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   49409篇
  免费   4606篇
  国内免费   3721篇
耳鼻咽喉   330篇
儿科学   440篇
妇产科学   502篇
基础医学   5752篇
口腔科学   766篇
临床医学   7042篇
内科学   7625篇
皮肤病学   602篇
神经病学   2683篇
特种医学   2037篇
外国民族医学   24篇
外科学   4592篇
综合类   8031篇
现状与发展   15篇
一般理论   7篇
预防医学   3066篇
眼科学   1525篇
药学   5202篇
  88篇
中国医学   3000篇
肿瘤学   4407篇
  2024年   154篇
  2023年   895篇
  2022年   2118篇
  2021年   2721篇
  2020年   2037篇
  2019年   1694篇
  2018年   1826篇
  2017年   1583篇
  2016年   1513篇
  2015年   2268篇
  2014年   2755篇
  2013年   2393篇
  2012年   3565篇
  2011年   4020篇
  2010年   2437篇
  2009年   1919篇
  2008年   2544篇
  2007年   2616篇
  2006年   2536篇
  2005年   2613篇
  2004年   1538篇
  2003年   1390篇
  2002年   1176篇
  2001年   1144篇
  2000年   1209篇
  1999年   1261篇
  1998年   813篇
  1997年   826篇
  1996年   636篇
  1995年   582篇
  1994年   540篇
  1993年   312篇
  1992年   393篇
  1991年   316篇
  1990年   294篇
  1989年   245篇
  1988年   232篇
  1987年   210篇
  1986年   155篇
  1985年   112篇
  1984年   50篇
  1983年   38篇
  1982年   19篇
  1981年   12篇
  1980年   13篇
  1979年   12篇
  1966年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
This study investigated the hypocholesterolaemic effects of bitter melon aqueous extracts (BMAE) in vitro, the inhibitory effects of BMAE on pancreatic cholesterol esterase (CEase) and incorporation of cholesterol into micelles were investigated. BMAE decreased the in vitro micellar solubility of cholesterol in a dose-dependent manner. The conformation of CEase was investigated by means of circular dichroism (CD) and fluorescence. The result revealed the decrease of α-helix contents, increase of β-sheet and exposure of aromatic amino acid residuals. The incorporation of cholesterol into micelles was inhibited by BMAE. A complex was observed by transmission electron microscopy (TEM), which indicated interaction between cholesterol and BMAE. The result revealed that BMAE can play a role in decreased intestinal cholesterol absorption via inhibition of CEase, and of micelle formation.  相似文献   
2.
3.
4.
5.
6.
This meta-analysis examined whether early decompressive craniectomy (DC) can improve control of intracranial pressure (ICP) and mortality in patients with traumatic brain injury (TBI).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until May 14, 2015, using the following terms: traumatic brain injury, refractory intracranial hypertension, high intracranial pressure, craniectomy, standard care, and medical management. Randomized controlled trials in which patients with TBI received DC and non-DC medical treatments were included.Of the 84 articles identified, 8 studies were selected for review, with 3 randomized controlled trials s having a total of 256 patients (123 DCs, 133 non-DCs) included in the meta-analysis. Patients receiving DC had a significantly greater reduction of ICP and shorter hospital stay. They also seemed to have lower odds of death than patients receiving only medical management, but the P value did not reach significance (pooled odds ratio 0.531, 95% confidence interval 0.209–1.350, Z = 1.95, P = 0.183) with respect to the effect on overall mortality; a separate analysis of 3 retrospective studies yielded a similar result.Whereas DC might effectively reduce ICP and shorten hospital stay in patients with TBI, its effect in decreasing mortality has not reached statistical significance.  相似文献   
7.
从质量守恒定律出发,以Buswell提出的垃圾好氧降解反应方程式为基础,建立了计算通风量的化学计量模型;以达西定律为基础,建立了计算通风压力的数学模型;并将其应用于某封场垃圾填埋场原位好氧治理工程的计算,验证了2个模型的合理性和准确性,可为生活垃圾填埋场好氧生物反应器工艺设计和设备选型提供理论数据参考。  相似文献   
8.
BACKGROUND: The validity of parent reports regarding children's attention-deficit/hyperactivity disorder (ADHD) symptoms has been questioned. This study assessed whether parent reports were as sensitive as teacher reports to document change in ADHD symptoms during clinical trials with atomoxetine. METHODS: Data were compared from two randomized, double-blind, placebo-controlled clinical trials of atomoxetine using different versions (parent or teacher) of the same rating scale (Attention-Deficit/Hyperactivity Disorder Rating Scale-IV [parent or teacher] Version: Investigator Administered and Scored - ADHD RS). Exclusion criteria included history of bipolar disorder, psychosis, seizures, alcohol abuse, or positive drug screen. Patients (6-16 years old) were treated with atomoxetine (titrated to a maximum dose of 1.8 mg/kg/day) administered once daily for up to 7 weeks. Parent and teacher ratings were compared using an analysis of covariance (ANCOVA) model. RESULTS: The analysis (n = 318) showed that treatment effects (mean change, baseline to endpoint) were similar between parent and teacher ratings (total, p = .762; inattention, p = .519; hyperactive/impulsive, p = .955). Effect sizes also were similar based on total scores (parent ratings = .69; teacher ratings = .63). CONCLUSIONS: Parent reports are as sensitive as teacher reports in assessing the efficacy of long-acting pharmacologic treatment for ADHD in children during clinical trials using the nonstimulant atomoxetine.  相似文献   
9.
医学插图的艺术创作   总被引:1,自引:1,他引:0  
介绍了医学插图艺术创作的方法:即在依据医学科学内容的基础上,遵循美学规律,运用科学的艺术表现形式,准确、形象、生动地表达出医学科学的深刻内涵,从而实现医学科学与艺术完美结合的创作目标。  相似文献   
10.
本文报告了暗纹节菱孢[Arthinium phaeospemum(Corda)Ellis]所致皮肤真菌病的组织病理学及超微结构观察。HE、PAS、镀银染色(Szatri)法及铅铀染色,对皮损的组织病理改变,进行了光镜及透射电镜观察。光镜下发现暗纹节菱孢引起真皮及皮下脂肪组织广泛性病理浸润,由多种细胞构成的肉芽肿,尤其对皮肤附属器严重破坏。在病理浸润中可见球形、卵圆形、菱形及晶体形,玫瑰红色、棕色及褐色孢子。透射电镜下见真皮成纤维细胞胞浆内吞噬多数界线清楚的圆形小体,空泡内也有相同的小体,胞浆空泡甚多,胞核完整。同时见到破坏的溶酶体。病理浸润内形态各异的孢子及不同颜色,是孢子生长的不同阶段。  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