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   10463篇
  免费   473篇
  国内免费   46篇
耳鼻咽喉   234篇
儿科学   767篇
妇产科学   452篇
基础医学   1024篇
口腔科学   245篇
临床医学   974篇
内科学   2293篇
皮肤病学   398篇
神经病学   616篇
特种医学   297篇
外国民族医学   1篇
外科学   1411篇
综合类   353篇
一般理论   3篇
预防医学   859篇
眼科学   248篇
药学   544篇
  1篇
中国医学   13篇
肿瘤学   249篇
  2017年   59篇
  2016年   55篇
  2015年   85篇
  2014年   100篇
  2013年   158篇
  2012年   210篇
  2011年   200篇
  2010年   165篇
  2009年   218篇
  2008年   172篇
  2007年   170篇
  2006年   214篇
  2005年   168篇
  2004年   116篇
  2003年   139篇
  2002年   132篇
  2001年   136篇
  2000年   121篇
  1999年   143篇
  1998年   182篇
  1997年   217篇
  1996年   238篇
  1995年   194篇
  1994年   194篇
  1993年   177篇
  1992年   174篇
  1991年   172篇
  1990年   154篇
  1989年   169篇
  1988年   142篇
  1987年   152篇
  1986年   123篇
  1985年   99篇
  1984年   110篇
  1983年   71篇
  1982年   61篇
  1981年   79篇
  1980年   57篇
  1979年   63篇
  1978年   54篇
  1977年   60篇
  1976年   63篇
  1959年   344篇
  1958年   759篇
  1957年   868篇
  1956年   771篇
  1955年   803篇
  1954年   781篇
  1949年   181篇
  1948年   125篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Restriction fragment length polymorphism (RFLP) of human mitochondrial DNA was analysed in a sample of 87 subjects from Apulia (South Italy) by the restriction enzymes Hpa I, Bam HI, Hae II, Msp I, Ava II, and Hinc II using total blood cell DNA probed by human mtDNA from placenta. Five BamHI morphs were observed, two of which are new ( Bam HI-4 and -5), as well as one new Ava II morph ( Ava II-28). The association Bam HI-4/ Ava II-28 enables us to demonstrate for the first time two polymorphic Bam HI sites present together in the same mtDNA molecule. In agreement with historical data the Apulian sample has been shown to be the most heterogeneous Italian population so far tested.  相似文献   
4.
The synthesis of TPH-13 (Glp-Glu-Lys-Pro-Tyr-Trp-Pro-Pro-Pro-Ile-Tyr-Pro-Met-OH), a tridecapeptide isolated from the skin of the South American frog Phyllomedusa rohdei, is described and alternative approaches are discussed.  相似文献   
5.
Intratemporal vascular tumors: detection with CT and MR imaging   总被引:1,自引:0,他引:1  
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion.  相似文献   
6.
7.
Abstract:  In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions.  相似文献   
8.
9.
10.
Epidemiology of borderline personality disorder   总被引:1,自引:0,他引:1  
The limited epidemiological data available on borderline personality disorder suggest that the prevalence of the disorder is between .2 and 1.8 percent in the general community, 15 percent among psychiatric inpatients, and 50 percent among psychiatric inpatients with a diagnosis of personality disorder. No data on the incidence--the rate of new cases--of the disorder have been reported, and inferences about incidence based on prevalence rates are complicated by differences in the formal designation of personality disorders before and after DSM-III was issued. Current findings suggest that about 76 percent of borderline patients are female. Epidemiological study of borderline personality disorder has been hindered by the lack of a brief semistructured interview that can be used with large population samples and that does not require substantial clinical expertise. The authors discuss alternative research methods, including use of lay interviewers, recoding of existing data, telephone interviews, and self-report inventories.  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