全文获取类型
收费全文 | 1455275篇 |
免费 | 118881篇 |
国内免费 | 7439篇 |
专业分类
耳鼻咽喉 | 18541篇 |
儿科学 | 44779篇 |
妇产科学 | 38317篇 |
基础医学 | 202182篇 |
口腔科学 | 39223篇 |
临床医学 | 131572篇 |
内科学 | 299102篇 |
皮肤病学 | 35674篇 |
神经病学 | 119923篇 |
特种医学 | 62192篇 |
外国民族医学 | 274篇 |
外科学 | 225060篇 |
综合类 | 32051篇 |
现状与发展 | 5篇 |
一般理论 | 439篇 |
预防医学 | 112918篇 |
眼科学 | 31157篇 |
药学 | 104395篇 |
5篇 | |
中国医学 | 3634篇 |
肿瘤学 | 80152篇 |
出版年
2021年 | 12883篇 |
2019年 | 11845篇 |
2018年 | 16834篇 |
2017年 | 13398篇 |
2016年 | 16475篇 |
2015年 | 19503篇 |
2014年 | 26052篇 |
2013年 | 36822篇 |
2012年 | 46888篇 |
2011年 | 49122篇 |
2010年 | 30241篇 |
2009年 | 28901篇 |
2008年 | 43466篇 |
2007年 | 45450篇 |
2006年 | 45897篇 |
2005年 | 44071篇 |
2004年 | 41591篇 |
2003年 | 40038篇 |
2002年 | 37460篇 |
2001年 | 68175篇 |
2000年 | 69863篇 |
1999年 | 58131篇 |
1998年 | 17499篇 |
1997年 | 15577篇 |
1996年 | 16427篇 |
1995年 | 16600篇 |
1994年 | 15414篇 |
1993年 | 14419篇 |
1992年 | 47679篇 |
1991年 | 46269篇 |
1990年 | 44450篇 |
1989年 | 42234篇 |
1988年 | 39105篇 |
1987年 | 38424篇 |
1986年 | 36120篇 |
1985年 | 34915篇 |
1984年 | 26554篇 |
1983年 | 22264篇 |
1982年 | 13941篇 |
1981年 | 12578篇 |
1979年 | 23709篇 |
1978年 | 17197篇 |
1977年 | 14475篇 |
1976年 | 13291篇 |
1975年 | 13829篇 |
1974年 | 16209篇 |
1973年 | 15488篇 |
1972年 | 14257篇 |
1971年 | 13104篇 |
1970年 | 11939篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
M. R. D. Maslin S. K. Lloyd S. Rutherford S. Freeman A. King D. R. Moore K. J. Munro 《Journal of the Association for Research in Otolaryngology》2015,16(5):631-640
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis. 相似文献
5.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments. 相似文献
6.
7.
Haya Mohammed BSc MChB M. Yousuf Salmasi MRCS Massimo Caputo PhD Gianni D. Angelini PhD Hunaid A. Vohra PhD 《Journal of cardiac surgery》2020,35(6):1209-1219
Background
Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.Methods
PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.Results
Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.Conclusions
MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.8.
Andrea Stracciolini Jennifer Luz Gregory Walker Nicholas M. Edwards Avery D. Faigenbaum Gregory D. Myer 《The Physician and sportsmedicine》2020,48(2):199-207
ABSTRACT
Objective
To investigate primary care physician clinical practice patterns, barriers, and education surrounding pediatric physical activity (PA), and to compare practice patterns by discipline. 相似文献9.
Comparative outcomes of vascular access in patients older than 70 years with end-stage renal disease
Deokbi Hwang Sujin Park Hyung-Kee Kim Seung Huh 《Journal of vascular surgery》2019,69(4):1196-1206.e5
Objective
The advantage of arteriovenous fistulas (AVFs) in older patients requiring dialysis is controversial. We reviewed our vascular access experience in patients ≥70 years of age (older group) compared with younger patients.Methods
We analyzed consecutive patients who underwent access surgery between 2013 and 2016. Primary success (PS) and primary patency (PP) data were analyzed between the older and younger groups before and after propensity score matching of the patients' characteristics and access composition. PS was defined as the achievement of access function that was amenable to two sessions of successful cannulation without early occlusion or maturation failure requiring revision. PP was defined as the time with uninterrupted patency without intervention.Results
A total of 594 consecutive accesses were created among 563 patients, of whom 119 were allocated into each group after propensity score matching. In the whole cohort, 193 accesses (32.5%) were performed in older patients. AVFs were performed in 130 (67.4%) older patients and 293 (73.1%) younger patients. Regarding AVFs, the PS rate (83.6% in the older group vs 94.3% in the younger group; P = .001) and the overall PP at 6 and 12 months (73.1% and 57.1%, respectively, in the older group vs 86.7% and 77.7%, respectively, in the younger group; P = .009) were lower in the older group than in the younger group. However, no differences were found in the PS and PP rates for arteriovenous grafts between groups. Regarding the AVF location, the PS rate for forearm AVFs was significantly lower in the older group than in the younger group (76% vs 93%; P < .001); however, the PS rate of the upper arm was not different between the groups (94% vs 97%; P = .425). In the patients with PS, the PP rate of AVFs was similar between the two groups. In the older group with forearm AVFs, the median diameter of the radial artery was larger in the patients with PS than in the patients without PS (2.20 mm with PS vs 2.00 mm without PS; P = .008). The propensity score matching results demonstrated similar trends for the whole cohort, with lower PS (P = .042) and PP rates (P = .023) for AVF in the older group.Conclusions
The outcomes after AVF were poorer in the older group than in the younger group, which was primarily due to unsatisfactory outcomes in patients with forearm AVFs. Thus, stricter criteria, especially regarding the radial artery diameter, should be applied for forearm AVFs in older patients, and additional research is necessary to delineate the risk factors for primary failure. 相似文献10.
Clint R. Bellenger John B. Arnold Jonathan D. Buckley Dominic Thewlis Joel T. Fuller 《Journal of Science and Medicine in Sport》2019,22(3):294-299