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   880420篇
  免费   71887篇
  国内免费   1871篇
耳鼻咽喉   13438篇
儿科学   25058篇
妇产科学   26781篇
基础医学   126887篇
口腔科学   26335篇
临床医学   75909篇
内科学   167797篇
皮肤病学   17592篇
神经病学   71890篇
特种医学   35445篇
外国民族医学   171篇
外科学   137983篇
综合类   24666篇
现状与发展   2篇
一般理论   263篇
预防医学   68201篇
眼科学   21449篇
药学   66986篇
中国医学   1620篇
肿瘤学   45705篇
  2018年   7679篇
  2015年   8010篇
  2014年   11563篇
  2013年   17347篇
  2012年   23479篇
  2011年   24724篇
  2010年   14312篇
  2009年   13304篇
  2008年   23122篇
  2007年   25349篇
  2006年   25286篇
  2005年   24895篇
  2004年   24539篇
  2003年   23638篇
  2002年   22600篇
  2001年   36364篇
  2000年   36995篇
  1999年   31340篇
  1998年   9356篇
  1997年   8571篇
  1996年   8511篇
  1995年   8030篇
  1994年   7742篇
  1992年   26955篇
  1991年   26348篇
  1990年   25905篇
  1989年   25002篇
  1988年   23574篇
  1987年   23241篇
  1986年   22094篇
  1985年   21459篇
  1984年   16663篇
  1983年   14184篇
  1982年   8942篇
  1981年   8283篇
  1980年   7748篇
  1979年   17159篇
  1978年   12373篇
  1977年   10385篇
  1976年   9524篇
  1975年   10432篇
  1974年   13064篇
  1973年   12528篇
  1972年   11881篇
  1971年   11032篇
  1970年   10519篇
  1969年   10240篇
  1968年   9198篇
  1967年   8449篇
  1966年   7881篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
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   
24.
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   
25.
26.
27.
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   

28.
29.
30.
Quality of Life Research - The aim of the study was to assess QoL and identify and analyse its determinants in women with endometriosis. The study was performed in 2019 in health centres in Lublin...  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