WorldWideScience

Sample records for clear lens extraction

  1. Assessment of phacoaspiration techniques in clear lens extraction for correction of high myopia

    Directory of Open Access Journals (Sweden)

    Mostafa A El-Helw

    2010-03-01

    Full Text Available Mostafa A El-Helw, Ahmed M EmarahDepartment of Ophthalmology, Cairo University, EgyptPurpose: To evaluate various phacoaspiration techniques in clear lens extraction for the incidence of intraoperative difficulties and complications.Patients and methods: This was a prospective study in which bilateral clear lens extraction was performed on 40 eyes of 20 patients, to correct high myopia. The patients were divided into 2 groups: group A underwent supracapsular phacoaspiration; group B were the contralateral eyes of the same patient. These patients were operated on with endocapsular phacoaspiration with the divide and conquer (D and C technique. Preoperative ocular examination data were recorded and tested for significance. Intraoperative difficulties and complications such as nucleus cracking, capsule rupture and vitreous loss, and repeated chamber collapse were recorded. Postoperative examination data were recorded.Results: Mean age was 35.65 ± 5.85 years. Mean follow-up time was 17.1 ± 8.56 months. In group A mean myopia was -17.3 ± 5.07 diopters; in group B myopia was -17.9 ± 4.20 diopters. Mean preoperative uncorrected visual acuity (UCVA was 0.04 ± 0.0167, while the mean postoperative UCVA was 0.435 ± 0.1442. There was a significant difference in pre and postoperative BCVA within both groups, but not between the two groups. In both groups endothelial cell count (ECC showed a significant difference between pre- and postoperative data; however, there was no statistically significant difference between both groups in postoperative ECC. The effective phacoaspiration time for group A was 4.6 ± 1.6 seconds, and for group B 9.90 ± 2.27 seconds (P < 0.005. No cases of capsule rupture occurred in group A, but 3 cases occurred in group B (15 % (not significant, P = 0.231. Nucleus cracking did not occur in group A, but in group B 13 cases occurred (65%. Chamber collapse occurred in 4 cases (20% in group A and 5 cases (25% in group B (not

  2. Extração do cristalino translúcido: resultados visuais e freqüência de vítreo-retinopatias Clear lens extraction: visual outcomes and vitreoretinopathy frequence

    Directory of Open Access Journals (Sweden)

    João Arraes

    2006-10-01

    underwent clear lens extraction (CLE to correct myopia. METHODS: Thirty-five patients (60 eyes that underwent clear lens extraction at the "Fundação Altino Ventura" had median follow-up of 20.5 months. They were classified into 3 groups: Group I that was submitted to preoperative 360° preequatorial retinal photocoagulation; Group II that was submitted to prophylactic photocoagulation around predisposing lesions; and Group III that was not submitted to preoperative retinal photocoagulation. The presence of corrected visual acuity (CVA, refractional spherical equivalent (RSE and choroidal neovascularization (CNV, predisposing lesions and retinal detachment (RD was evaluated. RESULTS: Median corrected visual acuity value rose from 0.2 in the preoperative period to 0.5 in the postoperative period and refractional spherical equivalent decreased from -17SD to -1.7SD. There was no retinal detachment, but vitreous retinal traction areas appeared in 4 eyes (2 submitted to 360° laser and 2 not submitted to laser and 1 case of choroidal neovascularization also occurred. CONCLUSIONS: Clear lens extraction was an effective and predictable surgery to reduce myopias and an apparently safe procedure in patients with and without prophylactic preequatorial retinal photocoagulation. A longer follow-up in a larger group may validate its safety as a refractive surgery.

  3. A split-electrode for clearing scattered electrons in the RHIC e-lens

    Energy Technology Data Exchange (ETDEWEB)

    Gu X.; Pikin, A.; Thieberger, P.; Fischer, W.; Hock, J.; Hamdi, K.; Gassner,D.; Luo, Y.; Montag, C.; Okamura, M.

    2012-05-20

    We are designing two electron lenses that will be installed at RHIC IR10 to compensate for the head-on beam-beam effect. To clear accumulated scattered electrons from 100 GeV proton-electron head-on collisions in the e-lens, a clearing split electrode may be constructed. The feasibility of this proposed electrode was demonstrated via the CST Particle Studio and Opera program simulations. By splitting one of the drift tubes in the e-lens and applying {approx} 380 V across the two parts, the scattered electrons can be cleared out within several hundred micro-seconds. At the same time we can restrict the unwanted shift of the primary electron-beam that already passed the 2-m interaction region in e-lens, to less than 15um.

  4. Time lens assisted photonic sampling extraction

    Science.gov (United States)

    Petrillo, Keith Gordon

    Telecommunication bandwidth demands have dramatically increased in recent years due to Internet based services like cloud computing and storage, large file sharing, and video streaming. Additionally, sensing systems such as wideband radar, magnetic imaging resonance systems, and complex modulation formats to handle large data transfer in telecommunications require high speed, high resolution analog-to-digital converters (ADCs) to interpret the data. Accurately processing and acquiring the information at next generation data rates from these systems has become challenging for electronic systems. The largest contributors to the electronic bottleneck are bandwidth and timing jitter which limit speed and reduce accuracy. Optical systems have shown to have at least three orders of magnitude increase in bandwidth capabilities and state of the art mode locked lasers have reduced timing jitters into thousands of attoseconds. Such features have encouraged processing signals without the use of electronics or using photonics to assist electronics. All optical signal processing has allowed the processing of telecommunication line rates up to 1.28 Tb/s and high resolution analog-to-digital converters in the 10s of gigahertz. The major drawback to these optical systems is the high cost of the components. The application of all optical processing techniques such as a time lens and chirped processing can greatly reduce bandwidth and cost requirements of optical serial to parallel converters and push photonically assisted ADCs into the 100s of gigahertz. In this dissertation, the building blocks to a high speed photonically assisted ADC are demonstrated, each providing benefits to its own respective application. A serial to parallel converter using a continuously operating time lens as an optical Fourier processor is demonstrated to fully convert a 160-Gb/s optical time division multiplexed signal to 16 10-Gb/s channels with error free operation. Using chirped processing, an

  5. Antioxidant status of dog aqueous humor after extracapsular lens extraction

    Directory of Open Access Journals (Sweden)

    Barros P.S.M.

    2003-01-01

    Full Text Available We determined the antioxidant status of the aqueous humor after extracapsular lens extraction in 14 mongrel dogs weighing about 10 kg. The animals were examined by slit lamp biomicroscopy, applanation tonometry and indirect ophthalmoscopy. One eye was submitted to conventional extracapsular lens extraction and the other was used as control. Samples of aqueous humor were obtained by anterior chamber paracentesis before and at days 1, 2, 3, 7 and 15 after surgery. Total antioxidant status was determined as the capacity of aqueous humor to inhibit free radical generation by 2,2-azobis(2-amidopropane chlorine. Ascorbic acid concentration was measured by HPLC with UV detection. Protein content was determined with the biuret reagent. Statistical analysis was performed by ANOVA followed by the Tukey-Kramer test. Protein concentration increased from 0.61 to 22 mg/ml 24 h after surgery. These levels were maintained and returned to normal at day 7. Total antioxidant capacity was reduced from 50 to about 30 min until day 3 and at day 7 it was equal to control. Ascorbic acid levels were reduced from 252 to about 110 µM and then returned to control values at day 15. Considering the importance of ascorbic acid concentration in aqueous humor for the maintenance of the antioxidant status of the anterior segment of the eye, the decrease of antioxidant defenses suggests that the surgical procedures promote an oxidative stress condition in the eye.

  6. [The effect of crystalline lens extraction on intraocular pressure in patients with primary open-angle glaucoma].

    Science.gov (United States)

    Macarie, S; Macarie, Daniela

    2013-01-01

    This issue presents the results of a study on patients with cataract and primary open angle glaucoma who suffered lens extraction for cataract. We analise the effects of the lens extraction on the level of intraocular pressure at this patients.

  7. Anterior Crossbite and Crowding Correction with a Series of Clear Aligners Involving Lower Incisor Extraction: "The Clear Way" Case Report.

    Science.gov (United States)

    Bawaskar, Naval Suresh

    2015-01-01

    The Clear Aligner can be used to correct tooth movement without involving extraction, surgery, and other adjunct orthopaedic appliances. Some forms ofattachments are required with clear aligners to achieve all major types of orthodontic tooth movements. The Clear Aligner is a procedure that can be performed by a clinician with computer simulation/calculation. Since the Clear Aligner can be fabricated in steps, it is readily available to change the treatment sequence throughout the course of the treatment in cases of complex malocclusions. The patient can receive any necessary dental procedures with ease during the course of the treatment. The treatment can also be easily resumed even if the patient has not worn the aligners for a period of time. The purpose of this article is to report dental anterior crossbite correction with a series of Clear Aligners without the use of any forms of attachments. The Clear Aligner could be used as an alternative in appropriate cases for those who are reluctant with conventional appliances.

  8. Extracapsular cataract extraction : the fate of retained lens material and intraocular lenses

    NARCIS (Netherlands)

    J.P. Kappelhof (Johan)

    1987-01-01

    textabstractThe aim of this study was to examine the fate of the lens material that remains in the eye after an extracapsular cataract extraction both with and without insertion of an intraocular lens. Apart from this, the development of precipitates on the intraocular lenses was morphologically inv

  9. Eyeglasses lens contour extraction from facial images using an efficient shape description.

    Science.gov (United States)

    Borza, Diana; Darabant, Adrian Sergiu; Danescu, Radu

    2013-10-10

    This paper presents a system that automatically extracts the position of the eyeglasses and the accurate shape and size of the frame lenses in facial images. The novelty brought by this paper consists in three key contributions. The first one is an original model for representing the shape of the eyeglasses lens, using Fourier descriptors. The second one is a method for generating the search space starting from a finite, relatively small number of representative lens shapes based on Fourier morphing. Finally, we propose an accurate lens contour extraction algorithm using a multi-stage Monte Carlo sampling technique. Multiple experiments demonstrate the effectiveness of our approach.

  10. Eyeglasses Lens Contour Extraction from Facial Images Using an Efficient Shape Description

    Directory of Open Access Journals (Sweden)

    Diana Borza

    2013-10-01

    Full Text Available This paper presents a system that automatically extracts the position of the eyeglasses and the accurate shape and size of the frame lenses in facial images. The novelty brought by this paper consists in three key contributions. The first one is an original model for representing the shape of the eyeglasses lens, using Fourier descriptors. The second one is a method for generating the search space starting from a finite, relatively small number of representative lens shapes based on Fourier morphing. Finally, we propose an accurate lens contour extraction algorithm using a multi-stage Monte Carlo sampling technique. Multiple experiments demonstrate the effectiveness of our approach.

  11. A modified technique for extracting a dislocated lens with perfluorocarbon liquids and viscoelastics.

    Science.gov (United States)

    Dalma-Weiszhausz, José; Franco-Cardenas, Valentina; Dalma, Alejandro

    2010-01-01

    The authors describe a modified technique for extraction of a dislocated crystalline lens or large and hard lens fragments displaced into the vitreous cavity. An ophthalmic viscosurgical device was used around and on top of the heavy liquid bubble to keep the lens centered and less mobile for easier phacofragmentation or removal by the cutting-suction probe. This technique was used in 10 eyes, including cases of traumatic dislocation and Marfan syndrome, with excellent anatomical results and no complications that could be attributed to the surgical technique. The technique has also been used to retrieve and reposition dislocated intraocular lenses.

  12. Early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma: an economic evaluation based on data from the EAGLE trial

    Science.gov (United States)

    Javanbakht, Mehdi; Azuara-Blanco, Augusto; Burr, Jennifer M; Ramsay, Craig; Cooper, David; Cochran, Claire; Norrie, John; Scotland, Graham

    2017-01-01

    Objective To investigate the cost-effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma (PACG) compared to standard care. Design Cost-effectiveness analysis alongside a multicentre pragmatic two-arm randomised controlled trial. Patients were followed-up for 36 months, and data on health service usage and health state utility were collected and analysed within the trial time horizon. A Markov model was developed to extrapolate the results over a 5-year and 10-year time horizon. Setting 22 hospital eye services in the UK. Population Males and females aged 50 years or over with newly diagnosed PACG or primary angle closure (PAC). Interventions Lens extraction compared to standard care (ie, laser iridotomy followed by medical therapy and glaucoma surgery). Outcome measures Costs of primary and secondary healthcare usage (UK NHS perspective), quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER) for lens extraction versus standard care. Results The mean age of participants was 67.5 (8.42), 57.5% were women, 44.6% had both eyes eligible, 1.4% were of Asian ethnicity and 35.4% had PAC. The mean health service costs were higher in patients randomised to lens extraction: £2467 vs £1486. The mean adjusted QALYs were also higher with early lens extraction: 2.602 vs 2.533. The ICER for lens extraction versus standard care was £14 284 per QALY gained at three years. Modelling suggests that the ICER may drop to £7090 per QALY gained by 5 years and that lens extraction may be cost saving by 10 years. Our results are generally robust to changes in the key input parameters and assumptions. Conclusions We find that lens extraction has a 67–89% chance of being cost-effective at 3 years and that it may be cost saving by 10 years. Trial registration number ISRCTN44464607; Results. PMID:28087548

  13. Ethanol extract of Moringa oliefera prevents in vitro glucose induced cataract on isolated goat eye lens

    Directory of Open Access Journals (Sweden)

    Raghvendra Kurmi

    2014-01-01

    Full Text Available Aim of Study: The aim of current work was to evaluate in vitro anticataract potential of Moringa oliefera extract. Materials and Methods: Goat eye lenses were divided into 4 groups; Group served as control, Group II as toxic control, Group III and Group IV were incubated in extract (250 μg/ml and 500 μg/ml of extract of M. oliefera Group II, III and IV were incubated in 55 mM glucose in artificial aqueous humor to induce lens opacification. Estimation of total, water soluble protein, catalase, glutathione and malondialdehyde along with photographic evaluation of lens was done. Results: Group II (toxic control lenses showed high amount of MDA (Malondialdehyde, soluble, insoluble protein, decreased catalase and glutathione levels, while lenses treated with Moringa oliefera extract (Group III and Group IV showed significant (FNx01 P < 0.05 reduction in MDA and increased level of catalase, glutathione, total and soluble protein. Conclusion: Results of present findings suggest protective effect of Moringa oliefera in prevention of in vitro glucose induced cataract.

  14. The Effect of Liposome Encapsulated Daunorubicin on Rabbit Eyes after Extracapsular Lens Extraction

    Institute of Scientific and Technical Information of China (English)

    Mingxing Wu; Huaming Li; Shaozhen Li; Junwen Zeng

    2000-01-01

    Purpose: To investigate the effect of liposome encapsulated daunorubicin (DNR) on rabbit eyes when it was used in prevention of posterior capsule opacification (PCO).Methods: The liposome encapsulated DNR was prepared by modified freeze-thawing method. Each eye was injected with 0. 1 ml liposomes (0. 2 mg/ml and 20 μg/mlDNR) into the capsular bag during the extracapsular lens extraction (ECLE) in 10 rabbit eyes respectively. The phosphate buffer solution (PBS) was injected as control. Besides biomicroscope observation and histology examination of all eyes, the concentration of DNR in aqueous humor was also determined by high performance liquid chromatography (HPLC).Results: The morphology of liposome encapsulated DNR were similar to the blank liposome with round or ellipse shape. The encapsulated effecieney of liposome encapsulated DNR was 45.1%. The inflammatory response was much more severe both in 0. 2 mg/ml and 20 μg/ml DNR group than the control after liposome injection. All eyes in DNR group were showed severe corneal edema and opacity and lasted for 4 to 8weeks. Histopathological study revealed that lens epithelial proliferation occured by 4weeks and Soemmering' s ring developed by 8 weeks in control; However, in DNR group eye only a few LECs remained in the bag and there were obvious corneal edema and eosinophiles infiltration. Corneal endothelial cells were severely lost.Conclusion: The results suggest that liposome encapsulated DNR could inhibit metaplasia and proliferation of remnant lens epithelial cells after ECLE in rabbit eyes,but the severe toxicity must be avoided by further study.

  15. In vitro prevention of cataract by Oyster Mushroom Pleurotus florida extract on isolated goat eye lens

    Directory of Open Access Journals (Sweden)

    Aditya Ganeshpurkar

    2011-01-01

    Full Text Available Objectives : The aim of the present work was to evaluate the in vitro effect of Pleurotus florida extract cataract induced by glucose. Materials and Methods : Goat eye lenses were divided into four groups. Group I lenses were incubated in artificial aqueous humor with glucose concentration 5.5 mM (normal control. Group II lenses were incubated with glucose concentration 55 mM (toxic control. Group III and IV lenses incubated with glucose concentration 55 mM were incubated along with hydroethanolic extract of P. florida 250 μg/ml and 500 μg/ml and subjected to morphological and biochemical evaluation. Results : Group II lenses showed high amount of malondialdehyde (MDA soluble and insoluble protein and decreased catalase and glutathione levels, while lenses treated with P. florida extract showed significant (P < 0.05 reduction in MDA, increased level of catalase (P < 0.001, glutathione (P < 0.005 and total and soluble protein. Conclusions : Hydroethanolic extract of P. florida showed prevention of in vitro glucose induced cataract. Thus, the goat lens model could be used for testing of various anticataract agents.

  16. Effects of L-Carnitine and Cinnamon Extract Treatment on Lens Crystallins of Rats Fed High Fructose Diet

    Directory of Open Access Journals (Sweden)

    Mohamed H. Mahfouz

    2011-01-01

    Full Text Available Problem statement: Rats fed high dietary fructose are documented to form an acquired model of insulin resistance; the present study aims to investigate possible changes in lens crystallins of rats fed high fructose diet and the effects of administration of each exogenous L-Carnitine (CA and Cinnamon Extract (CE on protein glycation, oxidative stress and redox homeostasis in this rat model. Approach: A total number of 60 male Wister rats of body weight 120-160 g were divided into 4 groups of 15 rats each. Group 1 received control diet, while groups 2, 3 and 4: rats received high fructose diet (60g/100 g diet. After 2 weeks from fructose feeding, animals of group 3 were treated with L-carnitine (300 mg g-1 body weight/day i.p., while animals of group 4 were treated with cinnamon extract (0.5 mL/rat/day orally. At the end of experimental period (30 days, serum levels of glucose and insulin were determined. Lenses of each animal were dissected; molecular weights of crystalline, oxidative stress markers, early glycation of lens proteins and carbonyl group were assayed. Results: A significant decline in antioxidants and increase in lipid peroxidation products, protein oxidation and protein glycation were observed in lens samples obtained from fructose-fed rats. Administration of each CA and CE to fructose-fed rats significantly attenuated oxidative damage and protein glycation and returned levels of antioxidants to near those in control group. Chromatographic analysis of lens crystalline of rats fed high fructose diet showed diffused peaks, indicating crystalline aggregation. Conclusion: The results of the present study indicate that dietary fructose disturbs lens integrity and administration of L-carnitine or cinnamon extract may safeguard the lens by minimizing the protein aggregation, preventing glycation and oxidative stress in animals fed high fructose diet. L-carnitine has more potent effects than CE in this animal model.

  17. Enhanced light extraction efficiency of chip-on board light-emitting diodes through micro-lens array fabricated by ion wind

    Science.gov (United States)

    Chu, Jingcao; Lei, Xiang; Wu, Jiading; Peng, Yang; Liu, Sheng; Yang, Qian; Zheng, Huai

    2017-03-01

    Low light extraction efficiency (LEE) is a key challenge of chip-on board (COB) packaging light-emitting diodes (LEDs). In this paper, a facile preparation of micro-lens array was proposed based on the ion wind patterning. The geometries and sizes of the micro-lens arrays were controlled through adjusting the voltage parameter of the ion wind generation. Consequently, the micro-lens array with the diameter of 180 μm and the gap distance of 15 μm has been fabricated. Benefitting from this micro-lens array, the LEE of COB packaging LEDs was enhanced by 9%. This facile fabrication of micro-lens array would be a promising method to improve the LEE of COB packaging LEDs.

  18. Laser induced-thermal lens spectrometry after cloud point extraction for the determination of trace amounts of palladium

    Science.gov (United States)

    Shokoufi, N.; Shemirani, F.; Shokoufi, M.

    2009-10-01

    Cloud point extraction (CPE) in combination with thermal lens spectrometry (TLS) has been developed for the preconcentration and determination of palladium. TLS and CPE methods have good matching conditions for the combination because TLS is a suitable method for the analysis of low volume samples obtained after CPE. Palladium was complexed with 1-(2-pyridylazo)-2-naphthol (PAN) as a complexing agent in an aqueous medium and concentrated by octylphenoxypolyethoxyethanol (Triton X-114) as a surfactant. After the phase separation at 60 °C based on the cloud point extraction of the mixture, the surfactant-rich phase was dried and the remaining phase was dissolved using 20 μL of carbon tetrachloride. The obtained solution was introduced into a quartz microcell and the analyte was determined by laser induced-thermal lens spectrometry (LI-TLS). The single-laser TLS was used as a sensitive method for the determination of palladium-PAN complex in 20 μL of the sample. Under optimum conditions, the analytical curve was linear for the concentration range of 0.3-60 ng mL -1 and the detection limit was 0.04 ng mL -1. The enhancement factor of 460 was achieved for 10 mL samples containing the analyte and relative standard deviations were lower than 5%. The developed method was successfully applied to the extraction and determination of palladium in water samples.

  19. Preventative effects of Ginkgo biloba extract (EGb761) on high glucose-cultured opacity of rat lens.

    Science.gov (United States)

    Lu, Qian; Yang, Tingting; Zhang, Mingzhu; Du, Lei; Liu, Ling; Zhang, Nan; Guo, Hao; Zhang, Fan; Hu, Gang; Yin, Xiaoxing

    2014-05-01

    Diabetic cataract is one of the earliest secondary complications of diabetes, and it is characterized by opacification of the eye lens. In this study, we examined the protective effects of Ginkgo biloba extract (EGb761) on rat lenses cultured in high-glucose conditions. The cultured rat lenses were divided into six groups: normal group, high-glucose group, high glucose plus low, medium, and high concentrations of EGb761 groups, and a high glucose plus bendazac lysine group. The activities of antioxidases, aldose reductase, advanced glycosylation end products, transforming growth factor-β2, Smad2/3, E-cadherin, and α-smooth muscle actin were assessed by different methods. Compared with the levels in the high glucose group, EGb761 decreased the intensity of oxidative stress, decreased aldose reductase activation and the level of advanced glycosylation end products, and suppress the transforming growth factor-β2 or Smad pathway activation, further increase the expression of E-cadherin and decrease α-smooth muscle actin, and therefore, prevents the pathological changes of high glucose-induced lens epithelial cells and ameliorated lens opacity. These results suggest that EGb761 has protective effects on several pharmacological targets in the progress of diabetic cataract and is a potential drug for the prevention of diabetic cataract.

  20. [Lens platform].

    Science.gov (United States)

    Łukaszewska-Smyk, Agnieszka; Kałuzny, Józef

    2010-01-01

    The lens platform defines lens structure and lens material. Evolution of lens comprises change in their shape, angulation of haptens and transition of three-piece lens into one-piece lens. The lens fall into two categories: rigid (PMMA) and soft (siliconic, acrylic, colameric). The main lens maaterials are polymers (hydrophilic and hydrophobic). The lens platform has an effect on biocompatibility, bioadhesion, stability of lens in capsule, degree of PCO evolution and sensitiveness to laser damages.

  1. Extracting Leaf Area Index by Sunlit Foliage Component from Downward-Looking Digital Photography under Clear-Sky Conditions

    Directory of Open Access Journals (Sweden)

    Yelu Zeng

    2015-10-01

    Full Text Available The development of near-surface remote sensing requires the accurate extraction of leaf area index (LAI from networked digital cameras under all illumination conditions. The widely used directional gap fraction model is more suitable for overcast conditions due to the difficulty to discriminate the shaded foliage from the shadowed parts of images acquired on sunny days. In this study, a new LAI extraction method by the sunlit foliage component from downward-looking digital photography under clear-sky conditions is proposed. In this method, the sunlit foliage component was extracted by an automated image classification algorithm named LAB2, the clumping index was estimated by a path length distribution-based method, the LAD and G function were quantified by leveled digital images and, eventually, the LAI was obtained by introducing a geometric-optical (GO model which can quantify the sunlit foliage proportion. The proposed method was evaluated at the YJP site, Canada, by the 3D realistic structural scene constructed based on the field measurements. Results suggest that the LAB2 algorithm makes it possible for the automated image processing and the accurate sunlit foliage extraction with the minimum overall accuracy of 91.4%. The widely-used finite-length method tends to underestimate the clumping index, while the path length distribution-based method can reduce the relative error (RE from 7.8% to 6.6%. Using the directional gap fraction model under sunny conditions can lead to an underestimation of LAI by (1.61; 55.9%, which was significantly outside the accuracy requirement (0.5; 20% by the Global Climate Observation System (GCOS. The proposed LAI extraction method has an RMSE of 0.35 and an RE of 11.4% under sunny conditions, which can meet the accuracy requirement of the GCOS. This method relaxes the required diffuse illumination conditions for the digital photography, and can be applied to extract LAI from downward-looking webcam images

  2. 晶状体半脱位摘出手术中的后部辅助抬升技术%Posterior assisted levitation for subluxated lens extraction

    Institute of Scientific and Technical Information of China (English)

    贡亦清; 吴燕

    2011-01-01

    目的 评价后部辅助抬升技术在晶状体半脱位摘出手术中应用的效果.方法 回顾性分析7例(7眼)晶状体半脱位(脱离范围超过2个象限)资料,手术方法采用平坦部穿刺辅助器械的后部辅助抬升技术,将半脱位晶状体顶入前房后摘出.对术前、术后视力、眼压及视网膜并发症等情况进行分析.结果 7例均顺利摘出半脱位晶状体,未行后段玻璃体切除术.术后并发症较少.结论 后部辅助抬升技术应用于脱离范围超过2个象限的晶状体半脱位摘出手术是简单、有效安全的方法.%Objective To evaluate the clinical effect of subluxated lens extraction with posterior assisted levitation. Methods The data in 7 cases (7 eyes) of subluxation of lens (over two quadrant) were analysed retrospectively. An assistant instrument had taped into vitreous cavity through pars plana for levation of the subhtxated lens. The lens was elevated into anterior chamber and was extracted. Preoperative and postoperative visual acuity, intraocular pressure and retinal complications were observed. Results Subluxated lens of all the 7 cases were extracted smoothly without posterior vitrectomy. Conclusions Posterior levitation assisted lens is effective and safe for subluxated lens of over two quadrant.

  3. Clear & Simple

    Science.gov (United States)

    ... Cultural Respect Language Access Talking to Your Doctor Research Underway Plain Language Clear & Simple What is Clear & Simple? Clear & Simple ... schedule? A: Pretesting need not be an elaborate, time-consuming research project and depends on: How quickly you work, ...

  4. Monovision法超声乳化透明晶状体吸除术治疗高度近视的临床观察%Clear lens phacoemulsification with monovision for the correction of high myopia

    Institute of Scientific and Technical Information of China (English)

    武哲明; 张静琳; 陈韵; 林振德

    2012-01-01

    目的 探讨Monovision法超声乳化透明晶状体吸除术联合人工晶状体植入治疗高度近视的临床疗效.方法 对45例(90眼)高度近视患者行双眼透明晶状体超声乳化吸除联合人工晶状体植入术,术前行常规眼科检查和眼底检查、视觉需要调查、主视眼检测、生物测量,术中植入单焦点折叠式IOL.根据患者视觉需要分为两组:Monovision组28例,男11例,女17例,根据生物测量结果,术中植入的人工晶状体度数使患者主视眼术后目标屈光度-0.5~0.0D,非主视眼术后目标屈光度-2.0~-2.5D;对照组17例,男5例,女12例,双眼术后目标屈光度-0.5~0.0D.对术后双眼裸跟远近视力、屈光度等随访观察3个月,结合术后问卷评估结果进行统计学分析.结果 两组术后屈光度与术前预留屈光度无统计学差异(P>0.05).术后3个月,Monovision组和对照组双眼同时视裸眼远视力分别为(0.83±0.15)、(0.81±0.13),差异无统计学意义(P> 0.05).Monovision组双眼同时视近视力(0.68±0.25)好于对照组(0.38±0.21),差异有统计学意义(P< 0.03).术后3个月远距离用眼,两组不带眼镜分别是97.5%、98.3%,差异无统计学意义(P>0.05 ).术后3个月近距离用眼从不带眼镜的比例,两组分别为78.5%,20.3%,差异有统计学意义(P<0.05).术后3个月,两组均无视网膜脱离、黄斑囊样水肿发生.结论 Monovision法超声乳化透明晶状体吸除术治疗高度近视是安全有效的方法,具有术后视力好、并发症少、预测屈光状态准确、远近用眼均不用戴镜等优点.%Objective To explore the clinical efficacy of clear lens phacoemulsification with monovision combined with artificial lens implantation for the correction of high myopia.Methods This study included 45 patients ( 90 eyes ) diagnosed as high myopia.The distant and near visual acuity ( VA ) and the dominant eye were examined.All the eyes received binocular

  5. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A.; Foreman, L.R.

    1997-07-08

    This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

  6. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

    1997-01-01

    This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

  7. Distributions and Losses of Logging Residues at Clear-Felled Areas during Extraction for Bioenergy: Comparing Dried- and Fresh-Stacked Method

    Directory of Open Access Journals (Sweden)

    Bengt Nilsson

    2015-11-01

    Full Text Available It is well known that a large proportion of available logging residues intended for extraction will not reach the energy-conversion industry, because some are lost during transportation or left on the clear-felled area. However, there is little understanding of where logging residue losses occur in the supply chain. In this study, the distribution of logging residues for two methods (dried- and fresh-stacked method to extract logging residues were studied in one clear-felled area. In addition, residue fractions were examined in a detailed comparison. Even though the fresh-stacked method left somewhat more logging residues at the clear-felled area, the differences are small between the methods. Approximately 30% of the total amount of logging residues was left behind between the harvester heaps, with an additional 10%–15% under these heaps and approximately 2%–3% beneath the windrows. The final product that was delivered to the energy-conversion industry was very similar, regardless of the extraction method used. The delivered chipped logging residues had moisture contents of 37% and 36% following fresh- and dried-stacked methods respectively, and in both cases the needle content in the processed logging residues was approximately 10%. However, the total amount of fine fractions (needles and fines was slightly higher following dried-stacking.

  8. Clear retainer

    Directory of Open Access Journals (Sweden)

    Priyakorn Chaimongkol

    2017-01-01

    Full Text Available A clear retainer is a removable retainer that is popular in the present day. Compared with conventional fixed and removable orthodontic retainers, it is a more esthetic, comfortable, and inexpensive appliance. Although several studies have been published about clear retainers, it could be difficult to interpret the results because of the variety of study designs, sample sizes, and research methods. This article is intended to compile the content from previous studies and discuss advantages, disadvantages, fabrication, insertion, and adjustment. Moreover, the effectiveness in maintaining dental position, occlusion, retention protocols, thickness, and survival rate of clear retainers is discussed.

  9. SNOW CLEARING

    CERN Multimedia

    Groupe de Transport/Transport Group

    1999-01-01

    In order to facilitate snow-clearing operations, which commence at 4.30 every morning, drivers of CERN vehicles are kindly requested to group their cars together in the car parks. This will greatly help us in our work. Thank you for your co-operation.Transport Group / ST-HMTel. 72202

  10. Combined ab interno trabeculotomy and lens extraction: a novel management option for combined uveitic and chronic narrow angle raised intraocular pressure.

    Science.gov (United States)

    Lin, Siying; Gupta, Bhaskar; Rossiter, Jonathan

    2016-02-01

    Minimally invasive glaucoma surgery is a developing area that has the potential to replace traditional glaucoma surgery, with its known risk profile, but at present there are no randomised controlled data to validate its use. We report on a case where sequential bilateral combined ab interno trabeculotomy and lens extraction surgery was performed on a 45-year-old woman with combined uveitic and chronic narrow angle raised intraocular pressure. Maximal medical management alone could not control the intraocular pressure. At 12-month follow-up, the patient had achieved stable intraocular pressure in both eyes on a combination of topical ocular antiglaucomatous and steroid therapies. This case demonstrates the effectiveness of trabecular meshwork ablation via ab interno trabeculotomy in a case of complex mixed mechanism glaucoma.

  11. Fuchs Heterochromic Iridocylitis: Clinical Characteristics and Outcome of Cataract Extraction with Intra Ocular Lens Implantation in a Kashmiri Population- A Hospital Based Study

    Science.gov (United States)

    Lone, Imtiyaz; Mir, Adil Majid; Rashid, Aamir; Latif, Mehreen

    2016-01-01

    Introduction Fuchs Heterochromic Iridocylitis (FHI) is a rare form of uveitis which is frequently complicated by cataract and glaucoma, but it does not show typical features of uveitis like pain, redness and posterior synechia. Aim To study the clinical characteristics and outcome of cataract extraction with Intra Ocular Lens (IOL) implantation in patients with FHI. Materials and Methods The present prospective study was carried out in the Postgraduate Department of Ophthalmology, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Bemina from March 2012 to January 2015. The study included 33 eyes of 32 patients of FHI who underwent thorough clinical examination and cataract surgery with IOL implantation and were evaluated based on their visual outcome and intra and post-operative complications. Post-operative follow-up was done on 1st day, one week, one month, two month, six month and at twelve months. Results Mean age of our study group was 33.9 years (Range 18 to 65 years). No male or female preponderance was seen. There was bilateral involvement of eyes in only one case. Cataract and stellate keratic precipitates were present in all cases whereas, heterochromia was present in only six eyes (18.75%). Best Corrected Visual Acuity (BCVA) showed a significant improvement following cataract surgery (p 6/12). Most common causes of decreased vision post-operatively were vitreous opacities in nine eyes (27.27%) followed by glaucoma in eight eyes (24.24%) and posterior capsular opacification in six eyes (18.18%). Conclusion Cataract extraction with IOL lens implantation in FHI is a safe procedure associated with good visual prognosis and few complications. However, glaucoma is one of the main concerns and should be closely monitored both pre and post-operatively. PMID:28208900

  12. SURGICAL OUTCOME OF TRIPLE PROCEDURE AS PENETRATING KERATOPLASTY WITH EXTRACAPSULAR CATARACT EXTRACTION WITH POSTERIOR CHAMBER INTRAOCULAR LENS IMPLANTATION IN PATIENTS WITH BOTH CENTRAL CORNEAL OPACITY AND ADVANCED CATARACT AT RURAL SET UP

    Directory of Open Access Journals (Sweden)

    Shubhangi Nigwekar, Kishor Badhe, Neeta Misra, Surekha Bangal

    2015-10-01

    Full Text Available Purpose: To study the surgical outcome of triple procedure as penetrating keratoplasty (PKP with conventional extra capsular cataract extraction (ECCE with posterior chamber intraocular lens (PCIOL implantation in patients with both central corneal opacity and advanced cataract at rural set up. Introduction: When corneal opacity and cataract present together then well-established and effective triple procedure is indicated. Prognosis for a clear graft is good in triple, as graft endothelium does not touch the hard nucleus which may occur in two steps or sequential surgery. It provides faster visual rehabilitation. Being single step procedure it reduces patient’s hospital stay, postoperative care and follows up visits. Methodology: In this hospital based observational , three years longitudinal study, we studied the surgical outcome of relatively rare one step triple procedure as PKP with conventional ECCE with PCIOL implantation in sulcus or in bag, in patients with both central corneal opacity and advanced cataract at rural set up. The outcome measures included graft clarity on slit lamp, postoperative unaided visual acuity with Snellen’s chart and the occurrence of postoperative complications after taking IEC permission and informed written consent in local language from study patients. Results: Out of 13 study patients mean age was 61.15yrs (Range50-80yrs. Follow up range was 9-34 months. At final follow up 9 patients (69.23% had clear grafts and 61.52% patients gained visual acuity >6/24. Graft failure was the most common post operative complication in 30.76% followed by Posterior capsular opacification (PCO in 15.38% patients which was treated well with YAG laser capsulotomy. Conclusion: Triple procedure gives good results in respect to graft clarity, unaided vision, and faster rehabilitation.

  13. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil......Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory...... of probabilistic functionalism, and concerns the environment and the mind, and adaptation by the latter to the former. This entry is about the lens model, and probabilistic functionalism more broadly. Focus will mostly be on firms and their employees, but, to fully appreciate the scope, we have to keep in mind...

  14. Study of preparations of bee pollen extracts, antioxidant and antibacterial activity Estudo das preparações de extratos de pólen apícola, atividade antioxidante e antibacteriana

    Directory of Open Access Journals (Sweden)

    Solange Teresinha Carpes

    2007-12-01

    Full Text Available The aim of this study was to determine the antioxidant activity, phenolic content and antibacterial activity of pollen extracts obtained with different concentrations of ethanol. Each extraction condition (ethanol solutions from 40 to 90% had a different effect in the phenolic compounds content. Although, the pollen extract obtained at 60, 70 and 80% of ethanol showed relatively higher levels of phenolic compounds (>10 mg/g and did not present statistical significant difference between the extraction conditions. The amount of total phenolics ranged from 3.6 to 8.1 and 6.6 to 10.9 mg GAE/g for Alagoas state and Parana state pollen, respectively. The higher value for antioxidant activity index was 83.30% for the pollen from Alagoas state and 81.15 % for Parana state pollen. The highest degree of antioxidant activity was found in the extraction at 60% of ethanol solution for Parana state pollen, which also showed the highest concentration of polyphenol compounds. Staphylococcus aureus was inhibited by the ethanolic extract of Alagoas state pollen in all the concentrations of solvent, except the ethanolic extract of pollen at 90%. The extract at 60% of ethanol solution (Parana sample inhibited Bacillus subtilis, Pseudomonas aeruginosa and Klebsiella sp.Objetivou-se, neste estudo determinar compostos fenólicos, a atividade antioxidante a antibacteriana dos extratos etanólicos de pólen, obtidos com diferentes concentrações de etanol. As diferentes condições de extração (etanol de 40 a 90% apresentaram diferentes efeitos no conteúdo dos compostos fenólicos extraídos. Os extratos de pólen obtidos com etanol a 60, 70 e 80% apresentaram maiores níveis de compostos fenólicos (>10 mg/g e não apresentaram diferenças estatísticas entre essas condições de extração. A quantidade de compostos fenólicos nos extratos de pólen variou de 3.6 a 8.1 e 6.6 a 11 mg de equivalente em ácido gálico por g de pólen (GAE, para os estados de Alagoas

  15. Observation of the Effect of Small Incision Extracapsular Cataract Extraction and Intraocular Lens Implantation%探析小切口无缝线白内障囊外摘除加人工晶体植入效果观察

    Institute of Scientific and Technical Information of China (English)

    韩艳秋

    2015-01-01

    目的:探讨小切口无缝线白内障囊外摘除加人工晶体植入的效果。方法白内障患者65例,对照组患者使用大切口白内障囊外摘除加人工晶体植入术进行治疗,观察组患者使用小切口无缝线白内障囊外摘除加人工晶体植入术进行治疗。结果经过治疗后,观察组患者的效果明显优于对照组患者,P<0.05。结论小切口无缝线白内障囊外摘除加人工晶体植入在治疗白内障中具有良好的效果。%ObjectiveTo investigate the small incision without suture cataract extracapsular extraction and intraocular lens implantation. Methods65 cases of cataract patients, patients in the control group using a large incision extracapsular cataract extraction and intraocular lens implantation for treatment, patients in the observation group using small incision extracapsular cataract extraction and intraocular lens implantation for treatment.Results after treatment, the effect of observation group of patients is better than the control group,P<0.05.Conclusion Small incision without suture cataract extracapsular extraction and intraocular lens implantation in the treatment of cataract has good effect.

