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   948篇
  免费   73篇
  国内免费   10篇
耳鼻咽喉   3篇
儿科学   11篇
妇产科学   16篇
基础医学   140篇
口腔科学   19篇
临床医学   83篇
内科学   222篇
皮肤病学   28篇
神经病学   51篇
特种医学   18篇
外科学   139篇
综合类   29篇
一般理论   3篇
预防医学   87篇
眼科学   32篇
药学   74篇
中国医学   12篇
肿瘤学   64篇
  2024年   2篇
  2023年   16篇
  2022年   31篇
  2021年   45篇
  2020年   34篇
  2019年   21篇
  2018年   37篇
  2017年   28篇
  2016年   29篇
  2015年   25篇
  2014年   34篇
  2013年   48篇
  2012年   84篇
  2011年   69篇
  2010年   45篇
  2009年   38篇
  2008年   51篇
  2007年   46篇
  2006年   49篇
  2005年   41篇
  2004年   39篇
  2003年   38篇
  2002年   40篇
  2001年   22篇
  2000年   11篇
  1999年   23篇
  1998年   1篇
  1997年   9篇
  1996年   8篇
  1995年   3篇
  1994年   6篇
  1993年   7篇
  1992年   8篇
  1991年   8篇
  1990年   6篇
  1989年   9篇
  1988年   3篇
  1987年   2篇
  1986年   5篇
  1985年   1篇
  1983年   3篇
  1978年   1篇
  1973年   2篇
  1972年   2篇
  1968年   1篇
排序方式: 共有1031条查询结果,搜索用时 15 毫秒
61.
To test the hypothesis that hip fracture is associated with physical activity in Thai elderly men, a case-control study was conducted in Bangkok, Thailand. A total of 187 men aged 51 years over, resident in Bangkok, admitted consecutively with a radiologically confirmed first hip fracture were studied. 177 age-matched community controls were randomly recruited from the same neighborhood of the cases. Physical activity was independently associated with reduced risk of hip fracture after controlling for confounding factors. Very active and active past physical activity markedly reduced risk of hip fracture in comparison to subjects with inactive past physical activity. Recent active physical activity was also protective against hip fracture. This prompts a need to identify strategy to promote physical activity among the elderly and at an early age.  相似文献   
62.
63.
槟榔灭钉螺增效成分的研究   总被引:2,自引:0,他引:2  
冯青  李桂玲 《中药材》1999,22(11):572-574
对从槟榔(Areca catechu L.的干燥成熟种子)核中分离出的组分进行灭钉螺增效实验,研究表明,最有效成分为槟榔碱(Arecoline,Are.)。它与植物灭钉螺药商陆皂甙或化学灭钉螺药五氨酸钠等联合使用,可显著降低二者的投药量。  相似文献   
64.
Dengue virus (DENV) and Zika virus (ZIKV) belong to the Flaviviridae family of viruses spread by Aedes aegypti mosquitoes in tropical and subtropical areas. Accurate diagnostic tests to differentiate the 2 infections are necessary for patient management and disease control. Using characterized ZIKV and DENV patient plasma in a blind manner, we validated an ELISA and a rapid immunochromatographic test for ZIKV detection. We engineered the ZIKV nonstructural protein 1 (NS1) for sensitive serologic detection with low cross reactivity against dengue and developed monoclonal antibodies specific for the ZIKV NS1 antigen. As expected, the serologic assays performed better with convalescent than acute plasma samples; the sensitivity ranged from 71% to 88%, depending on the performance of individual tests (IgM/IgG/NS1). Although serologic tests were generally less sensitive with acute samples, our ZIKV NS1 antibodies were able to complement the serologic tests to achieve greater sensitivity for detecting early infections.  相似文献   
65.
Cancer Chemotherapy and Pharmacology - CC-486 is an oral formulation of azacitidine that allows for extended dosing schedules to prolong azacitidine exposure to malignant cells and maximize...  相似文献   
66.
We assessed the long-term protection afforded by a killed whole-cell oral cholera vaccine produced in Vietnam. A mass immunization of children and adults with the killed whole-cell oral cholera vaccine was undertaken in half of the communes of Hue, Vietnam, in 1998; the remaining communes were immunized in 2000. No cholera was observed in Hue until 2003, when an outbreak of El Tor cholera made it possible to conduct a case-control study. The overall vaccine effectiveness 3-5 years after vaccination was 50% (9-63%). This low-cost, easily administered vaccine should be considered as a tool for the control of cholera.  相似文献   
67.
68.
OBJECTIVE: To compare the incidence of carbapenemase genes in Acinetobacter baumannii between two time periods. METHODS: We studied 114 isolates of imipenem-resistant A. baumannii collected over two 5 month periods (in 1996 and 2001). Isolates showing carbapenemase activity by plate bioassay were screened for carbapenemase genes using PCR. Chromosomal DNA from strains carrying carbapenemase genes was subjected to PFGE after digestion with ApaI. RESULTS: The incidence of imipenem-resistant A. baumannii in our hospital rose from 1.1 per 1000 admissions in 1996 to 2.3 per 1000 admissions in 2001. However, the number of carbapenemase-producing A. baumannii rose only slightly in 2001 (0.8 per 1000 admissions) compared to 1996 (0.5 per 1000 admissions). Of 44 isolates with carbapenemase activity, 4 isolates carried bla(IMP-4), 5 carried bla(OXA-58), and 40 carried bla(OXA-23). In addition, most isolates carried a bla(OXA-51)-type beta-lactamase gene. All strains with bla(IMP-4), also carried bla(OXA-58) and bla(PSE-1), but not bla(OXA-51)-type beta-lactamase genes. PCR analysis repeated on seven recent isolates of susceptible A. baumannii showed only the presence of bla(OXA-51)-type beta-lactamase genes. A total of five novel bla(OXA-51)-type beta-lactamase genes (bla(OXA-88),-91,-93,-94, and -95) and one new bla(OXA-58)-type beta-lactamase gene (bla(OXA-96)) were found. CONCLUSIONS: The incidence of carbapenemase genes did not vary significantly between the two study periods. There is a wide diversity of OXA genes in A. baumannii in Singapore. The most common carbapenemase gene found in our study was bla(OXA-23).  相似文献   
69.

AIM

Aflibercept (VEGF-Trap), a novel anti-angiogenic agent that binds to VEGF, has been investigated for the treatment of cancer. The aim of this study was to develop a mechanism-based pharmacokinetic (PK) model for aflibercept to characterize its binding to VEGF and its PK properties in healthy subjects.

METHODS

Data from two phase I clinical studies with aflibercept administered as a single intravenous infusion were included in the analysis. Free and bound aflibercept concentration−time data were analysed using a nonlinear mixed-effects modelling approach with MONOLIX 3.1.

RESULTS

The best structural model involved two compartments for free aflibercept and one for bound aflibercept, with a Michaelis–Menten type binding of free aflibercept to VEGF from the peripheral compartment. The typical estimated clearances for free and bound aflibercept were 0.88 l day−1 and 0.14 l day−1, respectively. The central volume of distribution of free aflibercept was 4.94 l. The maximum binding capacity was 0.99 mg day−1 and the concentration of aflibercept corresponding to half of maximum binding capacity was 2.91 µg ml−1. Interindividual variability of model parameters was moderate, ranging from 13.6% (Vmax) to 49.8% (Q).

CONCLUSION

The present PK model for aflibercept adequately characterizes the underlying mechanism of disposition of aflibercept and its nonlinear binding to VEGF.  相似文献   
70.
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