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   2842篇
  免费   198篇
  国内免费   15篇
耳鼻咽喉   9篇
儿科学   31篇
妇产科学   63篇
基础医学   417篇
口腔科学   30篇
临床医学   348篇
内科学   617篇
皮肤病学   22篇
神经病学   335篇
特种医学   126篇
外科学   352篇
综合类   4篇
一般理论   6篇
预防医学   149篇
眼科学   38篇
药学   191篇
中国医学   9篇
肿瘤学   308篇
  2024年   3篇
  2023年   24篇
  2022年   43篇
  2021年   96篇
  2020年   47篇
  2019年   84篇
  2018年   95篇
  2017年   81篇
  2016年   71篇
  2015年   103篇
  2014年   135篇
  2013年   174篇
  2012年   247篇
  2011年   262篇
  2010年   153篇
  2009年   117篇
  2008年   220篇
  2007年   206篇
  2006年   175篇
  2005年   189篇
  2004年   152篇
  2003年   141篇
  2002年   121篇
  2001年   15篇
  2000年   10篇
  1999年   12篇
  1998年   21篇
  1997年   13篇
  1996年   15篇
  1995年   3篇
  1994年   5篇
  1993年   5篇
  1992年   3篇
  1991年   4篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1982年   1篇
排序方式: 共有3055条查询结果,搜索用时 15 毫秒
91.
92.
93.
The pathophysiology of gait and balance disorders in elderly people with ‘higher level gait disorders’ (HLGD) is poorly understood. In this study, we aimed to identify the brain networks involved in this disorder. Standardised clinical scores, biomechanical parameters of gait initiation and brain imaging data, including deep white matter lesions (DWML) and brain voxel-based morphometry analyses, were assessed in 20 HLGD patients in comparison to 20 age-matched controls. In comparison to controls, HLGD patients presented a near-normal preparatory phase of gait initiation, but a severe alteration of both locomotor and postural parameters of first-step execution, which was related to ‘axial’ hypokinetic-rigid signs. HLGD patients showed a significant grey matter reduction in the mesencephalic locomotor region (MLR) and the left primary motor cortex. This midbrain atrophy was related to the severity of clinical and neurophysiologically determined balance deficits. HLGD patients also showed a reduction in speed of gait, related to ‘appendicular’ hypokinetic-rigid signs and frontal-lobe-like cognitive deficits. These last two symptoms were correlated with the severity of DWML, found in 12/20 HLGD patients. In conclusion, these data suggest that the gait and balance deficits in HLGD mainly result from the lesion or dysfunction of the network linking the primary motor cortex and the MLR, brain regions known to be involved in the control of gait and balance, whereas cognitive and ‘appendicular’ hypokinetic-rigid signs mainly result from DWML that could be responsible for a dysfunction of the frontal cortico-basal ganglia loops.  相似文献   
94.
The aim of the present study was to investigate how item-scene incongruity at encoding influences subsequent item recognition and the associated event-related potential (ERP) old/new effects. Participants (N = 26) studied pictures showing an item in a scene, either in a congruent condition (e.g., a tent in a field) or an incongruent condition (e.g., a shower cabin in a field). Items were presented alone at test. Behavioral data revealed a benefit of incongruent information, with greater source memory performance but no significant effect on old/new recognition judgments. Longer response times for old compared to new items showed that participants not only evaluated the old-new status of objects during recognition, but also worked already on the scene context decision relative to the source memory judgment. An ERP incongruity effect was found at study, with greater N400 amplitude in the incongruent condition than the congruent condition. During recognition, the results provide evidence that item-scene incongruity at study increases the amplitude of ERP old/new effects. A mid-frontal N400 old/new effect was found in the early time window (300–500 ms), and a right frontal sub-component was modulated by item-scene incongruity at encoding. The modulation observed in the later time window (500–800 ms) confirmed previous studies showing that the parietal old/new effect reflects the retrieval of episodic contextual details. The present study shows that the magnitude of ERP old/new effects is sensitive to item-scene incongruity at encoding from the early time window in the right frontal region to the later retrieval processes.  相似文献   
95.
96.
97.
A single multiplex PCR assay targeting seven virulence factors and the wzi gene specific for the K1 and K2 capsular serotypes of Klebsiella pneumoniae was developed and tested on 65 clinical isolates, which included 45 isolates responsible for community-acquired severe human infections. The assay is useful for the surveillance of emerging highly virulent strains.  相似文献   
98.
