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   37431篇
  免费   4183篇
  国内免费   1026篇
耳鼻咽喉   255篇
儿科学   487篇
妇产科学   465篇
基础医学   1589篇
口腔科学   707篇
临床医学   6938篇
内科学   3223篇
皮肤病学   419篇
神经病学   1143篇
特种医学   1032篇
外国民族医学   8篇
外科学   2581篇
综合类   4604篇
现状与发展   1篇
一般理论   5篇
预防医学   8652篇
眼科学   258篇
药学   6564篇
  115篇
中国医学   2587篇
肿瘤学   1007篇
  2024年   142篇
  2023年   1026篇
  2022年   1283篇
  2021年   2070篇
  2020年   2181篇
  2019年   1851篇
  2018年   1771篇
  2017年   1821篇
  2016年   1840篇
  2015年   1767篇
  2014年   2986篇
  2013年   3665篇
  2012年   2643篇
  2011年   2541篇
  2010年   1977篇
  2009年   1818篇
  2008年   1680篇
  2007年   1583篇
  2006年   1393篇
  2005年   1097篇
  2004年   883篇
  2003年   718篇
  2002年   576篇
  2001年   507篇
  2000年   388篇
  1999年   367篇
  1998年   307篇
  1997年   225篇
  1996年   226篇
  1995年   179篇
  1994年   158篇
  1993年   118篇
  1992年   136篇
  1991年   106篇
  1990年   85篇
  1989年   70篇
  1988年   68篇
  1987年   50篇
  1986年   59篇
  1985年   60篇
  1984年   54篇
  1983年   27篇
  1982年   24篇
  1981年   21篇
  1980年   33篇
  1979年   11篇
  1978年   18篇
  1977年   13篇
  1975年   7篇
  1974年   3篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
21.
《Value in health》2020,23(8):1027-1033
ObjectivesIn many countries, future unrelated medical costs occurring during life-years gained are excluded from economic evaluation, and benefits of unrelated medical care are implicitly included, leading to life-extending interventions being disproportionately favored over quality of life-improving interventions. This article provides a standardized framework for the inclusion of future unrelated medical costs and demonstrates how this framework can be applied in England and Wales.MethodsData sources are combined to construct estimates of per-capita National Health Service spending by age, sex, and time to death, and a framework is developed for adjusting these estimates for costs of related diseases. Using survival curves from 3 empirical examples illustrates how our estimates for unrelated National Health Service spending can be used to include unrelated medical costs in cost-effectiveness analysis and the impact depending on age, life-years gained, and baseline costs of the target group.ResultsOur results show that including future unrelated medical costs is feasible and standardizable. Empirical examples show that this inclusion leads to an increase in the ICER of between 7% and 13%.ConclusionsThis article contributes to the methodology debate over unrelated costs and how to systematically include them in economic evaluation. Results show that it is both important and possible to include future unrelated medical costs.  相似文献   
22.
《Vaccine》2020,38(19):3582-3590
BackgroundConcern about adverse events following immunization is frequently cited by both those who receive or decline vaccines. Neurological adverse events are especially concerning.ObjectivesOur aim was to detect associations between seasonal influenza vaccination and the occurrence of severe anesthesia/paresthesia or severe headaches.MethodsData were analyzed from the Canadian National Vaccine Safety network. Events occuring on days 0–7 were self-reported and prevented daily activity, led to school or work absenteeism, or required medical attention. Controls were the previous year’s vaccinees; events in controls were collected prior to the start of the influenza vaccination program of each year (2012/13 through 2016/17). Multivariable logistic regression was used to determine the association between seasonal influenza vaccination and the occurrence of anesthesia/paresthesia or severe headaches.ResultsThe total sample was 107,565 for investigating anesthesia/paresthesia and 97,420 for investigating severe headaches. Anesthesia/paresthesia was reported by 104/107,565 (0.10%) participants; 63/69,129 (0.09%) vaccinees and 41/38,436 (0.11%) controls (adjusted odds ratio (aOR) = 0.89; 95% CI = 0.60, 1.32). Severe headaches were reported by 1361/97,420 (1.40%) participants; 907/61,463 (1.48%) vaccinees and 454/35,957 (1.26%) controls (aOR = 1.21; 95% CI = 1.08, 1.36). No specific vaccine product was associated with severe headaches.ConclusionsOur study found no association between severe anesthesia/paresthesia and seasonal influenza vaccination. While there was an association with severe headaches as an adverse event following influenza vaccination, the rates of these events are similar to rates reported from clinical trials and are not a cause for additional concern.  相似文献   
23.
