全文获取类型
收费全文 | 1041篇 |
免费 | 84篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 2篇 |
基础医学 | 26篇 |
口腔科学 | 2篇 |
临床医学 | 29篇 |
内科学 | 5篇 |
皮肤病学 | 6篇 |
神经病学 | 2篇 |
特种医学 | 8篇 |
外科学 | 7篇 |
综合类 | 92篇 |
预防医学 | 16篇 |
眼科学 | 914篇 |
药学 | 18篇 |
中国医学 | 1篇 |
肿瘤学 | 3篇 |
出版年
2024年 | 3篇 |
2023年 | 20篇 |
2022年 | 22篇 |
2021年 | 30篇 |
2020年 | 31篇 |
2019年 | 24篇 |
2018年 | 34篇 |
2017年 | 48篇 |
2016年 | 32篇 |
2015年 | 39篇 |
2014年 | 59篇 |
2013年 | 58篇 |
2012年 | 59篇 |
2011年 | 60篇 |
2010年 | 44篇 |
2009年 | 36篇 |
2008年 | 34篇 |
2007年 | 53篇 |
2006年 | 52篇 |
2005年 | 30篇 |
2004年 | 28篇 |
2003年 | 37篇 |
2002年 | 29篇 |
2001年 | 28篇 |
2000年 | 29篇 |
1999年 | 20篇 |
1998年 | 14篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 6篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 18篇 |
1982年 | 6篇 |
1981年 | 13篇 |
1980年 | 10篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有1135条查询结果,搜索用时 18 毫秒
1.
The calculation of the extent of the ring scotoma around positive lenses, as conventionally taught to students of clinical optics, indicates that the scotoma is of a significant size. Using knife-edge lenses this study shows that the calculations are invalid due to the finite size of the eye's entrance pupil and in many instances the scotoma is shown not to exist. The effect noticed in clinical practice is probably largely due to the frame and the edging techniques used which add to the refractive scotoma which is present with high powered lenses, large apertures and/or small pupil sizes. 相似文献
2.
白内障超声乳化吸出及囊袋内人工晶体植入术 总被引:1,自引:0,他引:1
为观察和评价超声乳化白内障吸出术的临床效果、特点、并发病及防治措施,对41 眼白内障施行超声乳化吸出术及小切口(6mm)囊袋内人工晶体植入术,并以同期的白内障患者41眼行现代囊外摘除及后房型人工晶体植入做对照。结果:术后6个月,视力≥1.0者占43.9%>0.8者占70.7≥0.5者占92.7%,均明显高于对照组(P<0.001),术后平均散光为1.04±0.81,1,低于对照组(P<0.01)。白内障超声乳化吸出并囊袋内人工晶体植入术的复明效果优于囊外摘除并后房型人工晶体植入术。 相似文献
3.
Background: This study was conducted to investigate grading performance when estimating the severity of static versus dynamic images of contact lens‐related ocular pathology. Methods: Thirty‐eight subjects used the Efron Grading Scales for Contact Lens Complications to grade the severity of ocular pathological changes depicted in static and dynamic (movie clip) computer‐displayed images of each of the following contact lens complications: bulbar conjunctival redness, limbal redness, papillary conjunctivitis, corneal staining, corneal infiltrates and meibomian gland dysfunction. The viewing of static and dynamic images was separated by seven weeks. Results: Grades assigned to dynamic images were 0.6 and 0.7 grading scale units higher than those assigned to static images for limbal redness and papillary conjunctivitis, respectively (p < 0.0001 for both). No difference was observed for the other four complications. There was an apparent trend for grading variability to be reduced (that is, observers grading in closer agreement) when grading dynamic versus static images. Conclusions: Absolute grades based on an assessment of signs of pathology represented in static images may, in some instances, underestimate the true severity of the condition. 相似文献
4.
观察50例长期配戴亲水性角膜接触镜者戴镜前后SchirmerI试验和泪膜破裂时间(BUT)的变化。结果表明,戴接触镜后BUT缩短,SchirmerI下降,双眼BUT与SchirmerI之间无相关性。讨论了引起泪膜流动和BUT改变的机制。 相似文献
5.
