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   20676篇
  免费   1166篇
  国内免费   175篇
耳鼻咽喉   366篇
儿科学   875篇
妇产科学   548篇
基础医学   2840篇
口腔科学   696篇
临床医学   2040篇
内科学   3785篇
皮肤病学   593篇
神经病学   1979篇
特种医学   1043篇
外国民族医学   4篇
外科学   2683篇
综合类   347篇
一般理论   17篇
预防医学   1548篇
眼科学   401篇
药学   1156篇
  5篇
中国医学   118篇
肿瘤学   973篇
  2023年   173篇
  2022年   254篇
  2021年   553篇
  2020年   396篇
  2019年   442篇
  2018年   622篇
  2017年   486篇
  2016年   565篇
  2015年   677篇
  2014年   813篇
  2013年   984篇
  2012年   1230篇
  2011年   1129篇
  2010年   756篇
  2009年   731篇
  2008年   918篇
  2007年   1043篇
  2006年   909篇
  2005年   928篇
  2004年   923篇
  2003年   838篇
  2002年   722篇
  2001年   470篇
  2000年   465篇
  1999年   441篇
  1998年   262篇
  1997年   234篇
  1996年   166篇
  1995年   145篇
  1994年   128篇
  1993年   134篇
  1992年   226篇
  1991年   203篇
  1990年   188篇
  1989年   168篇
  1988年   193篇
  1987年   157篇
  1986年   148篇
  1985年   142篇
  1984年   127篇
  1983年   101篇
  1982年   98篇
  1981年   86篇
  1980年   66篇
  1979年   108篇
  1978年   97篇
  1977年   66篇
  1975年   90篇
  1974年   83篇
  1973年   104篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
51.
We describe the case of a 79-year-old woman with mitral insufficiency and a double-orifice mitral valve (DOMV), discovered by echocardiography. Transthoracic echocardiography showed two insufficiency jets. Transesophageal echocardiography revealed a DOMV. Each orifice was provided with a subvalvular apparatus. No associated congenital abnormalities were present. Our case demonstrates that even in elderly patients with a double regurgitant jet, DOMV should be suspected and assessed by transesophageal echocardiography.  相似文献   
52.
53.
The results of 194 consecutive interlocking nailings for 95 fractures in the tibia and 99 fractures in the femur with a median observation time of 22 months are presented. Three fractures were not consolidated radiologically at follow-up; three deep infections were recorded, all of which healed. Shortening > 1cm was recorded in 17 fractures, rotatory malalignment > 5 ° in 21, and angular malalignment > 5 ° occurred in 17. The end result was excellent in 121 fractures, good in 41, fair in 28, and poor in 4.  相似文献   
54.
The efficacy of the neurotrophic peptide ORG 2766 in diabetic patients with polyneuropathy was evaluated in a double-blind, placebo-controlled, multicentre trial. One hundred and twenty four patients were randomised in five groups to receive 0.1, 0.4, 2 or 5 mg ORG 2766 or placebo, once daily, administered subcutaneously 52 weeks. Thermal discrimination thresholds (TDT) and vibration perception thresholds (VPT), motor and sensory nerve conduction velocity, Hoffmann reflex, heart rate variation during deep breathing and heart rate response after standing up, neurological examination score and neuropathic symptom score were determined at baseline and after 17, 34 and 52 weeks of treatment. Of the nerve function indices studied, at week 52 the TDTwarmth of the hand in the ORG 2766 0.1, 0.4 and 5 mg groups and the TDTcold of the foot in the ORG 2766 0.1 and 0.4 mg groups significantly improved compared with placebo. Further significant improvement as compared with placebo was observed in the paraesthesia score at week 34 and week 52 in the ORG 2766 2 mg group. Only at week 34 had both the heartbeat variation during deep breathing and the VPT of the foot in the ORG 2766 0.1 mg group improved significantly, compared with placebo. No further statistically significant differences were observed at time for the other measures. No adverse reactions were observed. The only recorded drug-induced side effect was pain at the injection site. Taking all measures of efficacy into account, the statistically significant results observed did not show consistency within each measure. Therefore, it is concluded that ORG 2766, in contrast to earlier reports, is not effective in treating diabetic polyneuropathy.  相似文献   
55.
Almost 90% of primary acute pericarditis are idiopathic. Between specifics forms, a very low percentage of cases are due to chronic rheumatic diseases. A case of adult Still's disease (juvenile chronic rheumatoid arthritis) with acute pericarditis being the first clinical manifestation (besides fever and general syndrome) is presented. Therapy with oral prednisone was rapidly effective, and pericardial effusion resolved after 3 weeks of treatment, as echocardiography showed.  相似文献   
56.
Inherited defects of the natural coagulation inhibitors predispose patients to thrombosis. These disorders have similar clinical presentations with a strong family history of thrombosis, episodes of recurrent venous thromboembolism, beginning in early adulthood. We report a case of upper gastrointestinal bleeding in a patient with portal hypertension due to portal-vein thrombosis secondary to hereditary protein C deficiency, an association that has seldom been reported.  相似文献   
57.
OBJECTIVE. To study the effects of a novel A-type retrovirus, detected in cocultures of lip biopsy specimens from Sj?gren's syndrome (SS) patients and a human T cell line, on the infected T cells. METHODS. Interleukin-2 (IL-2) and IL-6 secretion were measured by bioassay and enzyme-linked immunosorbent assay, respectively, in the infected and noninfected cell lines. Surface antigen expression was determined by flow cytometry, using monoclonal antibodies. Protein kinase C (PKC) activity was measured using an enzyme assay kit, and calcium mobilization was assessed with a fluorescent probe. RESULTS. Infected cells expressed less CD4 and IL-6 receptor, but more HLA-DR, compared with noninfected cells. Infected cells also produced less IL-2 and displayed reduced PKC activation and calcium mobilization. A similar defect in calcium mobilization was detected in T cells from SS patients. CONCLUSION. These data suggest a possible involvement of the newly described retrovirus in T cell abnormalities.  相似文献   
58.
59.
The extrusion of a pacemaker, due to infectious or mechanical problems, is a condition that usually requires the removal of the device and implantation of a new pacemaker. A case is presented in which an extruded pacemaker was successfully salvaged using the greater omentum as a wrap-around pedicled flap. The current protocol for salvaging exposed pacemakers at the authors' center is described.  相似文献   
60.
The mapping of 5-HT2 receptors in the brain using functional imaging techniques has been limited by a relative lack of selective radioligands. Iodine-123 labelled 4-amino-N-[1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide (123I-5-I-R91150 or123I-R93274) is a new ligand for single-photon emission tomography (SPET), with high affinity and selectivity for 5-HT2A receptors. This study reports on preliminary123I-5-I-R91150 SPET, wholebody and blood distribution findings in five healthy human volunteers. Maximal brain uptake was approximately 2% of total body counts at 180 min post injection (p.i.). Dynamic SPET sequences were acquired with the brain-dedicated, single-slice multi-detector system SEM-810 over 200 min p.i. Early peak uptake (at 5 min p.i.) was seen in the cerebellum, a region free from 5HT2A receptors. In contrast, radioligand binding in the frontal cortex increased steadily over time, up to a peak at approximately 100–120 min p.i. Frontal cortex-cerebellum activity ratios reached values of 1.4, and remained stable from approximately 100 min p.i. onwards. Multi-slice SPET sequences showed a pattern of regional variation of binding compatible with the autoradiographic data on the distribution of 5-HT2A receptors in (cerebral cortex>striatum>cerebellum). These findings suggest that123I-5-I-R91150 may be used for the imaging of 5-HT2A receptors in the living human brain with SPET.  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