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   149691篇
  免费   12018篇
  国内免费   3507篇
耳鼻咽喉   832篇
儿科学   2826篇
妇产科学   1348篇
基础医学   6318篇
口腔科学   4753篇
临床医学   20112篇
内科学   31274篇
皮肤病学   1709篇
神经病学   6964篇
特种医学   4498篇
外国民族医学   25篇
外科学   12995篇
综合类   26930篇
现状与发展   14篇
一般理论   4篇
预防医学   11060篇
眼科学   1550篇
药学   13936篇
  283篇
中国医学   11282篇
肿瘤学   6503篇
  2024年   184篇
  2023年   2494篇
  2022年   3320篇
  2021年   6437篇
  2020年   6749篇
  2019年   5254篇
  2018年   5057篇
  2017年   5243篇
  2016年   5801篇
  2015年   5633篇
  2014年   11356篇
  2013年   13601篇
  2012年   10508篇
  2011年   10827篇
  2010年   8736篇
  2009年   7634篇
  2008年   7065篇
  2007年   7440篇
  2006年   6357篇
  2005年   5408篇
  2004年   4369篇
  2003年   3718篇
  2002年   3107篇
  2001年   2607篇
  2000年   2110篇
  1999年   1732篇
  1998年   1574篇
  1997年   1484篇
  1996年   1015篇
  1995年   1073篇
  1994年   935篇
  1993年   838篇
  1992年   695篇
  1991年   619篇
  1990年   466篇
  1989年   452篇
  1988年   425篇
  1987年   384篇
  1986年   327篇
  1985年   416篇
  1984年   324篇
  1983年   214篇
  1982年   274篇
  1981年   219篇
  1980年   172篇
  1979年   163篇
  1978年   91篇
  1977年   89篇
  1976年   66篇
  1975年   49篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
《Cancer radiothérapie》2022,26(4):611-615
In order to provide more convenient irradiation regimens for patient comfort, radiation facility organization and health expenses, new hypofractionated protocols have been evaluated. Moderately (dose/fraction: 2.3 to 3 Gy), then ultra (dose/fraction: 5.2 to 6.1 Gy) hypofractionated irradiations were first validated. The current question is: is it possible to go forward using extreme hypofractionated regimens (EHR) based on 1 to 3 fractions. Different irradiation techniques are under investigation. However, brachytherapy remains the smartest way to deliver a high dose in a small volume. We report prospective and retrospective study results which evaluated EHR for breast and prostate brachytherapy. While oncological outcome and toxicity profile appear extremely encouraging for low-risk breast cancer after a 1 to 4 fractions (6.25 to 20 Gy/fraction), the use of a single fraction of 19 to 23 Gy appears debatable for prostate cancer. Brachytherapy represents an emblematic example of EHR but longer follow-up and more mature results are awaited in order to specify the right indications and refine the EQD2 calculation method including new biological and technical factors.  相似文献   
2.
BackgroundVoices for Food was a longitudinal community, food pantry–based intervention informed by the social ecological model, and designed to improve food security, dietary intake, and quality among clients, which was carried out in 24 rural food pantries across 6 Midwestern states.ObjectiveOur objective was to evaluate changes in adult food security, dietary intake, and quality from baseline (2014) to follow-up (2016), and to assess the role of adult food security on dietary outcomes.DesignA multistate, longitudinal, quasi-experimental intervention with matched treatment and comparison design was used to evaluate treatment vs comparison group changes over time and changes in both groups over time.Participants/settingAdult food pantry clients (n = 617) completed a demographic food security survey, and up to three 24-hour dietary recalls at baseline (n = 590) and follow-up (n = 160).InterventionCommunity coaching served as the experimental component, which only “treatment” communities received, and a food council guide and food pantry toolkit were provided to both “treatment” and matched “comparison” communities.Main outcome measuresChange in adult food security status, mean usual intakes of nutrients and food groups, and Healthy Eating Index-2010 scores were the main outcome measures.Statistical analyses performedLinear mixed models estimated changes in outcomes by intervention group and by adult food security status over time.ResultsImprovements in adult food security score (–0.7 ± 0.3; P = .01), Healthy Eating Index-2010 total score (4.2 ± 1.1; P < .0001), and empty calories component score (3.4 ± 0.5; P <.0001) from baseline to follow-up were observed in treatment and comparison groups, but no statistically significant changes were found for adult food security status, dietary quality, and usual intakes of nutrients and food groups between the 2 groups over time. The intervention effect on dietary quality and usual intake changes over time by adult food security status were also not observed.ConclusionsFood pantry clients in treatment and comparison groups had higher food security and dietary quality at the follow-up evaluation of the Voices for Food intervention trial compared with baseline, despite the lack of difference among the groups as a result of the experimental coaching component.  相似文献   
3.
