英语写作复习

必背摘要：
Example(Non-structured):
DPC4/Smad4:No Mutations, Rare Allelic Imbalances, and Retained Protein Expression in Pancreatic Endocrine Tumors
(Diag Mol Pathol 2003;12:181-186)
Several chromosomal loci involved in tumorigenesis of pancreatic endocrine tumors (PET) have been identified. To date, the only gene known to be frequently altered is the MEN1 gene. Recently,DPC4 mutations and homozygous deletions have been described in 5/9(55%) non-functioning PET, thus representing the most frequent genetic aberration described in PET. However, these data are in accordance with comparative genomic hybridization (CGH) results that rarely show genetic losses on chromosome 18.They have also been challenged by immunohistochemical data. We performed a detailed combined DPC4 mutation and deletion analysis in 34 benign and malignant PET. Mutations of the conserved C-terminal exons were not found in all examined PET and allelic loss (LOH) was found to be rare (‹6%) by combined microsatellite PCR and FISH analysis. In addition, DPC4 protein expression was retained in all PET that were examined by immnuohistochemistry. Therefore, DPC4 inactivation by mutation or deletion appears to be very rare in PET, which confirms the current concept of unrelated mechanisms of tumorigenesis of endocrine versus exocrine pancreatic tumors.
Example(Full-structured):JAMA. 1999;281:2289-2293.
Relationship of Ascorbic Acid to Blood Lead Levels
Context Some animal studies suggest that orally administered ascorbic acid may chelate lead and decrease the risk of the toxic effects of lead. However, results from several small studies in humans have yielded in conclusive evidence of a beneficial effect of ascorbic acid on lead toxicity.
Objective To examine the relationship between serum ascorbic acid levels and prevalence of elevated blood lead levels.
Design, Setting, and Participants Cross-sectional analysis of a probability sample of the US population enrolled in the Third National Health and Nutrition Examination Survey, 1988-1994 (4213 youths aged 6-16 years and 15,365 adults aged 17 years)without a history of lead poisoning.
Main Outcome Measures Elevated and log blood lead levels by serum ascorbic acid level.
Results A total of 22youths (0.5%) and 57 adults (0.4%) had elevated blood lead levels (defined as 0.72 µmol/L [15 µg/dL]) and 0.97 µmol/L [20 µg/dL], respectively). After controlling for the effects of age, race, sex, income level, and dietary energy, fat, calcium, iron, and zinc intake, youths in the highest serum ascorbic acid tertile had an 89% decreased prevalence of elevated blood lead levels compared with youths in the lowest serum ascorbic acid tertile (odds ratio, 0.11; 95% confidence interval, 0.04-0.35; P for trend=.002). Adults in the highest 2 serum ascorbic acid tertiles had a 65% to 68% decreased prevalence of elevated blood lead levels compared with adults
in the lowest serum ascorbic acid tertile (P for trend=.03). As a continuous predictor, serum ascorbic acid level was independently associated with decreased log blood lead levels among adults (P<.001), but not among youths (P=.14).
Conclusions Our data suggest that high serum levels of ascorbic acid are independently associated with a decreased prevalence of elevated blood lead levels. If these associations are related causally, ascorbic acid intake may have public health implications for control of lead toxicity.
Example(Semi-structured):
Purine-Rich Foods, Dairy and Protein Intake, and the Risk of Gout in Men (New England Journal of Medicine V olume 350:1093-1103 V olume 350:1093-1103) ABSTRACT
Background Various purine-rich foods and high protein intake have long been thought to be risk factors for gout. Similarly, the possibility that the consumption of dairy products has a role in protecting against gout has been raised by metabolic studies. We prospectively investigated the association of these dietary factors with new cases of gout.
Methods Over a 12-year period,we prospectively examined the relationship between purported dietary risk factors and new cases of gout among 47,150 men who had no history of gout at base line. We used a supplementary questionnaire to ascertain whether participants met the American College of Rheumatology survey criteria for gout. Diet was assessed every four years by means of a food-frequency questionnaire.
Results During the 12 years of the study, we documented 730 confirmed new cases of gout. The multivariate relative risk of gout among men in the highest quintile五分位of meat intake, as compared with those in the lowest quintile, was 1.41 (95 percent confidence interval, 1.07 to 1.86; P for trend = 0.02), and the corresponding relative risk associated with seafood intake was 1.51 (95 percent confidence interval, 1.17 to 1.95; P for trend = 0.02). In contrast, the incidence of gout decreased with increasing intake of dairy products; the multivariate relative risk among men in the highest quintile, as compared with those in the lowest quintile, was 0.56 (95 percent confidence interval, 0.42 to 0.74; P for trend <0.001). The level of consumption of purine-rich vegetables and the total protein intake were not associated with an increased risk of gout.
Conclusions Higher levels of meat and seafood consumption are associated with an increased risk of gout, whereas a higher level of consumption of dairy products is associated with a decreased risk. Moderate intake of purine-rich vegetables or protein is not associated with an increased risk of gout.
Example (Semi-structured)
Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study
(The Lancet 2001; 358:1500-03)
Summary
Background Dietary vitamin D supplementation is associated with reduced risk of
type1 diabetes in animals. Our aim was to ascertain whether or not vitamin D supplementation or deficiency in infancy could affect development of type 1 diabetes.
Methods A birth-cohort study was done, in which all pregnant women (n=12055) in Oulu and Lapland, northern Finland, who were due to give birth in 1966 were enrolled. Data was collected in the first year of life about frequency and dose of vitamin D supplementation and presence of suspected rickets. Our primary outcome measure was diagnosis of type 1 diabetes by end of December, 1997. Findings12058 0f 12231 represented live births, and 10821 (91% of those alive) children were followed-up at age 1 year. Of the 10366 children included in analyses, 81 were diagnosed with diabetes during the study. Vitamin D supplementation was associated with a decreased frequency of type 1 diabetes when adjusted for neonatal, anthropometric, and social characteristics (rate ratio [RR] for regular vs no supplementation 0.12, 95% CI 0.03-0.51, and irregular vs no supplementation 0.16, 0.04-0.74. Children who regularly took the recommended dose of vitamin D (2000 IU daily)had a RR of 0.22 (0.05-0.89) compared with those who regularly received less than the recommended amount. Children suspected of having rickets during the first year of life had a RR of 3.0(1.0-9.0) compared with those without such a suspicion.
Interpretation Dietary vitamin D supplementation is associated with reduced risk of type 1 diabetes. Ensuring adequate vitamin D supplementation for infants could help to reverse the increasing trend in the incidence of type 1 diabetes.
时态使用：
1)present tense and/or present perfect tense used in CONTEXT/BACKGROUND
一般现在时和现在完成时用于背景句。

