Prevalence and risk factors of lens opacities in rural populations living at two different altitudes in China

AIM： To investigate the prevalence of and risk factors for lens opacities in populations living at two different altitudes in China.·METHODS： A total of 813 subjects aged ≥40y in Lhasa（Tibet Autonomous Region, China. Altitude： 3658 m） and Shaoxing（Zhejiang Province, China. Altitude： 15 m） were underwent eye examinations and interviewed in this cross-sectional study. Participants＇ lens opacities were graded according to the Lens Opacities Classification System II（LOCS II） and the types of opacities with LOCS II scores ≥2 were determined. Univariate and stepwise logistic regression were used to evaluate the associations of independent risk factors with lens opacities.· RESULTS： Lens opacities were significantly more prevalent in the high-altitude than in the low-altitude area（χ2=10.54, P 〈0.001）. Lens opacities appear to develop earlier in people living at high than at low altitude. The main types of lens opacity in Lhasa and Shaoxing were mixed（23.81%） and cortical（17.87%）,respectively. Independent risk factors associated with all lens opacities were age, ultraviolet（UV） radiation exposure,and educational level. Compared with participants aged40-49 y, the risk of lens opacities increased gradually from 2 to 85 times per 10 y [odds ratio（OR）=2.168-84.731,P 〈0.05）. The risk of lens opacities was about two times greater in participants with the highest UV exposure than in those with the lowest exposure（OR=2.606, P =0.001）.Educational level was inversely associated with lensopacities; literacy deceased the risk by about 25%compared with illiteracy（OR=0.758, P =0.041）.·CONCLUSION： Old age, higher UV exposure and lower educational level are important risk factors for the development of lens opacities. Lens opacities are more prevalent among high-altitude than low-altitude inhabitants.

Molecular opacities of low-lying states of oxygen molecule

The X^3Σg^-,A^'3△u,A^3Σ^u+,1^3Πg,and B^3Σu^-electronic states of oxygen molecule(O2)are calculated by the multiconfiguration self-consisted filed(MRCI)+Q method with the scalar relativistic correction and core-valence correlation correction.The obtained spectroscopic constants of the low-lying bound states are in excellent agreement with measurements.Based on the accurately calculated structure parameters,the opacities of the oxygen molecule at the temperatures of 1000 K,2000 K,2500 K,and 5000 K under a pressure of 100 atm(1 atm=1.01325×10^5 Pa)and the partition functions between 10 K and 10^4 K are obtained.It is found that with the increase of temperature,the opacities for transitions in a long wavelength range are enlarged because of the larger population on excited electronic states at the higher temperatures.

Penetrating keratoplasty in children under 3 years old with congenital corneal opacities

AIM:To evaluate the graft rejection and visual outcomes after penetrating keratoplasty(PK)in the presence of various congenital corneal opacities in children.METHODS:In this retrospective cohort study,children who underwent PK were then followed for 5 y.The patient’s medical records were collected from June 2014 until June 2019 and analyzed in December 2019.All patients were children under three years old with congenital corneal opacities with or without microcornea who came to a pediatric ophthalmologist and underwent PK in Jakarta Eye Center(JEC).Beforehand,all children have participated in a thorough evaluation for PK.In the case of severe microcornea was not advised to undergo surgery.The visual outcomes and graft survival rate were described in percentages.The graft survival plot was presented with Kaplan-Meier,while the visual acuity was analyzed using the Wilcoxon signed ranks test.RESULTS:Sixteen eyes from eleven patients(seven girls and four boys)underwent PK.The graft survival rate of the first 6,12,and 18 mo later of keratoplasty was 100%,83.3%,and 66.7%,respectively.The overall mean survival time is 22 mo(standard error 2.419),and no significant difference between the patients underwent PK before and after 36 mo of their age(P=0.52).The graft failure was 50%,and postsurgery complications included cataract 43.7%,band keratopathy 12.5%,and scleromalasia 6.25%.Wilcoxon test analysis of visual acuity post keratoplasty was not statistically significant(P=0.34),while overall showed 44%improvements of visual outcome for 5 y of follow-up.With a good survival at one year up to 22 mo(83.3%),the visual acuity could be achieved(63%),and showed improvements(44%)during follow-up.CONCLUSION:The complications are frequent for pediatric PK.Thus,corneal surgery on infants requires careful case selection,adequate pre-operative evaluation,skilled surgery(optical correction),very close cooperation family–physician,intensive post-operation care,and amblyopia management in the future.