  16. Phakic Pattern Pseudoexfoliation Material Accumulation on Intraocular Lens Surface

    Directory of Open Access Journals (Sweden)

    Emre Güler

    2014-03-01

    Full Text Available Pseudophakic pseudoexfoliation is the accumulation of pseudoexfoliation material on the intraocular lens. Most of the cases have showed scattered flecks of pseudoexfoliation material on the surface of the intraocular lens. However, the phakic pattern consisting of classic three-zone on the intraocular lens is rarely observed. In this case report, we describe a phakic pattern pseudoexfoliation material on the intraocular lens surface 8 years after cataract extraction. (Turk J Ophthalmol 2014; 44: 156-7

  17. Phakic Pattern Pseudoexfoliation Material Accumulation on Intraocular Lens Surface

    OpenAIRE

    Emre Güler; Aylin Tenlik; Tuba Kara Akyüz

    2014-01-01

    Pseudophakic pseudoexfoliation is the accumulation of pseudoexfoliation material on the intraocular lens. Most of the cases have showed scattered flecks of pseudoexfoliation material on the surface of the intraocular lens. However, the phakic pattern consisting of classic three-zone on the intraocular lens is rarely observed. In this case report, we describe a phakic pattern pseudoexfoliation material on the intraocular lens surface 8 years after cataract extraction. (Turk J Ophthalm...

  18. 小切口白内障摘除联合人工晶体植入术52例临床分析%Clinical analysis of 52 cases of small incision cataract extraction combined with intraocular lens implantation

    Institute of Scientific and Technical Information of China (English)

    阿西木

    2014-01-01

    目的:对小切口白内障摘除联合人工晶体植入术的临床疗效进行分析。方法选取我院52例白内障患者为例,所有患者均实施小切口白内障摘除联合人工晶体植入术进行治疗,观察和分析患者的手术治疗效果。结果患者术后显示视力水平有所改善,并发症患者经过处理均全部治愈。结论采用小切口白内障摘除联合人工晶体植入术对白内障患者进行治疗,创伤性小,治疗效果显著,安全性高,值得推广和普及。%Objective The clinical efficacy of small incision cataract extraction and intraocular lens implantation for analysis. Methods 52 cases of cataract patients in our hospital, for example, all patients were implementing small incision cataract extraction and intraocular lens implantation for treatment, observation and analysis of surgical treatment of patients. Results Postoperative patients showed improvement in visual acuity and complications in patients treated were cured. Conclusion the use of small incision cataract extraction and intraocular lens implantation for cataract treatment, traumatic small, significant treatment effect, safe, worthy of promotion and popularization.

  19. Clear evidence of carcinogenic activity by a whole-leaf extract of Aloe barbadensis miller (aloe vera) in F344/N rats.

    Science.gov (United States)

    Boudreau, Mary D; Mellick, Paul W; Olson, Greg R; Felton, Robert P; Thorn, Brett T; Beland, Frederick A

    2013-01-01

    Aloe barbadensis Miller (Aloe vera) is an herbal remedy promoted to treat a variety of illnesses; however, only limited data are available on the safety of this dietary supplement. Drinking water exposure of F344/N rats and B6C3F1 mice to an Aloe vera whole-leaf extract (1, 2, and 3%) for 13 weeks resulted in goblet cell hyperplasia of the large intestine in both species. Based upon this observation, 2-year drinking water studies were conducted to assess the carcinogenic potential of an Aloe vera whole-leaf extract when administered to F344/N rats (48 per sex per group) at 0.5, 1, and 1.5%, and B6C3F1 mice (48 per sex per group) at 1, 2, and 3%. Compared with controls, survival was decreased in the 1.5% dose group of female rats. Treatment-related neoplasms and nonneoplastic lesions in both species were confined primarily to the large intestine. Incidences of adenomas and/or carcinomas of the ileo-cecal and cecal-colic junction, cecum, and ascending and transverse colon were significantly higher than controls in male and female rats in the 1 and 1.5% dose groups. There were no neoplasms of the large intestine in mice or in the 0 or 0.5% dose groups of rats. Increased incidences of mucosa hyperplasia of the large intestine were observed in F344/N rats, and increased incidences of goblet cell hyperplasia of the large intestine occurred in B6C3F1 mice. These results indicate that Aloe vera whole-leaf extract is an intestinal irritant in F344/N rats and B6C3F1 mice and a carcinogen of the large intestine in F344/N rats.

  20. Algorithm design of liquid lens inspection system

    Science.gov (United States)

    Hsieh, Lu-Lin; Wang, Chun-Chieh

    2008-08-01

    In mobile lens domain, the glass lens is often to be applied in high-resolution requirement situation; but the glass zoom lens needs to be collocated with movable machinery and voice-coil motor, which usually arises some space limits in minimum design. In high level molding component technology development, the appearance of liquid lens has become the focus of mobile phone and digital camera companies. The liquid lens sets with solid optical lens and driving circuit has replaced the original components. As a result, the volume requirement is decreased to merely 50% of the original design. Besides, with the high focus adjusting speed, low energy requirement, high durability, and low-cost manufacturing process, the liquid lens shows advantages in the competitive market. In the past, authors only need to inspect the scrape defect made by external force for the glass lens. As to the liquid lens, authors need to inspect the state of four different structural layers due to the different design and structure. In this paper, authors apply machine vision and digital image processing technology to administer inspections in the particular layer according to the needs of users. According to our experiment results, the algorithm proposed can automatically delete non-focus background, extract the region of interest, find out and analyze the defects efficiently in the particular layer. In the future, authors will combine the algorithm of the system with automatic-focus technology to implement the inside inspection based on the product inspective demands.

  1. 先天性白内障术后视功能观察%Observation of visual function after congenital cataract extraction and intraocular lens implantation

    Institute of Scientific and Technical Information of China (English)

    张新爱; 刘桂香; 万鲁芹; 徐琳琳; 许之娟

    2011-01-01

    Objective To investigate the factors of visual function change after congenital cataract extraction and intraocular lens (IOL) implantation through the observation of visual acuity and stereosis. Methods A total of 33 cases were divided into 2 groups according to operation age, 3 months-2 years old was named group A, 2-6 years old was named group B. To analyze the best corrected distant visual acuity and the near and distance stereo-acuity after cataract extraction with IOL implantation. They were followed up for an average of 3 years. Results After operation, 100% and 90% patients were relieved from blindness in group A and group B respectively, and two groups did not show difference (P >0.05); 94% and 70% patients obtained corrected vision ≥ 0.3 in group A and group B, and two groups showed significant difference (P <0.05); 70.6% and 41.7%patients gained the near stereo acuity in group A and group B respectively, the recovery rate of the near stereo-acuity did not show difference (P >0.05); 58.8% and 16.7% patients acquired the distance stereo acuity in group A and group B respectively, the recovery rate of the distance stereo-acuity showed significant difference between two groups (P <0.05). Conclusions The recovery of visual function of child's congenital cataract is related to the operation age. And the children can get better visual function if they accepte surgery earlier.%目的 观察先天性白内障术后视力及立体视恢复情况.探讨视功能变化的影响因素.方法 将33例(56只眼)先天性白内障患儿据手术时年龄3月至2岁,>2~6岁分为A、B两组,A组21例36只眼,B组12例20只眼,对术后平均随访3年的最佳矫正远视力及远近立体视恢复情况进行分析.结果 术后脱盲率,A组为100%,B组为90%,两组之间的差别无统计学意义(P>0.05);脱残率,A组为94%,B组为70%,两组之间差别具有统计学意义(P<0.05);远立体视的获得率A组为58.8%,B组为16.7%,两组

  2. Contact lens in keratoconus

    Directory of Open Access Journals (Sweden)

    Varsha M Rathi

    2013-01-01

    Full Text Available Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP lenses, soft and soft toric lenses, piggy back contact lenses (PBCL, hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the English language with the keywords keratoconus and various contact lenses such as Rose k lens, RGP lens, hybrid lens, scleral lens and PBCL.

  3. Restoring lens capsule integrity enhances lens regeneration in New Zealand albino rabbits and cats.

    Science.gov (United States)

    Gwon, A; Gruber, L J; Mantras, C

    1993-11-01

    In studies conducted by numerous investigators for 150 years, lenses regenerated following endocapsular lens extraction in New Zealand albino rabbits have been irregular in shape, appearing primarily doughnut-shaped as a result of lack of lens growth at the site of the anterior capsulotomy and its adhesion to the posterior capsule. In the present study, we restored the lens capsule integrity by inserting a collagen patch at the time of surgery to seal the anterior capsulotomy and to improve the shape and structure of the regenerated lenses. We then filled the capsule bag with air to prevent adhesions between the anterior and posterior capsule and maintain capsule tautness and shape. Lens regeneration was first noted as early as one to two weeks. Regenerated lens filled approximately 50% of the capsule bag at two weeks and 100% by five weeks. Subsequent growth was in the anterior-posterior direction and measured by A-scan biometry. Lens thickness increased by 0.3 mm per month. The regenerated lenses were spherical with normal cortical structure and a nuclear opacity. In conclusion, restoration of lens capsular integrity with a collagen patch following endocapsular lens extraction enhanced the shape, structure, and growth rate of the regenerated lenses. In addition, lens regeneration was shown to occur in two cats.

  4. Clinical analysis of HIV positive patients cataract extraction and intraocular lens implantation%人类免疫缺陷病毒阳性者白内障手术临床观察

    Institute of Scientific and Technical Information of China (English)

    马建黎; 臧新莲; 闫珺

    2013-01-01

    目的 探讨人类免疫缺陷病毒(HIV)阳性患者白内障手术的疗效与安全性.方法 HIV阳性者16例(16眼)行白内障摘出人工晶状体植入术的疗效及安全性,进行回顾分析.结果 术后视力<0.1者2眼.0.1 ~0.5者9眼,>0.5者5眼.结论 HIV阳性患者行白内障摘出人工晶状体植入术安全、有效.%Objective To observe the results and safety of catarat surger in HIV positive patients.Methods In the surgery of cataract treatment from october.2007 to December.2011,the treating results and safety of 16 cases (16 eyes) of HIV positive patients cataract extraction and intraocular lens implantation were retrospectively studied.Results 2 cases (2 eyes) of whose vision were less than 0.1 after surgery.9 cases (9 eyes) of whose visual acuity were between 0.1 and 0.5.5 cases (5 eyes) of whose visual acuity were higher than 0.5.Conclusion HIV positive patients cataract extraction and intraocular lens implantation are safe and effective.

  5. 热水萃取法生产澄清香蕉汁的研究%Study on Processing of Clear Banana Juice Using Hot Water Extraction Method

    Institute of Scientific and Technical Information of China (English)

    郑欣; 余元善; 吴继军; 徐玉娟; 肖更生; 黄婉华; 温靖

    2014-01-01

    In this study, the effects of hot water temperature on clarity, total soluble solids, polyphenol oxidase (PPO) and color of banana juice during hot water ex-traction were discussed based on the theory in which heat treatment might induce the pectin and protein in banana pulp to form insoluble products. The results showed the hot water temperature had a significant effect on the formation of insol-uble polymers in banana pulp from pectin and protein. In 75 ℃ water, the pectin and protein in banana pulp were most inclined to form insoluble products. Under this condition, the clarity of banana juice was also highest. The light transmittance at 660 nm was close to 90%. In the banana juice, extracted by 75 ℃ water, the pectin and protein contents were lowest, and they were lower than 7.3 mg/100 ml and 12.9 mg/100 ml respectively. The 75 ℃ water could not inactivate completely the pectin in banana pulp due to its high heat resistance, Therefore, 0.05% L-cys-teine or ascorbic acid needed to be added into banana pulp to inhibit the browning of juice induced by residual PPO.%基于热处理可能诱导香蕉果肉中果胶和蛋白质形成水不溶物的理论,研究了热水萃取温度对香蕉汁澄清度、可溶性固形物含量、多酚氧化酶(PPO)和色泽的影响。结果发现,热水温度对香蕉果肉中果胶和蛋白质形成水不溶性聚合物的能力有显著的影响,其中75℃的热水萃取诱导香蕉果肉中果胶和蛋白质形成水不溶物的能力最强,获得香蕉汁的澄清度最高,其透光率(660 nm)接近90%;75℃热水萃取获得的香蕉汁的果胶和蛋白含量最低,分别低于每100 ml 香蕉汁7.3和12.9 mg。由于香蕉果肉中 PPO耐热性强,75℃的热水萃取难以将其完全失活,为防止在香蕉果肉中的 PPO在香蕉汁打浆期间引起酶促褐变,需添加0.05%的 L-半胱氨酸或抗坏血酸进行护色。

  6. Biologically inspired LED lens from cuticular nanostructures of firefly lantern.

    Science.gov (United States)

    Kim, Jae-Jun; Lee, Youngseop; Kim, Ha Gon; Choi, Ki-Ju; Kweon, Hee-Seok; Park, Seongchong; Jeong, Ki-Hun

    2012-11-13

    Cuticular nanostructures found in insects effectively manage light for light polarization, structural color, or optical index matching within an ultrathin natural scale. These nanostructures are mainly dedicated to manage incoming light and recently inspired many imaging and display applications. A bioluminescent organ, such as a firefly lantern, helps to out-couple light from the body in a highly efficient fashion for delivering strong optical signals in sexual communication. However, the cuticular nanostructures, except the light-producing reactions, have not been well investigated for physical principles and engineering biomimetics. Here we report a unique observation of high-transmission nanostructures on a firefly lantern and its biological inspiration for highly efficient LED illumination. Both numerical and experimental results clearly reveal high transmission through the nanostructures inspired from the lantern cuticle. The nanostructures on an LED lens surface were fabricated by using a large-area nanotemplating and reconfigurable nanomolding with heat-induced shear thinning. The biologically inspired LED lens, distinct from a smooth surface lens, substantially increases light transmission over visible ranges, comparable to conventional antireflection coating. This biological inspiration can offer new opportunities for increasing the light extraction efficiency of high-power LED packages.

  7. INHIBITION OF RAT LENS ALDOSE REDUCTASE BY QUERCETAGETIN AND PATULETIN

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    In this paper the results of inhibition of the Aldose reductase(AR) activity on Wistar rat lens by Quercetagetin extracted from Tagetes erects Linn and by Patuletin extracted from Tagetes patula Linn are reported.Quercetagetin inhibited AR of the rat lens by 93.9% at 10~(-4)M, 76.0% at 10~(-5)M and 13.3% at 10~(-6)M. Patuletin inhibited AR of the rat lens by 100% at 10~(-1)M, 80% at 10~(-5)M and 22.7% at 10~(-6)M respectively. The results show that these two flavones are lens AR Inhibitors, but further ...

  8. Pars Plana Vitrectomy in Treatment of Lens Injury

    Directory of Open Access Journals (Sweden)

    Remzi Avcı

    2013-01-01

    Full Text Available Lens injury due to traumas may present as loss of capsule integrity, cataract, lens subluxation, or lens luxation. In addition, lens subluxation and lens luxation may occur in pseudophakic patients due to trauma. Clear corneal, scleral or sclero-corneal phacoemulsification surgery, pars plana vitrectomy, pars plana vitrectomy with phaco-fragmentation, or pars plana vitrectomy with removal through corneal incision techniques are used in the treatment of lens injury due to traumas. Intraocular lens can be implanted in the bag, sulcus, or anterior chamber during the surgery. Depending on the circumstances, scleral fixated intraocular lenses or iris-claw lenses may also be preferred. Rehabilitation of such patients is not of a great concern today, with the advanced level of vitreoretinal surgery and cataract surgery techniques and with the current state of technology. (Turk J Ophthalmol 2013; 43: 51-4

  9. System and Method for Null-Lens Wavefront Sensing

    Science.gov (United States)

    Hill, Peter C. (Inventor); Thompson, Patrick L. (Inventor); Aronstein, David L. (Inventor); Bolcar, Matthew R. (Inventor); Smith, Jeffrey S. (Inventor)

    2015-01-01

    A method of measuring aberrations in a null-lens including assembly and alignment aberrations. The null-lens may be used for measuring aberrations in an aspheric optic with the null-lens. Light propagates from the aspheric optic location through the null-lens, while sweeping a detector through the null-lens focal plane. Image data being is collected at locations about said focal plane. Light is simulated propagating to the collection locations for each collected image. Null-lens aberrations may extracted, e.g., applying image-based wavefront-sensing to collected images and simulation results. The null-lens aberrations improve accuracy in measuring aspheric optic aberrations.

  10. Properties of fiber cell plasma membranes isolated from the cortex and nucleus of the porcine eye lens.

    Science.gov (United States)

    Mainali, Laxman; Raguz, Marija; O'Brien, William J; Subczynski, Witold K

    2012-04-01

    The organization and physical properties of the lipid bilayer portion of intact cortical and nuclear fiber cell plasma membranes isolated from the eye lenses of two-year-old pigs were studied using electron paramagnetic resonance (EPR) spin-labeling. Membrane fluidity, hydrophobicity, and the oxygen transport parameter (OTP) were assessed from the EPR spectra of precisely positioned spin labels. Intact cortical and nuclear membranes, which include membrane proteins, were found to contain three distinct lipid environments. These lipid environments were termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain (lipids in protein aggregates). The amount of boundary and trapped lipids was greater in intact nuclear membranes than in cortical membranes. The properties of intact membranes were compared with the organization and properties of lens lipid membranes made of the total lipid extracts from the lens cortex or nucleus. In cortical lens lipid membranes, only one homogenous environment was detected, which was designated as a bulk lipid domain (phospholipid bilayer saturated with cholesterol). Lens lipid membranes prepared from the lens nucleus possessed two domains, assigned as a bulk lipid domain and a cholesterol bilayer domain (CBD). In intact nuclear membranes, it was difficult to discriminate the CBD, which was clearly detected in nuclear lens lipid membranes, because the OTP measured in the CBD is the same as in the domain formed by trapped lipids. The two domains unique to intact membranes-namely, the domain formed by boundary lipids and the domain formed by trapped lipids-were most likely formed due to the presence of membrane proteins. It is concluded that formation of rigid and practically impermeable domains is enhanced in the lens nucleus, indicating changes in membrane composition that may help to maintain low oxygen concentration in this lens region.

  11. Rapid cooled lens cell

    Science.gov (United States)

    Stubbs, David M.; Hsu, Ike C.

    1991-12-01

    This paper describes the optomechanical design, thermal analysis, fabrication, and test evaluation processes followed in developing a rapid cooled, infrared lens cell. Thermal analysis was the key engineering discipline exercised in the design phase. The effect of thermal stress on the lens, induced by rapid cooling of the lens cell, was investigated. Features of this lens cell that minimized the thermal stress will be discussed in a dedicated section. The results of thermal analysis on the selected lens cell design and the selection of the flow channel design in the heat exchanger will be discussed. Throughout the paper engineering drawings, illustrations, analytical results, and photographs of actual hardware are presented.

  12. Pseudophakic hyperopia in nanophthalmic eyes managed by a posterior chamber implantable collamer lens

    Directory of Open Access Journals (Sweden)

    Kothari Kulin

    2011-01-01

    Full Text Available We report a case of a bilateral posterior chamber implantable collamer lens (ICL implantation post-clear lens extraction, to reduce the residual hyperopia, in a patient with nanophthalmic eyes. A 30-year-old female patient, keen to reduce her dependency on glasses and contact lenses, came to our refractive surgery department. Her refractive error was +12.0 and +12.5 diopters in the right and left eye, respectively, with steep corneas on keratometry and a shallow anterior chamber depth. She underwent clear lens extraction with implantation of +35.0 D and +40.0 D IOL in the right eye and left eye, respectively. Her post-operative best-corrected visual acuity was 20/30 with +8.5 D in the right eye and +6 D in the left. She underwent bilateral ICL implantation. Postoperatively after 6 months, her unaided visual acuity was 20/30 in both eyes. In conclusion, ICL implantation can be considered to correct residual hypermetropic ametropia in pseudophakic eyes when other options have limitations.

  13. Iron oxide functionalized graphene oxide as an efficient sorbent for dispersive micro-solid phase extraction of sulfadiazine followed by spectrophotometric and mode-mismatched thermal lens spectrometric determination.

    Science.gov (United States)

    Kazemi, Elahe; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Abbasi, Amir; Rashidian Vaziri, Mohammad Reza; Behjat, Abbas

    2016-01-15

    A simple and rapid dispersive micro-solid phase extraction (DMSPE) combined with mode-mismatched thermal lens spectrometry as well as fiber optic linear array spectrophotometry was developed for the separation, extraction and determination of sulfadiazine. Graphene oxide was synthesized using the modified Hummers method and functionalized with iron oxide nanoparticles by means of a simple one step chemical coprecipitation method. The synthesized iron oxide functionalized graphene oxide was utilized as an efficient sorbent in DMSPE of sulfadiazine. The retained analyte was eluted by using 180µL of a 6:4 mixture of methanol/acetic acid solution and was spectrophotometrically determined based on the formation of an azo dye through coupling with thenoyltrifluoroacetone. Under the optimized conditions, with the application of spectrophotometry technique and with a sample volume of 100mL, the method exhibited a linear dynamic range of 3-80µg L(-1) with a detection limit of 0.82µg L(-1), an enrichment factor of 200 as well as the relative standard deviations of 2.6% and 4.3% (n=6) at 150µg L(-1) level of sulfadiazine for intra- and inter-day analyses, respectively. Whereas, through the application of the thermal lens spectrometry and a sample volume of 10mL, the method exhibited a linear dynamic range of 1-800µg L(-1) with a detection limit of 0.34µg L(-1) and the relative standard deviations of 3.1% and 5.4% (n=6) at 150µg L(-1) level of sulfadiazine for intra- and inter-day analyses, respectively. The method was successfully applied to the determination of sulfadiazine in milk, honey and water samples.

  14. Contact lens in keratoconus

    OpenAIRE

    Varsha M Rathi; Preeji S Mandathara; Srikanth Dumpati

    2013-01-01

    Contact lenses are required for the visual improvement in patients with keratoconus. Various contact lens options, such as rigid gas permeable (RGP) lenses, soft and soft toric lenses, piggy back contact lenses (PBCL), hybrid lenses and scleral lenses are availble. This article discusses about selection of a lens depending on the type of keratoconus and the fitting philosophies of various contact lenses including the starting trial lens. A Medline search was carried out for articles in the En...

  15. Lens regeneration in mice under the influence of vitamin A

    Indian Academy of Sciences (India)

    Digvijay Singh Shekhawat; O P Jangir; Acharya Prakash; Suthar Pawan

    2001-12-01

    The effect of vitamin A has been studied on lens regeneration in young (7 days old) as well as adult mice. A longitudinal slit was made under local anesthesia in the cornea over the lens. The lens was extracted intact through the incision. Intraperitonial injection of vitamin A (0.05 ml of 30 IU/ml in young and 0.05 ml of 50 IU/ml in adult) was given to the operated animals. Vitamin A was found to induce lens regeneration in not only young but also in adult mice. Regenerated lenses were similar in shape, size, transparency and histological features to normal intact lenses.

  16. Image watermarking against lens flare effects

    Science.gov (United States)

    Chotikawanid, Piyanart; Amornraksa, Thumrongrat

    2017-02-01

    Lens flare effects in various photo and camera software nowadays can partially or fully damage the watermark information within the watermarked image. We propose in this paper a spatial domain based image watermarking against lens flare effects. The watermark embedding is based on the modification of the saturation color component in HSV color space of a host image. For watermark extraction, a homomorphic filter is used to predict the original embedding component from the watermarked component, and the watermark is blindly recovered by differentiating both components. The watermarked image's quality is evaluated by wPSNR, while the extracted watermark's accuracy is evaluated by NC. The experimental results against various types of lens flare effects from both computer software and mobile application showed that our proposed method outperformed the previous methods.

  17. Iatrogenic Lens Injuries

    Directory of Open Access Journals (Sweden)

    Ümit Kamış

    2012-12-01

    Full Text Available During intraocular surgery, undesired damages of various etiology may occur in adjacent tissues. One of these tissues is the crystalline lens, which may be traumatized both in anterior segment and posterior segment surgeries, and when damaged, it usually causes marked decrease in visual acuity. The leading causes of iatrogenic lens injuries are intravitreal injection, laser iridotomy, phakic intraocular lens implantation, anterior chamber paracentesis, and vitreoretinal surgery. When crystalline lens damage occurs, its negative effect on visual function may be eliminated by performing cataract surgery intraoperatively or in elective conditions. (Turk J Ophthalmol 2012; 42: Supplement 27-30

  18. Clear cell chondrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R.; David, R.; Cierney, G. III

    1985-01-01

    The clinical, radiologic, and histopathologic features of three cases of clear cell chondrosarcoma are described. On radiographs, this rather benign-appearing tumor resembles a chondroblastoma when it occurs at the end of a long bone, and may occasionally show a calcified matrix. However, it has distinctive tumor cells with a centrally placed vesicular nucleus surrounded by clear cytoplasm. The lesion has a low-grade malignancy and is amenable to en bloc surgical resection, which results in a much better prognosis than that of conventional chondrosarcoma.

  19. Snow-clearing operations

    CERN Document Server

    EN Department

    2010-01-01

    To facilitate snow clearing operations, which commence at 4.30 in the morning, all drivers of CERN cars are kindly requested to park them together in groups. This will help us greatly assist us in our work. Thank-you for your help. Transport Group / EN-HE Tel. 72202

  20. Superlensing Microscope Objective Lens

    CERN Document Server

    Yan, Bing; Parker, Alan; Lai, Yukun; Thomas, John; Yue, Liyang; Monks, James

    2016-01-01

    Conventional microscope objective lenses are diffraction limited, which means that they cannot resolve features smaller than half the illumination wavelength. Under white light illumination, such resolution limit is about 250-300 nm for an ordinary microscope. In this paper, we demonstrate a new superlensing objective lens which has a resolution of about 100 nm, offering at least two times resolution improvement over conventional objectives in resolution. This is achieved by integrating a conventional microscope objective lens with a superlensing microsphere lens using a 3D printed lens adaptor. The new objective lens was used for label-free super-resolution imaging of 100 nm-sized engineering and biological samples, including a Blu-ray disc sample, semiconductor chip and adenoviruses. Our work creates a solid base for developing a commercially-viable superlens prototype, which has potential to transform the field of optical microscopy and imaging.

  1. 婴儿先天性白内障摘除一期人工晶状体植入的研究进展%Primary intraocular lens implantation after extraction of congenital cataract in infants

    Institute of Scientific and Technical Information of China (English)

    刘馨; 罗怡

    2012-01-01

    近年来,婴儿先天性白内障摘除后一期植入人工晶状体受到越来越多眼科医生的认可,并在临床实践中逐步开展.25G玻璃体切除系统在婴儿白内障手术中的应用,大大降低了术后并发症的发生;新型屈光度计算公式和近视漂移预测公式的发展,提高了人工晶状体屈光度选择的准确性;更适合婴幼儿的人工晶状体和弱视训练方法的发展,提升了术后视功能重建的效果.%Primary intraocular lens (IOL) implantation after extraction of congenital cataract in infants has been accepted and gradually applied to clinic by an increasing number of ophthalmologists in recent years.Incidence of postoperative complications has largely reduced after application of the 25-gauge vitrectomy system in cataract surgery in infants.Accuracy of IOL power calculation has been increased because of the developments of new generation of I0L power calculation formula and prediction formula of myopia shift.Visual rehabilitation has improved due to the developments of the infants-suitable IOLs and the means of amblyopia training.

  2. Unitary lens semiconductor device

    Science.gov (United States)

    Lear, Kevin L.

    1997-01-01

    A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

  3. Clearing the Big Smog

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Beijing is trying to clean up its sky with a new standard for vehicle emissions From March 1,Beijing has imple- mented a new stricter vehicle emission standard that could lead to cleaner air,but also force thousands of cars off the road. StandardⅣ,the latest in a series of measures aimed at clearing the per- sistent smog,will match the current standard of the European Union. All the new light petro vehicles that are on sale in the Beijing market shall

  4. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/....

  5. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Lens-Related Eye Infections Mar 01, 2017 New Technology Helps the Legally Blind Be More Independent Oct ... easy answer, and neither one considers long-term impacts. Phakic Intraocular Lenses for Nearsightedness FEB 27, 2017 ...

  6. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ...

  7. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... 2016 More Eye Health News Studies Look at Effects of Marijuana on Vision FEB 28, 2017 By ...

  8. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Healthy Contact Lens Use May 31, 2016 Is El Niño Making Your Allergies Worse? May 16, 2016 ... Number: * Email: * Enter code: * Message: Thank you Your feedback has been sent.

  9. Out-of-the-bag intraocular lens dislocation: outcomes of posterior chamber intraocular lens exchange, risk factors, and prevention

    Institute of Scientific and Technical Information of China (English)

    ZHENG Dan-ying; CHEN Li-na; SUN Yi; SHAO Ying-feng; LIANG Jing-li; LIU Yi-zhi

    2010-01-01

    Background Dislocation of posterior chamber intraocular lens is one of the most common complications of intraocular lens implantation. Lens exchange is an effective solution to this unsatisfactory status. This study was conducted to analyze the possible predisposing factors for out-of-the-bag posterior chamber intraocular lens dislocation and to study the outcomes of lens exchange surgery.Methods Thirty-six consecutive patients (36 eyes) with out-of-the-bag intraocular lens dislocation who underwent posterior chamber intraocular lens exchange in Zhongshan Ophthalmic Center of Sun Yat-sen University (Guangdong,China) from January 2003 to October 2009 were included. A 6-month follow-up was completed. The causes for out-of-the-bag intraocular lens dislocation and visual outcomes of posterior chamber intraocular lens exchange were analyzed. The out-of-the-bag intraocular lens dislocation was diagnosed on the basis of the findings from slit-lamp microscope and B-ultrasound. The dislocated intraocular lens was explanted. Reimplantation of a new posterior chamber intraocular lens was performed in each case using standardized surgical procedures.Results In this study, a total of thirty-six consecutive patients (36 eyes) with out-of-the-bag intraocular lens dislocation underwent posterior chamber intraocular lens exchange surgery. Causes for out-of-the-bag intraocular lens dislocation included posterior capsule rupture during the initial cataract extraction procedure (23 eyes, 63.8%), trauma (5 eyes,13.9%), neodymium-doped yttrium aluminium garnet (Nd:YAG) laser-induced dislocation (2 eyes, 5.6%), the status after vitrectomy (2 eyes, 5.6%) and unidentifiable etiology (4 eyes, 11.1%). Symptoms of these patients mainly included decrease in visual acuity (17 cases, 47.2%), blurred vision (16 cases, 44.4%), glare (1 case, 2.8%), diplopia (1 case,2.8%), and halo (1 case, 2.8%). Intraocular lens dislocation into the posterior vitreous cavity (29 eyes, 80.5%), anterior chamber (1

  10. Consciousness CLEARS the mind.

    Science.gov (United States)

    Grossberg, Stephen

    2007-11-01

    A full understanding of consciousness requires that we identify the brain processes from which conscious experiences emerge. What are these processes, and what is their utility in supporting successful adaptive behaviors? Adaptive Resonance Theory (ART) predicted a functional link between processes of Consciousness, Learning, Expectation, Attention, Resonance and Synchrony (CLEARS), including the prediction that "all conscious states are resonant states". This connection clarifies how brain dynamics enable a behaving individual to autonomously adapt in real time to a rapidly changing world. The present article reviews theoretical considerations that predicted these functional links, how they work, and some of the rapidly growing body of behavioral and brain data that have provided support for these predictions. The article also summarizes ART models that predict functional roles for identified cells in laminar thalamocortical circuits, including the six layered neocortical circuits and their interactions with specific primary and higher-order specific thalamic nuclei and nonspecific nuclei. These predictions include explanations of how slow perceptual learning can occur without conscious awareness, and why oscillation frequencies in the lower layers of neocortex are sometimes slower beta oscillations, rather than the higher-frequency gamma oscillations that occur more frequently in superficial cortical layers. ART traces these properties to the existence of intracortical feedback loops, and to reset mechanisms whereby thalamocortical mismatches use circuits such as the one from specific thalamic nuclei to nonspecific thalamic nuclei and then to layer 4 of neocortical areas via layers 1-to-5-to-6-to-4.

  11. Intraocular Lens Calcification; a Clinicopathologic Report

    Directory of Open Access Journals (Sweden)

    Mozhgan Rezaei-Kanavi

    2009-04-01

    Full Text Available

    PURPOSE: To describe the clinical and pathological features of a case of hydrogel intraocular lens (IOL calcification. CASE REPORT: A 48-year-old man underwent explantation of a single-piece hydrophilic acrylic intraocular lens in his left eye because of decreased visual acuity and milky white opalescence of the IOL. The opacified lens was exchanged uneventfully with a hydrophobic acrylic IOL. Gross examination of the explanted IOL disclosed opacification of the optic and haptics. Full-thickness sections of the lens optic were stained with hematoxylin and eosin (H&E, von Kossa and Gram Tworts'. Microscopic examination of the sections revealed fine and diffuse basophilic granular deposits of variable size within the lens optic parallel to the lens curvature but separated from the surface by a moderately clear zone. The deposits were of high calcium content as evident by dark brown staining with von Kossa. Gram Tworts' staining disclosed no microorganisms. CONCLUSION: This report further contributes to the existing literature on hydrogel IOL calcification.

  12. Late opacification of a hydrophilic acrylic intraocular lens

    Directory of Open Access Journals (Sweden)

    Al-Bdour Muawyah

    2008-01-01

    Full Text Available Cataract extraction and intraocular lens implantation is considered to be a safe procedure in most cases. However, the new advances in the surgical technique namely phacoemulsification and hence the increased use of foldable intraocular lenses have given rise to new complications including late opacification of intraocular lenses. In this case we report late opacification of a foldable hydrophilic acrylic intraocular lens and the surgical technique for its exchange.

  13. Thin Lens Ray Tracing.

    Science.gov (United States)

    Gatland, Ian R.

    2002-01-01

    Proposes a ray tracing approach to thin lens analysis based on a vector form of Snell's law for paraxial rays as an alternative to the usual approach in introductory physics courses. The ray tracing approach accommodates skew rays and thus provides a complete analysis. (Author/KHR)

  14. Use of Digital Image Technology to 'Clearly' Depict Global Change

    Science.gov (United States)

    Molnia, B. F.; Carbo, C. L.

    2014-12-01

    Earth is dynamic and beautiful. Understanding why, when, how, and how fast its surface changes yields information and serves as a source of inspiration. The artistic use of geoscience information can inform the public about what is happening to their planet in a non-confrontational and apolitical way. While individual images may clearly depict a landscape, photographic comparisons are necessary to clearly capture and display annual, decadal, or century-scale impacts of climate and environmental change on Earth's landscapes. After years of effort to artistically communicate geoscience concepts with unenhanced individual photographs or pairs of images, the authors have partnered to maximize this process by using digital image enhancement technology. This is done, not to manipulate the inherent artistic content or information content of the photographs, but to insure that the comparative photo pairs produced are geometrically correct and unambiguous. For comparative photography, information-rich historical photographs are selected from archives, websites, and other sources. After determining the geographic location from which the historical photograph was made, the original site is identified and eventually revisited. There, the historical photos field of view is again photographed, ideally from the original location. From nearly 250 locations revisited, about 175 pairs have been produced. Every effort is made to reoccupy the original historical site. However, vegetation growth, visibility reduction, and co-seismic level change may make this impossible. Also, inherent differences in lens optics, camera construction, and image format may result in differences in the geometry of the new photograph when compared to the old. Upon selection, historical photos are cleaned, contrast stretched, brightness adjusted, and sharpened to maximize site identification and information extraction. To facilitate matching historical and new images, digital files of each are overlain in

  15. Flat acoustic lens by acoustic grating with curled slits

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Pai; Xiao, Bingmu; Wu, Ying, E-mail: ying.wu@kaust.edu.sa

    2014-10-03

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry–Perot resonance. - Highlights: • Expression of transmission coefficient of an acoustic grating with curled slits. • Non-dispersive and tunable effective medium parameters for the acoustic grating. • A flat acoustic focusing lens with gradient index by using the acoustic grating.

  16. Analysis of the efficacy of traumatic cataract extraction and intraocular lens implantation%外伤性白内障摘出人工晶状体植入术效果分析

    Institute of Scientific and Technical Information of China (English)

    田波新

    2015-01-01

    目的:分析外伤性白内障手术摘出人工晶状体植入的手术效果。方法外伤性白内障手术60例(60眼)。其中39例行Ⅰ期IOL植入,21例行Ⅱ期IOL植入。结果Ⅰ期与Ⅱ期IOL植入,手术后视力均有明显提高,两者术后视力提高程度的差异无统计学意义(P=0.230~1.124)。术中并发症主要是后囊破裂及玻璃体脱出,术后并发症有角膜水肿、虹膜睫状体炎和后囊浑浊。结论IOL植入是治疗外伤性白内障,提高视力的有效方法,虽然Ⅰ期IOL植入术后并发症较Ⅱ期人工晶状体植入术后高,但经过及时有效的治疗都能得以恢复,且避免了二次手术。%Objective To analyse the efficacy of traumatic cataract extraction and intraocular lens (IOL)implantation. Methods Sixty eyes of 60 cases of traumatic cataract were enrolled,among which 39 patients received IOL implantation at stage I, and another 21 cases received IOL implantation at stageⅡ. Results After the IOL implantation surgery, the vision of patients in both groups were significantly improved, and the differences in improved vision level between two groups was not statistically significant (P=0. 230 ~1. 124). Additionally,the intraoperative complications were mainly posterior capsule rupture and vitreous loss, while postoperative complications included corneal edema, iridocyclitis, and posterior capsular opacification. Conclusion IOL implantation is an effective way to treat traumatic cataract and improve vision. Although the postoperative complications of IOL implantation at stage I were more than that of stageⅡ,they all could recover after timely and effective treatment which avoid the second surgery.

  17. 无粘弹剂小切口白内障摘除加人工晶体植入术156例临床疗效观察%Effect of no viscoelastic small incision cataract extraction plus intraocular lens implantation

    Institute of Scientific and Technical Information of China (English)

    庞永明; 尼亚美

    2011-01-01

    Objective To evaluate non-viscoelastic small incision extracapsular cataract extraction plus intraocular lens implantation in cataract surgery on Africans. Methods 156 cases (156 eyes) black cataract patients without viscoelastic were treated with small incision extracapsular cataract extraction plus intraocular lens implantation. Results The visual acuity≥0. 3 after 1 week were 71. 8% (112). The visual acuity ≥1. 0 accounted for 11. 5% (18). The visual acuity ≥0. 3 after 3 months accounted for 93. 6% (146). The visual acuity ≥1. 0 was 15. 4% (24). Conclusion It is effective to treated African cataract with non-viscoelastic small incision extracapsular cataract extraction plus intraocular lens implantation.%目的 探讨无粘弹剂小切口白内障囊外摘除加人工晶体植入术在治疗非洲黑人白内障的临床疗效.方法 对156例(156眼)黑人白内障患者行无粘弹剂小切口白内障囊外摘除加人工晶体植入术,并评估疗效.结果 术后1周视力≥0.3者占71.8%(112眼),视力≥1.0者占11.5%(18眼).3个月后视力≥0.3者占93.6%(146眼),视力≥1.0者占15.4%(24眼).结论 无粘弹剂小切口白内障囊外摘除及人工晶体植入术损伤小,术后视力恢复好.在非洲地区有推广应用价值.

