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   1821篇
  免费   119篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   85篇
妇产科学   32篇
基础医学   273篇
口腔科学   118篇
临床医学   115篇
内科学   427篇
皮肤病学   66篇
神经病学   174篇
特种医学   27篇
外国民族医学   2篇
外科学   127篇
综合类   10篇
一般理论   1篇
预防医学   182篇
眼科学   58篇
药学   159篇
中国医学   6篇
肿瘤学   78篇
  2023年   20篇
  2022年   36篇
  2021年   56篇
  2020年   36篇
  2019年   50篇
  2018年   48篇
  2017年   36篇
  2016年   49篇
  2015年   55篇
  2014年   72篇
  2013年   93篇
  2012年   137篇
  2011年   146篇
  2010年   105篇
  2009年   77篇
  2008年   112篇
  2007年   131篇
  2006年   122篇
  2005年   108篇
  2004年   81篇
  2003年   85篇
  2002年   95篇
  2001年   10篇
  2000年   6篇
  1999年   10篇
  1998年   14篇
  1997年   12篇
  1996年   10篇
  1995年   6篇
  1994年   3篇
  1993年   5篇
  1992年   5篇
  1991年   8篇
  1990年   7篇
  1989年   5篇
  1988年   8篇
  1986年   3篇
  1985年   4篇
  1984年   4篇
  1982年   7篇
  1981年   9篇
  1980年   5篇
  1978年   4篇
  1976年   9篇
  1974年   8篇
  1973年   5篇
  1972年   4篇
  1971年   3篇
  1969年   2篇
  1968年   2篇
排序方式: 共有1943条查询结果,搜索用时 15 毫秒
61.
62.
Harrison  Mark  Bansback  Nick  Aguiar  Magda  Koehn  Cheryl  Shojania  Kam  Finckh  Axel  Hudson  Marie 《Clinical rheumatology》2020,39(10):2931-2941
Clinical Rheumatology - To elicit and compare preferences of patients and first-degree relatives and rheumatologists for preventive treatments for rheumatoid arthritis, understand the...  相似文献   
63.

Rationale and objectives

General practitioners (GPs) play an important role in management of patients at risk of osteoporosis (OP). The objectives were to assess (1) knowledge about OP and use of OP clinical guideline in comparison with other information sources and (2) association between the use of individual information sources and knowledge and self-reported quality of care among GPs.

Methods

Survey among random sample of Czech GPs was performed to find out their attitudes and role in OP management. The return rate of the postal questionnaire was 38% (525 respondents). Quality of care was assessed using three indicators: suspicion on OP, referral to the specialist and initial check-up.

Results

Respondents (median age 52 years, 59% women) had a very good knowledge of several risk factors, while others, namely low body mass index, history of hip fracture in mother and smoking were perceived as risk factors by only 40%, 45% and 55% of respondents, respectively. 10% of GPs stated the correct answer regarding daily calcium intake recommended for postmenopausal women. The OP guideline was considered accessible by 83% of respondents and used repeatedly by 54%. Use of the guideline correlated positively with knowledge score (P < 0.001), while use of each individual other source of information did not. Use of the guideline correlated with all three indicators of quality of care. Use of each other information source correlated only with a maximum of two indicators.

Conclusion

We identified areas of insufficient knowledge that should be targeted in educational activities for GPs. It is recommended to further motivate GPs to use their clinical guidelines regularly.  相似文献   
64.
65.
Recent neuroscientific research has demonstrated that both healthy and pathological aging induces alterations in the co-operative capacity of neuronal populations in the brain. Both compensatory and neurodegenerative mechanisms contribute to neurophysiological synchronization patterns, which provide a valuable marker for age-related cognitive decline. In this study, we propose that neuroplasticity-based training may facilitate coherent interaction of distant brain regions and consequently enhance cognitive performance in elderly people. If this is true, this would make neurophysiological synchronization a valid outcome measure to assess the efficacy of non-pharmacological interventions to prevent or delay age-related cognitive decline. The present study aims at providing an objective, synchronization-based tool to assess cognitive and/or physical interventions, adopting the notion of Relative Wavelet Entropy. This mathematical model employs a robust and parameter-free synchronization metric. By using data mining techniques, a distance value was computed for all participants so as to quantify the proximity of their individual profile to the mean group synchronization increase. In support of our hypothesis, results showed a significant increase in synchronization, for four electrode pairs, in the intervention group as compared to the active control group. It is concluded that the novel introduction of neurophysiological synchronization features could be used as a valid and reliable outcome measure; while the distance-based analysis could provide a reliable means of evaluating individual benefits.  相似文献   
66.
Background: Cheiloscopy is a comparatively recent counterpart to the long established dactyloscopic studies. Ethnic variability of these lip groove patterns has not yet been explored.

Aim: This study was a collaborative effort aimed at establishing cheiloscopic variations amongst modern human populations from four geographically and culturally far removed nations: India, Saudi Arabia, Spain and Nigeria.

