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   12088篇
  免费   1117篇
  国内免费   218篇
耳鼻咽喉   88篇
儿科学   180篇
妇产科学   311篇
基础医学   1360篇
口腔科学   144篇
临床医学   826篇
内科学   1397篇
皮肤病学   75篇
神经病学   672篇
特种医学   1031篇
外国民族医学   2篇
外科学   570篇
综合类   1283篇
一般理论   1篇
预防医学   855篇
眼科学   70篇
药学   2547篇
  9篇
中国医学   798篇
肿瘤学   1204篇
  2023年   181篇
  2022年   258篇
  2021年   589篇
  2020年   441篇
  2019年   399篇
  2018年   379篇
  2017年   418篇
  2016年   449篇
  2015年   489篇
  2014年   735篇
  2013年   789篇
  2012年   712篇
  2011年   688篇
  2010年   582篇
  2009年   521篇
  2008年   567篇
  2007年   569篇
  2006年   458篇
  2005年   418篇
  2004年   389篇
  2003年   371篇
  2002年   305篇
  2001年   287篇
  2000年   231篇
  1999年   215篇
  1998年   157篇
  1997年   129篇
  1996年   120篇
  1995年   138篇
  1994年   130篇
  1993年   113篇
  1992年   130篇
  1991年   144篇
  1990年   140篇
  1989年   80篇
  1988年   86篇
  1987年   72篇
  1986年   63篇
  1985年   68篇
  1984年   77篇
  1983年   50篇
  1982年   45篇
  1981年   39篇
  1980年   39篇
  1979年   36篇
  1978年   25篇
  1977年   24篇
  1976年   12篇
  1974年   12篇
  1973年   12篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Excellence in teaching and learning is fundamental to the provision of quality training for doctors and for this a sound knowledge of the principles of adult learning theory is important. We present an educational course in head and neck trauma skills for emergency medicine (EM) registrars, using the pedagogical principle of active learning. Our aim was to provide trainees with skills in the evaluation and management of hard and soft tissue injuries to the head, neck, and mouth. Active learning has been shown to provide a superior experience in classrooms, creating a ‘deep’ understanding of the material. To maximise learning, we used these principles to develop small group seminars led by a diverse range of teachers that allowed trainees to acquire hands-on skills. Questionnaires that were completed before and after the course showed an appreciable educational impact. We conclude that innovative teaching methods facilitate the sharing of knowledge that will benefit patient care.  相似文献   
2.
目的 国家印发《关于促进中医药传承创新发展的意见》指出要依托现有资源建设国家和省级中医药数据中心,以信息化支撑中医药服务体系建设。本文提出活态中医药传统知识数据库的构建思路和具体实施,为推动中医药知识信息化和推广中医药保护提供参考。方法 主要采用文献分析法了解国外数据库进展,梳理国内中医药数据库运行经验,剖析活态中医药传统知识数据库的建设和运行的实际问题,明确数据库建设思路与意义。结果 国家利用资源建立中医药传统知识保护数据库,信息化在知识的保护和传承创新方面发挥一定的作用,但世界上许多传统知识较为丰富的国家和地区,如印度、韩国等已经走在在传统知识数据保护的前列,我国数据库建设和应用仍需要研究、探索和改善,中医药传统知识的保护和分类建设亟需加强,数据信息挖掘与共享合作等规范需要确立。结论 国家高度重视中医药的传承与发展,要以信息化支撑中医药传统知识体系建设,活态中医药传统知识数据库系统帮助数据信息收集整理的同时,也对中医药传统知识的专家人才队伍和技术标准化体系建设有积极作用,以及将来中医药行业规范化建设形成坚实的数据基础。  相似文献   
3.
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.  相似文献   
4.
5.
We read with interest the commentary by Skeldon and Dijk about our article “Weekly, seasonal and chronotype-dependent variation of dim light melatonin onset.” The discussion points raised by Skeldon and Dijk are currently among the most hotly debated in human circadian science. What external factors determine human phase of entrainment? How great is the contribution of natural versus artificial light and sun time versus social time? Our intra-individual data add to the still limited evidence from field studies in this matter. In their commentary, Skeldon and Dijk formulate two either-or hypotheses, postulating that humans entrain either solely to the natural light-dark cycle (sun time referenced by midday) (H1) or solely to the light selected by local clock time and social constraints (H2). Neither hypothesis accounts for the effect of season on human light exposure. We interpreted our findings along more complex lines, speculating that the 1-h earlier melatonin rise in summer found in our sample is likely the combined result of daylight saving time (DST)-induced behavioral advances and a stronger natural zeitgeber in summer (light exposure determined by social and seasonal factors, Horiginal). Here, we show how the criticism by Skeldon and Dijk is based on two sentences quoted out of context (misrepresenting our hypothesis as H1) and that their hypothesis H2 leaves out important seasonal components in light exposure.  相似文献   
6.
