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   149854篇
  免费   10468篇
  国内免费   762篇
耳鼻咽喉   1401篇
儿科学   3860篇
妇产科学   2739篇
基础医学   20010篇
口腔科学   3448篇
临床医学   14531篇
内科学   32041篇
皮肤病学   2874篇
神经病学   14519篇
特种医学   6097篇
外国民族医学   6篇
外科学   22858篇
综合类   1888篇
现状与发展   2篇
一般理论   139篇
预防医学   10752篇
眼科学   3165篇
药学   10426篇
中国医学   244篇
肿瘤学   10084篇
  2023年   744篇
  2022年   490篇
  2021年   2484篇
  2020年   1956篇
  2019年   2816篇
  2018年   3426篇
  2017年   2663篇
  2016年   3045篇
  2015年   3512篇
  2014年   5031篇
  2013年   6800篇
  2012年   10518篇
  2011年   11138篇
  2010年   6349篇
  2009年   6044篇
  2008年   10196篇
  2007年   10879篇
  2006年   10349篇
  2005年   10595篇
  2004年   9983篇
  2003年   9465篇
  2002年   8860篇
  2001年   1453篇
  2000年   1043篇
  1999年   1443篇
  1998年   1751篇
  1997年   1361篇
  1996年   1120篇
  1995年   1250篇
  1994年   1106篇
  1993年   1077篇
  1992年   755篇
  1991年   775篇
  1990年   602篇
  1989年   584篇
  1988年   546篇
  1987年   558篇
  1986年   494篇
  1985年   526篇
  1984年   621篇
  1983年   547篇
  1982年   753篇
  1981年   687篇
  1980年   588篇
  1979年   350篇
  1978年   365篇
  1977年   393篇
  1976年   327篇
  1975年   284篇
  1974年   250篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Die Anaesthesiologie - Der Postpunktionskopfschmerz („postdural puncture headache“, PDPH) zählt zu den wesentlichen Komplikationen der peripartalen neuroaxialen Analgesie. Als...  相似文献   
2.

Background

Survival in cancer patients is associated with a multitude of biological, social, and psychological factors. Although it is well established that all these factors add to overall mortality, it is not well understood how the predictive power of these parameters changes in a comprehensive model and over time.

Methods

Patients who attended the authors’ outpatient clinic were invited to participate. The authors followed 5180 mixed cancer patients (51.1% female; mean age, 59.1 years [SD = 13.8]) for up to 16 years and analyzed biological (age, sex, cancer site, anemia), psychological (anxiety, depression), and social variables (marital status, education, employment status) potentially predicting overall survival in a Cox proportional hazards model.

Results

The median survival time for the entire sample was 4.3 years (95% confidence interval, 4.0–4.7). The overall survival probabilities for 1 and 10 years were 76.8% and 38.0%, respectively. Following an empirical approach, the authors split the time interval into five periods: acute, subacute, short-term, medium-term, and long-term. A complex pattern of variables predicted overall survival differently in the five periods. Biological parameters were important throughout most of the time, social parameters were either time-independent predictors or tended to be more important in the longer term. Of the psychological parameters, only depression was a significant predictor and lost its predictive power in the long-term.

Conclusions

The findings of this study allow the development of comprehensive patient-specific models of risk and resilience factors addressing biopsychosocial needs of cancer patients, paving the way for a personalized treatment plan that goes beyond biomedical cancer care.  相似文献   
3.
4.
The widely accepted Cytokine Milieu Hypothesis proposes that the cytokine milieu, in which antigen activates CD4 T cells, from a non-T cell source, primarily determines the Th subset to which the ensuing effector Th cells belong. We focus on the generation of Th1 and Th2 cells. We briefly restate the grounds for the Threshold Hypothesis we favour for how the Th1/Th2 phenotype of a response is primarily determined: tentative and robust thresholds of antigen-mediated CD4 T cell interactions lead to the generation of Th1 and Th2 cells. The component antigens of pathogens are present in different amounts. It is expected, within the context of the threshold mechanism that, although there is often an initial predominance of Th1 or Th2 cells, some Th cells of the opposing type are initially generated. An initially somewhat heterogeneous Th response is known to become with time more ‘coherent’ in its Th1/Th2 phenotype. I propose The Cytokine Implementation Hypothesis as a mechanism for how coherence is achieved. Most cytokines made by Th cells of one subset tend to facilitate the further generation of Th cells of this subset and/or inhibit the generation of Th cells of opposing subsets, accounting for how coherence may be achieved. Many observations on which The Cytokine Milieu Hypothesis is based are accounted for by this alternative hypothesis. We outline predictions of the new hypothesis and discuss the importance of coherence of immune responses for their efficacy in protecting against foreign invaders.  相似文献   
5.
6.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Akteure der öffentlichen Gesundheit (Public Health) tragen wesentlich zu Gesundheitsschutz, -förderung und...  相似文献   
7.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Die Aussage, dass Suizide zu 90 % Folge psychischer Erkrankungen sind, wird häufig in der wissenschaftlichen Literatur...  相似文献   
8.
9.
10.
The set of guidelines for good clinical research practice in pharmacodynamic studies of neuromuscular blocking agents was developed following an international consensus conference in Copenhagen in 1996 (Viby-Mogensen et al., Acta Anaesthesiol Scand 1996, 40 , 59–74); the guidelines were later revised and updated following the second consensus conference in Stockholm in 2005 (Fuchs-Buder et al., Acta Anaesthesiol Scand 2007, 51 , 789–808). In view of new devices and further development of monitoring technologies that emerged since then, (e.g., electromyography, three-dimensional acceleromyography, kinemyography) as well as novel compounds (e.g., sugammadex) a review and update of these recommendations became necessary. The intent of these revised guidelines is to continue to help clinical researchers to conduct high-quality work and advance the field by enhancing the standards, consistency, and comparability of clinical studies. There is growing awareness of the importance of consensus-based reporting standards in clinical trials and observational studies. Such global initiatives are necessary in order to minimize heterogeneous and inadequate data reporting and to improve clarity and comparability between different studies and study cohorts. Variations in definitions of endpoints or outcome variables can introduce confusion and difficulties in interpretation of data, but more importantly, it may preclude building of an adequate body of evidence to achieve reliable conclusions and recommendations. Clinical research in neuromuscular pharmacology and physiology is no exception.  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