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   3567篇
  免费   205篇
  国内免费   7篇
耳鼻咽喉   13篇
儿科学   112篇
妇产科学   96篇
基础医学   369篇
口腔科学   68篇
临床医学   390篇
内科学   843篇
皮肤病学   47篇
神经病学   330篇
特种医学   252篇
外国民族医学   1篇
外科学   446篇
综合类   48篇
一般理论   3篇
预防医学   297篇
眼科学   47篇
药学   152篇
中国医学   3篇
肿瘤学   262篇
  2023年   34篇
  2022年   35篇
  2021年   99篇
  2020年   45篇
  2019年   83篇
  2018年   97篇
  2017年   75篇
  2016年   79篇
  2015年   82篇
  2014年   112篇
  2013年   177篇
  2012年   199篇
  2011年   220篇
  2010年   123篇
  2009年   114篇
  2008年   188篇
  2007年   202篇
  2006年   183篇
  2005年   172篇
  2004年   173篇
  2003年   180篇
  2002年   136篇
  2001年   77篇
  2000年   90篇
  1999年   74篇
  1998年   42篇
  1997年   29篇
  1996年   27篇
  1995年   19篇
  1994年   18篇
  1993年   20篇
  1992年   36篇
  1991年   39篇
  1990年   33篇
  1989年   32篇
  1988年   18篇
  1987年   28篇
  1986年   18篇
  1985年   22篇
  1984年   17篇
  1983年   15篇
  1982年   11篇
  1980年   12篇
  1979年   11篇
  1978年   10篇
  1975年   11篇
  1974年   12篇
  1973年   19篇
  1920年   9篇
  1919年   16篇
排序方式: 共有3779条查询结果,搜索用时 15 毫秒
21.
22.
The use of recombinant severe acute respiratory syndrome-coronavirus (SARS-CoV) nucleocapsid protein (N) enzyme-linked immunosorbent assay (ELISA)-based antibody and antigen tests for diagnosis of SARS-CoV infections have been widely reported. However, no recombinant SARS-CoV spike protein (S)-based ELISA is currently available. In this article, we describe the problems and solutions of setting up the recombinant SARS-CoV S-based ELISA for antibody detection. The SARS-CoV S-based immunoglobulin M (IgM) and IgG ELISAs were evaluated and compared with the corresponding N-based ELISA for serodiagnosis of SARS-CoV pneumonia, using sera from 148 healthy blood donors who donated blood 3 years ago as controls and 95 SARS-CoV pneumonia patients in Hong Kong. Results obtained by the recombinant S (rS)-based IgG ELISA using the regenerated S prepared by dialysis with decreasing concentrations of urea or direct addition of different coating buffers, followed by addition of different regeneration buffer, identified 4 M urea and 1 M sarcosine for plate coating and no regeneration buffer as the most optimal conditions for antibody detection. The specificities of the S-based ELISA for IgG and IgM detection were 98.6% and 93.9%, with corresponding sensitivities of 58.9% and 74.7%, respectively. The sensitivity of the rN IgG ELISA (94.7%) is significantly higher than that of the rS IgG ELISA (P < 0.001), whereas the sensitivity of the rS IgM ELISA is significantly higher than that of the rN IgM ELISA (55.2%) (P < 0.01). An ELISA for detection of IgM against S and N could be more sensitive than one that detects IgM against N alone for serodiagnosis of SARS-CoV pneumonia.  相似文献   
23.
24.
25.
26.
Quality of Life Research - (1) To develop a personalized health outcome profile as a feedback tool to improve self-management in people living with chronic conditions such as HIV and (2) to...  相似文献   
27.
Our previous results indicated that the trihydroxamate ligand, trisuccin, was a promising bifunctional chelating agent (BCA) for radiometal labeling of monoclonal antibodies with rhenium and technetium. An interest was developed to evaluate structural modifications of this compound from both synthetic and biological points of view. In this report we describe the synthesis of an esterified trisuccin (referred to as trisester), and conjugation of this new derivative to MAb CC49, radiolabeling of this conjugate with rhenium-188 (188Re), and biodistribution of the labeled conjugate in athymic nude mice. Thus, trisuccin (1) was esterified with benzyl 4-hydroxybenzoate in a DCC/DMAP reaction followed by removal of all benzyl protecting groups with catalytic hydrogenation. The resulting product was conjugated to CC49 by the active ester technique, through formation of the 2-nitrophenyl ester 6, and the conjugate was radiolabeled with generator-produced 188Re. The lead molecule trisuccin 1 was also conjugated to CC49 through the active ester 5 and the conjugate was radiolabeled by the same procedure to serve as the control conjugate. Biodistributions of the labeled conjugates were studied in athymic nude mice, transplanted s.c. with LS174T human colon cancer xenografts. Although an increase in the radiolabeling yield was observed for the esterified ligand-CC49 conjugate, as well as some increase in its immunoreactivity, as compared to those for the parent trisuccin molecule, there were no significant differences in their biodistribution. This new compound therefore may be useful in improving the conjugation and radiolabeling chemistries of this trihydroxamate ligand system.  相似文献   
28.
29.
This study describes the construction and preliminary validation of the Israeli Sexual Behavior Inventory (ISBI). The ISBI was primarily designed to assess the impact of sexual problems, chronic illness and disability on sexual functioning and experience. Scales were designed to measure three areas of healthy sexual functioning and three areas of sexual dysfunction for both males and females. To provide normative data to which clinical samples can be compared, a large randomly selected sample from an adult male and female population was used for scale construction and preliminary validation. Scale reliabilities, intercorrelations between the ISBI scales, comparisons between the above sample and a clinical sample provide evidence of the ISBI's reliability and validity.  相似文献   
30.
6-Hydroxydopamine (6-OHDA) is a neurotoxin used in the induction of experimental Parkinson's disease in both animals and cultured neuronal cells. Biochemical and molecular approaches showed previously that low doses of 6-OHDA induced apoptosis in PC12 cells, while high doses of this neurotoxin induced necrosis. Melatonin has been shown to protect against the neuronal programmed cell death induced by 6-OHDA, although it was not able to prevent the massive necrotic cellular death occurring after the addition of high doses of the neurotoxin. In the present work, we demonstrate by ultrastructural analysis that although low doses of 6-OHDA induced apoptosis in PC12 cells, it also damaged the non-apoptotic cells, morphologically corresponding this damage to incipient and reversible necrotic lesions. When the doses of the neurotoxin increase, there are still apoptotic cells, although most of the cells show necrotic irreversible lesions. We also found that melatonin partially prevents the incipient necrotic lesions caused by low doses of 6-OHDA. The fact that melatonin was shown in previous work to prevent apoptosis caused by low doses of 6-OHDA, but not necrosis induced by high doses of the neurotoxin, seemed to indicate that this agent is only able to protect against apoptosis. However, our present results, melatonin preventing also the incipient necrotic neuronal lesions, suggest that this hormone may provide a general protection against cell death, suggesting that higher doses should be tried in order to prevent the necrotic cell death induced by high doses of the neurotoxin.  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