Phacoemulsification in eyes with corneal opacities after deep anterior lamellar keratoplasty

To evaluate the maneuverability and efficacy of phacoemulsification and intraocular lens(IOL) implantation in eyes with corneal opacities after deep anterior lamellar keratoplasty(DALK), twelve eyes of 12 patients with mild to moderate corneal opacities after DALK and coexisting cataracts were analyzed retrospectively. Phacoemulsification and IOL implantation assisted with anterior capsule staining, as well as non-invasive optical fiber illumination, were performed on all eyes. No intraoperative or postoperative complications were noted. Mean corrected distance visual acuity(logMAR) improved from 1.24±0.17 to 0.73±0.22. Post-phaco intraocular pressure was maintained between 13 to 20 mm Hg in all cases throughout the follow-up period. Mean endothelial cell density decreased from 2258.42±205.94 to 1906.25±174.23 cells/mm2. Phacoemulsification and IOL implantation are safe and valid in eyes with mild to moderate corneal opacities after DALK and coexisting cataracts when assisted with anterior capsule staining and non-invasive optical fiber illumination.

Molecule opacities of X^2Σ^+, A^2Π, and B^2Σ^+ states of CS^+

Carbon sulfide cation(CS^+) plays a dominant role in some astrophysical atmosphere environments. In this work, the rovibrational transition lines are computed for the lowest three electronic states, in which the internally contracted multireference configuration interaction approach(MRCI) with Davison size-extensivity correction(+Q) is employed to calculate the potential curves and dipole moments, and then the vibrational energies and spectroscopic constants are extracted. The Frank–Condon factors are calculated for the bands of X^2^+Σ^+–A^2Π and X^2Σ^+–B^2Σ^+systems, and the band of X^2Σ^+–A^2Π is in good agreement with the available experimental results. Transition dipole moments and the radiative lifetimes of the low-lying three states are evaluated. The opacities of the CS^+ molecule are computed at different temperatures under the pressure of 100 atms. It is found that as temperature increases, the band systems associated with different transitions for the three states become dim because of the increased population on the vibrational states and excited electronic states at high temperature.

数“智”赋能图书馆为资源整合插上“数字翅膀”

在数字化转型的背景下,公共图书馆成为具有权威性和示范性的公共资源获取中心。公共图书馆通过数字资源整合能够促进资源共享,缩小城乡文化差距,实现城乡文化融合发展。现探讨适合唐山市公共图书馆数字资源整合的路径,包括通过OPAC实现传统馆藏资源的整合;通过集成检索系统实现数字资源整合;通过OPAC元数据和各种数字资源元数据的整合,以实现书目数据与电子资源数据的融合和呈现以及一站式检索,为城乡文化的融合发展提供丰富的资源。

Correlation between contrast sensitivity and the lens opacities classification system III in age-related nuclear and cortical cataracts

Background Contrast sensitivity （CS） testing can detect differences in functional vision and is highly correlated with visual performance. This study was designed to investigate the association between CS and the grading score using the lens opacities classification system （LOCS） III as well as the association between CS and visual acuity （VA） in nuclear or cortical age-related cataract （ARC） patients. Methods A total of 270 eyes with ARC and 30 control eyes were divided into nuclear opacity （NO）, nuclear color （NC）, cortical cataract （C） based on LOCS II1. The CS values measured at all spatial frequencies under photopic and glare conditions that resulted in contrast sensitivity function （CSF） were evaluated, and LogMAR VA was tested with the Early Treatment Diabetic Retinopathy Study （ETDRS） chart. The correlation between CSF and LOCS III grading scores, and between CSF and LogMAR VA were analyzed. Results Compared to the controls, CSF of the nuclear or cortical ARC significantly declined. There are significant correlation between CSF and LogMAR VA, and between CSF and LOCS III grading scores. Compared to the VA, a stronger correlation existed between CSF and LOCS III grading score than that of LogMAR VA and LOCS III grading score. CS at some spatial frequencies is significantly influenced with LOCS III grading score. Conclusions CSF significantly declined with the increasing ARC grading scores. Comparing to VA, CSF reflected the severity of cataract more comprehensively. CS at low spatial frequency is significantly influenced by ARC. Therefore, CS is more precise than VA in assessing the visual function of ARC patients.

