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   9214篇
  免费   881篇
  国内免费   127篇
耳鼻咽喉   34篇
儿科学   76篇
妇产科学   65篇
基础医学   2097篇
口腔科学   64篇
临床医学   917篇
内科学   1974篇
皮肤病学   99篇
神经病学   1224篇
特种医学   1015篇
外科学   476篇
综合类   411篇
预防医学   1017篇
眼科学   120篇
药学   322篇
  11篇
中国医学   46篇
肿瘤学   254篇
  2024年   18篇
  2023年   164篇
  2022年   207篇
  2021年   343篇
  2020年   403篇
  2019年   407篇
  2018年   312篇
  2017年   305篇
  2016年   283篇
  2015年   320篇
  2014年   451篇
  2013年   503篇
  2012年   347篇
  2011年   367篇
  2010年   350篇
  2009年   395篇
  2008年   438篇
  2007年   394篇
  2006年   408篇
  2005年   328篇
  2004年   344篇
  2003年   282篇
  2002年   304篇
  2001年   354篇
  2000年   204篇
  1999年   180篇
  1998年   197篇
  1997年   229篇
  1996年   179篇
  1995年   185篇
  1994年   144篇
  1993年   153篇
  1992年   90篇
  1991年   84篇
  1990年   80篇
  1989年   59篇
  1988年   52篇
  1987年   52篇
  1986年   47篇
  1985年   56篇
  1984年   64篇
  1983年   29篇
  1982年   23篇
  1981年   29篇
  1980年   21篇
  1979年   24篇
  1978年   7篇
  1977年   4篇
  1975年   1篇
  1966年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
ContextPalliative care is gaining ground globally and is endorsed in high-level policy commitments, but service provision, supporting policies, education, and funding are incommensurate with rapidly growing needs.ObjectivesThe objective of this study was to describe current levels of global palliative care development and report on changes since 2006.MethodsAn online survey of experts in 198 countries generated 2017 data on 10 indicators of palliative care provision, fitted to six categories of development. Factor analysis and discriminant analysis showed the validity of the categorization. Spearman correlation analyses assessed the relationship with World Bank Income Level (WBIL), Human Development Index (HDI), and Universal Health Coverage (UHC).ResultsNumbers (percentages) of countries in each development category were as follows: 1) no known palliative care activity, 47 (24%); 2) capacity-building, 13 (7%); 3a) isolated provision, 65 (33%); 3b) generalized provision, 22 (11%); 4a) preliminary integration into mainstream provision, 21 (11%); 4b) advanced integration, 30 (15%). Development levels were significantly associated with WBIL (rS = 0.4785), UHC (rS = 0.5558), and HDI (rS = 0.5426) with P < 0.001. Net improvement between 2006 and 2017 saw 32 fewer countries in Categories 1/2, 16 more countries in 3a/3b, and 17 more countries in 4a/4b.ConclusionPalliative care at the highest level of provision is available for only 14% of the global population and is concentrated in European countries. An 87% global increase in serious health-related suffering amenable to palliative care interventions is predicted by 2060. With an increasing need, palliative care is not reaching the levels required by at least half of the global population.  相似文献   
6.
目的 探讨思维导图在本科护生精神科实习带教中的应用效果。方法 选取2018年6月至12月31名本科护生为试验组,采用思维导图进行带教;选取2019年4月至7月32名本科护生作为对照组,采用传统的带教方法进行带教。比较两组前后评判性思维能力、对带教方法的评价,以及两组护生的理论、操作考试成绩。采用SPSS 20.0进行t检验、卡方检验和秩和检验。结果 试验组在评判性思维能力量表各项得分明显提高,由带教前的(248.09±24.45)分提高至(331.03±14.31)分,且高于对照组(P<0.05)。试验组在带教方法肯定性评价各项得分均高于对照组,差异均有统计学意义(P<0.05)。试验组带教后理论成绩为(88.35±7.71)分、操作考试成绩为(86.45±5.03)分,对照组带教后理论成绩为(74.41±10.27)分、操作考试成绩为(81.02±6.64)分,两组比较差异有统计学意义(P<0.05)。结论 运用思维导图对精神科护生进行临床带教,提高了护生学习积极性,学习由被动变主动,同时促进了护生评判性思维能力培养,值得临床推广。  相似文献   
7.
