全文获取类型
| 收费全文 | 1708442篇 |
| 免费 | 108756篇 |
| 国内免费 | 3589篇 |
专业分类
| 耳鼻咽喉 | 23027篇 |
| 儿科学 | 51997篇 |
| 妇产科学 | 45779篇 |
| 基础医学 | 231954篇 |
| 口腔科学 | 45667篇 |
| 临床医学 | 143122篇 |
| 内科学 | 333925篇 |
| 皮肤病学 | 33485篇 |
| 神经病学 | 140819篇 |
| 特种医学 | 68775篇 |
| 外国民族医学 | 448篇 |
| 外科学 | 268328篇 |
| 综合类 | 36815篇 |
| 现状与发展 | 8篇 |
| 一般理论 | 714篇 |
| 预防医学 | 127639篇 |
| 眼科学 | 37928篇 |
| 药学 | 123471篇 |
| 5篇 | |
| 中国医学 | 3906篇 |
| 肿瘤学 | 102975篇 |
出版年
| 2018年 | 37621篇 |
| 2017年 | 30223篇 |
| 2016年 | 34213篇 |
| 2015年 | 16443篇 |
| 2014年 | 22902篇 |
| 2013年 | 33933篇 |
| 2012年 | 51281篇 |
| 2011年 | 68463篇 |
| 2010年 | 46410篇 |
| 2009年 | 38484篇 |
| 2008年 | 66039篇 |
| 2007年 | 73046篇 |
| 2006年 | 50024篇 |
| 2005年 | 51536篇 |
| 2004年 | 51479篇 |
| 2003年 | 51170篇 |
| 2002年 | 48098篇 |
| 2001年 | 65850篇 |
| 2000年 | 67461篇 |
| 1999年 | 57498篇 |
| 1998年 | 17385篇 |
| 1997年 | 15911篇 |
| 1996年 | 15101篇 |
| 1995年 | 14127篇 |
| 1994年 | 13210篇 |
| 1993年 | 12246篇 |
| 1992年 | 44030篇 |
| 1991年 | 42513篇 |
| 1990年 | 41717篇 |
| 1989年 | 40571篇 |
| 1988年 | 38025篇 |
| 1987年 | 37459篇 |
| 1986年 | 35926篇 |
| 1985年 | 34226篇 |
| 1984年 | 26212篇 |
| 1983年 | 22388篇 |
| 1982年 | 14348篇 |
| 1981年 | 12989篇 |
| 1979年 | 24709篇 |
| 1978年 | 17948篇 |
| 1977年 | 15683篇 |
| 1976年 | 14185篇 |
| 1975年 | 15871篇 |
| 1974年 | 18725篇 |
| 1973年 | 18099篇 |
| 1972年 | 17218篇 |
| 1971年 | 16032篇 |
| 1970年 | 15251篇 |
| 1969年 | 14604篇 |
| 1968年 | 13674篇 |
排序方式： 共有10000条查询结果，搜索用时 0 毫秒
1.
2.
3.
4.
5.
6.
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
7.
