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   194776篇
  免费   2372篇
  国内免费   95篇
耳鼻咽喉   1336篇
儿科学   7145篇
妇产科学   3406篇
基础医学   19613篇
口腔科学   2055篇
临床医学   14265篇
内科学   35015篇
皮肤病学   1180篇
神经病学   18741篇
特种医学   9490篇
外科学   30416篇
综合类   2413篇
一般理论   13篇
预防医学   19755篇
眼科学   3116篇
药学   10690篇
中国医学   701篇
肿瘤学   17893篇
  2024年   27篇
  2023年   190篇
  2022年   344篇
  2021年   702篇
  2020年   475篇
  2019年   668篇
  2018年   22481篇
  2017年   17788篇
  2016年   20032篇
  2015年   1623篇
  2014年   1638篇
  2013年   1815篇
  2012年   8619篇
  2011年   22723篇
  2010年   19701篇
  2009年   12326篇
  2008年   20823篇
  2007年   23015篇
  2006年   1853篇
  2005年   3397篇
  2004年   4509篇
  2003年   5348篇
  2002年   3340篇
  2001年   376篇
  2000年   474篇
  1999年   278篇
  1998年   373篇
  1997年   353篇
  1996年   195篇
  1995年   182篇
  1994年   161篇
  1993年   105篇
  1992年   76篇
  1991年   112篇
  1990年   157篇
  1989年   99篇
  1988年   70篇
  1987年   58篇
  1986年   28篇
  1985年   43篇
  1984年   31篇
  1983年   39篇
  1982年   36篇
  1980年   57篇
  1974年   23篇
  1938年   60篇
  1937年   26篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing.  相似文献   
53.
54.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  相似文献   
55.
Abstract:  The identification of tumor-specific proteins located at the plasma membrane is hampered by numerous methodological pitfalls many of which are associated with the post-translational modification of such proteins. Here, we present a new combination of detergent fractionation of cells and of subtractive suppression hybridization (SSH) to gain overexpressed genes coding for membrane-associated or secreted proteins. Fractionation of subcellular components by digitonin allowed sequestering mRNA of the rough Endoplasmatic reticulum and thereby increasing the percentage of sequences coding for membrane-bound proteins. Fractionated mRNAs from the cutaneous T-cell lymphoma (CTCL) cell line HuT78 and from normal peripheral blood monocytes were used for SSH leading to the enrichment of sequences overexpressed in the tumor cells. We identified some 21 overexpressed genes, among them are GPR137B, FAM62A, NOMO1, HSP90, SLIT1, IBP2, CLIF, IRAK and ARC. mRNA expression was tested for selected genes in CTCL cell lines, skin specimens and peripheral blood samples from CTCL patients and healthy donors. Several of the detected sequences are clearly related to cancer, but have not yet been associated with CTCL. qPCR confirmed an enrichment of these mRNAs in the rough endoplasmic reticulum fraction. RT-PCR confirmed the expression of these genes in skin specimens and peripheral blood of CTCL patients. Western blotting verified protein expression of HSP90 and IBP2 in HuT78. GPR137B could be detected by immunohistology in HuT78 and in keratinocytes of dysplastic epidermis, but also in sweat glands of healthy skin. In summary, we developed a new technique, which allows identifying overexpressed genes coding preferentially for membrane-associated proteins.  相似文献   
56.
57.
58.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
59.
60.
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography (PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant potential of esophageal submucosal tumors.  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