全文获取类型
收费全文 | 2991篇 |
免费 | 183篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 67篇 |
妇产科学 | 77篇 |
基础医学 | 329篇 |
口腔科学 | 61篇 |
临床医学 | 235篇 |
内科学 | 673篇 |
皮肤病学 | 47篇 |
神经病学 | 102篇 |
特种医学 | 192篇 |
外科学 | 374篇 |
综合类 | 232篇 |
一般理论 | 3篇 |
预防医学 | 194篇 |
眼科学 | 303篇 |
药学 | 125篇 |
中国医学 | 1篇 |
肿瘤学 | 173篇 |
出版年
2023年 | 26篇 |
2022年 | 47篇 |
2021年 | 99篇 |
2020年 | 42篇 |
2019年 | 62篇 |
2018年 | 68篇 |
2017年 | 45篇 |
2016年 | 64篇 |
2015年 | 60篇 |
2014年 | 94篇 |
2013年 | 119篇 |
2012年 | 134篇 |
2011年 | 144篇 |
2010年 | 89篇 |
2009年 | 82篇 |
2008年 | 148篇 |
2007年 | 140篇 |
2006年 | 120篇 |
2005年 | 140篇 |
2004年 | 118篇 |
2003年 | 115篇 |
2002年 | 108篇 |
2001年 | 115篇 |
2000年 | 100篇 |
1999年 | 89篇 |
1998年 | 46篇 |
1997年 | 34篇 |
1996年 | 40篇 |
1995年 | 29篇 |
1994年 | 24篇 |
1993年 | 21篇 |
1992年 | 40篇 |
1991年 | 46篇 |
1990年 | 42篇 |
1989年 | 39篇 |
1988年 | 49篇 |
1987年 | 36篇 |
1986年 | 28篇 |
1985年 | 29篇 |
1983年 | 20篇 |
1982年 | 18篇 |
1979年 | 15篇 |
1978年 | 17篇 |
1976年 | 17篇 |
1972年 | 14篇 |
1959年 | 16篇 |
1958年 | 16篇 |
1957年 | 14篇 |
1955年 | 15篇 |
1954年 | 19篇 |
排序方式: 共有3201条查询结果,搜索用时 15 毫秒
41.
Maberley DA Yannuzzi LA Gitter K Singerman L Chew E Freund KB Noguiera F Sallas D Willson R Tillocco K 《Ophthalmology》1999,106(12):2248-52; discussion 2252-3
Objective
To examine the association between previous radiation exposure and idiopathic perifoveal telangiectasis (IPT).Design
A multicentered, individually matched, case-control study design was used.Participants/controls
Sixty-five case subjects were matched with 175 control subjects. Individuals with unequivocal evidence of angiographically confirmed IPT were included as cases. Control subjects were matched for center, age, and gender.Main outcome measure
The main exposures of interest were a history of therapeutic head or neck irradiation and environmental radiation exposure.Methods
A standardized questionnaire was administered to case and control subjects. Data were collected for the main exposures of interest as well as pertinent covariates. Conditional logistic regression was used to evaluate therapeutic and environmental radiation as risks for IPT.Results
On univariate analysis, head or neck irradiation was associated with IPT (odds ratios [OR] = 4.15, 95% confidence interval [CI] = 1.30–13.24). While controlling for diabetes and family history of diabetes, IPT was found to be associated with both head or neck irradiation (OR = 4.06, 95% CI = 1.20–13.76) and with environmental irradiation (OR = 6.73, 95% CI = 1.06–42.74).Conclusions
This study presents a previously unreported association between prior radiation exposure and IPT. 相似文献42.
