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   1989篇
  免费   134篇
  国内免费   47篇
耳鼻咽喉   5篇
儿科学   99篇
妇产科学   34篇
基础医学   275篇
口腔科学   110篇
临床医学   259篇
内科学   512篇
皮肤病学   23篇
神经病学   98篇
特种医学   146篇
外科学   211篇
综合类   23篇
一般理论   1篇
预防医学   148篇
眼科学   15篇
药学   140篇
  1篇
中国医学   9篇
肿瘤学   61篇
  2023年   13篇
  2021年   40篇
  2020年   17篇
  2019年   22篇
  2018年   39篇
  2017年   35篇
  2016年   31篇
  2015年   42篇
  2014年   50篇
  2013年   73篇
  2012年   67篇
  2011年   65篇
  2010年   57篇
  2009年   52篇
  2008年   47篇
  2007年   102篇
  2006年   98篇
  2005年   86篇
  2004年   53篇
  2003年   51篇
  2002年   52篇
  2001年   52篇
  2000年   58篇
  1999年   56篇
  1998年   54篇
  1997年   75篇
  1996年   61篇
  1995年   57篇
  1994年   33篇
  1993年   39篇
  1992年   26篇
  1991年   34篇
  1990年   42篇
  1989年   42篇
  1988年   54篇
  1987年   35篇
  1986年   32篇
  1985年   38篇
  1984年   22篇
  1983年   22篇
  1982年   17篇
  1981年   13篇
  1980年   15篇
  1979年   13篇
  1978年   13篇
  1977年   19篇
  1975年   15篇
  1973年   18篇
  1972年   15篇
  1970年   14篇
排序方式: 共有2170条查询结果,搜索用时 15 毫秒
1.
2.
3.

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.  相似文献   
4.
In vascular smooth muscle, openers of ATP-dependent potassium channels (K ATP channels), such as P1075 (N-cyano-N’-(1,1-dimethylpropyl)-N’’-3-pyridylguanidine), produce relaxation. In this study we have investigated the effects of thiol-modifying agents on the binding of P1075 and on the 86Rb+ efflux stimulating and vasorelaxant effects of the opener in rat aortic rings. The increase in 86Rb+ efflux induced by P1075 was taken as a qualitative measure of K+ channel opening. The hydrophilic SH-group-oxidizing substance, thimerosal (1 to 100μM), abolished specific binding of [3H]-P1075 with an IC50 value of 7.6±1.2μM; at 30μM, the half time for inhibition was 38min. Two other thiol-oxidizing agents, PMB (4-hydroxy-mercuribenzoic acid) and DTBNP (2,2’-dithio-bis(5-nitropyridine)), inhibited binding up to 86% and 44%, respectively. The disulphide bond reducing substance, DTT (1,4-dithiothreitol, 0.1 to 1mM), reduced [3H]-P1075 binding by up to 20% and partially reversed the inhibitory effect of thimerosal. In 86Rb+ efflux experiments, thimerosal (3 to 100μM) concentration-dependently increased basal efflux but inhibited P1075-stimulated tracer efflux with an IC50 value of 7±1μM. The inhibitory effect occurred with a half-time of approximately 8min and was essentially reversed by DTT. In rings precontracted with noradrenaline, thimerosal inhibited the vasorelaxant effect in a noncompetitive manner, shifting the concentration-relaxation curves to the right and reducing maximum relaxation.The data show that oxidation of thiol groups interferes with the binding of the K ATP channel opener, P1075; concomitantly, the 86Rb+ efflux stimulating and the vasorelaxant effects are inhibited. Reduction of disulphide bonds by DTT has only minor effects on the action of P1075. Collectively, the results suggest that intact thiol groups are essential for the functioning of the KATP channel in rat aorta. The different kinetics governing the inhibition of opener binding and of opener-stimulated 86Rb+ efflux suggest that the SH-groups involved in the two processes differ in their accessibility to thimerosal and/or in their reactivity. Received: 7 April / Accepted: 9 July 1997  相似文献   
5.
6.
7.
On the basis of two case discussions the authors deal with the clinical significance of the gastric diverticula. In one case a traction diverticulum near to the cardia was found with simultaneously existing intramural leiomyoma of the wall of the stomach. In a second case a typical congenital diverticulum near to the cardia was concerned. It is referred to diagnostic possibilities, differential diagnostic questions and therapy.  相似文献   
8.
Pretransplant herpesvirus serology and acute graft-versus-host disease   总被引:3,自引:0,他引:3  
Logistic regression was used to analyze the influence of pretransplant herpesvirus antibodies, in both patients and donors, on the development of acute graft-versus-host disease in 111 consecutive HLA-identical bone marrow recipients. In bivariate analysis, recipient seropositivity for cytomegalovirus (P = 0.01), donor seropositivity for herpes simplex virus (P = 0.02), and low bone marrow cell dosage (P less than 0.05) were associated with a high incidence of grade II-IV acute GVHD. In multivariate analysis the P values were P less than 0.05 for a positive recipient CMV serology and P = 0.07 for a positive donor HSV serology. Positive serology for 1-2 herpes-viruses among recipients or donors both resulted in a 12% incidence of grade II-IV acute GVHD. Positive serology for 3-4 herpesviruses among patients or donors resulted in an incidence of 32% and 38% of acute GVHD, respectively (P less than 0.05). It is concluded that recipient and donor pretransplant herpesvirus immunity can be used to calculate the risk of moderate-to-severe acute GVHD.  相似文献   
9.
Four noninvasive rewarming techniques for mildly hypothermic subjects were compared. Seven subjects were cooled in a water bath of 15 degrees C for 2 h to an average esophageal temperature (Tes) of 36 degrees C. Thereafter, the subjects were rewarmed by immersion of the body in a water bath of 42 degrees C (Method 1), the body but not the extremities in water of 42 degrees C (Method 2), only the extremities in water of 42 degrees C (Method 3), or spontaneous rewarming in blankets (Method 4). Method 1 showed the highest rewarming rate in Tes (10.1 degrees C/h) and an afterdrop in Tes of 0.18 degrees C. Method 2 showed the same afterdrop, but a lower rewarming rate (7.5 degrees C/h). In Method 3, the heat uptake of the extremities was too low to rewarm the subjects effectively. The afterdrop and rewarming rate were 0.38 degrees C and 0.8 degrees C/h, respectively. Method 4 had the lowest rewarming rate (0.2 degrees C/h), and an afterdrop (0.14 degrees C) which was not significantly lower than that of Method 1 or 2. Therefore, Method 1 is recommended for rewarming mild hypothermic subjects because of its high rewarming rate and small afterdrop.  相似文献   
10.
In order to establish an univariate nonparametric pediatric tolerance region platelet function has been investigated in 105 healthy children and adolescents. In comparison to adult normal values, the bleeding time is shortened, spontaneous platelet aggregation is enhanced as well as collagen-induced platelet aggregation. 30% of the children showed an increased disaggregation in ADP-induced aggregation. A slight delay was found in the spreading of thrombocytes. Platelet volume shifted to the left. Values of beta-thromboglobulin were raised. Compared to adult values no alterations could be found in platelet shape-change. Changes of platelet functions were more apparent in the younger children.  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