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   1574488篇
  免费   149661篇
  国内免费   5481篇
耳鼻咽喉   23015篇
儿科学   51683篇
妇产科学   44507篇
基础医学   203942篇
口腔科学   42852篇
临床医学   164067篇
内科学   329556篇
皮肤病学   40689篇
神经病学   131960篇
特种医学   60124篇
外国民族医学   464篇
外科学   249217篇
综合类   32996篇
现状与发展   81篇
一般理论   487篇
预防医学   123881篇
眼科学   35470篇
药学   99546篇
  1篇
中国医学   3357篇
肿瘤学   91735篇
  2021年   13938篇
  2020年   13322篇
  2019年   13838篇
  2018年   25009篇
  2017年   21612篇
  2016年   24001篇
  2015年   25908篇
  2014年   39241篇
  2013年   51639篇
  2012年   51027篇
  2011年   53635篇
  2010年   39169篇
  2009年   42128篇
  2008年   50352篇
  2007年   51101篇
  2006年   54212篇
  2005年   49821篇
  2004年   46896篇
  2003年   43840篇
  2002年   42375篇
  2001年   77037篇
  2000年   77619篇
  1999年   65027篇
  1998年   20990篇
  1997年   19199篇
  1996年   19331篇
  1995年   18220篇
  1994年   15618篇
  1993年   14367篇
  1992年   47398篇
  1991年   44984篇
  1990年   42669篇
  1989年   40809篇
  1988年   37263篇
  1987年   36264篇
  1986年   33802篇
  1985年   32040篇
  1984年   24414篇
  1983年   20610篇
  1982年   12746篇
  1981年   11222篇
  1979年   20981篇
  1978年   14901篇
  1977年   12472篇
  1976年   11612篇
  1975年   11864篇
  1974年   14198篇
  1973年   13744篇
  1972年   12915篇
  1971年   11669篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
The pattern evoked electroretinogram (PERG) was investigated in 11 patients with unilateral optic nerve disease and in a series of age-matched controls. The visually evoked potential (VEP) was also measured. The PERG showed a similar reduction to the VEP in optic nerve disease. Serial studies indicate that the PERG may not be affected immediately in some instances but may show a gradual decline over several months.  相似文献   
912.
The administration to mice of 1-methyl-4-(2'-methylphenyl)-1,2,3, 6-tetrahydropyridine (2'-CH3-MPTP), a substituted analog of the dopaminergic neurotoxin MPTP caused even more dopaminergic toxicity than MPTP itself. Under conditions in which MPTP was relatively ineffective (i.e. two injections per day of 0.113 mmol/kg at an interval of 6 h for one or two days), 2'-CH3-MPTP caused a very large decrement in the neostriatal content of dopamine and its metabolites and a corresponding decrement in the capacity of a neostriatal synaptosomal preparation to take up [3H]dopamine. Moreover, 2'-CH3-MPTP administration (as few as four injections) caused a virtually complete loss of nerve cells in the zona compacta of the substantia nigra. This compound, like MPTP, may prove to be a valuable research tool.  相似文献   
913.
The aims of this research are to (1) present the French version of the Patient Generated Index (PGI, [17]), (2) test its psychometric characteristics and (3) examine the tool’s practical limitations. To achieve those goals, we conducted two studies. The first was a qualitative study of 18 participants who indicated their difficulties and expressed other comments concerning the completion of an initial back translation of the PGI. The second study tested the psychometric qualities of the adapted and revised back translation of the PGI with 97 cancer patients. To assess criterion validity, they also completed the Quality of Life Questionnaire C30 (QLQ-C30), Profile of Mood States (POMS) and Satisfaction With Life Scale (SWLS). The results indicate that PGI has good sensitivity, validity and test-retest stability. Test-retest reliability, nevertheless, must be improved.  相似文献   
914.
915.
The red eye     
A red eye is a cardinal sign of ocular inflammation. Most cases are benign and can be managed by the primary care provider. The key is recognizing cases requiring ophthalmological consultation by differentiating between ciliary and conjunctival injection. Ciliary injection indicates inflammation of the cornea, iris, or ciliary body, whereas conjunctival injection mainly affects the posterior conjunctival blood vessels. The author has stated that he does not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article. The author also does not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.  相似文献   
916.
IPEX (immunodysregulation, polyendocrinopathy, enteropathy, X linked syndrome) is a rare disorder which usually results in death in early infancy or childhood. Clinical awareness remains the cornerstone of diagnosis, and provided that the diagnosis is entertained, mutation analysis for FOXP3 gene mutations can be confirmatory. Two new patients in whom IPEX was diagnosed retrospectively are reported.  相似文献   
917.
PURPOSE: This study describes the prevalence of probable major depressive disorder (MDD) as well as other depressive disorders (ODD) and severity of depressive symptoms in a national sample of women with spinal cord injury (SCI) and compares them with a case-matched sample of men with SCI. METHODS: A sample of 585 women was drawn and case-matched with men from the SCI Model System National SCI Database according to level/completeness of injury, follow-up year, and age. The outcome measure of depression was the Patient Health Questionnaire. MAIN FINDINGS: Prevalence rates for women were 7.9% for probable MDD and 9.7% for ODD; rates for men were 9.9% and 10.3%, respectively. Logistic regression revealed that women who were divorced or at year 1 follow-up had a higher odds of having probable MDD (odds ratio [OR], 3.4 and 2.9, respectively). Employed women and men had significantly lower odds of probable MDD (OR, 0.274 and 0.358, respectively). Statistically significant differences were not found in gender comparisons for either probable MDD or symptom severity, which also were not associated with injury characteristics. CONCLUSION: The most significant, and unexpected, research finding is the absence of gender differences in probable MDD and symptom severity. Results challenge notions that depression will necessarily follow SCI; that injury characteristics determine the development and severity of depression; and that women experience a greater burden of depression than men. The main clinical implication is that depression screening and referral should be a routine feature of health care for women living with SCI, as well as for their male counterparts. Furthermore, nearly one fourth of women and men reported experiencing some or greater difficulty in daily life and relationships in the absence of probable depressive disorder, warranting monitoring of subsyndromal depression as well.  相似文献   
918.
919.
920.
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