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   339619篇
  免费   22018篇
  国内免费   7556篇
耳鼻咽喉   4067篇
儿科学   9536篇
妇产科学   6551篇
基础医学   27554篇
口腔科学   7929篇
临床医学   37265篇
内科学   42494篇
皮肤病学   4562篇
神经病学   19322篇
特种医学   7834篇
外国民族医学   31篇
外科学   36362篇
综合类   50600篇
现状与发展   12篇
一般理论   29篇
预防医学   35028篇
眼科学   5270篇
药学   30082篇
  385篇
中国医学   30814篇
肿瘤学   13466篇
  2023年   5461篇
  2022年   9680篇
  2021年   13237篇
  2020年   12305篇
  2019年   18251篇
  2018年   15787篇
  2017年   12699篇
  2016年   10203篇
  2015年   9534篇
  2014年   19635篇
  2013年   21194篇
  2012年   18043篇
  2011年   19567篇
  2010年   15715篇
  2009年   14421篇
  2008年   14047篇
  2007年   14506篇
  2006年   12654篇
  2005年   11007篇
  2004年   8954篇
  2003年   7864篇
  2002年   6182篇
  2001年   5539篇
  2000年   4579篇
  1999年   3980篇
  1998年   3223篇
  1997年   3090篇
  1996年   2671篇
  1995年   2569篇
  1994年   2478篇
  1993年   1974篇
  1992年   2007篇
  1991年   1731篇
  1990年   1539篇
  1989年   1372篇
  1988年   1302篇
  1987年   1120篇
  1985年   3784篇
  1984年   4795篇
  1983年   3340篇
  1982年   3800篇
  1981年   3547篇
  1980年   3156篇
  1979年   2905篇
  1978年   2533篇
  1977年   1906篇
  1976年   2150篇
  1975年   1631篇
  1974年   1429篇
  1973年   1277篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
The intrauterine position occupied by a rodent fetus influences the amount of testosterone to which it is exposed before birth. Animals that are gestated between two male fetuses (2M) are exposed to higher circulating levels of testosterone than are animals positioned between two female fetuses (2F) and there are reliable differences in the reproductive physiology and behavior of 2M and 2F animals when adult. To determine whether intrauterine position modifies development of the central nervous system, we examined the sexually dimorphic spinal nucleus of the bulbocavernosus (SNB) in male and female gerbils from known intrauterine positions. We found that adult 2M female gerbils had 16% more SNB motoneurons than did 2F females. 2M males did not differ from 2F males in SNB motoneuron number, but the bulbocavernosus muscle, which is innervated by SNB motoneurons, was approximately 50% larger in 2M than in 2F males. These data indicate that intrauterine position can influence the morphology of the sexually dimorphic SNB neuromuscular system.  相似文献   
102.
We report the case of a 44-year-old male with a 10-year history of manifestations of the rare form of bullous systemic lupus erythematosus (SLE) with coexisting antiphospholipid syndrome (APS) that remained undiagnosed until thrombotic-embolic episodes appeared and high titres of anticardiolipin (ACL) antibodies were detected. The patient fulfilled the criteria for SLE and the atypical cutaneous manifestations together with histopathological changes and a favourable response to sulphones were the grounds for the diagnosis of the bullous variety of SLE. Treatment with prednisolone, acenocoumarol and dapsone resulted in marked clinical improvement, reduction in antinuclear antibodies (ANAs) and normalization of ACL antibody titres.  相似文献   
103.
Nerve conduction as a means of estimating early post-mortem interval   总被引:2,自引:0,他引:2  
Summary Methods in current practice for ascertaining time of death are largely based on the cooling of the body after death and are somewhat unreliable. A theoretica relationship is known to exist between the decline in the properties defining nerve conduction and time after death caused by the gradual cessation of metabolic activity in nerves. A number of such properties were measured in rats during life and after death. In most cases the relationship was found to be inconsistent. The chronaxie of the strength duration curve for the sciatic nerve was, however, found to increase consistently and reproducibly in a linear fashion over the first 90 min after death to a plateau value which was maintained beyond 135 min. These findings are discussed as the possible basis of a forensic method of determining the duration of the “post mortem interval” within the first few hours after death.   相似文献   
104.