2）present tense used when the subject is the paper, and past tense in case of the purpose of this study (infinitive is also acceptable)in OBJECTIVE/AIM/PURPOSE 现在完成时用于主语是文章，过去时态用于研究的目的，也可用不定式。

3）past tense or past perfect tense used in METHODS/RESULTS
一般过去时或过去完成时用于方法和结果。

4）present tense or, if needed, future tense used in CONCLUSION(S) 一般现在时或将来时态用于结论。

Context/Background
背景句用法：
1)…has not been fully explored (extensively studied)
2)…It is not clear that…
3)…has been well studied, but …is unknown( remains uncertain, unclear)
4)…There have been no reports to date of …
5)…There has been no evidence of…
6)…Few investigations include…
7)…has a high incidence of…, but no …data are available on…(but data are limited on…)
8)Although cryptococcosis has been associated with birds for almost 50 years, point sources for infection have not been identified…
9)Pulmonary hypertension is a …disease for which no treatment has been proved effective in a randomized trial.
10)The continuing debate over the deeply controversial issue of…has been complicated by confusion about…
11)Although several approaches have been suggested to overcome these problems, no study has clearly shown benefits of …
12)Little is known of…
13)Previous studies have reported small increases in the prevalence of…. However, …has not been determined( …are lacking/ there has been no systematic investigation of)
14)…are found in….,but ….have yet to be reported.
15)Recent years have seen rapid development in the field of…. Interest in the…has led to a growing attention to the study of…
Purpose/Objective/Aim
目的句子：
1) The purpose of this study was to…
2) In an attempt to see …, ….were made…
3) To investigate…, we assessed…
4) The aim of this study was to identify and describe…
5) The experiment was performed to…
6) The primary objective of this study was to
7) The study was designed to…
8)The intention of this study was to…
9)The experiment on…was made to (was aimed at obtaining…)
10)The purpose of this paper is to…
11)The present paper is an attempt to study…
12)This article deals with…
13)This article makes a retrospective survey of the studies of…This paper makes a critical review on…
14)Based on…, the present article gives a comparative study of…
15)The paper reports a survey of…
16)This paper attempts to make a sample study of…
Methods方法：
1)The present study was carried out by using…
2)Using an immunofluorescent technique, we…
3)…was studied (examined, diagnosed, investigated…) by the use of/
by the method of/by measurement of/by in vivo microscopy
4)The . . . model was established (set up) by . . . Methods
5)Sections of . . . were prepared as before /as previously described.
6). . . were ( was) measured (determined, detected, evaluated, assessed) by (using. . . ). . .
7)Assessment of experiments was carried out by analyzing. . .
8). . . was used to determine the statistical significance of differences between groups…
9)Patients were randomly selected. . .
10)Patients were eligible for inclusion in the . . . if they had evidence of . . . /Patients were included in our study if they had presented with. . .
11)Patients meeting the following criteria were included in the study.
12). . . subjects were recruited ( included, entered)on a voluntary basis
13)All included subjects were examined with. . .
14)Patients were divided into . . . groups. . .
15). . . groups were selected at random. . . /. . . were randomly assigned to. . . groups/. . . were randomized into . . . by a computerized system
16). . . were conducted in agreement with. . /the research procedure was carried out in accordance with. . .
17)All procedures complied with the guiding principles for the care and use of animals approved by. . .
18)All participants gave written informed consent.
19)…was isolated by the procedure of…; …was prepared according to the methods described by…;…was carried out as previously described; …was separated by the technique previously;…was done with a modified method of…
20)…samples of ⋯were obtained/taken from…;…was fixed with/ in…; …was stained with …
21)...was embedded in/ with…
22)...was dehydrated by/ in…
23)...was sectioned at a thickness of …
24)...was sliced into 1 mm sections…
25)...was cut on a ⋯ultra microtome into (在超薄切片机上切成)
