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   424455篇
  免费   31255篇
  国内免费   9735篇
耳鼻咽喉   4800篇
儿科学   10669篇
妇产科学   7471篇
基础医学   37460篇
口腔科学   11213篇
临床医学   46333篇
内科学   50678篇
皮肤病学   5711篇
神经病学   24839篇
特种医学   11044篇
外国民族医学   42篇
外科学   42587篇
综合类   63667篇
一般理论   32篇
预防医学   48258篇
眼科学   6298篇
药学   42003篇
  472篇
中国医学   34892篇
肿瘤学   16976篇
  2023年   6856篇
  2022年   10284篇
  2021年   16257篇
  2020年   16674篇
  2019年   21171篇
  2018年   18292篇
  2017年   16247篇
  2016年   13285篇
  2015年   12719篇
  2014年   26012篇
  2013年   27781篇
  2012年   24224篇
  2011年   26119篇
  2010年   20595篇
  2009年   19021篇
  2008年   18451篇
  2007年   18968篇
  2006年   16459篇
  2005年   14311篇
  2004年   11746篇
  2003年   10385篇
  2002年   8105篇
  2001年   7348篇
  2000年   6029篇
  1999年   5157篇
  1998年   4128篇
  1997年   3867篇
  1996年   3350篇
  1995年   3416篇
  1994年   3326篇
  1993年   2625篇
  1992年   2596篇
  1991年   2267篇
  1990年   1981篇
  1989年   1814篇
  1988年   1696篇
  1987年   1465篇
  1986年   1327篇
  1985年   4149篇
  1984年   5069篇
  1983年   3504篇
  1982年   3993篇
  1981年   3700篇
  1980年   3308篇
  1979年   3012篇
  1978年   2612篇
  1977年   1960篇
  1976年   2216篇
  1975年   1656篇
  1974年   1467篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
1.
2.
徐素琴  向邱 《全科护理》2022,20(1):73-76
目的:探讨项目管理在降低呼吸重症监护室(RICU)环境物品表面多重耐药菌检出率中的应用效果。方法:采用目的抽样方法,选取医院呼吸与危重症医学科RICU 17张编制床位、32处高频接触环境物品表面及42名工作人员为观察对象。2019年1月—2019年3月实施RICU常规管理,2019年4月—2019年6月实施项目管理。比较项目管理前后RICU各类别工作人员手卫生依从率、RICU环境物品表面清洁合格率及多重耐药菌检出率。结果:在项目管理后RICU各类别工作人员手卫生依从率均高于项目管理前(P<0.05);项目管理后RICU环境物品表面清洁合格率较项目管理前升高(P<0.05);项目管理后多重耐药菌(MDRO)病人床单位及病区办公区域环境物体表面的耐甲氧西林金黄色葡萄球菌(MRSA)和耐碳青霉烯鲍曼不动杆菌(CRAB)检出率均较项目管理前降低(P<0.05)。结论:项目管理可有效提高RICU各类别工作人员手卫生依从性及环境物品表面清洁合格率,降低RICU环境物品表面多重耐药菌检出率。  相似文献   
3.
IntroductionDetailed data on clinical characteristics in children with the omicron strain of SARS-COV-2 are limited.MethodsWe conducted a retrospective observational study of children with COVID-19 at the National Center for Child Health and Development to evaluate the clinical manifestations during and before the emergence of the omicron variant. Only symptomatic patients without underlying diseases were included. Participants were divided into two temporal groups: the “omicron era” (1/2022–2/2022) and the “pre-omicron era,” where the delta variant predominated (7/2021–11/2021). The patients were subclassified into an older vaccine-eligible group (aged 12–17 years), a younger vaccine-eligible group (aged 5–11 years), and a vaccine-ineligible group (aged 0–4 years).ResultsWe compared 113 patients in the omicron era with 106 in the pre-omicron era. Most patients in both eras had non-severe disease, and no patients required mechanical ventilation or died. Among patients aged 0–4 years, sore throat and hoarseness were more common during the omicron era than the pre-omicron era (11.1% vs. 0.0% and 11.1% vs. 1.5%, respectively). Croup syndrome was diagnosed in all patients with hoarseness. Among patients aged 5–11 years, vomiting was more frequent during the omicron era (47.2%) than during the pre-omicron era (21.7%). Cough and rhinorrhea were less common during the omicron era in patients aged 0–4 and 5–11 years, respectively, than during the pre-omicron era.ConclusionsIn children with COVID-19, clinical manifestations differed between the omicron and pre-omicron eras. In the Omicron era, croup syndrome was more frequent in vaccine-ineligible children.  相似文献   
4.