Anterior segment optical coherence tomography imaging of trabeculectomy blebs before and after laser suture lysis 总被引:1,自引:0,他引:1
Singh M Aung T Friedman DS Zheng C Foster PJ Nolan WP See JL Smith SD Chew PT 《American journal of ophthalmology》2007,143(5):873-875
PURPOSE: To image trabeculectomy blebs before and after laser suture lysis (LSL) using anterior segment optical coherence tomography (AS-OCT). DESIGN: Prospective observational study. METHODS: Blebs were imaged with a prototype of the AS-OCT (Carl Zeiss Meditec, Inc, Dublin, California, USA) before and after LSL. Blebs were assessed for bleb height, bleb wall thickness, apposition of the scleral flap to sclera, and patency of the internal ostium. RESULTS: Seven blebs in eyes of seven patients were imaged. Pre-LSL, five blebs were low and two were of moderate height. After LSL, six of seven eyes (85.7%) showed an increase in total bleb height, with increased bleb wall thickness and separation of the scleral flap from sclera. In one eye, there was no discernible change in bleb height, cavity height, or wall thickness. CONCLUSIONS: AS-OCT was able to demonstrate features of bleb morphology that changed after LSL. 相似文献
43.
How AC Aung T Chew X Yong VH Lim MC Lee KY Toh JY Li Y Liu J Vithana EN 《Investigative ophthalmology & visual science》2007,48(5):2123-2126
PURPOSE: A recent study identified single nucleotide polymorphisms (SNPs) within the IL-1 gene cluster at chromosomal locus 2q13 that were associated with reduced risk for primary open-angle glaucoma (POAG) in whites. The purpose of this study was to investigate the association between IL-1 SNPs and glaucoma in Chinese patients with either POAG or primary-angle closure glaucoma (PACG). METHODS: Patients with POAG with a mean IOP without treatment that was consistently <21 mm Hg on diurnal testing were classified as having normal-tension glaucoma (NTG) and those with higher IOP were classified as having high-tension glaucoma (HTG). Subjects with PACG had at least 180 degrees of angle closure on gonioscopy. Genotypes were determined by polymerase chain reaction and restriction digest enzymes at the following loci: IL1A (-889C/T), IL1B (+3953C/T), and IL1B (-511C/T). The association of individual SNPs with glaucoma was evaluated by using chi(2) testing. Haplotype analysis was performed with the PHASE program, with haplotype frequency estimated for combined cases and controls, assuming Hardy-Weinberg equilibrium (HWE) of haplotypes. RESULTS: Of the Chinese subjects studies, 194 had POAG (94 NTG and 100 HTG), 125 had PACG, and 79 were normal control subjects. There was no significant difference in IL-1 SNP or allele frequencies for in subjects with POAG or PACG compared with control subjects, or between NTG and HTG. None of the common haplotypes showed any significant difference between the HTG, NTG, PACG, and normal control subjects. CONCLUSIONS: This study did not find an association between IL-1 gene cluster polymorphisms and glaucoma in this sample of Chinese subjects. 相似文献
44.
Nutritional supplementation in age-related macular degeneration 总被引:3,自引:0,他引:3
PURPOSE OF REVIEW: This review assesses the current status of the knowledge of the role of nutrition in age-related macular degeneration - a leading cause of vision loss in the persons with European ancestry. RECENT FINDINGS: We will evaluate the different nutritional factors and both observational and interventional studies used to assess the association of nutrition with age-related macular degeneration. Persons with intermediate risk of age-related macular degeneration or advanced age-related macular degeneration in one eye are recommended to take the formulation proven in the Age-Related Eye Disease Study (AREDS) to be successful in preventing the development of advanced age-related macular degeneration by 25%. The formulation consists of vitamins C, E, beta-carotene and zinc. In addition, observational data suggest that high dietary intake of macular xanthophylls lutein and zeaxanthin are associated with a lower risk of advanced age-related macular degeneration. Similarly, long-chain polyunsaturated fatty acids derived from fish consumption are also associated with a decreased risk of advanced age-related macular degeneration. SUMMARY: Persons with intermediate age-related macular degeneration or advanced age-related macular degeneration (neovascular or central geographic atrophy) in one eye should consider taking the AREDS-type supplements. Further evaluation of nutritional factors, specifically, lutein/zeaxanthin and omega-3 fatty acids will be tested in a multicenter controlled, randomized trial - the Age-Related Eye Disease Study 2 (AREDS2). 相似文献
45.