G Smith 《Clinical & experimental optometry》1992,75(1):27-34
The spherical aberration of eyes corrected with intra-ocular lenses is investigated using a model eye with realistic levels of corneal asphericity. The results indicate that the aberration is intermediate between that of paraxial schematic eyes and real eyes. By using standard optical aberration theory, it is shown that for a plano-convex lens with the curved surface facing the cornea, the aberration is similar to that of normal phakic eyes and therefore probably too low to be of any clinical significance. However, for other lens orientations or designs, the level of aberration is usually higher and may lead to a refractive error varying with pupil size and a loss of acuity with large pupil diameters. 相似文献
6.
概述光学塑料的基本材料,讨论塑料镜片材料的主要品种及其应用,并着重分析影响塑料镜片材料性能的主要因素及其发展趋势。 相似文献
7.
The adhesion to hydrogel contact lenses and growth of Serratia marcescens on artificial tear fluid (ATF) soaked lenses was investigated. Results indicated that a corneal ulcer isolate adhered more avidly to lenses; ATF increased adhesion for all strains tested. The contact lens induced acute red eye (CLARE) isolate adhered poorly; however; it grew to a larger extent on ATF-coated lenses. The ability of the corneal ulcer isolate to adhere to lenses may be an important factor in its pathogenicity whereas the ability of the CLARE isolate to grow on the lens in the presence of antimicrobial tear proteins may be important in the development of inflammation. 相似文献
8.
Raul Martin 《Clinical & experimental optometry》2007,90(1):26-30
Background: There are many contact lens‐related ocular surface disorders. Some can damage the limbal region where stem cells are thought to be located in its basal cell layer. This damage can result in destruction and a deficiency of corneal stem cells. One important sign of this complication is corneal conjunctivalisation. The purpose of this study is to describe clinical characteristics of a series of long‐standing contact lens (CL) wearers with corneal conjunctivalisation (CC). Methods: In a one‐year (March 2004 to March 2005) retrospective unmasked study, 591 CL clinical histories (195 new patients and 396 review patients) were analysed. Results: There were 24 eyes of 14 myopic patients (93 per cent women) with CC without a specific disease entity known to cause limbal stem cell deficiency (LSCD). Conjunctivalisation occurred in the inferior limbus of three eyes (12 per cent). Only four patients (28.6 per cent) reported previous ocular symptoms. All were myopic with a mean spherical equivalent of ‐8.80 ± 5.00 (SD) dioptres (range from ‐1.75 to ‐21.50 D) and mean visual acuity 0.9 ± 0.2 (range from 0.4 to 1.2). The mean years of CL wear was 17.6 ± 8.5 (CI 95% 13.2 to 22; range six to 30). All were daily‐wear patients with a mean daily‐wear time of 12.5 ± 1.8 hours per day (CI 95% 11.6 to 13.4). Conclusion: Corneal conjunctivalisation is a contact lens‐related complication in asymptomatic patients. Optometrists can play an important role in early diagnosis, education and management of these patients. 相似文献
9.
Sverker Norrby 《Ophthalmic & physiological optics》2005,25(2):153-161
Dubbelman and co-workers have determined intraocular spacings and surface shapes in living eyes by means of corrected Scheimpflug images in a large number of subjects of different age at several levels of accommodation. They give relationships for key anterior segment parameters as a function of age and level of accommodation. These are used in this paper to build a schematic eye incorporating aspheric surfaces. This eye model is analysed by means of ray tracing with a technique developed for use with a common spreadsheet computer program. The Dubbelman eye model appears to be well corrected for spherical aberration. Compared with measurements on real eyes it agrees well in general, but spherical aberration is negative, while in real eyes it tends to be positive. 相似文献
10.
Gavin F. Bridgman 《Clinical & experimental optometry》1989,72(3):91-93
An infant rod monochromat was diagnosed and was then treated with the Younger PLS 550 lens. The comparison in use of PLS 550 and a neutral density lens confirmed the presence of cone dysfunction. The use of this lens takes advantage of the spectral shift in luminosity between rods and cones. Younger PLS 550 and PLS 530 tints are used for the relief of photophobia according to prevailing brightness. This paper discusses patient management with the use of these lenses and some characteristics of the vision of a rod monochromat. 相似文献