刘素霞  黑连荣 《北京医学》1994,16(6):340-342
经临床鉴定静脉内注射小儿氨基酸对治疗胎儿宫内发育迟缓具有肯定效果。在B超监视下,使用小儿氨基酸的孕妇组于用药期间,胎儿生长参数BPD和HC显著高于使用成人氨基酸的孕妇组。10例足月娩出胎儿体重均达到甚至超过2.5kg。由此得出结论:使用小儿氨基酸注射液对于改善胎儿宫内发育迟缓优于成人氨基酸。  相似文献   
105.
106.
Abstract: The efficacy and safety of recombinant human erythropoietin (rhEPO) were tested when given subcutaneously (s.c.) in an escalating dose of 2000–10,000 units (U) daily in 60 patients with cancer-related anaemia (CRA). A positive response, defined as an increase in haemoglobin more than 2 g/dl and independence of blood transfusions, was observed in 23 of 48 evaluable patients (48%) within a median of 8 wk. In detail, rhEPO corrected anaemia in 11 of 14 patients (79%) with malignant lymphoma, in 8 of 15 patients (53%) with multiple myeloma and in 4 of 10 patients (40%) with a solid tumour. The median dose of rhEPO in successful cases was 5000 U daily. Four patients with agnogenic myeloid metaplasia and 5 with myelodysplastic disorder failed to respond to rhEPO. No patient had any severe side effects. Pretreatment serum erythropoietin levels appeared to be a weak predictor for response to rhEPO treatment. In conclusion, rhEPO seems to be safe and effective in correcting CRA in certain groups of patients.  相似文献   
107.
Hepatic venous outflow tract obstruction, Budd-Chiari syndrome (BCS), leads to portal hypertension and to the development of collaterals that bypass the obstruction. Described here is a BCS patient with an unusually large transdiaphragmatic collateral between the left hepatic and left innominate veins, which decompressed the oesophageal varices. This has not been reported earlier in the literature.  相似文献   
108.
We report satisfactory results with a new operative treatment, conducted via an extensive anterolateral approach, involving 360 degree circumferential capsulotomy, for residual subluxation in congenital dislocation of the hip (CDH). Long-term radiographic results of this procedure (group A) were compared retrospectively with the results of partial capsulotomy (group B), which preserved the posteroinferior joint capsule. The mean center edge angle in group A (22.5°) was greater than that in group B (16.0°). Satisfactory results were achieved in 11 of 15 hips (73%) (Severin class I or II) in group A, and in 5 of 12 hips (42%) in group B. These results suggest that whole circumferential capsulotomy can remove obstacles to complete reduction, and that acetabular development can be expected in hips reduced by the procedure, without the performance of innominate osteotomy. We believe that our technique is a useful alternative for the treatment of residual subluxation in CDH.  相似文献   
109.
Medical students are allocated little curriculum time for exposure to expert systems. ESTA, a computer model of an expert system, was developed to make best use of this time. The nature of the students' interaction with ESTA is described, and their reactions to the expert system concepts and the place of expert systems in medicine are presented. A discussion of these reactions draws some conclusions about teaching expert systems in particular, and computers in general, in the basic medical course.  相似文献   
110.
A structured clinical examination has been an integral component of the final-year examinations conducted by the Departments of Medicine and Surgery at the University of Adelaide for the last 8 years. It has been used as an alternative to the traditional clinical examination. This paper describes the results of ongoing student and examiner surveys carried out to determine their views and satisfaction with this new approach. It also briefly discusses the feasibility of introducing such an examination into a conventional medical school environment. The surveys showed a remarkable level of acceptance and support by both students and examiners. This positive reaction has been maintained over the 8-year period. The main reasons seem to be its perceived relevance and fairness. Students also appear to be directing their learning in a direction thought desirable by teachers. No significant problems have been encountered with the practical implementation of the method.  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