The discussion paper will focus on continuity of care relating to previous NZ research, specifically to transitioning complex preterm infants from NICU to home based on parent experiences, and on the practice developments that have occurred, to ensure optimal health outcomes. Previous NZ research discovered parent desire a consistent service delivery for the entire transition journey from NICU and at home.An informative and comprehensive opportunity has occurred for reflective professional practice, evaluation, development and implementation which have transpired in positive change through innovative practice developments and support change implementation in Wellington, NZ. This has resulted in the articulation of a model of care that has both embraced and integrated parental desires for a continuity of care process for complex preterm infants. This has been achieved by having the same Discharge Facilitator/Key Case Manager present within the NICU and external to the NICU for Home-based infants for the entire transition journey.The paper will focus and emphasis additional practice development changes and furthermore, will present a real purpose, for other countries to learn of such practice developments that have exemplified a celebratory success for families of Wellington, NZ.  相似文献   
5.
6.
7.
8.
IntroductionThe aim of this study was to compare long-term patient reported outcomes (PROs) in patients with locally advanced extremity soft tissue sarcoma (eSTS) after isolated limb perfusion followed by resection (IR), compared to extended resection (ER), primary amputation (A) or secondary amputation after IR (IR-A).MethodsPatients were selected from the respondents of a multi-institutional cross-sectional cohort survivorship study (SURVSARC) conducted among sarcoma survivors registered in the Netherlands Cancer Registry (NCR), 2–10 years after diagnosis. Used PROs were the EORTC QLQ-C30, the Cancer worry scale (CWS), the Hospital Anxiety and Depression Scale (HADS), and the Toronto Extremity Salvage Score (TESS).ResultsWe identified 97 eSTS survivors: IR = 20, ER = 49, A = 20, IR-A = 8. While there were no differences in PROs between IR and ER, results showed better functioning and functionality in both groups versus the amputation groups. The amputation groups scored significantly lower on physical functioning (A = 62.7, IR-A = 65.7 versus IR = 78.0, ER = 82.7, p = 0.001) and role functioning (A = 67.5, IR-A = 52.8 versus IR = 79.2, ER = 80.6, p = 0.039), both EORTC QLQ-C30 scales. Also for the TESS, the scores were significantly lower for the amputation groups compared to the limb sparing groups (upper extremity p = 0.007 with A = 68.9, IR-A = 71.6 versus IR = 93.3, ER = 91.1; lower extremity p < 0.001 with A = 72.2, IR-A50.9 versus IR = 84.5 and ER = 85.5). There were no significant differences between the groups on cancer worry, anxiety and depression.ConclusionHRQoL in eSTS survivors treated with IR or ER is equal; for maintenance of physical functioning and functionality IR and ER outperform an amputation.  相似文献   
9.
10.
《Dental materials》2022,38(1):204-213
ObjectiveTo investigate the fatigue behavior of restored teeth, in particular the mechanisms of longitudinal dentinal cracking under cyclic mechanical loading, using finite element analysis (FEA) and the stress-life (S-N) approach.MethodsTen root-filled premolars restored with resin composites were subjected to step-stress cyclic loading to produce longitudinal cracks. Fracture loads and number of cycles completed at each load level were recorded. FEA was used to predict the stress amplitude of each component under the global cyclic load. Both intact and debonded conditions were considered for the dentin-composite interface in the FEA. The predicted stress concentrations were compared with the fracture patterns to help elucidate the failure mechanisms. The S-N approach was further used to predict the lifetimes of the different components in the restored teeth. Cumulative fatigue damage was represented by the sum of the fractions of life spent under the different stress amplitudes.ResultsLongitudinal cracks were seen in ~50% of the samples with a mean fracture load of 770 ± 45 N and a mean number of cycles to failure of 32,297 ± 12,624. The longitudinal dentinal cracks seemed to start near the line angle of the cavity, and propagated longitudinally towards the root. The sum of fractions of life spent for the dentin-composite interface exceeded 1 after ~7000 cycles when that for dentin was much lower than 1, indicating that interfacial debonding would occur prior to dentin fracture. This was supported by micro-CT images showing widened interfacial space in the cracked samples. In the debonded tooth, FEA showed dentinal stress concentrations at the gingival wall of the cavity, which coincided with the longitudinal cracks found in the cyclic loading test. The sum of fractions of life spent for dentin was close to 1 at ~30,000 cycles, similar to the experimental value.SignificanceDebonding of the dentin-composite interface may occur prior to longitudinal cracking of dentin in root-filled teeth under cyclic loading. The approximate time of occurrence for these events could be estimated using fatigue analysis with stresses provided by FEA. This methodology can therefore be used to evaluate the longevity of restoration designs for root-filled teeth.  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