4.
目的 探讨胆囊结石合并胆总管结石(CBDS)术后患者复发情况及危险因素。方法 纳入114例2019年1月~2020年12月在本院行ECRP联合LC治疗的胆囊结石合并CBDS患者,回顾性分析其临床资料,根据所选患者ECRP联合LC术后随访1年内是否复发(REC)将其分为REC组(32例)和未REC组(82例)。回顾性统计胆囊结石合并CBDS术后患者REC情况,比较REC组和未REC组的临床资料,并分析胆囊结石合并CBDS术后患者REC的危险因素。结果 114例胆囊结石合并CBDS术后患者REC32例,发生率28.07%。胆囊结石合并CBDS术后患者REC的危险因素为胆道感染、胆道口括约肌切开、术者经验≤3年、胆道括约肌功能障碍(OR=4.170、4.047、3.568、3.367,P<0.05)。结论 胆囊结石合并CBDS术后患者REC的危险因素与胆道感染、胆道口括约肌切开、术者经验≤3年、胆道括约肌功能障碍密切相关,可据此针对性制定临床治疗及护理干预措施方案,以降低胆囊结石合并CBDS术后患者REC率。  相似文献   
5.
6.
目的 分析不同特征的结直肠癌患者就医行为选择在中医院(含中西医结合医院)、西医院及肿瘤专科医院间的差异,为合理引导结直肠癌患者适宜就医及制订相关政策提供依据。方法 收集北京地区2018年1月-2019年12月17家三级甲等医院21894例首诊结直肠癌成年住院患者的病案首页数据,采用EmpowerStats 2.0对数据进行描述性分析。结果 21894例结直肠癌患者中就诊于中医院的有862例(3.93%),西医院的有8723例(39.85%),肿瘤专科医院的有12309例(56.22%)。对于不同医疗机构,男性占比均大于女性,58-68岁患者占比最大。且结直肠癌患者年龄、医疗付款方式及肿瘤分期在不同医疗机构间的分布存在差异(P<0.001)。西医院及肿瘤专科医院结直肠癌Ⅲ期患者占比最大,而就诊于中医院患者中结直肠癌Ⅳ期最多。从地域分布来看,异地就诊比例(57.32%)大于本地,且就诊于肿瘤专科医院的患者中73.66%来自外地。患者来源前三名分别是北京市、河北省及内蒙古自治区。而在北京市内,西医院患者主要来源于朝阳区、海淀区及西城区,中医院患者主要来源于海淀区、朝阳区及丰台区,肿瘤专科医院则主要来源于朝阳区、海淀区及丰台区。结论 应大力倡导年轻以及早期结直肠癌患者向中医院分流,充分施展中医药在结直肠癌患者中的治疗优势;发挥三级医院带动作用,建立对口帮扶医院,减少不必要的跨省流动及提倡结直肠癌的早筛早治,以降低结直肠癌死亡率。  相似文献   
7.
8.
姚海艳  史珣瑜  施江 《全科护理》2021,19(4):566-569
目的:探讨经皮冠状动脉介入(PCI)术后病人的体力活动水平及其影响因素。方法:选择常州市三级甲等综合医院心内科接受PCI治疗的冠心病病人,收集资料,分析PCI术后冠心病病人体力活动动机、体力活动和自我效能现状;冠心病病人自我效能、体力活动动机与体力活动的相关性,并分析影响PCI术后病人体力活动水平的相关危险因素。结果:共发放调查问卷400份,回收400份,有效率为94.75%(379/400);379例冠心病病人术后每周体力活动为(3570.85±314.19)MET-min,以低、中强度为主;冠心病病人术后自我效能总分、体力活动动机总分与体力活动呈正相关(P<0.05);体质指数(BMI)、PCI次数≥2次、年龄、PCI支架数量≥3枚、自我效能、体力活动动机是影响PCI术后冠心病病人体力活动水平的高危因素(OR>1且P<0.05)。结论:PCI术后病人体力活动水平处于较低的水平,PCI次数、BMI、年龄、PCI支架数量、自我效能、体力活动动机是影响PCI术后冠心病病人体力活动水平的高危因素,临床需针对各高危因素制定相应的干预措施,提高病人体力活动水平。  相似文献   
9.
10.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  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