the PVA component.When the S-sulfo keratin content increased to 45.5wt %,keratin–PVA ﬁber became more fragile than wool.From these results,maximum S-sulfo keratin content was deter-mined to be 30wt %.Figure 5shows an SEM micrograph of keratin–PVA ﬁber with 30wt %of S-sulfo keratin,which reveals a rough cross section and surface morphology of the ﬁber.In particular,a “skin–core”structure was ob-served at cross section.It has been believed that the surface skin layer is formed by rapidcoagulation,Figure 4DTA and TGA curves of S-sulfo keratin (solid line)and wool (dotted line).TABLE IMechanical Properties of Keratin–PVA Fibers Containing Various Amounts of S-Sulfo KeratinFiberaContent of S-sulfo keratin b (%)Tenacity c(cN/dtex)Elongation at break c (%)Keratin–PVA (1:7)d 12.5 1.57Ϯ0.0941.1Ϯ6.4Keratin–PVA (3:7)d 30.0 1.49Ϯ0.1622.1Ϯ4.4Keratin–PVA (5:6)d 45.50.77Ϯ0.0612.6Ϯ3.2PVA (0:10)d 0.0 1.45Ϯ0.1644.5Ϯ3.5Wool—1.06e38ea Spun under 60°C of coagulation temperature and maximum draw ratio:3.40for keratin–PVA ﬁber and 2.73for PVA ﬁber.bCalculated from the concentration of S-sulfo keratin and PVA in the spinning dope.cThe data represent means ϮSD of 10measurements.dEach concentration of S-sulfo keratin and PVA in the spinning dope is shown in parentheses.For example,Keratin–PVA (1:7)was spun from the aqueous dope of S-sulfo keratin (1wt %)and PVA (7wt %).eFrom Gillespie.26KERATIN–POLY(VINYL ALCOHOL)BLEND FIBER 759whereas the inner porous core is formed by delayed coagulation,which proceeds under the disturbance of the surface skin.16The rough surface and skin–core cross section may affect the mechanical properties.However,it is known that the uniformity of the ﬁber morphology is given by the use of the coagulation bath of lower temperature to delay coagulation.16Ac-tually,the smooth morphology was observed for the ﬁber spun at 40°C (see Fig.6).Waterproof characteristicsPVA ﬁbers,which are spun by wet spinning,are sol-uble in water.Keratin–PVA ﬁbers also readily shrank or dissolved in water because S-sulfo keratin as well as PVA was a water-soluble component.The heat treat-ment is known to improve waterproof properties,such as solubility and shrinkage of PVA ﬁbers.20The most important change that occurred during the heat treatment is an increase of the crystallinity of PVA through the removal of residual water and the forma-tion of new hydrogen bonds between the molecules.21We also treated keratin–PVA and PVA ﬁbers under dry air of 195°C,changing the treating time to im-prove their waterproof characteristics after the ﬁbers were spun at 60°C of the coagulation temperature and drawn under maximum draw ratio.Although Sakurada et al.16conducted the heat treatment of PVA over 200°C,we adopted a slightly lower temperature because S-sulfo keratin showed a weight loss above 200°C on TGA analysis (see Fig.4).After heat treatment,the shrinkage of the ﬁber was measured in water at 60°C.The results are shown in Table II.The shrinkage of keratin–PVA ﬁber signiﬁ-cantly decreased as heat treatment time increased,whereas that of PVA ﬁber was about 50–60%regard-less of the length of heat treatment time.These results showed that the heat treatment was obviously effec-tive for keratin–PVA ﬁber rather than PVA ﬁber.The heat treatment for more than 10min turned the color of keratin–PVA ﬁber from white to yellow probably because of the thermal decomposition of S-sulfo ker-atin.Thermal analysis was conducted to evaluate the effect of heat treatment on keratin–PVA ﬁber.Figure 7shows DTA and TGA curves of keratin–PVA ﬁber heat-treated for 8min and untreated ﬁber,in which two major endothermic curves were observed.The peak at higher temperature (ϳ260°C)was shifted to the lower temperature by 4°C and its area slightly increased after heat treatment.The lower-temperature peak (ϳ230°C)was unchanged before and after the heat treatment,although it was attributed to melting of the PVA component.22It was assumed thattheFigure 5SEM micrograph of keratin–PVA ﬁber spun at a coagulation temperature of 60°C and draw ratio of3.40.Figure 6SEM micrograph of keratin–PVA ﬁber spun at a coagulation temperature of 40°C and draw ratio of 3.40.TABLE IIWaterproof Characteristics of Keratin–PVA and PVA Fibers Heat-Treated at 195°C for Various TimesTime of heat treatment (min)Shrinkage in hot water at 60°C a (%)Keratin–PVA ﬁber bPVA ﬁber b0ND c ND c 2ND c ND c 460ND c 644ND c 8406010205612852aDeﬁned as (L int ϪL wet )/L int ϫ100,where L int and L wet are the length of the ﬁber before and after immersion in water (60°C).bSpun under 60°C of coagulation temperature and max-imum draw ratio:3.40for keratin–PVA ﬁber and 2.73for PVA ﬁber.cNot determined because ﬁber dissolved in water.760KATOH ET AL.additional crystallization of PVA did not occur during the heat treatment.Therefore,PVA