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   5144篇
  免费   465篇
  国内免费   299篇
耳鼻咽喉   65篇
儿科学   72篇
妇产科学   58篇
基础医学   616篇
口腔科学   183篇
临床医学   579篇
内科学   866篇
皮肤病学   53篇
神经病学   254篇
特种医学   246篇
外国民族医学   1篇
外科学   673篇
综合类   666篇
现状与发展   3篇
一般理论   1篇
预防医学   304篇
眼科学   107篇
药学   559篇
  1篇
中国医学   309篇
肿瘤学   292篇
  2024年   12篇
  2023年   81篇
  2022年   202篇
  2021年   221篇
  2020年   155篇
  2019年   173篇
  2018年   183篇
  2017年   145篇
  2016年   142篇
  2015年   188篇
  2014年   258篇
  2013年   241篇
  2012年   371篇
  2011年   395篇
  2010年   228篇
  2009年   186篇
  2008年   239篇
  2007年   325篇
  2006年   222篇
  2005年   245篇
  2004年   149篇
  2003年   151篇
  2002年   139篇
  2001年   128篇
  2000年   132篇
  1999年   119篇
  1998年   91篇
  1997年   85篇
  1996年   58篇
  1995年   64篇
  1994年   49篇
  1993年   52篇
  1992年   65篇
  1991年   53篇
  1990年   48篇
  1989年   47篇
  1988年   43篇
  1987年   33篇
  1986年   31篇
  1985年   23篇
  1984年   17篇
  1983年   10篇
  1980年   8篇
  1979年   9篇
  1978年   12篇
  1977年   12篇
  1974年   10篇
  1973年   9篇
  1972年   8篇
  1968年   8篇
排序方式: 共有5908条查询结果,搜索用时 15 毫秒
31.
From the femoral heads of nine cases of advanced osteoarthritis of hip joint, three categories of granulation tissues with different colors (bright red, dark-red and white granulation tissues) and texture were obtained. After processing, the specimens were observed under scanning electron microscope and transmission electron microscope. With transformation of the granulation tissues from bright red to white, the collagen fibers therein contained gradually changed from fine to thick ones. Nevertheless, the cellular components in these three types of granulation tissues always possessed the characteristics of both fibroblasts and chondrocytes, i.e., fibroblastic configuration with pericellular Type I collagen fibrils bearing 64 nm periodicity; and chondrocytic scallop-shaped cytoplasmic membrane with intracytoplasmic fat droplets and glycogen granules and pericellular Type II collagen fibrils. All these indicated that in osteoarthritis of hip joints, the granulation tissues of the femoral heads transformed eventually into fibrocartilage, irrespective of their color and texture.
  相似文献   
32.
骨的原发性恶性纤维组织细胞瘤少见而诊断困难。本文通过11例临床、X 线和病理分析,确认用三结合方法是正确诊断的依据,而病理检查方能确诊。其特点是同时存在组织细胞样细胞及成纤维细胞样细胞。截肢仍为治疗的主要方法。  相似文献   
33.
Micturition and continence involve the coordination of complex neural events between the central and peripheral nervous systems. An understanding of these events provides a foundation for the treatment of voiding disorders in women such as stress urinary incontinence, urge incontinence and interstitial cystitis. The purpose of this paper is to comprehensively review the neuroanatomy, enurophysiology and neuropharmacology of micturition and continence. However, a brief section discussing clinical correlations will follow each of these topics to help integrate the basic science with clinical obervations.  相似文献   
34.
亮氨酸脑啡肽的电子结构及构效关系研究   总被引:1,自引:0,他引:1  
对亮氨酸脑啡肽进行了量子化学(INDO)计算,研究其电子结构特征,讨论其活性部位、作用机理及构效关系。同吗啡和R31833进行了活性部位的电子结构与空间结构比较,推断它们的活性药效结构具有共同特点,与阿片受体相互作用时作用方式相同,作用部位有对应关系,因而具有相同的药理性质。  相似文献   
35.
36.
1. The radioligand [125I]-endothelin was used to map receptors for endothelin in rat adrenal gland using in vitro autoradiography and computerized densitometry. 2. In the adrenal, a high density of binding was found in the adrenal medulla (binding affinity constant 0.18 +/- 0.11 X 10(9)M-1) and zona glomerulosa (binding affinity constant 0.18 +/- 0.07 X 10(9)M-1). Binding was low to undetectable in the zona fasciculata and zona reticularis. Unrelated peptides did not displace endothelin. 3. These results provide evidence of endothelin receptor distribution in adrenal gland and suggest that endothelin might exert multiple actions in the adrenal gland on catecholamine and aldosterone biosynthesis and secretion.  相似文献   
37.
The healing of standardized fracture of rabbit radius was expedited as a result of treatment with low-power CO2 laser irradiation. Observation with transmission electron microscope revealed the following favorable effects of CO2 laser irradiation: The red blood cells were induced to disintegrate, thus promoting the absorption of the hematoma. The macrophages emerged early and increased in number so that debridement of the necrotic tissues was enhanced. The fibroblasts were more active in producing the fibrous callus. The chondrocytes were unusually active in forming bone tissues. The early and sustained appearance of osteoclasts favored the bone remodeling process. Increased capillary formation endowed the fracture healing with rich blood supply. Deposition of calcium salts took place early.  相似文献   
38.
39.
40.
Inapparent infection of hepatitis A virus   总被引:2,自引:0,他引:2  
To detect inapparent infection with hepatitis A virus, serial sera were collected from patients with hepatitis A and their contacts in two waterborne epidemics in China. Epidemic 1 occurred in a rural village near Hangzhou during August 1978-January 1979, and epidemic 2 took place in a rural primary school in Pinghu County in Zhejiang in April-May 1985. These sera were tested for antibodies against hepatitis A virus (anti-HAV), serum glutamic pyruvic transaminase (SGPT) activity, and icteric index. Feces also were collected in epidemic 1 to test for hepatitis A virus antigen. Both anti-HAV immunoglobulin M (IgM) and total anti-HAV were assayed in sera from "healthy persons" (symptomless persons without icterus and with normal SGPT level) who were in close contact with hepatitis A patients. In epidemic 1, among 18 "healthy persons", 12 were anti-HAV IgM positive, two were immune, and four susceptibles escaped infection. In epidemic 2, among 32 "healthy children", three were anti-HAV IgM positive, five had been infected by hepatitis A virus in the past, and 24 were not infected. These results demonstrate that inapparent infections occur along with overt and subclinical infections during epidemics of hepatitis A. The proportions of inapparent, subclinical, and overt infections were, respectively, 34.3%, 45.7%, and 20% in epidemic 1, and 25%, 50%, and 25% in epidemic 2. In addition, hepatitis A virus particles were demonstrated in the feces of all infected subjects who were examined and who included all levels of clinical response. These particles were identified with immuno-electron microscopy and enzyme-linked immunoassay.  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