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   110980篇
  免费   4882篇
  国内免费   572篇
耳鼻咽喉   1754篇
儿科学   6320篇
妇产科学   2541篇
基础医学   9674篇
口腔科学   4044篇
临床医学   7712篇
内科学   25518篇
皮肤病学   3323篇
神经病学   7438篇
特种医学   5280篇
外科学   24132篇
综合类   1894篇
预防医学   5849篇
眼科学   2241篇
药学   4889篇
  2篇
中国医学   707篇
肿瘤学   3116篇
  2023年   3457篇
  2022年   4151篇
  2021年   5691篇
  2020年   4304篇
  2019年   11509篇
  2018年   8630篇
  2017年   4240篇
  2016年   1296篇
  2015年   1916篇
  2014年   2530篇
  2013年   1242篇
  2012年   786篇
  2011年   4214篇
  2010年   1179篇
  2009年   1606篇
  2008年   1690篇
  2007年   1193篇
  2006年   984篇
  2005年   1517篇
  2004年   1558篇
  2003年   1060篇
  2002年   1620篇
  2001年   1962篇
  2000年   3002篇
  1999年   3348篇
  1998年   3132篇
  1997年   2135篇
  1996年   1420篇
  1995年   981篇
  1994年   1015篇
  1993年   692篇
  1992年   741篇
  1991年   606篇
  1990年   642篇
  1989年   446篇
  1988年   498篇
  1987年   312篇
  1985年   2760篇
  1984年   4043篇
  1983年   2887篇
  1982年   2838篇
  1981年   2675篇
  1980年   2364篇
  1979年   2191篇
  1978年   1804篇
  1977年   1565篇
  1976年   1691篇
  1975年   1437篇
  1974年   1266篇
  1973年   1201篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
《Vaccine》2020,38(33):5337-5342
Freezing of alum-based vaccines drastically alters their colloidal composition and leads to irreversible cluster formation. The loss of stability is well described, but the impact of frost damage on the functionality of the induced and secreted antibody repertoire has not been studied in detail. We therefore applied our single-cell measurement platform to extract the frequencies of Immunoglobulin G-secreting cells in combination with individual secretion rates and affinities. We showed that, frost-damaged or not, the tested vaccine was able to generate similar frequencies of total and antigen-affine IgG-secreting cells. Additionally, the frost-damaged vaccine stimulated a similar T-cell cytokine secretion pattern when compared to the regularly stored vaccine. However, frost-damaged vaccines induced no efficient affinity maturation and a complete collapse of the affinity distribution was observed. This study unveiled the impact of frost-damage to alum-based vaccines on the induced secreted antibody repertoire, and illustrated the power of functional single-antibody analysis.  相似文献   
83.
84.
85.
86.
The past decade has been a time of great change for US physicians. Many physicians feel that the care delivery system has become a barrier to providing high-quality care rather than facilitating it. Although physician distress and some of the contributing factors are now widely recognized, much of the distress physicians are experiencing is related to insidious issues affecting the cultures of our profession, our health care organizations, and the health care delivery system. Culture refers to the shared and fundamental beliefs of a group that are so widely accepted that they are implicit and often no longer recognized. When challenges with culture arise, they almost always relate to a problem with a subcomponent of the culture even as the larger culture does many things well. In this perspective, we consider the role of culture in many of the problems facing our health care delivery system and contributing to the high prevalence of professional burnout plaguing US physicians. A framework, drawn from the field of organizational science, to address these issues and heal our professional culture is considered.  相似文献   
87.
88.
BackgroundWomen suffering from kidney disease are more prone to fertility problems, due to uremia. Fortunately, their fertility rate increases dramatically after renal transplantation. This study analyzes the predictors/risk factors of successful pregnancy with live birth outcome while presenting an overview of the 7-year experience of a single center.MethodsThis retrospective cohort study includes 239 women of reproductive age (18–40 years) who underwent renal transplantation in a tertiary Turkish clinic between October 1, 2011, and August 24, 2017. The subjects were invited to take part in a survey questioning their obstetric characteristics and they were assessed in 2 groups: fertile and infertile. Multivariable linear regression analysis was conducted to determine the predictors of a successful pregnancy.ResultsThirty-five 35 patients wished to become pregnant: 12 got pregnant spontaneously, while 21 failed to become pregnant (spontaneously). The mean age of the patients at the survey was 34 ± 7. Regular menstrual cycles after renal transplantation, tacrolimus-mycophenolate mofetil maintenance protocol, and age at transplantation were found to be predictors of spontaneous pregnancy. The duration of peritoneal dialysis was significantly longer in the infertile group (48 vs 12 months).ConclusionEnd-stage renal disease's negative impacts, including menstrual abnormality and fertility problems, can be overcome by successful kidney transplantation with appropriate immunosuppression. Minimizing the duration of peritoneal dialysis, particularly in patients who desire future fertility, may be accepted as a logical management strategy.  相似文献   
89.
90.
Accurately predicting the hepatic clearance of compounds using in vitro to in vivo extrapolation (IVIVE) is crucial within the pharmaceutical industry. However, several groups have recently highlighted the serious error in the process. Although empirical or regression-based scaling factors may be used to mitigate the common underprediction, they provide unsatisfying solutions because the reasoning behind the underlying error has yet to be determined. One previously noted trend was intrinsic clearance-dependent underprediction, highlighting the limitations of current in vitro systems. When applying these generated in vitro intrinsic clearance values during drug development and making first-in-human dose predictions for new chemical entities though, hepatic clearance is the parameter that must be estimated using a model of hepatic disposition, such as the well-stirred model. Here, we examine error across hepatic clearance ranges and find a similar hepatic clearance-dependent trend, with high clearance compounds not predicted to be so, demonstrating another gap in the field.  相似文献   
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