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   2231篇
  免费   122篇
  国内免费   8篇
耳鼻咽喉   14篇
儿科学   33篇
妇产科学   35篇
基础医学   500篇
口腔科学   28篇
临床医学   207篇
内科学   469篇
皮肤病学   39篇
神经病学   158篇
特种医学   53篇
外科学   296篇
综合类   8篇
预防医学   157篇
眼科学   23篇
药学   181篇
中国医学   1篇
肿瘤学   159篇
  2023年   26篇
  2022年   73篇
  2021年   104篇
  2020年   38篇
  2019年   55篇
  2018年   50篇
  2017年   41篇
  2016年   55篇
  2015年   70篇
  2014年   80篇
  2013年   100篇
  2012年   148篇
  2011年   140篇
  2010年   96篇
  2009年   84篇
  2008年   115篇
  2007年   134篇
  2006年   136篇
  2005年   120篇
  2004年   107篇
  2003年   76篇
  2002年   75篇
  2001年   20篇
  2000年   22篇
  1999年   18篇
  1998年   17篇
  1997年   28篇
  1996年   16篇
  1995年   10篇
  1994年   14篇
  1993年   7篇
  1992年   17篇
  1991年   13篇
  1990年   17篇
  1989年   22篇
  1988年   24篇
  1987年   17篇
  1986年   15篇
  1985年   20篇
  1984年   13篇
  1983年   10篇
  1982年   8篇
  1976年   6篇
  1975年   9篇
  1974年   8篇
  1973年   7篇
  1972年   9篇
  1971年   7篇
  1970年   9篇
  1969年   12篇
排序方式: 共有2361条查询结果,搜索用时 46 毫秒
1.
2.
3.
Septic or inflammatory stimuli suppress drug metabolism by cytochrome P-450 in the liver, presumably at the pretranslational level. We have shown previously that nitric oxide is responsible at least in part for the inhibition by bacterial lipopolysaccharide of phenobarbital-induced CYP2B1/2 activity in vivo. This was attributed to the interaction of nitric oxide with heme in the active-center of cytochrome P450, leading to enzyme inactivation. Here, we report of nitric oxide with heme in the active-center of cytochrome P450, leading to enzyme inactivation. Here, we report that endogeneous nitric oxide also contributes to LPS-induced suppression of CYP2B1/2 in vivo by down-regulating the expression of CYP2B1/2 protein and mRNA.  相似文献   
4.
5.
According to contemporary views, the glutamatergic system is implicated in the pathogenesis of schizophrenia, and atypical neuroleptics exert their effects (at least partially) through the glutamatergic system. Immunoreactive glutamate-metabolising enzymes, such as glutamine synthetase-like protein (GSLP) and two glutamate dehydrogenase isoenzymes (GDH), have been discovered in human platelets. The amount of GSLP in the platelets of 40 chronic patients with schizophrenia was found to be significantly higher than in 33 controls (consistent with our previous finding of increased amounts of GSLP in the prefrontal cortex of chronic schizophrenia patients). Moreover, survival analysis of the group of patients treated with olanzapine for 28 weeks showed that the larger amount of GSLP measured in platelets before treatment, the shorter the treatment time needed to achieve a positive clinical response (defined a priori as > or = 20% reduction in PANSS total score from the initial level before the treatment). Hence, GSLP level may serve as a predictor of the treatment duration to achieve a positive outcome with olanzapine. Both GSLP and GDH were found significantly changed in the course of treatment; hence, treatment with olanzapine influences the amounts of glutamate-metabolising enzymes in the platelets of chronic schizophrenia patients.  相似文献   
6.
7.

Background:   

Cases of extrahepatic biliary tree trauma are not as common as other intraabdominal injuries and may pose a diagnostic and therapeutic challenge.  相似文献   
8.
A patient developed a huge diaphragmatic hernia following laparoscopic gastric banding. Almost the entire stomach was incarcerated within the left chest. Segmental necrosis of the greater curvature of the stomach necessitated partial gastrectomy. The postoperative course was uneventful. The etiology, diagnosis and treatment of this previously undescribed complication of laparoscopic gastric banding are addressed in relation to the present case.  相似文献   
9.
Design, spectrum measurements and simulations for an alpha-particle irradiator for bystander effect and genomic instability experiments are presented. Measured alpha-particle energy spectra were used to confirm the characteristics of the source of the irradiator specified by the manufacturer of the source. The spectra were measured in vacuum with a high-resolution spectrometer and simulated with an AASI Monte Carlo code. As a next step, we simulated alpha-particle energy spectra at the target plane of the irradiator for three different source-to-target distances. In these simulations, helium was used as the medium between the source and the exit window of the irradiator; its pressure and temperature corresponded to those of the ambient air. Mean energies and full-widths at half-maximum (FWHM) were calculated for the three different helium gas tracks.  相似文献   
10.
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