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   6061篇
  免费   481篇
  国内免费   52篇
耳鼻咽喉   41篇
儿科学   269篇
妇产科学   113篇
基础医学   763篇
口腔科学   111篇
临床医学   793篇
内科学   1462篇
皮肤病学   101篇
神经病学   584篇
特种医学   401篇
外国民族医学   2篇
外科学   818篇
综合类   101篇
一般理论   12篇
预防医学   487篇
眼科学   37篇
药学   229篇
中国医学   3篇
肿瘤学   267篇
  2021年   81篇
  2019年   51篇
  2018年   64篇
  2016年   59篇
  2015年   99篇
  2014年   121篇
  2013年   165篇
  2012年   244篇
  2011年   238篇
  2010年   142篇
  2009年   120篇
  2008年   216篇
  2007年   242篇
  2006年   232篇
  2005年   257篇
  2004年   237篇
  2003年   197篇
  2002年   239篇
  2001年   195篇
  2000年   178篇
  1999年   174篇
  1998年   84篇
  1997年   82篇
  1996年   94篇
  1995年   74篇
  1994年   83篇
  1993年   71篇
  1992年   161篇
  1991年   149篇
  1990年   161篇
  1989年   183篇
  1988年   148篇
  1987年   150篇
  1986年   129篇
  1985年   111篇
  1984年   104篇
  1983年   71篇
  1981年   46篇
  1980年   51篇
  1979年   65篇
  1978年   68篇
  1977年   56篇
  1976年   65篇
  1975年   59篇
  1974年   67篇
  1973年   54篇
  1972年   48篇
  1971年   59篇
  1970年   55篇
  1969年   55篇
排序方式: 共有6594条查询结果,搜索用时 15 毫秒
41.
42.
43.
Ivemark syndrome is a rare sporadic or autosomal recessive disorder characterized by pancreatic fibrosis, renal dysplasia and hepatic dysgenesis. There have been no data describing the renal changes during embryologic development in this syndrome. In this report, we document the pathological findings of the kidney in three subjects with Ivemark syndrome: 6 months, 21 weeks and 16 weeks, respectively. Kidneys of subjects and age-matched controls were examined by light microscopy and immunohistochemically for cytokeratin, AE1/AE3 and epithelial membrane antigen. Renal dysplasia in Ivemark syndrome becomes apparent at 16 weeks of gestation and progresses thereafter in severity. It is characterized by disturbance in glomerular differentiation, delay in tubular differentiation and abnormal expression of epithelial markers in glomeruli and tubules. Cytokeratin and epithelial membrane antigen expression of cysts is similar to that of the collecting ducts.  相似文献   
44.
45.
46.
One hundred nineteen patients at rural community mental health centers were divided into three diagnostic groups and compared to determine if alcoholic and nonalcoholic patients differ significantly in terms of psychopathology. The three diagnostic groups were primary diagnosis of alcoholism (N = 34), primary diagnosis of emotional disturbance (N = 39), and "other" diagnoses (N = 46). These groups were compared with respect to demographic variables, alcohol drinking patterns, psychopathology, and attitude toward treatment. The alcoholic patient group tended to be single, male, and inpatients; while the nonalcoholic group tended to be married, female, and outpatients. These groups differed significantly with respect to alcohol consumption and drinking patterns and effects, but did not differ significantly with respect to their attitudes toward mental illness or their MMPI profiles. The results of the "other" diagnostic group generally fell between those of the alcoholic and nonalcoholic groups, suggesting that it was a heterogeneous group of subjects. The total subject population evidenced elevated MMPI profiles, indicating the presence of a high level of psychopathology, but there was no clear distinction between the alcoholics and the other groups in terms of type or degree of psychopathology. Implications for treatment are discussed.  相似文献   
47.
Intravascular papillary endothelial hyperplasia is an interesting endothelial proliferation, the nature of which has aroused some controversy. Five cases were studied by light microscopy and by immunohistochemistry using antibodies to Factor VIII-related antigen (FVIII-rAg), ferritin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and vimentin and were compared with conventional intravascular organizing thrombi. The results show a similar progression of the immunophenotype of the endothelial cells in both entities: they are initially positive for ferritin, then acquire vimentin positivity and only display FVIII-rAg positivity in advanced ("mature") lesions. This suggests that intravascular endothelial hyperplasia is closely related to organizing thrombi and is probably a peculiar form thereof.  相似文献   
48.
Search consultants say they have difficulty identifying qualified minority candidates. Here are some suggestions for minority healthcare executives looking to advance their careers.  相似文献   
49.
The visceral adiposity syndrome in Japanese-American men   总被引:1,自引:0,他引:1  
Japanese-Americans have an increased prevalence of non-insulin-dependent diabetes mellitus and coronary heart disease when compared to native Japanese. This increase has been associated with fasting hyperinsulinemia, hypertriglyceridemia, and low plasma levels of high-density lipoprotein (HDL) cholesterol. The purpose of this study was to examine the relationship of both visceral adiposity and insulin resistance to this metabolic syndrome and to the presence of a predominance of small, dense low-density lipoprotein (LDL) particles (LDL subclass phenotype B) that has been associated with increased atherogenic risk. Six Japanese-American men with non-insulin-dependent diabetes, each receiving an oral sulfonylurea, were selected. One or 2 nondiabetic Japanese-American men, matched by age and body mass index, were selected for each diabetic subject, giving a total of 9 nondiabetic men. Diabetic subjects had significantly higher fasting plasma glucose (p=0.0007) and lower insulin sensitivity (SI, p=0.018) using the minimal model technique than nondiabetic subjects matched for body mass index. Six men (2 with diabetes) had LDL phenotype A and 8 (4 with diabetes) had phenotype B. One nondiabetic subject had an intermediate low-density lipoprotein pattern. Significantly greater amounts of intra-abdominal fat (p=0.045) measured by computed tomography were found in the men with phenotype B while fasting insulin (p=0.070) and triglycerides (p=0.051) tended to be higher. free fatty acids (r=0.677), LDL density (relative flotation rate, r=-0.803), and plasma HDL-cholesterol (r=-0.717). SI was significantly correlated only with plasma free fatty acids (r=-0.546) and tended to be correlated with hepatic lipase activity (r=-0.512, p=0.061). In conclusion, these observations indicate that in non-obese Japanese-American men, the metabolic features of the so-called insulin resistance syndrome, including LDL phenotype B, are more strongly correlated with visceral adiposity than with SI. It may therefore be more appropriate to call this the visceral adiposity syndrome. Although questions concerning mechanisms still remain, we postulate that visceral adiposity plays a central role in the development of many of the metabolic abnormalities, including LDL subclass phenotype B, that occur in this metabolic syndrome.  相似文献   
50.
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