Clint R. Bellenger John B. Arnold Jonathan D. Buckley Dominic Thewlis Joel T. Fuller 《Journal of Science and Medicine in Sport》2019,22(3):294-299
Objectives
To investigate whether functional overreaching affects locomotor system behaviour when running at fixed relative intensities and if any effects were associated with changes in running performance.Design
Prospective intervention study.Methods
Ten trained male runners completed three training blocks in a fixed order. Training consisted of one week of light training (baseline), two weeks of heavy training designed to induce functional overreaching, and ten days of light taper training designed to allow athletes to recover from, and adapt to, the heavy training. Locomotor behaviour, 5-km time trial performance, and subjective reports of training status (Daily Analysis of Life Demands for Athletes (DALDA) questionnaire) were assessed at the completion of each training block. Locomotor behaviour was assessed using detrended fluctuation analysis of stride intervals during running at speeds corresponding to 65% and 85% of maximum heart rate (HRmax) at baseline.Results
Time trial performance (effect size ±95% confidence interval (ES): 0.16 ± 0.06; p < 0.001), locomotor behaviour at 65% HRmax (ES: ?1.12 ± 0.95; p = 0.026), and DALDA (ES: 2.55 ± 0.80; p < 0.001) were all detrimentally affected by the heavy training. Time trial performance improved relative to baseline after the taper (ES: ?0.16 ± 0.10; p = 0.003) but locomotor behaviour at 65% HRmax (ES: ?1.18 ± 1.17; p = 0.048) and DALDA (ES: 0.92 ± 0.90; p = 0.045) remained impaired.Conclusions
Locomotor behaviour during running at 65% HRmax was impaired by functional overreaching and remained impaired after a 10-day taper, despite improved running performance. Locomotor changes may increase injury risk and should be considered within athlete monitoring programs independently of performance changes. 相似文献8.
Julia H. Vermylen Gordon J. Wood Elaine R. Cohen Jeffrey H. Barsuk William C. McGaghie Diane B. Wayne 《Journal of pain and symptom management》2019,57(3):682-687
Introduction
Physician communication impacts patient outcomes. However, communication skills, especially around difficult conversations, remain suboptimal, and there is no clear way to determine the validity of entrustment decisions. The aims of this study were to 1) describe the development of a simulation-based mastery learning (SBML) curriculum for breaking bad news (BBN) conversation skills and 2) set a defensible minimum passing standard (MPS) to ensure uniform skill acquisition among learners.Innovation
An SBML BBN curriculum was developed for fourth-year medical students. An assessment tool was created to evaluate the acquisition of skills involved in a BBN conversation. Pilot testing was completed to confirm improvement in skill acquisition and set the MPS.Outcomes
A BBN assessment tool containing a 15-item checklist and six scaled items was developed. Students' checklist performance improved significantly at post-test compared to baseline (mean 65.33%, SD = 12.09% vs mean 88.67%, SD = 9.45%, P < 0.001). Students were also significantly more likely to have at least a score of 4 (on a five-point scale) for the six scaled questions at post-test. The MPS was set at 80%, requiring a score of 12 items on the checklist and at least 4 of 5 for each scaled item. Using the MPS, 30% of students would require additional training after post-testing.Comments
We developed a SBML curriculum with a comprehensive assessment of BBN skills and a defensible competency standard. Future efforts will expand the mastery model to larger cohorts and assess the impact of rigorous education on patient care outcomes. 相似文献9.
Katherine M. Duszynski Nicole L. Pratt John W. Lynch Jesia G. Berry Michael S. Gold 《Vaccine》2019,37(2):280-288
Objective
To determine whether differences in combination DTaP vaccine types at 2, 4 and 6?months of age were associated with mortality (all-cause or non-specific), within 30?days of vaccination.Design
Observational nationwide cohort study.Setting
Linked population data from the Australian Childhood Immunisation Register and National Death Index.Participants
Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6?months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3?million children in the 2, 4 and 6?month vaccine cohorts, respectively.Main outcome measures
Infants were evaluated for the primary outcome of all-cause mortality within 30?days. A secondary outcome was non-specific mortality (unknown cause of death) within 30?days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 ‘Sudden infant death syndrome’, R96 ‘Other sudden death, cause unknown’, R98 ‘Unattended death’, R99 ‘Other ill-defined and unspecified cause of mortality’ or where no cause of death was recorded.Results
The rate of 30?day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6?month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort.Conclusion
Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality. 相似文献10.
Adilson Cunha Ferreira Edward Araujo Júnior Wellington P. Martins João Francisco Jordão Antônio Hélio Oliani Simon E. Meagher 《The journal of maternal-fetal & neonatal medicine》2015,28(14):1706-1710
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality. 相似文献