全文获取类型
收费全文 | 5907篇 |
免费 | 519篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 183篇 |
妇产科学 | 100篇 |
基础医学 | 711篇 |
口腔科学 | 125篇 |
临床医学 | 773篇 |
内科学 | 809篇 |
皮肤病学 | 133篇 |
神经病学 | 669篇 |
特种医学 | 438篇 |
外科学 | 854篇 |
综合类 | 294篇 |
一般理论 | 2篇 |
预防医学 | 483篇 |
眼科学 | 105篇 |
药学 | 345篇 |
2篇 | |
中国医学 | 57篇 |
肿瘤学 | 332篇 |
出版年
2022年 | 42篇 |
2021年 | 79篇 |
2020年 | 63篇 |
2019年 | 54篇 |
2018年 | 72篇 |
2017年 | 55篇 |
2016年 | 53篇 |
2015年 | 85篇 |
2014年 | 124篇 |
2013年 | 182篇 |
2012年 | 224篇 |
2011年 | 229篇 |
2010年 | 184篇 |
2009年 | 188篇 |
2008年 | 224篇 |
2007年 | 255篇 |
2006年 | 271篇 |
2005年 | 246篇 |
2004年 | 198篇 |
2003年 | 197篇 |
2002年 | 173篇 |
2001年 | 160篇 |
2000年 | 161篇 |
1999年 | 144篇 |
1998年 | 129篇 |
1997年 | 125篇 |
1996年 | 124篇 |
1995年 | 117篇 |
1994年 | 75篇 |
1993年 | 79篇 |
1992年 | 122篇 |
1991年 | 117篇 |
1990年 | 147篇 |
1989年 | 140篇 |
1988年 | 138篇 |
1987年 | 142篇 |
1986年 | 109篇 |
1985年 | 130篇 |
1984年 | 89篇 |
1983年 | 84篇 |
1982年 | 58篇 |
1981年 | 51篇 |
1980年 | 43篇 |
1979年 | 52篇 |
1978年 | 58篇 |
1977年 | 42篇 |
1976年 | 42篇 |
1973年 | 39篇 |
1955年 | 42篇 |
1954年 | 35篇 |
排序方式: 共有6472条查询结果,搜索用时 15 毫秒
2.
Kimberly B. Glazer Kendrin R. Sonneville Nadia Micali Sonja A. Swanson Ross Crosby Nicholas J. Horton Kamryn T. Eddy Alison E. Field 《The Journal of adolescent health》2019,64(2):165-171
Purpose
To quantify eating disorder (ED) stability and diagnostic transition among a community-based sample of adolescents and young adult females in the United States.Methods
Using 11 prospective assessments from 9,031 U.S. females ages 9–15 years at baseline of the Growing Up Today Study, we classified cases of the following EDs involving bingeing and purging: bulimia nervosa (BN), binge ED, purging disorder (PD), and subthreshold variants defined by less frequent (monthly vs. weekly) bingeing and purging behaviors. We measured number of years symptomatic and probability of maintaining symptoms, crossing to another diagnosis, or resolving symptoms across consecutive surveys.Results
Study lifetime disorder prevalence was 2.1% for BN and roughly 6% each for binge ED and PD. Most cases reported symptoms during only one survey year. Twenty-six percent of cases crossed between diagnoses during follow-up. Among participants meeting full threshold diagnostic criteria, transition from BN was most prevalent, crossing most frequently from BN to PD (12.9% of BN cases). Within each disorder phenotype, 20%–40% of cases moved between subthreshold and full threshold criteria across consecutive surveys.Conclusions
Diagnostic crossover is not rare among adolescent and young adult females with an ED. Transition patterns from BN to PD add support for considering these classifications in the same diagnostic category of disorders that involve purging. The prevalence of crossover between monthly and weekly symptom frequency suggests that a continuum or staging approach may increase utility of ED classification for prognostic and therapeutic intervention. 相似文献3.
4.
Dr. Arni Raghavendrarao Raghuram M.Ch. Subbiah Kumar MD Kathamuthu Balamurugan DA Arulmurugan DA Ramiah Krishnan M.Ch. Perichiappan Sivakami BS Eluvathingal Varghese John M.Ch. 《Indian Journal of Thoracic and Cardiovascular Surgery》2006,22(3):178-181
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country.
It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS)
with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery
(OPCAB) in patients with critical left main stem stenosis.
Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During
the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the
same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution
was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively.
10 patients were high risk with a Euro score of ≥5.
Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation
time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding.
There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion
to CPB. There was no operative mortality. Inotropes were used in ten cases.
Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic
shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or
Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may
be managed by Beating heart On Pump (BHOP) technique. 相似文献
5.
6.
7.
8.
The recent development of brain atlases with computer graphics templates, and of huge databases of neurohistochemical data on the internet, has forced a systematic re-examination of errors associated with comparing histological features between adjacent sections of the same brain, between brains treated in the same way, and between brains from groups treated in different ways. The long-term goal is to compare as accurately as possible a broad array of data from experimental brains within the framework of reference atlases. Main sources of error, each of which ideally should be measured and minimized, include intrinsic biological variation, linear and nonlinear distortion of histological sections, plane of section differences between each brain, section alignment problems, and sampling errors. These variables are discussed, along with approaches to error estimation and minimization in terms of a specific example—the distribution of neuroendocrine neurons in the rat paraventricular nucleus. Based on the strategy developed here, the main conclusion is that the best long-term solution is a high-resolution 3D computer graphics model of the brain that can be sliced in any plane and used as the framework for quantitative neuroanatomy, databases, knowledge management systems, and structure–function modeling. However, any approach to the automatic annotation of neuroanatomical data—relating its spatial distribution to a reference atlas—should deal systematically with these sources of error, which reduce localization reliability. 相似文献
9.
10.