IntroductionSeptic arthritis is a serious orthopaedic emergency that must be diagnosed and managed early to prevent devastating complications. The current gold standard for diagnosing septic arthritis is synovial fluid culture, but results are delayed by 48–72 h, and the sensitivity of the test is very low. Differentiating Septic from non-septic arthritis is vital to prevent unnecessary use of antibiotics and prevent complications. Serum Procalcitonin (PCT) is a useful marker in differentiating septic from non-septic arthritis but there are very few studies that have studied the role of synovial PCT for the same.AimTo determine the role of serum and synovial PCT in differentiating acute Septic from non-septic arthritis.Materials and methodsProspective clinical study in which 60 patients presenting with acute inflammatory arthritis (<2 weeks duration) were enrolled from May 2018 to May 2020. Serum and synovial fluid samples were drawn at presentation and routine blood investigations, synovial fluid culture sensitivity, and Procalcitonin levels were measured. Patients were divided into 3 groups, with group-1 having confirmed pyogenic, group-2 having presumed pyogenic, and group-3 having non –pyogenic patients, respectively. All data was tabulated and statistically analysed using appropriate tests.ResultsMean serum PCT values in groups 1, 2 and 3 were 1.06 ± 1.11, 0.85 ± 0.74, and 0.11 ± 0.24, respectively. Patients in the Pyogenic group (group1 and group 2) had significantly higher mean serum PCT as compared to group3 (p < 0.0001). Group 1 had higher serum PCT as compared to group 2, but the difference was not significant (p = 0.58). Mean synovial PCT in group 1, 2 and 3 were 2.42 ± 1.98, 1.89 ± 1.18, and 0.22 ± 0.40, respectively. Patients in the Pyogenic group (Group1 and Group2) had significantly higher mean synovial PCT as compared to Group 3 (p < 0.0001). Group 1 had higher mean synovial PCT as compared to group 2, but the difference was not significant (p = 0.54). The area under the ROC curve of the serum levels of PCT was 0.0.895, and the area under the ROC curve of the synovial fluid levels of PCT was 0.914, which was higher than the serum PCT level.ConclusionSerum and synovial Procalcitonin may be used as a diagnostic marker in differentiating septic from inflammatory arthritis and can help in reducing unnecessary use of antibiotics and early diagnosis and management of septic arthritis, thereby preventing complications.  相似文献   
7.
Suicides by pentobarbital overdose have increased since about 2012, which appear to be influenced by technical information on active euthanasia that has spread over the Internet. We encountered a pentobarbital poisoning case of a patient with amyotrophic lateral sclerosis. A caregiver found the patient unconscious immediately after two visitors left the room. The patient was immediately transferred to the emergency hospital but eventually declared dead. A fatal concentration of pentobarbital was detected in peripheral blood samples collected in the emergency hospital and during autopsy (53.8 μg/mL and 29.4 μg/mL, respectively). Because the ratios of pentobarbital concentrations between the gastric contents and peripheral blood were 35 and 29 in the hospital and autopsy samples, respectively, it is likely that pentobarbital was administered via the gastrostomy tube. The patient had contacted the visitors through social media. Although the patient had requested the doctor perform active euthanasia and expressed a desire to end their life on social media, nobody had noticed the plan to commit suicide.  相似文献   
8.
Quantitative susceptibility mapping (QSM) has the potential for being a biomarker for various diseases because of its ability to measure tissue susceptibility related to iron deposition, myelin, and hemorrhage from the phase signal of a T2*-weighted MRI. Despite its promise as a quantitative marker, QSM is faced with many challenges, including its dependence on preprocessing of the raw phase data, the relatively weak tissue signal, and the inherently ill posed relationship between the magnetic dipole and measured phase. The goal of this study was to evaluate the effects of background field removal and dipole inversion algorithms on noise characteristics, image uniformity, and structural contrast for cerebral microbleed (CMB) quantification at both 3T and 7T. We selected four widely used background phase removal and five dipole field inversion algorithms for QSM and applied them to volunteers and patients with CMBs, who were scanned at two different field strengths, with ground truth QSM reference calculated using multiple orientation scans. 7T MRI provided QSM images with lower noise than did 3T MRI. QSIP and VSHARP + iLSQR achieved the highest white matter homogeneity and vein contrast, with QSIP also providing the highest CMB contrast. Compared with ground truth COSMOS QSM images, overall good correlations between susceptibility values of dipole inversion algorithms and the COSMOS reference were observed in basal ganglia regions, with VSHARP + iLSQR achieving the susceptibility values most similar to COSMOS across all regions. This study can provide guidance for selecting the most appropriate QSM processing pipeline based on the application of interest and scanner field strength.  相似文献   
9.
10.
The aim of this study was to explore effects of a major urban reconstruction on physical activity (PA) behavior by comparing PA intensity hotspots before and after the tunneling of a highway with a new infrastructure prioritized for walking and cycling. In total, 126 individuals participated before and after the tunneling. GPS loggers and accelerometers were used to assess location and PA levels. A geographic information system (GIS) was used to perform optimized hotspot analyses on PA data, both on transport and stationary data points. The results showed several changes in PA hotspots on trip data, even if total PA levels did not change. At follow-up, PA intensity hotspots were more connected, with the new infrastructure as a central connection. This was true for higher and lower educated individuals. Therefore, if changes in the built environment do not result in changes on population-level outcomes, this does not imply that they have no impact on behavior.  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