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   9628篇
  免费   572篇
  国内免费   262篇
耳鼻咽喉   87篇
儿科学   609篇
妇产科学   518篇
基础医学   4021篇
口腔科学   171篇
临床医学   491篇
内科学   932篇
皮肤病学   83篇
神经病学   319篇
特种医学   365篇
外科学   583篇
综合类   897篇
现状与发展   1篇
预防医学   299篇
眼科学   82篇
药学   265篇
中国医学   53篇
肿瘤学   686篇
  2024年   8篇
  2023年   83篇
  2022年   112篇
  2021年   162篇
  2020年   214篇
  2019年   198篇
  2018年   191篇
  2017年   193篇
  2016年   224篇
  2015年   257篇
  2014年   364篇
  2013年   454篇
  2012年   284篇
  2011年   394篇
  2010年   340篇
  2009年   351篇
  2008年   377篇
  2007年   384篇
  2006年   398篇
  2005年   339篇
  2004年   352篇
  2003年   290篇
  2002年   315篇
  2001年   310篇
  2000年   276篇
  1999年   296篇
  1998年   267篇
  1997年   320篇
  1996年   311篇
  1995年   317篇
  1994年   208篇
  1993年   241篇
  1992年   223篇
  1991年   163篇
  1990年   137篇
  1989年   100篇
  1988年   116篇
  1987年   102篇
  1986年   109篇
  1985年   84篇
  1984年   95篇
  1983年   75篇
  1982年   84篇
  1981年   80篇
  1980年   83篇
  1979年   68篇
  1978年   38篇
  1977年   31篇
  1976年   16篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic.  相似文献   
3.
Sex chromosome trisomies (SCT) are among the most common chromosomal duplications in humans. Due to recent technological advances in non-invasive screening, SCT can already be detected during pregnancy. This calls for more knowledge about the development of (young) children with SCT. This review focused on neurocognitive functioning of children with SCT between 0 and 18 years, on domains of global intellectual functioning, language, executive functioning, and social cognition, in order to identify targets that could benefit from early treatment. Online databases were used to identify peer-reviewed scientific articles using specific search terms. In total 18 studies were included. When applicable, effect sizes were calculated to indicate clinical significance. Results of the reviewed studies show that although traditionally, the focus has been on language and intelligence (IQ) in this population, recent studies suggest that executive functioning and social cognition may also be significantly affected already in childhood. These findings suggest that neuropsychological screening of children diagnosed with SCT should be extended, to also include executive functioning and social cognition. Knowledge about these neurocognitive risks is important to improve clinical care and help identify targets for early support and intervention programs to accommodate for the needs of individuals with SCT.  相似文献   
4.
《Cancer cell》2020,37(1):123-134.e5
  1. Download : Download high-res image (200KB)
  2. Download : Download full-size image
  相似文献   
5.
6.
7.
8.
Cytogenetic abnormalities are observed in approximately two‐thirds of patients with acute myeloid leukemia (AML). Chromosome rearrangements are associated with specific subtypes of AML and associated prognosis. We report a patient with AML, M2, who was primarily refractory to standard induction chemotherapy with idarubicin and cytarabine. Flow cytometry of a bone marrow aspirate showed aberrant expression of B‐cell markers including CD19. Cytogenetic studies disclosed a translocation between 5q35 and 11q13. Fluorescence in situ hybridization analyses demonstrated that neither the NSD1 nor MLL genes were involved in this case. Further study is required to define conclusively the genes involved and their contribution to pathogenesis in this case.  相似文献   
9.
10.
The study analyzes tumor material and normal tissue from 27 patients with pure squamous cell carcinoma of the uterine cervix for loss of heterozygosity (LOH) and microsatellite instability (MSI) on 14 autosomal and 11 X chromosomal loci. Overall, 4-40% of the informative cases showed LOH at autosomal regions with the highest frequency at 3p (21-40%) and a marked frequency at 2q35-q37.1 (12.5%) and 17p13.3 (10%), representing regions with putative tumor suppressor gene (TSG) function. The frequency of X chromosomal LOH ranged from 4% to 20%, with a maximum at Xq28 (20%) and Xq11.2-q12 (17%), again indicating alterations in TSG. A 12% LOH was seen at Xq21.33-q22.3, a region encoding a protein with a regulatory function in the cell cycle via cyclin-dependent kinases. MSI was detected in autosomal regions in up to 7% in regions linked to the X chromosome in up to 11%, probably indicating alterations of mismatch repair mechanisms. Our results and those obtained from the literature suggest that autosomal LOH and MSI in carcinomas of the cervix uteri are predominantly found at regions with putative TSG function. Beside TSG alterations, X chromosomal LOH is probably more strongly connected to disturbances in cell cycle regulation.  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