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   183541篇
  免费   33290篇
  国内免费   2493篇
耳鼻咽喉   5538篇
儿科学   6223篇
妇产科学   2946篇
基础医学   7295篇
口腔科学   2127篇
临床医学   29706篇
内科学   54850篇
皮肤病学   7940篇
神经病学   17725篇
特种医学   7428篇
外国民族医学   1篇
外科学   45372篇
综合类   683篇
现状与发展   72篇
一般理论   17篇
预防医学   9764篇
眼科学   4079篇
药学   3461篇
  1篇
中国医学   68篇
肿瘤学   14028篇
  2024年   694篇
  2023年   4892篇
  2022年   1388篇
  2021年   3625篇
  2020年   6319篇
  2019年   2708篇
  2018年   8005篇
  2017年   7773篇
  2016年   8887篇
  2015年   8928篇
  2014年   16340篇
  2013年   16925篇
  2012年   7595篇
  2011年   7663篇
  2010年   11517篇
  2009年   15246篇
  2008年   7890篇
  2007年   6357篇
  2006年   8864篇
  2005年   6105篇
  2004年   5322篇
  2003年   4225篇
  2002年   4246篇
  2001年   4005篇
  2000年   3144篇
  1999年   3485篇
  1998年   4074篇
  1997年   3785篇
  1996年   3670篇
  1995年   3502篇
  1994年   2224篇
  1993年   1823篇
  1992年   1567篇
  1991年   1552篇
  1990年   1205篇
  1989年   1310篇
  1988年   1151篇
  1987年   1004篇
  1986年   1010篇
  1985年   872篇
  1984年   805篇
  1983年   745篇
  1982年   836篇
  1981年   671篇
  1980年   605篇
  1979年   416篇
  1978年   486篇
  1977年   547篇
  1976年   376篇
  1975年   382篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
The purpose of this study was to determine the genetic characteristics of foot polydactyly and identify its inheritance pattern by analyzing familial pedigree. Five cases from 2 Korean families were studied: 1 is a family whose members have been affected for 4 generations and the other for 2 generations. Using peripheral blood samples, we performed chromosomal analysis using the banding technique with Giemsa stain and karyotyping. We investigated the shape and structure of 46 chromosomes, looking for translation, deletion, inversion, ring chromosome, and isochromosome abnormalities. All peripheral blood samples demonstrated no chromosomal abnormalities, though the genetic nature of foot polydactyly and a new genetic locus was identified recently by other studies. Familial pedigree analysis suggested that polydactyly was inherited as an autosomal dominant trait in the first family. The mode of inheritance for the second family could not be determined due to an insufficient number of family members. The result of this study brought us to the conclusion that, while genetic factors play a major role in polydactyly, other factors may contribute to its occurrence.  相似文献   
103.
Laparoscopic procedures continue to gain popularity over traditional open procedures for a number of abdominal and pelvic surgeries. With increasing experience, the application of this technique is rising because it provides an alternative, less invasive, approach to various surgical procedures. Herein, we report our experience with adult patients with polycystic kidney disease, requiring bilateral laparoscopic nephrectomy before renal transplantation.  相似文献   
104.
105.
Cerebrospinal fluid (CSF) from 7 patients with infantile spasms (mean age: 6.7 months) was collected before and after treatment with adrenocorticotropic hormone (ACTH). The concentration of neurotransmitter metabolites was analyzed using high-performance liquid chromatography and compared to the metabolite concentration in the CSF from 7 age-matched controls (mean age: 6.1 months). Pretreatment levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid, 3-methoxy-4-hydroxyphenyl glycol (MHPG), and kynurenine were significantly lower in infantile spasm patients compared to controls. Following treatment, marked increases in 5-HIAA and decreases in kynurenine levels were observed in the CSF of the 5 infants whose seizures were eliminated or reduced by ACTH. In the 2 nonresponders 5-HIAA levels decreased. The level of MHPG was reduced slightly in 5 infants, including the 2 nonresponders, and was increased in 2 responders. CSF homovanillic acid levels increased in 4 infantile spasm infants and decreased in 3 following ACTH. These data demonstrate that the presence of seizures in infantile spasms is associated with a significant decrease in serotonergic activity and that elimination of seizures by ACTH is accompanied by increased serotonin turnover. The simultaneous increase of 5-HIAA and decrease of kynurenine, an alternate metabolite of tryptophan, suggests an underlying disturbance of tryptophan metabolism in infantile spasms. The possibility that elimination of seizures by ACTH may be related to decreased production of certain kynurenine metabolites, particularly quinolinic acid, is discussed.  相似文献   
106.
Myelofibrosis with myeloid metaplasia (MMM) is currently classified as a classic (ie, BCR-ABL-negative) myeloproliferative disorder characterized by anemia, multiorgan extramedullary hematopoiesis, constitutional symptoms, and premature death from either leukemic transformation or other disease complications. Stem cell transplantation can be curative, but many patients either are not appropriate candidates or do not choose to accept the significant risks associated with transplantation. Current pharmacologic therapy has been beneficial mainly in terms of palliating disease-associated cytopenias, constitutional symptoms, splenomegaly, and other organ damage from excess myeloproliferation. Novel treatment strategies are under investigation, including targeted inhibition of JAK2V617F, the activating tyrosine kinase point mutation present in about half of patients with MMM. In this article, we review both the old and new pharmacologic options for MMM.  相似文献   
107.
108.
109.
110.
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