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   49413篇
  免费   3882篇
  国内免费   111篇
耳鼻咽喉   468篇
儿科学   1833篇
妇产科学   1299篇
基础医学   6150篇
口腔科学   442篇
临床医学   6333篇
内科学   8939篇
皮肤病学   1000篇
神经病学   5004篇
特种医学   1017篇
外科学   5269篇
综合类   402篇
现状与发展   1篇
一般理论   86篇
预防医学   6973篇
眼科学   848篇
药学   3444篇
中国医学   60篇
肿瘤学   3838篇
  2024年   57篇
  2023年   512篇
  2022年   814篇
  2021年   1819篇
  2020年   1106篇
  2019年   1801篇
  2018年   1905篇
  2017年   1465篇
  2016年   1554篇
  2015年   1629篇
  2014年   2298篇
  2013年   3006篇
  2012年   4493篇
  2011年   4426篇
  2010年   2416篇
  2009年   1997篇
  2008年   3465篇
  2007年   3409篇
  2006年   3167篇
  2005年   2973篇
  2004年   2577篇
  2003年   2154篇
  2002年   1877篇
  2001年   224篇
  2000年   147篇
  1999年   230篇
  1998年   306篇
  1997年   225篇
  1996年   180篇
  1995年   163篇
  1994年   119篇
  1993年   100篇
  1992年   80篇
  1991年   56篇
  1990年   56篇
  1989年   59篇
  1988年   39篇
  1987年   33篇
  1986年   29篇
  1985年   31篇
  1984年   50篇
  1983年   39篇
  1982年   20篇
  1981年   22篇
  1980年   26篇
  1978年   31篇
  1976年   19篇
  1975年   22篇
  1973年   24篇
  1972年   18篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
AIDS and Behavior - We previously demonstrated that village community mobilization (CM) was associated with reduced HIV incidence among adolescent girls and young women (AGYW) in South Africa....  相似文献   
994.
AIDS and Behavior - Social biases may influence providers’ judgments related to pre-exposure prophylaxis (PrEP) and patients’ consequent PrEP access. US primary and HIV care providers...  相似文献   
995.
AIDS and Behavior - Despite growing availability, HIV pre-exposure prophylaxis (PrEP) uptake and adherence remains suboptimal among female sex workers (FSW) in the United States. Using...  相似文献   
996.
AIDS and Behavior - The timeline followback (TLFB) takes more resources to collect than the Alcohol Use Disorder Identification Test (AUDIT-C). We assessed agreement of TLFB and AUDIT-C with the...  相似文献   
997.
998.
999.
In chronic immune thrombocytopenic purpura (ITP), autoantibodies bind to platelet surface proteins, particularly alphaIIb, resulting in platelet destruction by the reticulo-endothelial system. In order to better localize the autoepitopes on alphaIIb, we studied the binding of antibodies to Chinese hamster ovary (CHO) cells expressing either alphaIIbbeta3 or alphaIIb-alphavbeta3 chimaeras in which a segment of alphaIIb (either amino acids L1-Q459, L1-F223 or F223-Q459) was substituted for that portion of alphav. We evaluated platelet-associated autoantibodies from 14 ITP patients with alphaIIb-dependent antibodies. Ten of 14 bound to alphaIIb (L1-Q459)-alphavbeta3, showing that autoepitopes were often localized to this region of alphaIIb. In addition, each of the autoantibodies binding to alphaIIb (L1-Q459)-alphavbeta3, also bound to CHO cells expressing either alphaIIb(L1-F223)-alphavbeta3 or alphaIIb(F223-Q459)-alphavbeta3). In two of the three eluates tested, > 95% of the autoantibody binding to alphaIIb could be adsorbed using CHO cells expressing any of the three chimaeras, showing that the epitope(s) have contact points on either side of amino acid F223; in the third eluate, only a portion ( approximately 40%) could be adsorbed by the chimaeric cell lines showing that, in this patient, an additional antibody was also present, directed to a site distal to amino acid Q459. The remaining four eluates bound to CHO cells expressing alphaIIbbeta3 but to none of the chimaeras, suggesting that these epitopes are also distal to amino acid Q459. We conclude that the binding of many anti-alphaIIbbeta3 autoantibodies is dependent on the presence of alphaIIb amino acids L1-Q459.  相似文献   
1000.
Oesophageal candidiasis is an epithelial infection which requires an immune deficiency. C. albicans is commonly the cause, although other species may also be responsible. Resistance to fluconazole, drug of choice for treatment, is an emerging problem. The objectives of the current paper were: to determine the frequency of oesophageal candidiasis in patients submitted to upper gastrointestinal endoscopy, analyze risk factors, identify Candida species and determine in vitro susceptibility to fluconazole. During 12 months, 34 patients with oesophageal candidiasis were detected. Out of 1.230 HIV negative and 91 HIV positive patients submitted to upper endoscopy, 11 (0.9%) and 23 (25.3%), respectively, had candidiasis. Risk factors for HIV negative patients were systemic antibiotic therapy in 2, deficient dental cleaning in 2 aged patients, use of proton pump inhibitors in 3, inhaled steroids in 2, malignancy in 1 and oral steroids in 1. The histopathologic diagnosis was confirmed in 48.6% of cases. Cultures were positive in 91.2% C. albicans was prevalent (93.5%), and was associated to other species in 5 cases (16.1%), (3 C. glabrata, 1 C. tropicalis and 1 C. parapsilosis). One case cultured only C. glabrata and 1, only C tropicalis. Out of 31 cultures, 25 were susceptible to fluconazole, 4 dose dependent (1 C. albicans, 3 C. glabrata), and 2 resistant (1 C. albicans, 1 C. glabrata). Frequency of oesophageal candidiasis was low, except for HIV positive patients. The most common etiologic agent was C. albicans, though other Candida species were also found. C. albicans and C. glabrata showed dose dependency and resistance to fluconazole.  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