  18. Interdisciplinarity as a Lens for Theorizing Language/Content Partnerships

    Science.gov (United States)

    Paretti, Marie C.

    2011-01-01

    The paper employs interdisciplinarity as a theoretical lens for describing meaningful content/ language partnerships and establishing an ontology for such partnerships. Interdisciplinary collaboration, as defined by scholars, entails the integration of knowledge across domains and the clear valuing of all contributors in addressing an issue…

  19. 超声乳化联合人工晶体植入术治疗闭角型青光眼合并白内障临床观察%Cataract extraction combined with intraocular lens implantation for the treatment of angle closure glaucoma with cataract clinical observation

    Institute of Scientific and Technical Information of China (English)

    胡开东

    2012-01-01

    Objective Observation of cataract extraction with intraocular lens implantation forangle closure glaucoma patients with cataract treatment. Methods A retrospective analysis from June 2008 to April 2010 54 cases of angle-closure glaucoma and cataract patients, the implementation of cataract surgery and intraocular lens implantation (phacoemulsification in 31 cases, a small incision extracapsular cataract extraction 23 cases). Follow-up period of 1 month to 1 year. Results Postoperative visual acuity improved to varying degrees, intraocular pressure control in 11 ~20mmHg. Anterior chamber deepened, widened to varying degreesangle. Conclusion Cataract surgery and intraocular lens implantation can be effective in treating angle-closure glaucoma and cataract patients.%目的 观察白内障摘除联合人工晶体植入术治疗闭角型青光眼合并白内障的患者的疗效.方法 回顾性分析2008年6月~2010年4月54例闭角型青光眼合并白内障患者,实施白内障摘除术联合人工晶体植入术(超声乳化术31例,小切口囊外摘除术23例)的疗效.结果 术后视力不同程度提高,眼压控制在11~20mmHg,前房加深,房角不同程度增宽.结论 白内障摘除术联合人工晶体植入术可有效治疗闲角型青光眼合并白内障的患者.

  20. LASER INDUCED THERMAL LENS EFFECT

    Institute of Scientific and Technical Information of China (English)

    沈俊; 黄孟才; 江景云; 施教芳

    1991-01-01

    The thermal lens effect has emerged in recent years as a novel ,highly sensitive tool for the study of the very weak molecular absorption of light energy,This paper discusses the theory and technique of the thermal lens measurement.Some opplications of the thermal lens measurement are described.A mode-mismatched dual-beam thermal lens experimental arragement with a modulated probe beam ,designed by the authors.for trace analysis is presented,and its detection limit was found to be 4.1×10-7 for Cu(Ⅱ) in ethanol and 80 mW excitation power.

  1. Clinical analysis of delayed onset postoperative uveitis after cataract extraction with intraocular lens implantation%白内障摘出人工晶状体植入术后迟发性葡萄膜炎的临床分析

    Institute of Scientific and Technical Information of China (English)

    赵才; 楚松峰; 王磊

    2011-01-01

    Objective To investigate the pathogenesis and related factors of delayed uveitis after cataract extraction intraocular lens (IOL) implantation surgery.Methods 27 eyes of delayed uveitis in 545 age-related cataract cases,15 cases of delayed uveitis in 92 cases with diabetic cataract,11 cases of delayed uveitis in 73 cases of child and adolescent cataract were retrospectively analyzed.Age-related cataract,diabetic cataract,children cataract were divided into group A,group B and group C.We compared the rates of delayed uveitis of group A with group B,and group A with group C to see if it has statistically significant difference,using statistical methods x2inspection comparison.Results The rates of delayed uveitis between age-related cataract and diabetic cataract was statistically significantly different (P < 0.0l ),the rates of delayed uveitis between age-related cataract and children cataract was statistically significantly different ( P < 0.01 ).Conclusion Diabetes and younger are considered as the factors of delayed uveitis.The prognosis depends on the early treatment.%目的 探讨白内障人工晶体植入术后出现的迟发性葡萄膜炎的发病机制及其相关影响因素.方法 系统性同顾545例(596眼)年龄相关性白内障摘出术后迟发性葡萄膜反应27眼;糖尿病性的白内障92例(92眼),术后迟发性葡萄膜反应15眼;青少年儿童白内障73例(73眼),术后迟发性葡萄膜反应11眼.将年龄相关性白内障、糖尿病性白内障、青少年儿童白内障依次分作A组、B组和C组,比较A组与B组、A组与C组间术后迟发性葡萄膜炎的发病情况差异.结果 年龄相关性白内障术后迟发性葡萄膜反应发生率为4.53%与糖尿病性白内障术后发生率(16.38%)之间差异有统计学意义(P<0.01);与青少年儿童白内障术后发生率(15.07%)之间差异也有统计学意义(P<0.01).结论 青少年儿童白内障、糖尿病性白内障患者人工晶状体植

  2. Physics of electrostatic lens

    Science.gov (United States)

    1981-09-01

    The purpose of this program was to study the physics of the ion-energy boosting electrostatic lens for collective ion acceleration in the Luce diode. Extensive work was done in preparation for experiments on the PI Pulserad 1150. Analytic work was done on the orbit of protons in a mass spectrometer and a copper stack for nuclear activation analysis of proton energy spectrum has been designed. Unfortunately, a parallel program which would provide the Luce diode for the collective ion acceleration experiment never materialized. As a result no experiments were actually performed on the Pulserad 1150.

  3. [Intraocular lens implantation in developmental lens disorders in children].

    Science.gov (United States)

    Kanigowska, Krystyna; Grałek, Mirosława; Kepa, Beata; Chipczyńska, Barbara

    2009-01-01

    The pediatric cataract surgery in eyes with developmental disorders, stay with still considerable challenge. At children, the lasting vision development extorts necessity quick settlement of refraction defect formed after operation. The intraocular lens old boy with cataract in microspherophakia and 12 years old boy with cataract in lens with coloboma. One-piece flexible and rigid PMMA intraocular lens was placed with success at posterior chamber without scleral fixations and without using capsular tension ring in this cases. After 3 years of observation there were no decentration or dislocation of intraocular lens in both children. Authors concluded that in some cases posterior chamber intraocular lens implantation despite defective zonular or capsular support, can make up the effective method of surgical treatment without risk of early dislocation.

  4. Media Language, Clear or Obscure

    DEFF Research Database (Denmark)

    Jakobsen, Bjarne le Fevre; Ejstrup, Michael

    2015-01-01

    Abstract— Be clear, not obscure. One of the four maxims for optimal communication is that it is essential to develop proficiency in being concise and clear. The question is whether this is really a good idea in all contexts. There is some evidence to the contrary. Undoubtedly, we have many contex...... for the survival of free speech....... growth in diversity, means that media need to be very cognizant of the stringency with which they handle the advice to be linguistically clear and concise. The need to pay great attention to situational awareness is highly visible and intrusive. Attention to situational awareness seems to be crucial...

  5. Lens regeneration in juvenile and adult rabbits measured by image analysis.

    Science.gov (United States)

    Gwon, A E; Jones, R L; Gruber, L J; Mantras, C

    1992-06-01

    Secondary cataract growth commonly occurs after extracapsular cataract extraction. The proliferation of this regrowth occurs at rates related to many factors. In this study, the authors analyzed the amount of lens regeneration after endocapsular lens extraction that leaves the anterior and posterior capsules relatively intact. The analysis was performed in New Zealand albino rabbits with the aid of image analysis measurements in young and adult animals. The effect of low vacuum suction of the anterior capsule on the growth was determined. Lens regeneration was used as a measure of the growth potential of the leftover epithelial cells in the capsule bag. The results showed that lens regeneration was significantly faster in younger rabbits. However, low vacuum suction had no effect on the growth rate. Potential therapeutic agents for preventing secondary cataracts may be better analyzed with image analysis processing of lens regeneration, a precise and rapid measurement technique.

  6. Development of a novel mixed hemimicelles dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene for the separation and preconcentration of fluoxetine in different matrices before its determination by fiber optic linear array spectrophotometry and mode-mismatched thermal lens spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kazemi, Elahe; Haji Shabani, Ali Mohammad [Department of Chemistry, Yazd University, Safaieh, 89195-741, Yazd (Iran, Islamic Republic of); Dadfarnia, Shayessteh, E-mail: sdadfarnia@yazd.ac.ir [Department of Chemistry, Yazd University, Safaieh, 89195-741, Yazd (Iran, Islamic Republic of); Abbasi, Amir [Department of Physics, Yazd University, Safaieh, 89195-741, Yazd (Iran, Islamic Republic of); Rashidian Vaziri, Mohammad Reza [Laser and Optics Research School, 14155-1339, Tehran (Iran, Islamic Republic of); Behjat, Abbas [Department of Physics, Yazd University, Safaieh, 89195-741, Yazd (Iran, Islamic Republic of)

    2016-01-28

    This study aims at developing a novel, sensitive, fast, simple and convenient method for separation and preconcentration of trace amounts of fluoxetine before its spectrophotometric determination. The method is based on combination of magnetic mixed hemimicelles solid phase extraction and dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene as a sorbent. The magnetic graphene was synthesized by a simple coprecipitation method and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The retained analyte was eluted using a 100 μL mixture of methanol/acetic acid (9:1) and converted into fluoxetine-β-cyclodextrin inclusion complex. The analyte was then quantified by fiber optic linear array spectrophotometry as well as mode-mismatched thermal lens spectroscopy (TLS). The factors affecting the separation, preconcentration and determination of fluoxetine were investigated and optimized. With a 50 mL sample and under optimized conditions using the spectrophotometry technique, the method exhibited a linear dynamic range of 0.4–60.0 μg L{sup −1}, a detection limit of 0.21 μg L{sup −1}, an enrichment factor of 167, and a relative standard deviation of 2.1% and 3.8% (n = 6) at 60 μg L{sup −1} level of fluoxetine for intra- and inter-day analyses, respectively. However, with thermal lens spectrometry and a sample volume of 10 mL, the method exhibited a linear dynamic range of 0.05–300 μg L{sup −1}, a detection limit of 0.016 μg L{sup −1} and a relative standard deviation of 3.8% and 5.6% (n = 6) at 60 μg L{sup −1} level of fluoxetine for intra- and inter-day analyses, respectively. The method was successfully applied to determine fluoxetine in pharmaceutical formulation, human urine and environmental water samples. - Graphical abstract: A novel, sensitive, fast, simple and convenient mixed hemimicelles

  7. Sushruta in 600 B.C. introduced extraocular expulsion of lens material.

    Science.gov (United States)

    Grzybowski, Andrzej; Ascaso, Francisco J

    2014-03-01

    It is generally accepted that Jacques Daviel introduced in the 18th century the extracapsular technique of extraction of the lens while the couching method of cataract operation had already been practiced since ancient times. Present study analyses the first known cataract surgery description in three translations into English from the original Sanskrit Sushruta textbook and all the available literature on the subject. We found evidences that some sort of extraocular expulsion of lens material through a limbal puncture (paracentesis) was described by the Indian surgeon. Nevertheless, this incision cannot be considered as a classic extracapsular procedure because it was not large enough to allow the extraction of the entire lens.

  8. Optical clearing at cellular level

    Science.gov (United States)

    Kinnunen, Matti; Bykov, Alexander V.; Tuorila, Juho; Haapalainen, Tomi; Karmenyan, Artashes V.; Tuchin, Valery V.

    2014-07-01

    Strong light scattering in tissues and blood reduces the usability of many optical techniques. By reducing scattering, optical clearing enables deeper light penetration and improves resolution in several optical imaging applications. We demonstrate the usage of optical tweezers and elastic light scattering to study optical clearing [one of the major mechanisms-matching of refractive indices (RIs)] at the single particle and cell level. We used polystyrene spheres and human red blood cells (RBCs) as samples and glycerol or glucose water solutions as clearing agents. Optical tweezers kept single microspheres and RBCs in place during the measurement of light scattering patterns. The results show that optical clearing reduces the scattering cross section and increases g. Glucose also decreased light scattering from a RBC. Optical clearing affected the anisotropy factor g of 23.25-μm polystyrene spheres, increasing it by 0.5% for an RI change of 2.2% (20% glycerol) and 0.3% for an RI change of 1.1% (13% glucose).

  9. Delayed Hyphema after Posterior Chamber Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    A56-year-old man with senile cataract in the left eye underwent extracapsularcataract extraction(ECCE)and posteriorchamber intraocular lens(IOL)implanta-tion on December 19,1988.A 13D J-loopplannar lens was inserted in the ciliary sul-cus.The operation was successful with mildpostoperative response.His corrected visionwas 20/20. He had a follow-up examination onMarch 20,1989.No complication was notedand his vision retained 20/20.In theevening of the same day,the patient sud-denly felt discomfortable and...

  10. The control of aniseikonia after intraocular lens implantation.

    Science.gov (United States)

    Hillman, J S; Hawkswell, A

    1985-01-01

    This paper reports a study of postoperative refraction and eikonometry of 50 patients who had unilateral cataract extraction with implantation of a pupil-supported intraocular lens. The mean postoperative aniseikonia (+/- SD) was 1.97 (+/- 1.82). A statistically significant relationship was shown between anisometropia and aniseikonia. Despite aniseikonia of up to 7.8 per cent there were no diplopia problems as the visual system exhibits a high degree of tolerance. It is concluded that aniseikonia can be controlled to within clinically acceptable limits by the simple calculation of intraocular lens power for isometropia.

  11. The Deep Lens Survey

    CERN Document Server

    Wittman, D; Dell'Antonio, I P; Becker, A C; Margoniner, V E; Cohen, J; Norman, D; Loomba, D; Squires, G; Wilson, G; Stubbs, C; Hennawi, J F; Spergel, D N; Boeshaar, P C; Clocchiatti, A; Hamuy, M; Bernstein, G; González, A; Guhathakurta, R; Hu, W; Seljak, U; Zaritsky, D

    2002-01-01

    The Deep Lens Survey (DLS) is a deep BVRz' imaging survey of seven 2x2 degree fields, with all data to be made public. The primary scientific driver is weak gravitational lensing, but the survey is also designed to enable a wide array of other astrophysical investigations. A unique feature of this survey is the search for transient phenomena. We subtract multiple exposures of a field, detect differences, classify, and release transients on the Web within about an hour of observation. Here we summarize the scientific goals of the DLS, field and filter selection, observing techniques and current status, data reduction, data products and release, and transient detections. Finally, we discuss some lessons which might apply to future large surveys such as LSST.

  12. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  13. 右美托咪定对晶状体摘出术后小鼠认知功能的作用%Effect of Dexmedetomidine on cognitive function after lens extraction in mice

    Institute of Scientific and Technical Information of China (English)

    杨丽华; 郝尚臣; 徐玉灿; 李志松; 张卫

    2015-01-01

    Objective To investigate the effect of Dexmedetomidine (Dex) on long-term cognitive function after extracapsular lens extraction (ECLE) in mice.Methods Forty adult male C57BL/6J mice were randomly divided into control group (C group),ECLE group,normal saline group (NS group) and Dex group with 10 mice in each group.Three days after ECLE model was made,the mouse in C group and ECLE group underwent Morris water maze test,then they were euthanized and hippocampus tissue was immediately excised for determination of wet weight to dry weight (W/D) and total water content (TWC).The transcription levels of cycteinyl aspirate-specific protease-12 (caspase-12) mRNA and its protein in hippocampus tissue were detected respectively by reverse transcription polymerase chain reaction (PCR) and Western Blot.Apoptosis index (AI) of hippocampus tissue was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay.After the mice regained consciousness post the operation,animals received intraperitoneally Dex at a dose of 25 μg · kg-1 · d-1 for 30 consecutive days in Dex group.Animals of NS group were accepted intraperitoneally injection with the same volume of normal saline.The evaluation indexes mentioned above were programmed at 30 dyas post intraperitonedlly injection.Results Compared with C group,the escape latency and swimming distance were prolonged transcription in ECLE group (both P < 0.05),the value of W/D,TWC and AI were increased (all P < 0.05),and the expression of caspase-12 and mRNA transcription in hippocampus tissue were significantly higher (both P < 0.05) in ECLE group.Compared with NS group,the escape latency and swimming distance were shortened in Dex group(both P < 0.05),the value of W/D,TWC and AI were decreased (all P < 0.05),and the expression of caspase-12 and mRNA protein transcription in hippocampus tissue were significantly lower (both P < 0.05) in Dex group.Conclusion The treatment of Dex could improve the

  14. Transferring Lens Prescriptions Between Lens-Design Programs

    Science.gov (United States)

    Stacy, John E.; Wooley, Laura; Carlin, Brian

    1989-01-01

    Optical Lens Prescription Data Formatter computer program enables user to transfer complicated lens prescriptions quickly and easily from one major optical-design program to another and back again. One can take advantage of inherent strength of either program. Programs are ACCOS V from Scientific Calculations, Inc., of Fishers, NY, and CODE V from Optical Research Associates of Pasadena, CA. VAX version written in FORTRAN.

  15. [Intraocular lenses for the correction of refraction errors. Part II. Phakic posterior chamber lenses and refractive lens exchange with posterior chamber lens implantation].

    Science.gov (United States)

    Kohnen, T; Kasper, T; Terzi, E

    2005-11-01

    In this overview, the current status of intraocular lens surgery to correct refractive error is reviewed. The interventions are divided into additive surgery with intraocular lens implantation without extraction of the crystalline lens (phakic intraocular lens, PIOL) or removal of the crystalline lens with implantation of an IOL (refractive lens exchange, RLE). Phakic IOLs are constructed as angle-supported or iris-fixated anterior chamber lenses and posterior chamber lenses which are fixated in the ciliary sulcus. The implantation of phakic IOLs has been demonstrated to be an effective, safe, predictable and stable procedure to correct higher refractive errors. Complications are rare and differ for the three types of PIOL; for posterior chamber lenses these are mainly cataract formation and pigment dispersion. RLE is preferable in cases of high ametropia in which the natural lens has lost its accommodative effect. The main complications for myopic RLA include retinal detachment, while hyperopic refractive lens exchange may be associated with surgical problems in the narrower anterior eye segment.

  16. Experimental study on cyclosporine A drug delivery system in prevention of posterior capsule opacification after intraocular lens implantation in rabbits

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective To study the effect of cyclosporine A drug delivery system (CsA-DDS) on the prevention of posterior capsule opacification (PCO) after experimental intraocular lens implantation in rabbit eyes. Methods Twenty healthy New Zealand white rabbits, whose left eyes and right eyes were used respectively as experiment eyes and controls, were subjected to extracapsular lens extraction and artificial lens implantation. During the operation, CsA-DDS with poly (lactideco-glycolide) as carriers or empty DDS was...

  17. Lens siderosis resulting from a small intralenticular metallic foreign body

    Directory of Open Access Journals (Sweden)

    Shah, Mehul A.

    2015-11-01

    Full Text Available We report a rare case of lens siderosis with an undetectable intraocular foreign body by imaging. An 8-year-old boy presented with diminution of vision in the left eye since 3 months. His parents gave a preceding uncertain history of a foreign body injury to his left eye 3 months ago while playing. Presenting visual acuity in the left eye was perception of hand movements. Slit-lamp examination revealed a total white cataract with brownish-pigmented spots on the anterior capsule of the lens, but no intraocular foreign body was found. There was also no evidence of an intraocular foreign body on ultrasonography. Patient underwent cataract extraction with intraocular lens implantation. During the operation, a small (2×1×1 mm in size intralenticular foreign body of metal material was found and removed carefully with a magnet. The patient regained 20/30 vision after surgery.

  18. An integral-field spectroscopic strong lens survey

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, Adam S [Harvard-Smithsonian Center for Astrophysics, 60 Garden St. MS-20, Cambridge, MA 02138 (United States); Burles, Scott [Department of Physics and Kavli Institute, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2007-12-15

    We present the observational results of a survey for strong gravitational lens systems consisting of extended emission-line galaxies lensed by intervening early-type galaxies, conducted using integral field units (IFUs) of the Magellan IMACS and Gemini GMOS-N spectrographs. These data are highly valuable for corroborating the lensing interpretation of Hubble Space Telescope imaging data. We show that in many cases, ground-based IFU spectroscopy is in fact competitive with space-based imaging for the measurement of the mass model parameters of the lensing galaxy. We demonstrate a novel technique of three-dimensional gravitational lens modeling for a single lens system with a resolved lensed rotation curve. We also describe the details of our custom IFU data analysis software, which performs optimal multi-fiber extraction, relative and absolute wavelength calibration to a few hundredths of a pixel RMS and nearly Poisson-limited sky subtraction.

  19. An electrostatic deceleration lens for highly charged ions.

    Science.gov (United States)

    Rajput, J; Roy, A; Kanjilal, D; Ahuja, R; Safvan, C P

    2010-04-01

    The design and implementation of a purely electrostatic deceleration lens used to obtain beams of highly charged ions at very low energies is presented. The design of the lens is such that it can be used with parallel as well as diverging incoming beams and delivers a well focused low energy beam at the target. In addition, tuning of the final energy of the beam over a wide range (1 eV/q to several hundred eV/q, where q is the beam charge state) is possible without any change in hardware configuration. The deceleration lens was tested with Ar(8+), extracted from an electron cyclotron resonance ion source, having an initial energy of 30 keV/q and final energies as low as 70 eV/q have been achieved.

  20. Investigation into photostability of soybean oils by thermal lens spectroscopy.

    Science.gov (United States)

    Savi, E L; Malacarne, L C; Baesso, M L; Pintro, P T M; Croge, C; Shen, J; Astrath, N G C

    2015-06-15

    Assessment of photochemical stability is essential for evaluating quality and the shelf life of vegetable oils, which are very important aspects of marketing and human health. Most of conventional methods used to investigate oxidative stability requires long time experimental procedures with high consumption of chemical inputs for the preparation or extraction of sample compounds. In this work we propose a time-resolved thermal lens method to analyze photostability of edible oils by quantitative measurement of photoreaction cross-section. An all-numerical routine is employed to solve a complex theoretical problem involving photochemical reaction, thermal lens effect, and mass diffusion during local laser excitation. The photostability of pure oil and oils with natural and synthetic antioxidants is investigated. The thermal lens results are compared with those obtained by conventional methods, and a complete set of physical properties of the samples is presented.

  1. Investigation into photostability of soybean oils by thermal lens spectroscopy

    Science.gov (United States)

    Savi, E. L.; Malacarne, L. C.; Baesso, M. L.; Pintro, P. T. M.; Croge, C.; Shen, J.; Astrath, N. G. C.

    2015-06-01

    Assessment of photochemical stability is essential for evaluating quality and the shelf life of vegetable oils, which are very important aspects of marketing and human health. Most of conventional methods used to investigate oxidative stability requires long time experimental procedures with high consumption of chemical inputs for the preparation or extraction of sample compounds. In this work we propose a time-resolved thermal lens method to analyze photostability of edible oils by quantitative measurement of photoreaction cross-section. An all-numerical routine is employed to solve a complex theoretical problem involving photochemical reaction, thermal lens effect, and mass diffusion during local laser excitation. The photostability of pure oil and oils with natural and synthetic antioxidants is investigated. The thermal lens results are compared with those obtained by conventional methods, and a complete set of physical properties of the samples is presented.

  2. Study on effects of cataract extraction combined with intraocular lens implantation for treating angle-closure glaucoma%白内障摘除联合人工晶体植入治疗闭角型青光眼的疗效探讨

    Institute of Scientific and Technical Information of China (English)

    杨宇红; 李立刚; 高作书; 傅刚; 郭小博

    2015-01-01

    目的:探讨白内障摘除联合人工晶体植入的手术方式治疗闭角型青光眼合并白内障的疗效。方法将收治的白内障合并闭角型青光眼的患者108例(126眼)随机分成对照组和观察组,对照组选择白内障摘除联合人工晶体植入术联合小梁切除术进行治疗,观察组选择白内障摘除联合人工晶体植入术进行治疗,对两组的治疗效果数据进行分析。结果治疗后,观察组患者视力的提高明显高于对照组,差异有统计学意义(P<0.05)。观察组的眼压由(25.29±5.33)mm Hg降至(14.23±4.11)mm Hg ,对照组的眼压由(25.74±5.12)mm Hg降至(14.36±4.02)mmHg ,两组眼压均有明显降低。观察组术后并发症的发生率(12.5%)明显低于对照组(37.1%)。结论白内障摘除联合人工晶体植入治疗闭角型青光眼合并白内障,能够有效提高患者的治疗效果及生活质量,可作为临床较为理想的治疗白内障合并青光眼的方案之一。%Objective To investigate the effect of cataract extraction combined with intraocular lens implanta‐tion for treating cataract complicating angle‐closure glaucoma .Methods 108 cases (126 eyes) of cataract complica‐ting angle‐closure glaucoma were allocated into the control group and the observation group .The control group was treated with cataract extraction combined with intraocular lens implantation and trabeculectomy ,while the observa‐tion group was treated with cataract extraction combined with intraocular lens implantation .The treatment effects were analyzed and compared between the two groups .Results The vision improvement after treatment in the obser‐vation group was obviously higher than that in the control group ,and the difference was statistically significant .The intraocular pressuregop(IOP) in the obserration group was decreased from (25 .29 ± 5 .33)mm Hg to (14 .23 ± 4 .11) mm Hg .IOP

  3. The art of thinking clearly

    CERN Document Server

    Dobelli, Rolf

    2013-01-01

    The Art of Thinking Clearly by world-class thinker and entrepreneur Rolf Dobelli is an eye-opening look at human psychology and reasoning — essential reading for anyone who wants to avoid “cognitive errors” and make better choices in all aspects of their lives. Have you ever: Invested time in something that, with hindsight, just wasn’t worth it? Or continued doing something you knew was bad for you? These are examples of cognitive biases, simple errors we all make in our day-to-day thinking. But by knowing what they are and how to spot them, we can avoid them and make better decisions. Simple, clear, and always surprising, this indispensable book will change the way you think and transform your decision-making—work, at home, every day. It reveals, in 99 short chapters, the most common errors of judgment, and how to avoid them.

  4. Writing clear animal activity proposals.

    Science.gov (United States)

    Pinson, David M

    2011-06-01

    Although IACUC-related topics are frequently discussed in the literature, there is little published information about how to write animal activity proposals. In this article, the author discusses key considerations in the writing and review of animal activity proposals. The author then describes a framework for developing and writing clear animal activity proposals that highlight animal welfare concerns. Though these recommendations are aimed at individuals writing and reviewing research proposals, the framework can be modified for other types of animal activity proposals.

  5. Nanoceria have no genotoxic effect on human lens epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pierscionek, Barbara K; Yasseen, Akeel A [School of Biomedical Sciences, University of Ulster, Coleraine, BT52 1SA (United Kingdom); Li, Yuebin; Schachar, Ronald A; Chen, Wei [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Colhoun, Liza M, E-mail: b.pierscionek@ulster.ac.uk, E-mail: weichen@uta.edu [Centre for Vision and Vascular Sciences, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Grosvenor Road, Belfast, BT12 6BA (United Kingdom)

    2010-01-22

    There are no treatments for reversing or halting cataract, a disease of the structural proteins in the eye lens, that has associations with other age-related degenerative conditions such as Alzheimer's disease. The incidence of cataract and associated conditions is increasing as the average age of the population rises. Protein folding diseases are difficult to assess in vivo as proteins and their age-related changes are assessed after extraction. Nanotechnology can be used to investigate protein changes in the intact lens as well as for a potential means of drug delivery. Nanoparticles, such as cerium oxide (CeO{sub 2}) which have antioxidant properties, may even be used as a means of treating cataract directly. Prior to use in treatments, nanoparticle genotoxicity must be tested to assess the extent of any DNA or chromosomal damage. Sister chromatid exchanges were measured and DNA damage investigated using the alkaline COMET assay on cultured human lens epithelial cells, exposed to 5 and 10 {mu}g ml{sup -1} of CeO{sub 2} nanoparticles (nanoceria). Nanoceria at these dosages did not cause any DNA damage or significant increases in the number of sister chromatid exchanges. The absence of genotoxic effects on lens cells suggests that nanoceria, in the doses and exposures tested in this study, are not deleterious to the eye lens and have the potential for use in studying structural alterations, in developing non-surgical cataract treatments and in investigating other protein folding diseases.

  6. Phakic Intraocular lens- a review

    OpenAIRE

    Cruz, Francisco Miguel

    2015-01-01

    Introduction: Intraocular refractive procedures with the implantation of a Phakic Intraocular lens have become a safe efficient and predictable alternative for treating high ametropias when the use of corneal photoablative procedures is not possible. The implantation of Phakic intraocular lens preservs the accomodative function,is a reversable refractive procedure, with minimal induction of higher order aberrations compaed with corneal photoablative procedures. Methods: An analytical review o...

  7. Ascorbate in the ocular lens

    OpenAIRE

    Mody, Vino C. Jr

    2006-01-01

    Purpose: First, we intended to establish a method for sample preparation for measurement of ascorbate in whole rat and guinea pig lenses utilizing ultrafiltration and high performance liquid chromatography with ultraviolet radiation detection. Then, we aimed to investigate whether, in the albino rat, lens ascorbate concentration depends on solid dietary intake. Finally, we investigated if, in the pigmented guinea pig, lens ascorbate concentration may be elevated with drinkin...

  8. Gravitational lens surveys with LOFAR

    CERN Document Server

    Wucknitz, O

    2008-01-01

    Deep surveys planned as a Key Science Project of LOFAR provide completely new opportunities for gravitational lens searches. For the first time do large-scale surveys reach the resolution required for a direct selection of lens candidates using morphological criteria. We briefly describe the strategies that we will use to exploit this potential. The long baselines of an international E-LOFAR are essential for this project.

  9. A course in lens design

    CERN Document Server

    Velzel, Chris

    2014-01-01

    A Course in Lens Design is an instruction in the design of image-forming optical systems. It teaches how a satisfactory design can be obtained in a straightforward way. Theory is limited to a minimum, and used to support the practical design work. The book introduces geometrical optics, optical instruments and aberrations. It gives a description of the process of lens design and of the strategies used in this process. Half of its content is devoted to the design of sixteen types of lenses, described in detail from beginning to end. This book is different from most other books on lens design because it stresses the importance of the initial phases of the design process: (paraxial) lay-out and (thin-lens) pre-design. The argument for this change of accent is that in these phases much information can be obtained about the properties of the lens to be designed. This information can be used in later phases of the design. This makes A Course in Lens Design a useful self-study book, and a suitable basis for an intro...

  10. Melatonin and Sleep-Wake Rhythms before and after Ocular Lens Replacement in Elderly Humans

    Directory of Open Access Journals (Sweden)

    Marina Giménez

    2016-02-01

    Full Text Available Light of short wavelengths has been shown to play a key role in non-image forming responses. Due to aging, the ocular lens becomes more yellow reducing the transmission of short wavelengths in the elderly. In the present study, we make use of cataract surgery to investigate the effects of a relative increase of short wavelength transmission on melatonin- and sleep-wake rhythms (N = 14. We observed, on average, a delay of the sleep-wake and the nocturnal melatonin rhythms after cataract surgery. This delay is tentatively attributed to a relatively large increase of light transmittance in the evening hours more than an increase of the already relatively high light intensities found in the daytime. The later phase that we observed after cataract surgery (clear lens as compared to the earlier phase observed before cataract (yellowish lens is in agreement with the general later phase reported in the young (clear lens population.

  11. A Situated Cognition Perspective on Literacy Discourses: Seeing More Clearly through a New Lens.

    Science.gov (United States)

    Taylor, Maurice C.; Blunt, Adrian

    2001-01-01

    Using a situated cognition framework, 24 vignettes of literacy practices were examined in 4 Canadian settings: community-based, workplace, family, and school-based literacy. Literacy researchers appear constrained by behaviorist, normative perspectives despite the shift toward humanist perspectives. (Contains 51 references.) (SK)

  12. Dose limits to the eye lens

    Energy Technology Data Exchange (ETDEWEB)

    Sion, N.

    2016-09-15

    Protecting the human body from the effects of ionizing radiation is essential to forestall stochastic effects and require placing limits on the effective dose. Dose limits on specific organs are also necessary to reduce the deterministic effects and tissue reactions. The standard for radiation protection was ISO 15382 (2002) which mainly dealt with beta radiation for nuclear power plant workers. Clearly an update is required to allow for new technology and the proliferative use of radiation in medical practices. There is a need for more explicit radiation monitoring to operators and staff. ICRP118 (International Commission on Radiological Protection), Ref. 1, evolved their recommendations to include eye lens doses as a follow on to their publication 103 and to focus on radiation exposures. It provides updated estimates of 'practical' threshold doses for tissue injury at the level of 1% incidence. This paper discusses the current status and the recommendation for a drastic reduction of the dose limit to the eye lens. (author)

  13. The 2010 IODC lens design problem: the green lens

    Science.gov (United States)

    Juergens, Richard C.

    2010-08-01

    The lens design problem for the 2010 IODC is to design a 100 mm focal length lens in which every optical surface has the same radius of curvature, positive or negative, or is plano. The lens is used monochromatically at 532 nm and is made of only Schott N-BK7 glass. The goal of the problem is to maximize the product of the semi-field of view and the entrance pupil diameter while holding the distortion to within +/-5% and the RMS wavefront error to <= 0.07 wave within the field of view. There were 37 entries from eight different countries. Four different commercial lens design programs were used, along with two custom, in-house programs. The number of lens elements in the entries ranged from 3 to 64. The overall length of the lenses varied from 105 mm to 3.6 km. The winning entry had an entrance pupil diameter of 81.3 mm and a semi-field of view of 43.5° for a merit function product of 3537.

  14. The effect of gain saturation in a gain compensated perfect lens

    CERN Document Server

    Andresen, Marte P Hatlo; Haakestad, Magnus W; Krogstad, Harald E; Skaar, Johannes

    2010-01-01

    The transmission of evanescent waves in a gain-compensated perfect lens is discussed. In particular, the impact of gain saturation is included in the analysis, and a method for calculating the fields of such nonlinear systems is developed. Gain compensation clearly improves the resolution; however, a number of nonideal effects arise as a result of gain saturation. The resolution associated with the lens is strongly dependent on the saturation constant of the active medium.

  15. Ion clearing in an ERL

    Science.gov (United States)

    Hoffstaetter, Georg H.; Liepe, Matthias

    2006-02-01

    The rest-gas in the beam-pipe of a particle accelerator is readily ionized by effects like collisions, synchrotron radiation and field emission. Positive ions are attracted to electron beams and create a nonlinear potential in the vicinity of the beam which can lead to beam halo, particle loss, optical errors or transverse and longitudinal instabilities. In an energy recovery linac (ERL) where beam-loss has to be minimal, and where beam positions and emittances have to be very stable in time, these ion effects have to be avoided. Here we investigate three measures of avoiding ion accumulation: (a) A long gap between linac bunch trains that allows ions to drift out of the beam region, a measure regularly applied in linacs; (b) a short ion clearing gap in the beam that leads to a time varying beam potential and produces large excited oscillations of ions around the electron beam, a measure regularly applied in storage rings; (c) Clearing electrodes that create a sufficient voltage to draw ions out of the beam potential, a measure used for DC electron beams and for antiproton beams. For the parameters of the X-ray ERL planned at Cornell University we show that method (a) cannot be applied, method (b) is technically cumbersome, and (c) should be most easily applicable.

  16. Pharmacognostic evaluation of Lens culinaris Medikus seeds

    Institute of Scientific and Technical Information of China (English)

    Kripi Vohra; Vivek Kumar Gupta

    2012-01-01

    Objective: To present a detailed pharmacognostic study of the Lens culinaris Medikus (Fabaceae) seeds, a food grain used as Dhal in India. Methods: The macroscopy, microscopy, fluorescence analysis of powdered drug, physicochemical analysis, preliminary testing and other WHO recommended methods for standardization were investigated. Results: Seeds are greyish brown in colour. Treatment of powdered drug with various chemical reagents showed the presence of proteins, cellulose, lignins and fixed oils. Microscopy of seeds revealed the presence of starch grains in seed. The colour of seed coat changed from brown to greenish grey in day light and brown to black at 254nm when treated with acetic acid. Total ash value of the seeds was found to be 1.86% w/w whereas foreign organic matter was found to be nil. Qualitative phytochemical analysis revealed the presence of tannins and flavonoids in acetone extract. Conclusions: The present study on pharmacognostic profile of Lens culinaris Medikus seeds provides an important tool in identification and authentication of this plant to researchers in future.

  17. Adding a lens Improves spinning speed characterization.

    Science.gov (United States)

    Mihaliuk, Eugene; Gullion, Terry

    2015-11-01

    Highly stable sample rotation is important in many solid-state NMR experiments. Whether the necessary stability is achieved is not always clear. Typically only an average frequency over some time interval (often relatively long and unknown) is available from the spinning speed controller readout, which is not representative of the short-term variations of instantaneous rotation frequency. The necessity of the relatively slow measurement of spinning speed is a consequence of phase noise in the tachometer, which prevents speed measurement to be both rapid and precise at the same time. We show that adding a lens to the tachometer, without any other changes in the probe, reduces phase noise by nearly an order of magnitude and allows improved measurement of the spinning speed.

  18. Qualification of a Null Lens Using Image-Based Phase Retrieval

    Science.gov (United States)

    Bolcar, Matthew R.; Aronstein, David L.; Hill, Peter C.; Smith, J. Scott; Zielinski, Thomas P.

    2012-01-01

    In measuring the figure error of an aspheric optic using a null lens, the wavefront contribution from the null lens must be independently and accurately characterized in order to isolate the optical performance of the aspheric optic alone. Various techniques can be used to characterize such a null lens, including interferometry, profilometry and image-based methods. Only image-based methods, such as phase retrieval, can measure the null-lens wavefront in situ - in single-pass, and at the same conjugates and in the same alignment state in which the null lens will ultimately be used - with no additional optical components. Due to the intended purpose of a Dull lens (e.g., to null a large aspheric wavefront with a near-equal-but-opposite spherical wavefront), characterizing a null-lens wavefront presents several challenges to image-based phase retrieval: Large wavefront slopes and high-dynamic-range data decrease the capture range of phase-retrieval algorithms, increase the requirements on the fidelity of the forward model of the optical system, and make it difficult to extract diagnostic information (e.g., the system F/#) from the image data. In this paper, we present a study of these effects on phase-retrieval algorithms in the context of a null lens used in component development for the Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission. Approaches for mitigation are also discussed.

  19. Lens Epithelial Cell Proliferation and Cell Density in Human Age-related Cataract

    Institute of Scientific and Technical Information of China (English)

    Xialin Liu; Yizhi Liu; Jianliang Zheng; Qiang Huang; Huling Zheng

    2000-01-01

    Purpose: To discuss the potential effect of the lens epithelial cell proliferation in age-related cataract.Methods: In vitro cell proliferation was assayed by MTT method to evaluate the lens epithelial cell density, index, and proliferation capacity in normal lens and all kinds of age-related cataract. Capsulotomy specimens from all kinds of patients who underwent cataract phacoemulsification extraction surgery were compared with the lens epithelial specimens from non-cataract lenses of Eye Bank eyes.Results: Lens epithelial cell density of central anterior capsule (LECD) in female normal lens was higher than that in male, LECD in nuclear cataract( > NⅢ ) was higher than that in normal lens, but in the mature cortical cataract, LF CD was lower. Mitotic index of three kinds of age-related cataracts in vivo had no statistical difference, neither did cell proliferation capacity of cultivated cells in vitro.Conclusion: The individual difference of lens epithelial cell density and proliferation capacity in vivo may be an important underlying cause for senile cataract in the cellular level, especially for nuclear cataract.

