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   1218篇
  免费   76篇
  国内免费   97篇
耳鼻咽喉   3篇
儿科学   43篇
妇产科学   14篇
基础医学   138篇
口腔科学   26篇
临床医学   161篇
内科学   255篇
皮肤病学   10篇
神经病学   184篇
特种医学   119篇
外科学   51篇
综合类   48篇
预防医学   116篇
眼科学   6篇
药学   178篇
肿瘤学   39篇
  2023年   9篇
  2022年   5篇
  2021年   22篇
  2020年   15篇
  2019年   16篇
  2018年   14篇
  2017年   12篇
  2016年   16篇
  2015年   30篇
  2014年   28篇
  2013年   43篇
  2012年   34篇
  2011年   29篇
  2010年   42篇
  2009年   40篇
  2008年   42篇
  2007年   86篇
  2006年   47篇
  2005年   49篇
  2004年   34篇
  2003年   54篇
  2002年   37篇
  2001年   41篇
  2000年   44篇
  1999年   28篇
  1998年   45篇
  1997年   43篇
  1996年   36篇
  1995年   33篇
  1994年   33篇
  1993年   40篇
  1992年   24篇
  1991年   30篇
  1990年   24篇
  1989年   49篇
  1988年   39篇
  1987年   25篇
  1986年   31篇
  1985年   17篇
  1984年   14篇
  1983年   8篇
  1982年   10篇
  1981年   6篇
  1980年   12篇
  1979年   6篇
  1978年   6篇
  1977年   10篇
  1973年   4篇
  1970年   3篇
  1961年   3篇
排序方式: 共有1391条查询结果,搜索用时 0 毫秒
991.
Impulsive aggressive behavior is common in psychiatric disorders and accounts for significant morbidity and mortality. However, little systematic treatment data exist from placebo-controlled trials for this symptom domain. This was a multicenter, randomized, double-blind, placebo-controlled study in which outpatients with a score of > or =15 on the Aggression scale of the Overt Aggression Scale-Modified (OAS-M) and who fulfilled DSM-IV criteria for Cluster B personality disorder (n=96), intermittent explosive disorder (n=116), or post-traumatic stress disorder (n=34) were randomized to divalproex sodium or placebo for 12 weeks duration. Based on average OAS-M Aggression scores over the last 4 weeks of treatment, a treatment effect was not observed in the intent-to-treat data set (combined across the three psychiatric disorders), but was observed in both intent-to-treat and evaluable data sets for patients with Cluster B personality disorders. In the Cluster B evaluable data set, statistically significant treatment differences favoring divalproex were also observed for component items of the OAS-M Aggression score, including verbal assault and assault against objects, as well as OAS-M Irritability score, and Clinical Global Impression (CGI)-Severity at multiple time points throughout the study. No treatment group difference was noted for overall premature discontinuation rate; however, across psychiatric diagnoses, 21 (17%) patients in the divalproex group prematurely discontinued because of an adverse event, as compared to 4 (3%) patients in the placebo group (p <0.001). While a treatment effect was not observed when all diagnostic groups were combined, in a large subgroup of patients with Cluster B disorders, divalproex was superior to placebo in the treatment of impulsive aggression, irritability, and global severity.  相似文献   
992.
993.
Severe esophageal strictures: indications for balloon catheter dilatation   总被引:1,自引:0,他引:1  
Bougienage of esophageal strictures is a traditional method of therapy for patients who present with a stricture sufficiently large to permit passage of a mercury-weighted rubber bougie. However, when the residual lumen is smaller than 12 mm diameter, bougie dilatation acquires a prohibitively high risk of esophageal perforation. Twenty patients who had severe esophageal strictures have undergone surgical repair or Eder-Puestow dilatation assisted by guidewire. Fluoroscopic balloon catheter dilatation obviated surgery and allowed subsequent standard bougienage both in hospital and at home performed by the patient. We discuss indications, technique, results, and complications.  相似文献   
994.
995.
996.
本文根据水动力学平衡药物控释系统的设计原理制备了美托洛尔胃内滞留漂浮型控释片剂(简称M-HBS)。实验表明,本品的体外溶出符合一级动力学过程(K′r=0.1651 h-1);贮存期为两年;人体胃内γ-闪烁照相结果表明,本品在胃内滞留时间(5~6 h)明显比普通片剂(1.0~1.5 h)长;体内动力学过程符合表观一级吸收与一级消除的单室模型;ⅳ美托洛尔体内为双室模型;体内数据经NONLIN计算机程序处理,求得各项参数:Ka=0.1944 h-1,K=0.1867 h-1,Vd=2.813,tmax=5.247 h,Cmax=125.1 ng/ml。本品的体内外数据具有显著的相关性(P<0.01)。  相似文献   
997.
A kinetic model of coupled droplet growth, gas uptake, and chemical reaction has been used to examine the possible changes to sulfuric acid aerosols as a result of exposure to respiratory ammonia under the conditions in the human airways. Results for a wide range of initial droplet sizes and concentrations spanning the extremes of likely atmospheric conditions are presented. It is predicted that gas phase reactions of SO2 will not significantly affect the neutralizing capability of airways ammonia. The effects of physical and chemical parameters on aerosol neutralization and growth are discussed and in particular, predictions of neutralization in typical inhalation times for aerosols characteristic of severe persistent London fogs and modern urban conditions are compared. The analysis supports the suggestion that the London fog episodes were unique in the relationship of the acid droplets formed to the neutralizing capability of ammonia in the human airways and that simple extrapolation of mortality and morbidity data from such episodes to modern conditions is unlikely to be valid.  相似文献   
998.
999.
Neuroleptic malignant syndrome, a dangerous but little-known complication of antipsychotic drugs, is often assumed to be rare. To assess the frequency of the syndrome in a large psychiatric hospital, the authors first reviewed the literature and developed operational diagnostic criteria. Using these criteria to survey nearly 500 neuroleptic-treated patients admitted during a 1-year period, they found that seven (1.4%) had experienced definite or probable neuroleptic malignant syndrome. In several cases, including one fatal case, the diagnosis of neuroleptic malignant syndrome was not immediately considered. The authors conclude that neuroleptic malignant syndrome may be more common than previously thought and may be underdiagnosed.  相似文献   
1000.
This study tested a behavior-suppressing punishment system and how its activity may be altered by agents known to interrupt or enhance serotonergic (5-HT) transmission. Holtzman male albino rats were tested for shuttle box avoidance acquisition and intertrial responding either 1 or 8 h following daily injections of fenfluramine (FEN) or fluoxetine (FXT). When the drug-test interval was 1 h, a time when both drugs are presumably potentiating 5-HT activity, avoidance acquisition and intertrial responding were impaired. When testing occurred 8 h after drug treatment, a time when 5-HT levels are unaltered by FXT and are maximally reduced by FEN, these drugs had no effect on avoidance acquisition, but FEN produced an increase in intertrial responses whereas FXT did not. These results support the proposal of an inhibitory 5-HT system. Furthermore, these data demonstrate that FEN is capable of exerting a biphasic action on intertrial responding and suggest that the time interval between drug administration and behavioural testing is a crucial variable when investigating FEN.  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