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   15664篇
  免费   1267篇
  国内免费   123篇
耳鼻咽喉   40篇
儿科学   233篇
妇产科学   148篇
基础医学   383篇
口腔科学   175篇
临床医学   2491篇
内科学   1407篇
皮肤病学   81篇
神经病学   706篇
特种医学   232篇
外科学   928篇
综合类   3048篇
一般理论   1篇
预防医学   5574篇
眼科学   73篇
药学   1001篇
  25篇
中国医学   194篇
肿瘤学   314篇
  2024年   11篇
  2023年   335篇
  2022年   443篇
  2021年   757篇
  2020年   893篇
  2019年   750篇
  2018年   696篇
  2017年   618篇
  2016年   535篇
  2015年   543篇
  2014年   1246篇
  2013年   1269篇
  2012年   1152篇
  2011年   1189篇
  2010年   916篇
  2009年   749篇
  2008年   803篇
  2007年   827篇
  2006年   683篇
  2005年   556篇
  2004年   417篇
  2003年   348篇
  2002年   250篇
  2001年   214篇
  2000年   197篇
  1999年   114篇
  1998年   88篇
  1997年   91篇
  1996年   69篇
  1995年   33篇
  1994年   47篇
  1993年   33篇
  1992年   19篇
  1991年   19篇
  1990年   16篇
  1989年   12篇
  1988年   13篇
  1987年   12篇
  1986年   5篇
  1985年   16篇
  1984年   15篇
  1983年   8篇
  1982年   6篇
  1981年   9篇
  1980年   3篇
  1979年   8篇
  1978年   6篇
  1976年   7篇
  1975年   2篇
  1974年   3篇
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
1.
2.
AimThe purpose of this integrative review is to provide a comprehensive review of ethical considerations for host communities and nursing programs in planning, implementing and evaluating global health experiences for nursing students.BackgroundGlobal health experiences for nursing students are proliferating rapidly across university settings while at the same time decreasing the average time spent in the host country engaged with local communities. Global health experiences are an area where students can experience ethics as it is applied across varied contexts including resource limited international settings. As nursing education expands its global programming, exploring the ethical implications of designing, implementing and evaluating GHEs becomes pivotal to build respectful, sustainable relationships with global partners and best prepare nursing students for ethical professional practice in an interconnected world.DesignWe conducted an integrative review to examine ethical considerations in development of ethical global health experiences that benefit, rather than harm, host communities and participating nursing student guests.MethodsThe search included articles published in English language, peer-reviewed journals between 1998 and 2021 that discussed ethics in the context of nursing students traveling internationally for global health experiences. Eighteen articles met criteria for review.ResultsOverall, findings demonstrate relatively little research specific to ethical engagement in global health experiences. The articles in this integrative review discussed a range of ethical attributes including reciprocity or collaboration, respect, sustainability or commitment, justice and openness. Recommendations based on research and non-research articles are provided.ConclusionsEthical comportment in global health experiences requires careful planning, implementation and evaluation to assure an equitable and sustainable partnership between host community, faculty and nursing student guests.  相似文献   
3.
ObjectivesGuidelines suggest aortic valve replacement (AVR) for low-risk asymptomatic patients. Indications for transcatheter AVR now include low-risk patients, making it imperative to understand state-of-the-art surgical AVR (SAVR) in this population. Therefore, we compared SAVR outcomes in low-risk patients with those expected from Society of Thoracic Surgeons (STS) models and assessed their intermediate-term survival.MethodsFrom January 2005 to January 2017, 3493 isolated SAVRs were performed in 3474 patients with STS predicted risk of mortality <4%. Observed operative mortality and composite major morbidity or mortality were compared with STS-expected outcomes according to calendar year of surgery. Logistic regression analysis was used to identify risk factors for these outcomes. Patients were followed for time-related mortality.ResultsWith 15 observed operative deaths (0.43%) compared with 55 expected (1.6%), the observed:expected ratio was 0.27 for mortality (95% confidence interval [CI], 0.14-0.42), stroke 0.65 (95% CI, 0.41-0.89), and reoperation 0.50 (95% CI, 0.42-0.60). Major morbidity or mortality steadily declined, with probabilities of 8.6%, 6.7%, and 5.2% in 2006, 2011, and 2016, respectively, while STS-expected risk remained at approximately 12%. Mitral valve regurgitation, ventricular hypertrophy, pulmonary, renal, and hepatic failure, coronary artery disease, and earlier surgery date were residual risk factors. Survival was 98%, 91%, and 82% at 1, 5, and 9 years, respectively, superior to that predicted for the US age-race-sex–matched population.ConclusionsSTS risk models overestimate contemporary SAVR risk at a high-volume center, supporting efforts to create a more agile quality assessment program. SAVR in low-risk patients provides durable survival benefit, supporting early surgery and providing a benchmark for transcatheter AVR.  相似文献   
4.
