全文获取类型
收费全文 | 4378篇 |
免费 | 497篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 117篇 |
妇产科学 | 73篇 |
基础医学 | 558篇 |
口腔科学 | 135篇 |
临床医学 | 672篇 |
内科学 | 635篇 |
皮肤病学 | 56篇 |
神经病学 | 511篇 |
特种医学 | 120篇 |
外科学 | 671篇 |
综合类 | 53篇 |
一般理论 | 6篇 |
预防医学 | 513篇 |
眼科学 | 73篇 |
药学 | 394篇 |
中国医学 | 2篇 |
肿瘤学 | 252篇 |
出版年
2022年 | 28篇 |
2021年 | 84篇 |
2020年 | 54篇 |
2019年 | 77篇 |
2018年 | 81篇 |
2017年 | 61篇 |
2016年 | 69篇 |
2015年 | 101篇 |
2014年 | 94篇 |
2013年 | 147篇 |
2012年 | 234篇 |
2011年 | 249篇 |
2010年 | 135篇 |
2009年 | 129篇 |
2008年 | 235篇 |
2007年 | 226篇 |
2006年 | 227篇 |
2005年 | 231篇 |
2004年 | 214篇 |
2003年 | 202篇 |
2002年 | 196篇 |
2001年 | 124篇 |
2000年 | 133篇 |
1999年 | 106篇 |
1998年 | 57篇 |
1997年 | 40篇 |
1996年 | 36篇 |
1995年 | 51篇 |
1994年 | 34篇 |
1993年 | 32篇 |
1992年 | 73篇 |
1991年 | 64篇 |
1990年 | 67篇 |
1989年 | 68篇 |
1988年 | 54篇 |
1987年 | 73篇 |
1986年 | 64篇 |
1985年 | 40篇 |
1984年 | 51篇 |
1983年 | 45篇 |
1982年 | 24篇 |
1981年 | 28篇 |
1979年 | 42篇 |
1978年 | 33篇 |
1977年 | 25篇 |
1976年 | 29篇 |
1973年 | 30篇 |
1972年 | 33篇 |
1971年 | 25篇 |
1969年 | 29篇 |
排序方式: 共有4881条查询结果,搜索用时 15 毫秒
101.
Romain Galmiche Stphane Poitras Johanna Dobransky Paul R. Kim Robert J. Feibel Wade Gofton Hesham Abdelbary Paul E. Beaul 《Canadian journal of surgery》2020,63(2):E181
BackgroundThe most effective surgical approach to total hip replacement (THR) remains controversial. Most studies that have compared approaches have reported only short-term outcome data. It is therefore unclear in the literature if a particular surgical approach offers long-term advantages. The aim of this study was to determine the effect of the 3 main surgical approaches to THR on patient-reported outcomes 5 years after surgery.MethodsAll patients who underwent a THR for osteoarthritis or osteonecrosis between 2008 and 2012 by an anterior, posterior or lateral approach at The Ottawa Hospital in Ontario, Canada, were included in the study. All preoperative and postoperative scores for the Hip Disability and Osteoarthritis Outcome Score (HOOS) and Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC) questionnaires were recorded. Analysis of covariance was used to study the relationship between the amount of change in scores on the HOOS and WOMAC subscales (dependent variables) and the surgical approach. The confounding factors of age, sex, American Society of Anesthesiologists (ASA) class, Charnley classification and body mass index were included in the analysis.ResultsThere were 138 patients (37.6%) in the posterior approach group, 104 (28.3%) in the lateral approach group and 125 (34.1%) in the anterior approach group. There were no significant differences among the 3 groups in terms of Charnley classification, body mass index, sex, ASA class, surgical side and preoperative functional scores. We did not observe any significant differences in the amount of change in the scores for HOOS and WOMAC subscales among the 3 groups. There were also no differences in the final postoperative scores.ConclusionOur findings suggest that the choice of surgical approach in primary THR surgery without revision has no influence on functional outcomes and quality of life after 5 years. Further studies are needed to assess how patient age and sex may influence the functional outcome of individual surgical approaches. 相似文献
102.
103.
104.
