首页 | 官方网站   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   122298篇
  免费   47075篇
  国内免费   260篇
医药卫生   169633篇
  2024年   67篇
  2023年   628篇
  2022年   709篇
  2021年   3600篇
  2020年   6284篇
  2019年   12234篇
  2018年   11765篇
  2017年   12724篇
  2016年   13521篇
  2015年   13543篇
  2014年   13971篇
  2013年   15077篇
  2012年   8388篇
  2011年   8312篇
  2010年   11073篇
  2009年   7114篇
  2008年   5276篇
  2007年   4129篇
  2006年   3842篇
  2005年   3349篇
  2004年   3159篇
  2003年   2889篇
  2002年   2765篇
  2001年   971篇
  2000年   839篇
  1999年   487篇
  1998年   354篇
  1997年   299篇
  1996年   206篇
  1995年   197篇
  1994年   192篇
  1993年   150篇
  1992年   109篇
  1991年   91篇
  1990年   71篇
  1989年   83篇
  1988年   79篇
  1987年   67篇
  1986年   67篇
  1985年   60篇
  1984年   82篇
  1983年   69篇
  1982年   80篇
  1981年   69篇
  1980年   67篇
  1979年   31篇
  1978年   37篇
  1977年   36篇
  1976年   29篇
  1973年   22篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
91.
92.
Abstract

Aim: Competency-based medical education aims to foster mastery goals in learners. We examined medical students’ mastery approach (beneficial) and mastery avoidance (maladaptive) goals and their associations with students’ basic psychological needs, self-compassion, and self-efficacy.

Methods: This was a cross-sectional study employing an online questionnaire. Two hundred medical students in all four years of the medical program completed the questionnaire, containing measures of mastery goals, basic psychological needs (autonomy, competence, relatedness), self-compassion, and self-efficacy. Regression analyses were performed.

Results: Of the three basic psychological needs, the need for competence was significant in explaining both types of mastery goals. Self-efficacy and self-compassion were significant in explaining mastery approach and mastery avoidance goals, respectively.

Conclusions: Creating learning environments that are supportive of students’ need for competence, raising students’ awareness of the value of learning from mistakes in competency acquisition, and providing opportunities for students to experience self-efficacy may foster beneficial mastery approach goals in medical students.  相似文献   
93.
Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette‐Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune‐enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.  相似文献   
94.
Melatonin receptors play important roles in the regulation of circadian and seasonal rhythms, sleep, retinal functions, the immune system, depression, and type 2 diabetes development. Melatonin receptors are approved drug targets for insomnia, non‐24‐hour sleep‐wake disorders, and major depressive disorders. In mammals, two melatonin receptors (MTRs) exist, MT1 and MT2, belonging to the G protein‐coupled receptor (GPCR) superfamily. Similar to most other GPCRs, reliable antibodies recognizing melatonin receptors proved to be difficult to obtain. Here, we describe the development of the first monoclonal antibodies (mABs) for mouse MT1 and MT2. Purified antibodies were extensively characterized for specific reactivity with mouse, rat, and human MT1 and MT2 by Western blot, immunoprecipitation, immunofluorescence, and proximity ligation assay. Several mABs were specific for either mouse MT1 or MT2. None of the mABs cross‐reacted with rat MTRs, and some were able to react with human MTRs. The specificity of the selected mABs was validated by immunofluorescence microscopy in three established locations (retina, suprachiasmatic nuclei, pituitary gland) for MTR expression in mice using MTR‐KO mice as control. MT2 expression was not detected in mouse insulinoma MIN6 cells or pancreatic beta‐cells. Collectively, we report the first monoclonal antibodies recognizing recombinant and native mouse melatonin receptors that will be valuable tools for future studies.  相似文献   
95.
96.
97.
98.
The recognition that neurogenesis does not stop with adolescence has spun off research towards the reduction of brain disorders by enhancing brain regeneration. Adult neurogenesis is one of the tougher problems of developmental biology as it requires the generation of complex intracellular and pericellular anatomies, amidst the danger of neuroinflammation. We here review how a multitude of regulatory pathways optimized for early neurogenesis has to be revamped into a new choreography of time dependencies. Distinct pathways need to be regulated, ranging from neural growth factor induced differentiation to mitochondrial bioenergetics, reactive oxygen metabolism, and apoptosis. Requiring much Gibbs energy consumption, brain depends on aerobic energy metabolism, hence on mitochondrial activity. Mitochondrial fission and fusion, movement and perhaps even mitoptosis, thereby come into play. All these network processes are interlinked and involve a plethora of molecules. We recommend a deep thinking approach to adult neurobiology.  相似文献   
99.
100.
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-23

京公网安备 11010802026262号