26)...a 45 - year - old patient/ a patient aged 45 (years) / a patient at 45 years of age/ a patient at the age of 45 years (old) ;
27)...a patient more than the age of 45 years; older than 45 years; more than 45 years of age; patient s aged (45±3) years; 45 years of age older; a patient under/ before/ below/ less than/ after the age of 45 (years); 45 years of age and under/ or less ; less
than/ younger than 45 years;
28)...patients ranged in age from 45 to 50/ had an age range of 45 to 55 year/ with a mean (average) age of (45 ±3) years
29)...male-to-female ratio/ with female–male ratio of 2∶1
30)... was diagnosed as/ by/according to/ on the basis of ; was misdiagnosed as/ was mistaken as (for); was suspected as/ of having ⋯
31)…was treated on an outpatient/ inpatient basis; was referred/ transferred to …Results结果句：
1)We found that…
2)…was found to be…
3)…was strongly(negatively, inversely) associated with/correlated with/related to
4)…studies showed an inverse relation between…and…
5)…was found in association with…
6)Seven patients regained a mean of 5 Kg increase in weight.
7)Nine patients had an increment of …
8)Vaccine…yielded an estimated 72% reduction in hospitalization…
9)These findings indicate that . . . and are consistent with previous result.
10)The mean value of . . . was statistically increased in patients with. . . (disease) compared to the control group . . .
11)The composition of . . . was significantly different in the two groups, but . . . was similar.
12)These results support the hypothesis that . . . /These findings lend support to the hypotheses . . .
13)The results of . . . in the present study were in accordance with. . .
15) A number of differences between these previous studies and the present design may help explain the conflicting results.
16) once/ 1-fold; twice/ 2-fold; three times; two or three times; twice as much as; increased ( decreased) by 3 fold/ times; A was 3 fold/ times as…as B; was decreased/ was reduced/dropped/lowered/ declined by/ to; with an overall increase of ; with a mean/ average increase of; the ratio of A to B
17) was equal to; …of A was similar/ analogous to that/ those of B
18) was compared to/ with ; was consistent/ comparable with ; in contrast/ on the contrary/whereas
Conclusion(s)结论句：
We suggest (conclude, recommend, propose)that…
It is concluded that…
The findings suggest (indicate, demonstrate, reveal, show, confirm, provide evidence) that…
Our observations may have potential implications for. . .
The findings strongly suggest that. . .
Past tense in the section of Results, but present tense in the section of Conclusion: data/ results show/ suggest/ demonstrate/ confirm/ indicate
may/ might/ can/ could/probably/ presumably/ should
(not) appear to/ seem to/ It is likely (unlikely) that/ there is (no) evidence that/ may prove (to be)
There was highly significant difference in ⋯between A and B. …no significant/ insignificant difference was found/ observed/ noted in …between A and B.
We found no clear relationship between . . . and . . .
We found a marked difference between . . . and . . .
. . . . was highly associated with. . .
The difference was not statistically significant.
There was a significant/weak /negative/positive correlation between . . . and . . . /Positive/negative correlation was found between. . . and. . .
be of great/ some/ little/ no clinical significance in ⋯/ be of great/ little/ no limited use/ application/ value in ⋯
support/ fail to support the idea (theory/ proposal/ hypothesis/findings of previous studies) that ; supply/ offer a basis fo
pose a challenge to ;
are consistent/ in accord/ with the theory/ proposal/ hypothesis/ previous studies that be similar to that reported/ described/ documented by
be contrasted with/ different from
...may be caused by ; may lead to/ result in/ account for/ be the cause/ result of ;be responsible for ; be due to ; contribute to ; give riseto
Further work may be needed to definitely determine. . . /Further study is needed to establish. . .
In the future, we will extend the present studies to . . .
The study has several weaknesses still. Further studies are needed to answer these questions
...remains to be proved ; needs to be further investigated/ examined/ studied/ assessed/ evaluated ; remains to be uncertain。