全文获取类型
收费全文 | 26988篇 |
免费 | 1785篇 |
国内免费 | 245篇 |
专业分类
耳鼻咽喉 | 424篇 |
儿科学 | 414篇 |
妇产科学 | 590篇 |
基础医学 | 3919篇 |
口腔科学 | 694篇 |
临床医学 | 2321篇 |
内科学 | 5135篇 |
皮肤病学 | 584篇 |
神经病学 | 2017篇 |
特种医学 | 1600篇 |
外科学 | 4348篇 |
综合类 | 284篇 |
一般理论 | 10篇 |
预防医学 | 1108篇 |
眼科学 | 662篇 |
药学 | 2338篇 |
1篇 | |
中国医学 | 271篇 |
肿瘤学 | 2298篇 |
出版年
2023年 | 162篇 |
2022年 | 383篇 |
2021年 | 709篇 |
2020年 | 387篇 |
2019年 | 663篇 |
2018年 | 718篇 |
2017年 | 593篇 |
2016年 | 687篇 |
2015年 | 1016篇 |
2014年 | 1254篇 |
2013年 | 1428篇 |
2012年 | 2129篇 |
2011年 | 2091篇 |
2010年 | 1290篇 |
2009年 | 1186篇 |
2008年 | 1627篇 |
2007年 | 1554篇 |
2006年 | 1451篇 |
2005年 | 1378篇 |
2004年 | 1242篇 |
2003年 | 1083篇 |
2002年 | 954篇 |
2001年 | 773篇 |
2000年 | 760篇 |
1999年 | 600篇 |
1998年 | 211篇 |
1997年 | 198篇 |
1996年 | 174篇 |
1995年 | 147篇 |
1994年 | 124篇 |
1993年 | 102篇 |
1992年 | 242篇 |
1991年 | 184篇 |
1990年 | 175篇 |
1989年 | 166篇 |
1988年 | 143篇 |
1987年 | 103篇 |
1986年 | 95篇 |
1985年 | 69篇 |
1984年 | 78篇 |
1983年 | 49篇 |
1982年 | 52篇 |
1981年 | 44篇 |
1980年 | 43篇 |
1979年 | 56篇 |
1978年 | 44篇 |
1977年 | 46篇 |
1974年 | 37篇 |
1972年 | 44篇 |
1971年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Eugene H. Chung David E. McNeely III Anil K. Gehi Thomas Brickner Sharon Evans Edmund Pryski Kelly Waicus Harry Stafford J. Paul Mounsey Jennifer D. Schwartz Sihong Huang Irion Pursell Mario Ciocca 《Journal of electrocardiology》2014
Background
Displacement of ECG leads can result in unwarranted findings. We assessed the frequency of Brugada-type patterns in athletes when precordial leads were purposely placed upward.Methods
Four hundred ninety-one collegiate athletes underwent two ECGs: one with standard leads, one with V1 and V2 along the 2nd intercostal space. A positive Brugada-type pattern was defined as ST elevation in V1 or V2 consistent with a Type 1, 2, or 3 pattern in the high-lead ECG. A control group was comprised of 181 outpatients.Results
No Type 1 patterns were seen. In 58 athletes (11.8%), a Brugada-type 2 or 3 pattern was observed. Those with Brugada-type 2 or 3 patterns were more likely male, taller, and heavier. In the control group, 18 (9.9%) had Brugada-type 2 or 3 patterns and were more likely male.Conclusions
Proper lead positioning is essential to avoid unwarranted diagnosis of a Brugada-type ECG, especially in taller, heavier male athletes. 相似文献993.
Jun Chul Park Jae Jun Park Kungseok Cheoi Hyunsoo Chung Hyuk Lee Sung Kwan Shin Sang Kil Lee Yong Chan Lee 《Digestive and liver disease》2012,44(12):999-1005
Background
Although a substantial number of patients require secondary stents insertion due to primary stent malfunction in malignant gastric outlet obstruction, data on the outcomes of secondary self-expanding metal stents are sparse.Aim
To investigate clinical outcomes and factors related with secondary stent malfunction in patients with malignant gastric outlet obstruction given secondary stent-in-stent self-expanding metal stent insertion.Methods
For this retrospective study, a total 77 patients who underwent secondary stent-in-stent self-expanding metal stent placement for primary stent malfunction in malignant gastric outlet obstruction were enrolled. We compared the effectiveness and complications of secondary covered and uncovered stents and explored the predictive factors for stent malfunction.Results
Stent-in-stent self-expanding metal stent placements were technically successful in all patients. Both groups also had comparable clinical success rates (covered stent, 87.2% and uncovered stent, 90.0%, P = 1.000). Stent malfunction rates (31.9% and 36.7% respectively, P = 0.805) and median patency time of stent (165 [95% confidence interval: 112–218] and 165 [95% confidence interval: 126–204] days, respectively, P = 0.358) were similar between secondary covered and uncovered stents. Longer patients’ survival time (≥100 days) was associated with increased risk of stent malfunction (odds ratio: 4.598; 95% confidence interval: 1.473–14.355; P = 0.009).Conclusions
Secondary stent-in-stent self-expanding metal stent placement is feasible and effective treatment for primary stent malfunctions in malignant gastric outlet obstruction. Covered and uncovered stent are equally acceptable in terms of stent-related complications and stent patency, regardless of primary stent type. 相似文献994.