  20. Planar immersion lens with metasurfaces

    CERN Document Server

    Ho, John S; Tanabe, Yuji; Yeh, Alexander J; Fan, Shanhui; Poon, Ada S Y

    2015-01-01

    The solid immersion lens is a powerful optical tool that allows light entering material from air or vacuum to focus to a spot much smaller than the free-space wavelength. Conventionally, however, they rely on semispherical topographies and are non-planar and bulky, which limits their integration in many applications. Recently, there has been considerable interest in using planar structures, referred to as metasurfaces, to construct flat optical components for manipulating light in unusual ways. Here, we propose and demonstrate the concept of a planar immersion lens based on metasurfaces. The resulting planar device, when placed near an interface between air and dielectric material, can focus electromagnetic radiation incident from air to a spot in material smaller than the free-space wavelength. As an experimental demonstration, we fabricate an ultrathin and flexible microwave lens and further show that it achieves wireless energy transfer in material mimicking biological tissue.

  1. Tinting of intraocular lens implants

    Energy Technology Data Exchange (ETDEWEB)

    Zigman, S.

    1982-06-01

    Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users.

  2. International rigid contact lens prescribing.

    Science.gov (United States)

    Efron, Nathan; Morgan, Philip B; Helland, Magne; Itoi, Motozumi; Jones, Deborah; Nichols, Jason J; van der Worp, Eef; Woods, Craig A

    2010-06-01

    Rigid lenses have been fitted less since the introduction of soft lenses nearly 40 years ago. Data that we have gathered from annual contact lens fitting surveys conducted in Australia, Canada, Japan, the Netherlands, Norway, the UK and the USA between 2000 and 2008 facilitate an accurate characterization of the pattern of the decline of rigid lens fitting during the first decade of this century. There is a trend for rigid lenses to be utilized primarily for refitting those patients who are already successful rigid lens wearers-most typically older females being refit with higher Dk materials. Rigid lenses are generally fitted on a full-time basis (four or more days of wear per week) without a planned replacement schedule. Orthokeratology is especially popular in the Netherlands, but is seldom prescribed in the other countries surveyed.

  3. Algebraic Lens Distortion Model Estimation

    Directory of Open Access Journals (Sweden)

    Luis Alvarez

    2010-07-01

    Full Text Available A very important property of the usual pinhole model for camera projection is that 3D lines in the scene are projected to 2D lines. Unfortunately, wide-angle lenses (specially low-cost lenses may introduce a strong barrel distortion, which makes the usual pinhole model fail. Lens distortion models try to correct such distortion. We propose an algebraic approach to the estimation of the lens distortion parameters based on the rectification of lines in the image. Using the proposed method, the lens distortion parameters are obtained by minimizing a 4 total-degree polynomial in several variables. We perform numerical experiments using calibration patterns and real scenes to show the performance of the proposed method.

  4. Large scale water lens for solar concentration.

    Science.gov (United States)

    Mondol, A S; Vogel, B; Bastian, G

    2015-06-01

    Properties of large scale water lenses for solar concentration were investigated. These lenses were built from readily available materials, normal tap water and hyper-elastic linear low density polyethylene foil. Exposed to sunlight, the focal lengths and light intensities in the focal spot were measured and calculated. Their optical properties were modeled with a raytracing software based on the lens shape. We have achieved a good match of experimental and theoretical data by considering wavelength dependent concentration factor, absorption and focal length. The change in light concentration as a function of water volume was examined via the resulting load on the foil and the corresponding change of shape. The latter was extracted from images and modeled by a finite element simulation.

  5. Endophthalmitis following cataract extraction.

    Science.gov (United States)

    McClellan, K; Coster, D J; Badenoch, P R; Sanders, R; Chandraratnam, E; Kupa, A

    1987-02-01

    We describe a case of bacterial endophthalmitis complicating routine cataract extraction and intraocular lens implantation in a 91-year-old woman. The ocular and systemic factors that may have predisposed to intraocular infection in this case, and the possibility of predicting these pre-operatively, are discussed.

  6. Panoramic lens designed with transformation optics

    Science.gov (United States)

    Wang, Huaping; Deng, Yangyang; Zheng, Bin; Li, Rujiang; Jiang, Yuyu; Dehdashti, Shahram; Xu, Zhiwei; Chen, Hongsheng

    2017-01-01

    The panoramic lens is a special kind of lens, which is applied to observe full view. In this letter, we theoretically present a panoramic lens (PL) using transformation optics method. The lens is designed with inhomogeneous and anisotropic constitutive parameters, which has the ability to gather light from all directions and confine light within the visual angle of observer. Simulation results validate our theoretical design.

  7. SimpLens: Interactive gravitational lensing simulator

    Science.gov (United States)

    Saha, Prasenjit; Williams, Liliya L. R.

    2016-06-01

    SimpLens illustrates some of the theoretical ideas important in gravitational lensing in an interactive way. After setting parameters for elliptical mass distribution and external mass, SimpLens displays the mass profile and source position, the lens potential and image locations, and indicate the image magnifications and contours of virtual light-travel time. A lens profile can be made shallower or steeper with little change in the image positions and with only total magnification affected.

  8. MI Gap Clearing Kicker Magnet Design Review

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Chris; /Fermilab

    2008-10-01

    The kicker system requirements were originally conceived for the NOvA project. NOvA is a neutrino experiment located in Minnesota. To achieve the desired neutrino flux several upgrades are required to the accelerator complex. The Recycler will be used as a proton pre-injector for the Main Injector (MI). As the Recycler is the same size as the MI, it is possible to do a single turn fill ({approx}11 {micro}sec), minimizing the proton injection time in the MI cycle and maximizing the protons on target. The Recycler can then be filled with beam while the MI is ramping to extract beam to the target. To do this requires two new transfer lines. The existing Recycler injection line was designed for 10{pi} pbar beams, not the 20{pi} proton beams we anticipate from the Booster. The existing Recycler extraction line allows for proton injection through the MI, while we want direct injection from the Booster. These two lines will be decommissioned. The new injection line from the MI8 line into the Recycler will start at 848 and end with injection kickers at RR104. The new extraction line in the RR30 straight section will start with a new extraction kicker at RR232 and end with new MI injection kickers at MI308. Finally, to reduce beam loss activation in the enclosure, a new gap clearing kicker will be used to extract uncaptured beam created during the slip stack injection process down the existing dump line. It was suggested that the MI could benefit from this type of system immediately. This led to the early installation of the gap clearing system in the MI, followed by moving the system to Recycler during NOvA. The specifications also changed during this process. Initially the rise and fall time requirements were 38 ns and the field stability was {+-}1%. The 38 ns is based on having a gap of 2 RF buckets between injections. (There are 84 RF buckets that can be filled from the Booster for each injection, but 82 would be filled with beam. MI and Recycler contain 588 RF buckets

  9. 21 CFR 886.3600 - Intraocular lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens. 886.3600 Section 886.3600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials...

  10. In vivo human crystalline lens topography.

    Science.gov (United States)

    Ortiz, Sergio; Pérez-Merino, Pablo; Gambra, Enrique; de Castro, Alberto; Marcos, Susana

    2012-10-01

    Custom high-resolution high-speed anterior segment spectral domain optical coherence tomography (OCT) was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo. The system was provided with custom algorithms for denoising and segmentation of the images, as well as for fan (scanning) and optical (refraction) distortion correction, to provide fully quantitative images of the anterior and posterior crystalline lens surfaces. The method was tested on an artificial eye with known surfaces geometry and on a human lens in vitro, and demonstrated on three human lenses in vivo. Not correcting for distortion overestimated the anterior lens radius by 25% and the posterior lens radius by more than 65%. In vivo lens surfaces were fitted by biconicoids and Zernike polynomials after distortion correction. The anterior lens radii of curvature ranged from 10.27 to 14.14 mm, and the posterior lens radii of curvature ranged from 6.12 to 7.54 mm. Surface asphericities ranged from -0.04 to -1.96. The lens surfaces were well fitted by quadrics (with variation smaller than 2%, for 5-mm pupils), with low amounts of high order terms. Surface lens astigmatism was significant, with the anterior lens typically showing horizontal astigmatism ([Formula: see text] ranging from -11 to -1 µm) and the posterior lens showing vertical astigmatism ([Formula: see text] ranging from 6 to 10 µm).

  11. Professoren og Ålen

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2016-01-01

    Biolog og havforsker Johannes Schmidt regnes for at være Danmarks mest betydningsfulde havforsker gennem tiderne. Hans mange forskningsbaserede jordomsejlinger bragte ham til eksotiske egne og til opdagelsen af adskillige nye dyrearter. Dog blev særligt ålen og dens gydepladser et hovedfokus for ...

  12. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  13. Professoren og Ålen

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2016-01-01

    Biolog og havforsker Johannes Schmidt regnes for at være Danmarks mest betydningsfulde havforsker gennem tiderne. Hans mange forskningsbaserede jordomsejlinger bragte ham til eksotiske egne og til opdagelsen af adskillige nye dyrearter. Dog blev særligt ålen og dens gydepladser et hovedfokus...

  14. Estimation of the hybrid lens parameters through rigid gas permeable lens fitting

    OpenAIRE

    Hasani, Mohammadali; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Yekta, Abbas Ali; Dadbin, Nooshin; khabazkhoob, Mehdi

    2016-01-01

    Purpose To estimate the fitting parameters of the hybrid contact lens in patients with corneal ectasia using the rigid gas permeable (RGP) lens. Methods Thirty-four eyes with corneal ectasia were evaluated in this study. The patients were examined once with the RGP lens and once with the hybrid contact lens. The relationship between the base curvature of the RGP and the vault of the hybrid lens and the correlation between their powers were analyzed. Results We found a linear relationship betw...

  15. Improvement and application effect of water vapor moving signal extraction algorithm in “clear sky region” from FY-2 E infrared channel%FY-2 E红外通道“晴空区”水汽信息提取算法的改进与应用效果

    Institute of Scientific and Technical Information of China (English)

    赵航; 王振会; 杨璐; 詹奕哲; 汤敏

    2015-01-01

    The quadratic difference method, as an improved water vapor signal extraction algorithm, is employed in“clear sky region” from FY -2E infrared channel. By means of both split window and temporal difference calculation from infrared cloud mask images, the method can weaken the surface temperature interference and help trace the weak signal of water vapor in “clear sky region”, regardless of the order of the two calculations. Application examples show that this method can trace the weak signal of water vapor in “clear sky region” more effectively and make up for the lacking wind field data in clear sky with high water vapor content values as compared with the obvious limitation of deriving cloud motion wind by the traditional method. A comparison between the wind fields using this technique and that obtained from the NCEP reanalysis data shows a good relative accuracy.%提出了一种改进的FY-2E红外通道“晴空区”水汽信息提取算法———二次差分法,即在对红外分裂窗云掩图进行分裂窗差分的基础上再进行时间差分处理,或者先进行时间差分后再进行分裂窗差分处理。该方法能减弱晴空区地表温度变化对水汽信息提取的干扰,从而有助于获得水汽团的纹理及其移动信息。实验结果表明,应用该方法可以更加有效地追踪红外通道“晴空区”水汽微弱示踪信号的移动,获得传统云导风方法所无法得到的晴空水汽含量高值区风场信息,且晴空风矢与NCEP( national centers for environmental prediction)再分析资料级低空风场有着很好的一致性。

  16. Lens stem cells may reside outside the lens capsule: an hypothesis

    Directory of Open Access Journals (Sweden)

    Meyer Rita A

    2007-06-01

    Full Text Available Abstract In this paper, we consider the ocular lens in the context of contemporary developments in biological ideas. We attempt to reconcile lens biology with stem cell concepts and a dearth of lens tumors. Historically, the lens has been viewed as a closed system, in which cells at the periphery of the lens epithelium differentiate into fiber cells. Theoretical considerations led us to question whether the intracapsular lens is indeed self-contained. Since stem cells generate tumors and the lens does not naturally develop tumors, we reasoned that lens stem cells may not be present within the capsule. We hypothesize that lens stem cells reside outside the lens capsule, in the nearby ciliary body. Our ideas challenge the existing lens biology paradigm. We begin our discussion with lens background information, in order to describe our lens stem cell hypothesis in the context of published data. Then we present the ciliary body as a possible source for lens stem cells, and conclude by comparing the ocular lens with the corneal epithelium.

  17. Modern lens antennas for communications engineering

    CERN Document Server

    Thornton, John

    2012-01-01

    The aim of this book is to present the modern design principles and analysis of lens antennas. It gives graduates and RF/Microwave professionals the design insights in order to make full use of lens antennas.  Why do we want to write a book in lens antennas? Because this topic has not been thoroughly publicized, its importance is underestimated. As antennas play a key role in communication systems, recent development in wireless communications would indeed benefit from the characteristics of lens antennas: low profile, and low cost etc.  The major advantages of lens antennas are na

  18. Modified Scleral Flap Incision to Reduce Corneal Astigmatisn after Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    YizhiLiu; ShaozhenLi

    1995-01-01

    Purpose:To investigate a simple method during extracapsular cataract extraction with posteior chamber intraocular lens implantation in order to reduce surgically induced corneal astig-matism.Methods:A modified scleral flap incision was used in the extracapsular cataract extraction with intraocular lens implantation and the postoperative changes in conreal astigmatism was observed.Results:The peak value of postoperative corneal astigmatism was3.60D,and the corneal astigmatism regression was 2.11D,surgically induced astigmatism was less significant in modified scleral flap incision group than that in convention-al limbal incison group(P<0.05).Conclusions:The modified scleral flap inciston is an ideal incision for cataract ex-traction with intraocular lens implantation when phacoemulsifier is not avaliable.Eye Science1995;11:136-139.

  19. Conjunctival impression cytology in contact lens wearers.

    Directory of Open Access Journals (Sweden)

    Simon Priya

    2002-01-01

    Full Text Available PURPOSE: To evaluate the cytological changes in conjunctiva following regular contact lens wear and to determine the correlation, if any, between severity of cytological alteration and symptoms related to contact lens wear. METHODS: One hundred eyes (50 normal asymptomatic subjects who served as a control group were studied by conjunctival impression cytology (CIC. These subjects were fitted with rigid gas permeable (RGP or soft contact lenses and were followed up at the end of 3 and 6 months. At each follow-up visit the CIC was repeated. A filter paper with the impression specimen was stained with periodic acid schiff (PAS and haematoxylin stain to study goblet cell loss. Papanicolaou stain was done to study squamous metaplasia. The cytological changes were graded using the system described by Natadisastra et al. RESULTS: Severity of cytological changes increased with the duration of contact lens wear (P = 0.00001. At the end of 6 months, 60% of symptomatic eyes wearing soft contact lens and RGP lens showed abnormal CIC changes. None of the asymptomatic RGP contact lens wearing eyes showed abnormal CIC changes whereas 33.4% of the asymptomatic soft contact lens wearing eyes showed abnormal CIC changes (P = 0.033. Epithelial changes occurred within 3-6 months of contact lens fitting. CONCLUSION: Severity of cytological changes increased with duration of lens wear (P = 0.00001. Prevalence and severity of cytological alteration is more in symptomatic contact lens wearers. Soft contact lens wearers although asymptomatic showed severe CIC changes.

  20. Improvement in the field of binocular single vision following bilateral phacoemulsification with toric intraocular lens implantation in a patient with a partial third nerve palsy.

    Science.gov (United States)

    Subash, Malavika; Sloper, John J; Wilkins, Mark R

    2010-12-01

    A 44-year-old female teacher with partial third (oculomotor) nerve palsy had a small central field of binocular single vision (BSV) following three strabismus procedures. Over several years her field of BSV constricted further, coincident with the development of myopia in one eye secondary to early lens change and in the presence of significant astigmatism. Following bilateral lens extraction with toric intraocular lens implants, her field of BSV reexpanded.

  1. The Experimental Study on Implantation of Intraocular Lens in Different Animals

    Institute of Scientific and Technical Information of China (English)

    WANGGui-qin; PENGXiu-jun; GUHan-qing

    2004-01-01

    To prevent the complications in cataract surgeries, the eyes of rabbits and monkeys were implanted with intraocular lens for 360 days. Methods: The eyes of the rabbits were performed with phacoemulsification and soft intraocular lens implantation. The eyes of the monkeys were performed with extracapsular cataract extraction and hard intraocular lens implantation. Results: The postoperative reactions included corneal edema, anterior chamber exudation, posterior capsule opacification and so on. The complications in the eyes of the rabbits were more than that in the eyes of the monkeys. Conclusion: The different postoperative reactions happened in different animals. In clinical the choice of the operative method and intraocular lens depended on the case in order to acquire the best sight.

  2. γ-Crystallins of the chicken lens: remnants of an ancient vertebrate gene family in birds.

    Science.gov (United States)

    Chen, Yingwei; Sagar, Vatsala; Len, Hoay-Shuen; Peterson, Katherine; Fan, Jianguo; Mishra, Sanghamitra; McMurtry, John; Wilmarth, Phillip A; David, Larry L; Wistow, Graeme

    2016-04-01

    γ-Crystallins, abundant proteins of vertebrate lenses, were thought to be absent from birds. However, bird genomes contain well-conserved genes for γS- and γN-crystallins. Although expressed sequence tag analysis of chicken eye found no transcripts for these genes, RT-PCR detected spliced transcripts for both genes in chicken lens, with lower levels in cornea and retina/retinal pigment epithelium. The level of mRNA for γS in chicken lens was relatively very low even though the chicken crygs gene promoter had lens-preferred activity similar to that of mouse. Chicken γS was detected by a peptide antibody in lens, but not in other ocular tissues. Low levels of γS and γN proteins were detected in chicken lens by shotgun mass spectroscopy. Water-soluble and water-insoluble lens fractions were analyzed and 1934 proteins (chicken lens proteome 30-fold. Although chicken γS is well conserved in protein sequence, it has one notable difference in leucine 16, replacing a surface glutamine conserved in other γ-crystallins, possibly affecting solubility. However, L16 and engineered Q16 versions were both highly soluble and had indistinguishable circular dichroism, tryptophan fluorescence and heat stability (melting temperature Tm ~ 65 °C) profiles. L16 has been present in birds for over 100 million years and may have been adopted for a specific protein interaction in the bird lens. However, evolution has clearly reduced or eliminated expression of ancestral γ-crystallins in bird lenses. The conservation of genes for γS- and γN-crystallins suggests they may have been preserved for reasons unrelated to the bulk properties of the lens.

  3. Study on Titanium Nitride Film Modified for Intraocular Lens

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective:To study the characteristics of the intraocular lens using ion beam sputtering depositing titanium nitride thin film on the intraocular lens(IOLs).Methods:To deposite titanium nitride thin film on the top of intraocular lens by ion beam sputtering depositing.We analyzed the surface morphology of intraocular lens through SEM and AFM.We detected intraocular lens resolution through the measurement of intraocular lens.Biocompatibility of intraocular lens is preliminary evaluated in this test.Results:T...

  4. Lens Coupled Quantum Cascade Laser

    Science.gov (United States)

    Hu, Qing (Inventor); Lee, Alan Wei Min (Inventor)

    2013-01-01

    Terahertz quantum cascade (QC) devices are disclosed that can operate, e.g., in a range of about 1 THz to about 10 THz. In some embodiments, QC lasers are disclosed in which an optical element (e.g., a lens) is coupled to an output facet of the laser's active region to enhance coupling of the lasing radiation from the active region to an external environment. In other embodiments, terahertz amplifier and tunable terahertz QC lasers are disclosed.

  5. Fresnel Lens with Embedded Vortices

    Directory of Open Access Journals (Sweden)

    Sunil Vyas

    2012-01-01

    Full Text Available Vortices of different charges are embedded in a wavefront that has quadratic phase variation, and the intensity distribution near the focal plane is studied. This method may be useful in realizing complicated beam profiles. We have experimentally demonstrated the generation of vortex arrays having integer as well as fractional topological charges that produce different intensity profiles at the focal plane. The phase variation realized on a spatial light modulator (SLM acts as a Fresnel lens with embedded vortices.

  6. 非洲贫困地区小切口白内障囊外摘出联合人工晶状体植入术的临床分析%Clinical analysis of small incision extracapsular cataract extraction and intraocular lens implantation in poverty-stricken areas in Africa

    Institute of Scientific and Technical Information of China (English)

    唐建明

    2012-01-01

    Objective To investigate the small incision extracapsular cataract extraction and intraocular lens implantation in the clinical effect and feasibility of poverty-stricken areas of Africa.Methods During the foreign aid in Moroccan from march 2009 to march 2011,the age of 45 to 86-year-old Moroccan patients with 538 cases (580 eyes) had undergone small incision extracapsular cataract extraction and intraocular lens implantation.The visual acuity,postoperative complications were observed.Results Visual acuity of1.0 or more were obtained in 25 eyes (4.31%),0.6~1.0in 148 eyes (25.52%),0.3 ~0.5 in 328 eyes (56.55%),0.05 ~0.25 in 74 eyes (12.76%),<0.05 in 5 eyes (0.86%).Literacy rate was 99.14%,removing residual was 86.38%.Intraoperative complications:iris prolapse 23 eyes (3.97%) ; posterior capsular rupture 33 eyes (5.69%),among which 28 eyes were applied posterior chamber intraocular lens implantation at stage Ⅰ,two cases at stage Ⅱ,the other three eases gave up implantation.Postoperative complications:corneal edema,opacity 21 eyes (3.62%),no corneal bullae or corneal decompensation occurred.Anterior chamber inflammatory response 51 eyes (8.79%).Late-onset uveitis 11 eyes,of which 9 related to diabetes.All patients were found no retinal detachment,secondary glaucoma,intraocular lens dislocation or endophthalmitis.Conclusion Small incision extracapsular cataract extraction with IOL implantation in the joint damage,quick recovery,easy to operate,low cost,suitable for the hospital,poor economic conditions,the places and people,it become possible to make the local poor people cataract bright.%目的 探讨在援非工作过程中进行小切口白内障囊外摘出联合人工晶状体植入术的手术效果与可行性.方法 2009年3月至2011年3月作者在援非期间对年龄45 ~ 86岁的摩洛哥患者538人(580眼)进行小切口白内障囊外摘出联合人工晶状体植入术,并对术后视力、术后并发症的

  7. Avaliação da eficácia da facectomia com implante de lente intra-ocular na infância Efficacy of pediatric cataract extraction with intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Núbia Cristina de Freitas Maia

    2005-12-01

    . METHODS: A total of 33 eyes in 27 children were studied. Children with either unilateral or bilateral cataracts were submitted to lensectomy surgery via pars plana, with intraocular lens implant, associated with primary posterior capsulectomy and anterior vitrectomy. The intraocular lenses were calculated for emmetropia in the first postoperative month. All children were less than six years old at the time of the surgery and had a 2.9 year average follow-up. They were divided into 3 groups. Group I (10 eyes, children with unilateral cataracts and under three years old at the time of the surgery; group II (11 eyes, children with unilateral cataracts and above three years old; group III (12 eyes, children with bilateral cataracts and above three years old at the time of the surgery. RESULTS: On the last follow-up examination recorded visual acuity was equal to or above 20/40 in 85% of the eyes. A spherical equivalent close to emmetropia in the first postoperative month was obtained in 70% of the children of group III but only in 30% of group I. Regarding postoperative refraction variation, myopic shift was detected in 81.81% of the cases. The younger the children were when undergoing surgery, the greater the refractional alteration. CONCLUSION: Despite the myopic shift that happens with the use of intraocular lenses in the treatment of pediatric aphakia in children under six years old, the visual result is very good and the residual refraction correction is easily performed. A more prolonged postoperative follow-up would be necessary for long-term evaluation of the results.

  8. 五倍子水提取物清除牙科综合治疗椅水路生物膜的效果%The clearing effect of Chinese gallnut water extract on the biofilms in dental unit water lines

    Institute of Scientific and Technical Information of China (English)

    俞雪芬; 李聪; 王欣芝; 胡国庆

    2012-01-01

    Objective To evaluate the clearing effect of different concentration Chinese Gallnut water extract on the biofilms in dental unit water lines. Methods The dental unit water lines were divided into two groups. The biofilms in the two groups were cleared by different concentration Chinese Gallnut water extract (lOOmg/ml vs. 62.5mg/ml) for four weeks. The formation of biofilms were observed through laser confocal microscopy after they were dyed by fluorescent yellow at the first,second, third and fourth week after intervention. At the same time,the samples were collected in the cooling water for bacteria culture. Results Before intervention, there was no significant difference in the fluorescent intensity or the bacteria colonies in the cooling water between the two groups(P>0.05). After intervention,there were significant differences in the above index between the two groups (P<0.05). There was positive correlation between the bacteria colonies and the fluorescent intensity. Conclusion Chinese Gallnut water extract can effectively remove the biofilm. The removal efficiency is proportional to the concentration and time.%目的 评价不同浓度五倍子水提取物对牙科综合治疗椅水路生物膜的清除作用.方法 根据干预所用的五倍子水提取物浓度分为A组与B组,两组在实验起始点形成相同的生物膜后进行干预.每天治疗结束后,A组将浓度为100mg/ml的五倍子水提取物、B组将浓度为62.5mg/ml的五倍子水提取物,分别抽吸入综合治疗椅水道内,并保留至次晨,连续使用4周.分别于干预前及干预后1、2、3、4周时采样,荧光黄染色后激光共聚焦电镜观察生物膜的形成情况,照片进行定量分析,同时采集手机冷却水培养计数细菌菌落数.结果 生物膜荧光强度及细菌生长菌落数干预前两组比较,差异均无统计学意义(P>0.05);干预后同组不同时间点比较,差异均有统计学意义(P<0.05),组间比

  9. Commercially available rigid gas-permeable contact lens for protecting the cornea from drying during vitrectomy with a wide viewing system

    Directory of Open Access Journals (Sweden)

    Kamei M

    2012-08-01

    Full Text Available Motohiro Kamei, Nagakazu Matsumura, Hirokazu Sakaguchi, Yusuke Oshima, Yasushi Ikuno, Kohji NishidaDepartment of Ophthalmology, Osaka University Graduate School of Medicine, Osaka, JapanPurpose: We evaluated the usefulness of commercially available materials for protecting the cornea from drying during vitrectomy with a wide-angle viewing system.Methods: Three vitreoretinal surgeons evaluated fundus visibility during vitrectomy on the images of five study materials used on the cornea: balanced saline solution, a viscoelastic agent, a vitrectomy contact lens, a rigid gas permeable (RGP contact lens, and a soft contact lens. Fundus visibility was graded using the following scale: grade 1, unclear; grade 2, slightly unclear; grade 3, clear; and grade 4, very clear.Results: Respective scores for each material used during core vitrectomy and membrane removal were: balanced saline solution, 3.3/3.3; viscoelastic agent, 3.8/3.3; vitrectomy contact lens, 3.3/4.0; RGP contact lens, 4.0/3.9; soft contact lens, 1.1/not applicable.Conclusion: The RGP contact lens provided visibility similar to or clearer than that obtained with other methods. Because of its ease of use and lower cost, use of the RGP contact lens is ideal during vitrectomy performed with a wide-angle viewing system.Keywords: contact lens, RGP, viscoelastic agent, vitrectomy, wide viewing system

  10. Evolution of a pre and post lens tear film with a contact lens

    Science.gov (United States)

    Gerhart, Matthew; Anderson, Daniel

    2012-11-01

    The work is the development, implementation, and analysis of a two-dimensional tear film model including a porous contact lens. The geometry of the problem is: a pre-lens layer that is a thin tear film between the outside air and contact lens, a contact lens that is a rigid but movable porous substrate, and a post-lens layer that is a thin film layer between the contact lens and the cornea. We are looking at short and long term behavior of the evolution of the thin film in the pre-lens layer coupled with the porous layer and the thin squeeze film in the post-lens layer. We model the different behaviors that arise as the Darcy number, evaporation effects, and boundary flux conditions change.

  11. Lateral shear interferometry with holo shear lens

    Science.gov (United States)

    Joenathan, C.; Mohanty, R. K.; Sirohi, R. S.

    1984-12-01

    A simple method for obtaining lateral shear using holo shear lenses (HSL) has been discussed. This simple device which produces lateral shears in the orthogonal directions has been used for lens testing. The holo shear lens is placed at or near the focus of the lens to be tested. It has also been shown that HSL can be used in speckle shear interferometry as it performs both the functions of shearing and imaging.

  12. An inverse and analytic lens design method

    OpenAIRE

    Lu, Yang; Lakshminarayanan, Vasudevan

    2016-01-01

    Traditional lens design is a numerical and forward process based on ray tracing and aberration theory. This method has limitations because the initial configuration of the lens has to be specified and the aberrations of the lenses have to considered. This paper is an initial attempt to investigate an analytic and inverse lens design method, called Lagrange, to overcome these barriers. Lagrange method tries to build differential equations in terms of the system parameters and the system input ...

  13. 17 CFR 39.4 - Procedures for implementing derivatives clearing organization rules and clearing new products.

    Science.gov (United States)

    2010-04-01

    ... derivatives clearing organization rules and clearing new products. 39.4 Section 39.4 Commodity and Securities... implementing derivatives clearing organization rules and clearing new products. (a) Request for approval of... of § 40.6 of this chapter. (c) Acceptance of new products for clearing. (1) A dormant...

  14. Coculture with intraocular lens material-activated macrophages induces an inflammatory phenotype in lens epithelial cells.

    Science.gov (United States)

    Pintwala, Robert; Postnikoff, Cameron; Molladavoodi, Sara; Gorbet, Maud

    2015-03-01

    Cataracts are the leading cause of blindness worldwide, requiring surgical implantation of an intraocular lens. Despite evidence of leukocyte ingress into the postoperative lens, few studies have investigated the leukocyte response to intraocular lens materials. A novel coculture model was developed to examine macrophage activation by hydrophilic acrylic (poly(2-hydroxyethyl methacrylate)) and hydrophobic acrylic (polymethylmethacrylate) commercial intraocular lens. The human monocytic cell line THP-1 was differentiated into macrophages and cocultured with human lens epithelial cell line (HLE-B3) with or without an intraocular lens for one, two, four, or six days. Using flow cytometry and confocal microscopy, expression of the macrophage activation marker CD54 (intercellular adhesion molecule-1) and production of reactive oxygen species via the fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate were examined in macrophages. α-Smooth muscle actin, a transdifferentiation marker, was characterized in lens epithelial cells. The poly(2-hydroxyethyl methacrylate) intraocular lens prevented adhesion but induced significant macrophage activation (p intraocular lens), while the polymethylmethacrylate intraocular lens enabled adhesion and multinucleated fusion, but induced no significant activation. Coculture with either intraocular lens increased reactive oxygen species production in macrophages after one day (p intraocular lens, with hydrophilic surfaces inducing higher activation than hydrophobic surfaces. These findings provide a new method of inquiry into uveal biocompatibility, specifically through the quantification of cell-surface markers of leukocyte activation.

  15. Paediatric intraocular lens implants: accuracy of lens power calculations.

    Science.gov (United States)

    O'Gallagher, M K; Lagan, M A; Mulholland, C P; Parker, M; McGinnity, G; McLoone, E M

    2016-09-01

    PurposeThis study aims to evaluate the accuracy of lens prediction formulae on a paediatric population.MethodsA retrospective case-note review was undertaken of patients under 8 years old who underwent cataract surgery with primary lens implantation in a regional referral centre for paediatric ophthalmology, excluding those whose procedure was secondary to trauma. Biometric and refractive data were analysed for 43 eyes, including prediction errors (PE). Statistical measures used included mean absolute error (MAE), median absolute error (MedAE), Student's t-test and Lin's correlation coefficient.ResultsThe mean PE using the SRK-II formula was +0.96 D (range -2.47D to +2.41 D, SD 1.33 D, MAE 1.38 D, MedAE 1.55, n=15). The mean PE was smaller using SRK/T (-0.18 D, range -3.25 D to +3.95 D, SD 1.70 D, MAE 1.30 D, MedAE 1.24, n=27). We performed an analysis of the biometry data using four different formula (Hoffer Q, Holladay 1, SRK-II and SRK/T). Hoffer Q showed a smaller MedAE than other formulae but also a myopic bias.ConclusionOur clinical data suggest SRK/T was more accurate in predicting post-operative refraction in this cohort of paediatric patients undergoing cataract surgery. Hoffer Q may have improved accuracy further.

  16. Flat lens for seismic waves

    CERN Document Server

    Brule, Stephane; Guenneau, Sebastien

    2016-01-01

    A prerequisite for achieving seismic invisibility is to demonstrate the ability of civil engineers to control seismic waves with artificially structured soils. We carry out large-scale field tests with a structured soil made of a grid consisting of cylindrical and vertical holes in the ground and a low frequency artificial source (< 10 Hz). This allows the identification of a distribution of energy inside the grid, which can be interpreted as the consequence of an effective negative refraction index. Such a flat lens reminiscent of what Veselago and Pendry envisioned for light opens avenues in seismic metamaterials to counteract the most devastating components of seismic signals.

  17. Intraocular lens with accommodation capacity

    OpenAIRE

    Dorronsoro, Carlos; Alejandre, Nicolás; Bekesi, Nandor; Marcos, Susana

    2014-01-01

    Intraocular lens with accommodation capacity comprising a first optical member (1) having a dynamic optical power, to which a second optical member (2) with a fixed optical power is affixed, in such a manner that at least a central part of each of one of one of the curved surfaces (2a, 2b) of the second optical member (2) and of at least one of the surfaces (1a, 1b) of the first optical member (1) are in contact with each other, the second optical member (2) and the first optical member (1) p...

  18. Atom lens without chromatic aberrations

    CERN Document Server

    Efremov, Maxim A; Schleich, Wolfgang P

    2012-01-01

    We propose a lens for atoms with reduced chromatic aberrations and calculate its focal length and spot size. In our scheme a two-level atom interacts with a near-resonant standing light wave formed by two running waves of slightly different wave vectors, and a far-detuned running wave propagating perpendicular to the standing wave. We show that within the Raman-Nath approximation and for an adiabatically slow atom-light interaction, the phase acquired by the atom is independent of the incident atomic velocity.

  19. Controversies in intraocular lens implantation in pediatric uveitis.

    Science.gov (United States)

    Phatak, Sumita; Lowder, Careen; Pavesio, Carlos

    2016-12-01

    Cataract is one of the most common and visually debilitating complications of pediatric uveitis. It develops as a consequence of chronic inflammation and steroid use and is seen most often in juvenile idiopathic arthritis (JIA)-associated uveitis. Cataract extraction with intraocular lens (IOL) insertion has been carried out with a measure of success in non-uveitic pediatric eyes, but in cases of uveitis, multiple factors affect the final outcome. Chronic inflammation and its sequelae such as band keratopathy, posterior synechiae, and cyclitic membranes make surgical intervention more challenging and outcome less certain. Postoperative complications like increased inflammation, glaucoma, posterior capsular opacification, retrolental membranes, and hypotony may compromise the visual outcome. Early refractive correction is imperative in pediatric eyes to prevent amblyopia. The use of contact lenses and intraocular lenses in pediatric uveitic eyes were fraught with complications in the past. Surgical interventions such as vitreo-lensectomy followed by contact lens fitting and small incision cataract surgery followed by different types of intraocular lenses have been utilized, and many reports have been published, albeit in small patient groups. This review analyzes and discusses the existing literature on intraocular lens implantation in cases of pediatric uveitic cataract surgery.

  20. The influence of lens extraction on the outcomes of vireoretinal surgery for diabetic retinopathy%晶状体摘除对糖尿病视网膜病变玻璃体视网膜手术效果的影响

    Institute of Scientific and Technical Information of China (English)

    王娟; 陈松; 张珑俐; 赵秉水; 李燕

    2008-01-01

    Objective To investigate outcomes of lens extraction during the vireoretinai surgery (VRS)for diabetic retinopathy.Methods 80 eyes from 68 cases of diabetic retinopathy accepted VRS from February 2001 to August 2007.The eyes remained phakic after VRS were compared with the eyes that were either aphakic or pseudophakic (nonphakic)postoperatively.The average follow-up time was (12.24±9.13). months.Results Visual acuity kept stable or improved in 87.3% of the phakic eyes and 72% of the nonphakic eyes (x2=4.191 ,P=0.062).The reattachment rate are 92.73% and 96% in the phakic and nonphakic groups separately (x2=0.314,P=1.000).Rubeosis iridis developed in 2 phakic eyes and two nonphakic in the phakic and nonphakic groups (x2=4.513, P=0.095).The rates of fibrous exudation of anterior chamber and macular edema were higher in nonphakic group than in phakic group(P<0.05).Conclusions Lens extraction does not influence the outcomes of diabetic 1 vitreoretinal surgery, and there are no significant difference in vitreoretinal reoperation rate and the outcomes of anatomy and visual acuity between the two groups.%目的 探讨晶状体摘除对糖尿病视网膜病变(diabetic retinopathy,DR)玻璃体视网膜手术(vitreoretinal surgery,VRS)效果的影响.方法 回顾性分析2001年2月至2007年8月行VRS的68例(80只眼),比较摘除晶状体眼同人工晶状体眼与保留晶状体眼的手术效果,随访5~63个月,平均(12.24±9.13)月.结果 术后87.27%的保留晶状体眼及68%的摘除晶状体眼视力提高或不变(x2=4.191,P=0.062);再次VRS率在保留晶状体组为12.7%,摘除晶状体组20%(x2=0.713.P=0.502);解剖复位率在保留和摘除晶状体眼分别为92.73%和96%(x2=0.314,P=1.000);保留晶状体组和摘除晶状体组各2只眼发生虹膜红变(x2=689,P=0.585),差异均无统计学意义.术后摘除晶状体组前房纤维素性渗出和黄斑水肿的发生率较保留晶状体组增加,差异有统计学意义(P<0.05).结论 晶状体

  1. 糖尿病合并白内障人工晶状体植入术后眼内炎的临床及预后分析%The clinical and prognosis of endophthalmitis of diabetes complicated with cataract extraction and intraocular lens implantation after operation

    Institute of Scientific and Technical Information of China (English)

    柴建廷; 段笃文; 王秀芳

    2014-01-01

    目的:探讨糖尿病合并白内障人工晶状体植入术后眼内炎的临床及预后。方法对我院眼科2008年1月-2013年5月收治的糖尿病合并白内障人工晶状体植入术后眼内炎6例进行临床分析。结果6例均行细菌培养+药敏试验,给予局部+全身抗感染治疗,4例行玻璃体切割+球内注药。术后1周视力:1例0.5,1例0.2,2例0.1,2例数指/20 cm。结论糖尿病合并白内障术后眼内炎患者的视力预后不良,对此类患者必须注重围术期的预防。%Objective To investigate the clinical and prognosis of endophthalmitis of diabetes complicated with cataract extraction and intraocular lens implantation after operation. Methods 6 patients with endophthalmitis were analyzed. Results Bacterial culture and drug sensitive test were made in 6 cases,and giving local and systemic anti infection thraphy.4 cases were treated with vitrectomy and ball injection.visual acuity of a week after operation (1 case 0.5;1 case 0.2;2 cases 0.1;2 cases/20cm).Conclusion The prognosis of diabetes complicated with cataract were bad,prevention must were made in peri-operation for such patients.

  2. Contact lens intolerance: refitting with dual axis lens for corneal refractive therapy

    Science.gov (United States)

    López-López, María; Pelegrín-Sánchez, José Miguel; Sobrado-Calvo, Paloma; García-Ayuso, Diego

    2011-01-01

    Corneal refractive therapy is a non-surgical procedure whose main purpose is to improve uncorrected visual acuity during the day, without spectacles or contact lenses. We report an adult woman who shows contact lens intolerance and does not want to wear eyeglasses. We used dual axis contact lens to improve lens centration. We demonstrate a maintained unaided visual acuity during one year of treatment. In conclusion, we can consider refitting with dual axis lens for corneal refractive therapy as a non-surgical option for patients who show contact lens intolerance.