Four imaging examinations-gallium citrate Ga 67 scintigraphy, liver-spleen scans, lymphangiography, and computed tomography-were used in the initial staging of mycosis fungoides and Sézary syndrome in 62 patients (85% with stage I or II disease). None of the imaging modalities added significantly to the information already available from physical examinations and routinely performed lymph node biopsies. The results of this investigation did not support routine performance of imaging studies in patients with early stages of cutaneous T-cell lymphoma. 相似文献
46.
Hong Chee Chew Arjun Iyer Mark Connellan Sarah Scheuer Jeanette Villanueva Ling Gao Mark Hicks Michelle Harkness Claudio Soto Andrew Dinale Priya Nair Alasdair Watson Emily Granger Paul Jansz Kavitha Muthiah Andrew Jabbour Eugene Kotlyar Anne Keogh Kumud Dhital 《Journal of the American College of Cardiology》2019,73(12):1447-1459
Background
Transplantation of hearts retrieved from donation after circulatory death (DCD) donors is an evolving clinical practice.Objectives
The purpose of this study is to provide an update on the authors’ Australian clinical program and discuss lessons learned since performing the world’s first series of distantly procured DCD heart transplants.Methods
The authors report their experience of 23 DCD heart transplants from 45 DCD donor referrals since 2014. Donor details were collected using electronic donor records (Donate Life, Australia) and all recipient details were collected from clinical notes and electronic databases at St. Vincent’s Hospital.Results
Hearts were retrieved from 33 of 45 DCD donors. A total of 12 donors did not progress to circulatory arrest within the pre-specified timeframe. Eight hearts failed to meet viability criteria during normothermic machine perfusion, and 2 hearts were declined due to machine malfunction. A total of 23 hearts were transplanted between July 2014 and April 2018. All recipients had successful implantation, with mechanical circulatory support utilized in 9 cases. One case requiring extracorporeal membrane oxygenation subsequently died on the sixth post-operative day, representing a mortality of 4.4% over 4 years with a total follow-up period of 15,500 days for the entire cohort. All surviving recipients had normal cardiac function on echocardiogram and no evidence of acute rejection on discharge. All surviving patients remain in New York Heart Association functional class I with normal biventricular function.Conclusions
DCD heart transplant outcomes are excellent. Despite a higher requirement for mechanical circulatory support for delayed graft function, primarily in recipients with ventricular assist device support, overall survival and rejection episodes are comparable to outcomes from contemporary brain-dead donors. 相似文献47.
48.
49.
50.
Victor Koh Janina Tatsios Paul T K Chew Shantha Amrith 《Indian journal of ophthalmology》2015,63(12):895-898
Objective:To compare the incidence of upper eyelid blepharoptosis after combined phacotrabeculectomy with mitomycin C and phacoemulsification surgeries and the relationship of bleb morphology to the incidence of ptosis.Design:Retrospective observation study.Participants:We included 46 patients after combined phacotrabeculectomy and 44 patients with phacoemulsification in the former group, and all eyes underwent a standardized two-site surgery with intra-operative mitomycin C.Results:There were 8 eyes (17.4%) and 5 eyes (11.4%) with postoperative ptosis in the phacotrabeculectomy and phacoemulsification groups, respectively (P = 0.342). In multivariate regression analysis, reduced total bleb area was significantly associated with upper eyelid ptosis after adjusting for age, gender, and type of anesthesia. The trend seemed to show that increased bleb height was also associated with ptosis, but this did not reach statistical significance.Conclusions:Incidence of persistent ptosis after phacoemulsification combined with trabeculectomy and mitomycin C is similar compared to stand alone phacoemulsification surgery in a multiethnic Asian population. Bleb morphology may play an important role in postoperative ptosis development and should be considered in the evaluation of upper eyelid blepharoptosis. 相似文献