首页 | 官方网站   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   692篇
  免费   28篇
  国内免费   14篇
医药卫生   734篇
  2021年   1篇
  2020年   4篇
  2019年   3篇
  2018年   4篇
  2017年   3篇
  2016年   5篇
  2015年   7篇
  2014年   16篇
  2013年   15篇
  2012年   7篇
  2011年   12篇
  2010年   15篇
  2009年   18篇
  2008年   6篇
  2007年   22篇
  2006年   10篇
  2005年   13篇
  2004年   5篇
  2003年   11篇
  2002年   6篇
  2001年   9篇
  2000年   6篇
  1999年   27篇
  1998年   39篇
  1997年   47篇
  1996年   38篇
  1995年   39篇
  1994年   23篇
  1993年   26篇
  1992年   17篇
  1991年   20篇
  1990年   16篇
  1989年   14篇
  1988年   27篇
  1987年   26篇
  1986年   25篇
  1985年   18篇
  1984年   11篇
  1983年   8篇
  1982年   18篇
  1981年   12篇
  1980年   22篇
  1979年   4篇
  1978年   12篇
  1977年   22篇
  1976年   12篇
  1975年   8篇
  1974年   1篇
  1963年   2篇
  1943年   1篇
排序方式: 共有734条查询结果,搜索用时 265 毫秒
81.
Bile duct stones: percutaneous transhepatic removal   总被引:3,自引:0,他引:3  
Clouse  ME; Stokes  KR; Lee  RG; Falchuk  KR 《Radiology》1986,160(2):525-529
Percutaneous transhepatic intervention for transduodenal removal of biliary stones was performed 38 times in 34 patients with obstructive jaundice, biliary colic, and cholangitis. The technique entailed the percutaneous transhepatic placement of a modified Dormia basket in the common duct with the flexible tip in the duodenum. The stones were passed into the duodenum and were crushed, or were crushed in the common duct and passed as fragments into the duodenum. In addition to the snare procedure, monooctanoin was used 18 times to dissolve remaining fragments of stone and sludge that could not be snared and passed into the duodenum. The average time for completion of the procedure was 10 days. There were no deaths from the procedure. The complication rate was 21%--probably no greater than would occur with surgery in a similar patient population. The procedure can be performed when endoscopic retrograde cholangiopancreatography and sphincterotomy with stone removal is technically impossible or refused, and in patients who have previously undergone choledochojejunostomy.  相似文献   
82.
83.
应用乙酰胆碱选择性微电极技术,观察到小剂量赛拉嗪(2.0和6.0mg·kg-1)可显著增加大鼠海马CA1区ACh的含量,而大剂量赛拉嗪(10.0mg·kg-1)及咪唑克生(0.6mg·kg-1)则作用相反。咪唑克生虽可明显拮抗赛拉嗪的作用,但海马CA1区ACh的含量仍显著低于正常水平。在去兰斑核的大鼠上,赛拉嗪(2.0和6.0mg·kg-1)及咪唑克生(0.6mg·kg-1)分别对海马CA1区ACh的含量具有减少和增加作用,且咪唑克生拮抗赛拉嗪的作用后,海马CA1区ACh的含量基本恢复至正常水平。结果提示,赛拉嗪对麻醉大鼠海马CA1区ACh含量呈双相性影响,咪唑可生虽能显著拮抗赛拉嗪的作用,但海马CA1区ACh的含量仍明显低于正常水平,可能分别与赛拉嗪和咪唑克生降低或提高中枢NE能系统的功能有关。  相似文献   
84.
This article reviews the usefulness and importance of written information, specifically leaflets, being given to patients. Evidence suggesting how both patient and doctor may benefit from the giving of written information is reviewed. Identification of good practice relating to the content and readability of leaflets is discussed. An argument is put forward that the giving of written information is an under-utilized resource in contributing to improving patient outcomes but that this may be changing with the increasing use of patient leaflet databases. The advantages and disadvantages of computer- generated patient leaflets are discussed and desirable further areas of research on computer-generated leaflets are proposed.   相似文献   
85.