[目的] 系统评价八段锦治疗神经根型颈椎病的临床疗效。[方法] 计算机检索中国知网数据库(CNKI)、维普资讯中文科技期刊数据库(VIP)、万方数据库(Wan-fang)、中国生物医学文献数据库(SinoMed)、Web of science、Clinical Trials gov、Pubmed、EMBASE、CENTRAL、Cochrane Library,查找出八段锦治疗神经根型颈椎病的随机对照试验(RCT),检索时限均从建库至2019年7月1日。两名研究者按照纳入与排除标准独立进行文献筛选、资料提取和偏倚风险评估,应用RevMan 5.3软件对最后纳入的研究进行Meta分析。[结果] 最终纳入10个RCT,共843例患者。Meta分析结果显示:八段锦+常规治疗与常规治疗比较,其临床疗效的总有效率差异具有统计学意义[OR=4.19,95% CI(2.42,7.26),P<0.000 01];八段锦+常规治疗与常规治疗+颈部“米”字操比较,其临床疗效的总有效率差异具有统计学意义[OR=3.41,95% CI(1.56,7.46),P=0.002];八段锦+常规治疗与常规治疗比较,其疼痛视觉模拟评分法(VAS)评分差异具有统计学意义[MD=-1.90,95% CI(-1.97,-1.83),P<0.000 01]。[结论] 基于现有的研究,该系统评价显示,与常规治疗相比,八段锦+常规治疗在临床疗效总有效率、VAS评分方面有一定的治疗优势。与常规治疗+颈部“米”字操比较,八段锦+常规治疗在临床疗效的总有效率方面有一定的治疗优势。但由于纳入研究的质量不高,仍需要大样本、多中心、随机、双盲试验及试验参照CONSORT标准和STRICTA声明进行RCT研究。  相似文献   
24.
25.
26.
Precise data on food chemical composition is crucial for any quantitative nutrition research and indispensable for evaluation and planning of computer-based menus. Moreover, exact food chemical composition is of the utmost importance in composing specific diets that may be low in certain essential nutrients. Therefore, this research evaluated a weekly vegan menu using three different food composition databases (FCDB): the Croatian, the official Danish Food Composition Database and the United States Department of Agriculture (USDA) – National Nutrient Database for Standard Reference. Significant differences (p < 0.05) were determined in evaluated and optimised offers for the same menu when using different FCDBs. Furthermore, in these menus quantities of some nutrients have not reached official daily recommendations needed for prevention of non-communicable diseases. In this research, new vegan menus that can provide adequate quantity of essential nutrients, regardless of FCDB utilized, were created with linear optimisation (LO). This resulted in high quality daily menu offers. However, depending on the FCDB that was used, optimal menus differed in daily meal combinations, and the effectiveness of the optimisation in the minimisation of differences caused by differences of data in FCDBs was tested. Linear optimisation has been proved to be an effective tool in planning of specific diets, such as vegan diets. Nonetheless, the quality of computer-planned menus depends heavily on the quality of FCDB used.  相似文献   
27.
教育测量与评价对实现教育目标具有重要作用。科学的教育评价既促进学生学习,又为教育决策提供依据,以实现持续质量改进。"健康中国2030"的整体目标、医学科学的发展及人民的健康需求,对新时代护理人才的培养提出了更高、更具体的要求。高等护理院校应以国家和社会对护理人才需求、院校培养目标为导向,以测量理论为基础,制定完善的学业评定标准,科学地开展毕业考核,保证人才"出口"质量。毕业考核作为终结性评价,测试内容在评价质量中起核心作用,应符合国家护理学专业培养标准,并与院校培养目标、课程目标契合。院校应关注护理本科生毕业考核质量,在保障测试信度的同时,做到实施公平、评价适当、标准一致,以确保测试的效度。教育管理部门及各院校应优化评价体系,加强对护理本科生毕业管理,在充分开展系统调查与分析的基础上,基于胜任力导向和结果导向,建立综合性评价体系,在教学过程中进行全方位反馈评价管理。文章结合国内外护理学专业本科生毕业考核的现状,从考核目的、内容、方式、评价主体、质量控制等方面进行综述与分析,为我国加强护理学本科教育,完善护理学专业本科生毕业评价体系建设提供借鉴。  相似文献   
28.
