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   1671篇
  免费   110篇
  国内免费   8篇
耳鼻咽喉   19篇
儿科学   106篇
妇产科学   56篇
基础医学   217篇
口腔科学   23篇
临床医学   150篇
内科学   369篇
皮肤病学   43篇
神经病学   75篇
特种医学   58篇
外科学   165篇
综合类   21篇
预防医学   72篇
眼科学   92篇
药学   151篇
中国医学   5篇
肿瘤学   167篇
  2023年   29篇
  2022年   40篇
  2021年   83篇
  2020年   61篇
  2019年   51篇
  2018年   79篇
  2017年   49篇
  2016年   67篇
  2015年   51篇
  2014年   88篇
  2013年   83篇
  2012年   155篇
  2011年   132篇
  2010年   66篇
  2009年   56篇
  2008年   99篇
  2007年   107篇
  2006年   94篇
  2005年   64篇
  2004年   66篇
  2003年   60篇
  2002年   51篇
  2001年   15篇
  2000年   12篇
  1999年   19篇
  1998年   9篇
  1997年   7篇
  1996年   9篇
  1995年   4篇
  1994年   4篇
  1993年   5篇
  1992年   5篇
  1991年   7篇
  1990年   5篇
  1989年   2篇
  1988年   4篇
  1987年   6篇
  1986年   4篇
  1985年   8篇
  1984年   4篇
  1983年   5篇
  1982年   2篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   4篇
  1970年   4篇
  1969年   3篇
  1968年   2篇
  1965年   1篇
排序方式: 共有1789条查询结果,搜索用时 0 毫秒
1.
2.
3.
Sturge-Weber syndrome is a rare neurocutaneous disorder characterized by a facial nevus flammeus and extensive angiomatous changes involving the leptomeninges, the dura, and vessels of the gray and white matter. Oculodermal melanocytosis is characterized by hyperpigmentation of the facial skin in the distribution of the ophthalmic, maxillary, and occasionally mandibular division of the trigeminal nerve.  相似文献   
4.
PurposeNoroviruses are common viral agents in acute diarrhea in all age groups worldwide. Norovirus has been classified into 10 genogroups, GI to GX with over 48 genotypes among them the GII.4 genotype has evolved over time with a clear pattern of periodic variant replacement. Immunity is strain or genotype specific with little or no protection conferred across genogroups. The present study was aimed to determine the epidemiology, prevalent genotypes of norovirus in children below five years of age in the Hyderabad region, India.MethodsThe stool samples and clinical data were collected from 458 children below 5 years of age comprising of cases with acute gastroenteritis (n ?= ?366) and a control group (n ?= ?92) admitted to the pediatric ward. All the samples were tested for Norovirus by ELISA and RT-PCR. Sequencing was done for predominant strains.Results10.3% (n ?= ?38) of cases and 3.2% (n ?= ?3) of the control group were found to be Norovirus positive. Predominant genotypes were GII-82.5% followed by GI-12.5%.ConclusionSequencing and Phylogenetic analyses of 20 GII.4 strains was done. All of the isolates are clustered away from published the GII.4 variants thus suggesting the appearance of a new variant.  相似文献   
5.
6.
Hematological profile of HIV positive patients   总被引:4,自引:0,他引:4  
A series of 500 HIV positive patients referred to our centre for CD4 and CD8 cell enumeration are included in this study. The following parameters were studied in each of these patients: Hb, RBC indicates, WBC count, platelet count, three part differential count, absolute CD4 and CD8 counts. Male:Female ratio of 4.9:1 was noted 30.8% patients has anemia (Hb<10 gm%), with an average Hb value of 8.1 gm%. The anemia was normochromic, normocytic in 61% of patients, microcytic in 33% and macrocytic in 6% patients. The absolute CD4 count was less than 200 ul in 50.2% patients with an average value of 92/ul. Thrombocytopenia was seen in 13% patients with average platelet count 0.92x10(3)/ul.  相似文献   
7.
8.
Mitral regurgitation results from the incomplete closure of the mitral valve, and the noninvasive diagnosis of this disease remains an important clinical goal. In this study, steady flow computer simulations were used to evaluate flow convergence method for flow rate estimation. The hemispheric and hemielliptic formulae were compared for accuracy in the presence of complicating factors such, as ventricular confinement, orifice shape, and aortic outflow. Results showed that in the absence of aortic outflow and ventricular confinement, there was a plateau zone where the hemispheric formula approximated the true flow rate, independent of orifice shape. However, in the presence of complicating factors such as aortic outflow and ventricular confinement, there was no clear zone where the hemispheric formula could be applied. The hemielliptic formula, however, worked in, all cases, regardless of chamber size or magnitude of aortic outflow. Therefore, application of the hemielliptic formula shold be considered in future clinical studies.  相似文献   
9.
10.
Various polymorphisms of the MDR1 gene that encodes for P-glycoprotein (P-gp), a transmembrane pump, have been identified. A silent mutation C3435T in exon 26 and a G2677T mutation in exon 21 have been correlated with P-gp expression and function in humans. The objectives of this study were (a) to determine whether the MDR1 exon 21 and exon 26 polymorphisms were related to steroid weaning in a pediatric heart transplant (HTx) population, and (b) to determine whether an association exist between the MDR1 exon 21 and exon 26 polymorphisms in these patients. Sixty-nine pediatric HTx patients were studied. MDR1 genotyping was determined by polymerase chain reaction amplification, sequencing the DNA, and sequence evaluation using Polyphred software (University of Washington) to identify genotypes. The steroid dose at 1 year post-transplantation was recorded. For steroid weaning at one year post-HTx for MDR1 C3435T, 12 of 18 (67%) patients in the CC genotype were still on prednisone, whereas only 18 of 47 (38%) of the CT/TT group were still receiving prednisone (p = 0.04). Similar results were observed for the MDR1 G2677T genotyping and steroid weaning. Forty-three of 46 patients (93.5%) who have MDR1 C3435T allele also have a mutant G2677T allele (p < 0.001). We conclude that (a) a significantly larger number of MDR1 3435 CC HTx patients remain on steroids at 1 year after transplantation, and (b) the MDR1 C3435T genotype is associated with the G2677 genotype in pediatric HTx patients.  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