全文获取类型
收费全文 | 1455079篇 |
免费 | 104365篇 |
国内免费 | 3474篇 |
专业分类
耳鼻咽喉 | 21241篇 |
儿科学 | 43326篇 |
妇产科学 | 40820篇 |
基础医学 | 202807篇 |
口腔科学 | 42528篇 |
临床医学 | 124559篇 |
内科学 | 286852篇 |
皮肤病学 | 31921篇 |
神经病学 | 117008篇 |
特种医学 | 58281篇 |
外国民族医学 | 435篇 |
外科学 | 227658篇 |
综合类 | 32736篇 |
现状与发展 | 7篇 |
一般理论 | 605篇 |
预防医学 | 103298篇 |
眼科学 | 33915篇 |
药学 | 108584篇 |
6篇 | |
中国医学 | 3153篇 |
肿瘤学 | 83178篇 |
出版年
2018年 | 14415篇 |
2016年 | 12606篇 |
2015年 | 14305篇 |
2014年 | 20290篇 |
2013年 | 30714篇 |
2012年 | 40882篇 |
2011年 | 43191篇 |
2010年 | 25436篇 |
2009年 | 24484篇 |
2008年 | 40953篇 |
2007年 | 44666篇 |
2006年 | 44852篇 |
2005年 | 43671篇 |
2004年 | 42523篇 |
2003年 | 41065篇 |
2002年 | 40433篇 |
2001年 | 64792篇 |
2000年 | 66316篇 |
1999年 | 56662篇 |
1998年 | 16103篇 |
1997年 | 14607篇 |
1996年 | 14051篇 |
1995年 | 13272篇 |
1994年 | 12368篇 |
1992年 | 43527篇 |
1991年 | 42084篇 |
1990年 | 41239篇 |
1989年 | 40214篇 |
1988年 | 37645篇 |
1987年 | 37055篇 |
1986年 | 35570篇 |
1985年 | 33845篇 |
1984年 | 25628篇 |
1983年 | 21777篇 |
1982年 | 13634篇 |
1981年 | 12541篇 |
1980年 | 11596篇 |
1979年 | 24437篇 |
1978年 | 17612篇 |
1977年 | 15331篇 |
1976年 | 13829篇 |
1975年 | 15667篇 |
1974年 | 18475篇 |
1973年 | 17937篇 |
1972年 | 17072篇 |
1971年 | 15976篇 |
1970年 | 15143篇 |
1969年 | 14520篇 |
1968年 | 13617篇 |
1967年 | 12139篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
91.
92.
M.A. Mashrah T.A. Aldhohrah A. Abdelrehem Moustafa H.M. Al-Sharani A. Alrmali L. Wang 《International journal of oral and maxillofacial surgery》2021,50(1):21-31
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
93.
Alexander Real Chierika Ukogu Divya Krishnamoorthy Nicole Zubizarreta Samuel K. Cho Andrew C. Hecht James C. Iatridis 《The spine journal》2019,19(2):225-231
Background Context
Low back pain (LBP) is a common complaint in clinical practice of multifactorial origin. Although obesity has been thought to contribute to LBP primarily by altering the distribution of mechanical loads on the spine, the additional contribution of obesity-related conditions such as diabetes mellitus (DM) to LBP has not been thoroughly examined.Purpose
To determine if there is a relationship between DM and LBP that is independent of body mass index (BMI) in a large cohort of adult survey participants.Study Design
Retrospective analysis of prospectively collected National Health and Nutrition Examination Survey (NHANES) data to characterize associations between LBP, DM, and BMI in adults subdivided into 6 subpopulations: normal weight (BMI 18.5–25), overweight (BMI 25–30), and obese (BMI >30) diabetics and nondiabetics. Diabetes was defined with glycohemoglobin A1c (HbA1c) ≥6.5%.Patient Sample
11,756 participants from NHANES cohort.Outcome Measures
Percentage of LBP reported.Methods
LBP reported in the 1999-2004 miscellaneous pain NHANES questionnaire was the dependent variable examined. Covariates included HbA1c, BMI, age, and family income ratio to poverty as continuous variables as well as race, gender, and smoking as binary variables. Individuals were further subdivided by weight class and diabetes status. Regression and graphical analyses were performed on the study population as a whole and also on subpopulations.Results
Increasing HbA1c did not increase the odds of reporting LBP in the full cohort. However, multivariate logistic regression of the 6 subpopulations revealed that the odds of LBP significantly increased with increasing HbA1c levels in normal weight diabetics. No other subpopulations reported significant relationships between LBP and HbA1c. LBP was also significantly associated with BMI for normal weight diabetics and also for obese subjects regardless of their DM status.Conclusions
LBP is significantly related to DM status, but this relationship is complex and may interact with BMI. These results support the concept that LBP may be improved in normal weight diabetic subjects with improved glycemic control and weight loss, and that all obese LBP subjects may benefit from improved weight loss alone. 相似文献94.
95.
Eloise R. Galligan Leila H. Shayegan Christine T. Lauren Kimberly D. Morel 《Pediatric dermatology》2019,36(5):753-754
Shaving and other modes of epilation can cause undue anxiety, pain, or skin irritation in children. Here, we present hair trimming as a safe, painless, and cost‐effective alternative for patients with unwanted hair which may be performed indefinitely or until the child is old enough to direct management. In select cases, removing unwanted hair using this technique may facilitate dermatologic surveillance. 相似文献
96.
