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   891837篇
  免费   74093篇
  国内免费   2245篇
耳鼻咽喉   13142篇
儿科学   25596篇
妇产科学   25674篇
基础医学   128689篇
口腔科学   25984篇
临床医学   78180篇
内科学   170997篇
皮肤病学   17715篇
神经病学   72437篇
特种医学   36423篇
外国民族医学   187篇
外科学   139879篇
综合类   25843篇
现状与发展   3篇
一般理论   265篇
预防医学   69190篇
眼科学   21167篇
药学   67059篇
  5篇
中国医学   2202篇
肿瘤学   47538篇
  2018年   8332篇
  2015年   8601篇
  2014年   12207篇
  2013年   18229篇
  2012年   24797篇
  2011年   25890篇
  2010年   15156篇
  2009年   14123篇
  2008年   24103篇
  2007年   26190篇
  2006年   26012篇
  2005年   25564篇
  2004年   24956篇
  2003年   24040篇
  2002年   23061篇
  2001年   36868篇
  2000年   37488篇
  1999年   31833篇
  1998年   9542篇
  1997年   8831篇
  1996年   8726篇
  1995年   8212篇
  1994年   7916篇
  1992年   27145篇
  1991年   26570篇
  1990年   26063篇
  1989年   25088篇
  1988年   23652篇
  1987年   23239篇
  1986年   22090篇
  1985年   21441篇
  1984年   16591篇
  1983年   14125篇
  1982年   8936篇
  1981年   8256篇
  1980年   7707篇
  1979年   16894篇
  1978年   12181篇
  1977年   10256篇
  1976年   9400篇
  1975年   10205篇
  1974年   12737篇
  1973年   12214篇
  1972年   11642篇
  1971年   10747篇
  1970年   10286篇
  1969年   9995篇
  1968年   8976篇
  1967年   8288篇
  1966年   7706篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
21.
22.
23.
24.
25.
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.  相似文献   
26.
Analyzing functional species’ characteristics (species traits) that represent physiological, life history and morphological characteristics of species help understanding the impacts of various stressors on aquatic communities at field conditions. This research aimed to study the combined effects of pesticides and other environmental factors (temperature, dissolved oxygen, dissolved organic carbon, floating macrophytes cover, phosphate, nitrite, and nitrate) on the trait modality distribution of aquatic macrofauna communities. To this purpose, a field inventory was performed in a flower bulb growing area of the Netherlands with significant variation in pesticides pressures. Macrofauna community composition, water chemistry parameters and pesticide concentrations in ditches next to flower bulb fields were determined. Trait modalities of nine traits (feeding mode, respiration mode, locomotion type, resistance form, reproduction mode, life stage, voltinism, saprobity, maximum body size) likely to indicate pesticides impacts were analyzed. According to a redundancy analysis, phosphate -and not pesticides- constituted the main factor structuring the trait modality distribution of aquatic macrofauna. The functional composition could be ascribed for 2–4 % to pesticides, and for 3–11 % to phosphate. The lack of trait responses to pesticides may indicate that species may have used alternative strategies to adapt to ambient pesticides stress. Biomass of animals exhibiting trait modalities related to feeding by predation and grazing, presence of diapause form or dormancy, reproduction by free clutches and ovoviviparity, life stage of larvae and pupa, was negatively correlated to the concentration of phosphate. Hence, despite the high pesticide pollution in the area, variation in nutrient-related stressors seems to be the dominant driver of the functional composition of aquatic macrofauna assembly in agricultural ditches.  相似文献   
27.
28.
29.
30.
Background: Poor anger regulation is considered a risk factor of aggression in individuals with mild or borderline intellectual disabilities. Psychomotor therapy (PMT) targets anger regulation through body- and movement-oriented interventions. This study aims to inform practitioners on efficacy and research-base of PMT in this population.

Method: This systematic review evaluated nine studies which met inclusion criteria in terms of participants, intervention procedures, outcomes and certainty of evidence.

Results: Seven studies revealed a substantial reduction of aggressive behaviour or anger. Certainty of evidence was rated inconclusive in most cases due to absence of experimental control.

Conclusions: We can conclude that body-oriented PMT, involving progressive relaxation and meditation procedure “Soles of the Feet”, is a promising approach. However, the paucity of studies and methodological limitations preclude classifying it as an evidence-based practice. This suggests stronger methodological research and research aimed at PMT’s mechanisms of action (e.g., improved interoceptive awareness) is warranted.  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