首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1099篇
  免费   88篇
  国内免费   28篇
儿科学   61篇
妇产科学   21篇
基础医学   110篇
口腔科学   48篇
临床医学   118篇
内科学   199篇
皮肤病学   13篇
神经病学   41篇
特种医学   254篇
外科学   103篇
综合类   19篇
预防医学   108篇
眼科学   4篇
药学   60篇
中国医学   1篇
肿瘤学   55篇
  2023年   2篇
  2022年   2篇
  2021年   8篇
  2020年   2篇
  2019年   10篇
  2018年   24篇
  2017年   9篇
  2016年   16篇
  2015年   20篇
  2014年   25篇
  2013年   27篇
  2012年   27篇
  2011年   39篇
  2010年   40篇
  2009年   36篇
  2008年   31篇
  2007年   41篇
  2006年   42篇
  2005年   24篇
  2004年   20篇
  2003年   29篇
  2002年   21篇
  2001年   16篇
  2000年   21篇
  1999年   19篇
  1998年   61篇
  1997年   73篇
  1996年   79篇
  1995年   47篇
  1994年   40篇
  1993年   45篇
  1992年   19篇
  1991年   14篇
  1990年   19篇
  1989年   40篇
  1988年   40篇
  1987年   30篇
  1986年   31篇
  1985年   31篇
  1984年   8篇
  1983年   10篇
  1982年   12篇
  1981年   10篇
  1980年   12篇
  1979年   3篇
  1978年   4篇
  1977年   13篇
  1976年   10篇
  1975年   6篇
  1891年   1篇
排序方式: 共有1215条查询结果,搜索用时 0 毫秒
31.
The HTLV-I tax gene protein (Tax) is not packaged within the mature viral particle from which the proteins for the commercially available enzyme-linked immunosorbent assay (ELISA) are derived. Screening of 162 individuals within a cohort of white intravenous (IV) drug abusers, previously identified as having an increased incidence of HTLV-I infection, demonstrated that seven of them had antibodies to the HTLV-I Tax protein but tested negative in HTLV-I ELISAs and Western blots prepared from purified virion proteins. Three out of 35 individuals in other behaviorally defined high-risk groups also displayed this limited pattern of reactivity to HTLV-I proteins. The presence of the anti-HTLV- I p40/Tax antibodies was determined by radioimmunoprecipitation assay (RIPA), which also revealed low levels of anti-env reactivity. The specificity of the anti-p40 reactivity was confirmed on specific Tax ELISAs and Western blots prepared from recombinantly produced Tax. In vitro gene amplification by the polymerase chain reaction (PCR) was used to establish the presence of sequences homologous to HTLV-I proviral DNA in four/four of these HTLV-I ELISA negative, Tax ELISA/Tax western blot/RIPA positive individuals. These data suggest that the true incidence of HTLV-I infection within high-risk cohorts is greater than previously reported.  相似文献   
32.
Birth weight, childhood growth and abdominal obesity in adult life.   总被引:4,自引:0,他引:4  
OBJECTIVE: To examine the relationship of adult abdominal obesity to birth weight, childhood growth and lifetime socioeconomic circumstances. METHODS: A cohort of 3200 men and women with measured waist and hip circumference, height and weight at age 43 who have been followed since their birth in March 1946 in England, Scotland and Wales. Regression models were used to examine mean waist-hip ratio and waist circumference in relation to prospective measures of birth weight, weight relative to height in childhood at ages 4, 7, 11 and 15 and adult body mass index, and to test the independent and interactive nature of the associations and adjust for childhood and adult social class. RESULTS: There was a small inverse effect of birth weight on waist-hip ratio (P=0.037) but not waist circumference in women, after adjustment for current body size. Relative weight at age 7 was inversely related to waist-hip ratio and waist circumference in men (P<0.001 for both) and waist circumference in women (P=0.007) after adjustment for current body size. These relationships were attenuated in men of large body mass index (P<0.01 for interactions between relative weight at 7 y and body mass index in both cases) but were not modified by birth weight. Relative weights at other ages showed similar patterns to those observed at age 7, the effect being weakest at age 4. These findings were independent of lifetime socioeconomic circumstances. CONCLUSION: This study found a small prenatal inverse effect of fetal growth on adult waist-hip ratio due to a reduced hip size. There was also an inverse postnatal effect of childhood growth such that for any given adult body size those who had been lighter in childhood were more at risk of abdominal obesity. These relationships were independent of childhood socioeconomic circumstances and support the idea that insulin resistance may be linked to low weight in childhood.  相似文献   
33.
34.
35.
36.
IntroductionWith the emergence of the COVID-19 pandemic, all elective surgery was temporarily suspended in the UK, allowing for diversion of resource to manage the anticipated surge of critically unwell patients. Continuing to deliver time-critical surgical care is important to avoid excess morbidity and mortality from pathologies unrelated to COVID-19. We describe the implementation and short-term surgical outcomes from a system to deliver time-critical elective surgical care to patients during the COVID-19 pandemic.Materials and methodsA protocol for the prioritisation and safe delivery of time-critical surgery at a COVID-19 ‘clean’ site was implemented at the Nuffield Health Exeter Hospital, an independent sector hospital in the southwest of England. Outcomes to 30 days postoperatively were recorded, including unplanned admissions after daycase surgery, readmissions and complications, as well as the incidence of perioperative COVID-19 infection in patients and staff.ResultsA total of 128 surgical procedures were performed during a 31-day period by a range of specialties including breast, plastics, urology, gynaecology, vascular and cardiology. There was one unplanned admission and and two readmissions. Six complications were identified, and all were Clavien-Dindo grade 1 or 2. All 128 patients had preoperative COVID-19 swabs, one of which was positive and the patient had their surgery delayed. Ten patients were tested for COVID-19 postoperatively, with none testing positive.ConclusionThis study has demonstrated the implementation of a safe system for delivery of time-critical elective surgical care at a COVID-19 clean site. Other healthcare providers may benefit from implementation of similar methodology as hospitals plan to restart elective surgery.  相似文献   
37.
38.
39.
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号