  3. Fabricating customized hydrogel contact lens

    Science.gov (United States)

    Childs, Andre; Li, Hao; Lewittes, Daniella M.; Dong, Biqin; Liu, Wenzhong; Shu, Xiao; Sun, Cheng; Zhang, Hao F.

    2016-10-01

    Contact lenses are increasingly used in laboratories for in vivo animal retinal imaging and pre-clinical studies. The lens shapes often need modification to optimally fit corneas of individual test subjects. However, the choices from commercially available contact lenses are rather limited. Here, we report a flexible method to fabricate customized hydrogel contact lenses. We showed that the fabricated hydrogel is highly transparent, with refractive indices ranging from 1.42 to 1.45 in the spectra range from 400 nm to 800 nm. The Young’s modulus (1.47 MPa) and hydrophobicity (with a sessile drop contact angle of 40.5°) have also been characterized experimentally. Retinal imaging using optical coherence tomography in rats wearing our customized contact lenses has the quality comparable to the control case without the contact lens. Our method could significantly reduce the cost and the lead time for fabricating soft contact lenses with customized shapes, and benefit the laboratorial-used contact lenses in pre-clinical studies.

  4. Surgical outcomes of retinal detachment after phacoemulsification cataract extraction and intraocular lens implantation%超声乳化白内障吸除联合人工晶状体植入手术后视网膜脱离的手术效果

    Institute of Scientific and Technical Information of China (English)

    苗培建; 郑钦象; 吴荣瀚; 郑景伟; 徐明; 李文生

    2012-01-01

    目的 观察超声乳化白内障吸除联合人工晶状体(IOL)植入手术后视网膜脱离(RD)的手术效果.方法 回顾分析超声乳化白内障吸除联合IOL植入手术后发生RD并接受手术治疗的38例患者的临床资料.所有患者手术前常规行视力、裂隙灯显微镜、直接或间接检眼镜、A或B型超声、光相干断层扫描检查确诊.男性21例21只眼,女性17例18只眼.年龄42~83岁,平均年龄(57.4±11.2)岁.9例10只眼合并单纯黄斑裂孔性RD(MHRD).根据RD范围、裂孔位置及大小、增生性玻璃体视网膜病变分级等采取玻璃体切割手术或巩膜环扎手术或玻璃体切割联合巩膜环扎手术;MHRD患眼采用后巩膜加固手术.手术后随访3~26个月,平均随访时间(11.9±6.8)个月.结果 36只眼1次手术后视网膜复位成功,成功率为92.3%.2只眼手术后RD复发并放弃手术;1只眼经3次手术后成功复位.超声乳化白内障吸除联合IOL植入手术后视力和RD手术后末次随访视力对比,视力下降36只眼,占92.3%;不变1只眼,占2.6%;提高2只眼,占5.1%00.结论 超声乳化白内障吸除联合IOL植入手术后RD一次手术复位率高,但视力预后不佳.%Objective To observe surgical outcomes and influencing factors of retinal detachment (RD) after phacoemulsification cataract extraction and intraocular lens (IOL) implantation.Methods The clinical data of 38 patients who underwent retinal detachment after phacoemulsification cataract extraction and intraocular lens implantation were retrospectively analyzed.All patients diagnosed via visual acuity,slitlamp microscopy,direct or indirect ophthalmoscopy,A or B-scan ultrasonography and optical coherence tomography (OCT).There were 21 males (21 eyes) and 17 female (18 eyes).The age was from 42 to 83 years,with the mean of (57.4±11.2) years.There were nine patients (10 eyes) with simple macular hole RD (MHRD).Vitrectomy or scleral buckling or combined vitreetomy

  5. Managing as designing with a positive lens

    NARCIS (Netherlands)

    Avital, M.; Boland, R.J.; Avital, M.; Boland, R.J.; Cooperrider, D.L.

    2007-01-01

    The role and potential contribution of a positive lens to the design of systems and organizations is the focus of this essay. The positive lens refers to an emerging perspective in the social sciences that emphasizes a positive stance toward our capacity to construct better organizations and technol

  6. Liquid lens using acoustic radiation force.

    Science.gov (United States)

    Koyama, Daisuke; Isago, Ryoichi; Nakamura, Kentaro

    2011-03-01

    A liquid lens is proposed that uses acoustic radiation force with no mechanical moving parts. It consists of a cylindrical acrylic cell filled with two immiscible liquids (degassed water and silicone oil) and a concave ultrasound transducer. The focal point of the transducer is located on the oil-water interface, which functions as a lens. The acoustic radiation force is generated when there is a difference in the acoustic energy densities of different media. An acoustic standing wave was generated in the axial direction of the lens and the variation of the shape of the oil-water interface was observed by optical coherence tomography (OCT). The lens profile can be rapidly changed by varying the acoustic radiation force from the transducer. The kinematic viscosity of silicone oil was optimized to minimize the response times of the lens. Response times of 40 and 80 ms when switching ultrasonic radiation on and off were obtained with a kinematic viscosity of 200 cSt. The path of a laser beam transmitted through the lens was calculated by ray-tracing simulations based on the experimental results obtained by OCT. The transmitted laser beam could be focused by applying an input voltage. The liquid lens could be operated as a variable-focus lens by varying the input voltage.

  7. Plasma Lens for Muon and Neutrino Beams

    Energy Technology Data Exchange (ETDEWEB)

    Kahn,S.A.; Korenev, S.; Bishai, M.; Diwan, M.; Gallardo, J.C.; Hershcovitch, A.; Johnson, B.M.

    2008-06-23

    The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-energy lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma for optimum focusing. The plasma lens is immersed in an additional solenoid magnetic field to facilitate the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. Plasma lenses have the additional advantage of negligible pion absorption and scattering by the lens material and reduced neutrino contamination during anti-neutrino running. Results of particle simulations using plasma lens will be presented.

  8. Metasurface lens: Shrinking the camera size

    Science.gov (United States)

    Sun, Cheng

    2017-01-01

    A miniaturized camera has been developed by integrating a planar metasurface lens doublet with a CMOS image sensor. The metasurface lens doublet corrects the monochromatic aberration and thus delivers nearly diffraction-limited image quality over a wide field of view.

  9. Application of Q-type aspheric surface in the design of Wynne-Dyson projection lens

    Science.gov (United States)

    Ho, Cheng-Fang; Peng, Wei-Jei; Hsu, Wei-Yao

    2016-10-01

    -fit-sphere in 205 mm clear aperture, that can be tested by subaperture stitching interferometer system (ASI). The alignment tolerance of lens in decenter and tilt can be controlled in the range of ±30 micron and 20 arc-second, respectively.

  10. Intelligibility of Clear Speech: Effect of Instruction

    Science.gov (United States)

    Lam, Jennifer; Tjaden, Kris

    2013-01-01

    Purpose: The authors investigated how clear speech instructions influence sentence intelligibility. Method: Twelve speakers produced sentences in habitual, clear, hearing impaired, and overenunciate conditions. Stimuli were amplitude normalized and mixed with multitalker babble for orthographic transcription by 40 listeners. The main analysis…

  11. Unusual clear cell variant of epithelioid mesothelioma.

    Science.gov (United States)

    Dessy, E; Falleni, M; Braidotti, P; Del Curto, B; Panigalli, T; Pietra, G G

    2001-12-01

    Clear cell mesothelioma is an extremely rare neoplasm of the pleura, which can easily be mistaken for a metastasis of clear cell carcinoma to the pleura. We report here the histochemical, immunohistochemical, and ultrastructural aspects of a new case of clear cell pleural mesothelioma in a 52-year-old man with no known asbestos exposure. He was admitted to the hospital for recurrent pleural effusion, which was negative for neoplastic cells at the cytologic examination. A partial decortication of the right pleura was performed. The morphologic, immunohistochemical, and ultrastructural features reported for this case are consistent with the diagnosis of clear cell mesothelioma. The differential diagnosis and immunohistochemical features in comparison with other clear cell neoplasms are discussed.

  12. SNOW CLEARING SERVICE WINTER 2001-2002

    CERN Multimedia

    ST-HM Group; Tel. 72202

    2001-01-01

    As usual at this time of the year, the snowing clearing service, which comes under the control of the Transport Group (ST-HM), is preparing for the start of snow-clearing operations (timetable, stand-by service, personnel responsible for driving vehicles and machines, preparation of useful and necessary equipment, work instructions, etc.) in collaboration with the Cleaning Service (ST-TFM) and the Fire Brigade (TIS-FB). The main difficulty for the snow-clearing service is the car parks, which cannot be properly cleared because of the presence of CERN and private vehicles parked there overnight in different parts of the parking areas. The ST-HM Transport Group would therefore like to invite you to park vehicles together in order to facilitate the access of the snow ploughs, thus allowing the car parks to be cleared more efficiently before the personnel arrives for work in the mornings.

  13. Dendritic immune cell densities in the central cornea associated with soft contact lens types and lens care solution types: a pilot study

    Directory of Open Access Journals (Sweden)

    Sindt CW

    2012-03-01

    Full Text Available Christine W Sindt1, Trudy K Grout1, D Brice Critser1, Jami R Kern2, David L Meadows21University of Iowa Hospitals and Clinics, Iowa City, IA; 2Alcon Research Ltd, Fort Worth, TX, USABackground: The purpose of this study was to assess whether differences in central corneal dendritic immune cell densities associated with combinations of soft contact lenses and lens care solutions could be detected by in vivo confocal microscopy.Methods: Participants were adults naïve to contact lens wear (n = 10 or who wore soft contact lenses habitually on a daily-wear schedule (n = 38 or on a study-assigned schedule for 30 days with daily disposable silicone hydrogel lenses (n = 15. Central corneas were scanned using an in vivo confocal microscope. Cell densities were compared among groups by demographic parameters, lens materials, and lens care solutions (polyhexamethylene biguanide [PHMB], polyquaternium-1 and myristamidopropyl dimethylamine [PQ/MAPD], peroxide, or blister pack solution [for daily disposable lenses].Results: Among lens wearers, no associations were observed between immune cell densities and age, gender, or years of lens-wearing experience. Mean cell density was significantly lower (P < 0.01 in nonwearers (29 ± 23 cells/mm2, n = 10 than in lens wearers (64 ± 71 cells/mm2, n = 53. Mean cell density was lower (P = 0.21 with traditional polymer lenses (47 ± 44 cells/mm2, n = 12 than with silicone hydrogel lenses (69 ± 77 cells/mm2, n = 41. Lowest to highest mean density of immune cells among lens wearers was as follows: PQ/MAPD solution (49 ± 28 cells/mm2, blister pack solution (63 ± 81 cells/mm2, PHMB solution (66 ± 44 cells/mm2, and peroxide solution (85 ± 112 cells/mm2.Conclusion: In this pilot study, in vivo confocal microscopy was useful for detecting an elevated immune response associated with soft contact lenses, and for identifying lens-related and solution-related immune responses that merit further research.Keywords: Clear Care

  14. New Management of Malignant Glaucoma by Phacoemulsification with Posterior Chamber Foldable Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    GeJian; GuoY

    1999-01-01

    Objective:To investigate the feasibility of phacoemulsification with posterior chamber foldable intraocular lens implantation in the management of malignant glaucoma. Patients and Methods:Fourteen patients with malignant glaucoma diagnosed in the Department of Glaucoma were enrolled in the study.12 patients developed malignant glaucoma after filtration surgery.1 developed after peripheral iridectomy.1 patient developed malignant glaucoma without any clear cause.Cataract phacoemulsification was performed.Posterior chamber intraocular foldable lens was implanted in 10 cases of patients.Results:All 14 patients were cured wiht normal intraocular pressure,normal anterior chamber depth and increased visual acuity.Conclusion:Phacoemulsification with posterior chamber foldable intraocular lens implantation is a good alternative in treating malignant glaucoma.

  15. High Altitude Clear Air Turbulence Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Air Force Flight Dynamics Laboratory conducted the High Altitude Clear Air Turbulence Project in the mid 1960s with the intention of better understanding air...

  16. Conjugate metamaterials and the perfect lens

    CERN Document Server

    Xu, Yadong; Xu, Lin; Chen, Huanyang

    2015-01-01

    In this letter, we show how transformation optics makes it possible to design what we call conjugate metamaterials. We show that these materials can also serve as substrates for making a subwavelength-resolution lens. The so-called "perfect lens", which is a lens that could focus all components of light (including propagating and evanescent waves), can be regarded as a limiting case, in which the respective conjugate metamaterials approach the characteristics of left-handed metamaterials, which have a negative refractive index.

  17. PMMA lens with high efficiency and reliability

    Science.gov (United States)

    Matsuzaki, Ichiro; Abe, Koji; Fujita, Katsuhiro

    2013-09-01

    Polymethyl Methacrylate (PMMA) Fresnel lenses are increasingly being used in concentrated photovoltaic (CPV) systems installed outdoors and, accordingly, emphasis is being placed on the durability of such lenses with regard to light transmittance when subject to ultraviolet (UV) light and dust exposure. Accelerated testing methods for evaluating durability under UV exposure were established, allowing development of a lens material with improved UV resistance. Simultaneously, through a proprietary molding method, a Fresnel lens that boasts favorable light concentration efficiency with little deformation even after prolonged outdoor use was developed. Moreover, the lens incorporates a new hard-coat finish that possesses sand durability and UV resistance comparable to that of tempered glass.

  18. Clear cell myoepithelial carcinoma ex pleomorphic adenoma

    Directory of Open Access Journals (Sweden)

    Nikhil R Rabade

    2014-01-01

    Full Text Available Pleomorphic adenoma is the most common epithelial neoplasm of lacrimal gland. A clear cell myoepithelial carcinoma arising in the background of pleomorphic adenoma is common in the salivary glands but very rare in the lacrimal glands. We report the case of a 27 year old man whose lacrimal gland pleomorphic adenoma recurred several times over a period of four years and ultimately evolved into a clear cell myoepithelial carcinoma ex pleomorphic adenoma.

  19. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available BACKGROUND: CO(2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. METHODOLOGY/PRINCIPAL FINDINGS: We measured CO(2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO(2 efflux. CO(2 efflux from soils declines from time of clearing from ∼10,600 tonnes km(-2 year(-1 in the first year to 3000 tonnes km(2 year(-1 after 20 years since clearing. Disturbing peat leads to short term increases in CO(2 efflux (27 umol m(-2 s(-1, but this had returned to baseline levels within 2 days. CONCLUSIONS/SIGNIFICANCE: Deforesting mangroves that grow on peat soils results in CO(2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks.

  20. Imaging of sub-surface nanostructures by dielectric planer cavity coupled microsphere lens

    Science.gov (United States)

    Guo, Minglei; Ye, Yong-Hong; Hou, Jinglei; Du, Bintao; Wang, Tian

    2017-01-01

    In this paper, a dielectric planar cavity between an object and a microsphere lens is fabricated and its effects on the imaging of sub-surface nanostructures have been studied. Using the dielectric planar cavity combined (DPCC) silica microsphere lens, our experimental results illustrate that the nanostructures of data-recorded Blu-ray disc can be clearly resolved. Optical images of the object with higher contrast and larger field of view (FOV) can be obtained, compared to the case when only a microsphere lens is used. For the 3.4 μm diameter microsphere lens combing a planar cavity with a thickness about 2.2 μm, the FOV is about 2.4 μm and the magnification is about 1.6. With the 3.4 μm diameter microsphere lens only, the FOV and magnification is 1.5 μm and 1.4 respectively. Theoretical analysis of the imaging properties is carried out by the characteristics of electric field distribution of microsphere lenses. The simulated results indicate that the dielectric planar cavity working as a Fabry-Pérot cavity can effectively enhance the coupling of optical information.

  1. Common path ball lens probe for optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Singh, Kanwarpal; Yamada, Daisuke; Tearney, Guillermo J.

    2016-02-01

    Background: Common path probes are highly desirable for optical coherence tomography (OCT) as they reduce system complexity and cost. In this work we report an all-fiber common path side viewing monolithic probe for coronary artery imaging. Methods: Our common path probe was designed for spectrometer based Fourier domain OCT at 1310 nm wavelength. Light from the fiber expands in the coreless fiber region and then focussed by the ball lens. Reflection from ball lens-air interface served as reference signal. The monolithic ball lens probe was assembled within a 560 µmouter diameter drive shaft which was attached to a rotary junction. The drive shaft was placed inside an outer, transparent sheath of 800 µm diameter. Results: With a source input power of 25 mW, we could achieve sensitivity of 100.5 dB. The axial resolution of the system was found to be 15.6 µm in air and the lateral resolution (full width half maximum) was approximately 49 µm. As proof of principal, images of skin acquired using this probe demonstrated clear visualization of the stratum corneum, epidermis, and papillary dermis, along with sweat ducts. Conclusion: In this work we have demonstrated a monolithic, ball lens common, path probe for OCT imaging. The designed ball lens probe is easy to fabricate using a laser splicer. Based on the features and capability of common path probes to provide a simpler solution for OCT, we believe that this development will be an important enhancement for certain types of catheters.

  2. Clear Corneal Phacovitrectomy with Posterior Capsulorhexis and IOL Implantation in Management of Selective Vitreoretinal Cases

    Directory of Open Access Journals (Sweden)

    Ernest V. Boiko

    2015-01-01

    Full Text Available Purpose. To describe our technique, clear corneal phacovitrectomy with posterior capsulorhexis (CCPV, for the management of selected posterior segment intraocular foreign body (IOFB, posteriorly dislocated lens fragments (PDLF, and proliferative diabetic retinopathy (PDR cases. Methods. This was a single-center retrospective interventional case series. In 21 patients (21 eyes we performed phacovitrectomy through three clear corneal tunnel incisions (CCTI and posterior capsulorhexis to remove IOFB (n=8, PDLF from the vitreous cavity after complicated phacoemulsification (n=6, and vitreous hemorrhage and epiretinal membranes in PDR (n=7. The procedure was completed with implantation of a hydrophobic acrylic IOL through the CCTI. Results. The mean visual acuity (logMAR was 0.90 preoperative and improved to 0.26 over a mean follow-up of 8.7 months (range, 6–12 months. The intraocular lens was implanted into the capsular bag (n=12 or onto the anterior capsule (n=9. One PDR patient experienced an intraprocedural complication, hemorrhage from isolated fibrovascular adhesions. One IOFB patient developed apparent anterior proliferative vitreoretinopathy and required a repeat intervention. Conclusion. Selected vitreoretinal IOFB, PDLF, and PDR cases can be successfully managed by a combined surgical approach involving clear corneal phacovitrectomy with posterior capsulorhexis and implantation of an IOL, with good visual outcome and a low complication rate.

  3. Clear Corneal Phacovitrectomy with Posterior Capsulorhexis and IOL Implantation in Management of Selective Vitreoretinal Cases.

    Science.gov (United States)

    Boiko, Ernest V; Churashov, Sergey V; Kulikov, Alexei N; Maltsev, Dmitrii S

    2015-01-01

    Purpose. To describe our technique, clear corneal phacovitrectomy with posterior capsulorhexis (CCPV), for the management of selected posterior segment intraocular foreign body (IOFB), posteriorly dislocated lens fragments (PDLF), and proliferative diabetic retinopathy (PDR) cases. Methods. This was a single-center retrospective interventional case series. In 21 patients (21 eyes) we performed phacovitrectomy through three clear corneal tunnel incisions (CCTI) and posterior capsulorhexis to remove IOFB (n = 8), PDLF from the vitreous cavity after complicated phacoemulsification (n = 6), and vitreous hemorrhage and epiretinal membranes in PDR (n = 7). The procedure was completed with implantation of a hydrophobic acrylic IOL through the CCTI. Results. The mean visual acuity (logMAR) was 0.90 preoperative and improved to 0.26 over a mean follow-up of 8.7 months (range, 6-12 months). The intraocular lens was implanted into the capsular bag (n = 12) or onto the anterior capsule (n = 9). One PDR patient experienced an intraprocedural complication, hemorrhage from isolated fibrovascular adhesions. One IOFB patient developed apparent anterior proliferative vitreoretinopathy and required a repeat intervention. Conclusion. Selected vitreoretinal IOFB, PDLF, and PDR cases can be successfully managed by a combined surgical approach involving clear corneal phacovitrectomy with posterior capsulorhexis and implantation of an IOL, with good visual outcome and a low complication rate.

  4. Combined 23-gauge sutureless vitrectomy and clear corneal phacoemulsification for rhegmatogenous retinal detachment repair

    Institute of Scientific and Technical Information of China (English)

    Hoseok; Moon; Hee; Jin; Sohn; Dea; Yeong; Lee; Jong; Yeon; Lee; Dong; Heun; Nam

    2015-01-01

    AIM: To assess the outcomes of combined 23-gauge sutureless vitrectomy and clear corneal phacoemulsification with intraocular lens implantation for rhegmatogenous retinal detachment(RRD) repair.METHODS: This was a retrospective, consecutive,noncomparative, interventional case series of 30 eyes of30 patients who underwent combined sutureless vitrectomy and clear corneal cataract surgery for the repair of RRD. The principal outcome measures were primary anatomical success rate, reasons for redetachment, final visual acuity, and surgical complications.RESULTS: Primary reattachment was achieved in 27eyes(90.0%). The reasons for redetachment(3 eyes, 10%)were incomplete laser retinopexy, persistent chronic subretinal fluid, and proliferative vitreoretinopathy,respectively. The logarithm of the minimum angle of resolution visual acuity(mean±SD) improved from 0.76±0.74 preoperatively to 0. 21 ± 0. 37 6 months’ postoperatively(P <0.0001). Postoperative hypotony was not detected,but 1 eye( 3. 3 %) had increased intraocular pressure(30 mm Hg) with spontaneous resolution. No endophthalmitis developed during follow-up. Macular pucker was detected in 3 eyes(10.0%).· CONCLUSION: Combined 23-gauge sutureless vitrectomy and clear corneal phacoemulsification with intraocular lens implantation for RRD repair was proven safe and effective. It may provide not only the known advantages of conventional combined surgery, but also additional advantages such as less conjunctival fibrosis and the maintenance of stable intraocular pressure with low risks of postoperative hypotony and intraocular pressure elevation.

  5. Bionic intraocular lens with variable focus and integrated structure

    Science.gov (United States)

    Liang, Dan; Wang, Xuan-Yin; Du, Jia-Wei; Xiang, Ke

    2015-10-01

    This paper proposes a bionic accommodating intraocular lens (IOL) for ophthalmic surgery. The designed lens has a solid-liquid mixed integrated structure, which mainly consists of a support ring, elastic membrane, rigid lens, and optical liquid. The lens focus can be adjusted through the deformation of the lens front surface when compressed. The integrated structure of the IOL is presented, as well as a detailed description of the lens materials and fabrication process. Images under different radial pressures are captured, and the lens deformation process, accommodating range, density, and optical property are analyzed. The designed lens achieves a 14.6 D accommodating range under a radial pressure of 51.4 mN and a 0.24 mm alteration of the lens outer radius. The deformation property of the lens matches well with the characteristic of the eye and shows the potential to help patients fully recover their vision accommodation ability after the cataract surgery.

  6. Single clear corneal incision for glaucoma drainage device shortening in pediatric glaucoma.

    Science.gov (United States)

    Radke, Phillip M; Bitrian, Elena; Grajewski, Alana L

    2016-06-01

    Glaucoma drainage devices are commonly used for management of glaucoma in adults and children. With time, the position of the tube can change and cause damage such as corneal scarring, iris or lens contact, and uveitis. Most of these problems can be improved with tube shortening and/or excision of adherent iris or fibrous tissue. We describe a surgical technique that uses a single clear corneal incision to externalize and trim the shunt in pediatric patients. The technique has a short surgical. We review the indications and outcomes for this procedure in 13 eyes of 12 children who required shunt revision.

  7. Ensuring Safe Use of Contact Lens Solution

    Science.gov (United States)

    ... evaluating contact lens solutions and the development of Acanthamoeba keratitis, a rare but serious eye infection that's ... contact lenses to water has been associated with Acanthamoeba keratitis, a corneal infection that is resistant to ...

  8. Variable-focus cylindrical liquid lens array

    Science.gov (United States)

    Zhao, Wu-xiang; Liang, Dong; Zhang, Jie; Liu, Chao; Zang, Shang-fei; Wang, Qiong-hua

    2013-06-01

    A variable-focus cylindrical liquid lens array based on two transparent liquids of different refractive index is demonstrated. An elastic membrane divides a transparent reservoir into two chambers. The two chambers are filled with liquid 1 and liquid 2, respectively, which are of different refractive index. The micro-clapboards help liquid 1, liquid 2 and the elastic membrane form a cylindrical lens array. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. A demo lens array of positive optical power is developed and tested. Moreover, a potential application of the proposed lens array for autostereoscopic 3D displays is emphasized.

  9. Role of Aquaporin 0 in lens biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

  10. Shanghai Clearing House to Roll out Renminbi-denominated Copper Clearing Operations in Free Trade Zone

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>Clearing House Financial Markets Co.,Ltd.(Shanghai Clearing House)General Manager Xie Zhong told the media recently at the briefing of the international symposium of"Reform Deepening and Mechanism Innovation of the Post-crisis Kerb Market",Shanghai Clearing House will explore the feasibility of carrying out bond business in

  11. Role of Aquaporin 0 in lens biomechanics.

    Science.gov (United States)

    Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

  12. Specific eye-head coordination enhances vision in progressive lens wearers.

    Science.gov (United States)

    Rifai, Katharina; Wahl, Siegfried

    2016-09-01

    In uncorrected vision all combinations of eye and head positions are visually equivalent; thus, there is no need for a specific modification of eye-head coordination in young healthy observers. In contrast, the quality of visual input indeed strongly depends on eye position in the majority of healthy elderly drivers, namely in progressive additional lens (PALs) wearers. For a given distance, only specific combinations of eye and head position provide clear vision in a progressive lens wearer. However, although head movements are an integral part of gaze behavior, it is not known if eye-head coordination takes part in the enhancement of visual input in healthy individuals. In the current study we determined changes in eye-head coordination in progressive lens wearers in challenging tasks with high cognitive load, in the situation of driving. During a real-world drive on an urban round track in Stuttgart, gaze movements and head movements were measured in 17 PAL wearers and eye-head coordination was compared to 27 controls with unrestricted vision. Head movement behavior, specific to progressive lens wearers, was determined in head gain and temporal properties of head movements. Furthermore, vertical eye-head coordination was consistent only among PAL wearers. The observed differences in eye-head coordination clearly demonstrate a contribution of head movements in the enhancement of visual input in the healthy human visual system.

  13. A case of Alagille syndrome complicated by intraocular lens subluxation and rhegmatogenous retinal detachment

    Directory of Open Access Journals (Sweden)

    Fukumoto M

    2013-07-01

    Full Text Available Masanori Fukumoto, Tsunehiko Ikeda, Tetsuya Sugiyama, Mari Ueki, Takaki Sato, Eisuke Ishizaki Department of Ophthalmology, Osaka Medical College, Takatsuki City, Japan Abstract: This case report describes a case of Alagille syndrome with developing intraocular lens subluxation and rhegmatogenous retinal detachment 4 years after cataract surgery. A 15-year-old female patient with Alagille syndrome-associated cataracts in both eyes underwent phacoemulsification aspiration and intraocular lens implantation. Four years postoperative, intraocular lens subluxation developed in her left eye. For treatment, extraction of the dislocated intraocular lens, anterior vitrectomy, and intraocular lens fixation was performed. Three weeks later, the patient developed rhegmatogenous retinal detachment, which was well-treated by pars plana vitrectomy. Cataract surgery needs to be performed carefully in patients with Alagille syndrome due to the weakness of the zonule of Zinn. Careful postoperative observation is necessary for patients with Alagille syndrome who have undergone intraocular surgery in order to facilitate early detection of a possible rhegmatogenous retinal detachment. Keywords: Alagille syndrome, cataract, retina, surgery

  14. Veselago lens by photonic hyper-crystals

    CERN Document Server

    Huang, Zun

    2014-01-01

    An imaging system functioning as a Veselago lens has been proposed based on the novel concept of photonic "hyper-crystal" -- an artificial optical medium synthesizing the properties of hyperbolic materials and photonic crystals. This Veselago lens shows a nearly constant negative refractive index and substantially reduced image aberrations. It can find potential applications in photolithography and hot-spots detection of silicon-based integrated circuits.

  15. Evolution and the Calcite Eye Lens

    CERN Document Server

    Williams, Vernon L

    2013-01-01

    Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.

  16. Environmental standards for intraocular lens implantation.

    Science.gov (United States)

    Crawford, B A; Kaufman, D V

    1984-02-01

    Successful implantation of prosthetic devices depends upon their freedom from postoperative inflammation and infection. Techniques and lessons learned in orthopaedic and other implant surgery should be applied to intraocular lens implantation. The avoidance of contamination by particles and micro-organisms is one essential principle of the surgical procedure. Practical steps are described to reduce both types of contamination. These measures taken together are recommended for adoption as a standard of environmental safety for lens implantation.

  17. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    OpenAIRE

    Elena Bonafonte Marquez; Sergio Bonafonte Royo

    2015-01-01

    We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL) implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for i...

  18. Introduction to the development of intraocular lens

    Science.gov (United States)

    Li, Yifan; Peng, Runling; Hu, Shuilan; Wei, Maowei; Chen, Jiabi

    2013-08-01

    In order to cure the cataract disease or injuries in eyes, intraocular lens(IOL) has been studied all the time to replace the crystalline lens in human eyes. Researches on IOL are started early from 19th century, and it develops greatly in the hundreds years after. This article introduces several main kinds of IOLs that appear in the development history of IOL, and raises the double-liquid zoom IOL based on electrowetting, which will be the trend of IOL study.

  19. A Spectrometer Based on Diffractive Lens

    Institute of Scientific and Technical Information of China (English)

    WANG Daoyi; YAN Yingbai; JIN Guofan; WU Minxian

    2001-01-01

    A novel spectrometer is designed based on diffractive lens. It is essentially a flat field spectrometer. All the focal points are along the optical axis. Besides, all the asymmetrical aberrations vanish in our mounting. Thus low aberration can be obtained. In this article a diffractive lens is modeled as a special grating and analyzed by using a grating-based method. And a stigmatic point is introduced to reduce the aberrations.

  20. In vivo human crystalline lens topography

    OpenAIRE

    Ortiz, Sergio; Pérez Merino, Pablo; Gambra, Enrique; Castro, Alberto; Marcos, Susana

    2012-01-01

    Custom high-resolution high-speed anterior segment spectral domain optical coherence tomography (OCT) was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo. The system was provided with custom algorithms for denoising and segmentation of the images, as well as for fan (scanning) and optical (refraction) distortion correction, to provide fully quantitative images of the anterior and posterior crystalline lens surfaces. The method was tested on an artificial eye ...

  1. Photon nanojet lens: design, fabrication and characterization

    Science.gov (United States)

    Xu, Chen; Zhang, Sichao; Shao, Jinhai; Lu, Bing-Rui; Mehfuz, Reyad; Drakeley, Stacey; Huang, Fumin; Chen, Yifang

    2016-04-01

    In this paper, a novel nanolens with super resolution, based on the photon nanojet effect through dielectric nanostructures in visible wavelengths, is proposed. The nanolens is made from plastic SU-8, consisting of parallel semi-cylinders in an array. This paper focuses on the lens designed by numerical simulation with the finite-difference time domain method and nanofabrication of the lens by grayscale electron beam lithography combined with a casting/bonding/lift-off transfer process. Monte Carlo simulation for injected charge distribution and development modeling was applied to define the resultant 3D profile in PMMA as the template for the lens shape. After the casting/bonding/lift-off process, the fabricated nanolens in SU-8 has the desired lens shape, very close to that of PMMA, indicating that the pattern transfer process developed in this work can be reliably applied not only for the fabrication of the lens but also for other 3D nanopatterns in general. The light distribution through the lens near its surface was initially characterized by a scanning near-field optical microscope, showing a well defined focusing image of designed grating lines. Such focusing function supports the great prospects of developing a novel nanolithography based on the photon nanojet effect.

  2. Lens Biology is a Dimension of Neurobiology.

    Science.gov (United States)

    Frederikse, Peter; Kasinathan, Chinnaswamy

    2017-02-04

    There is a second cell type in your body that expresses scores of the most intensively studied genes in neuroscience and exclusively shares critical interdependent modes of molecular regulation that include a network first described as responsible for the basic bifurcation of neuronal from non-neuronal gene expression in vertebrates. Neurons and lens cells are among the most ancient animal cell types, yet neurons have an exclusive status also attributed to roles underlying sensation, movement, and cognition. However, this status is challenged by cells in the lens of the eye. The extent and detail of internally consistent parallels with neuron biology now catalogued in their second native cell type in the lens provide a detailed model of interdependent neuron gene expression in lens development and non-neuronal role in vision. These comprehensive parallels identify the lens as a dimension of neurobiology and a fundamental new perspective on neurodevelopment and its disorders. Finally, this understanding identifies that hallmark neuronal gene expression and key modes of associated molecular regulation evolved in tandem in the lens.

  3. Clear plastic cups: a childhood choking hazard.

    Science.gov (United States)

    Weiss, R L; Goldstein, M N; Dharia, A; Zahtz, G; Abramson, A L; Patel, M

    1996-11-01

    The disposable plastic beverage cup is not usually regarded as hazardous to young children. Certain varieties of these products however, are manufactured from a brittle, clear plastic that easily cracks and fragments. While most conscientious parents keep their children safe from peanuts, balloons, and other known choking hazards, a child can surreptitiously bite a cup edge and aspirate the fragment. We report two cases of foreign body aspiration involving clear plastic cups that went undetected one of which remained 21 months following a negative rigid bronchoscopy. Diagnostic difficulties are related to the transparency and radiolucency of these objects. When suspicious of foreign body aspiration in children, otolaryngologists should inquire about the availability of clear plastic cups in the household and be mindful of the diagnostic pitfalls. Further investigations including CT scanning and repeat bronchoscopy may be helpful in cases of suspected missed foreign bodies. An educational campaign aimed at prevention and placement of product package warning labels should be established.

  4. Clear cell carcinoma of the female genital tract (not everything is as clear as it seems).

    Science.gov (United States)

    Offman, Saul L; Longacre, Teri A

    2012-09-01

    Clear cell carcinoma has a storied history in the female genital tract. From the initial designation of ovarian clear cell adenocarcinoma as "mesonephroma" to the linkage between vaginal clear cell carcinoma and diethylstilbestrol exposure in utero, gynecologic tract clear cell tumors have puzzled investigators, posed therapeutic dilemmas for oncologists, and otherwise presented major differential diagnostic challenges for pathologists. One of the most common errors in gynecologic pathology is misdiagnosis of clear cell carcinoma, on both frozen section and permanent section. Given the poor response to platinum-based chemotherapy for advanced-stage disease and increased risk of thromboembolism, accurate diagnosis of clear cell carcinoma is important in the female genital tract. This review (1) presents the clinical and pathologic features of female genital tract clear cell carcinomas; (2) highlights recent molecular developments; (3) identifies areas of potential diagnostic confusion; and (4) presents solutions for these diagnostic problems where they exist.

  5. The management of clear cell sarcoma

    NARCIS (Netherlands)

    Kuiper, DR; Hoekstra, HJ; Veth, RPH; Wobbes, T

    2003-01-01

    Clear cell sarcoma is a rare soft tissue tumour, constituting approximately 1% of all soft tissue sarcomas. Prognosis is reported to be poor due to the great propensity to metastasise regionally and distantly. In this paper, we report the surgical experience of two university hospitals. Both disease

  6. Clearing and settlement of exchange traded derivatives

    OpenAIRE

    John McPartland

    2009-01-01

    Derivatives are a class of financial instruments that derive their value from some underlying commodity, security, index, or other asset. Futures and options are common forms of derivatives. This article explains how clearing and settlement systems for exchange traded derivatives work.

  7. PROSE scleral lens: a novel aid for staged eyelid reconstruction.

    Science.gov (United States)

    Samimi, David B; Chiu, Gloria B; Burnstine, Michael A

    2014-01-01

    A 50-year-old man presented with a papillomatous tarsoconjunctival tumor involving the medial two-thirds of the left upper eyelid. Office biopsy revealed papillary squamous cell carcinoma (SCCA). Rapid tumor growth with caruncular and forniceal conjunctival involvement continued, despite a trial of weekly interferon-α2b intralesional injection therapy. Surgical excision with clear margins resulted in a large upper eyelid defect. The suspicion for recurrence remained, given the aggressive nature of the tumor. A temporary prosthetic replacement of the ocular surface ecosystem (PROSE) scleral lens was fit for preservation of the ocular surface and visual function during a 1-month observation period. No evidence of recurrence was noted, and the eyelid defect was successfully reconstructed with a Cutler-Beard procedure. Local disease was controlled; unfortunately, metastatic disease was found in the ipsilateral parotid gland 1 year later. Aggressive surgical removal is recommended in interferon-α2b nonresponsive SCCA tumors. The PROSE scleral contact lens may serve as a useful adjunct for the maintenance of a healthy ocular surface and visual function during delayed eyelid defect repair.

  8. A medieval fallacy: the crystalline lens in the center of the eye

    Directory of Open Access Journals (Sweden)

    Leffler CT

    2016-04-01

    Full Text Available Christopher T Leffler,1 Tamer M Hadi,2 Akrithi Udupa,1 Stephen G Schwartz,3 Daniel Schwartz1 1Department of Ophthalmology, Virginia Commonwealth University, Richmond, VA, 2Graduate School of Medicine, University of Tennessee Medical Center, Knoxville, TN, 3Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA Objective: To determine whether, as most modern historians have written, ancient Greco-Roman authors believed the crystalline lens is positioned in the center of the eye. Background: Historians have written that statements about cataract couching by Celsus, or perhaps Galen of Pergamon, suggested a centrally located lens. Celsus specifically wrote that a couching needle placed intermediate between the corneal limbus and the lateral canthus enters an empty space, presumed to represent the posterior chamber. Methods: Ancient ophthalmic literature was analyzed to understand where these authors believed the crystalline lens was positioned. In order to estimate where Celsus proposed entering the eye during couching, we prospectively measured the distance from the temporal corneal limbus to the lateral canthus in 30 healthy adults. Results: Rufus of Ephesus and Galen wrote that the lens is anterior enough to contact the iris. Galen wrote that the lens equator joins other ocular structures at the corneoscleral junction. In 30 subjects, half the distance from the temporal corneal limbus to the lateral canthus was a mean of 4.5 mm (range: 3.3–5.3 mm. Descriptions of couching by Celsus and others are consistent with pars plana entry of the couching needle. Anterior angulation of the needle would permit contact of the needle with the lens. Conclusion: Ancient descriptions of anatomy and couching do not establish the microanatomic relationships of the ciliary region with any modern degree of accuracy. Nonetheless, ancient authors, such as Galen and Rufus, clearly understood that the lens is located anteriorly

  9. DISSECTING THE GRAVITATIONAL LENS B1608+656. I. LENS POTENTIAL RECONSTRUCTION

    NARCIS (Netherlands)

    Suyu, S. H.; Marshall, P. J.; Blandford, R. D.; Fassnacht, C. D.; Koopmans, L. V. E.; McKean, J. P.; Treu, T.