Spectroscopy and molecule opacity investigation on excited states of SiS

The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molecular structure of SiS is limited.To obtain accurate information about the structure of its excited states,the high-precision multireference configuration interaction(MRCI)method has been utilized.This method is used to calculate the potential energy curves(PECs)of the 18Λ–S states corresponding to the lowest dissociation limit of SiS.The core–valence correlation effect,Davidson’s correction and the scalar relativistic effect are also included to guarantee the precision of the MRCI calculation.Based on the calculated PECs,the spectroscopic constants of quasi-bound and bound electronic states are calculated and they are in accordance with previous experimental results.The transition dipole moments(TDMs)and dipole moments(DMs)are determined by the MRCI method.In addition,the abrupt variations of the DMs for the 1^(5)Σ^(+)and 2^(5)Σ^(+)states at the avoided crossing point are attributed to the variation of the electronic configuration.The opacity of SiS at a pressure of 100 atms is presented across a series of temperatures.With increasing temperature,the expanding population of excited states blurs the band boundaries.

读者中文图书荐购数据分析及启示——以重庆图书馆为例

本文以重庆图书馆近八年的读者荐购数据为基础,对荐购信息进行了统计分析及实例对比,并对今后的资源建设提出了相应的建议及解决方案。

Small incision lenticule extraction and femtosecond-assisted laser in situ keratomileusis in patients with deep corneal opacity:case series

AIM:To report the safety,efficacy,and accuracy of small-incision lenticule extraction(SMILE)or femtosecondassisted laser in situ keratomileusis(FS-LASIK)for the correction of myopia or myopic astigmatism in patients with deep corneal opacity denoted by anterior segment optical coherence tomography(AS-OCT).METHODS:Four patients with monocular corneal opacity(3 due to mechanical injury,1 due to a firecracker wound)were recruited and treated with refractive surgery(3 for SMILE,1 for FS-LASIK combined with limbal relaxing incision(LRI).Preoperative ocular manifestations,surgical details,postoperative visual outcomes,corneal opacity parameters,and corneal topography were analyzed.RESULTS:Preoperatively,spherical diopter ranged from-3.0 D to-4.75 D with cylinder ranging from-0.75 to-5.0 D,and corrected distance visual acuity(CDVA)ranging from 20/25 to 20/20.One eye’s corneal opacity was located in the central zone and three were in the mid-peripheral optical zone.Three patients underwent uneventful SMILE in both eyes,whilst one patient underwent FS-LASIK for high astigmatism in both eyes and LRI in the right eye.CDVA of the eye with corneal opacity ranged from 20/22to 20/20 one to six weeks postoperatively.Two patients achieved better CDVA and no patients lost Snellen lines.The postoperative diopter was within±0.75 D for all eyes.Significant edema existed above the corneal opacity in one eye and dissipated soon.No eccentric corneal topography or morphological anomaly of the corneal cap or flap was observed.CONCLUSION:The cases demonstrate that SMILE or FS-LASIK is safe and effective to treat myopic astigmatism combined with deep corneal opacity lesions after comprehensive preoperative evaluation and appropriate candidate selection.FS-LASIK combined with LRI is also sufficient for correcting high astigmatism due to corneal scarring.

Corneal Blindness Caused by Accidental Ocular Use of Chlorhexidine (Hexz) Gel in Two Newborn Born in the Health District of Kati in Mali