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97.
Kelly H. M. Cooijmans Roseriet Beijers Bonnie E. Brett Carolina de Weerth 《Maternal & child nutrition》2022,18(1):e13241
This randomized controlled trial evaluated the effect of a 5-week daily skin-to-skin contact (SSC) intervention between mothers and their full-term infants, compared with care-as-usual, on exclusive and continued breastfeeding duration during the first post-natal year. Healthy pregnant women (n = 116) from a community sample were enrolled and randomly allocated to the SSC or care-as-usual condition. SSC mothers were requested to provide one daily hour of SSC for the first five post-natal weeks. Twelve months post-partum, mothers indicated the number of exclusive and continued breastfeeding months. Multiple regression analyses were conducted using intention-to-treat, per-protocol and exploratory dose–response frameworks. In intention-to-treat analyses, exclusive and continued breastfeeding duration was not different between groups (exclusive: 3.61 ± 1.99 vs. 3.16 ± 1.77 months; adjusted mean difference 0.28, 95% confidence interval [CI] ?0.33 to 0.89; p = 0.36; continued: 7.98 ± 4.20 vs. 6.75 ± 4.06 months; adjusted mean difference 0.81, 95% CI ?0.46 to 2.08; p = 0.21). In per-protocol analyses, exclusive and continued breastfeeding duration was longer for SSC than care-as-usual dyads (exclusive: 4.89 ± 1.26 vs. 3.25 ± 1.80 months; adjusted mean difference 1.28, 95% CI 0.31–2.24; p = 0.01; continued: 10.81 ± 1.97 vs. 6.98 ± 4.08 months; adjusted mean difference 2.33, 95% CI 0.13–4.54; p = 0.04). Exploratory dose–response effects indicated that more SSC hours predicted longer exclusive and continued breastfeeding duration. This study demonstrates that for the total group, the 5-week daily SSC intervention did not extend exclusive and continued breastfeeding duration. However, for mothers performing a regular daily hour of SSC, this simple and accessible intervention may extend exclusive and continued breastfeeding duration by months. Future studies are required to confirm these promising findings. Trial registration: Netherlands Trial Register (NTR5697). 相似文献
98.
Sarah E. Henderson Shana A. Hall Jessica M. Callegari James A. Desjardins Sidney J. Segalowitz Karen L. Campbell 《Psychophysiology》2022,59(1):e13947
Recent work suggests that while voluntary episodic memory declines with age, involuntary episodic memory, which comes to mind spontaneously without intention, remains relatively intact. However, the neurophysiology underlying these differences has yet to be established. The current study used electroencephalography (EEG) to investigate voluntary and involuntary retrieval in older and younger adults. Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization cover task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later reported which sounds brought the paired picture to mind during the localization task. Reaction times on the localization task were slower for voluntary than involuntary retrieval and for paired than unpaired sounds, possibly reflecting increased attentional demands of voluntary retrieval and interference from reactivation of the associated pictures respectively. For the EEG analyses, young adults showed greater alpha event-related desynchronization (ERD) during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD regardless of intention. Additionally, older adults showed greater ERD for paired than unpaired sounds at occipital sites, likely reflecting visual reactivation of the associated pictures. Young adults did not show this alpha ERD memory effect. Taken together, these data suggest that involuntary memory is largely preserved with age, but this may be due to older adults' greater recruitment of top-down control even when demand for such control is limited. 相似文献
99.
Gregory S. Orgel Robert A. Weston Christopher Ziebell Lawrence H. Brown 《The American journal of emergency medicine》2019,37(9):1729-1733
ObjectiveTo evaluate changes in insurance status among emergency department (ED) patients presenting in the two years immediately before and after full implementation of the Affordable Care Act (ACA).MethodsWe evaluated National Hospital Ambulatory Medical Care Survey (NHAMCS) Emergency Department public use data for 2012–2015, categorizing patients as having any insurance (private; Medicare; Medicaid; workers' compensation) or no insurance. We compared the pre- and post-ACA frequency of insurance coverage—overall and within the older (≥65), working-age (18–64) and pediatric (<18) subpopulations—using unadjusted odds ratios with 95% confidence intervals. We also conducted a difference-in-differences analysis comparing the change in insurance coverage among working-age patients with that observed for older Medicare-eligible patients, while controlling for sex, race and underlying temporal trends.ResultsOverall, the proportion of ED patients with any insurance did not significantly change from 2012 to 2013 to 2014–2015 (74.2% vs 77.7%) but the proportion of working-age adult patients with at least one form of insurance increased significantly, from 66.0% to 71.8% (OR 1.31, CI: 1.13–1.52). The difference-in-differences analysis confirmed the change in insurance coverage among working-age adults was greater than that seen in the reference population of Medicare-eligible adults (AOR 1.70, CI: 1.29–2.23). The increase was almost entirely attributable to increased Medicaid coverage.ConclusionIn the first two years following full implementation of the ACA, there was a significant increase in the proportion of working-age adult ED patients who had at least one form of health insurance. The increase appeared primarily associated with expansion of Medicaid. 相似文献
100.