目的探讨PBL与思维导图相结合教学模式在临床教学中的应用。方法本文研究对象为在我院见习的临床本科生,为大理大学2015级一个班级,共55名学生,数据收集时间为2019年1月;按照授课方式的差异将学生分为实验班与对照班,实验班27名学生,对照班28名学生;对照班实施常规教学法,实验班实施PBL与思维导图相结合教学法。结果实验班教学结束测试得分为(85.60±3.46)分,对照班教学结束测试得分为(77.48±3.12)分,差异具有统计学意义(P<0.05);实验班教学方式满意度评分为(90.35±4.12)分,对照班教学方式满意度评分为(80.25±4.05)分,差异具有统计学意义(P<0.05)。结论在临床教学中采用PBL与思维导图相结合教学模式,能够提高学生的专业知识掌握水平与对教学模式的认可度。  相似文献   
8.
《Clinical neurophysiology》2020,131(5):1087-1098
ObjectiveFunctional connectivity networks (FCNs) based on interictal electroencephalography (EEG) can identify pathological brain networks associated with epilepsy. FCNs are altered by interictal epileptiform discharges (IEDs), but it is unknown whether this is due to the morphology of the IED or the underlying pathological activity. Therefore, we characterized the impact of IEDs on the FCN through simulations and EEG analysis.MethodsWe introduced simulated IEDs to sleep EEG recordings of eight healthy controls and analyzed the effect of IED amplitude and rate on the FCN. We then generated FCNs based on epochs with and without IEDs and compared them to the analogous FCNs from eight subjects with infantile spasms (IS), based on 1340 visually marked IEDs. Differences in network structure and strength were assessed.ResultsIEDs in IS subjects caused increased connectivity strength but no change in network structure. In controls, simulated IEDs with physiological amplitudes and rates did not alter network strength or structure.ConclusionsIncreases in connectivity strength in IS subjects are not artifacts caused by the interictal spike waveform and may be related to the underlying pathophysiology of IS.SignificanceDynamic changes in EEG-based FCNs during IEDs may be valuable for identification of pathological networks associated with epilepsy.  相似文献   
9.
Background: Accurate measurement of the QT interval is important for diagnosing long QT syndrome (LQTS), and in research on determinants of ventricular repolarization time. We tested automatic analysis of QT intervals from multiple ECG leads on chest. Methods: Eleven healthy volunteers and 10 genotyped LQTS patients were tested at rest and during exercise with a bicycle ergometer twice 1–31 months apart. Electrocardiograms were recorded with the body surface potential mapping system, and 12 precordial channels were selected for analysis. Averaged QT peak and QT end intervals were determined with an automated algorithm, and the difference QT end minus QT peak (Tp‐e) was calculated. Repeatability was assessed by coefficient of variation (CV) between measurements. Results: Within one test at rest the QT end intervals were highly repeatable with CV 0.6%. In repeated tests CV was 4.4% for QT end interval and 3.5% when the QT interval was corrected for heart rate. In exercise test at specified heart rates, mean CV was 3.0% for QT end and 2.9% for QT peak interval. The CV of Tp‐e interval was 10.2% at rest, and 9.3% in exercise test. Reproducibility was comparable between healthy subjects and LQTS patients. Conclusions: The BSPM system with automated analysis produced accurate and highly repeatable QT interval measurements. Reproducibility was adequate also over prolonged time periods both at rest and in exercise stress test. The method can be applied in studying duration of ventricular repolarization time in different physiologic and pharmacologic interventions.  相似文献   
10.
Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight.  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