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   6872篇
  免费   422篇
  国内免费   23篇
耳鼻咽喉   98篇
儿科学   626篇
妇产科学   116篇
基础医学   858篇
口腔科学   132篇
临床医学   441篇
内科学   1421篇
皮肤病学   304篇
神经病学   349篇
特种医学   326篇
外科学   672篇
综合类   181篇
一般理论   3篇
预防医学   403篇
眼科学   245篇
药学   564篇
中国医学   24篇
肿瘤学   554篇
  2023年   50篇
  2022年   123篇
  2021年   227篇
  2020年   164篇
  2019年   193篇
  2018年   222篇
  2017年   141篇
  2016年   163篇
  2015年   176篇
  2014年   297篇
  2013年   335篇
  2012年   460篇
  2011年   442篇
  2010年   271篇
  2009年   215篇
  2008年   305篇
  2007年   315篇
  2006年   301篇
  2005年   280篇
  2004年   256篇
  2003年   219篇
  2002年   195篇
  2001年   148篇
  2000年   125篇
  1999年   120篇
  1998年   70篇
  1997年   42篇
  1996年   48篇
  1995年   33篇
  1994年   44篇
  1993年   41篇
  1992年   87篇
  1991年   93篇
  1990年   96篇
  1989年   84篇
  1988年   71篇
  1987年   81篇
  1986年   60篇
  1985年   61篇
  1984年   65篇
  1983年   47篇
  1982年   64篇
  1981年   75篇
  1980年   72篇
  1979年   55篇
  1978年   33篇
  1977年   26篇
  1976年   34篇
  1973年   31篇
  1970年   26篇
排序方式: 共有7317条查询结果,搜索用时 15 毫秒
21.
22.
23.
Subjects from Muria gond tribal community (n = 258) as well as from Delhi (n = 100) were classified according to ABO blood groups, and were also assayed for malarial antibodies by ELISA technique. The distribution of ABO blood groups did not differ significantly in Muria gonds and Delhi subjects. Within Muria gonds the observed frequency of ABO blood groups did not differ significantly from the expected values. No significant difference was observed in the rate of seropositivity for malarial antibodies among subjects with different blood groups. Malarial parasitaemia, although observed more in individuals with blood group A, did not differ significantly as compared with other blood groups. We conclude that ABO blood groups do not show differential susceptibility to malaria.  相似文献   
24.
Protein A is an immunostimulating glycoprotein obtained from Staphylococcus aureus Cowan I. Its antitumour activity is proven in various tumour models. Its ability to provide protection against tumour initiation by the chemical carcinogen 7,12-dimethylbenzanthracene (DMBA) has been investigated in the present study using a mouse skin model of two-stage carcinogenesis. Protein A was administered intraperitoneally (1 microgram/animal 20 g body wt.) twice a week for 2 weeks, prior to initiation by DMBA. The promotion was performed by twice weekly applications of 12-O-tetradecanoyl phorbol-13-acetate (TPA) (3 or 5 micrograms/animal in 100 microliters acetone). Protein A provided significant protection to animals from DMBA-induced tumour initiation as was observed by the decrease in cumulative number of tumours, percent of animals developing tumours, number of tumours per animal and rate of tumour growth. Our data indicate that protein A has anticarcinogenic properties.  相似文献   
25.
Hydatid antigen was demonstrated for the first time in the urine of patients with hydatid disease by countercurrent immunoelectrophoresis (CIEP). The antigen was detected in the concentrated urine of 7 of 16 (43.75% positive) patients with surgically confirmed hydatid disease, 4 of 10 (40% positive) patients with ultrasound-proven hydatid disease (daughter cysts or prominent septation and hydatid sands demonstrated by ultrasound), and 8 of 14 (57.14% positive) patients with clinically diagnosed (presumptive) hydatid disease. No antigen was detected in the concentrated urine from 24 patients with parasitic diseases other than hydatid disease. However, antigen was detected in 2 (8% false positive) of 25 concentrated urine samples collected from healthy control subjects (blood donors and students). These result suggest that the detection of hydatid antigen in the urine by CIEP is a simple, rapid, and noninvasive method of diagnosis of hydatid disease.  相似文献   
26.
We report a new case of Rubinstein-Taybi syndrome with a hypoplastic right kidney, persistent pulmonary hypertension, and mitral valve regurgitation. Other pertinent features included broad thumbs, broad big toes, syndactyly of the third and fourth fingers bilaterally, beaked nose, broad columella of the nose, patent ductus arteriosus, and motor and mental retardation. The testes were descended. The 3 month old patient had delayed motor and mental development corresponding to a 1 month old infant.  相似文献   
27.
28.
Hypertrophic pachymeningitis is a rare fibrosing inflamatory process involving dura mater and tentorium. In this report we are presenting contrast enhanced MRI findings of an unusual case of pachymeningitis which presented with a periorbital mass due to dural sinuses occlusion and retrograde filling of periorbital veins through superior sagittal sinus.  相似文献   
29.
30.
Due to deep seated location and presence of vital structures, the tumours of the parapharyngeal space poses difficulty in its early diagnosis, histological nature and surgical extirpation. Modes of radiological assessment in pre-computed tomography (GT) scan era were sialography of the parotid gland to see whether the tumour is of salivary origin and angiography to note the vascularity of the tumour. Post CT scan era has changed the assessment protocol. In this article, the authors have tried to make a comparative evalua?tion between non-contrast GT, GT with systemic contrast and GT sialogram in 14 cases of parapharyngeal tumours. Angiography was done only when the tumours showed marked enhancement with systemic contrast. Subsequently, 13 patients underwent surgery for removal of the mass. Application of high-resolution GT helped in not only to see the extent of the tumour but also to pinpoint the probable histologic nature.  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