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   264025篇
  免费   23778篇
  国内免费   15996篇
耳鼻咽喉   2429篇
儿科学   3326篇
妇产科学   5144篇
基础医学   30509篇
口腔科学   4963篇
临床医学   33404篇
内科学   41298篇
皮肤病学   3064篇
神经病学   14428篇
特种医学   9487篇
外国民族医学   103篇
外科学   28597篇
综合类   39946篇
现状与发展   58篇
一般理论   51篇
预防医学   16786篇
眼科学   7183篇
药学   27335篇
  206篇
中国医学   13552篇
肿瘤学   21930篇
  2024年   543篇
  2023年   3572篇
  2022年   6014篇
  2021年   13032篇
  2020年   9705篇
  2019年   8449篇
  2018年   8966篇
  2017年   8023篇
  2016年   7569篇
  2015年   11422篇
  2014年   14349篇
  2013年   13681篇
  2012年   19977篇
  2011年   21849篇
  2010年   13584篇
  2009年   10941篇
  2008年   14443篇
  2007年   14349篇
  2006年   13742篇
  2005年   13553篇
  2004年   9478篇
  2003年   8402篇
  2002年   7299篇
  2001年   6437篇
  2000年   6399篇
  1999年   6632篇
  1998年   3779篇
  1997年   3749篇
  1996年   2856篇
  1995年   2658篇
  1994年   2306篇
  1993年   1549篇
  1992年   2324篇
  1991年   2024篇
  1990年   1693篇
  1989年   1469篇
  1988年   1275篇
  1987年   1171篇
  1986年   948篇
  1985年   766篇
  1984年   499篇
  1983年   383篇
  1982年   226篇
  1981年   207篇
  1980年   191篇
  1979年   245篇
  1978年   141篇
  1977年   112篇
  1976年   98篇
  1974年   116篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
miRNAs是一类长度约为20~25个核苷酸,参与基因调控表达的内源性非编码RNA。miR-149作为miRNAs的重要成员,在多种肿瘤中表达异常,其表达水平与肿瘤细胞增殖、转移、凋亡、耐药、患者的早期诊断及预后密切相关。因此,miR-149有望成为新一类抗肿瘤治疗的靶点。  相似文献   
32.
33.
34.
35.
36.
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   
37.
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   
38.
39.
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   
40.
Wang  Di  Tao  Xiaogen  Fei  Mingming  Chen  Jian  Guo  Wei  Li  Ping  Wang  Jinquan 《Journal of neurovirology》2020,26(3):442-448

Pseudorabies virus (PRV) primarily infects swine but can infect cattle, dogs, and cats. Several studies have reported that PRV can cross the specie barrier and induce human encephalitis, but a definitive diagnosis of human PRV encephalitis is debatable due to the lack of PRV DNA detection. Here, we report a case of human PRV encephalitis diagnosed by the next-generation sequencing (NGS) of PRV sequences in the cerebrospinal fluid (CSF) of a patient. A male pork vendor developed fever and seizures for 6 days. NGS results showed PRV sequences in his CSF and blood. Sanger sequencing showed that PRV DNA in the CSF and PRV antibodies in both the CSF and blood were positive. MRI results revealed multiple inflammatory lesions in the bilateral hemisphere. Based on the clinical and laboratory data, we diagnosed the patient with PRV encephalitis. This case suggests that PRV can infect humans, causing severe viral encephalitis. People at risk of PRV infection should improve their self-protection awareness.

  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