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   1391169篇
  免费   91374篇
  国内免费   1781篇
耳鼻咽喉   18825篇
儿科学   39321篇
妇产科学   34507篇
基础医学   212045篇
口腔科学   39205篇
临床医学   122555篇
内科学   265513篇
皮肤病学   29724篇
神经病学   101842篇
特种医学   54241篇
外国民族医学   130篇
外科学   220348篇
综合类   24834篇
现状与发展   2篇
一般理论   332篇
预防医学   95817篇
眼科学   31835篇
药学   108082篇
  4篇
中国医学   3136篇
肿瘤学   82026篇
  2018年   13803篇
  2017年   10455篇
  2016年   11804篇
  2015年   13333篇
  2014年   18118篇
  2013年   26645篇
  2012年   37479篇
  2011年   40082篇
  2010年   23505篇
  2009年   21940篇
  2008年   38218篇
  2007年   40822篇
  2006年   41166篇
  2005年   39452篇
  2004年   38311篇
  2003年   36887篇
  2002年   36009篇
  2001年   73273篇
  2000年   75591篇
  1999年   62778篇
  1998年   15242篇
  1997年   13254篇
  1996年   13333篇
  1995年   12476篇
  1994年   11394篇
  1993年   10679篇
  1992年   47700篇
  1991年   47358篇
  1990年   46325篇
  1989年   45219篇
  1988年   41334篇
  1987年   40545篇
  1986年   37729篇
  1985年   36109篇
  1984年   26051篇
  1983年   22151篇
  1982年   11439篇
  1979年   23697篇
  1978年   16242篇
  1977年   13602篇
  1976年   12774篇
  1975年   14605篇
  1974年   17157篇
  1973年   16282篇
  1972年   15337篇
  1971年   14595篇
  1970年   13807篇
  1969年   12904篇
  1968年   11950篇
  1967年   10726篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Objectives: The steeling effect suggests that early-life adversity can have a beneficial impact later in life. However, little is known about its underlying mechanisms and long-term outcomes . The study aimed to examine the role of early-life adversity (ELA) on successful aging, and whether this relationship can be explained by mental and physical health.

Method: Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (Mage = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted.

Results: Significant inverse U-shaped associations were found between ELA and iQoL (β = ?.59, p = .005) and between ELA and mental health (β = ?.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = ?.84, BCa CI [?1.66, ?.27]).

Conclusion: Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity.  相似文献   

93.

Background

Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.

Methods

A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.

Results

The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).

Conclusion

Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.

Level of Evidence

Therapeutic Level IV.  相似文献   
94.
At this study a multi-criteria model was developed to examine the available procedures, techniques and methods of handling infectious waste in the large healthcare unit of University Regional General Hospital of Patras, Western Greece. Particularly, this study examined the: a) current legislation and Directives issued for medical waste management at Greece and among the other EU-members, b) contribution of healthcare wastes (HCW) generation rate on social and economic parameters in selected European countries, c) available procedures, techniques, and methods upon the disposal of infectious wastes at the healthcare studied, and, d) propositions for integrated management of such hazardous wastes. Specifically, the Analytic Hierarchy Process (AHP) methodology was applied under pair wise comparison matrices in two stages: 1) the scale factors and the indicators, and 2) the criteria and their sub–criteria. The assessment of these pair wise matrices included the indicators and the sub–criteria. Subsequently, two pair wise comparison matrices, upon a) the “Fulfillment of environmental objectives” indicator and b) the “Energy consumption” sub criterion, were denoted. The AHP methodology yielded good results; however there is still space of improving the environmental performance. The normalized relative weights obtained for the criteria and sub criteria motivated specific actions that have to be handled. Particularly, the results indicated a very good value in environmental management criteria due the values obtained for the commitment towards the environmental policy standards and the waste management procedures. However, further improvements on staff awareness (such as development programs to enhance sensitivity) and more green purchasing suppliers, should be further addressed.  相似文献   
95.
Hillermann  T.  Homburg  K.  Rainer  M.  Budde  U. 《Der Anaesthesist》2022,71(4):299-302
Die Anaesthesiologie - Eine junge Patientin erleidet während der Anlage einer axillären Plexusblockade einen generalisierten Krampfanfall. Die Mechanismen, im Wesentlichen die vermutlich...  相似文献   
96.
97.
98.
Neuroscience and Behavioral Physiology - Objective. To determine the frequency, structure, and severity of cognitive impairments in patients with bipolar affective disorder (BAD) in remission....  相似文献   
99.
100.
Donor site morbidity following radial forearm flap (RFF) harvest remains a controversial issue. The aim of this meta-analysis was to answer the question “Are the range of wrist movements (range of motion, ROM) and hand strength affected after RFF harvesting?” The PubMed, Embase, Scopus, and Cochrane Library electronic databases were systematically searched (to December 2019). Self-controlled studies evaluating hand biomechanics after RFF harvest were included. Weighted mean differences with 95% confidence intervals were calculated using the random-effects model. The outcome variables were ROM, forearm movements, grip, and pinch strengths. Thirteen studies involving a total of 335 patients were included. With the exception of grip strength and supination, which showed statistically significant reductions of about 2.40 kg and 2.86° (P < 0.05), all other ROM, forearm movements, and pinch strengths showed an insignificant difference when the operated hand was compared to the non-operated hand (P > 0.05). Regression analysis showed that the method of donor site closure and size of the donor site defect had an insignificant impact on hand biomechanics. This study confirms the lack of discernible biomechanical morbidity after RFF transfer. The minimal reduction in hand biomechanics after RFF is considered to be clinically negligible.  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