29.
《Vaccine》2016,34(20):2349-2353
BackgroundIn October 2011, the Advisory Committee on Immunization Practices (ACIP) issued updated recommendations that all pregnant women routinely receive a dose of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine.ObjectivesWe characterized reports to the Vaccine Adverse Event Reporting System (VAERS) in pregnant women who received Tdap after this updated recommendation (2011–2015) and compared the pattern of adverse events (AEs) with the period before the updated recommendation (2005–2010).MethodsWe searched the VAERS database for reports of AEs in pregnant women who received Tdap vaccine after the routine recommendation (11/01/2011–6/30/2015) and compared it to published data before the routine Tdap recommendation (01/01/2005–06/30/2010). We conducted clinical review of reports and available medical records. The clinical pattern of reports in the post-recommendation period was compared with the pattern before the routine Tdap recommendation.ResultsWe found 392 reports of Tdap vaccination after the routine recommendation. One neonatal death but no maternal deaths were reported. No maternal or neonatal deaths were reported before the recommendation. We observed an increase in proportion of reports for stillbirths (1.5–2.8%) and injection site reactions/arm pain (4.5–11.9%) after the recommendation compared to the period before the routine recommendation for Tdap during pregnancy. We noted a decrease in reports of spontaneous abortion (16.7–1%). After the 2011 Tdap recommendation, in most reports, vaccination (79%) occurred during the third trimester compared to 4% before the 2011 Tdap recommendation. Twenty-six reports of repeat Tdap were received in VAERS; 13 did not report an AE. One medical facility accounted for 27% of all submitted reports.ConclusionsNo new or unexpected vaccine AEs were noted among pregnant women who received Tdap after routine recommendations for maternal Tdap vaccination. Changes in reporting patterns would be expected, given the broader use of Tdap in pregnant women in the third trimester.  相似文献   
30.
PurposeTo evaluate the potential differences in non-target embolization and vessel microsphere filling of a reflux-control microcatheter (RCM) compared to a standard end-hole microcatheter (SEHM) in a swine model.Materials and methodsRadiopaque microspheres were injected with both RCM and SEHM (2.4-Fr and 2.7-Fr) in the kidneys of a preclinical swine model. Transarterial renal embolization procedures with RCM or SEHM were performed in both kidneys of 14 pigs. Renal arteries were selectively embolized with an automated injection protocol of radio-opaque microspheres. Ex-vivo X-ray microtomography images of the kidneys were utilized to evaluate the embolization by quantification of the deposition of injected microspheres in the target vs. the non-target area of injection. X-ray microtomography images were blindly analyzed by five interventional radiologists. The degree of vessel filling and the non-target embolization were quantified using a scale from 1 to 5 for each parameter. An analysis of variance was used to compare the paired scores.ResultsTotal volumes of radio-opaque microspheres injected were similar for RCM (11.5 ± 3.6 [SD] mL; range: 6–17 mL) and SEHM (10.6 ± 5.2 [SD] mL; range: 4–19 mL) (P = 0.38). The voxels enhanced ratio in the target (T) vs. non-target (NT) areas was greater with RCM (T = 98.3% vs. NT = 1.7%) than with SEHM (T = 89% vs. NT = 11%) but the difference was not significant (P = 0.30). The total score blindly given by the five interventional radiologists was significantly different between RCM (12.3 ± 2.1 [SD]; range: 6–15) and the standard catheter (11.3 ± 2.5 [SD]; range: 4–15) (P = 0.0073), with a significant decrease of non-target embolization for RCM (3.8 ± 1.3 [SD]; range: 3.5–4.2) compared to SEHM (3.2 ± 1.5 [SD]; range: 2.9–3.5) (P = 0.014).ConclusionIn an animal model, RCM microcatheters reduce the risk of non-target embolization from 11% to 1.7%, increasing the delivery of microspheres of 98% to the target vessels, compared to SEHM microcatheters.  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