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   1961篇
  免费   106篇
  国内免费   19篇
耳鼻咽喉   22篇
儿科学   88篇
妇产科学   8篇
基础医学   242篇
口腔科学   44篇
临床医学   125篇
内科学   522篇
皮肤病学   123篇
神经病学   133篇
特种医学   55篇
外科学   291篇
综合类   5篇
预防医学   69篇
眼科学   40篇
药学   119篇
中国医学   2篇
肿瘤学   198篇
  2023年   20篇
  2022年   58篇
  2021年   69篇
  2020年   39篇
  2019年   43篇
  2018年   54篇
  2017年   43篇
  2016年   45篇
  2015年   52篇
  2014年   74篇
  2013年   91篇
  2012年   139篇
  2011年   160篇
  2010年   78篇
  2009年   64篇
  2008年   125篇
  2007年   106篇
  2006年   133篇
  2005年   93篇
  2004年   100篇
  2003年   71篇
  2002年   92篇
  2001年   43篇
  2000年   31篇
  1999年   14篇
  1998年   18篇
  1997年   13篇
  1996年   20篇
  1995年   12篇
  1994年   15篇
  1993年   17篇
  1992年   10篇
  1991年   7篇
  1990年   12篇
  1989年   9篇
  1988年   7篇
  1987年   8篇
  1986年   5篇
  1985年   8篇
  1984年   5篇
  1983年   5篇
  1980年   8篇
  1979年   8篇
  1977年   7篇
  1972年   4篇
  1971年   6篇
  1970年   6篇
  1968年   4篇
  1967年   4篇
  1966年   5篇
排序方式: 共有2086条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
26.
Neurological complications during the treatment of hematological malignancies have a wide range of causes. Treatment-related leukoencephalopathy has been recognized as a major complication of combined chemotherapy and radiotherapy for central nervous system (CNS) lymphoma, and can complicate the diagnosis of CNS infection. Herein, we present a patient with diffuse large B-cell lymphoma who developed herpes simplex encephalitis (HSE) and subsequent cytomegalovirus encephalitis after chemoradiotherapy for CNS relapse. Although cerebrospinal fluid examination (CSF) showed no significant pleocytosis, brain magnetic resonance imaging and polymerase chain reaction analysis of the CSF were useful in the diagnosis. With a review of the literature on the association between HSE and radiotherapy for CNS malignancies, our case suggests that an awareness of viral encephalitis is important in the differential diagnosis of acute neurologic disturbance during chemoradiotherapy for CNS lymphoma.  相似文献   
27.
Pyoderma gangrenosum is an intractable skin disorder characterized by the development of erythematous pustules or nodules that rapidly progress to destructive, necrotizing, non-infective ulcers. We assessed the efficacy of granulocyte and monocyte adsorption apheresis (GCAP) therapy in two new patients, a 67-year-old man with ulcerations on his lower leg, and a 44-year-old man with turgid erythematous lesions with burrowing abscesses and sinus formation on his hip, groin, and thighs. Both patients received 10 GCAP treatments at 5-day intervals. Their skin lesions responded well. The 9 cmx6 cm ulcer on the lower right leg of the 67-year-old patient was completely covered by regenerated skin at the completion of therapy. The turgid skin lesions containing pustules and ulcers of the other patient showed amelioration and a marked decrease in the volume of exudate. Our results suggest that GCAP is a useful treatment modality for pyoderma gangrenosum.  相似文献   
28.
29.
Leber congenital amaurosis (LCA) is a severe autosomal‐recessive retinal dystrophy leading to congenital blindness. A recently identified LCA gene is NMNAT1, located in the LCA9 locus. Although most mutations in blindness genes are coding variations, there is accumulating evidence for hidden noncoding defects or structural variations (SVs). The starting point of this study was an LCA9‐associated consanguineous family in which no coding mutations were found in the LCA9 region. Exploring the untranslated regions of NMNAT1 revealed a novel homozygous 5′UTR variant, c.‐70A>T. Moreover, an adjacent 5′UTR variant, c.‐69C>T, was identified in a second consanguineous family displaying a similar phenotype. Both 5′UTR variants resulted in decreased NMNAT1 mRNA abundance in patients’ lymphocytes, and caused decreased luciferase activity in human retinal pigment epithelial RPE‐1 cells. Second, we unraveled pseudohomozygosity of a coding NMNAT1 mutation in two unrelated LCA patients by the identification of two distinct heterozygous partial NMNAT1 deletions. Molecular characterization of the breakpoint junctions revealed a complex Alu‐rich genomic architecture. Our study uncovered hidden genetic variation in NMNAT1‐associated LCA and emphasized a shift from coding to noncoding regulatory mutations and repeat‐mediated SVs in the molecular pathogenesis of heterogeneous recessive disorders such as hereditary blindness.  相似文献   
30.

Background

Heart failure (HF) is characterized by altered myocardial substrate metabolism which can lead to myocardial triglyceride accumulation (steatosis) and lipotoxicity. However its role in mild HF with preserved ejection fraction (HFpEF) is uncertain. We measured myocardial triglyceride content (MTG) in HFpEF and assessed its relationships with diastolic function and exercise capacity.

Methods

Twenty seven HFpEF (clinical features of HF, left ventricular EF >50%, evidence of mild diastolic dysfunction and evidence of exercise limitation as assessed by cardiopulmonary exercise test) and 14 controls underwent 1H-cardiovascular magnetic resonance spectroscopy (1H-CMRS) to measure MTG (lipid/water, %), 31P-CMRS to measure myocardial energetics (phosphocreatine-to-adenosine triphosphate - PCr/ATP) and feature-tracking cardiovascular magnetic resonance (CMR) imaging for diastolic strain rate.

Results

When compared to controls, HFpEF had 2.3 fold higher in MTG (1.45?±?0.25% vs. 0.64?±?0.16%, p?=?0.009) and reduced PCr/ATP (1.60?±?0.09 vs. 2.00?±?0.10, p?=?0.005). HFpEF had significantly reduced diastolic strain rate and maximal oxygen consumption (VO2 max), which both correlated significantly with elevated MTG and reduced PCr/ATP. On multivariate analyses, MTG was independently associated with diastolic strain rate while diastolic strain rate was independently associated with VO2 max.

Conclusions

Myocardial steatosis is pronounced in mild HFpEF, and is independently associated with impaired diastolic strain rate which is itself related to exercise capacity. Steatosis may adversely affect exercise capacity by indirect effect occurring via impairment in diastolic function. As such, myocardial triglyceride may become a potential therapeutic target to treat the increasing number of patients with HFpEF.
  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