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   975篇
  免费   43篇
  国内免费   13篇
耳鼻咽喉   5篇
儿科学   36篇
妇产科学   10篇
基础医学   101篇
口腔科学   36篇
临床医学   95篇
内科学   191篇
皮肤病学   11篇
神经病学   11篇
特种医学   229篇
外科学   140篇
综合类   15篇
预防医学   29篇
眼科学   15篇
药学   63篇
肿瘤学   44篇
  2022年   4篇
  2021年   9篇
  2020年   8篇
  2019年   5篇
  2018年   13篇
  2017年   11篇
  2016年   8篇
  2015年   13篇
  2014年   25篇
  2013年   30篇
  2012年   34篇
  2011年   27篇
  2010年   38篇
  2009年   36篇
  2008年   19篇
  2007年   34篇
  2006年   20篇
  2005年   30篇
  2004年   18篇
  2003年   8篇
  2002年   14篇
  2001年   11篇
  2000年   12篇
  1999年   13篇
  1998年   48篇
  1997年   60篇
  1996年   51篇
  1995年   48篇
  1994年   47篇
  1993年   30篇
  1992年   16篇
  1991年   13篇
  1990年   13篇
  1989年   20篇
  1988年   31篇
  1987年   16篇
  1986年   32篇
  1985年   27篇
  1984年   13篇
  1983年   19篇
  1982年   20篇
  1981年   11篇
  1980年   12篇
  1979年   7篇
  1978年   6篇
  1977年   12篇
  1976年   16篇
  1975年   4篇
  1970年   5篇
  1967年   3篇
排序方式: 共有1031条查询结果,搜索用时 15 毫秒
91.
Neurogenic pulmonary edema   总被引:3,自引:0,他引:3  
Neurogenic pulmonary edema (NPE) is usually defined as an acute pulmonary edema occurring shortly after a central neurologic insult. It has been reported regularly for a long time in numerous and various injuries of the central nervous system in both adults and children, but remains poorly understood because of the complexity of its pathophysiologic mechanisms involving hemodynamic and inflammatory aspects. NPE seems to be under-diagnosed in acute neurologic injuries, partly because the prevention and detection of non-neurologic complications of acute cerebral insults are not at the forefront of the strategy of physicians. The presence of NPE should be high on the list of diagnoses when patients with central neurologic injury suddenly become dyspneic or present with a decreased P(a)o(2)/F(i)o(2) ratio. The associated mortality rate is high, but recovery is usually rapid with early and appropriate management. The treatment of NPE should aim to meet the oxygenation needs without impairing cerebral hemodynamics, to avoid pulmonary worsening and to treat possible associated myocardial dysfunction. During brain death, NPE may worsen myocardial dysfunction, preventing heart harvesting.  相似文献   
92.
Platelets have a central role in the development of arterial thrombosis and subsequent cardiovascular events. An appreciation of this complex process has made antiplatelet therapy the cornerstone of cardiovascular disease management. However, numerous patients will experience a recurrent atherothrombotic vascular event despite adequate antiplatelet therapy. Individual differences in the rate of platelet activation and reactivity markedly influence normal hemostasis and the pathological outcome of thrombosis. Such an individual variability is largely determined by environmental and genetic factors. These are known to either hamper platelets' response to agonists, and thereby mimic the pharmacological modulation of platelet function or mask therapy effect and sensitize platelets. In this article, we reviewed the antiplatelet mechanisms of aspirin and clopidogrel and the possible role of different polymorphisms, which may affect the efficacy of antiplatelet therapy. Heterogeneity in the way patients respond to aspirin and clopidogrel may in part reflect variation in cyclooxygenase (COX)-1, COX-2, glycoprotein (GP) Ib alpha, GP Ia/IIa, GP IIb/IIIa, UGT1A6*2, P2Y1, P2Y12, CYP2C9, CYP3A4 and CYP3A5 genotypes.  相似文献   
93.
94.
95.