Subjects and methods: Lip prints from a total of 754 subjects were collected and each was divided into four equal quadrants. The patterns were classified into six regular types (A–F), while some patterns which could not be fitted into the regular ones were segregated into G groups (G-0, G-1, G-2). Furthermore, co-dominance of more than one pattern type in a single quadrant forced us to identify the combination (COM, G-COM) patterns.

Results and conclusion: The remarkable feature noted after compilation of the data included pattern C (a bifurcate/branched prototype extending the entire height of the lip) being a frequent feature of the lips of all the populations studied, save for the Nigerian population in which it was completely absent and which showed a tendency for pattern A (a vertical linear groove) and a significantly higher susceptibility for combination (COM) patterns. Chi-square test and correspondence analysis applied to the frequency of patterns appearing in the defined topographical areas indicated a significant variation for the populations studied.  相似文献   

67.
68.
Refractive errors are common eye disorders characterized by a mismatch between the focal power of the eye and its axial length. An increased axial length is a common cause of the refractive error myopia (nearsightedness). The substantial increase in myopia prevalence over the last decades has raised public health concerns because myopia can lead to severe ocular complications later in life. Genomewide association studies (GWAS) have made considerable contributions to the understanding of the genetic architecture of refractive errors. Among the hundreds of genetic variants identified, common variants near the gap junction delta-2 (GJD2) gene have consistently been reported as one of the top hits. GJD2 encodes the connexin 36 (Cx36) protein, which forms gap junction channels and is highly expressed in the neural retina. In this review, we provide current evidence that links GJD2(Cx36) to the development of myopia. We summarize the gap junctional communication in the eye and the specific role of GJD2(Cx36) in retinal processing of visual signals. Finally, we discuss the pathways involving dopamine and gap junction phosphorylation and coupling as potential mechanisms that may explain the role of GJD2(Cx36) in refractive error development.  相似文献   
69.
Immunohistochemical studies were performed in synovial tissues from 40 patients with rheumatoid arthritis (RA), 9 with juvenile rheumatoid arthritis (JRA), 7 with psoriatic arthritis, and 4 with various rheumatic diseases. Overall synthesis of IgG– and/or IgM–rheumatoid factor (RF) was found in all patients with seropositive RA and JRA, in 75% of patients with seronegative RA, and in 1 patient with psoriatic arthritis. Agglutinator producing cells were found in 77% of the samples from seropositive RA and in 44% and 56% from seronegative RA and JRA patients, respectively. The percentage of IgG plasma cells synthesizing one or more of the 5 types of agglutinators studied was approximately 10% of plasma cells synthesizing IgG–RF. Intercellular and intracellular immune complex deposits were also found in patients with seropositive and seronegative RA and JRA. These findings suggest that synthesis of agglutinators by synovial tissue plasma cells of RA and JRA patients is a distinct—but definitely less prominent—function than that of RF synthesis.  相似文献   
70.
ObjectivesThe purpose of the study was to investigate the impact of oral anticoagulation (OAC) type on clinical outcomes 1 year after transcatheter aortic valve replacement (TAVR).BackgroundNon–vitamin K oral anticoagulants (NOACs) are superior to vitamin K antagonists (VKAs) in nonvalvular atrial fibrillation (AF), while their comparative performance among patients in need of OAC undergoing TAVR is underinvestigated.MethodsThe study enrolled 962 consecutive patients who underwent TAVR in 4 tertiary European centers and were discharged on either NOACs (n = 326) or VKAs (n = 636). By using propensity scores for inverse probability of treatment weighting (IPTW), the comparison of treatment groups was adjusted to correct for potential confounding.ResultsMean age and Society of Thoracic Surgeons score of the population were 81.3 ± 6.3 years and 4.5% (interquartile range: 3.0% to 7.3%); 52.5% were women and a balloon-expandable valve was used in 62.7% of cases. The primary outcome of interest, combined incidence of all-cause mortality, myocardial infarction, and any cerebrovascular event at 1-year after TAVR, was 21.2% with NOACs versus 15.0% with VKAs (hazard ratio [HR]: 1.44; 95% confidence interval [CI]: 1.00 to 2.07; p = 0.050, IPTW-adjusted). The 1-year incidence of any Bleeding Academic Research Consortium bleeds and all-cause mortality were comparable between the NOAC and VKA groups, 33.9% versus 34.1% (HR: 0.97; 95% CI: 0.74 to 1.26; p = 0.838, IPTW-adjusted) and 16.5% versus 12.2% (HR: 1.36; 95% CI: 0.90 to 2.06; p = 0.136, IPTW-adjusted), respectively.ConclusionsChronic use of both NOACs and VKAs among patients in need of OAC after TAVR are comparable regarding 1-year bleeding risk. The higher ischemic event rate observed with NOACs needs to be evaluated in large randomized trials.  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