BackgroundRecent guidelines for the treatment of moderate or severe ischemic mitral regurgitation (IMR) in patients undergoing coronary artery bypass grafting (CABG) have changed. This study assessed the real-world impact of changing guidelines on the management of IMR during CABG over time. We hypothesized that the utilization of mitral valve repair for IMR would decrease over time, whereas mitral valve replacement for severe IMR would increase.MethodsPatients undergoing CABG in a statewide collaborative database (2011-2020) were stratified by severity of IMR. Trends in mitral valve repair or replacement were evaluated. To account for differences of the patients, propensity score–matched analyses were used to compare patients with and without mitral intervention.ResultsA total of 11,676 patients met inclusion criteria, including 1355 (11.6%) with moderate IMR and 390 (3.3%) with severe IMR. The proportion of patients undergoing mitral intervention for moderate IMR decreased over time (2011, 17.7%; 2020, 7.5%; Ptrend = .001), whereas mitral replacement for severe IMR remained stable (2011, 11.1%; 2020, 13.3%; Ptrend = .14). Major morbidity was higher for patients with moderate IMR who underwent mitral intervention (29.1% vs 19.9%; P = .005). In a propensity analysis of 249 well-matched pairs, there was no difference in major morbidity (29.3% with mitral intervention vs 23.7% without; P = .16) or operative mortality (1.2% vs 2.4%; P = .5).ConclusionsConsistent with recent guideline updates, patients with moderate IMR were less likely to undergo mitral repair. However, the rate of replacement for severe IMR did not change. Mitral intervention during CABG did not increase operative mortality or morbidity.  相似文献   
5.
【目的】 在媒体融合的背景下,探索高校科技期刊获得良性、可持续发展的业务流程再造方案。【方法】 通过问卷调查法和深度访谈法,对《中国有色金属学报》学术用户的实际需求进行诊断分析,并依据《中国有色金属学报》一年内的业务流程再造实践,总结和设计普适性较强的高校科技期刊业务流程再造方案。【结果】 《中国有色金属学报》在学术用户群体服务与管理、学术资源挖掘和利用、缩短出版周期和媒体融合等方面进行业务流程再造并取得了显著成效。【结论】 高校科技期刊要想谋求新的发展和突破,必须基于用户日益增长的学术需求进行业务拓展,同时基于技术和机制,与时俱进地进行业务流程再造。  相似文献   
6.
PurposeTo create a nonsurgical animal model of osteoarthritis (OA) to evaluate the effects of embolotherapy during geniculate artery embolization (GAE).Materials and MethodsFluoroscopy-guided injections of 700 mg of sodium monoiodoacetate were performed into the left stifle in 6 rams. Kinematic data were collected before and after induction. At 10 weeks after induction, Subjects 1 and 4–6 underwent magnetic resonance (MR) imaging with dynamic contrast enhancement (DCE) and Subjects 1, 3, and 4–6 underwent angiography with angiographic scoring to identify regions with greatest disease severity for superselective embolization (75–250-μm microspheres). Target vessel size was measured. At 24 weeks after angiography, DCE-MR imaging, angiography, and euthanasia were performed, and bilateral stifles were harvested. Medial/lateral tibial and femoral condylar, patellar, and synovial samples were cut, preserved, decalcified, and scored using the Osteoarthritis Research Society International criteria. The stifle and synovium Whole-Organ Magnetic Resonance Imaging Score and Multicenter Osteoarthritis Study score were determined. The volume transfer constant (Ktrans) and extracellular volume fraction (ve) were calculated from DCE-MR imaging along the lateral synovial regions of interest.ResultsThe mean gross and microscopic pathological scores were elevated at 38 and 61, respectively. Mean synovitis score was elevated at 9.2. Mean pre-embolization and postembolization angiographic scores were 5 and 3.8, respectively. Mean superior, transverse, and inferior geniculate artery diameters were 3.1 mm ± 1.21, 2.0 mm ± 0.50, and 1.6 mm ± 0.41 mm, respectively. Mean pre-embolization and postembolization cartilage and synovitis scores were elevated at 35.13 and 73.3 and 5.5 and 9.2, respectively. The Ktrans/ve values of Subjects 4, 5, and 6 were elevated at 0.049/0.38, 0.074/0.53, and 0.065/0.51, respectively. Altered gait of the hind limb was observed in all subjects after induction, with reduced joint mobility. No skin necrosis or osteonecrosis was observed.ConclusionsA nonsurgical ovine animal knee OA model was created, which allowed the collection of angiographic, histopathological, MR imaging, and kinematic data to study the effects of GAE.  相似文献   
7.
