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   2247篇
  免费   77篇
  国内免费   49篇
耳鼻咽喉   6篇
儿科学   31篇
妇产科学   40篇
基础医学   293篇
口腔科学   24篇
临床医学   227篇
内科学   556篇
皮肤病学   43篇
神经病学   183篇
特种医学   55篇
外科学   487篇
综合类   9篇
预防医学   69篇
眼科学   24篇
药学   109篇
中国医学   2篇
肿瘤学   215篇
  2023年   7篇
  2022年   19篇
  2021年   30篇
  2020年   12篇
  2019年   14篇
  2018年   35篇
  2017年   17篇
  2016年   23篇
  2015年   30篇
  2014年   41篇
  2013年   78篇
  2012年   150篇
  2011年   151篇
  2010年   99篇
  2009年   105篇
  2008年   179篇
  2007年   210篇
  2006年   167篇
  2005年   166篇
  2004年   176篇
  2003年   156篇
  2002年   140篇
  2001年   24篇
  2000年   15篇
  1999年   19篇
  1998年   44篇
  1997年   44篇
  1996年   22篇
  1995年   21篇
  1994年   26篇
  1993年   17篇
  1992年   9篇
  1991年   14篇
  1990年   11篇
  1989年   9篇
  1988年   9篇
  1987年   4篇
  1986年   3篇
  1985年   6篇
  1984年   7篇
  1983年   6篇
  1982年   9篇
  1981年   11篇
  1980年   5篇
  1979年   7篇
  1978年   5篇
  1977年   6篇
  1975年   6篇
  1974年   2篇
  1962年   1篇
排序方式: 共有2373条查询结果,搜索用时 15 毫秒
61.
Essential thrombocythemia, a myeloproliferative neoplasm, is associated with increased platelet count and risk of thrombosis or hemorrhage. Cytoreductive therapy aims to normalize platelet counts despite there being only a minimal association between platelet count and complication rates. Evidence is increasing for a correlation between WBC count and thrombosis, but prospective data are lacking. In the present study, we investigated the relationship between vascular complications and 21 887 longitudinal blood counts in a prospective, multicenter cohort of 776 essential thrombocythemia patients. After correction for confounding variables, no association was seen between blood counts at diagnosis and future complications. However, platelet count outside of the normal range during follow-up was associated with an immediate risk of major hemorrhage (P = .0005) but not thrombosis (P = .7). Elevated WBC count during follow-up was correlated with thrombosis (P = .05) and major hemorrhage (P = .01). These data imply that the aim of cytoreduction in essential thrombocythemia should be to keep the platelet count, and arguably the WBC count, within the normal range. This study is registered at the International Standard Randomized Controlled Trials Number Registry (www.isrctn.org) as number 72251782.  相似文献   
62.
63.
Immediately after the annual scientific meeting of the American Society of Hematology (ASH), a select group of clinical and laboratory investigators in myeloproliferative neoplasms (MPN) is summoned to a post-ASH conference on chronic myeloid leukemia and the BCR-ABL1-negative MPN. The 6th such meeting occurred on December 13–14,2011, in La Jolla, California, USA, under the direction of its founder,Dr. Tariq Mughal. The current document is the first of two reports on this post-ASH event and summarizes the most recent preclinical and clinical advances in polycythemia vera, essential thrombocythemia,and primary myelofibrosis.  相似文献   
64.
During the last several years, research has produced a significant amount of knowledge concerning the characteristics of human γδ T lymphocytes. Findings regarding the immune functions of these cells, particularly their natural killer cell-like lytic activity against tumor cells, have raised expectations for the therapeutic applications of these cells for cancer. Pharmaceutical companies have produced selective agonists for these lymphocytes, and several teams have launched clinical trials of γδ T cell-based cancer therapies. The findings from these studies include hematological malignancies (follicular lymphoma, multiple myeloma, acute and chronic myeloid leukemia), as well as solid tumors (renal cell, breast and prostate carcinomas), consisting of samples from more than 250 patients from Europe, Japan and the United States. The results of these pioneering studies are now available, and this short review summarizes the lessons learned and the role of γδ T cell-based strategies in the current landscape of cancer immunotherapies.  相似文献   
65.
66.
The effect of nonsteroidal antiinflammatory drugs (NSAIDs) on the risk of cardiovascular events remains controversial. Among NSAIDs, only low-dose aspirin exerts protective vascular effects. Low-dose aspirin has been proven effective for secondary prevention. For primary prevention, the usefulness of low-dose aspirin is debated, as illustrated by the differences in recommendations across countries. NSAIDs other than aspirin, whether COX-2 selective or nonselective, increase the risk of cardiovascular events. Among them, naproxen is associated with the smallest risk increase. In patients with a history of coronary artery disease, diclofenac seems to carry the greatest risk, but all NSAIDs should be avoided. Uncertainties persist about aspirin interactions with other NSAIDs and with proton pump inhibitors. An adverse effect of acetaminophen on the risk of cardiovascular disease cannot be completely ruled out.  相似文献   
67.
68.
69.
Here, we analyze the complete coding sequences of all recognized tick-borne flavivirus species, including Gadgets Gully, Royal Farm and Karshi virus, seabird-associated flaviviruses, Kadam virus and previously uncharacterized isolates of Kyasanur Forest disease virus and Omsk hemorrhagic fever virus. Significant taxonomic improvements are proposed, e.g. the identification of three major groups (mammalian, seabird and Kadam tick-borne flavivirus groups), the creation of a new species (Karshi virus) and the assignment of Tick-borne encephalitis and Louping ill viruses to a unique species (Tick-borne encephalitis virus) including four viral types (i.e. Western Tick-borne encephalitis virus, Eastern Tick-borne encephalitis virus, Turkish sheep Tick-borne encephalitis virus and Louping ill Tick-borne encephalitis virus). The analyses also suggest a complex relationship between viruses infecting birds and those infecting mammals. Ticks that feed on both categories of vertebrates may constitute the evolutionary bridge between the three distinct identified lineages.  相似文献   
70.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive death of cortical and spinal motor neurons, for which there is no effective treatment. Using a cell-based assay for compounds capable of preventing motor neuron cell death in vitro, a collection of approximately 40,000 low-molecular-weight compounds was screened to identify potential small-molecule therapeutics. We report the identification of cholest-4-en-3-one, oxime (TRO19622) as a potential drug candidate for the treatment of ALS. In vitro, TRO19622 promoted motor neuron survival in the absence of trophic support in a dose-dependent manner. In vivo, TRO19622 rescued motor neurons from axotomy-induced cell death in neonatal rats and promoted nerve regeneration following sciatic nerve crush in mice. In SOD1(G93A) transgenic mice, a model of familial ALS, TRO19622 treatment improved motor performance, delayed the onset of the clinical disease, and extended survival. TRO19622 bound directly to two components of the mitochondrial permeability transition pore: the voltage-dependent anion channel and the translocator protein 18 kDa (or peripheral benzodiazepine receptor), suggesting a potential mechanism for its neuroprotective activity. TRO19622 may have therapeutic potential for ALS and other motor neuron and neurodegenerative diseases.  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