ﬁbers were thought to shrink heavily in hot water in spite of the heat treatment as mentioned above.The heat treat-ment at 195°C was likely insufﬁcient for PVA compo-nent.The heat treatment at the same temperature de-creased the shrinkage of keratin–PVA ﬁber in hot water.Reduced keratin carried instable SH and S-sulfo groups that easily formed disulﬁde bonds and crosslinked intra-and intermolecular bonds.In the thermal analysis of hair,cystine decomposition (i.e.,disulﬁde bond decomposition)was reported to occur in the temperature range of 250–255°C.19Therefore,it could be presumed that the change of endothermic peak (ϳ257°C)was attributed to decomposition of disulﬁde bonds (see Fig.7),which formed during the heat treatment.Disulﬁde bond formation might have prevented keratin–PVA ﬁber from shrinking in hot water.Heavy metal ion and toxic gas adsorptionSeveral researchers have reported the interaction of various heavy metal ions with wool.Speakman et al.23ﬁrst reported the binding of mercury compounds to wool.Miyamoto et al.24reported that the keratin gel showed very high uptake of heavy metal ions.Toxic gases such as formaldehyde are also known to adsorb onto wool.We evaluated the adsorption of Ag ϩ,Pb 2ϩ,and formaldehyde gas onto the heat-treated keratin–PVA ﬁber prepared as mentioned above.The results are summarized in Table III.Keratin–PVA ﬁber ad-sorbed Ag ϩbut PVA ﬁber did not,indicating thatS-sulfo keratin efﬁciently captured Ag ϩ.It was sug-gested that the keratin molecule had the binding site for Ag ϩ.Pb 2ϩwas signiﬁcantly adsorbed by PVA ﬁber as well as keratin–PVA ﬁber;thus it remained unclear whether S-sulfo-keratin adsorbed Pb 2ϩ.Shindo and Brown 25showed that Pb 2ϩwould also form a 1:1complex with the cysteine residue (Cys)similarly to Hg 2ϩ.Formaldehyde gas was adsorbed by keratin–PVA ﬁber more efﬁciently than PVA,similarly to Ag ϩ.CONCLUSIONSS-sulfo keratin was extracted from wool by reducing disulﬁde bonds with Na 2S 2O 5,and its powder was prepared by drying the S-sulfo keratin aqueous solu-tion using a spray dryer.From SDS-PAGE analysis,the S-sulfo keratin seemed not to degrade during ex-traction and spray drying.Furthermore,DTA showed that helical conformation of keratin molecules was preserved during the extraction under harsh condi-tions such as chemical and heat treatment.Keratin–poly(vinyl alcohol)(PVA)blend ﬁbers were prepared by the wet-spinning technique,in the S-sulfo keratin content range of 13–46wt %.Judging from the mechanical properties of keratin–PVA ﬁbers spun un-der the maximum draw ratio,maximum S-sulfo ker-atin content was determined to be 30wt %and its ﬁber was stronger than wool.The heat treatment was use-ful to improve the waterproof characteristics of kera-tin–PVA blend ﬁber rather than PVA ﬁber alone.From DTA and TGA analysis,the additional crystallization of the PVA component did not occur.However,the endothermic peak at 257°C suggested the formation of disulﬁde bonds of keratin molecules during heat treat-ment.Adsorption of heavy metal and toxic gas to keratin–PVA ﬁbers was also investigated.Pb 2ϩ,Ag ϩ,and formaldehyde gas were signiﬁcantly adsorbed by keratin–PVA ﬁber.In particular,keratin–PVAﬁberFigure 7DTA and TGA curves of keratin–PVA ﬁbers (solid line)heat-treated at 195°C for 8min and (dotted line)un-treated.Before the heat treatment,keratin–PVA ﬁbers were spun at a coagulation temperature of 60°C and draw ratio of 3.40.TABLE IIIAdsorption of Heavy Metal Ions and ToxicGas to Keratin–PVA Fiber aFiberHeavy metal ion (%)Toxic gas (%)Ag ϩPb 2ϩFormaldehydeKeratin–PVA ﬁber b 40.588.348.0PVA ﬁber b2.786.728.0aAdsorption was evaluated by the percentage of ad-sorbed fraction,which was deﬁned as (C int ϪC res )/C int ϫ100,where C int and C res are the initial and residual con-tents,respectively.bSpun under 60°C of coagulation temperature and max-imum draw ratio:3.40for keratin–PVA ﬁber and 2.73for PVA ﬁber.Fibers were further heat-treated at 195°C for 8min.KERATIN–POLY(VINYL ALCOHOL)BLEND FIBER 761was found to adsorb Agϩand formaldehyde more efﬁciently than PVA did.Thus,the combination of S-sulfo keratin and PVA was advantageous for both polymerﬁbers in terms of the mechanical properties,waterproof characteristics, and the adsorption for toxic substances.PVAﬁber has been used for various industrial applications such as rope,ﬁsh net,hose,ﬁber-reinforced conveyer belts, and so on because of its high strength.16We expect that keratin–PVAﬁbers will also be widely used for industrial applications,especially as absorbents for the toxic substances such as heavy metal ions and form-aldehyde gas.References1.Matsumoto,K.;Uejima,H.;Iwasaki,T.;Sano,Y.;Sumino,H.J Appl Polym Sci1996,60,503.2.Yang.,Y.;Wang,L.;Li,S.J Appl Polym 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