The possibility for healthy women to cryopreserve their oocytes in order to counter future infertility has gained momentum in recent years. However, women tend to cryopreserve oocytes at an age that is suboptimal from a clinical point of view--in their late thirties--when both oocyte quantity and quality have already considerably diminished and success rates for eventually establishing a pregnancy are thus limited. This also gives rise to ethical concerns, as the procedure is seen as giving false hope to (reproductively speaking) older women. This study evaluates which measures can be taken to turn social freezing into a procedure that is both clinically and ethically better than the current practice. The main objective of these measures is to convince those women who are most likely to (want to) reproduce at an above-average age to cryopreserve their oocytes at a time when this intervention is still likely to lead to a live birth and to discourage fertility clinics from specifically targeting women who have already surpassed the age at which good results can be expected. The possibility for healthy women to cryopreserve their oocytes in order to counter future infertility has gained momentum in recent years. However, women tend to cryopreserve oocytes at a time that is suboptimal from a clinical point of view - in their late thirties - when both oocyte quantity and quality have already considerably diminished and success rates for eventually establishing a pregnancy are thus limited. This also gives rise to ethical concerns, as the procedure is seen as giving false hope to (reproductively speaking) older women. We evaluate which measures can be taken to turn social freezing into a procedure that is both clinically and ethically better than the current practice and discern three different steps: creating public awareness; offering individualized, age-specific information and counselling; and offering predictive tests such as anti-Müllerian hormone measurements or antral follicle count. The main objective of these measures is to convince those women who are most likely to benefit from social freezing to present themselves before age 35 and to discourage fertility clinics from specifically targeting women who have already surpassed the age at which good results can be expected.  相似文献   
96.
97.
Non-specific markers of inflammation such as C-reactive protein (CRP) are associated statistically with an increased risk of atherosclerosis through mechanisms that have not yet been fully elucidated. We investigated the effects of CRP on several aspects of human monocyte biology, a cell type involved in the initiation and progression of atherosclerosis. Blood monocytes isolated from healthy men and premenopausal women (n = 9/group) were exposed to purified CRP (25 microg/ml) for 12 hours. Changes in gene expression were analyzed using a custom-made array containing oligonucleotide sequences of 250 genes expressed by activated monocytes and confirmed by quantitative PCR. CRP increased significantly the expression of the cytokines interleukin (IL)-1alpha, IL-1beta and IL-6, and the chemokines GRO-alpha, GRO-beta and IL-8. CRP also displayed anti-inflammatory effects through upregulation of liver X receptor (LXR) alpha and activin receptor expression, and down-regulation of alpha 2-macroglobulin expression. Increased LXRalpha mRNA expression in both monocytes and the monocytic cell lineTHP-1 was associated with increased LXRalpha protein expression and nuclear translocation, as well as increased ABCA1 mRNA expression, a target gene of LXRalpha. Western blot analysis revealed CRP-induced nuclear translocation of NF-kappaB and activation of p42/44, MAP and Akt kinases. CRP-induced LXRalpha mRNA expression was inhibited by anti-CD64 (FcgammaRI) antibodies and by p42/44 and PI3 kinase inhibitors. This hypothesis-generating study demonstrates that CRP modulates the expression of genes that contribute to both pro- and anti-inflammatory responses in human monocytes. Among these novel anti-inflammatory effects, we show clearly that CRP activates the LXRalpha pathway.  相似文献   
98.
Subarachnoid haemorrhage (SAH) accounts for 1 to 7% of all strokes. In France, the range of incidence of SAH varies between 3 and 8/100,000 inhabitants. Global mortality lies around 40%, including 70% during the first week. The size of more than 90% of all aneurysms is less than 10 mm. In more than 90% of the patients; SAH is sporadic and a familial screening is warranted only after SAH occurring in 2 first-degree relatives. The main risk factors of SAH are tobacco, arterial hypertension and alcohol abuse. Genetic susceptibility may exist: it could involve several genes, the expression of which would characterize pathophysiological pathways implicated in the disease. This could be identified using genomic technique of microarrays, which could explore all the genome, simply using a sample of peripheral venous blood. For example, in the future, this approach could help to identify patients who are at high risk to develop vasospasm after SAH.  相似文献   
99.
100.
The clinical use of array comparative genomic hybridization in the evaluation of patients with multiple congenital anomalies and/or mental retardation has recently led to the discovery of a number of novel microdeletion and microduplication syndromes. We present four male patients with overlapping molecularly defined de novo microdeletions of 16q24.3. The clinical features observed in these patients include facial dysmorphisms comprising prominent forehead, large ears, smooth philtrum, pointed chin and wide mouth, variable cognitive impairment, autism spectrum disorder, structural anomalies of the brain, seizures and neonatal thrombocytopenia. Although deletions vary in size, the common region of overlap is only 90 kb and comprises two known genes, Ankyrin Repeat Domain 11 (ANKRD11) (MIM 611192) and Zinc Finger 778 (ZNF778), and is located approximately 10 kb distally to Cadherin 15 (CDH15) (MIM 114019). This region is not found as a copy number variation in controls. We propose that these patients represent a novel and distinctive microdeletion syndrome, characterized by autism spectrum disorder, variable cognitive impairment, facial dysmorphisms and brain abnormalities. We suggest that haploinsufficiency of ANKRD11 and/or ZNF778 contribute to this phenotype and speculate that further investigation of non-deletion patients who have features suggestive of this 16q24.3 microdeletion syndrome might uncover other mutations in one or both of these genes.  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