Chronic exposure to low concentrations of strontium 90 affects bone physiology but not the hematopoietic system in mice 下载免费PDF全文
Nicholas Synhaeve Ndéye Marième Wade‐Gueye Stefania Musilli Johanna Stefani Line Grandcolas Gaëtan Gruel Maâmar Souidi Isabelle Dublineau Jean‐Marc Bertho 《Journal of applied toxicology : JAT》2014,34(1):76-86
The aim of this work was to delineate the effects of chronic ingestion of strontium 90 (90Sr) at low concentrations on the hematopoiesis and the bone physiology. A mouse model was used for that purpose. Parent animals ingested water containing 20 kBq l?1 of 90Sr two weeks before mating. Offspring were then continuously contaminated with 90Sr through placental transfer during fetal life, through lactation after birth and through drinking water after weaning. At various ages between birth and 20 weeks, animals were tested for hematopoietic parameters such as blood cell counts, colony forming cells in spleen and bone marrow and cytokine concentrations in the plasma. However, we did not find any modification in 90Sr ingesting animals as compared with control animals. By contrast, the analysis of bone physiology showed a modification of gene expression towards bone resorption. This was confirmed by an increase in C‐telopeptide of collagen in the plasma of 90Sr ingesting animals as compared with control animals. This modification in bone metabolism was not linked to a modification of the phosphocalcic homeostasis, as measured by calcium, phosphorus, vitamin D and parathyroid hormone in the blood. Overall these results suggest that the chronic ingestion of 90Sr at low concentration in the long term may induce modifications in bone metabolism but not in hematopoiesis. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
105.
106.
Frederick R. Taylor MD FAAN FAHS Wade M. Cooper DO Robert G. Kaniecki MD 《Headache》2019,59(8):1407-1418
107.
David Saliken Nancy Dudek Timothy J. Wood Matthew MacEwan Wade T. Gofton 《Teaching and learning in medicine》2019,31(2):146-153
Construct: We compared a single-item performance score with the Ottawa Surgical Competency Operating Room Evaluation (O-SCORE) for their ability in assessing surgical competency. Background: Surgical programs are adopting competency-based frameworks. The adoption of these frameworks for assessment requires tools that produce accurate and valid assessments of knowledge and technical performance. An assessment tool that is quick to complete could improve feasibility, reduce delays, and result in a higher volume of assessments of learners. Previous work demonstrated that the 9-item O-SCORE can produce valid results; the goal of this study was to determine if a single-item performance rating (Is candidate competent to independently complete procedure: yes or no) completed at a separate viewing would correlate to the O-SCORE, thus increasing feasibility of procedural competence assessment. Approach: Nineteen residents and 2 staff orthopedic surgeons from the University of Ottawa volunteered for a 2-part OSCE-style station including a written questionnaire and videotaped simulated open reduction and internal fixation midshaft radius fracture. Each performance was rated independently by 3 orthopedic surgeons using a single-item performance score (Time 1). The performances were assessed again 6?weeks later by the 3 raters using the O-SCORE (Time 2). Correlation between the single-item performance score and the O-SCORE were evaluated. Results: Three orthopedic surgeons completed 21 ratings each resulting in 63 orthopedic ratings. There was a high level of correlation and agreement between the single-item performance score at Time 1 and Time 2 (κ correlation =0.72–1.00; p?<?.001; percentage agreement =90%–100%). The reliability of the O-SCORE at Time 2 with three raters was 0.83 and the internal consistency was 0.89. There was a tendency for each rater to assign more yes responses to the more senior trainees. Conclusions: A single-item performance score correlated highly with the O-SCORE in an orthopedic setting. A single-item score could be used to supplement a multi-item score with similar results in orthopedics. There is still benefit in completing multi-item scores such as the O-SCORE evaluations to guide specific areas of improvement and direct feedback. 相似文献
108.
Chernyak A Kondo S Wade TK Meeks MD Alzari PM Fournier JM Taylor RK Kovác P Wade WF 《The Journal of infectious diseases》2002,185(7):950-962
Synthetic antigens that mimic the terminal hexasaccharide epitope of the O-specific polysaccharide of Vibrio cholerae O1, serotype Ogawa, were conjugated to bovine serum albumin (BSA). Conjugates with carbohydrate-to-carrier molar ratios of 15.5:1, 9.2:1, and 4.6:1 were tested for immunogenicity and efficacy in mice. The role of preimmunity to BSA and the use of adjuvant in the generation of the serologic response to the O-specific polysaccharide and protection against virulent V. cholerae was examined. Preimmunity to BSA did not affect the anti-Ogawa titers but seemed to enhance the protective capacity of antiserum. All 3 conjugates were immunogenic, but adjuvant was effective at inducing higher and earlier antibody responses. In tertiary serum samples, a correlation was found between vibriocidal activity and protection. The protective capacity of antiserum was evident in serum from mice immunized with all conjugates, but it was highest in the groups that received the conjugate with the lowest level of substitution. Further studies are required to increase understanding of the reason for differential protection. 相似文献
109.
110.
Anticentromere antibodies--clinical correlates 总被引:1,自引:0,他引:1
We tested 11,594 consecutive sera for antinuclear antibodies and 1,502 were found to be positive; 68 patients (72 sera) had anticentromere antibodies. A retrospective analysis of the clinical characteristics and diagnoses of patients found to have anticentromere antibodies were correlated and showed a diverse array of findings. The association of anticentromere antibodies and the CREST variant of scleroderma may be less specific than originally thought when used as a screening test in an unselected population with rheumatic disease. Anticentromere antibody was present in patients with drug induced lupus, a finding not previously reported. 相似文献