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   2670篇
  免费   276篇
  国内免费   8篇
耳鼻咽喉   14篇
儿科学   61篇
妇产科学   60篇
基础医学   464篇
口腔科学   62篇
临床医学   270篇
内科学   448篇
皮肤病学   87篇
神经病学   474篇
特种医学   107篇
外科学   270篇
综合类   10篇
一般理论   2篇
预防医学   197篇
眼科学   52篇
药学   169篇
中国医学   7篇
肿瘤学   200篇
  2024年   1篇
  2023年   28篇
  2022年   42篇
  2021年   77篇
  2020年   78篇
  2019年   88篇
  2018年   100篇
  2017年   97篇
  2016年   108篇
  2015年   116篇
  2014年   162篇
  2013年   155篇
  2012年   268篇
  2011年   268篇
  2010年   137篇
  2009年   142篇
  2008年   161篇
  2007年   169篇
  2006年   159篇
  2005年   131篇
  2004年   123篇
  2003年   123篇
  2002年   94篇
  2001年   16篇
  2000年   14篇
  1999年   21篇
  1998年   13篇
  1997年   14篇
  1996年   10篇
  1995年   11篇
  1994年   10篇
  1993年   3篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1975年   1篇
  1969年   1篇
  1956年   1篇
  1939年   1篇
  1931年   1篇
排序方式: 共有2954条查询结果,搜索用时 15 毫秒
21.
We report molecular evidence of Tula virus infection in an immunocompetent patient from Germany who had typical signs of hantavirus disease. Accumulating evidence indicates that Tula virus infection, although often considered nonpathogenic, represents a threat to human health.  相似文献   
22.
23.
24.
OBJECTIVE: To acquire data on pediatric nosocomial infections (NIs), which are associated with substantial morbidity and mortality and for which data are scarce. DESIGN: Prevalence survey and evaluation of a new comorbidity index. SETTING: Seven Swiss pediatric hospitals. PATIENTS: Those hospitalized for at least 24 hours in a medical, surgical, intensive care, or intermediate care ward. RESULTS: Thirty-five NIs were observed among 520 patients (6.7%; range per hospital, 1.4% to 11.8%). Bacteremia was most frequent (2.5 per 100 patients), followed by urinary tract infection (1.3 per 100 patients) and surgical-site infection (1.1 per 100 patients; 3.2 per 100 patients undergoing surgery). The median duration until the onset of infection was 19 days. Independent risk factors for NI were age between 1 and 12 months, a comorbidity score of 2 or greater, and a urinary catheter. Among surgical patients, an American Society of Anesthesiologists (ASA) score of 2 or greater was associated with any type of NI (P = .03). Enterobacteriaceae were the most frequent cause of NI, followed by coagulase-negative staphylococci; viruses were rarely the cause. CONCLUSIONS: This national prevalence survey yielded valuable information about the rate and risk factors of pediatric NI. A new comorbidity score showed promising performance. ASA score may be a predictor of NI. The season in which a prevalence survey is conducted must be considered, as this determines whether seasonal viral infections are observed. Periodic prevalence surveys are a simple and cost-effective method for assessing NI and comparing rates among pediatric hospitals.  相似文献   
25.
26.
27.
28.
Efavirenz is commonly used to treat patients coinfected with human immunodeficiency virus and tuberculosis. Previous clinical studies have observed paradoxically elevated efavirenz plasma concentrations in patients with the CYP2B6*6/*6 genotype (but not the CYP2B6*1/*1 genotype) during coadministration with the commonly used four-drug antituberculosis therapy. This study sought to elucidate the mechanism underlying this genotype-dependent drug-drug interaction. In vitro studies were conducted to determine whether one or more of the antituberculosis drugs (rifampin, isoniazid, pyrazinamide, or ethambutol) potently inhibit efavirenz 8-hydroxylation by CYP2B6 or efavirenz 7-hydroxylation by CYP2A6, the main mechanisms of efavirenz clearance. Time- and concentration-dependent kinetics of inhibition by the antituberculosis drugs were determined using genotyped human liver microsomes (HLMs) and recombinant CYP2A6, CYP2B6.1, and CYP2B6.6 enzymes. Although none of the antituberculosis drugs evaluated at up to 10 times clinical plasma concentrations were found to inhibit efavirenz 8-hydroxylation by HLMs, both rifampin (apparent inhibition constant [Ki] = 368 μM) and pyrazinamide (Ki = 637 μM) showed relatively weak inhibition of efavirenz 7-hydroxylation. Importantly, isoniazid demonstrated potent time-dependent inhibition of efavirenz 7-hydroxylation in both HLMs (inhibitor concentration required for half-maximal inactivation [KI] = 30 μM; maximal rate constant of inactivation [kinact] = 0.023 min−1) and recombinant CYP2A6 (KI = 15 μM; kinact = 0.024 min−1) and also formed a metabolite intermediate complex consistent with mechanism-based inhibition. Selective inhibition of the CYP2B6.6 allozyme could not be demonstrated for any of the antituberculosis drugs using either recombinant enzymes or CYP2B6*6 genotype HLMs. In conclusion, the results of this study identify isoniazid as the most likely perpetrator of this clinically important drug-drug interaction through mechanism-based inactivation of CYP2A6.  相似文献   
29.
Several studies point to various barriers in achieving sexual self-determination for people with disabilities as well as a high degree of thematic uncertainty among staff in residential homes. In addition, women with disabilities and people in institutions are especially at risk in a particular way, to be victims of sexual violence. The ReWiKs project develops, based on evaluated guidelines for sexual self-determination, materials in order to reflect the institutional handling of the subject. Training modules and recommendations are also developed. In addition, extracts of materials are created in simple language. All materials are evaluated before their publication in an intensive theory-practice dialogue.  相似文献   
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