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   1566056篇
  免费   134223篇
  国内免费   20432篇
耳鼻咽喉   18772篇
儿科学   45889篇
妇产科学   41192篇
基础医学   210185篇
口腔科学   40304篇
临床医学   150545篇
内科学   315273篇
皮肤病学   34486篇
神经病学   123210篇
特种医学   63654篇
外国民族医学   369篇
外科学   235309篇
综合类   65115篇
现状与发展   50篇
一般理论   455篇
预防医学   121004篇
眼科学   34528篇
药学   116967篇
  169篇
中国医学   13019篇
肿瘤学   90216篇
  2021年   19702篇
  2020年   13464篇
  2019年   16384篇
  2018年   21099篇
  2017年   17390篇
  2016年   19222篇
  2015年   24047篇
  2014年   32216篇
  2013年   41168篇
  2012年   53117篇
  2011年   57476篇
  2010年   35731篇
  2009年   32940篇
  2008年   48563篇
  2007年   51039篇
  2006年   51705篇
  2005年   50480篇
  2004年   44925篇
  2003年   43094篇
  2002年   40116篇
  2001年   71207篇
  2000年   73232篇
  1999年   62342篇
  1998年   20190篇
  1997年   18527篇
  1996年   18679篇
  1995年   18696篇
  1994年   17222篇
  1993年   15585篇
  1992年   49062篇
  1991年   47446篇
  1990年   45389篇
  1989年   43032篇
  1988年   39795篇
  1987年   39031篇
  1986年   36597篇
  1985年   35257篇
  1984年   26747篇
  1983年   22421篇
  1982年   14039篇
  1981年   12616篇
  1979年   23745篇
  1978年   17185篇
  1977年   14474篇
  1976年   13260篇
  1975年   13795篇
  1974年   16196篇
  1973年   15482篇
  1972年   14236篇
  1971年   13106篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
61.
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   
62.
63.
64.
65.
66.
67.
BackgroundDual antiplatelet therapy (DAPT) is the cornerstone treatment of acute myocardial infarction (AMI).ObjectiveThe present study aimed to investigate the efficacy and safety of triple antiplatelet therapy (TAPT) in elderly female patients with diabetes and ST segment elevation myocardial infarction (STEMI), who had undergone percutaneous coronary intervention (PCI).MethodsWe designed a randomized, single-blind study. Control group A (97 elderly male patients with diabetes and STEMI, whose CRUSADE scores were < 30) received aspirin, ticagrelor, and tirofiban. A total of 162 elderly female patients with diabetes and STEMI were randomly divided into two groups according to CRUSADE score. Group B (69 patients with CRUSADE score > 31) received aspirin and ticagrelor. Group C (93 patients with CRUSADE score < 30) received aspirin, ticagrelor and tirofiban. P values < 0.05 were considered statistically significant.ResultsCompared to the findings in group A, post-PCI Thrombolysis in Myocardial Infarction (TIMI) grade 3 blood flow and TIMI myocardial perfusion grade 3 were significantly less prevalent in group B (p < 0.05). When compared to groups A and C, the incidence of major adverse complications was significantly higher in group B (p < 0.05).ConclusionTAPT could effectively reduce the incidence of major complications in elderly female patients with diabetes and STEMI. However, close attention should be paid to hemorrhage in patients receiving TAPT. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)  相似文献   
68.
69.
70.
目的以基因表达数据集资料为研究对象,分析BCAN基因在肾透明细胞癌中的表达情况以及对患者预后的影响。方法在Oncomine数据库中挖掘BCAN在肾透明细胞癌(ccRCC)中的表达情况。从TCGA数据库中获取ccRCC患者临床资料和目的基因的表达信息并进行统计分析。利用GEO数据库中GSE73731数据集的ccRCC样本进行基因富集分析。利用String数据库分析与BCAN相关的蛋白。结果BCAN低表达组的ccRCC患者在病理分期及T分期方面低于高表达组(P<0.001;P=0.001);N分期及M分期差异无统计学意义(P>0.05)。BCAN低表达组患者的总生存期优于高表达组(P=0.033)。BCAN基因高表达组的样本主要富集在KRAS信号通路。结论BCAN可以通过多种途径来促进肿瘤细胞的侵袭能力,有望成为ccRCC不良预后的重要生物标志物之一。  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