Introduction: Corneal opacities in children are relatively common. In children, it is urgent because of the risk of irreversible amblyopia. The causes of these blindnesses vary considerably according to the regions of the world. Chlorhexidine digluconate is a broad-spectrum antiseptic directed against gram-positive and gram-negative bacteria. It has been used as an antiseptic for more than 50 years, both in humans and in animals. However, despite these benefits, it can cause serious damage if applied to the eyes. Incidents of eye damage with 7.1% chlorhexidine have been reported to WHO across Africa. Observation: We report and write two cases of bilateral corneal blindness caused by accidental ocular use of chlorhexidine (HEXZ) GEL 7.1% in two newborns in the health district of Kati in MALI. The ophthalmological examination had revealed corneal opacity, conjunctival hyperaemia and limbic ischemia greater than 50% in 1 eye out of 4, corresponding to stage IV of the ROPPER HALL classification;2 eyes out of 4 were at stage III and 1 eye out of 4 was at stage I of the same classification. Conclusion: It is essential to ensure correct use of chlorhexidine digluconate gel 7%. It is an antiseptic which should not be used on the ocular and auditory mucous membranes, at the risk of most often permanent burns.

OPAC系统用户搜索行为日志分析——以武汉大学图书馆为例

本文对武汉大学图书馆OPAC系统为期18天的搜索日志数据进行分析,以期揭示其用户搜索行为。研究采用Jansen提出的包含数据采集、处理和分析三阶段的分析框架,其中分析阶段又包含关键词、查询式和搜索会话三个层次。研究结果发现,用户输入的查询式都很短,接近2.9。高频查询词主要集中在数学、经济学、管理学、社会学等领域。搜索会话的平均持续时间是10分钟。搜索会话长度中文和非中文存在较大差异。

OPAC历史沿革及其发展趋势

对联机公共检索目录(OPAC)的发展历程、第三代基于网络环境的OPAC系统(Web-basedOPAC)的构成特点和IFLA的OPAC显示标准进行了简要分析,并在此基础上预测了OPAC今后的发展趋势。参考文献26。

图书馆书架定位系统的设计与实现

针对图书馆开架借阅服务模式下读者借书寻架不便的问题,设计实现一个基于Flash、ASP和数据库等技术的图书馆书架定位系统,通过生动直观的图形动画手段实现对图书的书架定位。以温州医学院图书馆为例,给出本系统与OPAC检索系统的集成方法,进一步提高系统的易用性。

阅读2.0:新一代的图书馆阅读推广

阅读2.0是Web2.0的理念与方法在社会阅读中的应用。近年来,电子阅读在纸质阅读逐年下降的趋势下,增长迅猛。图书馆要继续保持阅读大本营的地位,有效地进行图书的宣传推广,就需要积极运用阅读2.0,探索新的阅读推广方式,如与读者互动、与"豆瓣"双向互检的OPAC2.0的运用,海量信息的整合及一键搜索,众多web2.0工具的混搭,及区域图书馆共享优势的发挥等。

清华大学图书馆OPAC书封服务的设计与实现

清华大学图书馆应用Mashup模式,基于现有的OPAC设计并开发图书封面服务,使用户查询OPAC时在检索结果中能无缝集成显示书封,为读者提供更为直观的应用体验。主要介绍该图书封面数据源服务器的设计和实施方案,重点描述外部图书封面数据源的设计思路,如何利用Servlet技术建立该数据源的方法以及该服务器与图书馆管理系统的连接方式等内容。

OPAC2.0发展研究

以Web2.0的发展为背景,分析了Lib2.0的核心理念和OPAC2.0的特点,介绍了国外开发的具有OPAC2.0典型特征的3个OPAC系统,并结合WPopac系统给出一个OPAC2.0的设计构想,以期帮助研究与开发,最后指出OPAC2.0是OPAC系统的研究方向和发展目标。

我国高校图书馆资源整合的现状:调查与建议

对国内100余所高校图书馆的资源整合现状进行调研,总结资源整合方式及其实践情况,分析各种整合方式的优缺点,指出目前图书馆资源整合实践中存在的问题并提出相应的建议。

基于图书馆OPAC系统的OA期刊资源整合问题研究

随着社会与科技的不断进步,互联网上的OA资源日益增多,高质量的OA期刊不断涌现。OA资源引起了图书馆界的广泛关注。文章主要讨论了OA期刊与馆藏期刊编目整合的必要性及具体的技术方案。

试论Internet环境下OPAC系统的发展趋势

全面论述了OPAC系统的基本功能 ,回顾了OPAC系统的发展历程 ,阐述了OPAC系统将朝着基于Internet环境且支持Z3 9.5 0协议 。