We describe an exceptional case of life-threatening group A Escherichia coli-induced purpura fulminans. Genotyping of common polymorphisms in genes involved in innate immunity or coagulation did not reveal known susceptibility to such a manifestation. Genetic analysis of the strain revealed an unusual conserved virulence plasmidic region, pointing out its potential virulence.  相似文献   
99.
The aim of this study is to assess the long-term effectiveness and safety of IL1Ra in Schnitzler syndrome (SchS). Between 2010 and 2012, we performed a nationwide survey among French internal medicine departments to identify SchS patients. We retrospectively analyzed the long-term efficacy and safety of IL1Ra and the outcome of patients that did not receive this treatment. Forty-two patients were included in the study, 29 of whom received IL1Ra. The mean age at disease onset was 59.9 years. Disease manifestations included urticaria (100%), fever (76%), bone/joint pain (86%), bone lesions (76%), anemia (67%), and weight loss (60%). The monoclonal gammopathy was overwhelmingly IgM kappa (83%). The mean follow-up was 9.5 years (range: 1.6-35). Two patients developed Waldenström's macroglobulinemia and one developed AA amyloidosis. All of the 29 patients who received IL1Ra responded dramatically. After a median follow-up of 36 months (range: 2-79), the effectiveness remained unchanged. All patients remained on anti-IL-1 therapy. Twenty-four patients (83%) went into complete remission and five (17%) into partial remission. Three patients experienced grade 3-4 neutropenia. Six patients developed severe infections. No lymphoproliferative diseases occurred while on IL1Ra. When last seen, all patients without anakinra had an active disease with variable impact on their quality of life. Their median corticosteroids dosage was 6 mg/d (range: 5-25). IL1Ra is effective in SchS, with a sharp corticosteroid-sparing effect. Treatment failures should lead to reconsider the diagnosis. Long-term follow-up revealed no loss of effectiveness and a favorable tolerance profile. The long-term effects on the risk of hemopathy remain unknown.  相似文献   
100.
BackgroundPatient self-assessment via a mobile app detects actionable symptoms and has been shown to detect lung cancer relapses early, thereby lengthening survival.ObjectiveThe purpose of this study was to assess the incidence of chief symptoms associated with the main tobacco-induced pathologies in both current and ex-smokers through a self-assessment smartphone app and to evaluate the app’s capacity to encourage users to quit smoking or reduce consumption, as well as its impact on early lung cancer stages at the time of diagnosis.MethodsCurrent and ex-smokers were recruited through an advertising campaign in Sarthe county (France) proposing the free download of a smartphone app. App users were asked to answer 13 questions related to symptoms associated with tobacco-induced diseases (chronic obstructive pulmonary disease [COPD], cardiovascular diseases, cancer). In the event of any positive answer, a message was displayed recommending the user to consult a physician. In addition, they were asked about smoking cessation intention before and after answering these 13 questions. Finally, incidence of stage 1 or 2 lung cancers diagnosed during the launch period of our application was evaluated by comparing data from various sources to those from the same period during the previous year.ResultsOf the 5671 users who were eligible for evaluation, an alert was sent to the majority (4118/5671, 72.6%), with a higher incidence for current smokers (2833/3679, 77.0% vs 1298/1992, 65.2%; P<.001). The most frequent symptoms triggering the notifications were fatigue (2023/5671, 35.7%), cough (1658/5671, 29.2%), dyspnea (1502/5671, 26.5%), and persistent chest pain (1286/5671, 22.7%). Of the current smokers, 14.0% (515/3679) showed symptoms suggesting COPD, 15.5% (571/3679) showed symptoms suggesting stable angina, 12.4% (455/3679) probably had lower extremity artery disease, and 6.8% (249/3679) had possible cancer. Of the users, 36.5% (1343/3679) claimed that they thought about quitting smoking, and 48.7% (1795/3679) had thought about reducing their consumption. Surgery-eligible stage 1 and 2 lung cancer incidence was 24% (14/58) during the study period versus 9% (5/54) during the previous year in Sarthe county (P=.04), whereas it remained unchanged in the neighboring county of Maine-et-Loire.ConclusionsA majority of current and ex-smokers showed worrying symptoms, and the use of a self-assessment smartphone app may drive a majority of smokers toward the intention of smoking cessation or decreasing consumption. A randomized study should be performed to confirm this intention and to support the potential increase of symptomatic lung cancer detection at early, surgery-accessible stages.Trial RegistrationClinicalTrials.gov NCT04048954; https://www.clinicaltrials.gov/ct2/show/NCT04048954  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