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   12984篇
  免费   882篇
  国内免费   39篇
耳鼻咽喉   86篇
儿科学   387篇
妇产科学   388篇
基础医学   1805篇
口腔科学   409篇
临床医学   1932篇
内科学   2209篇
皮肤病学   195篇
神经病学   1124篇
特种医学   319篇
外科学   1147篇
综合类   132篇
一般理论   14篇
预防医学   1856篇
眼科学   186篇
药学   866篇
  1篇
中国医学   22篇
肿瘤学   827篇
  2023年   74篇
  2022年   149篇
  2021年   305篇
  2020年   205篇
  2019年   280篇
  2018年   355篇
  2017年   241篇
  2016年   320篇
  2015年   350篇
  2014年   484篇
  2013年   686篇
  2012年   994篇
  2011年   1021篇
  2010年   604篇
  2009年   540篇
  2008年   910篇
  2007年   927篇
  2006年   877篇
  2005年   822篇
  2004年   739篇
  2003年   645篇
  2002年   626篇
  2001年   127篇
  2000年   107篇
  1999年   135篇
  1998年   119篇
  1997年   103篇
  1996年   76篇
  1995年   75篇
  1994年   59篇
  1993年   65篇
  1992年   69篇
  1991年   51篇
  1990年   48篇
  1989年   64篇
  1988年   60篇
  1987年   53篇
  1986年   43篇
  1985年   48篇
  1984年   55篇
  1983年   43篇
  1982年   33篇
  1981年   40篇
  1980年   40篇
  1979年   50篇
  1978年   26篇
  1977年   18篇
  1976年   13篇
  1974年   17篇
  1970年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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   

2.
Objective: The objective of this study was to gain greater insight into individuals’ quality of life (QOL) definitions, appraisals, and adaptations following spinal cord injury (SCI).

Design: A mixed-methods design, applying the Schwartz and Sprangers response shift (RS) model. RS is a cognitive process wherein, in response to a change in health status, individuals change internal standards, values, or conceptualization of QOL

Setting: Community-dwelling participants who receive medical treatment at a major Midwestern medical system and nearby Veterans’ Affairs hospital.

Participants: A purposive sample of participants with SCI (N?=?40) completed semi-structured interviews and accompanying quantitative measures.

Interventions: Not applicable.

Outcome Measures: Qualitative data were analyzed using content analysis to identify themes. Analysis of variance were performed to detect differences based on themes and QOL, well-being, and demographic and injury characteristics.

Results: Four RS themes were identified, capturing the range of participant perceptions of QOL. The themes ranged from complete RS, indicating active engagement in maintaining QOL, to awareness and comparisons redefining QOL, to a relative lack of RS. Average QOL ratings differed as a function of response shift themes. PROMIS Global Health, Anxiety, and Depression also differed as a function of RS themes.

Conclusion: The RS model contextualizes differences in QOL definitions, appraisals, and adaptations in a way standardized QOL measures alone do not.  相似文献   

3.
4.
Protein composition and mechanical function of intermediate filaments were examined in arteries of different sizes using desmin deficient mice (Des−/−) and their wild-type controls (Des+/+). Using SDS-PAGE gels and Western blots we found a gradient in desmin expression in the arterial tree; the desmin content increased from the elastic artery aorta, via the muscular mesenteric artery to the resistance-sized mesenteric microarteries ∼150 μm in diameter in Des+/+ mice. Mechanical experiments were performed on the aorta, the mesenteric artery and resistance-sized arteries using wire myographs. For aorta and mesenteric artery, no differences in passive or active circumference- stress relations were found between Des−/− and Des+/+ mice. In microarteries, both passive and active stress were lower in the Des−/− group. In conclusion, large elastic and muscular arteries contain a relatively low amount of desmin, and the desmin intermediate filaments do not seem to play a major role in the mechanical properties of these larger arterial vessels. In the microarteries, where expression of desmin is high, desmin plays a role in supporting both passive and active tension.  相似文献   
5.
PURPOSE: The Rodenstock scanning laser ophthalmoscope (SLO) is useful for mapping retinal function and for developing and evaluating visual rehabilitation methods. It is essential to know the visual angle subtended by stimuli in the SLO laser-beam raster and to accurately measure angular distances between objects in the final SLO image. To accomplish this, the angular extent of the SLO laser-beam raster must be calibrated. METHODS: We developed a simple method and apparatus for calibrating the raster and used it for repeated calibrations during a 3-month period. RESULTS: The laser-beam raster is quite stable in shape and size, but it is trapezoidally distorted in the vertical direction. Consequently, SLO images are distorted. CONCLUSIONS: Trapezoidal distortion of the SLO laser-beam raster can cause stimulus size to change as much as 10% from the top to the bottom of the raster. Measurements of fixed horizontal retinal landmark distances in SLO images can also vary as much as 10%. We developed a straightforward mathematical method for correcting distortion in SLO image measurements.  相似文献   
6.
7.
8.
Previous work has reported that the 5-hydroxytryptamine (5-HT)1A agonist, 8-hydroxy 2-(di-n-propylamino)tetralin (8-OH DPAT), reduces ethanol intake by rats. However, as 8-OH DPAT reduces 5-HT neurotransmission, these findings are inconsistent with the proposed inhibitory role of central 5-HT neurons on ethanol intake. We examined the effect of 8-OH DPAT on ethanol, water and food intake in rats maintained on a limited access schedule using a lower dose range (6–250 µg/kg) and by assessing concomitant changes in behaviour. Low doses of 8-OH DPAT enhanced ethanol intake even when food and water were offered as alternatives. Suppression in ethanol intake was observed at higher doses where elements of the 5-HT syndrome were apparent. Similar observations were made in both fluid and non-fluid deprived water drinking rats, suggesting the latter effect is non-selective. Therefore 8-OH DPAT may both increase or decrease ethanol consumption in the rat depending on the dose used.  相似文献   
9.
The relationship between dietary fat intake and fasting plasma lipid levels was assessed in 35 female and 19 male adolescents recruited from two local education authority schools in Norwich, UK. Dietary intakes were assessed using a 7-day weighed dietary record method, coupled with the collection of duplicate diets. Fat and energy intakes calculated using food composition tables were compared with values obtained by direct analysis of duplicate diets. Fasting plasma lipid levels (total, HDL and LDL cholesterol and triglycerides) were measured and compared with total dietary lipids and fatty acid intakes. The average proportion of energy consumed as fat was higher than is currently considered desirable but lower than previous studies have reported for adults. Mean serum total cholesterol values were 4.2 (SEM 0.1) mmol for females and 4.5 (SEM 0.2) mmol for males; this difference was not statistically significant. In male subjects the dietary fatty acid profiles were significantly correlated with several parameters of plasma lipid status which are thought to be risk factors for coronary heart disease, and in particular with the ratio of total:HDL cholesterol.  相似文献   
10.
We examined the possible unintended consequences of a 72-hour automatic order to discontinue vancomycin therapy in an antimicrobial stewardship program (ASP). Of 120 patients, 11 had vancomycin therapy discontinued at 72 hours without a call to the ASP, and 7 experienced a treatment interruption of 6-36 hours. All discontinuation of therapy was considered appropriate, and the 7 treatment interruptions did not have clear clinical consequences. Only one-third of patients had ASP stickers that warned of impending discontinuation of vancomycin therapy placed appropriately in the medical record.  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