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   5166篇
  免费   273篇
  国内免费   22篇
耳鼻咽喉   86篇
儿科学   286篇
妇产科学   35篇
基础医学   478篇
口腔科学   102篇
临床医学   400篇
内科学   1348篇
皮肤病学   59篇
神经病学   345篇
特种医学   141篇
外科学   837篇
综合类   137篇
一般理论   1篇
预防医学   215篇
眼科学   235篇
药学   397篇
中国医学   18篇
肿瘤学   341篇
  2023年   57篇
  2022年   95篇
  2021年   240篇
  2020年   87篇
  2019年   155篇
  2018年   248篇
  2017年   134篇
  2016年   156篇
  2015年   148篇
  2014年   247篇
  2013年   322篇
  2012年   457篇
  2011年   454篇
  2010年   238篇
  2009年   183篇
  2008年   275篇
  2007年   326篇
  2006年   318篇
  2005年   245篇
  2004年   213篇
  2003年   165篇
  2002年   137篇
  2001年   37篇
  2000年   41篇
  1999年   24篇
  1998年   27篇
  1997年   17篇
  1995年   17篇
  1992年   18篇
  1991年   12篇
  1990年   11篇
  1989年   15篇
  1988年   19篇
  1987年   19篇
  1986年   15篇
  1985年   23篇
  1984年   15篇
  1983年   16篇
  1979年   20篇
  1978年   13篇
  1977年   17篇
  1975年   15篇
  1974年   11篇
  1973年   16篇
  1972年   12篇
  1971年   13篇
  1969年   12篇
  1968年   19篇
  1967年   14篇
  1966年   10篇
排序方式: 共有5461条查询结果,搜索用时 15 毫秒
21.
Extracts of plants have been widely evaluated for possible antiproliferative and anticarcinogenic properties. The antiproliferative activity of ethanolic extract of Boerhaavia diffusa, a plant used in traditional medicine, was evaluated in several cells. It inhibited T cell mitogen phytohemagglutinin and concanavalin A-stimulated proliferation of human peripheral blood mononuclear cells (PBMC). It also inhibited purified protein derivative antigen-stimulated PBMC proliferation and human mixed lymphocyte culture. In addition, B. diffusa extract inhibited the growth of several cell lines of mouse and human origin, such as mouse macrophage cells (RAW 264.7), human macrophage cells (U937), human monocytic cells (THP-1), mouse fibroblast cells (L929), human embryonic kidney cells (HEK293), mouse liver cells (BNLCL.2), African green monkey kidney cells (COS-1), mouse lymphoma cells (EL-4), human erythroleukemic cells (K562), and human T cells (Jurkat). The present study has demonstrated the antiproliferative potential of ethanolic extract of B. diffusa in vitro.  相似文献   
22.
The rabbit model of tuberculosis has been used historically to differentiate between Mycobacterium tuberculosis and Mycobacterium bovis based on their relative virulence in this animal host. M. tuberculosis infection in market rabbits is cleared over time, whereas infection with M. bovis results in chronic, progressive, cavitary disease leading to death. Because of the innate resistance of commercial rabbits to M. tuberculosis, 320 to 1,890 log-phase, actively growing inhaled bacilli were required to form one grossly visible pulmonary tubercle at 5 weeks. The range of inhaled doses required to make one tubercle allows us to determine the relative pathogenicities of different strains. Fewer inhaled organisms of the M. tuberculosis Erdman strain were required than of M. tuberculosis H37Rv to produce a visible lesion at 5 weeks. Furthermore, with the Erdman strain, only 7 of 15 rabbits had healed lesions at 16 to 18 weeks; among the other animals, two had chronic, progressive cavitary disease, a phenotype usually seen only with M. bovis infection. Genotypic investigation of the Erdman strain with an H37Rv-based microarray identified gene differences in the RD6 region. Southern blot and PCR structural genetic analysis showed significant differences between M. tuberculosis strains in this region. Correlation of the relative pathogenicity, including disease severity, in the rabbit model with the strain genotype may help identify stage-specific M. tuberculosis genes important in human disease.  相似文献   
23.
The performance of a rapid particle agglutination test for human immunodeficiency virus (HIV) (Capillus HIV type 1 [HIV-1]/HIV-2) on hospital samples is compared with enzyme-linked immunosorbent assays. The test had a sensitivity and specificity of 99 and 98.9%, respectively. In addition, the test was reactive on plasma samples from all individuals infected with HIV-1 subtype C. This test can safely be used for voluntary counseling and testing in India.  相似文献   
24.
We describe the clinicopathological and immunohistochemical findings in five cases of sclerosing stromal tumours of ovary and compare our findings with other reported cases of this uncommon tumour and with fibromas and thecomas which they may mimic.  相似文献   
25.
26.
27.
We examined the acute stress response associated with having to deliver either bad or good medical news using a simulated physician–patient scenario. Twenty-five healthy medical students were randomly assigned to a bad medical news (BN), a good medical news (GN), or a control group that read magazines during the session. Self-report measures were obtained before and after the task. Blood pressure and heart rate were measured throughout the task period. Four blood samples were obtained across the task period. The BN and GN tasks produced significant increases in self-reported distress and cardiovascular responses compared with the control group. There was also a significant increase in natural killer cell function 10 min into the task in the BN group compared with the control group. The BN task was also somewhat more stressful than the GN task, as shown by the self-report and cardiovascular data. These findings suggest that a simulated physician–patient scenario produces an acute stress response in the physician, with the delivery of bad medical news more stressful than the delivery of good medical news.  相似文献   
28.
One important application of DNA microarray technology is the simultaneous analysis of gene expression of different mRNAs. Comparison of mRNA patterns of diseased and healthy tissue may help to understand the pathogenesis of a given disorder. In cancer tissue, identified dysregulated genes may serve as new molecular markers for diagnosis or prognosis or may ideally serve as new targets for therapy. Using membrane cDNA array technology, we analyzed gene expression in human melanomas, one of the most aggressive types of cancer with a high metastatic potential and with markedly increased incidence worldwide. To account for the heterogeneity of tumors, we compared total RNA from cutaneous melanoma metastases of 10 different patients with primary human melanocytes. An abundance of genes was dysregulated (up-/downregulated), which involved for example the apoptosis gene growth factor receptor-bound protein 10, Bcl2-associated X membrane protein, Bcl2 antagonist of cell death, glutathione S-transferase theta(1) and glutathione reductase. Ultimately, the identification of melanoma-associated genes may provide a potential therapeutic strategy for identifying and targeting malignant melanoma.  相似文献   
29.
30.
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