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   403312篇
  免费   32420篇
  国内免费   8962篇
耳鼻咽喉   4521篇
儿科学   7195篇
妇产科学   6535篇
基础医学   39878篇
口腔科学   10373篇
临床医学   36920篇
内科学   55116篇
皮肤病学   4477篇
神经病学   21976篇
特种医学   12812篇
外国民族医学   13篇
外科学   35688篇
综合类   59577篇
现状与发展   29篇
一般理论   30篇
预防医学   41250篇
眼科学   4285篇
药学   45221篇
  390篇
中国医学   37321篇
肿瘤学   21087篇
  2024年   888篇
  2023年   6515篇
  2022年   10606篇
  2021年   18209篇
  2020年   16529篇
  2019年   17769篇
  2018年   16551篇
  2017年   15474篇
  2016年   14536篇
  2015年   13813篇
  2014年   22612篇
  2013年   26406篇
  2012年   22216篇
  2011年   25036篇
  2010年   18472篇
  2009年   17076篇
  2008年   18010篇
  2007年   19079篇
  2006年   17099篇
  2005年   15363篇
  2004年   12927篇
  2003年   11512篇
  2002年   9068篇
  2001年   8023篇
  2000年   6848篇
  1999年   5846篇
  1998年   4656篇
  1997年   4644篇
  1996年   3996篇
  1995年   3616篇
  1994年   3406篇
  1993年   2899篇
  1992年   2693篇
  1991年   2531篇
  1990年   2166篇
  1989年   1849篇
  1988年   1780篇
  1987年   1606篇
  1986年   1495篇
  1985年   3046篇
  1984年   3084篇
  1983年   2080篇
  1982年   2504篇
  1981年   1824篇
  1980年   1635篇
  1979年   1394篇
  1978年   1058篇
  1977年   806篇
  1976年   949篇
  1975年   660篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.

Background and objective

Pressure ulcer (PU) is one of the important and frequent complications of hospitalization, associated with high treatment costs. The present study was conducted to determine the incidence of PU and its direct treatment costs for patients in intensive care unit (ICU) in Iran.

Material and methods

In this retrospective study, medical records of 643 discharged patients from ICU of two selected hospitals were examined. The demographic and clinical data of all patients and data of resources and services usage for patients with PU were extracted through their records. Data analysis was done using logistic regression tests in SPSS 22 software. The cost of PU treatment was calculated for each grade of ulcer.

Results

The findings showed that 8.9% of patients developed PU during their stay in ICU. Muscular paralysis (OR?=?5.1), length of stay in ICU (OR?=?4.0), diabetes (OR?=?3.5) age (OR?=?2.9), smoking (OR?=?2.1) and trauma (OR?=?1.4) were the most important risk factors of PU. The average cost of PU treatment varied from USD 12 for grade I PU to USD 66?834 for grade IV PUs. The total treatment costs for all studied patients with PU was estimated at USD 519?991.

Conclusion

The cost of PU treatment is significant. Since the preventive measures are more cost-effective than therapeutic measures, therefore, effective preventive interventions are recommended.  相似文献   
86.
87.
88.
目的探讨中西医结合护理改善老年高血压患者心理状态及生活质量的效果。方法在医院2018年1月—2018年6月就诊的老年高血压患者中选出60例,按照随机数字法的原则,分成研究组(n=30)和参考组(n=30)。参考组采用单一西医护理,研究组在此之外联合中医护理,比较两组患者的临床疗效。结果入院时研究组与参考组SAS、SDS、SF-6评分差异不显著(P>0.05),护理后1月、3月与参考组相比,研究组SAS、SDS评分显著降低(P<0.05),SF-6评分显著升高(P<0.05);研究组患者对中西结合护理满意度为96.67%,参考组患者对西医护理满意度为73.33%,研究组满意度较参考组高,差异显著(P<0.05)。结论中西医结合护理能够有效改善老年高血压患者的心理状态,提高生活质量。  相似文献   
89.
《Vaccine》2016,34(51):6626-6633
BackgroundSafety signal detection in spontaneous reporting system databases and electronic healthcare records is key to detection of previously unknown adverse events following immunization. Various statistical methods for signal detection in these different datasources have been developed, however none are geared to the pediatric population and none specifically to vaccines. A reference set comprising pediatric vaccine-adverse event pairs is required for reliable performance testing of statistical methods within and across data sources.MethodsThe study was conducted within the context of the Global Research in Paediatrics (GRiP) project, as part of the seventh framework programme (FP7) of the European Commission. Criteria for the selection of vaccines considered in the reference set were routine and global use in the pediatric population. Adverse events were primarily selected based on importance. Outcome based systematic literature searches were performed for all identified vaccine-adverse event pairs and complemented by expert committee reports, evidence based decision support systems (e.g. Micromedex), and summaries of product characteristics. Classification into positive (PC) and negative control (NC) pairs was performed by two independent reviewers according to a pre-defined algorithm and discussed for consensus in case of disagreement.ResultsWe selected 13 vaccines and 14 adverse events to be included in the reference set. From a total of 182 vaccine-adverse event pairs, we classified 18 as PC, 113 as NC and 51 as unclassifiable. Most classifications (91) were based on literature review, 45 were based on expert committee reports, and for 46 vaccine-adverse event pairs, an underlying pathomechanism was not plausible classifying the association as NC.ConclusionA reference set of vaccine-adverse event pairs was developed. We propose its use for comparing signal detection methods and systems in the pediatric population.  相似文献   
90.
David Marr's three-level method for completely understanding a cognitive system and the importance he attaches to the computational level are so familiar as to scarcely need repeating. Fewer seem to recognize that Marr defends his famous method by criticizing the “reductionistic approach.” This sets up a more interesting relationship between Marr and reductionism than is usually acknowledged. I argue that Marr was correct in his criticism of the reductionists of his time—they were only describing (cellular activity), not explaining (cognitive functions). But a careful metascientific account of reductionistic neuroscience over the past two decades reveals that Marr's criticisms no longer have force. Contemporary neuroscience now explains cognition directly, although in a fashion—causal-mechanistically—quite different than Marr recommended. So while Marr was correct to reject the reductionism of his day and offer an alternative method for genuinely explaining cognition, contemporary cognitive scientists now owe us a new defense of Marr's famous method and the advantages of its explanations over the type now pursued successfully in current reductionist neuroscience. There are familiar reasons for thinking that this debt will not be paid easily.  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