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   939805篇
  免费   66777篇
  国内免费   1387篇
耳鼻咽喉   13037篇
儿科学   24507篇
妇产科学   23315篇
基础医学   134124篇
口腔科学   28387篇
临床医学   81061篇
内科学   185210篇
皮肤病学   19390篇
神经病学   72759篇
特种医学   37088篇
外国民族医学   79篇
外科学   153334篇
综合类   18076篇
现状与发展   1篇
一般理论   234篇
预防医学   62031篇
眼科学   21492篇
药学   73037篇
  4篇
中国医学   2177篇
肿瘤学   58626篇
  2018年   9143篇
  2017年   7165篇
  2016年   7933篇
  2015年   9046篇
  2014年   12183篇
  2013年   17742篇
  2012年   24491篇
  2011年   25504篇
  2010年   15036篇
  2009年   14491篇
  2008年   24993篇
  2007年   26110篇
  2006年   26904篇
  2005年   25818篇
  2004年   24937篇
  2003年   23995篇
  2002年   23552篇
  2001年   54925篇
  2000年   56738篇
  1999年   47127篇
  1998年   10856篇
  1997年   9554篇
  1996年   9696篇
  1995年   9017篇
  1994年   8361篇
  1993年   7668篇
  1992年   35597篇
  1991年   34026篇
  1990年   32846篇
  1989年   31973篇
  1988年   29084篇
  1987年   28328篇
  1986年   26368篇
  1985年   25214篇
  1984年   17888篇
  1983年   15190篇
  1982年   7828篇
  1981年   6800篇
  1979年   15842篇
  1978年   10636篇
  1977年   9098篇
  1976年   7893篇
  1975年   8662篇
  1974年   10500篇
  1973年   9893篇
  1972年   9387篇
  1971年   8885篇
  1970年   8455篇
  1969年   7955篇
  1968年   7234篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Uniparental isodisomy (iUPD) is a rare genetic condition caused by non-disjunction during meiosis that ultimately leads to a duplication of either the maternal or paternal chromosome in the affected individual. Two types of disorders can result, those due to imprinted genes and those due to homozygosity of recessive disease-causing mutations. Here, we describe the third known case of complete chromosome 4 iUPD of maternal origin. This condition became apparent during whole genome linkage studies of psychiatric disorders in the Portuguese population. The proband is an adult female with normal fertility and no major medical complaints, but a history of major depressive disorder and multiple suicide attempts. The proband's siblings and parents had normal chromosome 4 genotypes and no history of mood disturbance. A brief review of other studies lends support for the possibility that genes on chromosome 4 might confer risk for mood disorders. We conclude that chromosome 4 maternal uniparental disomy (UPD) is a rare disorder that may present with a major depressive phenotype. The lack of a common disease phenotype between this and two other cases of chromosome 4 iUPD [Lindenbaum et al. [1991] Am J Med Genet 49(Suppl 285):1582; Spena et al. [2004] Eur J Hum Genet 12:891-898) would suggest that there is no vital maternal gene imprinting on chromosome 4. However, since there is no reported case of paternal chromosome 4 UPD, paternal gene imprinting on chromosome 4 cannot be excluded.  相似文献   
72.
In order to assess the state and pathology of the woman's pelvis minor, a number of methods are commonly used among practitioners, encompassing clinical exploration, radiology, MRN, urodynamics, endoscopy and echography.

Echography has been poorly used in clinical pelvic exploration and its reliability is actually a matter of controversy 1. However, echographic surveys can provide us with valuable gynecological data on the state and pathologies of the soft pelvis, within the genital regions or even going beyond them, i.e. the rectal channel, bladder, urethra, anus, vascular plexuses, and all of their supporting tissues.

At our research unit, we have been employing Transvaginal Ultrasound echography (TVU) for a long time in conjunction with other pelvis-focused methods in order to study different kinds of pelvic alterations. TVU has proven to be friendly to use, fast, harmless and inexpensive, allowing serial explorations and producing high-quality dynamic images (loop-cinema, video-tape). Furthermore, this method is fairly aseptic in that the occurrence of faeces in the rectal ampolla is not a nuisance but a bonus in tracking the contours of the rectum walls and other topographical features which would be otherwise difficult to survey.

A complete pelvic floor TVU may add no longer than 5-8 minutes to a routine gynecological examination, can be implemented by the general gynecologist and generates data that can be further studied by the appropriate specialist for a more insightful evaluation 2.  相似文献   
73.
74.
75.
76.
77.
78.
Ten years experience with acute peritoneal dialysis in 39 preterm-, newborn and small infants shows advantage and low risk of surgically implanted single dacron cuffed silicone catheters compared to trocar catheters.  相似文献   
79.
Computed tomography (CT) is currently the imaging modality of choice for assessing the morphology of the adrenal glands in adult patients. Much useful information can be gained using CT in disease processes which primarily involve one or both of the adrenal glands, such as adenomas, as well as in entities which secondarily affect the adrenals, such as pituitary or metastatic disease. The size and configuration of the glands can be readily determined, and masses may be detected. We discuss CT of normal and abnormal adrenal glands with sonographic (US) and pathological correlation, when available. Entities which may mimic adrenal abnormalities are emphasized. Relative advantages of US over CT in the pediatric patient are discussed.  相似文献   
80.
The Dundee Memory Clinic was established in 1991. This paper reviews the diagnosis of the first 150 attenders and compares the findings with those of other memory clinics.  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