The role of basal forebrain-derived cholinergic afferents in the development of neocortex was studied in postnatal rats. Newborn rat pups received intraventricular injections of 192 IgG-saporin. Following survival periods ranging from 2 days to 6 months, the brains were processed to document the cholinergic lesion and to examine morphological consequences. Immunocytochemistry for choline acetyltransferase (ChAT) and in situ hybridization for ChAT mRNA demonstrate a loss of approximately 75% of the cholinergic neurons in the medial septum and nucleus of the diagonal band of Broca in the basal forebrain. In situ hybridization for glutamic acid decarboxylase mRNA reveals no loss of basal forebrain GABAergic neurons. Acetylcholinesterase histochemistry demonstrates a marked reduction of the cholinergic axons in neocortex. Cholinergic axons are reduced throughout the cortical layers; this reduction is more marked in medial than in lateral cortical areas. The thickness of neocortex is reduced by approximately 10%. Retrograde labeling of layer V cortico-collicular pyramidal cells reveals a reduction in cell body size and also a reduction in numbers of branches of apical dendrites. Spine densities on apical dendrites are reduced by approximately 20-25% in 192 IgG- saporin-treated cases; no change was detected in number of spines on basal dendrites. These results indicate a developmental or maintenance role for cholinergic afferents to cerebral cortical neurons.   相似文献   
86.
麻黄碱与伪麻黄碱是中药麻黄的主要有效成分,也是一对化学物理性质很相似的差向异构体。二者的结构只是构象不同,用色谱方法进行分离有一定的难度。目前已有在苯基和腈基键合固定相上进行HPLC分离的报道(1,2)。本文成功地引入共轭方向法在μBondapak C18色谱柱上对流动相组成进行了条件优化,优化后的色谱条件下麻黄碱与伪麻黄碱的分离情况令人满意。  相似文献   
87.
88.
Diabetic retinopathy remains a major cause of loss of vision. The Diabetes Control and Complications Trial (DCCT) has implicated hyperglycaemia as a probable major direct causative factor in the pathogenesis of diabetic retinopathy. There are several plausible mechanisms by which high glucose concentrations could lead to the functional and later structural changes characterising diabetic retinopathy. These include increased activity of the aldose reductase pathway, increase de novo synthesis of diacylglycerol from glucose, causing protein kinase C activation, increased non-enzymatic glycation and increased oxidative damage. The demonstration of the potential roles of these pathways and the subsequent effects of growth factors in enhancing angiogenesis provide potential new approaches to the prevention and treatment of diabetic retinopathy.  相似文献   
89.
Glenoid labrum: preliminary work with use of radial-sequence MR imaging   总被引:1,自引:0,他引:1  
Munk  PL; Holt  RG; Helms  CA; Genant  HK 《Radiology》1989,173(3):751-753
The authors describe a magnetic resonance imaging method for examination of the glenoid labrum of the shoulder joint that utilizes a radial fast-imaging sequence. Seven shoulders were examined: a total of five in three healthy asymptomatic volunteers, one in a symptomatic patient not suspected of having a lesion of the glenoid labrum, and one in a patient with recurrent shoulder dislocation and surgical proof of an extensive tear of the labrum. The preliminary results suggest that this technique may advantageously demonstrate pathologic changes in the glenoid labrum and may contribute to the evaluation of the unstable and painful shoulder.  相似文献   
90.
The authors tested the effectiveness of orally administered delta-9-tetrahydrocannabinol (THC) as compared to prochlorperazine for the alleviation of symptoms, such as vomiting and nausea, experienced by patients receiving radiotherapy. The test subjects rated the severity of their illness, as well as the extent of their subsequent moods, their level of concentration, their amount of physical activity, and their desire for social interaction. They chose the drug they preferred and recorded its side effects. The use of THC was slightly more beneficial than the use of prochlorperazine.  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-23

京公网安备 11010802026262号