全文获取类型
收费全文 | 13936篇 |
免费 | 1280篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 248篇 |
儿科学 | 343篇 |
妇产科学 | 514篇 |
基础医学 | 1463篇 |
口腔科学 | 260篇 |
临床医学 | 1339篇 |
内科学 | 2794篇 |
皮肤病学 | 261篇 |
神经病学 | 1400篇 |
特种医学 | 624篇 |
外国民族医学 | 2篇 |
外科学 | 2398篇 |
综合类 | 193篇 |
一般理论 | 4篇 |
预防医学 | 1117篇 |
眼科学 | 354篇 |
药学 | 660篇 |
中国医学 | 11篇 |
肿瘤学 | 1263篇 |
出版年
2021年 | 157篇 |
2020年 | 119篇 |
2019年 | 212篇 |
2018年 | 213篇 |
2017年 | 190篇 |
2016年 | 210篇 |
2015年 | 229篇 |
2014年 | 328篇 |
2013年 | 467篇 |
2012年 | 693篇 |
2011年 | 727篇 |
2010年 | 411篇 |
2009年 | 349篇 |
2008年 | 609篇 |
2007年 | 675篇 |
2006年 | 706篇 |
2005年 | 653篇 |
2004年 | 597篇 |
2003年 | 648篇 |
2002年 | 554篇 |
2001年 | 325篇 |
2000年 | 377篇 |
1999年 | 350篇 |
1998年 | 168篇 |
1997年 | 118篇 |
1996年 | 132篇 |
1995年 | 124篇 |
1994年 | 101篇 |
1993年 | 105篇 |
1992年 | 261篇 |
1991年 | 273篇 |
1990年 | 266篇 |
1989年 | 252篇 |
1988年 | 219篇 |
1987年 | 213篇 |
1986年 | 229篇 |
1985年 | 241篇 |
1984年 | 179篇 |
1983年 | 180篇 |
1982年 | 137篇 |
1981年 | 125篇 |
1980年 | 105篇 |
1979年 | 183篇 |
1978年 | 133篇 |
1977年 | 125篇 |
1976年 | 111篇 |
1975年 | 120篇 |
1974年 | 144篇 |
1973年 | 136篇 |
1972年 | 113篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Elizabeth D. Krebs Robert B. Hawkins J. Hunter Mehaffey Clifford E. Fonner Alan M. Speir Mohammed A. Quader Jeffrey B. Rich Leora T. Yarboro Nicholas R. Teman Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1533-1542.e2
Objectives
Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.Methods
Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.Results
A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.Conclusions
Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight. 相似文献2.
3.
Stefaniuk Catherine M. Schlegelmilch June Meyerson Howard J. Harding Clifford V. Maitta Robert W. 《Journal of thrombosis and thrombolysis》2022,53(4):950-953
Journal of Thrombosis and Thrombolysis - Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially... 相似文献
4.
5.
6.
7.
C. M. Gordon E. Binello M. S. LeBoff M. E. Wohl C. J. Rosen A. A. Colin 《Osteoporosis international》2006,17(5):783-790
Introduction Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss
are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients
between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA)
and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1β, tumor necrosis factor α,
and interleukin-6.
Methods We studied 32 outpatients (18 females; mean age: 26.2 ± 7.9 years) at a tertiary care medical center. The subjects had venous
samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum
IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations
were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse
correlation between IL-1β and BMD at all sites.
Results In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate
models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant
independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits
in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD.
Conclusions These findings may have therapeutic implications for enhancing bone density in these patients. 相似文献
8.
Clinical experience with immediate breast reconstruction using tissue expansion or transverse rectus abdominis musculocutaneous flaps 总被引:5,自引:0,他引:5
We retrospectively reviewed our experience with immediate breast reconstruction in 103 consecutive patients with stage 0 or I breast carcinoma between May 1983 and April 1988. Two reconstructive techniques were used, that is, either tissue expansion with secondary prosthesis implantation (60%) or transverse rectus abdominis musculocutaneous (TRAM) flap (40%). Chemotherapy was administered in 22% of patients without delay or compromise. The mean length of follow-up is 30 months. The complication rate was equal for both groups (24%) with infection being most common in the group of patients with tissue expansion and partial flap necrosis being most common in the group of patients with TRAM flaps. Aesthetic results were superior with use of the TRAM flap. Our experience concurs with previous reports that documented satisfactory results with immediate breast reconstruction without compromising further therapy. We conclude that although the tissue expansion technique yields acceptable results, the TRAM flap yields superior aesthetic results in terms of both appearance and consistency. 相似文献
9.
10.
Scott A Fields Elizabeth Morrison Ernie Yoder Kevin Krane Thomas Agresta Rich Esham Frederick McCurdy Jonathan Rosen James Shumway 《Academic medicine》2002,77(6):543-546
PURPOSE: Chart notes are used to support billing codes under the evaluation and management guidelines of the Health Care Financing Administration (HCFA), in addition to serving as a record of the visit. To better understand the effect of the HCFA documentation guidelines, the authors collected data on how the guidelines affect participation by university- and community-based faculty in clinical education programs. METHOD: In 2000, the authors sent six copies of their questionnaire to the associate deans of the 125 U.S. medical schools and requested they distribute them to all core clerkship directors. The questionnaire consisted of multiple-choice and short-answer questions regarding documentation of medical visits, participation of community-based faculty, understanding of HCFA documentation guidelines, and effects on education programs. RESULTS: The response rate was about 50%. Most of the 379 clerkship directors who responded (77%) stated they were aware the HCFA documentation guidelines include specifications regarding the role medical students can play and documentation of medical visits, and 64% indicated they were concerned the guidelines would affect their educational programs. Concerns included the loss of student independence and active participation in the patient care environment (37), time constraints and the changing balance between education and service (16), loss of faculty and decreased morale (11), and decreased quality of care for patients (7). CONCLUSION: Leaders of medical education must work to modify these guidelines to protect the quality of patients' care, while maximizing students' educational opportunity and participation. 相似文献