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   24514篇
  免费   1801篇
  国内免费   65篇
耳鼻咽喉   235篇
儿科学   929篇
妇产科学   814篇
基础医学   3129篇
口腔科学   251篇
临床医学   3117篇
内科学   4337篇
皮肤病学   569篇
神经病学   2363篇
特种医学   508篇
外科学   2575篇
综合类   253篇
一般理论   36篇
预防医学   3351篇
眼科学   328篇
药学   1628篇
中国医学   22篇
肿瘤学   1935篇
  2024年   28篇
  2023年   267篇
  2022年   318篇
  2021年   803篇
  2020年   493篇
  2019年   822篇
  2018年   855篇
  2017年   635篇
  2016年   663篇
  2015年   700篇
  2014年   977篇
  2013年   1405篇
  2012年   2145篇
  2011年   2258篇
  2010年   1163篇
  2009年   1050篇
  2008年   1663篇
  2007年   1753篇
  2006年   1570篇
  2005年   1389篇
  2004年   1232篇
  2003年   1109篇
  2002年   973篇
  2001年   188篇
  2000年   112篇
  1999年   151篇
  1998年   175篇
  1997年   103篇
  1996年   86篇
  1995年   88篇
  1994年   62篇
  1993年   51篇
  1992年   94篇
  1991年   78篇
  1990年   69篇
  1989年   76篇
  1988年   71篇
  1987年   53篇
  1986年   59篇
  1985年   57篇
  1984年   54篇
  1983年   42篇
  1982年   33篇
  1981年   31篇
  1980年   27篇
  1979年   56篇
  1978年   25篇
  1977年   25篇
  1974年   26篇
  1973年   26篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
991.
Abstract

It is critical for health professionals to continue to learn and this must be supported by health professions education (HPE). Adaptive expert clinicians are not only expert in their work but have the additional capacity to learn and improve in their practices. The authors review a selective aspect of learning to become an adaptive expert: the capacity to optimally balance routine approaches that maximize efficiency with innovative ones where energy and resources are used to customize actions for novel or difficult situations. Optimal transfer of learning, and hence the design of instruction, differs depending on whether the goal is efficient or innovative practice. However, the task is necessarily further complicated when the aspiration is an adaptive expert practitioner who can fluidly balance innovation with efficiency as the situation requires. Using HPE examples at both the individual and organizational level, the authors explore the instructional implications of learning to shift from efficient to innovative expert functioning, and back. They argue that the efficiency-innovation tension is likely to endure deep into the future and therefore warrants important consideration in HPE.  相似文献   
992.
993.
994.
995.
996.
The ability to locate catheter position in the left ventricle with respect to endocardial landmarks might enhance the accuracy of ventricular tachycardia mapping. An echo-transponder system (Telectronics, Inc.) was compared with biplane fluoroscopy for left ventricular endocardial mapping. A 6F electrode catheter was modified with the addition of a piezoelectric crystal 5 mm from the tip. This crystal was connected to a transponder that received and transmitted ultrasound, resulting in a discrete artifact on the two-dimensional echocardiographic image corresponding to the position of the catheter tip. Catheters were introduced percutaneously into the left ventricle of nine anesthetized dogs. Two-dimensional echo-transponder and biplane fluoroscopic images were recorded on videotape with the catheter at multiple endocardial sites. Catheter location was marked by delivering radiofrequency current to the distal electrode, creating a small endocardial lesion. Catheter location by echo-transponder and by fluoroscopy were compared with lesion location without knowledge of other data. Location by echo-transponder was 8.7 +/- 5.1 mm from the center of the radiofrequency lesion versus 14 + 7.8 mm by fluoroscopy (n = 15, p = 0.023). Echo-transponder localization is more precise than is biplane fluoroscopy and may enhance the accuracy of left ventricular electrophysiologic mapping.  相似文献   
997.
998.
To characterize changes in left ventricular morphology and function associated with renal transplantation, noninvasive cardiac evaluations were performed in 41 adults at the time of surgery and at follow-up. At the time of transplantation, 36 patients had undergone hemodialysis through a fistula for 2.3 +/- 2.5 years (mean +/- SD); their hematocrit level was 26 +/- 6% and systolic blood pressure was 151 +/- 19 mm Hg. Perioperatively, left ventricular hypertrophy was present in 93% of patients by echocardiography, but in only 37% by electrocardiography. Abnormal left ventricular diastolic function was present in 67% of patients and indicated a high risk for perioperative pulmonary edema. At follow-up (1.5 +/- 1.4 years), mean hematocrit level increased to 39 +/- 7%, systolic blood pressure decreased to 132 +/- 14 mm Hg and spontaneous closure of the fistula occurred in 13 patients. Left ventricular mass by echocardiography decreased from 237 +/- 66 to 182 +/- 47 g (p less than 0.001), a decrease of 23%. Left ventricular volumes and cardiac index also decreased significantly, reflecting the rapid resolution of a pretransplant high output state. Despite proportionate regression of left ventricular hypertrophy within months of transplantation, diastolic function did not improve. The significant regression of left ventricular hypertrophy that occurs after renal transplantation may help explain the improved cardiovascular survival of patients with a renal transplant over that of patients on long-term dialysis.  相似文献   
999.

Purpose of Review

Interest in consensually non-monogamous (CNM) relationships—in which partners have explicitly agreed that pursuing other romantic or sexual partners is permitted—has grown both among the American public and among researchers and practitioners. Yet, little is known about the prevalence of CNM relationships or factors related to engagement in these relationships.

Recent Findings

In this review, we synthesize the past 5 years of research on CNM relationships to provide insight on (1) definitions of differing CNM relationships, (2) how many people are engaging in or have previously engaged in CNM relationships, and (3) which social identities and individual differences are associated with CNM engagement.

Summary

Engagement in CNM relationships has been linked to positive aspects of sexual health such as open conversations about sexual needs and risk, and greater condom use. Researchers and practitioners should further address perceptions of and approaches to relationships outside the standard of monogamy.
  相似文献   
1000.
[Purpose] Examination and treatment of the long head of the biceps tendon (LHBT) requires accurate palpation. The purpose of this study was to determine physical therapists’ reliability and ability to accurately palpate the LHBT in two arm positions with ultrasound as the gold standard. [Participants and Methods] Examiners palpated the LHBT within the intertubercular groove (ITG) of the humerus on the bilateral shoulders of 32 asymptomatic (21 female; 24.3 ± 1.9 years) participants in 2 arm positions. The magnitude of distance between a marker and the border of the ITG was compared between 2 positions using an independent t-test. Percent accuracy was calculated. [Results] Inter-rater reliability was poor (position 1, k=1.04; position 2, k=0.016). Overall accuracy rate was 45.7% (117/256). Accuracy was 49.2% (63/128) and 42.2% (54/128) for testing position 1 and position 2 respectively. Mean distance palpated from the groove was M=2.58 mm (± 6.2 mm) for position 1 and M=3.77 mm (± 6.6 mm) for position 2. Inaccurate palpation occurred medially 72.3% (47/65) and 93.2% (69/74) in position 1 and position 2 respectively. [Conclusion] Results of this study did not support one arm position being more accurate over another for LHBT palpation.Key words: Palpation, Accuracy, Long head of biceps tendon  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