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   6308篇
  免费   455篇
  国内免费   67篇
耳鼻咽喉   42篇
儿科学   149篇
妇产科学   215篇
基础医学   770篇
口腔科学   89篇
临床医学   537篇
内科学   1686篇
皮肤病学   130篇
神经病学   767篇
特种医学   191篇
外科学   671篇
综合类   11篇
一般理论   3篇
预防医学   335篇
眼科学   72篇
药学   469篇
中国医学   13篇
肿瘤学   680篇
  2024年   19篇
  2023年   147篇
  2022年   299篇
  2021年   474篇
  2020年   277篇
  2019年   299篇
  2018年   350篇
  2017年   221篇
  2016年   269篇
  2015年   298篇
  2014年   311篇
  2013年   363篇
  2012年   503篇
  2011年   463篇
  2010年   240篇
  2009年   191篇
  2008年   303篇
  2007年   333篇
  2006年   283篇
  2005年   263篇
  2004年   229篇
  2003年   209篇
  2002年   175篇
  2001年   36篇
  2000年   24篇
  1999年   35篇
  1998年   31篇
  1997年   17篇
  1996年   22篇
  1995年   19篇
  1994年   18篇
  1993年   17篇
  1992年   9篇
  1991年   14篇
  1990年   10篇
  1989年   8篇
  1988年   9篇
  1987年   5篇
  1986年   4篇
  1984年   4篇
  1983年   3篇
  1982年   3篇
  1981年   4篇
  1979年   4篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
排序方式: 共有6830条查询结果,搜索用时 15 毫秒
991.
A considerable minority of patients with ANCA-associated small-vessel vasculitis are refractory to conventional therapy or experience dose-limiting side effects. Novel therapeutic approaches include rituximab, a genetically engineered chimeric murine-human monoclonal antibody that binds to CD20, which is expressed on human B cells. It was approved in 1997 for the treatment of CD20-positive B-cell non-Hodgkin lymphoma and in 2006 for the treatment of rheumatoid arthritis. The multiple mechanisms proposed for rituximab-mediated B-cell depletion are discussed in this paper. Cumulative data from several open studies on the treatment of microscopic ANCA-associated polyangiitis suggest that in the vast majority of cases rituximab has a beneficial effect. Two randomized controlled trials confirmed these promising results, suggesting that rituximab might be considered as an option for first-line therapy of induction of remission of ANCA-associated vasculitis, and providing an additional tool for treating patients with disease relapse after previous therapy. While rituximab is very effective in the depletion of B cells, current research suggests it could also influence other immune system cells and reestablish immune homeostasis and tolerance. The safety profile of rituximab reveals that most reactions are infusion-related and that the incidence of serious side effects is low. Systemic infection remains a major concern and may result in death. A small number of cases of progressive multifocal leukoencephalopathy reported in patients receiving rituximab in off-label use (albeit none with ANCA-associated vasculitis) highlights the importance of pharmacovigilance.  相似文献   
992.
993.
994.
995.
Semantic dementia (SD) is a neurodegenerative disease belonging to the spectrum of frontotemporal dementia that presents with loss of memory for words and prevalent left temporal pole atrophy. Behavioral disorders, particularly obsessive-compulsive symptoms, are frequent during the course of the disease. We describe a patient presenting with late-onset typical obsessive-compulsive disorder (OCD) that lasted for 10 years as an isolated condition before developing clinical and neuroimaging features of SD. This case alerts clinicians that late-onset OCD may be a psychiatric presentation of a neurodegenerative disorder such as frontotemporal dementia and requires an accurate diagnostic work-up.  相似文献   
996.
997.
Capecitabine plus oxaliplatin combination (XELOX) is the first-line treatment in metastatic colorectal cancer. Here we report a case of acute, severe but substantially reversible, neuromuscular and cardiac toxicity following XELOX chemotherapy. Muscle biopsy findings were consistent with a toxic myopathy with necrotizing features and vacuolar changes; COX-negative fibers were also present. The time course could support a main role for capecitabine, which may have some neurotoxic effects (more frequently central), but a detrimental interaction between the two drugs cannot be ruled out and further studies are needed.  相似文献   
998.
Directed cell migration and axonal guidance are essential steps in neural development that share many molecular mechanisms. The guidance of developing axons and migrating neurons is likely to depend on the precise control of plasmalemma turnover in selected regions of leading edges and growth cones, respectively. Previous results provided evidence of a signaling mechanism that couples chemotropic deleted in colorectal cancer (DCC)/Netrin‐1 axonal guidance and exocytosis through Syntaxin1(Sytx1)/TI‐VAMP SNARE proteins. Here we studied whether Netrin‐1‐dependent neuronal migration relies on a similar SNARE mechanism. We show that migrating neurons in the lower rhombic lip (LRL) express several SNARE proteins, and that DCC co‐associates with Sytx1 and TI‐VAMP in these cells. We also demonstrate that cleavage of Sytx1 by botulinum toxin C1 (BoNT/C1) abolishes Netrin‐1‐dependent chemoattraction of migrating neurons, and that interference of Sytx1 functions with shRNAs or Sytx1‐dominant negatives disrupts Netrin‐1‐dependent chemoattraction of LRL neurons. These findings indicate that a Sytx1/DCC interaction is required for Netrin‐1 guidance of migrating neurons, thereby highlighting a relationship between guidance signaling and SNARE proteins that regulate membrane turnover.  相似文献   
999.
Drug addiction represents a major social problem where addicts and alcoholics continue to seek and take drugs despite adverse social, personal, emotional, and legal consequences. A number of pharmacological compounds have been tested in human addicts with the goal of reducing the level or frequency of intake, but these pharmacotherapies have often been of only moderate efficacy or act in a sub-population of humans. Thus, there is a tremendous need for new therapeutic interventions to treat addiction. Here, we review recent interesting studies focusing on gamma-aminobutyric acid receptors, voltage-gated ion channels, and transcranial magnetic stimulation. Some of these treatments show considerable promise to reduce addictive behaviors, or the early clinical studies or pre-clinical rationale suggest that a promising avenue could be developed. Thus, it is likely that within a decade or so, we could have important new and effective treatments to achieve the goal of reducing the burden of human addiction and alcoholism.  相似文献   
1000.
ObjectiveWe aimed to investigate the relationship between the presence and severity of depression and the degree of motor and functional disability in Parkinson's disease (PD).MethodsOne hundred twenty-two outpatients with PD were enrolled in a neurology department: 65 satisfied the Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition criteria for major depression, and 57 did not (PD-C). Depressive symptoms were assessed by means of the Hamilton Rating Scale for Depression (HRSD), and the PD severity was assessed according to the Hoehn and Yahr System. Activities of daily living and motor symptoms were measured by the Unified PD Rating Scale (UPDRS), parts II and III.ResultsTwenty-nine patients had a mild depression (HRSD total score ranging between 8 and 17), 30 had a moderate depression (HRSD total score ranging between 18 and 24), and 6 had a severe depression (HRSD total score, ≥25). By comparing the 3 groups of patients, it emerged that those with a severe depression showed significantly higher scores at the UPDRS II, UPDRS III, and HY scales than did PD-C or patients with a mild depression. Moreover, patients with a moderate depression scored significantly higher on the UPDRS II, UPDRS III, and HY scales than did PD-C or those with a mild depression.ConclusionsOur findings suggest that depression and motor symptoms/well-being are highly intertwined in patients with PD.  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