目的编制护士"互联网+护理服务"参与行为意愿量表,并进行信效度检验。方法以计划行为理论为框架,采用文献回顾、半结构式访谈法形成量表的条目池;通过专家咨询、项目分析对量表条目进行筛选,初步形成护士"互联网+护理服务"参与行为意愿量表。采用方便抽样法,于2020年10—12月选取江苏省6所医院(2所三级医院、2所二级医院、2所一级医院)的825名护士进行正式调查,检验问卷的信效度。结果护士"互联网+护理服务"参与行为意愿量表包括3个分量表(参与行为态度、主观行为规范、感知行为控制)、8个维度、17个条目。总量表的Cronbach'sα系数为0.927、重测信度系数为0.805。护士"互联网+护理服务"参与行为意愿与参与行为的相关系数为0.743(P<0.01)。因子分析提取出8个公因子,累积方差贡献率为72.33%。结论护士"互联网+护理服务"参与行为意愿量表具有较好的信效度,可用于护士"互联网+护理服务"参与行为意愿的评估。  相似文献   
8.
ObjectiveTo evaluate the impact of structured recommendations on follow-up completion for incidental lung nodules (ILNs).MethodsPatients with ILNs before and after implementation of structured Fleischner recommendations and electronic tracking were sampled randomly. The cohorts were compared for imaging follow-up. Multivariable logistic regression was used to assess appropriate follow-up and loss to follow-up, with independent variables including use of structured recommendations or tracking, age, sex, race, ethnicity, setting of the index test (inpatient, outpatient, emergency department), smoking history, and nodule features.ResultsIn all, 1,301 patients met final inclusion criteria, including 255 patients before and 1,046 patients after structured recommendations or tracking. Baseline differences were found in the pre- and postintervention groups, with smaller ILNs and younger age after implementing structured recommendations. Comparing pre- versus postintervention outcomes, 40.0% (100 of 250) versus 29.5% (309 of 1,046) of patients had no follow-up despite Fleischner indications for imaging (P = .002), and among the remaining patients, 56.6% (82 of 145) versus 75.0% (553 of 737) followed up on time (P < .001). Delayed follow-up was more frequent before intervention. Differences postintervention were mostly accounted for by nodules ≤8 mm in the outpatient setting (P < .001). In multivariable analysis, younger age, White race, outpatient setting, and larger nodule size showed significant association with appropriate follow-up completion (P < .015), but structured recommendations did not. Similar results applied for loss to follow-up.DiscussionConsistent use of structured reporting is likely key to mitigate selection bias when benchmarking rates of appropriate follow-up of ILN. Emergency department patients and inpatients are at high risk of missed or delayed follow-up despite structured recommendations.  相似文献   
9.
以“七麦数据”网站收录的中医移动医疗App作为研究对象,采用网络调查法和文献分析法,根据“七麦数据”对移动医疗App的分类,结合中医移动医疗App的信息服务内容和特点,将筛选出的中医移动医疗App划分为医疗健康类、中医养生类、知识传播类、全面综合类,并根据“七麦数据”网站中对各类中医移动医疗App的打分及累计下载量筛选出最具代表性的12款中医移动医疗App,从全面性、人性化、安全性、实用性4个一级指标和40个二级指标对其信息服务现状进行评价,指出当前中医移动医疗App信息服务存在的问题并提出建议。  相似文献   
10.
While children in general are usually seen as a societal priority, many children are disadvantaged by marginalization, with adverse effects on health and development. Following feasibility studies, the European Commission has now adopted a formal Child Guarantee of service access. This paper links the Feasibility Studies to other reports on the need to address marginalized and institutionalized children. The problems in identifying and quantifying such children are outlined, as are the challenges of planning for these groups of children and the difficulty of finding universal definitions and data. This European Union initiative is timely, given that around a quarter of European children are marginalized, while the effects of Covid-19 will add to this marginalization.  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