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   173860篇
  免费   32445篇
  国内免费   2553篇
耳鼻咽喉   5432篇
儿科学   6100篇
妇产科学   3095篇
基础医学   5386篇
口腔科学   2279篇
临床医学   28505篇
内科学   52130篇
皮肤病学   7887篇
神经病学   15738篇
特种医学   7101篇
外国民族医学   9篇
外科学   45044篇
综合类   956篇
现状与发展   73篇
一般理论   21篇
预防医学   8670篇
眼科学   4074篇
药学   3082篇
中国医学   169篇
肿瘤学   13107篇
  2024年   692篇
  2023年   5072篇
  2022年   2189篇
  2021年   4452篇
  2020年   6673篇
  2019年   3065篇
  2018年   8558篇
  2017年   8026篇
  2016年   9116篇
  2015年   9194篇
  2014年   16487篇
  2013年   16844篇
  2012年   7230篇
  2011年   7251篇
  2010年   11250篇
  2009年   14964篇
  2008年   6866篇
  2007年   5190篇
  2006年   7501篇
  2005年   4655篇
  2004年   3867篇
  2003年   2689篇
  2002年   2721篇
  2001年   4115篇
  2000年   3317篇
  1999年   3485篇
  1998年   3786篇
  1997年   3561篇
  1996年   3450篇
  1995年   3307篇
  1994年   2008篇
  1993年   1611篇
  1992年   1506篇
  1991年   1523篇
  1990年   1166篇
  1989年   1284篇
  1988年   1106篇
  1987年   945篇
  1986年   984篇
  1985年   801篇
  1984年   619篇
  1983年   614篇
  1982年   551篇
  1981年   446篇
  1980年   393篇
  1979年   391篇
  1978年   379篇
  1977年   451篇
  1975年   322篇
  1972年   331篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Polycythemia vera is a myeloproliferative disease, which, if untreated, leads to thrombohemorrhagic complications and eventually to progressive myelofibrosis, anemia, and splenomegaly. Two newly available drugs, interferon alfa and imatinib mesylate, may alter the course of this disease. Used as single agents, each produces lasting remissions in about 75% of patients with polycythemia vera. Of significance, change in JAK2 expression has been reported after treatment with both agents.  相似文献   
102.
103.
104.
105.
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   
106.
107.
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   
108.
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   
109.
Xanthogranulomatous orchitis is an extremely rare inflammatory non-neoplastic destructive lesion of the testis. We report a 44-year-old man who presented with right scrotal swelling and two discharging sinuses. Testicular tumor markers were normal. Scrotal ultrasound showed heterogeneous testicular areas and irregular margin of the tunica. Surgical exploration revealed infected, unhealthy testicular tissue with necrosis and tumor-like lesion. Orchidectomy was done and histopathology showed xanthogranulomatous orchitis.  相似文献   
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