    2009-01-01

    Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. Lens systems with extended source-intensity distributions are particularly useful for this purpose since they provide additional constraints on the lens potential ( m

  10. Gravitational binary-lens events with prominent effects of lens orbital motion

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.; Han, C.; Choi, J.-Y. [Department of Physics, Institute for Astrophysics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Udalski, A.; Szymański, M. K.; Kubiak, M.; Soszyński, I.; Pietrzyński, G.; Poleski, R.; Ulaczyk, K.; Pietrukowicz, P.; Kozłowski, S.; Skowron, J.; Wyrzykowski, Ł. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Gould, A.; Gaudi, B. S. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Beaulieu, J.-P. [Institut d' Astrophysique de Paris, UMR 7095 CNRS-Université Pierre and Marie Curie, 98bis Bd Arago, F-75014 Paris (France); Tsapras, Y. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Depoy, D. L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Dong, Subo [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Collaboration: OGLE Collaboration; μFUN Collaboration; PLANET Collaboration; RoboNet Collaboration; and others

    2013-12-01

    Gravitational microlensing events produced by lenses composed of binary masses are important because they provide a major channel for determining physical parameters of lenses. In this work, we analyze the light curves of two binary-lens events, OGLE-2006-BLG-277 and OGLE-2012-BLG-0031, for which the light curves exhibit strong deviations from standard models. From modeling considering various second-order effects, we find that the deviations are mostly explained by the effect of the lens orbital motion. We also find that lens parallax effects can mimic orbital effects to some extent. This implies that modeling light curves of binary-lens events not considering orbital effects can result in lens parallaxes that are substantially different from actual values and thus wrong determinations of physical lens parameters. This demonstrates the importance of routine consideration of orbital effects in interpreting light curves of binary-lens events. It is found that the lens of OGLE-2006-BLG-277 is a binary composed of a low-mass star and a brown dwarf companion.

  11. Effect of infusion bottle height on lens power after lens refilling with and without a plug

    NARCIS (Netherlands)

    Koopmans, SA; Terwee, T; Haitjema, HJ; Kooijman, AC; Barkhof, J

    2003-01-01

    Purpose: To evaluate the influence of intraoperative infusion bottle height on the power of refilled pig lenses. Setting: Research Laboratory, Pharmacia Intraocular Lens Manufacturing Plant, Groningen, The Netherlands. Methods: This study comprised 2 groups of pig eyes. In 1 group, the lens was refi

  12. The Sloan Lens ACS Survey. V. The full ACS strong-lens sample

    NARCIS (Netherlands)

    Bolton, Adam S.; Burles, Scott; Koopmans, Leon V. E.; Treu, Tommaso; Gavazzi, Raphael; Moustakas, Leonidas A.; Wayth, Randall; Schlegel, David J.

    2008-01-01

    We present the definitive data for the full sample of 131 strong gravitational lens candidates observed with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope by the Sloan Lens ACS (SLACS) Survey. All targets were selected for higher redshift emission lines and lower redshift c

  13. Small Incision Cataract Surgery (SICS with Clear Corneal Incision and SICS with Scleral Incision – A Comparative Study

    Directory of Open Access Journals (Sweden)

    Md Shafiqul Alam

    2014-01-01

    Full Text Available Background: Age related cataract is the leading cause of blindness and visual impairment throughout the world. With the advent of microsurgical facilities simple cataract extraction surgery has been replaced by small incision cataract surgery (SICS with posterior chamber intra ocular lens implant, which can be done either with clear corneal incision or scleral incision. Objective: To compare the post operative visual outcome in these two procedures of cataract surgery. Materials and method: This comparative study was carried out in the department of Ophthalmology, Delta Medical College & Hospital, Dhaka, Bangladesh, during the period of January 2010 to December 2012. Total 60 subjects indicated for age related cataract surgery irrespective of sex with the age range of 40-80 years with predefined inclusion and exclusion criteria were enrolled in the study. Subjects were randomly and equally distributed in 2 groups; Group A for SICS with clear corneal incision and group B for SICS with scleral incision. Post operative visual out come was evaluated by determining visual acuity and astigmatism in different occasions and was compared between groups. Statistical analysis was done by SPSS for windows version12. Results: The highest age incidence (43.3% was found between 61 to 70 years of age group. Among study subjects 40 were male and 20 were female. Preoperative visual acuity and astigmatism were evenly distributed between groups. Regarding postoperative unaided visual outcome, 6/12 or better visual acuity was found in 19.98% cases in group A and 39.6% cases in group B at 1st week. At 6th week 6/6 vision was found in 36.3% in Group A and 56.1% in Group B and 46.2% in group A and 66% in group B without and with correction respectively. With refractive correction, 6/6 vision was attained in 60% subjects of group A and 86.67% of group B at 8th week. Post operative visual acuity was statistically significant in all occasions. Postoperative astigmatism of

  14. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  15. A 2D correlation Raman spectroscopy analysis of a human cataractous lens

    Science.gov (United States)

    Sacharz, Julia; Wesełucha-Birczyńska, Aleksandra; Paluszkiewicz, Czesława; Chaniecki, Piotr; Błażewicz, Marta

    2016-11-01

    This work is a continuation of our study of a cataractous human eye lens removed after phacoemulsification surgery. There are clear differences in the lens colors that allowed for distinguishing two opaque phases in the obtained biological material: the white- and yellow-phase. The Raman spectroscopy and 2D correlation spectroscopy method were used to trace a pathologically altered human cataract lens at a molecular level. Although the Raman spectra of these two phases are relatively similar, taking advantage of 2D correlation, and considering time as an external perturbation, the synchronous and asynchronous spectra were obtained showing completely different patterns. Prominent synchronous auto-peaks appear at 3340, 2920, 1736, 1665 and 1083 cm-1 for the white-, and at 2929 and 1670 cm-1 for the yellow phase. The white phase is characterized by intensive asynchronous peaks at -(2936, 3360), -(1650, 1674) and +(1620,1678). The modifications in the water contained in the white phase structure are ahead of the changes in the protein (CH3-groups), furthermore changes in β-conformation are asynchronous with respect to the α-structure. The yellow phase demonstrates asynchronous peaks: +(2857, 2928), +(1645,1673), +(1663, 1679), and +(1672,1707). These illustrate concomitant modifications in the β- and unordered conformation. Both forms of cataractous human eye lens, white- and yellow-phases, are degenerate forms of the eye lens proteins, both are arranged in a different way. The main differences are observed for the amide I, methyl, methylene and Osbnd H vibrational band region. The effect of Asp, Glu and Tyr amino acids in cataractous lens transformations was observed.

  16. Multiphoton microscopy of cleared mouse organs

    Science.gov (United States)

    Parra, Sonia G.; Chia, Thomas H.; Zinter, Joseph P.; Levene, Michael J.

    2010-05-01

    Typical imaging depths with multiphoton microscopy (MPM) are limited to less than 300 μm in many tissues due to light scattering. Optical clearing significantly reduces light scattering by replacing water in the organ tissue with a fluid having a similar index of refraction to that of proteins. We demonstrate MPM of intact, fixed, cleared mouse organs with penetration depths and fields of view in excess of 2 mm. MPM enables the creation of large 3-D data sets with flexibility in pixel format and ready access to intrinsic fluorescence and second-harmonic generation. We present high-resolution images and 3-D image stacks of the brain, small intestine, large intestine, kidney, lung, and testicle with image sizes as large as 4096×4096 pixels.

  17. Roadmap-Based Level Clearing of Buildings

    KAUST Repository

    Rodriguez, Samuel

    2011-01-01

    In this paper we describe a roadmap-based approach for a multi-agent search strategy to clear a building or multi-story environment. This approach utilizes an encoding of the environment in the form of a graph (roadmap) that is used to encode feasible paths through the environment. The roadmap is partitioned into regions, e.g., one per level, and we design region-based search strategies to cover and clear the environment. We can provide certain guarantees within this roadmap-based framework on coverage and the number of agents needed. Our approach can handle complex and realistic environments where many approaches are restricted to simple 2D environments. © 2011 Springer-Verlag.

  18. Clear cell odontogenic carcinoma: A rare case

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2015-01-01

    Full Text Available Clear cell odontogenic carcinoma is a rare neoplasm with very few cases reported in the literature. We report a case of a 50-year-old female patient with the malignancy at a less common location. Diagnosis was given based on the histopathologic findings. The demographic data and understanding for this tumor needs to be strengthened by reporting all new cases, which are diagnosed, in literature.

  19. Internet compromise clears way for WSIS agreement

    CERN Multimedia

    Ermert, M

    2003-01-01

    A working group under the leadership of United Nations Secretary General Kofi Annan himself will try to resolve the deep differences on the question of Internet governance, officials said here. The group, whose exact membership wasn't immediately clear, is to propose a solution to the controversial issue that has given negotiators at the World Summit of the Information Society (WSIS) a headache (1/2 page).

  20. [Representation and mathematical analysis of human crystalline lens].

    Science.gov (United States)

    Tălu, Stefan; Giovanzana, Stefano; Tălu, Mihai

    2011-01-01

    The surface of human crystalline lens can be described and analyzed using mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the lens. The mathematical models used in lens biomechanics allow the study and the behavior of crystalline lens on variables and complex dynamic loads. Also, the lens biomechanics has the potential to improve the results in the development of intraocular lenses and cataract surgery. The paper presents the most representative mathematical models currently used for the modeling of human crystalline lens, both optically and biomechanically.

  1. Optical clearing of muscle with propylene glycol

    Science.gov (United States)

    Oliveira, Luís; Lage, Armindo; Clemente, Manuel Pais; Tuchin, Valery V.

    2010-02-01

    Skeletal muscle presents an internal fibrous structure. The existence of muscle fibers surrounded by interstitial fluid originates an internal step refractive index profile that causes light scattering. One way to minimize this effect inside a muscle is to perform an optical clearing treatment, using an adequate solution that presents a refractive index higher than the interstitial fluid. We have studied muscle spectral transmittance during sample immersion in propylene glycol. With the collection of transmittance spectra registered during a period of 20 minutes of immersion we could represent spectral transmittance evolution for several wavelengths and verify that the tissue samples have become more translucent. The optical clearing effect created in the tissue samples was characterized by an increase of 45% above the natural transmittance and the variations observed in tissue mass, pH and global refractive index. We also identified the initial mechanisms of agent diffusion into the tissue and consequent tissue dehydration from the spectral transmittance evolution. The histological analysis of variations caused in the internal structure of the tissues permitted to better explain the optical clearing effect created. Considering a mathematical model developed in previous studies, we could estimate the amount of agent that was inserted into the tissue samples.

  2. Imaging characteristics of a volume holographic lens

    Science.gov (United States)

    Yang, Jing; Jiang, Zhu-qing; Xu, Zhi-qiang; Liu, Shao-jie; Sun, Ya-jun; Tao, Shi-quan

    2009-07-01

    A volume holographic grating lens can reconstruct the three-dimensional information by conducting multiple optical slicing of an object based on Bragg selectivity of the volume holographic grating. In this paper, we employ the point-spread function of volume holographic imaging system to theoretically analyze its imaging resolution. In the experiments, the volume holographic gratings are made with a spherical reference (SR) and a planar reference (PR), respectively, and used as volume holographic imaging lens in our imaging system. The longitudinal and lateral defocusing characteristics of volume holographic lens with SR and with PR are investigated experimentally by displacing the interested objects from original reference location, respectively. The effects of the parameters of the volume holographic lens on the longitudinal and lateral resolution are also discussed. The experimental results show that increasing the size of the volume holographic lens can improve the depth resolution, and in particular, it has greater influence on SR VHI. The lateral selectivity of SR VHI is more sensitive than that of PR VHI, and the Bragg degenerate diffraction of PR VHI on the y axis is obviously observed.

  3. Apoptosis in the lens anlage of the heritable lens aplastic mouse (lap mouse).

    Science.gov (United States)

    Aso, S; Tashiro, M; Baba, R; Sawaki, M; Noda, S; Fujita, M

    1998-08-01

    Adult homozygous lap mice show various eye abnormalities, such as aphakia, retinal disorganization, and dysplasia of the cornea and anterior chamber. In the fetal eye of a homozygous lap mouse, the lens placode seems to develop normally. However, the lens vesicle progresses abnormally to form a mass of cells without a cavity, and the mass vanishes soon afterward. We examined cell death in the lens anlage of this mutant. The lens anlagen of homozygous lap and normal mice from days 10 to 12 of gestation were observed by light microscopy after DNA end-labeling by immunohistochemistry and by transmission electron microscopy. By light microscopy, a slight frequency of cell death was detected in the lens anlage encircling the surface ectoderm and in the anlage or in the anlage of both homozygous lap mice and normal mice at day 10 of gestation. Cell death was seen in the lens anlage encircling the surface ectoderm in the normal mouse and sporadically in the anlage of the homozygous lap mouse at day 10.5 of gestation. Cell death was visible at the area of the lens vesicle attached to the surface ectoderm and encircling the surrounding surface ectoderm in the normal mouse, and in the lens anlage encircling the surface ectoderm and the apex areas of the lens anlage in the homozygous lap mouse at day 11 of gestation. At day 12 of gestation, almost no cell death was observed in the lens anlage of the normal mouse. However, extensive areas of cell death were still seen in the lens anlage at its apex, at the inner region, and encircling the surface ectoderm in the homozygous lap mouse. Electron microscopic observation showed that the dead cells observed in the lens anlagen by light microscopy in normal and lap mice are the result of apoptosis. In lap mice, cells with cytoplasmic condensation were observed mainly at days 10 and 10.5 of gestation. Many apoptotic bodies which had been phagocytosed by adjacent cells were seen predominantly at day 11 of gestation. At day 12 of

  4. The Nordic power market: Are there alternatives to expensive clearing?; Alternativer til kostbar clearing?

    Energy Technology Data Exchange (ETDEWEB)

    Nerdrum, Per Kaare; Poulsson, Christian

    2003-07-01

    The Enron scandal of 2002 has set focus on counter party risk in the Nordic power market and is an important cause of increased clearing of bilateral financial power contracts. The article discusses whether expensive clearing is always the best tool for dealing with counter party risk.

  5. Pigment Epithelium-derived Factor in Cataractous Aqueous Humor and Lens Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Tian Liu; Yizhi Liu; Mingxing Wu

    2006-01-01

    Purpose:To study the characteristics of PEDF in cataractous aqueous humor and its expression in human lens epithelium.Methods:The PEDF concentration in the aqueous humor was measured by enzyme linked immunosorbent assay in senile (130cases) and congenital (18cases) cataract patients who underwent cataract phacoemulsification extraction surgery. Anterior lens capsular specimens were obtained from these patients to count lens epithelial cells(LEC) density. The Lens Opacities Classification System Ⅲ was used to classify the senile cataracts as cortical, nuclear, posterior subcapsular and mixed types of opacity, and quantitative analysis of the nuclear opacities was performed by Pentacam Scheimpflug imaging system. Anterior lens capsular specimens from another senile(10cases) and congenital (10cases) cataract were collected for immunofluorescence with polyclonal antibodies specific to human pigment epithelium-derived factor(PEDF).Results:The mean aqueous level of PEDF was(178. 9±87. 5)ng/ml, and there was negative linear correlation of PEDF level and age (r=0. 811, P < 0. 001) . In senile cases, the aqueous PEDF concentration decreased with increasing nuclear opacities(r=0. 447, P < 0.01 ), and the mean PEDF level in nuclear cataract was significantly lower than that in posterior subcapsular opacity (P < 0.01 ) . PEDF immunostaining was detected in LEC of all capsular specimens.Conclusion :The PEDF level in human aqueous humor is related to age, types of cataracts and lens opacity. PEDF also express in human LEC. The study results suggest PEDF may regulate and/or protect LEC by paracrine and autocrine, and lack of PEDF may play a role in cataractogenesis.

  6. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Science.gov (United States)

    Bugalho, R.; Carriço, B.; Ferreira, C. S.; Frade, M.; Ferreira, M.; Moura, R.; Ortigão, C.; Pinheiro, J. F.; Rodrigues, P.; Rolo, I.; Silva, J. C.; Trindade, A.; Varela, J.

    2009-10-01

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Português de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 × 2 × 20 mm3 LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean CDOI-1 is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  7. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Energy Technology Data Exchange (ETDEWEB)

    Bugalho, R; Carrico, B; Ferreira, C S; Frade, M; Ferreira, M; Moura, R; Ortigao, C; Pinheiro, J F; Rodrigues, P; Rolo, I; Silva, J C; Trindade, A; Varela, J [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Av. Elias Garcia 14-1, 1000-149 Lisboa (Portugal)], E-mail: frade@lip.pt

    2009-10-15

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Portugues de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 x 2 x 20 mm{sup 3} LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean C{sub DOI}{sup -1} is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  8. An inverse and analytic lens design method

    CERN Document Server

    Lu, Yang

    2016-01-01

    Traditional lens design is a numerical and forward process based on ray tracing and aberration theory. This method has limitations because the initial configuration of the lens has to be specified and the aberrations of the lenses have to considered. This paper is an initial attempt to investigate an analytic and inverse lens design method, called Lagrange, to overcome these barriers. Lagrange method tries to build differential equations in terms of the system parameters and the system input and output (object and image). The generalized Snell's law in three dimensional space and the normal of a surface in fundamental differential geometry are applied. Based on the Lagrange method equations for a single surface system are derived which can perfectly image a point object.

  9. The Frontier Fields Lens Modeling Comparison Project

    CERN Document Server

    Meneghetti, M; Coe, D; Contini, E; De Lucia, G; Giocoli, C; Acebron, A; Borgani, S; Bradac, M; Diego, J M; Hoag, A; Ishigaki, M; Johnson, T L; Jullo, E; Kawamata, R; Lam, D; Limousin, M; Liesenborgs, J; Oguri, M; Sebesta, K; Sharon, K; Williams, L L R; Zitrin, A

    2016-01-01

    Gravitational lensing by clusters of galaxies offers a powerful probe of their structure and mass distribution. Deriving a lens magnification map for a galaxy cluster is a classic inversion problem and many methods have been developed over the past two decades to solve it. Several research groups have developed techniques independently to map the predominantly dark matter distribution in cluster lenses. While these methods have all provided remarkably high precision mass maps, particularly with exquisite imaging data from the Hubble Space Telescope (HST), the reconstructions themselves have never been directly compared. In this paper, we report the results of comparing various independent lens modeling techniques employed by individual research groups in the community. Here we present for the first time a detailed and robust comparison of methodologies for fidelity, accuracy and precision. For this collaborative exercise, the lens modeling community was provided simulated cluster images -- of two clusters Are...

  10. Catadioptric aberration correction in cathode lens microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tromp, R.M. [IBM T.J. Watson Research Center, PO Box 218, Yorktown Heights, NY 10598 (United States); Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Niels Bohrweg 2, 2333 CA Leiden (Netherlands)

    2015-04-15

    In this paper I briefly review the use of electrostatic electron mirrors to correct the aberrations of the cathode lens objective lens in low energy electron microscope (LEEM) and photo electron emission microscope (PEEM) instruments. These catadioptric systems, combining electrostatic lens elements with a reflecting mirror, offer a compact solution, allowing simultaneous and independent correction of both spherical and chromatic aberrations. A comparison with catadioptric systems in light optics informs our understanding of the working principles behind aberration correction with electron mirrors, and may point the way to further improvements in the latter. With additional developments in detector technology, 1 nm spatial resolution in LEEM appears to be within reach. - Highlights: • The use of electron mirrors for aberration correction in LEEM/PEEM is reviewed. • A comparison is made with similar systems in light optics. • Conditions for 1 nm spatial resolution are discussed.

  11. Louvre-Lens : le Louvre autrement

    OpenAIRE

    Audrey Bodéré

    2010-01-01

    ∙ Quels sont les enjeux du projet Louvre-Lens pour le Musée du Louvre ? Par ce projet, le Louvre participe tant à la politique de décentralisation qu’à une volonté de démocratisation culturelle, en allant à la rencontre de nouveaux publics. Mais le projet scientifique et culturel du Louvre-Lens (PSC) précise aussi que l'un des principaux défis est d'oser le « Louvre autrement ». La présentation des collections est donc repensée pour traduire le monde Louvre à Lens. Le lien entre le Louvre Par...

  12. Louvre-Lens : le Louvre autrement

    Directory of Open Access Journals (Sweden)

    Audrey Bodéré

    2010-04-01

    Full Text Available ∙ Quels sont les enjeux du projet Louvre-Lens pour le Musée du Louvre ? Par ce projet, le Louvre participe tant à la politique de décentralisation qu’à une volonté de démocratisation culturelle, en allant à la rencontre de nouveaux publics. Mais le projet scientifique et culturel du Louvre-Lens (PSC précise aussi que l'un des principaux défis est d'oser le « Louvre autrement ». La présentation des collections est donc repensée pour traduire le monde Louvre à Lens. Le lien entre le Louvre Par...

  13. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-12-19

    The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

  14. ELECTRON MICROSCOPY STUDIES OF LENS FROM TWO CASES OF OCULAR SIDEROSIS

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    Cases report Case 1: A 50-year-old man was injuried by iron filings on his left eye. He was admitted to our hospital on Feb. 3, 1987. On examination, his visual acuity was 20/15 OD and 20/500 OS. Left eye: The cornea was clear, the anterior chamber depth was 3 CT, tyndall(-). Iris pattern is clear, pupil was 3.5×3.5mm. Dilated pupil examination: There were scattered brown-yellow ironrust under anterior capsule and the lens cortex had become totally opaque. Nuclear, posterior capsule and fundus can't be ...

  15. Calculation of the transverse kicks generated by the bends of a hollow electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Stancari, Giulio

    2014-03-25

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam in high-energy accelerators. They were used in the Fermilab Tevatron collider for abort-gap clearing, beam-beam compensation, and halo scraping. A beam-beam compensation scheme based upon electron lenses is currently being implemented in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. This work is in support of a conceptual design of hollow electron beam scraper for the Large Hadron Collider. It also applies to the implementation of nonlinear integrable optics with electron lenses in the Integrable Optics Test Accelerator at Fermilab. We consider the axial asymmetries of the electron beam caused by the bends that are used to inject electrons into the interaction region and to extract them. A distribution of electron macroparticles is deposited on a discrete grid enclosed in a conducting pipe. The electrostatic potential and electric fields are calculated using numerical Poisson solvers. The kicks experienced by the circulating beam are estimated by integrating the electric fields over straight trajectories. These kicks are also provided in the form of interpolated analytical symplectic maps for numerical tracking simulations, which are needed to estimate the effects of the electron lens imperfections on proton lifetimes, emittance growth, and dynamic aperture. We outline a general procedure to calculate the magnitude of the transverse proton kicks, which can then be generalized, if needed, to include further refinements such as the space-charge evolution of the electron beam, magnetic fields generated by the electron current, and longitudinal proton dynamics.

  16. Analytic Models of Plausible Gravitational Lens Potentials

    Energy Technology Data Exchange (ETDEWEB)

    Baltz, Edward A.; Marshall, Phil; Oguri, Masamune

    2007-05-04

    Gravitational lenses on galaxy scales are plausibly modeled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sersic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasizing that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential.We also provide analytic formulae for the lens potentials of Sersic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modeled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses.

  17. CHINA'S WORST OIL LEAK CLEARED EXPENSIVELY

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Eight days and nights of clean-up efforts after the worst oil leak ever in Chinese waters, the aftermath of a collision between two foreign ships happening at 9:35 pm on December 7 about 8 nautical miles away from the mouth of the Pearl River and near the Danjiang Island, have finally paid off. So far, hundreds of tons of waste oil and polluted water have been cleared up. A large area of oil spills has been cleaned thanks to the prompt and proper operation launched just two hours after the accident.

  18. A gap clearing kicker for Main Injector

    CERN Document Server

    Kourbanis, I; Biggs, J; Brown, B; Capista, D; Jensen, C C; Krafczyk, G E; Morris, D K; Scott, D; Seiya, K; Ward, S R; Wu, G; Yang, M -J

    2012-01-01

    Fermilab Main Injector has been operating at high Beam Power levels since 2008 when multi-batch slip stacking became operational. In order to maintain and increase the beam power levels the localized beam loss due to beam left over in the injection kicker gap during slip stacking needs to be addressed. A set of gap clearing kickers that kick any beam left in the injection gap to the beam abort have been built. The kickers were installed in the summer of 2009 and became operational in November of 2010. The kicker performance and its effect on the beam losses will be described.

  19. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    Directory of Open Access Journals (Sweden)

    Elena Bonafonte Marquez

    2015-01-01

    Full Text Available We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for it could be the only sign of secondary glaucoma.

  20. Fundamentals of concentric lens systems synthesis

    Science.gov (United States)

    Ezhova, Kseniia; Zverev, Victor; Tochilina, Tatiana; Tymoshchuk, Irina

    2016-09-01

    Introduction of coefficients defining the relationship of the radii of curvature of the surfaces of concentric optical systems, allowed the transformation of the obtained analytical relations in a system of two equations with two unknowns. It is shown that the existence of the solution of the system of equations determined by the optical constants of the selected lens material. The results of the analysis of the conditions of the chromatic aberration correction position and the sequence of obtaining of the system equations define the theoretical basis of the engineering method of parametric synthesis of concentric lens systems. Application of the developed method is illustrated by examples of calculation particular systems design build.

  1. Time resolved thermal lens in edible oils

    Science.gov (United States)

    Albuquerque, T. A. S.; Pedreira, P. R. B.; Medina, A. N.; Pereira, J. R. D.; Bento, A. C.; Baesso, M. L.

    2003-01-01

    In this work time resolved thermal lens spectrometry is applied to investigate the optical properties of the following edible oils: soya, sunflower, canola, and corn oils. The experiments were performed at room temperature using the mode mismatched thermal lens configuration. The results showed that when the time resolved procedure is adopted the technique can be applied to investigate the photosensitivity of edible oils. Soya oil presented a stronger photochemical reaction as compared to the other investigated samples. This observation may be relevant for future studies evaluating edible oils storage conditions and also may contribute to a better understanding of the physical and chemical properties of this important foodstuff.

  2. Pulse transformer for the AA lithium lens

    CERN Multimedia

    1980-01-01

    The antiprotons emanating from the target were initially focused by a magnetic horn. Later on, a Li-lens was used during operation for the SPS collider, until 1992. A Li-rod (130 mm long, 34 mm in diameter) constituted the secondary of a 1:23 pulse-transformer. The half-sine pulse rose to 1000 kA in 900 microsec. The angular acceptance was 95 mrad. In operation after 1992, for LEAR only, a more modest Li-lens was used (155 mm long, diameter 20 mm, 480 kA, risetime 240 microsec, angular acceptance 75 mrad).

  3. Experimental Contact Lens to Prevent Glaucoma-Induced Blindness

    Science.gov (United States)

    ... Home Page An Experimental Contact Lens to Prevent Glaucoma-Induced Blindness By Sharon Reynolds Posted January 23, 2014 An experimental contact lens design releases a glaucoma medicine at a steady rate for up to ...

  4. Malignant Clear Cell Hidradenoma of the Breast

    Science.gov (United States)

    Rahal, Ahmad K.; Reddy, Pavan S; Kallail, K. James

    2017-01-01

    A 58-year-old female had a mass in the right breast palpable beneath the areola. A mammogram revealed a 1.5-centimeter soft tissue density that was confirmed with a subsequent ultrasound. The patient underwent a core needle biopsy which was initially reported as a moderately differentiated invasive ductal carcinoma. Immunohistochemical analysis revealed negative staining for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER2), mammaglobin, and gross cystic disease fluid protein 15 (GCDFP-15). A wide local excision of the mass was performed. The pathology report stated the tumor had an infiltrative growth pattern with a desmoplastic stromal response with enhanced epithelial atypia consistent with malignant transformation of a nodular clear cell hidradenoma. Clear cell hidradenoma is a very rare tumor originating from the sweat gland and has a propensity for the face and extremities. The malignant variant of this tumor is extremely rare and has been reported to originate from the breast in few cases. This case represents the difficulty in diagnosing this tumor along with the radiographic and histologic features that can distinguish this malignancy from other entities.

  5. Comparative properties of optically clear epoxy encapsulants

    Science.gov (United States)

    Edwards, Maury; Zhou, Yan

    2001-12-01

    Three epoxy systems were evaluated for physical dn optical properties. The three systems chosen for the study were selected on the basis of their optical clarity, color and chemistry. Three distinctly different chemistries were chosen, aromatic epoxy-amine cured. Aromatic epoxy- anhydride cured and cycloaliphatic epoxy-anhydride cured. All three systems remained optically clear and water-white after full cure. The three selected systems were tested for physical properties, adhesion and light transmission properties. Light transmission was measured after thermal and humidity exposure. Adhesion was measured after humidity exposure only. Both of the epoxy-anhydride systems performed well in optical properties but poorer in adhesion as compared to the epoxy-amine system. The aromatic epoxy- amine system discolored badly during thermal exposure at 100 C. Data generated from this work will be used in selecting clear encapsulating materials for photonics applications. No single system offers optimal performance in all areas. The best compromise material is the aromatic epoxy-anhydride system.

  6. An Ultrasonic Lens Design Based on Prefractal Structures

    OpenAIRE

    Sergio Castiñeira-Ibáñez; Daniel Tarrazó-Serrano; Constanza Rubio; Pilar Candelas; Antonio Uris

    2016-01-01

    The improvement in focusing capabilities of a set of annular scatterers arranged in a fractal geometry is theoretically quantified in this work by means of the finite element method (FEM). Two different arrangements of rigid rings in water are used in the analysis. Thus, both a Fresnel ultrasonic lens and an arrangement of rigid rings based on Cantor prefractals are analyzed. Results show that the focusing capacity of the modified fractal lens is better than the Fresnel lens. This new lens is...

  7. Lens autofluorescence is not increased at high altitude

    DEFF Research Database (Denmark)

    Kessel, Line; Kofoed, Peter Kristian; Zubieta-Calleja, Gustavo;

    2010-01-01

    PURPOSE: To study the relation between ambient environmental ultraviolet radiation exposure and lens fluorescence. METHODS: Non-invasive lens fluorometry measurements were compared in healthy Bolivian and Danish subjects. Background ultraviolet radiation was 4.5 times higher in Bolivia than...... living at sea level at 55 degrees northern latitude. These results suggest that lens ageing, as assessed by lens autofluorometry, is independent of exposure to ultraviolet radiation....

  8. 21 CFR 886.4300 - Intraocular lens guide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraocular lens guide. 886.4300 Section 886.4300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device...

  9. 21 CFR 886.5916 - Rigid gas permeable contact lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens. 886.5916 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5916 Rigid gas permeable contact lens. (a) Identification. A rigid gas permeable contact lens is a device intended to be worn...

  10. 21 CFR 800.10 - Contact lens solutions; sterility.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contact lens solutions; sterility. 800.10 Section...) MEDICAL DEVICES GENERAL Requirements for Specific Medical Devices § 800.10 Contact lens solutions... ophthalmic use, including contact lens solutions, should be sterile. It is further evident that...

  11. An unusual case of clear cell meningioma

    Directory of Open Access Journals (Sweden)

    Deb Prabal

    2009-01-01

    Full Text Available Clear-cell meningioma (CCM is an uncommon, aggressive variant of meningioma, usually affecting younger females and having predilection for infratentorial locations. We present a rare case of recurrent supratentorial CCM in a 58-year-old male. Ten years back, he had an intra-axial tumor in the left occipital lobe, which was managed by surgical excision and radiotherapy. Currently, the patient presented with sudden severe headache along with speech and vision disturbances. Neuroimaging revealed an extra-axial parietooccipital tumor, with intratumoural bleed. Histopathology of both tumors showed features of CCM, immunopositive for epithelial membrane antigen (EMA and vimentin. This case illustrates multiple unusual features of a rare variant of meningioma in the form of affection of an adult age group, supratentorial location, recurrence, and intratumoral bleed. It also highlights the importance of incorporating immunohistochemistry in the diagnostic workup, to exclude CCM mimics, each having distinctive biological behavior, and prognostic outcome, and warranting different therapeutic protocols.

  12. SHARP - III: First Use Of Adaptive Optics Imaging To Constrain Cosmology With Gravitational Lens Time Delays

    CERN Document Server

    Chen, Geoff C F; Wong, Kenneth C; Fassnacht, Christopher D; Chiueh, Tzihong; Halkola, Aleksi; Hu, I Shing; Auger, Matthew W; Koopmans, Leon V E; Lagattuta, David J; McKean, John P; Vegetti, Simona

    2016-01-01

    Accurate and precise measurements of the Hubble constant are critical for testing our current standard cosmological model and revealing possibly new physics. With Hubble Space Telescope (HST) imaging, each strong gravitational lens system with measured time delays can allow one to determine the Hubble constant with an uncertainty of $\\sim 7\\%$. Since HST will not last forever, we explore adaptive-optics (AO) imaging as an alternative that can provide higher angular resolution than HST imaging but has a less stable point spread function (PSF) due to atmospheric distortion. To make AO imaging useful for time-delay-lens cosmography, we develop a method to extract the unknown PSF directly from the imaging of strongly lensed quasars. In a blind test with two mock data sets created with different PSFs, we are able to recover the important cosmological parameters (time-delay distance, external shear, lens mass profile slope, and total Einstein radius). Our analysis of the Keck AO image of the strong lens system RXJ1...

  13. Solar powered desalination system using Fresnel lens

    Science.gov (United States)

    Sales, M. T. B. F.

    2016-11-01

    The Philippines is surrounded by coastal areas and these areas can be a potential source for potable water. This study aims to design and construct a solar powered desalination system using Fresnel lens. The experimental study was conducted using polluted salt water for the sample and desalination was carried out using the designed system. The desalination system was composed of the solar concentrator, solar still and the condenser system. The Fresnel lens was made of acrylic plastic and was an effective solar concentrator. Solar stills made of dark colored glass bottles were effective in absorbing the solar energy. The condenser system made of polybutylene and polystyrene were effective in condensing the vapor at ambient temperature. The shortest time of vaporization of the salt water was at 293 sec and the optimum angle of position of the lens was 36.42°. The amount of condensate collected was directly proportional to the amount of salt water in the solar still. The highest mean efficiency of the designed set-up was 34.82%. The water produced by the solar powered desalination system using Fresnel lens passed the standards set by WHO (World Health Organization) for drinking water.

  14. Intraocular lens in a fighter aircraft pilot.

    OpenAIRE

    Loewenstein, A; Geyer, O; Biger, Y; Bracha, R; Shochat, I; Lazar, M.

    1991-01-01

    A pseudophakic pilot of the Israeli air force flying an F-15 (Eagle) aircraft was followed up for three years. He experienced about 100 flying hours, 5% of the time under high g stress. The intraocular lens did not dislocate and no complications were observed. It seems that flying high performance fighter aircraft is not contraindicated in pseudophakic pilots.

  15. Contact lens wear and microbial keratitis.

    Science.gov (United States)

    Ahuja, Markanday

    2002-11-01

    Common types of contact lens are hard, rigid gas-permeable or soft lenses. Most lenses are worn on a daily basis. Cosmetic lenses are worn for non-medical indications. Microbial keratitis, a rare but most significant complication is discussed in this article. Pseudomonas aeruginosa and staphylococci are the most common organisms cause infective keratitis. Fungi and acanthamoeba are also responsible. The causes of increased susceptibility to infection are poor lens hygiene, adhesion of bacteria to lens surface and hypoxia. Preventing measures to be taken while wearing contact lens are discussed in a nutshell. Ocular pain, conjunctival infection, photophobia, epiphora and reduced vision are some of the symptoms of corneal infection. Diagnostic laboratory investigations are to be carried out immediately when a microbial corneal ulcer is suspected. Acanthamoeba can be cultured from corneal scrapes. Immunologically based fluorescein labelling techniques appear to be more sensitive than simple staining. The treatment consists of medical and surgical intervention. Corneal thinning, descemetocele formation and perforation are possible complications.

  16. Contact lens rehabilitation following repaired corneal perforations

    Directory of Open Access Journals (Sweden)

    Sreenivas V

    2006-03-01

    Full Text Available Abstract Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60% required aphakic contact lenses. The best corrected visual acuity (BCVA of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25% eyes with spectacle correction and 37 (92.5% eyes with the use of contact lens (p Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries.

  17. Magnifying perfect lens with positive refraction

    CERN Document Server

    Tyc, Tomas

    2010-01-01

    We propose a device with a positive isotropic refractive index that creates a magnified perfect real image of an optically homogeneous three-dimensional region of space within geometrical optics. Its key ingredient is a new refractive index profile that can work as a perfect lens on its own, having a very moderate index range.

  18. High Accuracy Dual Lens Transmittance Measurements

    Science.gov (United States)

    2007-08-01

    measurement of lens transmission,” Metrologia 37, 603–605 (2000). 3. B. Munro, “Quantum information processing with light and its requirement for detectors...5. N. P. Fox, “Trap detectors and their properties,” Metrologia 28, 197–202 (1991). 5402 APPLIED OPTICS Vol. 46, No. 22 1 August 2007 6. S. L

  19. Testing and inspecting lens by holographic means

    Science.gov (United States)

    Hildebrand, Bernard P.

    1976-01-01

    Processes for the accurate, rapid and inexpensive testing and inspecting of oncave and convex lens surfaces through holographic means requiring no beamsplitters, mirrors or overpower optics, and wherein a hologram formed in accordance with one aspect of the invention contains the entire interferometer and serves as both a master and illuminating source for both concave and said convex surfaces to be so tested.

  20. Lens testing using total internal reflection holography

    Science.gov (United States)

    Hildebrand, Bernard P.

    1976-12-14

    Accurate, rapid and inexpensive testing and inspecting of lens surfaces tugh holographic means requiring no beamsplitters, mirrors or overpower optics, and wherein a hologram formed in accordance with one aspect of the invention contains the entire interferometer and serves as both a master and illuminating source for both concave and convex surfaces to be so tested.

  1. Application of optical polymers in lens design

    Science.gov (United States)

    Sultanova, Nina; Kasarova, Stefka; Nikolov, Ivan

    2016-03-01

    Optical, some thermal and elastic properties of optical polymers which are of importance in lens design are considered. Results are based on precise measurement of refraction of materials. Ultrasonic investigation of elastic moduli is carried out. Comparison to properties of Schott glasses is accomplished. Examples on the design of all-plastic and hybrid glass-plastic systems are presented.

  2. High Dk piggyback contact lens system for contact lens-intolerant keratoconus patients

    OpenAIRE

    Tomris Sengor; Sevda Aydin Kurna; Suat Aki; et al

    2011-01-01

    Tomris Sengor, Sevda Aydin Kurna, Suat Aki, Yelda ÖzkurtFatih Sultan Mehmet Training and Research Hospital, Istanbul, TurkeyBackground: The aim of the study was to examine the clinical success of high Dk (oxygen permeability) piggyback contact lens (PBCL) systems for the correction of contact lens intolerant keratoconus patients.Methods: Sixteen patients (29 eyes) who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen tran...

  3. Analysis of fiber lens with gradient index based on thin lens equivalence

    Institute of Scientific and Technical Information of China (English)

    ZHANG Rui-feng; GE Chun-feng; LI Shi-chen

    2006-01-01

    Theoretical analysis of the fiber-lens TEC (Thermally Expended Core) /Coreless/GRIN (Graded-Index) based on thin lens equivalence is presented in this paper.On condition that the TEC part adjusts the waist radius of an incident Gaussian beam,that the coreless part controlls the space between the beam waist and the thin lens,and that the GRIN part acts as the thin lens with its focal length determined by fiber index distribution parameter g,the analytic expressions of the waist spot size and the working distance of the output Gaussian beam are derived,and the influence of the coreless fiber and the length of the GRIN fiber upon the fiber-lens parameter is discussed based on the numerical simulation results.It is concluded that,if a GRIN style fiber-lens is used as a collimator,the maximum of the spot waist can be up to 80 μm and the divergence angle of single-mode optical fiber can be reduced by 8 times.If it is applied to a MEMS device, the maximum working distance can be up to 3 mm.

