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   39537篇
  免费   2613篇
  国内免费   128篇
耳鼻咽喉   369篇
儿科学   974篇
妇产科学   938篇
基础医学   5108篇
口腔科学   645篇
临床医学   3827篇
内科学   7626篇
皮肤病学   588篇
神经病学   4108篇
特种医学   1279篇
外科学   6504篇
综合类   468篇
现状与发展   1篇
一般理论   35篇
预防医学   3264篇
眼科学   1011篇
药学   2647篇
中国医学   114篇
肿瘤学   2772篇
  2023年   223篇
  2022年   399篇
  2021年   882篇
  2020年   543篇
  2019年   796篇
  2018年   1012篇
  2017年   719篇
  2016年   722篇
  2015年   855篇
  2014年   1328篇
  2013年   1718篇
  2012年   2796篇
  2011年   2920篇
  2010年   1643篇
  2009年   1482篇
  2008年   2659篇
  2007年   2844篇
  2006年   2671篇
  2005年   2617篇
  2004年   2500篇
  2003年   2365篇
  2002年   2165篇
  2001年   379篇
  2000年   333篇
  1999年   381篇
  1998年   440篇
  1997年   388篇
  1996年   379篇
  1995年   310篇
  1994年   297篇
  1993年   261篇
  1992年   226篇
  1991年   192篇
  1990年   160篇
  1989年   151篇
  1988年   167篇
  1987年   151篇
  1986年   137篇
  1985年   140篇
  1984年   146篇
  1983年   157篇
  1982年   193篇
  1981年   171篇
  1980年   146篇
  1979年   85篇
  1978年   114篇
  1977年   115篇
  1976年   87篇
  1975年   89篇
  1974年   75篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
The right atrium has a significantly higher capacitance than the left atrium, and this may affect the Doppler flow pattern across an atrial septal defect (ASD) in unilateral atrioventricular (AV) valve atresia. This Doppler flow pattern is often used to assess ASD adequacy in this setting. We studied the effect of atrial capacitance and ASD size on the trans-ASD Doppler flow pattern in an in vivo flow model of alternate left or right AV valve atresia (LAVVA and RAVVA). We assessed trans-ASD Doppler flow patterns using the max/min velocity ratio and mean interatrial pressure gradients (PGs). In both models, ASD flow rate correlated with mean trans-ASD PG, but for similar flow rates the slope was higher in the LAVVA model. In LAVVA, a persistent PG was consistently observed, with low max/min ratio (median, 1.46; range, 1.03-3.13), whereas in RAVVA, phasic flow was common (median, 8.0; range, 2.8-20). Because atrial capacitance affects mean PG and Doppler flow pattern across the ASD, we propose that the assessment of ASD adequacy in RAVVA should not rely on Doppler findings.  相似文献   
993.
BackgroundReverse total shoulder arthroplasty (RSA) primarily varies between 2 implant design options: a 135 humeral stem inclination that closely resembles anatomic orientation, versus the Grammont-style 155 humeral stem inclination that further medializes and distalizes the center of rotation (COR). The purpose of this study was to compare deltoid force, glenoid strain, and simulated glenohumeral range of motion (ROM) between RSA 135 and RSA 155 designs, with a series of standardized permutations of glenosphere offset and rotator cuff pathology.MethodsTwelve fresh-frozen cadaveric shoulder specimens were studied using a shoulder simulator. Native shoulder motion profiles for reproducible abduction range of motion were established using a customized testing device. Optical 3-dimensional tracking and pressure sensors were used to accurately record glenohumeral range of motion (ROM), deltoid force, and glenoid strain for RSA 135 and RSA 155 designs. For each cohort, all combinations of glenosphere offsets and rotator cuff tendon involvement were evaluated.ResultsThere was no significant difference in the overall abduction ROM between the 155 and the 135 humeral stem implants (P = .75). Resting abduction angle and maximum abduction angle were significantly greater with a 155 + STD (standard offset) construct than with a 135 + STD construct (P < .001 and P = .01, respectively). Both stem inclinations decreased combined deltoid force requirements as compared the native shoulder with a massive cuff tear. Effective glenoid strain did not vary significantly between 135 + STD and 155 + STD constructs (P = .66).ConclusionOverall, range of motion between the 135 and the 155 humeral stem inclinations was not significantly different. The cumulative deltoid force was lower in RSA shoulders when compared to native shoulders with massive rotator cuff tears, highlighting the utility of both implant designs. The Grammont-style 155 stem coupled with a 2.5 mm inferior offset glenosphere required less deltoid force to reach maximum abduction than did the more anatomic, lateralized 135 stem coupled with a 4 mm lateral offset glenosphere.Level of EvidenceBasic Science, Biomechanics Controlled Laboratory Study  相似文献   
994.