995.
Ji‐Won Kim Yuri Kwon Hong‐Young Chung Gwang‐Moon Eom Jae‐Hoon Jun Jin‐Sang Chung Byung Kyu Park 《Geriatrics & Gerontology International》2011,11(3):333-340
Aim: Elderly women are reported to have worse postural balance in the mediolateral direction than elderly men, which may be related to hip lateral muscle properties. The purpose of this study was to investigate the effects of sex, age and their interactions on hip abductor muscle properties. Methods: Thirty elderly and 30 young healthy subjects were recruited in this study. Subjects were instructed to abduct their leg as forcefully and quickly as possible under isometric condition, in response to audible beeps. Electromyogram was measured on the gluteus medius muscle and abduction torque was measured. Investigated muscle properties included torque amplitudes and muscle contraction timings. Muscle contraction timings were designated as premotor time, electromechanical delay and total reaction time. The effects of sex, age and their interactions on muscle properties were analyzed. Results: Women showed smaller torque amplitudes, longer electromechanical delay and longer total reaction time than men (P < 0.01), whereas no sex difference was observed in association with premotor time (P = 0.15). Age–sex interaction was significant in torque amplitudes and in electromechanical delay (P < 0.01). Post‐hoc test revealed that torque amplitude differed between sexes only in the young (P < 0.001). In contrast, the electromechanical delay differed between sexes only in the elderly and the age‐related elongation of electromechanical delay was significant only in women (P < 0.001). Conclusion: Both a sex difference and a sex difference of age‐related change in hip abductor muscle properties were demonstrated. These sex differences may contribute to the sex difference in lateral balance performance. Geriatr Gerontol Int 2011; 11: 333–340 . 相似文献
996.
997.
998.
Autofluorescence endoscopy is a promising functional imaging technique to improve screening of pre-cancerous or early cancer lesions in the gastrointestinal (GI) tract. Tissue autofluorescence signal is weak compared to white light reflectance imaging. Conventional forward-viewing endoscopes are inefficient in the collection of light from objects of interest along on the GI luminal wall. A key component of a complete autofluorescence endoscope is the light collection module. In this paper, we report the design, optimization, prototype development, and testing of an endoscope objective that is capable of acquiring simultaneous forward and radial views. The radial-view optical design was optimized for a balance between image quality and light collection. Modulation transfer function (MTF), entrance pupil radius, manufacturability, and field-of-view were parameters used in the lens optimization. In comparison with the typical forward-viewing endoscopes, our nonsequential ray trace simulations suggest the proposed radial-view design is more practical in the light collection. To validate the proposed simulation methods, a 3:1 scaled-up prototype was fabricated. Contrast measurements were taken with the prototype, and then compared with the simulated MTF. 相似文献
999.
1000.
Brian Chung Brooke Willis Poh‐San Lai 《American journal of medical genetics. Part C, Seminars in medical genetics》2019,181(2):150-154
This Special Issue on Clinical Genetics in Asia highlights a collection of articles showing the growth, development, and current status of clinical genetics in Asia. In this Introduction, the Guest Editors share on the themes of this issue to provide useful insights into the rapid growth of genomics and clinical genetics in this region. The contents of this Issue cover a range of topics from the history and development of clinical genetics in Asia to studies on disorders with clinical significance or phenotype differences in the Asian populations to the status of precision medicine. The goal is to provide a glimpse of how significantly the field of genetics in Asia has developed in recent years with the aspiration that this can serve as a catalyst to increase international collaboration and cooperation in combating genetic diseases. We hope that this issue shows Asia's readiness and willingness to be a part of more international conversations about genetics in future. 相似文献