  4. Automatic detection of cortical and PSC cataracts using texture and intensity analysis on retro-illumination lens images.

    Science.gov (United States)

    Chow, Yew Chung; Gao, Xinting; Li, Huiqi; Lim, Joo Hwee; Sun, Ying; Wong, Tien Yin

    2011-01-01

    Cataract remains a leading cause for blindness worldwide. Cataract diagnosis via human grading is subjective and time-consuming. Several methods of automatic grading are currently available, but each of them suffers from some drawbacks. In this paper, a new approach for automatic detection based on texture and intensity analysis is proposed to address the problems of existing methods and improve the performance from three aspects, namely ROI detection, lens mask generation and opacity detection. In the detection method, image clipping and texture analysis are applied to overcome the over-detection problem for clear lens images and global thresholding is exploited to solve the under-detection problem for severe cataract images. The proposed method is tested on 725 retro-illumination lens images randomly selected from a database of a community study. Experiments show improved performance compared with the state-of-the-art method.

  5. Gram negative bacteria and contact lens induced acute red eye

    Directory of Open Access Journals (Sweden)

    Sankaridurg Padmaja

    1996-01-01

    Full Text Available Two patients using hydrogel contact lenses on a daily wear schedule slept overnight with the lenses and woke up with a Contact Lens Induced Acute Red Eye (CLARE. The contact lenses recovered aseptically at the time of the event grew significant colonies of Pseudomonas aeruginosa and Aeromonas hydrophila in patient A and Pseudomonas aeruginosa and Serratia liquefaciens from patient B. Similar organisams from the contact lenses were recovered from the lens case and lens care solutions of patient B. In both the patients the condition resolved on discontinuation of lens wear. Patient compliance as a requirement for successful contact lens wear is highlighted with the illustration of these cases.

  6. Liquid bridge as a tunable-focus cylindrical liquid lens

    Science.gov (United States)

    Chen, H.; Tabatabaei, N.; Amirfazli, A.

    2017-01-01

    We proposed a method to create a tunable-focus cylindrical liquid lens using a liquid bridge between two narrow surfaces. Due to the surface edge effect, the interface of the liquid bridge (on the long side) was shown to be able to serve as a tunable-focus cylindrical liquid lens. The working distance of the lens can be adjusted by changing either or both of the height of the bridge (H) and the volume of the liquid (V). By varying H and V, the lens can serve as either diverging or converging lens, with a minimum working distance of 2.11 mm.

  7. Acid phosphatase and lipid peroxidation in human cataractous lens epithelium

    Directory of Open Access Journals (Sweden)

    Vasavada Abhay

    1993-01-01

    Full Text Available The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium. In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium. From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

  8. Hypoplastic basement membrane of the lens anlage in the inheritable lens aplastic mouse (lap mouse).

    Science.gov (United States)

    Aso, S; Baba, R; Noda, S; Ikuno, S; Fujita, M

    2000-04-01

    Adult homozygous lap mice show various eye abnormalities such as aphakia, retinal disorganization, and dysplasia of the cornea and anterior chamber. In the fetal eye of a homozygous lap mouse, the lens placode appears to develop normally. However, the lens vesicle develops abnormally to form a mass of cells without a cavity, and the mass vanishes soon afterward. Apoptotic cell death is associated with the disappearance of the lens anlage. We examined the basement membranes of the lens anlage of this mutant by immunohistochemical methods under light microscopy using antibodies against basement membrane components of the lens anlage, type IV collagen, fibronectin, laminin, heparan sulfate proteoglycan, and entactin and by transmission electron microscopy. Immunohistochemistry showed the distribution and intensity of antibody binding to the lens anlage to be almost the same for each these antibodies regardless of the stage of gestation or whether the anlagen were from normal BALB/c or lap mice. Thus, positive continuous reactions were observed around the exterior region of the lens anlage from day 10 of gestation for type IV collagen, fibronectin, laminin, heparan sulfate proteoglycan antibodies, and at least from day 11of gestation for entactin antibody. The basement membrane lamina densa of both normal and lap mice was shown by electron microscopy to be discontinuous at days 10 and 10.5 of gestation. However, by day 11 the lamina densa was continuous in the lens anlagen of normal mice but still discontinuous in the lap mice. By day 12 of gestation, the lamina densa had thickened markedly in normal mice, whereas in lap mice it remained discontinuous and its thinness indicated hypoplasia. These results indicate that, while all basement components examined are produced and deposited in the normal region of the lens anlage in the lap mouse, the basement membrane is, for some reason, imperfectly formed. The time at which hypoplasia of the basement membrane was observed

  9. Method and apparatus for sputtering with a plasma lens

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2016-09-27

    A plasma lens for enhancing the quality and rate of sputter deposition onto a substrate is described herein. The plasma lens serves to focus positively charged ions onto the substrate while deflecting negatively charged ions, while at the same time due to the line of sight positioning of the lens, allowing for free passage of neutrals from the target to the substrate. The lens itself is formed of a wound coil of multiple turns, inside of which are deposed spaced lens electrodes which are electrically paired to impress an E field overtop the B field generated by the coil, the potential applied to the electrodes increasing from end to end towards the center of the lens, where the applied voltage is set to a high potential at the center electrodes as to produce a potential minimum on the axis of the lens.

  10. Lightweight autoclavable wide-angle contact lens for vitreous surgery.

    Science.gov (United States)

    Chalam, K V; Gupta, Shailesh K; Agarwal, Swati

    2007-01-01

    The authors describe an autoclavable, self-stabilizing, lightweight wide-angle contact lens for vitrectomy. The lens has two optical pieces with perforated plastic casing to sustain a high temperature (150 degrees C) for autoclaving. The lens has a 106 degrees static and 127 degrees dynamic field of view. The footplates and reduced weight (2.4 grams) due to the plastic casing allow self-stabilization of the lens. The open lens design.with high temperature resistant plastic prevents fogging during autoclaving and surgery. The autoclavable, self-stabilizing, lightweight wide-angle contact lens allows visualization of the peripheral retina during surgery and faster sterilization by autoclaving between surgeries without the disadvantage of lens fogging.

  11. An Electromagnetic Sensor with a Metamaterial Lens for Nondestructive Evaluation of Composite Materials

    Directory of Open Access Journals (Sweden)

    Adriana Savin

    2015-07-01

    Full Text Available This paper proposes the study and implementation of a sensor with a metamaterial (MM lens in electromagnetic nondestructive evaluation (eNDE. Thus, the use of a new type of MM, named Conical Swiss Rolls (CSR has been proposed. These structures can serve as electromagnetic flux concentrators in the radiofrequency range. As a direct application, plates of composite materials with carbon fibers woven as reinforcement and polyphenylene sulphide as matrix with delaminations due to low energy impacts were examined. The evaluation method is based on the appearance of evanescent modes in the space between carbon fibers when the sample is excited with a transversal magnetic along z axis (TMz polarized electromagnetic field. The MM lens allows the transmission and intensification of evanescent waves. The characteristics of carbon fibers woven structure became visible and delaminations are clearly emphasized. The flaws can be localized with spatial resolution better than λ/2000.

  12. An Electromagnetic Sensor with a Metamaterial Lens for Nondestructive Evaluation of Composite Materials.

    Science.gov (United States)

    Savin, Adriana; Steigmann, Rozina; Bruma, Alina; Šturm, Roman

    2015-07-03

    This paper proposes the study and implementation of a sensor with a metamaterial (MM) lens in electromagnetic nondestructive evaluation (eNDE). Thus, the use of a new type of MM, named Conical Swiss Rolls (CSR) has been proposed. These structures can serve as electromagnetic flux concentrators in the radiofrequency range. As a direct application, plates of composite materials with carbon fibers woven as reinforcement and polyphenylene sulphide as matrix with delaminations due to low energy impacts were examined. The evaluation method is based on the appearance of evanescent modes in the space between carbon fibers when the sample is excited with a transversal magnetic along z axis (TMz) polarized electromagnetic field. The MM lens allows the transmission and intensification of evanescent waves. The characteristics of carbon fibers woven structure became visible and delaminations are clearly emphasized. The flaws can be localized with spatial resolution better than λ/2000.

  13. Clear Channel Assessment in Integrated Medical Environments

    Directory of Open Access Journals (Sweden)

    Bin Zhen

    2008-03-01

    Full Text Available Complementary WLAN and WPAN technologies as well as other wireless technologies will play a fundamental role in the medical environments to support ubiquitous healthcare delivery. This paper investigates clear channel assessment (CCA and its impact on the coexistence of WLAN (IEEE 802.11 high rate direct sequence spread spectrum (HR/DSSS PHY and WPAN (IEEE 802.15.4b in the 2.4 GHz industrial, scientific, and medical (ISM band. We derived closed-form expressions of both energy-based CCA and feature-based CCA. We qualified unequal sensing abilities between them and termed this inequality asymmetric CCA, which is different from the traditional “hidden node” or “exposed node” issues in the homogeneous network. The energy-based CCA was considered in the considered integrated medical environment because the 2.4 GHz ISM band is too crowded to apply feature-based CCA. The WPAN is oversensitive to the 802.11 HR/DSSS signals and the WLAN is insensitive to the 802.15.4b signals. Choosing an optimal CCA threshold requires some prior knowledge of the underlying signals. In the integrated medical environment we considered here, energy-based CCA can effectively avoid possible packet collisions when they are close within the “heterogeneous exclusive CCA range” (HECR. However, when they are separated beyond the HECR, WPAN can still sense the 802.11 HR/DSSS signals, but WLAN loses its sense to the 802.15.4b signals. The asymmetric CCA leads to WPAN traffic in a position secondary to WLAN traffic.

  14. Clear Channel Assessment in Integrated Medical Environments

    Directory of Open Access Journals (Sweden)

    Hara Shinsuke

    2008-01-01

    Full Text Available Abstract Complementary WLAN and WPAN technologies as well as other wireless technologies will play a fundamental role in the medical environments to support ubiquitous healthcare delivery. This paper investigates clear channel assessment (CCA and its impact on the coexistence of WLAN (IEEE 802.11 high rate direct sequence spread spectrum (HR/DSSS PHY and WPAN (IEEE 802.15.4b in the 2.4 GHz industrial, scientific, and medical (ISM band. We derived closed-form expressions of both energy-based CCA and feature-based CCA. We qualified unequal sensing abilities between them and termed this inequality asymmetric CCA, which is different from the traditional "hidden node" or "exposed node" issues in the homogeneous network. The energy-based CCA was considered in the considered integrated medical environment because the 2.4 GHz ISM band is too crowded to apply feature-based CCA. The WPAN is oversensitive to the 802.11 HR/DSSS signals and the WLAN is insensitive to the 802.15.4b signals. Choosing an optimal CCA threshold requires some prior knowledge of the underlying signals. In the integrated medical environment we considered here, energy-based CCA can effectively avoid possible packet collisions when they are close within the "heterogeneous exclusive CCA range" (HECR. However, when they are separated beyond the HECR, WPAN can still sense the 802.11 HR/DSSS signals, but WLAN loses its sense to the 802.15.4b signals. The asymmetric CCA leads to WPAN traffic in a position secondary to WLAN traffic.

  15. Ultrashort-Pulse Lasers Treating the Crystalline Lens: Will They Cause Vision-Threatening Cataract? (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Krueger, Ronald R.; Uy, Harvey; McDonald, Jared; Edwards, Keith

    2012-01-01

    Purpose: To demonstrate that ultrashort-pulse laser treatment in the crystalline lens does not form a focal, progressive, or vision-threatening cataract. Methods: An Nd:vanadate picosecond laser (10 ps) with prototype delivery system was used. Primates: 11 rhesus monkey eyes were prospectively treated at the University of Wisconsin (energy 25–45 μJ/pulse and 2.0–11.3M pulses per lens). Analysis of lens clarity and fundus imaging was assessed postoperatively for up to 4½ years (5 eyes). Humans: 80 presbyopic patients were prospectively treated in one eye at the Asian Eye Institute in the Philippines (energy 10 μJ/pulse and 0.45–1.45M pulses per lens). Analysis of lens clarity, best-corrected visual acuity, and subjective symptoms was performed at 1 month, prior to elective lens extraction. Results: Bubbles were immediately seen, with resolution within the first 24 to 48 hours. Afterwards, the laser pattern could be seen with faint, noncoalescing, pinpoint micro-opacities in both primate and human eyes. In primates, long-term follow-up at 4½ years showed no focal or progressive cataract, except in 2 eyes with preexisting cataract. In humans, 70% reported acceptable or better distance vision and no or mild symptoms. Meanwhile, >70% without sparing (0 and 0.5 mm radius) lost 2 or more lines, and most reported poor or severe vision and symptoms. Conclusions: Focal, progressive, and vision-threatening cataracts can be avoided by lowering the laser energy, avoiding prior cataract, and sparing the center of the lens. PMID:23818739

  16. Hyaluronic acid production and hyaluronidase activity in the newt iris during lens regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Kulyk, W.M.; Zalik, S.E.; Dimitrov, E.

    1987-09-01

    The process of lens regeneration in newts involves the dedifferentiation of pigmented iris epithelial cells and their subsequent conversion into lens fibers. In vivo this cell-type conversion is restricted to the dorsal region of the iris. We have examined the patterns of hyaluronate accumulation and endogenous hyaluronidase activity in the newt iris during the course of lens regeneration in vivo. Accumulation of newly synthesized hyaluronate was estimated from the uptake of (/sup 3/H)glucosamine into cetylpyridinium chloride-precipitable material that was sensitive to Streptomyces hyaluronidase. Endogenous hyaluronidase activity was determined from the quantity of reducing N-acetylhexosamine released upon incubation of iris tissue extract with exogenous hyaluronate substrate. We found that incorporation of label into hyaluronate was consistently higher in the regeneration-activated irises of lentectomized eyes than in control irises from sham-operated eyes. Hyaluronate labeling was higher in the dorsal (lens-forming) region of the iris than in ventral (non-lens-forming) iris tissue during the regeneration process. Label accumulation into hyaluronate was maximum between 10 and 15 days after lentectomy, the period of most pronounced dedifferentiation in the dorsal iris epithelium. Both normal and regenerating irises demonstrated a high level of endogenous hyaluronidase activity with a pH optimum of 3.5-4.0. Hyaluronidase activity was 1.7 to 2 times higher in dorsal iris tissue than in ventral irises both prior to lentectomy and throughout the regeneration process. We suggest that enhanced hyaluronate accumulation may facilitate the dedifferentiation of iris epithelial cells in the dorsal iris and prevent precocious withdrawal from the cell cycle. The high level of hyaluronidase activity in the dorsal iris may promote the turnover and remodeling of extracellular matrix components required for cell-type conversion.

  17. Vitreoretinal Surgery for Intraocular Lens Dislocated into the Vitreous Cavity

    Directory of Open Access Journals (Sweden)

    Dilek Özçelik Soba

    2015-04-01

    Full Text Available Objectives: To investigate the sex, age, accompanying eye examination findings, and the outcomes of vitreoretinal surgery (VRS for intraocular lens (IOL dislocated into the vitreous cavity. Materials and Methods: The medical records of 30 patients who underwent VRS for IOL dislocation into the vitreous cavity were retrospectively analyzed in this study. Preoperative and postoperative visual acuity, intraocular pressure, biomicroscopic, and posterior segment examination findings were assessed. Results: The average age of the patients was 63.1 (range: 38-83 years. Twenty-one patients were male (70% and 9 patients were female (30%. As etiologic causes, 18 cases (60% had late spontaneous dislocation, 5 cases (16.6% had dislocation after phacoemulsification surgery, 4 cases (13.3% had trauma, 2 cases (6.6% had previously undergone vitrectomy, and 1 case (3.3% had undergone YAG laser capsulotomy. VRS including 23-gauge triamcinolone-assisted pars plana vitrectomy, intraocular lens extraction, posterior hyaloid membrane removing, endolaser photocoagulation, and fluid-air exchange was performed. Posterior chamber IOL implantation on to the anterior capsule in 13 cases (43.3%, anterior chamber IOL implantation in 10 cases (33.3%, and scleral fixated posterior IOL implantation in 4 cases (13.3% were performed. The corrected visual acuity recorded at the last follow-up was better than the first visit in 23 cases (76.6%, the same in 5 eyes (16.6%, and worse in 2 eyes (6.6%. Conclusion: VRS combined IOL implantation is a successful surgery method for IOL dislocated into the vitreous cavity and can avoid poor visual outcomes. (Turk J Ophthalmol 2015; 45: 56-9

  18. When a Cleared Rape Is Not Cleared: A Multilevel Study of Arrest and Exceptional Clearance.

    Science.gov (United States)

    Walfield, Scott M

    2016-05-01

    As rape remains one of the most underreported and least likely to be cleared of the violent crimes, it is of paramount importance to understand the factors associated with the likelihood of a case being cleared by law enforcement. This study uses data from the National Incident-Based Reporting System (NIBRS) and the Law Enforcement Management and Administrative Statistics (LEMAS), and a multilevel modeling approach to examine the relationship between victim, offender, incident, and police department characteristics contrasting the two types of clearance: arrest and exceptional clearance. The latter occurs due to reasons outside of law enforcement's control and despite being considered cleared, the offender is not arrested, charged, nor turned over for prosecution. Of the 16,231 cleared rapes in 238 departments, nearly half (47%) results in exceptional clearance when the victim refuses to cooperate or when prosecution is declined. Incident-level variables have a greater effect on the likelihood of exceptional clearance than victim and offender variables. The department explained a nontrivial amount of variation in the dependent variable, as 37% of the variance in type of clearance was between-department variation. Implications for future research on exceptional clearance and NIBRS are discussed.

  19. MODIS Collection 6 Clear Sky Restoral (CSR): Filtering Cloud Mast 'Not Clear' Pixels

    Science.gov (United States)

    Meyer, Kerry G.; Platnick, Steven Edward; Wind, Galina; Riedi, Jerome

    2014-01-01

    Correctly identifying cloudy pixels appropriate for the MOD06 cloud optical and microphysical property retrievals is accomplished in large part using results from the MOD35 1km cloud mask tests (note there are also two 250m subpixel cloud mask tests that can convert the 1km cloudy designations to clear sky). However, because MOD35 is by design clear sky conservative (i.e., it identifies "not clear" pixels), certain situations exist in which pixels identified by MOD35 as "cloudy" are nevertheless likely to be poor retrieval candidates. For instance, near the edge of clouds or within broken cloud fields, a given 1km MODIS field of view (FOV) may in fact only be partially cloudy. This can be problematic for the MOD06 retrievals because in these cases the assumptions of a completely overcast homogenous cloudy FOV and 1-dimensional plane-parallel radiative transfer no longer hold, and subsequent retrievals will be of low confidence. Furthermore, some pixels may be identified by MOD35 as "cloudy" for reasons other than the presence of clouds, such as scenes with thick smoke or lofted dust, and should therefore not be retrieved as clouds. With such situations in mind, a Clear Sky Restoral (CSR) algorithm was introduced in C5 that attempts to identify pixels expected to be poor retrieval candidates. Table 1 provides SDS locations for CSR and partly cloudy (PCL) pixels.

  20. Clear cell renal cell tumors: Not all that is "clear" is cancer.

    Science.gov (United States)

    Williamson, Sean R; Cheng, Liang

    2016-07-01

    Continued improvement of our understanding of the clinical, histologic, and genetic features of renal cell tumors has progressively evolved renal tumor classification, revealing an expanding array of distinct tumor types with different implications for prognosis, patient counseling, and treatment. Although clear cell renal cell carcinoma is unequivocally the most common adult renal tumor, there is growing evidence that some "clear cell" renal neoplasms, such as exemplified by multilocular cystic clear cell renal neoplasm of low malignant potential (formerly multilocular cystic renal cell carcinoma), do not have the same potential for insidious progression and metastasis, warranting reclassification as low malignant potential tumors or benign neoplasms. Still other novel tumor types such as clear cell papillary renal cell carcinoma have been more recently recognized, which similarly have shown a conspicuous absence of aggressive behavior to date, suggesting that these too may be recategorized as noncancerous or may be premalignant neoplasms. This importance for prognosis is increasingly significant in the modern era, in which renal masses are increasingly found incidentally by imaging techniques at a small tumor size, raising consideration for less aggressive management options guided by renal mass biopsy diagnosis, including imaging surveillance, tumor ablation, or partial nephrectomy.

  1. GA(2)LEN skin test study I: GA(2)LEN harmonization of skin prick testing: novel sensitization patterns for inhalant allergens in Europe

    DEFF Research Database (Denmark)

    Heinzerling, L M; Burbach, G J; Edenharter, G

    2009-01-01

    BACKGROUND: Skin prick testing is the standard for diagnosing IgE-mediated allergies. However, different allergen extracts and different testing procedures have been applied by European allergy centres. Thus, it has been difficult to compare results from different centres or studies across Europe....... It was, therefore, crucial to standardize and harmonize procedures in allergy diagnosis and treatment within Europe. AIMS: The Global Asthma and Allergy European Network (GA(2)LEN), with partners and collaborating centres across Europe, was in a unique position to take on this task. The current study...

  2. Experimental study on cyclosporine A drug delivery system in prevention of posterior capsule opacification after intraocular lens implantation in rabbits

    Institute of Scientific and Technical Information of China (English)

    Pei Cheng; Sun Naixue

    2008-01-01

    Objective To study the effect of cyclosporine A drug delivery system (CsA-DDS) on the prevention of posterior capsule opacification (PCO) after experimental intraocular lens implantation in rabbit eyes. Methods Twenty healthy New Zealand white rabbits, whose left eyes and right eyes were used respectively as experiment eyes and controls, were subjected to extracapsular lens extraction and artificial lens implantation. During the operation, CsA-DDS with poly (lactideco-glycolide) as carriers or empty DDS was implanted in the capsular bag for the experimental eyes and controls respectively. After the operation, anterior chamber reaction, intraocular pressure (IOP) and CsA concentration were monitored and twelve weeks after the operation, the eyes were extracted for histopathological and morphological examinations. Results There were no differences between the two groups in conjunctival congestion,IOP change and anterior chamber reaction. PCO was less severe in the experimental eyes than in the controls. Light microscopy revealed that posterior capsular membrane in the experimental eyes was slick, with no obvious proliferation,whereas in the controls, there were lens epithelial cell proliferation and cortex regeneration of different degrees.Morphological examination with electron microscope showed that in the experimental eyes, lens epithelial cells did not function actively and apoptosis occurred, whereas in the controls, epithelial cells presented active function. No marked ultrastructural changes were found in either group. Conclusion Cs-DDS can inhibit PCO after intraocular lens implantation in rabbit eyes and does not have toxic effects on the surrounding ocular tissues. Therefore, it has a good potential for clinical use in prevention of PCO.

  3. Hyperbolic metamaterial lens with hydrodynamic nonlocal response.

    Science.gov (United States)

    Yan, Wei; Mortensen, N Asger; Wubs, Martijn

    2013-06-17

    We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion curves numerically. As an application, we find that the focusing characteristics of a HMM lens in the local-response approximation and in the hydrodynamic Drude model can differ considerably. In particular, the optimal frequency for imaging in the nonlocal theory is blueshifted with respect to that in the local theory. Thus, to detect whether nonlocal response is at work in a hyperbolic metamaterial, we propose to measure the near-field distribution of a hyperbolic metamaterial lens.

  4. A polycarbonate ophthalmic-prescription lens series.

    Science.gov (United States)

    Davis, J K

    1978-08-01

    Improvements in polycarbonate material, production techniques, and scratch-resistant coatings, combined with a process-oriented design, have resulted in a precision lens series. Surface quality is comparable to that of untreated glass ophthalmic lenses. The repeatability of the process results in closely controlled axial power and off-axis performance. For most lens prescriptions, the ANSI Z80.1 optical-center specifications for prescription accuracy are maintained through a total field of view of 40 deg for an 8-mm range of center-of-rotation distances. Off-axis astigmatism is controlled for near-point seeing. The lenses are both lighter and thinner than those of crown glass. A scratch-resistant coating reduces the reflections normally associated with high-index (1.586) materials. Impact resistance exceeds that required by ANSI Z80.7 and is many times that required by ANSI Z80.1.

  5. Understanding Science Through the Computational Lens

    Institute of Scientific and Technical Information of China (English)

    Richard M. Karp

    2011-01-01

    This article explores the changing nature of the interaction between computer science and the natural and social sciences.After briefly tracing the history of scientific computation,the article presents the concept of computational lens,a metaphor for a new relationship that is emerging between the world of computation and the world of the sciences.Our main thesis is that,in many scientific fields,the processes being studied can be viewed as computational in nature,in the sense that the processes perform dynamic transformations on information represented as digital data.Viewing natural or engineered systems through the lens of their computational requirements or capabilities provides new insights and ways of thinking.A number of examples are discussed in support of this thesis.The examples are from various fields,including quantum computing,statistical physics,the World Wide Web and the Internet,mathematics,and computational molecular biology.

  6. A Lens Mapping Algorithm for Weak Lensing

    CERN Document Server

    Saini, T D; Saini, Tarun Deep; Raychaudhury, Somak

    2001-01-01

    We develop an algorithm for the reconstruction of the two-dimensional massdistribution of a cluster of galaxies from the observable distortion ofbackground galaxies. From the measured reduced shear gamma_i/(1-kappa) the lensmapping is directly obtained, from which a mass distribution is derived. Thisis unlike other methods where the convergence (kappa) is first obtained. Weshow that this method works best for sub-critical lenses but can be applied toa critical lens away from the critical lines. For finite fields the usualmass-sheet degeneracy is shown to exist in this method as well. We suggest aniterative scheme to remove the mass-sheet degeneracy for the case of asub-critical lens, in the absence of a substantial external shear. The sametechnique can be used with additional information for the case of a criticallens as well. A scheme to reduce the effects of noise is also suggested.

  7. Lens Epithelial Cell Death Secondary to Acanthamoeba Keratitis: Absence of Capsular Bag Opacification Six Years after Cataract Surgery

    Directory of Open Access Journals (Sweden)

    Javier Moreno-Montañés

    2011-12-01

    Full Text Available Purpose: To show the evolution of anterior chamber structures 6 years after cataract surgery in a case with Acanthamoeba keratitis (AK. Methods: A 37-year-old woman with AK receiving long-term treatment with chlorhexidine, propamidine isethionate and steroids developed a white cataract and iris atrophy. Penetrating keratoplasty and cataract surgery were performed with subsequent intraocular pressure elevation requiring Molteno shunt implantation. Two years after the last surgery, endothelial decompensation developed and another penetrating keratoplasty was performed. Intraoperatively, the anterior and posterior capsules were completely transparent. Results: Six years after cataract surgery, the intraocular lens was centered with clear anterior and posterior capsules without lens epithelial cells proliferation. No Soemmering’s ring formation or posterior capsule opacification was found. Also, no zonular damage or pseudophacodonesis was observed. Conclusions: This case suggests that AK infection and AK treatment not only cause white progressive cataract but also lens epithelial cell death. The capsules may be completely clear 6 years after cataract surgery, with a good quality of vision regardless of intraocular lens material or design.

  8. Results of phacoemulsification of cataract complicated by lens subluxation depending on the ring setting method

    Directory of Open Access Journals (Sweden)

    N. G. Zavgorodnjaja

    2015-02-01

    Full Text Available Actuality. Cataract extraction complicated by zonular weakness remains one of the urgent problems of eye microsurgery. Aim. To increase the efficiency of cataract surgery complicated by lens subluxation through comparative analysis of frequency and structure of intra- and postoperative complications, as well as the functional results of surgical treatment of patients depending on the ring setting method. Methods and results. 91 patients (93 eyes were examined, who were operated on complicated cataract, and were divided into 2 groups depending on the method of ring setting. Conclusion. It was established that the offered method of implant capsular ring gives the opportunity to reduce the length of patients’ treatment by 2,6 day, to decrease of 28,43% for complications, and also to avoid such heavy operating complications, as a vitreous prolapse, displacement of the eye lens fragments in a vitreous body, dug up capsule bag.

  9. Design of object surveillance system based on enhanced fish-eye lens

    Institute of Scientific and Technical Information of China (English)

    Jianhui Wu; Kuntao Yang; Qiaolian Xiang; Nanyang Zhang

    2009-01-01

    A new method is proposed for the object surveillance system based on the enhanced fish-eye lens and the high speed digital signal processor (DSP). The improved fish-eye lens images an ellipse picture on the charge-coupled device (CCD) surface, which increases both the utilization rate of the 4:3 rectangular CCD and the imaging resolution, and remains the view angle of 183°. The algorithm of auto-adapted renewal background subtraction (ARBS) is also explored to extract the object from the monitoring image. The experimental result shows that the ARBS algorithm has high anti-jamming ability and high resolution, leading to excellent object detecting ability from the enhanced elliptical fish-eye image under varies en-vironments. This system has potential applications in different security monitoring fields due to its wide monitoring space, simple structure, working stability, and reliability.

  10. A stereoscopic lens for digital cinema cameras

    Science.gov (United States)

    Lipton, Lenny; Rupkalvis, John

    2015-03-01

    Live-action stereoscopic feature films are, for the most part, produced using a costly post-production process to convert planar cinematography into stereo-pair images and are only occasionally shot stereoscopically using bulky dual-cameras that are adaptations of the Ramsdell rig. The stereoscopic lens design described here might very well encourage more live-action image capture because it uses standard digital cinema cameras and workflow to save time and money.

  11. Rose-K contact lens for keratoconus

    Directory of Open Access Journals (Sweden)

    Jain Arun

    2007-01-01

    Full Text Available Aim: To report clinical experience and the comparative value of axial and instantaneous topography data in fitting Rose-K design contact lenses in moderate and severe keratoconus. Materials and Methods: Thirty-eight eyes (of 23 patients with keratoconus were fitted with Rose-K design contact lenses and followed up for at least six months or more. Visual acuity with habitual vision correction available was measured. Axial and instantaneous topography maps for each eye were recorded. Contact lens wear comfort was graded on a ten point rating scale every three months. Results: Fourteen (100% moderate keratoconus eyes (average Sim K 48.61 ± 1.24D and 23 of 24 (96% of severe keratoconus eyes (average Sim K 60.88 ± 5.31D were successfully fitted with the Rose-K lenses. Final fit contact lenses in severe keratoconus had statistically significant steeper base curves compared to average axial corneal curvature than in moderate keratoconus eyes. Average simulated corneal curvature on axial maps predicted final fit contact lens base curves significantly better than on instantaneous maps. Thirty-three of the 37 eyes fitted with contact lenses maintained wear comfort over average follow up period of 13 ± 3.5 months. Conclusions: Rose-K design rigid contact lenses are successful in visually rehabilitating 100% of moderate and 96% of severe keratoconus eyes. Most patients (90% maintained contact lens wear comfort. Corneal curvature on axial maps is a better predictive of base curve of final fit contact lens.

  12. Comparison and Calibration of Mobile Phone Fisheye Lens and Regular Fisheye Lens via Equidistant Model

    Directory of Open Access Journals (Sweden)

    Cumhur Sahin

    2016-01-01

    Full Text Available Nowadays, mobile phones are more than a device that can only satisfy the communication need between people. In addition to providing ease to human lives with various applications, lens kits that can be integrated to mobile phones have recently been introduced. Fisheye lenses that are compliant with mobile phones are one of these new types of equipment. Since fisheye lenses integrated with mobile phones are lightweight and easy to use, they are advantageous. In addition to this advantage, whether fisheye lens and mobile phone combination can be used in a photogrammetric way is experimented, and if so, what will be the result. The main purpose of this study is to test fisheye lens equipment used with mobile phones. In this study, standard calibration of “Olloclip 3 in one” fisheye lens used with iPhone 4S mobile phone and “Nikon FC-E9” fisheye lens used with Nikon Coolpix8700 are compared based on equidistant model. The results of these calibrations are analyzed, using photogrammetric bundle block adjustment. This study suggests a precalibration process of these kinds of hardware for the photogrammetric process in the test field.

  13. Effects of Different Contact Lens Designs on Visual Quality Among the Soft Spherical Contact Lens Users

    Directory of Open Access Journals (Sweden)

    Mustafa Demir

    2013-10-01

    Full Text Available Purpose: To evaluate the effects of different lens designs on visual quality among soft spherical contact lens users. Material and Method: Forty eyes of twenty patients from our contact lens unit were included in this study. Refractive errors of the patients were between -0.50 and -6.0 diopters with 0.05. Total higher order aberration mean rms value was 0.29±0.10 µm without glasses, while it was 0.33±0.10 µm with Balafilcon A lenses and 0.31±0.10 µm with Senofilcon A lenses. Higher order aberration values measured after contact lens application did not show a significant difference for two contact lens designs (p>0.05. Discussion: High and low contrast sensitivity values were better with spectacles compared to contact lenses. We did not observe significant difference in higher order aberration values and visual quality between aspheric and spheric designed lenses. (Turk J Ophthalmol 2013; 43: 321-5

  14. CMB lens sample covariance and consistency relations

    Science.gov (United States)

    Motloch, Pavel; Hu, Wayne; Benoit-Lévy, Aurélien

    2017-02-01

    Gravitational lensing information from the two and higher point statistics of the cosmic microwave background (CMB) temperature and polarization fields are intrinsically correlated because they are lensed by the same realization of structure between last scattering and observation. Using an analytic model for lens sample covariance, we show that there is one mode, separately measurable in the lensed CMB power spectra and lensing reconstruction, that carries most of this correlation. Once these measurements become lens sample variance dominated, this mode should provide a useful consistency check between the observables that is largely free of sampling and cosmological parameter errors. Violations of consistency could indicate systematic errors in the data and lens reconstruction or new physics at last scattering, any of which could bias cosmological inferences and delensing for gravitational waves. A second mode provides a weaker consistency check for a spatially flat universe. Our analysis isolates the additional information supplied by lensing in a model-independent manner but is also useful for understanding and forecasting CMB cosmological parameter errors in the extended Λ cold dark matter parameter space of dark energy, curvature, and massive neutrinos. We introduce and test a simple but accurate forecasting technique for this purpose that neither double counts lensing information nor neglects lensing in the observables.

  15. Pitfalls in aphakic contact lens fitting

    Directory of Open Access Journals (Sweden)

    Dada Vijay

    1990-01-01

    Full Text Available We examined 23 consecutive cases of unilateral aphakia reporting to the contact lens office for endothelial count and morphology, corneal thickness and toricity. The fellow eye served as a control in all the cases. It was found that there is a significant drop in the central endothelial cell density, and change in the size and shape of the cells. These observations indicate a thermodynamically unstable state. The aphakic corneas were thicker than the controls but not to a significant extent. The cell count and pachymetry had no statistical correlation. Toricity of the aphakic corneas make successful fitting of a lens difficult. Since prolonged use of extended wear gas permeable as well as hydrogel lenses have a deleterious effect on the endothelium it is suggested that a careful case selection be made and strict monitoting carried out at follow up. These corneas are liable for decompensation with only mild noxious stimuli. This article is intended to acquaint the ophthalmologist with the pitfalls in aphakic contact lens fitting so that a cautious follow up may be planned.

  16. Retina projection using curved lens arrays

    Science.gov (United States)

    Yen, Hao-Ren; Su, Guo-Dung J.

    2016-09-01

    In this paper, we propose a multi-channel imaging system which combines the principles of an insect's compound eye and optical cluster eye. The system consists of two curved structure lens arrays with different pitches. Both of them have the same curvature and the radiuses of the lenses in the arrays are optimized to focus rays on the retina. The optical axes of different channels are tilted to each other in order to reduce the optical system volume and transmit a wide field of view. Each channel of an array of multiple optical system transfers only a part of the field of view. Each partial image passes through each channel and stitches together on the retina to reconstruct a complete image. In order to simulate the image stitching, we also build an eye model. The thickness from the panel to the last surface of lens group is less than 25mm. The panel size is designed to be 4 inch which is the scale of eyeglass. The system can provide a large field of view about 150 degrees which is much wider than the commercial products. By using the 3D printer, we can make a model of lens array to achieve our design.

  17. Adaptive Liquid Lens Actuated by Droplet Movement

    Directory of Open Access Journals (Sweden)

    Chao Liu

    2014-08-01

    Full Text Available In this paper we report an adaptive liquid lens actuated by droplet movement. Four rectangular PMMA (Polymethyl Methacrylate substrates are stacked to form the device structure. Two ITO (Indium Tin Oxide sheets stick on the bottom substrate. One PMMA sheet with a light hole is inserted in the middle of the device. A conductive droplet is placed on the substrate and touches the PMMA sheet to form a small closed reservoir. The reservoir is filled with another immiscible non-conductive liquid. The non-conductive liquid can form a smooth concave interface with the light hole. When the device is applied with voltage, the droplet stretches towards the reservoir. The volume of the reservoir reduces, changing the curvature of the interface. The device can thus achieve the function of an adaptive lens. Our experiments show that the focal length can be varied from −10 to −159 mm as the applied voltage changes from 0 to 65 V. The response time of the liquid lens is ~75 ms. The proposed device has potential applications in many fields such as information displays, imaging systems, and laser scanning systems.

  18. CYLINDER LENS ALIGNMENT IN THE LTP

    Energy Technology Data Exchange (ETDEWEB)

    TAKACS, P.Z.

    2005-07-26

    The Long Trace Profiler (LTP), is well-suited for the measurement of the axial figure of cylindrical mirrors that usually have a long radius of curvature in the axial direction but have a short radius of curvature in the sagittal direction. The sagittal curvature causes the probe beam to diverge in the transverse direction without coming to a focus on the detector, resulting in a very weak signal. It is useful to place a cylinder lens into the optical system above the mirror under test to refocus the sagittal divergence and increase the signal level. A positive cylinder lens can be placed at two positions above the surface: the Cat's Eye reflection position and the Wavefront-Matching position. The Cat's Eye position, is very tolerant to mirror misalignment, which is not good if absolute axial radius of curvature is to be measured. Lateral positioning and rotational misalignments of lens and the mirror combine to produce unusual profile results. This paper looks at various alignment issues with measurements and by raytrace simulations to determine the best strategy to minimize radius of curvature errors in the measurement of cylindrical aspheres.

  19. Achromobacter xylosoxidans keratitis after contact lens usage.

    Science.gov (United States)

    Park, Jung Hyun; Song, Nang Hee; Koh, Jae Woong

    2012-02-01

    To report on Achromobacter xylosoxidans keratitis in two healthy patients who had worn contact lenses foran extended period of time. A 36-year-old female and a 21-year-old female visited our hospital with ocular pain and blurred vision. Both patients had a history of wearing soft contact lenses for over fve years with occasional overnight wear. At the initial presentation, a slit lamp examination revealed corneal stromal infiltrations and epithelial defects with peripheral neovascularization in both patients. Microbiological examinations were performed from samples of corneal scrapings, contact lenses, contact lens cases, and solution. The culture resulting from the samples taken from the contact lenses, contact lens cases, and solution were all positive for Achromobacter xylosoxidans. Confrming that the direct cause of the keratitis was the contact lenses, the frst patient was prescribed ceftazidime and amikacin drops sensitive to Achromobacter xylosoxidans. The second patient was treated with 0.3% gatifoxacin and fortifed tobramycin drops. After treatment, the corneal epithelial defects were completely healed, and subepithelial corneal opacity was observed. Two cases of Achromobacter xylosoxidans keratitis were reported in healthy young females who wore soft contact lenses. Achromobacter xylosoxidans should be considered a rare but potentially harmful pathogen for lens-induced keratitis in healthy hosts.

