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   2063893篇
  免费   156320篇
  国内免费   3916篇
耳鼻咽喉   27286篇
儿科学   69274篇
妇产科学   58187篇
基础医学   304425篇
口腔科学   58206篇
临床医学   191238篇
内科学   399146篇
皮肤病学   45674篇
神经病学   165360篇
特种医学   77943篇
外国民族医学   554篇
外科学   299155篇
综合类   46184篇
现状与发展   3篇
一般理论   919篇
预防医学   168601篇
眼科学   47080篇
药学   150460篇
  9篇
中国医学   3783篇
肿瘤学   110642篇
  2018年   21843篇
  2017年   16813篇
  2016年   18749篇
  2015年   21447篇
  2014年   29573篇
  2013年   45386篇
  2012年   60776篇
  2011年   64913篇
  2010年   38109篇
  2009年   36304篇
  2008年   60868篇
  2007年   64987篇
  2006年   64970篇
  2005年   63076篇
  2004年   61042篇
  2003年   58635篇
  2002年   56752篇
  2001年   91880篇
  2000年   94037篇
  1999年   79176篇
  1998年   22483篇
  1997年   20427篇
  1996年   20734篇
  1995年   19787篇
  1994年   18394篇
  1993年   17184篇
  1992年   63448篇
  1991年   62293篇
  1990年   60974篇
  1989年   58915篇
  1988年   54070篇
  1987年   53729篇
  1986年   50787篇
  1985年   48481篇
  1984年   36775篇
  1983年   31685篇
  1982年   18948篇
  1981年   17146篇
  1979年   34594篇
  1978年   25284篇
  1977年   21228篇
  1976年   19908篇
  1975年   21227篇
  1974年   25815篇
  1973年   25156篇
  1972年   23621篇
  1971年   21984篇
  1970年   20611篇
  1969年   19347篇
  1968年   17994篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The effects of clinically successful periodontal therapy were studied in juvenile periodontitis (JP) and rapidly progressive periodontitis (RP) patients and compared with periodontally healthy subjects (HS). Serum samples were obtained in 35 HS prior to the study and in 12 of these subjects 3-4 years later. Serum samples were obtained from 50 JP patients initially, 9 subjects immediately following surgical therapy and 29 of these subjects 3-4 years later. RP patients provided 46 initial serum samples, 9 following therapy and 27 samples 3-4 years later. Antibody levels were determined utilizing a standardized enzyme-linked immunosorbent assay with Bacteroides gingivalis, B. ochracea, Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans serving as antigens. The JP patients showed an initial rise in antibody levels immediately following therapy followed by a significant decrease in antibody levels 3 to 4 years later. The RP patients did not show an early change in antibody levels but by 3 to 4 years post-therapy, antibody levels had significantly decreased. However, during this study, the antibody levels of JP and RP patients remained significantly higher when compared with HS patients.  相似文献   
992.
993.
Chlothorax is a rare complication of high translumbar aortography and a case is described here.  相似文献   
994.
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily.  相似文献   
995.
Studies were performed in hypercholesterolemic rabbits to determine whether the hydrophobic surfactant, Poloxalene 2930 (Pol), is of benefit under these conditions. Lipoprotein analyses plus chemical and morphologic studies of the aorta were performed to evaluate the results. In one study, rabbits were made hypercholesterolemic by dietary means and then divided into two groups and given a cholesterol-free diet with one group additionally given Pol with treatment continued for 10 weeks. Pol treatment resulted in less atherosclerosis but the mechanism for this effect was not apparent from lipoprotein analysis. In the other study 3 groups of rabbits were given a cholesterol-rich diet for 16 weeks. Two groups received Pol supplement with one of these groups receiving a dose that was too small to prevent hypercholesterolemia. In this group plus the group on diet alone comparable degrees of hypercholesterolemia were maintained throughout the study. Lipoprotein abnormalities were similar in these two groups except that those on Pol had a more normal cholesterol to apolipoprotein B ratio. The amount of atherosclerosis in both groups was mild but aortic cholesterol content was much less for the Pol group. It is concluded that Pol limits cholesterol accumulation in the aortic wall of hypercholesterolemic rabbits and can retard the development of atherosclerosis.  相似文献   
996.
Biliopancreatic diversion is a very effective method for weight reduction. In some instances it is too effective and needs to be revised.  相似文献   
997.
IgG-maleimide peroxidase, Fab'-maleimide peroxidase, polymer and monomer types of Fab'-periodate peroxidase were prepared from an antibody against rat lipoamide dehydrogenase, a component of the pyruvate dehydrogenase complex which is located in mitochondria. They were examined for immunohistochemical staining of the rat kidney. Fab'-maleimide peroxidase was the best for staining mitochondrial protein. IgG-maleimide peroxidase and the monomer type of Fab'-periodate peroxidase had the same intensity of staining. The polymer type of Fab'-periodate peroxidase could not stain the lipoamide dehydrogenase.  相似文献   
998.
A significant increase of LDL-apolipoprotein B by 13% and LDL-cholesterol by 19% was observed in a group of 9 patients with hyperlipoproteinaemia Type III after bezafibrate treatment. Additional administration of colestipol caused a significant decrease of both LDL-apolipoprotein B by 18% and LDL-cholesterol by 25%. In 10 patients of hyperlipoproteinaemia Type IIb a significant decrease of both LDL-apolipoprotein B by 28% and LDL-apolipoprotein B by 18% was observed after bezafibrate therapy. When bezafibrate was given together with colestipol a further decrease of both LDL-cholesterol by 17% and LDL-apolipoprotein B by 16% occurred. HDL-cholesterol concentration increased significantly in both groups of hyperlipaemic patients during therapy. This may be the effect of both bezafibrate and colestipol. It is concluded that bile acid resins may effectively prevent the LDL-cholesterol concentration increase observed sometimes after clofibrate analogues.  相似文献   
999.
1000.
Changes in the height, weight, body mass index, triceps skinfold, and arm and estimated midarm muscle circumferences in lower socioeconomic Mexican American children, 6 through 17 years of age, from Brownsville, Texas, were documented on the basis of surveys done in 1972 and 1983. With the exception of height in youths ages 14-17, all parameters show gains at most ages, and in particular an increase in fatness. Brownsville Mexican American youth are similar in height, weight, and the body mass index to Mexican American youth in other areas of Texas. These trends confirm the large proportion of relatively short but heavy children among Mexican Americans.  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