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   1393篇
  免费   60篇
  国内免费   54篇
耳鼻咽喉   25篇
儿科学   54篇
妇产科学   47篇
基础医学   160篇
口腔科学   39篇
临床医学   117篇
内科学   210篇
皮肤病学   31篇
神经病学   107篇
特种医学   46篇
外科学   200篇
综合类   61篇
预防医学   85篇
眼科学   57篇
药学   153篇
中国医学   4篇
肿瘤学   111篇
  2023年   12篇
  2022年   32篇
  2021年   48篇
  2020年   22篇
  2019年   26篇
  2018年   31篇
  2017年   23篇
  2016年   30篇
  2015年   36篇
  2014年   45篇
  2013年   67篇
  2012年   77篇
  2011年   71篇
  2010年   58篇
  2009年   34篇
  2008年   80篇
  2007年   106篇
  2006年   81篇
  2005年   68篇
  2004年   46篇
  2003年   46篇
  2002年   50篇
  2001年   28篇
  2000年   32篇
  1999年   31篇
  1998年   16篇
  1996年   6篇
  1995年   10篇
  1994年   6篇
  1993年   8篇
  1992年   14篇
  1991年   15篇
  1990年   19篇
  1989年   24篇
  1988年   21篇
  1987年   13篇
  1986年   13篇
  1985年   10篇
  1984年   10篇
  1983年   6篇
  1980年   6篇
  1979年   15篇
  1978年   7篇
  1977年   5篇
  1976年   13篇
  1974年   16篇
  1973年   8篇
  1972年   7篇
  1971年   10篇
  1970年   7篇
排序方式: 共有1507条查询结果,搜索用时 15 毫秒
1.
2.
We evaluated the efficacies of five treatment procedures for eliminating ascorbate interference in the enzymatic determination of urinary oxalate. Aliquots of urine samples, containing different amounts of added ascorbate and oxalate, were individually subjected to ferric chloride, sodium nitrite, sodium periodate, charcoal, or ascorbate oxidase treatment to eliminate ascorbate interference. Oxalate contents of the urine samples were then determined by a banana oxalate oxidase-horseradish peroxidase-linked assay with 3-methyl-2-benzothiazolinone hydrazone and 3-(dimethylamino)benzoic acid as chromogens. Only those urine samples treated with ascorbate oxidase or charcoal consistently gave recovery of oxalate close to 100%. Treatment with other reagents, though improving the recovery of oxalate, gave inconsistent results. On the basis of these data, we describe procedures for simply and reliably assaying oxalate by using banana oxalate oxidase.  相似文献   
3.
4.
Two cases of bipartite tarsal navicular bone are presented. The radiographic and computed tomography (CT) findings of this anatomical variant are described. Correct recognition of this entity is important, both because it may be the cause of symptoms perse, and because it may be misdiagnosed as a fracture. When plain films are not diagnostic, CT scanning is helpful in distinguishing between a fracture and this variant.  相似文献   
5.
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.  相似文献   
6.
Objectives: to evaluate the diagnostic value of clinical symptoms and signs in enteric fever and to propose a clinical diagnostic criterion. Design: Prospective observational study Setting: Kathmandu Medical College, Teaching Hospital, Kathmandu, Nepal Materials and methods: febrile patients with clinical diagnosis of enteric fever were included in the study with the aim of confirming diagnosis with blood culture, or bone marrow culture and evaluating the diagnostic accuracy of various clinical signs and symptoms. Results: 64% of the clinically diagnosed cases had blood/ bone marrow culture positive. The diagnostic accuracy of the various symptoms and signs excluding fever was between 42%-75.5%. Majority of the symptom and sign did not have very high diagnostic accuracy. Hence a diagnostic criterion was proposed and clinical features with diagnostic accuracy more than 50% were taken into consideration. Major criteria included fever with diagnostic accuracy of 64%, headache with accuracy of 75.5% and relative bradycardia with an accuracy of 66%. Minor criteria included vomiting, diarrhoea, Splenomegaly, chills and abdominal pain /discomfort with diagnostic accuracy of 57%, 55%, 55%, 53% and 51% respectively. Finally after combination of various major and minor criteria a final diagnostic criterion was proposed having an accuracy of 66% and including both major and minor clinical symptom and sign. Conclusion: clinical diagnosis of enteric fever will be very helpful in a country like ours. Though none of the clinical symptoms and sign have very high diagnostic accuracy a diagnostic criteria may be helpful. Criteria including both major and minor signs and symptoms would be the most appropriate diagnostic tool as it includes the important abdominal symptoms and signs of enteric fever. Key words: enteric fever, clinical features, diagnostic criteria.  相似文献   
7.
8.
Peroneus quartus muscle: MR imaging features   总被引:2,自引:0,他引:2  
  相似文献   
9.
A case of spontaneous rupture of the oesophagus (Boerhaave's syndrome) following acute myocardial infarction is presented. Conservative management with chest drainage and parenteral, later jejunostomy, feeding was successful. Progress was monitored with methylene blue swallow. A review of the literature revealed only two previous cases of this type.  相似文献   
10.
In a double-blind prospective study, 29 endogenously depressed patients (RDC) were randomized into sinusoidal wave (SW) and brief-pulse (BP) electroconvulsive therapy (ECT) groups. Bilateral modified treatments were administered on alternate days, three per week, and the treatment variables of current dosage and seizure duration were monitored for each treatment. Significantly more patients responded to SW than to BP ECT, but a comparable number of treatments was required to produce this response in the two groups. There was no difference in clinical or treatment variables between the SW and the BP groups, nor between ECT responders and nonresponders, with the exception that the SW-treated patients received larger doses of current per treatment than did the BP patients. For endogenous depression treated with ECT, we conclude that cumulative seizure duration may not be a parameter of significance, that overall rate of recovery in ECT responders is independent of stimulus waveform, and that some depressives may respond to SW but not to BP ECT. We suggest that the antidepressant effect of the ECT seizure may be characterized by a therapeutic window in current requirements; alternatively, a putative response threshold (again in terms of current requirement) may exist, which is higher in some patients than in others.  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