BackgroundThe purpose of this study is to determine the comparative risk profile and clinical outcomes for patients undergoing reverse total shoulder arthroplasty (RTSA) for cuff tear arthropathy (CTA) without failed prior rotator cuff repair (RCR) compared with RTSA for CTA with prior RCR.MethodsFrom 2006 to 2014, all patients who underwent RTSA by two surgeons after failed RCR with minimum 2-year follow-up were identified. Patients who underwent RTSA with failed prior RCR were matched in a 1:1 ratio to patients undergoing primary RTSA, while controlling for demographic factors, prosthesis design, and surgeon. Postoperative active forward elevation and active external rotation were recorded. Outcome measures included American Shoulder and Elbow Surgeons score, Visual Analog Scale (VAS), and Simple Shoulder Test. Perioperative complications and rates of secondary reoperation were noted, and comparative multivariate analysis was performed.ResultsOf 262 patients, 192 (73.3%) were available at minimum 2-year follow-up. The prior RCR group had a significantly higher complication rate (17.4%, n = 15) than the primary RTSA group (3.8%, n = 4) (P = .001), although no significant difference in periprosthetic infection (P = .469) or secondary revision rate (P = .136) was observed. At mean 36.3 ± 26.1-month follow-up, the prior RCR group had statistically worse American Shoulder and Elbow Surgeons score (P < .001), VAS (P = .001), Simple Shoulder Test (P < .001), and active forward elevation (P = .006). Patients with multiple failed RCR attempts (n = 38) before RTSA demonstrated no significant differences versus isolated failed RCR (n = 48; P > .05).ConclusionThis study demonstrated that patients with RTSA after prior failed RCR have significantly worse patient-reported outcomes and greater rate of perioperative complications than patients undergoing primary RTSA for CTA.  相似文献   
995.
World Journal of Surgery - Trauma is a leading cause of morbidity and mortality worldwide, and patients in low- and middle-income countries are disproportionately affected. Organized trauma...  相似文献   
996.
997.
998.
999.
Recent evidence of the occurrence of discrimination, bullying and sexual harassment in surgery and more generally within healthcare has led to widespread discussion about the effects of unacceptable behaviour in surgical education and practice. Despite accumulating evidence of the adverse effects of unacceptable behaviour in clinical practice, not only on health care professionals but on patient care and outcomes, many surgeons and other health care professionals continue to embrace false perceptions about appropriate professional behaviour, interactions and approaches to teaching within surgical departments and more generally within healthcare institutions. This article explores five misperceptions about unacceptable behaviour in surgical education and provides evidence that supports a change in practice.  相似文献   
1000.
Context: Patient-reported outcome measures (PROMs) are valuable for capturing the impact of spasticity on health-related quality of life (HRQoL) in persons with spinal cord damage (SCD) and evaluating the efficacy of interventions.Objective: To provide practical guidance for measuring HRQoL in persons with spasticity following SCD.Methods: Literature reviews identified measures of HRQoL and caregiver burden, utilized in studies addressing spasticity in SCD. Identified measures were evaluated for clinical relevance and practicality for use in clinical practice and research. The PRISM, SCI-SET, EQ-5D and SF-36 instruments were mapped to the International Classification of Functioning, Disability and Health (ICF). The PRISM and SCI-SET were evaluated using the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist.Results: Two spasticity-specific, five generic, and four preference-based measures were identified. ICF mapping and the COSMIN checklist supported the use of the PRISM and SCI-SET in SCD. The SF-36 is considered the most useful generic measure; disability-adapted versions may be more acceptable but further studies on psychometric properties are required. The SF-36 can be converted to a preference-based measure (SF-6D), or alternatively the EQ-5D can be used. While no measures specific to caregivers of people with SCD were identified, the Caregiver Burden Scale and the Zarit Burden Interview are considered suitable.Conclusion: Recommended measures include the PRISM and SCI-SET (condition-specific), SF-36 (generic), and Caregiver Burden Scale and Zarit Burden Interview (caregiver burden). Consideration should be given to using condition-specific and generic measures in combination; the PRISM or SCI-SET combined with SF-36 is recommended.  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