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   5609篇
  免费   384篇
  国内免费   34篇
耳鼻咽喉   41篇
儿科学   164篇
妇产科学   127篇
基础医学   818篇
口腔科学   174篇
临床医学   435篇
内科学   1348篇
皮肤病学   134篇
神经病学   724篇
特种医学   173篇
外科学   509篇
综合类   7篇
一般理论   1篇
预防医学   392篇
眼科学   64篇
药学   400篇
中国医学   15篇
肿瘤学   501篇
  2024年   10篇
  2023年   61篇
  2022年   173篇
  2021年   272篇
  2020年   149篇
  2019年   221篇
  2018年   234篇
  2017年   143篇
  2016年   208篇
  2015年   227篇
  2014年   277篇
  2013年   352篇
  2012年   521篇
  2011年   484篇
  2010年   276篇
  2009年   222篇
  2008年   323篇
  2007年   327篇
  2006年   341篇
  2005年   249篇
  2004年   261篇
  2003年   216篇
  2002年   174篇
  2001年   25篇
  2000年   26篇
  1999年   38篇
  1998年   42篇
  1997年   22篇
  1996年   23篇
  1995年   16篇
  1994年   15篇
  1993年   13篇
  1992年   12篇
  1991年   3篇
  1990年   10篇
  1989年   8篇
  1988年   12篇
  1987年   10篇
  1986年   3篇
  1985年   4篇
  1984年   8篇
  1983年   2篇
  1981年   2篇
  1980年   2篇
  1974年   1篇
  1970年   1篇
  1969年   1篇
  1946年   1篇
  1943年   1篇
  1921年   1篇
排序方式: 共有6027条查询结果,搜索用时 15 毫秒
121.
The nucleoside analogue decitabine can deplete the epigenetic regulator DNA methyltransferase 1 (DNMT1), an effect that occurs, and is saturated at, low concentrations/doses. A reason to pursue this molecular-targeted effect instead of the DNA damage/cytotoxicity produced with high concentrations/doses, is that non-cytotoxic DNMT1-depletion can cytoreduce even p53-null myeloid malignancies while sparing normal haematopoiesis. We thus identified minimum doses of decitabine (0·1–0·2 mg/kg) that deplete DNMT1 without off-target anti-metabolite effects/cytotoxicity, and then administered these well-tolerated doses frequently 1–2X/week to increase S-phase dependent DNMT1-depletion, and used a Myeloid Malignancy Registry to evaluate long-term outcomes in 69 patients treated this way. Consistent with the scientific rationale, treatment was well-tolerated and durable responses were produced (~40%) in genetically heterogeneous disease and the very elderly.  相似文献   
122.
T-cell large granular lymphocytic leukaemia (T-LGLL) is a chronic clonal lymphoproliferative disorder of cytotoxic T lymphocytes which commonly occurs in older patients and is often associated with autoimmune diseases. Among 246 patients with T-LGLL seen at our institution over the last 10 years, we encountered 15 cases following solid organ or haematopoietic stem cell transplantation. Here, we studied the clinical characterization of these cases and compared them to de novo T-LGLL. This experience represented a clear picture of the intricate nature of the disease manifestation and the complexities of several immune mechanisms triggering the clonal expansion.  相似文献   
123.
124.
European Journal of Nuclear Medicine and Molecular Imaging - Cardiac imaging with positron emission tomography/computed tomography (PET/CT) allows measurement of coronary artery calcium (CAC),...  相似文献   
125.
126.

Purpose

This study aims to identify whether selected patient and ward-related factors are associated with the use of coercive measures. Data were collected as part of the EUNOMIA international collaborative study on the use of coercive measures in ten European countries.

Methods

Involuntarily admitted patients (N = 2,027) were divided into two groups. The first group (N = 770) included patients that had been subject to at least one of these coercive measures during hospitalization: restraint, and/or seclusion, and/or forced medication; the other group (N = 1,257) included patients who had not received any coercive measure during hospitalization. To identify predictors of use of coercive measures, both patients’ sociodemographic and clinical characteristics and centre-related characteristics were tested in a multivariate logistic regression model, controlled for countries’ effect.

Results

The frequency of the use of coercive measures varied significantly across countries, being higher in Poland, Italy and Greece. Patients who received coercive measures were more frequently male and with a diagnosis of psychotic disorder (F20–F29). According to the regression model, patients with higher levels of psychotic and hostility symptoms, and of perceived coercion had a higher risk to be coerced at admission. Controlling for countries’ effect, the risk of being coerced was higher in Poland. Patients’ sociodemographic characteristics and ward-related factors were not identifying as possible predictors because they did not enter the model.

Conclusions

The use of coercive measures varied significantly in the participating countries. Clinical factors, such as high levels of psychotic symptoms and high levels of perceived coercion at admission were associated with the use of coercive measures, when controlling for countries’ effect. These factors should be taken into consideration by programs aimed at reducing the use of coercive measures in psychiatric wards.  相似文献   
127.
Adult patients with Niemann-Pick disease type C (NPC) usually develop cognitive impairment progressing to dementia, whose pathophysiology remains still unclear. Noteworthy parallels exist in cognitive impairment and cellular pathology of NPC and Alzheimer’s disease (AD). In particular, alterations of cholinergic system, which represent one of the pathological hallmarks and contribute to cognitive deterioration in AD, have recently been demonstrated in a human brain autopsy and in an experimental model of NPC. This finding raised the issue that central cholinergic circuits dysfunction may contribute to pathophysiology of cognitive impairment in NPC as well, and prompted us to evaluate the cholinergic functional involvement in NPC patients by applying a neurophysiologic technique, named short-latency afferent inhibition (SAI). We describe clinical, biochemical, molecular and neuropsychological features, and SAI findings in three patients affected by NPC. Diagnosis of NPC was assessed by molecular analysis of the NPC1 gene in all patients. In two of them, biochemical analysis of intracellular accumulation of unesterified cholesterol was also performed. The main clinical features were cerebellar ataxia, vertical supranuclear gaze palsy and a variable degree of cognitive impairment ranging from only memory impairment to severe dementia. Electrophysiological evaluation revealed a reduced SAI in all three patients. Our SAI findings provide evidence of cholinergic dysfunction in patients with the adult form of NPC, supporting that cholinergic alterations may play a role in cognitive impairment in NPC, and strengthening the similarities between NPC and AD.  相似文献   
128.
129.
Juvenile dermatomyositis is an immune-mediated inflammatory multi-system disease involving mainly striated muscles and skin. Typical dermatological features are fundamental to establish the diagnosis, especially whenever the myopathy is very mild or absent, as it occurs in the form called as amyopathic juvenile dermatomyositis. Sometimes, systemic rheumatic diseases can develop a hyperferritinemia syndrome characterized by hemophagocytosis, namely macrophage activation syndrome, which represents a severe and life-threatening complication. Here, we describe a complex clinical history characterized by a hyper-ferritinemia syndrome after infectious mononucleosis, leading to recurrent episodes of macrophage activation syndrome. Finally, the late onset of several skin changes brought to a diagnosis of amyopathic juvenile dermatomyositis.  相似文献   
130.
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