  20. Ultrasound field measurement using a binary lens

    CERN Document Server

    Clement, Gregory T; Kamakura, Tomoo

    2014-01-01

    Field characterization methods using a scattering target in the absence of a point-like receiver have been well described in which scattering is recorded by a relatively large receiver located outside the field of measurement. Unfortunately, such methods are prone to artifacts due to averaging across the receiver surface. To avoid this problem while simultaneously increasing the gain of a received signal, the present study introduces a binary plate lens designed to focus spherically-spreading waves onto a planar region having a nearly-uniform phase proportional to that of the target location. The lens is similar to a zone plate, but modified to produce a bi-convex-like behavior, such that it focuses both planar and spherically spreading waves. A measurement device suitable for characterizing narrowband ultrasound signals in air is designed around this lens by coupling it to a target and planar receiver. A prototype device is constructed and used to characterize the field of a highly-focused 400 kHz air transd...

  1. Rho GTPase inactivation impairs lens growth and integrity.

    Science.gov (United States)

    Rao, Vasantha; Wawrousek, Eric; Tamm, Ernst R; Zigler, Samuel

    2002-02-01

    To elucidate the significance of Rho GTPase signaling on lens growth and structural integrity, we have selectively inactivated Rho GTPase in the ocular lens. To achieve this tissue-specific inactivation, a transgene encoding the C3-exoenzyme from Clostridium botulinum has been expressed in mice under transcriptional control of the lens-specific alphaA-crystallin promoter. C3-exoenzyme is known to selectively inactivate all Rho GTPase isoforms by ADP-ribosylating an asparagine residue at position 41. Mice expressing the C3-exoenzyme transgene exhibited selective ocular defects, including cataract and microphthalmia. Extralenticular effects included ocular hemorrhage (blood accumulation in the anterior and posterior chambers of the eye) and abnormalities of the iris including focal attachments to lens and cornea (synechiae). C3-transgene expression was found only in the lens and not in the other ocular tissues as determined by RT-PCR analysis. Histologic examination of the eyes of C3 transgenic mice from two independent lines revealed extensive abnormalities of the lens, including defective fiber cell differentiation and elongation, ruptured posterior lens capsule, and thickened anterior lens capsule. Electron microscopic analysis of hemorrhaged C3 eyes showed abnormalities in the posterior hyaloid vessels. Collectively these data reveal the importance of Rho GTPase signaling in regulating lens growth and maintenance of lens transparency.

  2. Review of small aspheric glass lens molding technologies

    Science.gov (United States)

    Yin, Shaohui; Jia, Hongpeng; Zhang, Guanhua; Chen, Fengjun; Zhu, Kejun

    2017-01-01

    Aspheric lens can eliminate spherical aberrations, coma, astigmatism, field distortions, and other adverse factors. This type of lens can also reduce the loss of light energy and obtain high-quality images and optical characteristics. The demand for aspheric lens has increased in recent years because of its advantageous use in the electronics industry, particularly for compact, portable devices and high-performance products. As an advanced manufacturing technology, the glass lens molding process has been recognized as a low-cost and high-efficiency manufacturing technology for machining small-diameter aspheric lens for industrial production. However, the residual stress and profile deviation of the glass lens are greatly affected by various key technologies for glass lens molding, including glass and mold-die material forming, mold-die machining, and lens molding. These key technical factors, which affect the quality of the glass lens molding process, are systematically discussed and reviewed to solve the existing technical bottlenecks and problems, as well as to predict the potential applicability of glass lens molding in the future.

  3. Hybridizing Conversational and Clear Speech to Investigate the Source of Increased Intelligibility in Speakers with Parkinson's Disease

    Science.gov (United States)

    Tjaden, Kris; Kain, Alexander; Lam, Jennifer

    2014-01-01

    Purpose: A speech analysis-resynthesis paradigm was used to investigate segmental and suprasegmental acoustic variables explaining intelligibility variation for 2 speakers with Parkinson's disease (PD). Method: Sentences were read in conversational and clear styles. Acoustic characteristics from clear sentences were extracted and applied to…

  4. Novel Scanning Lens Instrument for Evaluating Fresnel Lens Performance: Equipment Development and Initial Results (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, R.; Miller, D. C.; Kurtz, S. R.; Anton, I.; Sala, G.

    2013-07-01

    A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.

  5. Differences in regeneration between hurricane damaged and clear-cut mangrove stands 25 years after clearing

    OpenAIRE

    Ferwerda, J.G.; Ketner, P.; McGuiness, K.A.

    2007-01-01

    The effect of human disturbance on mangrove forest may be substantially different from the effects of natural disturbances. This paper describes differences in vegetation composition and structure of five vegetation types in two mangrove areas near Darwin, Australia, 25 years after disturbance. The vegetation in clear-felled forest showed more adult Avicennia marina than in the hurricane-affected forest, and a virtual absence of A. marina juveniles and saplings. This indicates that A. marina ...

  6. Forensic Analysis of a Contact Lens in a Murder Case.

    Science.gov (United States)

    Zwerling, Charles S

    2016-03-01

    Contact lenses have had rare relevance in trials and/or investigations. After 5 years of burial, orbital remnants were retrieved from an exhumed body and subsequently identified as a key piece of material evidence in a murder trial. The exhumed case materials were evaluated under laboratory conditions and were determined to be contact lens remnants. Contact lens fracture and burial simulation studies were performed to provide additional corroboration of the physical findings of the exhumed contact lens remnants. This material evidence was instrumental in providing factual proof refuting the defendant's testimony in the murder trial. A brief history of contact lens composition and use is provided for understanding the methods and observational results. This forensic case study represents the first published documentation of a contact lens from an exhumed body being used in a murder investigation and establishes an operational procedure for future forensic contact lens examinations.

  7. Spatial distribution of metabolites in the human lens.

    Science.gov (United States)

    Tamara, Semen O; Yanshole, Lyudmila V; Yanshole, Vadim V; Fursova, Anjella Zh; Stepakov, Denis A; Novoselov, Vladimir P; Tsentalovich, Yuri P

    2016-02-01

    Spatial distribution of 34 metabolites along the optical and equatorial axes of the human lens has been determined. For the majority of metabolites, the homogeneous distribution has been observed. That suggests that the rate of the metabolite transformation in the lens is low due to the general metabolic passivity of the lens fiber cells. However, the redox processes are active in the lens; as a result, some metabolites, including antioxidants, demonstrate the "nucleus-depleted" type of distribution, whereas secondary UV filters show the "nucleus-enriched" type. The metabolite concentrations at the lens poles and equator are similar for all metabolites under study. The concentric pattern of the "nucleus-depleted" and "nucleus-enriched" distributions testifies that the metabolite distribution inside the lens is mostly governed by a passive diffusion, relatively free along the fiber cells and retarded in the radial direction across the cells. No significant difference in the metabolite distribution between the normal and cataractous human lenses was found.

  8. CLEARS An Education and Research Tool for Computational Semantics

    CERN Document Server

    Milward, D; Maier, Hans J; Pinkal, M; Milward, David; Konrad, Karsten; Maier, Holger; Pinkal, Manfred

    1996-01-01

    The CLEARS (Computational Linguistics Education and Research for Semantics) tool provides a graphical interface allowing interactive construction of semantic representations in a variety of different formalisms, and using several construction methods. CLEARS was developed as part of the FraCaS project which was designed to encourage convergence between different semantic formalisms, such as Montague-Grammar, DRT, and Situation Semantics. The CLEARS system is freely available on the WWW from http://coli.uni-sb.de/~clears/clears.html

  9. Lens rigidity with trapped geodesics in two dimensions

    CERN Document Server

    Croke, Christopher B

    2011-01-01

    We consider the scattering and lens rigidity of compact surfaces with boundary that have a trapped geodesic. In particular we show that the flat cylinder and the flat M\\"obius strip are determined by their lens data. We also see by example that the flat M\\"obius strip is not determined by it's scattering data. We then consider the case of negatively curved cylinders with convex boundary and show that they are lens rigid.

  10. The action of selenite on ATP synthesis in rat lens

    OpenAIRE

    Adamchak, Marsha Ann

    1986-01-01

    A subcutaneous injection of sodium selenite (30 umol/kg body weight) in 10â day old rats produced a cataract within 72 hours. Lens opacification was preceded by a 15% decrease in ATP content. Lens ATP did not fully recover to control concentrations by 11 days postâ injection. A moderate correlation existed between lens weight and total ATP content in control lenses

  11. Effects of Coupling Lens on Optical Refrigeration of Semiconductors

    Institute of Scientific and Technical Information of China (English)

    DING Kai; ZENG Yi-Ping

    2008-01-01

    Optical refrigeration of semiconductors is encountering efficiency difficulties caused by nonradiative recombination and luminescence trapping.A commonly used approach for enhancing luminescence efficiency of a semiconductor device is coupling a lens with the device. We quantitatively study the effects of a coupling lens on optical refrigeration based on rate equations and photon recycling,and calculated cooling efficiencies of different coupling mechanisms and of different lens materials.A GaAs/GaInP heterostructure coupled with a homo-epitaxial GaInP hemispherical lens is recommended.

  12. 600 Volt Stretched Lens Array for Solar Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ENTECH, Auburn, NASA, and others have recently developed a new space photovoltaic array called the Stretched Lens Array (SLA), offering unprecedented performance...

  13. Electromagnetic Mathematical Modeling of 3D Supershaped Dielectric Lens Antennas

    Directory of Open Access Journals (Sweden)

    L. Mescia

    2016-01-01

    Full Text Available The electromagnetic analysis of a special class of 3D dielectric lens antennas is described in detail. This new class of lens antennas has a geometrical shape defined by the three-dimensional extension of Gielis’ formula. The analytical description of the lens shape allows the development of a dedicated semianalytical hybrid modeling approach based on geometrical tube tracing and physical optic. In order to increase the accuracy of the model, the multiple reflections occurring within the lens are also taken into account.

  14. Lens regeneration in axolotl: new evidence of developmental plasticity

    Directory of Open Access Journals (Sweden)

    Suetsugu-Maki Rinako

    2012-12-01

    Full Text Available Abstract Background Among vertebrates lens regeneration is most pronounced in newts, which have the ability to regenerate the entire lens throughout their lives. Regeneration occurs from the dorsal iris by transdifferentiation of the pigment epithelial cells. Interestingly, the ventral iris never contributes to regeneration. Frogs have limited lens regeneration capacity elicited from the cornea during pre-metamorphic stages. The axolotl is another salamander which, like the newt, regenerates its limbs or its tail with the spinal cord, but up until now all reports have shown that it does not regenerate the lens. Results Here we present a detailed analysis during different stages of axolotl development, and we show that despite previous beliefs the axolotl does regenerate the lens, however, only during a limited time after hatching. We have found that starting at stage 44 (forelimb bud stage lens regeneration is possible for nearly two weeks. Regeneration occurs from the iris but, in contrast to the newt, regeneration can be elicited from either the dorsal or the ventral iris and, occasionally, even from both in the same eye. Similar studies in the zebra fish concluded that lens regeneration is not possible. Conclusions Regeneration of the lens is possible in the axolotl, but differs from both frogs and newts. Thus the axolotl iris provides a novel and more plastic strategy for lens regeneration.

  15. An Ultrasonic Lens Design Based on Prefractal Structures

    Directory of Open Access Journals (Sweden)

    Sergio Castiñeira-Ibáñez

    2016-04-01

    Full Text Available The improvement in focusing capabilities of a set of annular scatterers arranged in a fractal geometry is theoretically quantified in this work by means of the finite element method (FEM. Two different arrangements of rigid rings in water are used in the analysis. Thus, both a Fresnel ultrasonic lens and an arrangement of rigid rings based on Cantor prefractals are analyzed. Results show that the focusing capacity of the modified fractal lens is better than the Fresnel lens. This new lens is believed to have potential applications for ultrasonic imaging and medical ultrasound fields.

  16. A Novel Fisheye-Lens-Based Photoacoustic System

    Science.gov (United States)

    Choi, Hojong; Ryu, Jaemyung; Kim, Jungsuk

    2016-01-01

    This paper presents a novel fisheye-lens-based photoacoustic (PA) system. In conventional PA systems, mechanical motors are utilized to obtain the target information due to the small fields of view of such systems. The use of such motors introduces mechanical noise, which is difficult to remove when processing the echo signals. A fisheye lens system offering a wide field of view would effectively reduce the motor effects (i.e., the noise) and enable the system to have a wide field of view. Therefore, in this work, we propose a novel fisheye lens scheme and describe a PA system based on the developed lens scheme. In addition, to confirm the feasibility of the fisheye-lens-based PA system, we present the typical pulse-echo responses obtained using a 20 MHz single element immersion transducer and the echo signals measured from bull’s eye tissue samples separated by approximately 4, 6, 8, and 10 cm diagonally and 2 cm vertically from the fisheye lens. The experimental results demonstrate that the echo signal amplitudes, their center frequencies, and the −6 dB bandwidths obtained using red, green, and blue lights and a fisheye lens are acceptable when the fisheye lens is separated from a sample both diagonally and vertically. Therefore, fisheye-lens-based PA systems could be a potential method of achieving wide fields of view while reducing the mechanical motor effects. PMID:27999376

  17. Patient comfort following thirty minutes of lens wear: piggy-back versus conventional rigid-lens wear

    Directory of Open Access Journals (Sweden)

    W. D.H. Gillan

    2014-08-01

    Full Text Available Discomfort when wearing contact lenses, especially rigid contact lenses, is a common complaint amongst neophyte as well as experienced contact lens wearers. Wearing a piggy-back system of contact lenses has been shown to improve comfort and wearing time, especially in keratoconic subjects. Twenty two normal subjects wore a rigid lens or a piggy-back system of lenses for thirty minutes and after a thirty minute break swopped the mode of lens wear and wore the second modality for a thirty minute period. This study suggests that a piggy-back lens system provides improved comfort compared to wearing a rigid lens on its own. The order of lens wear might, however, influence the perceived comfort.

  18. In vitro effects of selected contact lens care solutions on Acanthamoeba castellanii strains in Poland.

    Science.gov (United States)

    Padzik, Marcin; Chomicz, Lidia; Szaflik, Jacek P; Chruścikowska, Agnieszka; Perkowski, Konrad; Szaflik, Jerzy

    2014-11-01

    Free-living, cosmopolitan amoebae of the Acanthamoeba genus may be the causative agents of Acanthamoeba keratitis (AK) - a progressive, vision-threatening infection of the human cornea described particularly among contact lens wearers. Use of contact lens care solutions, effective against these organisms, is important in preventing AK infections. 3 different strains of Acanthamoeba castellanii of the T4 genotype (Neff strain and two others, isolated from patients with AK) were exposed to 4 selected multipurpose contact lens care solutions available in Poland: Ciba Vision AoSept Plus, Bausch & Lomb ReNu MultiPlus, Alcon Opti-Free, Ciba Vision Solo Care Aqua. No amoebicidal effect was observed. The strongest amoebostatic effect was visible after 24h of exposition to Opti-Free and ReNu solution and associated with percentage increase of rounded, motionless forms. This is significantly longer than minimum disinfection time recommended by manufacturers of all tested multipurpose solutions. Surprisingly, no clear induction of the encystation process was observed.

  19. A safe method of ciliary sulcus fixation of foldable intraocular lens using a ciliary sulcus guide.

    Science.gov (United States)

    Can, Ertuğrul; Gül, Adem; Birinci, Hakkı

    2016-08-01

    To describe a novel technique for implantation of intraocular lens in the absence of capsular support using a ciliary sulcus guide. Based on the anatomic knowledge of the ciliary sulcus and the sclera, a new instrument was developed to pierce the needle safely through the ciliary sulcus and sclera. While the foldable lens is stored inside the cartridge, the leading haptic is sutured with a cow-hitch knot. The needle is then inserted into the ciliary sulcus guide. The tip of the guide is inserted from the corneal incision and proceeded under the iris to touch and fit the ciliary sulcus. The needle is pushed from back side. The needle comes out at precise point at the sclera. Implantation of the lens was performed through a 2.8 mm clear cornea incision using the injector. The trailing haptic is tied after implantation, and then the same procedure is performed at the opposite side. We performed this technique to 15 aphakic eyes without sufficient capsular support. There was no bleeding or other intraoperative complication. All the points coming out the sclera were between 2 and 2.5 mm from the limbus. The ab interno technique for scleral fixation of IOL is quicker, easier and less traumatic then ab externo techniques. A new ciliary sulcus guide which is usable with both straight and curved needles eliminates the blind maneuvers of ab interno technique and makes this technique more safe and precise.

  20. Remote nano-optical beam focusing lens by illusion optics

    Science.gov (United States)

    Margousi, David; Shoorian, Hamed Reza

    2014-08-01

    In this paper, as a new application of illusion optics, a nano-optical plasmonic focusing lens structure is proposed to manipulate the light remotely by employing illusion optics theory. Plasmonic nano-optic lenses that enable super-focusing beyond the diffraction limit have been proposed as an alternative to the conventional dielectric-based refractive lenses. In the presence of an illusion device, the electromagnetic plane-waves can penetrate into a metal layer and a clear focus appears. When the illusion device is removed, waves are blocked to transmit through the metal wall. In comparison with conventional methods, our proposed method avoids any physical changes or damages in the original structure. The proposed structure can be realized by isotropic layered materials, using effective medium theory. The special feature of the proposed structure and the device concepts introduced in this work gives it an opportunity to be used as a flexible element in ultrahigh nano-scale integrated circuits for miniaturization and tuning purposes.

  1. FOCUSING BY A HIGH-POWER, LOW-FRESNEL-NUMBER LENS - THE FLY FACET LENS

    NARCIS (Netherlands)

    STAVENGA, DG; VANHATEREN, JH

    1991-01-01

    Diffraction by fly facet lenses has been investigated by photographing the diffraction patterns at various distances from a facet lens whose power was estimated to be 2.03 x 10(4) D. We studied three different aperture diameters with Fresnel numbers of the order of unity. A large focal shift was pro

  2. Focusing by a high-power, low-Fresnel-number lens : the fly facet lens

    NARCIS (Netherlands)

    Stavenga, D.G.; Hateren, J.H. van

    1991-01-01

    Diffraction by fly facet lenses has been investigated by photographing the diffraction patterns at various distances from a facet lens whose power was estimated to be 2.03 x 10(4) D. We studied three different aperture diameters with Fresnel numbers of the order of unity. A large focal shift was pro

  3. The BOSS Emission-Line Lens Survey. IV. : Smooth Lens Models for the BELLS GALLERY Sample

    CERN Document Server

    Shu, Yiping; Mao, Shude; Kochanek, Christopher S; Pérez-Fournon, Ismael; Oguri, Masamune; Montero-Dorta, Antonio D; Cornachione, Matthew A; Marques-Chaves, Rui; Zheng, Zheng; Brownstein, Joel R; Ménard, Brice

    2016-01-01

    We present \\textsl{Hubble Space Telescope} (\\textsl{HST}) F606W-band imaging observations of 21 galaxy-Ly$\\alpha$ emitter lens candidates in the Baryon Oscillation Spectroscopic Survey (BOSS) Emission-Line Lens Survey (BELLS) for GALaxy-Ly$\\alpha$ EmitteR sYstems (BELLS GALLERY) survey. 17 systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately $0.55$, while the lensed sources are Ly$\\alpha$ emitters (LAEs) at redshifts from 2 to 3. Although the \\textsl{HST} imaging data are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thorough exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are on average $60\\%$ larger than those of the BELLS lenses because of the much higher source redshifts which will allow a detailed investigation of the radius evolution of the mass profile...

  4. An "ESA-affordable" Laue-lens

    DEFF Research Database (Denmark)

    Lund, Niels

    2005-01-01

    With ESA's INTEGRAL mission gamma-ray astronomy has advanced to the point where major scientific advances must be expected from detailed studies of the many new point sources. The interest in developing focusing telescopes operating in the soft gamma-ray regime up to 1 MeV is therefore mounting...... constraints of a specific medium size launch vehicle. The introduction of the lens mass as a primary design driver has some surprising effects for the choice of material for the crystals and new tradeoff considerations are introduced....

  5. LensTools: Weak Lensing computing tools

    Science.gov (United States)

    Petri, A.

    2016-02-01

    LensTools implements a wide range of routines frequently used in Weak Gravitational Lensing, including tools for image analysis, statistical processing and numerical theory predictions. The package offers many useful features, including complete flexibility and easy customization of input/output formats; efficient measurements of power spectrum, PDF, Minkowski functionals and peak counts of convergence maps; survey masks; artificial noise generation engines; easy to compute parameter statistical inferences; ray tracing simulations; and many others. It requires standard numpy and scipy, and depending on tools used, may require Astropy (ascl:1304.002), emcee (ascl:1303.002), matplotlib, and mpi4py.

  6. CATARACT SURGERY AND INTRAOCULAR LENS POWER CALCULATION IN A PATIENT WITH ANTERIOR MEGALOPHTHALMOS WITH NORMAL SIZED CRYSTALLINE LENS; CASE REPORT

    Directory of Open Access Journals (Sweden)

    Glišić Selimir

    2015-12-01

    Full Text Available Cataract surgery and intraocular lens power calculation is challenging in patients with anterior megalophthalmos and cataract, with postoperative refractive surprise frequently reported. Deep anterior chamber in these patients substantially influence effective lens position. To minimize possibility of refractive surprise, we used Haigis formula that takes into account anterior chamber depth in the lens power calculation for our patient. Cataract was managed by phakoemulsification with standard intraocular lens implanted in the capsular bag. Postoperatively, satisfying refractive result was achieved and refractive surprise was avoided.

  7. Comparison of Strong Gravitational Lens Model Software II. HydraLens: Computer-Assisted Strong Gravitational Lens Model Generation and Translation

    CERN Document Server

    Lefor, Alsn T

    2015-01-01

    The behavior of strong gravitational lens model software in the analysis of lens models is not necessarily consistent among the various software available, suggesting that the use of several models may enhance the understanding of the system being studied. Among the publicly available codes, the model input files are heterogeneous, making the creation of multiple models tedious. An enhanced method of creating model files and a method to easily create multiple models, may increase the number of comparison studies. HydraLens simplifies the creation of model files for four strong gravitational lens model software packages, including Lenstool, Gravlens/Lensmodel, glafic and PixeLens, using a custom designed GUI for each of the four codes that simplifies the entry of the model for each of these codes, obviating the need for user manuals to set the values of the many flags and in each data field. HydraLens is designed in a modular fashion, which simplifies the addition of other strong gravitational lens codes in th...

  8. Fusarium and Candida albicans biofilms on soft contact lenses: model development, influence of lens type and susceptibility to lens care solutions

    Science.gov (United States)

    Fungal keratitis is commonly caused by Fusarium species, while cases of Candida-associated keratitis are less frequent. Recent outbreaks of Fusarium keratitis were associated with contact lens wear and with MoistureLoc contact lens care solution, and biofilm formation on contact lens/lens cases was...

  9. Transcriptome analysis of Nautilus and pygmy squid developing eye provides insights in lens and eye evolution.

    Science.gov (United States)

    Sousounis, Konstantinos; Ogura, Atsushi; Tsonis, Panagiotis A

    2013-01-01

    Coleoid cephalopods like squids have a camera-type eye similar to vertebrates. On the other hand, Nautilus (Nautiloids) has a pinhole eye that lacks lens and cornea. Since pygmy squid and Nautilus are closely related species they are excellent model organisms to study eye evolution. Having being able to collect Nautilus embryos, we employed next-generation RNA sequencing using Nautilus and pygmy squid developing eyes. Their transcriptomes were compared and analyzed. Enrichment analysis of Gene Ontology revealed that contigs related to nucleic acid binding were largely up-regulated in squid, while the ones related to metabolic processes and extracellular matrix-related genes were up-regulated in Nautilus. These differences are most likely correlated with the complexity of tissue organization in these species. Moreover, when the analysis focused on the eye-related contigs several interesting patterns emerged. First, contigs from both species related to eye tissue differentiation and morphogenesis as well as to cilia showed best hits with their Human counterparts, while contigs related to rabdomeric photoreceptors showed the best hit with their Drosophila counterparts. This bolsters the idea that eye morphogenesis genes have been generally conserved in evolution, and compliments other studies showing that genes involved in photoreceptor differentiation clearly follow the diversification of invertebrate (rabdomeric) and vertebrate (ciliated) photoreceptors. Interestingly some contigs showed as good a hit with Drosophila and Human homologues in Nautilus and squid samples. One of them, capt/CAP1, is known to be preferentially expressed in Drosophila developing eye and in vertebrate lens. Importantly our analysis also provided evidence of gene duplication and diversification of their function in both species. One of these genes is the Neurofibromatosis 1 (NF1/Nf1), which in mice has been implicated in lens formation, suggesting a hitherto unsuspected role in the evolution

  10. The Effect of Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconus Patients

    Directory of Open Access Journals (Sweden)

    Ali Bülent Çankaya

    2012-05-01

    Full Text Available Pur po se: To determine and compare the corneal biomechanical properties in keratoconus patients using rigid gas permeable contact lenses and keratoconus patients who do not use contact lenses. Ma te ri al and Met hod: The study consisted of 70 healthy controls (Group A, 27 ketatoconus subjects who do not use contact lens (Group B and 36 rigid gas permeable contact lens using keratoconic patients (Group C. Corneal viscoelastic parameters were measured with an Ocular response analyzer (ORA. Central corneal thickness was measured with an ultrasonic pachymeter. The differences in ORA parameters between the groups were compared. Re sults: The mean corneal hysteresis (CH in Groups A, B, and C were 10.3±1.5 mm Hg, 7.8±1.4 mm Hg, and 7.4±1.2 mm Hg, respectively. The differences in mean CH between Group A and the other two groups were statistically significant (p<0.01 for both comparisons, but no statistically significant difference was found between groups B and C in terms of mean CH (p=0.61. The mean corneal resistance factor (CRF was 10.7±1.9 in Group A compared with 6.6±1.6 in Group B and 6.1±1.5 in Group C. The differences in mean CRF between Group A and the other two groups were statistically significant (p<0.01 for both comparisons. There was no significant difference in CRF between the keratoconus eyes with or without rigid gas permeable contact lens usage (p=0.57. Dis cus si on: Our results suggest that ORA-generated parameters may be different in subjects with keratoconus. Corneal biomechanical parameters did not demonstrate a clear trend of change with rigid gas permeable contact lens usage. (Turk J Ophthalmol 2012; 42: 197-201

  11. High Dk piggyback contact lens system for contact lens-intolerant keratoconus patients

    Directory of Open Access Journals (Sweden)

    Tomris Sengor

    2011-03-01

    Full Text Available Tomris Sengor, Sevda Aydin Kurna, Suat Aki, Yelda ÖzkurtFatih Sultan Mehmet Training and Research Hospital, Istanbul, TurkeyBackground: The aim of the study was to examine the clinical success of high Dk (oxygen permeability piggyback contact lens (PBCL systems for the correction of contact lens intolerant keratoconus patients.Methods: Sixteen patients (29 eyes who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen transmissibility or Dk/t = 150 units and fluorosilicone methacrylate copolymer (Dk/t = 100 units lenses were chosen as the PBCL systems. The clinical examinations included visual acuity and corneal observation by biomicroscopy, keratometer reading, and fluorescein staining before and after fitting the PBCL system.Results: Indications for using PBCL system were: lens stabilization and comfort, improving comfort, and adding protection to the cone. Visual acuities increased significantly in all of the patients compared with spectacles (P = 0. Improvement in visual acuity compared with rigid lenses alone was recorded in 89.7% of eyes and no alteration of the visual acuity was observed in 10.3% of the eyes. Wearing time of PBCL systems for most of the patients was limited time (mean 6 months, range 3–12 months; thereafter they tolerated rigid lenses alone except for 2 patients.Conclusion: The PBCL system is a safe and effective method to provide centering and corneal protection against mechanical trauma by the rigid lenses for keratoconus patients and may increase contact lens tolerance.Keywords: piggyback contact lens, keratoconus, irregular astigmatism

  12. Intraocular lens explantation or exchange: indications, postoperative interventions, and outcomes

    Directory of Open Access Journals (Sweden)

    Refik Oltulu

    2015-06-01

    Full Text Available ABSTRACT Purpose: To analyze the indications for explantation or exchange of intraocular lenses (IOLs, which were originally implanted for the correction of aphakia during cataract extraction. Methods: All cases that involved intraocular lens explantation or exchange in one institution between January 2008 and December 2014 were analyzed retrospectively. Results: In total, 93 eyes of 93 patients were analyzed. The median time interval between implantation and explantation of the anterior chamber intraocular lenses (AC IOL and posterior chamber intraocular lenses (PC IOL was 83.40 ± 83.14 months (range: 1-276 months and 55.14 ± 39.25 months (range: 1-168 months, respectively. Pseudophakic bullous keratopathy (17 eyes, 38.6% and persistent iritis (12 eyes, 27.8% in the AC IOL group and dislocation or decentration (30 eyes, 61.2% and incorrect IOL power (nine eyes, 18.4% in the PC IOL group were the most common indications for explantation of IOLs. The mean logMAR best corrected visual acuity (BCVA improved significantly from 1.30 preoperatively to 0.62 postoperatively in the PC IOL group (p<0.001 but did not improve significantly in the AC IOL group (p=0.186. Conclusions: The primary indication for IOL explantation or exchange was pseudophakic bullous keratopathy in the AC IOL group and was dislocation or decentration in the PC IOL group. PC IOL explantation or exchange is safe and improves visual acuity.

  13. Stochastic heterogeneity mapping around a Mediterranean salt lens

    Directory of Open Access Journals (Sweden)

    G. G. Buffett

    2010-01-01

    Full Text Available We present the first application of stochastic heterogeneity mapping based on the band-limited von Kármán function to a seismic reflection stack of a Mediterranean water eddy (meddy, a large salt lens of Mediterranean water. This process extracts two stochastic parameters directly from the reflectivity field of the seismic data: the Hurst number, which ranges from 0 to 1, and the correlation length (scale length. Lower Hurst numbers represent a richer range of scale lengths and correspond to a broader range of reflection events. The Hurst number estimate for the top of the meddy (0.39 compares well with recent theoretical work, which required values between 0.25 and 0.5 to model internal wave surfaces in open ocean conditions based on simulating a Garrett-Munk spectrum (GM76 slope of −2. Varying stochastic parameters, which correspond to different spectral slopes in the Garrett-Munk spectrum (horizontal wavenumber spectrum, can therefore provide an estimate of different internal wave scales from seismic data alone.

  14. Thermal behavior in the LENS process

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, M.L.; Schlienger, M.E.; Harwell, L.D. [and others

    1998-08-01

    Direct laser metal deposition processing is a promising manufacturing technology which could significantly impact the length of time between initial concept and finished part. For adoption of this technology in the manufacturing environment, further understanding is required to ensure robust components with appropriate properties are routinely fabricated. This requires a complete understanding of the thermal history during part fabrication and control of this behavior. This paper will describe research to understand the thermal behavior for the Laser Engineered Net Shaping (LENS) process, where a component is fabricated by focusing a laser beam onto a substrate to create a molten pool in which powder particles are simultaneously injected to build each layer. The substrate is moved beneath the laser beam to deposit a thin cross section, thereby creating the desired geometry for each layer. After deposition of each layer, the powder delivery nozzle and focusing lens assembly is incremented in the positive Z-direction, thereby building a three dimensional component layer additively. It is important to control the thermal behavior to reproducibly fabricate parts. The ultimate intent is to monitor the thermal signatures and to incorporate sensors and feedback algorithms to control part fabrication. With appropriate control, the geometric properties (accuracy, surface finish, low warpage) as well as the materials` properties (e.g., strength, ductility) of a component can be dialed into the part through the fabrication parameters. Thermal monitoring techniques will be described, and their particular benefits highlighted. Preliminary details in correlating thermal behavior with processing results will be discussed.

  15. Optimization of lens shape for autostereoscopic display

    Science.gov (United States)

    Su, Ping; An, Shu; Ma, Jianshe

    2016-10-01

    The three-dimensional(3D) displays based on binocular parallax have drawn increasingly interests. The light splitting element, which presents separate images to the viewer's left and right eyes, plays an important part in the auto-stereoscopic display. Lenticular lenses are widely used as the light splitting elements. However, the crosstalk resulted from the unsatisfied splitting may reduce the 3D experience. It was determined that the most suitable cross sectional shape for lenticular lenses is elliptical. Firstly, the formula of the surface is derived based on the ellipse expression and the requirement of the 3D display system, that is y2+0.5651x2 - 303.4768=0. Secondly, one axial source and 4 off-axial sources placed at the heights of 2.5mm, 5mm, 7.5mm and 8mm are used to analyze the beam splitting quality of the cylindrical and elliptical lens element, respectively. The spot of elliptical lens is smaller which means a better beam splitting quality. Thirdly, Monte Carlo Non-Sequential Ray tracing algorithm is used to simulate the luminance distribution on the viewing plane, the narrower width of vertical stripes means that the aberration is suppressed. Finally, the shape of elliptical can reduce the processing difficulty with the 10μm minimum step width. In a word, the optimization of the surface has a significant effect on the improvement of stereoscopic depth and the reduction of ghost images.

  16. What Do Gravitational Lens Time Delays Measure?

    CERN Document Server

    Kochanek, C S

    2002-01-01

    Gravitational lens time delays depend on the Hubble constant, the observed image positions, and the surface mass density of the lens in the annulus between the images. Simple time delay lenses like PG1115+080, SBS1520+530, B1600+434, PKS1830-211 and HE2149-2745 have H0 = A(1-)+B(e-1) where the two coefficients A ~ 90km/s Mpc and B ~ 10km/s Mpc depend on the measured delays and the observed image positions, is the mean surface density in the annulus between the images, and there is a small correction from the logarithmic slope e ~ 2 of the surface density profile, k ~ R^(1-e), in the annulus. These 5 systems are very homogeneous, since for fixed H0=100h km/s Mpc they must have the same surface density, =1.11-1.22 h +/- 0.04, with an upper bound of 0.07 on any dispersion in beyond those due to the measurement errors. If the lenses have their expected dark halos, ~ 0.5 and H0=51+/-5 km/s Mpc, while if they have constant mass-to-light ratios, ~ 0.1-0.2 and H0=73+/-8 km/s Mpc. More complicated lenses with mult...

  17. Curiosity's Mars Hand Lens Imager (MAHLI) Investigation

    Science.gov (United States)

    Edgett, Kenneth S.; Yingst, R. Aileen; Ravine, Michael A.; Caplinger, Michael A.; Maki, Justin N.; Ghaemi, F. Tony; Schaffner, Jacob A.; Bell, James F.; Edwards, Laurence J.; Herkenhoff, Kenneth E.; Heydari, Ezat; Kah, Linda C.; Lemmon, Mark T.; Minitti, Michelle E.; Olson, Timothy S.; Parker, Timothy J.; Rowland, Scott K.; Schieber, Juergen; Sullivan, Robert J.; Sumner, Dawn Y.; Thomas, Peter C.; Jensen, Elsa H.; Simmonds, John J.; Sengstacken, Aaron J.; Willson, Reg G.; Goetz, Walter

    2012-09-01

    The Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) investigation will use a 2-megapixel color camera with a focusable macro lens aboard the rover, Curiosity, to investigate the stratigraphy and grain-scale texture, structure, mineralogy, and morphology of geologic materials in northwestern Gale crater. Of particular interest is the stratigraphic record of a ˜5 km thick layered rock sequence exposed on the slopes of Aeolis Mons (also known as Mount Sharp). The instrument consists of three parts, a camera head mounted on the turret at the end of a robotic arm, an electronics and data storage assembly located inside the rover body, and a calibration target mounted on the robotic arm shoulder azimuth actuator housing. MAHLI can acquire in-focus images at working distances from ˜2.1 cm to infinity. At the minimum working distance, image pixel scale is ˜14 μm per pixel and very coarse silt grains can be resolved. At the working distance of the Mars Exploration Rover Microscopic Imager cameras aboard Spirit and Opportunity, MAHLI's resolution is comparable at ˜30 μm per pixel. Onboard capabilities include autofocus, auto-exposure, sub-framing, video imaging, Bayer pattern color interpolation, lossy and lossless compression, focus merging of up to 8 focus stack images, white light and longwave ultraviolet (365 nm) illumination of nearby subjects, and 8 gigabytes of non-volatile memory data storage.

  18. Tubular astigmatism-tunable fluidic lens.

    Science.gov (United States)

    Kopp, Daniel; Zappe, Hans

    2016-06-15

    We demonstrate a new means to fabricate three-dimensional liquid lenses which may be tuned in focal length and astigmatism. Using actuation by electrowetting-on-dielectrics, astigmatism in arbitrary directions may be tuned independently, with almost no cross talk between orthogonal orientations. The lens is based on electrodes structured on planar polyimide foils and subsequently rolled, enabling high-resolution patterning of complex electrodes along the azimuthal and radial directions of the lens. Based on a design established through fluidic and optical simulations, the astigmatism tuning is experimentally verified by a change of the corresponding Zernike coefficients measured using a Shack-Hartmann wavefront sensor. It was seen that the back focal length can be tuned by 5 mm and 0° and 45° astigmatism by 3 μm through application of voltages in the range of 50  Vrms. It was observed that the cross talk with other aberrations is very low, suggesting a novel means for astigmatism control in imaging systems.

  19. Radiation dose to the eye lens

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; D. Nielsen, Kamilla;

    2015-01-01

    field in oncology patients undergoing eyes-to-thighs PET/CT must always include the base of the scull according to department guidelines. The eye lens is sensitive to radiation exposure and if possible it should be avoided to scan the eye. If the patient’s head is kipped backwards during the scan one...... might avoid including the eye in the CT scan without losing sufficient visualization of the scull base. The aim of this study was to evaluate the possibility of decreasing the radiation dose to the eye lens, simply by changing the head position, when doing the PET/CT scan from the base of the scull...... pillow below the head (standard), and (b) kipped backwards with the pillow below the neck (kipped). For each head position, CT scans were repeated 5 times with both a low dose and a high dose CT protocol; in this way, a total of 20 CT scans were performed. Robust standard errors were used in order...

  20. Scleral lens for keratoconus: technology update

    Directory of Open Access Journals (Sweden)

    Rathi VM

    2015-10-01

    Full Text Available Varsha M Rathi,1 Preeji S Mandathara,2 Mukesh Taneja,1 Srikanth Dumpati,1 Virender S Sangwan1 1L V Prasad Eye Institute, Hyderabad, India; 2School of Optometry and Vision Science, University of New South Wales, Kensington, NSW, Australia Abstract: Scleral lenses are large diameter lenses which rest over the sclera, unlike the conventional contact lenses which rest on the cornea. These lenses are fitted to not touch the cornea and there is a space created between the cornea and the lens. These lenses are inserted in the eyes after filling with sterile isotonic fluid. Generally, scleral contact lenses are used for high irregular astigmatism as seen in various corneal ectatic diseases such as keratoconus, pellucid marginal degeneration, or/and as liquid bandage in ocular surface disorders. In this article, we review the new developments, that have taken place over the years, in the field of scleral contact lenses as regard to new designs, materials, manufacturing technologies, and fitting strategies particularly for keratoconus. Keywords: keratoconus, scleral lens, technology update, PROSE

  1. Calcification of intraocular implant lens surfaces.

    Science.gov (United States)

    Wu, Wenju; Guan, Xiangying; Tang, Ruikang; Hook, Daniel; Yan, Wenyan; Grobe, George; Nancollas, George H

    2004-02-17

    Calcification of octacalcium phosphate [Ca8H2(PO4)6 x 5H2O, OCP] on differently packaged "Ultem" and "Surefold" intraocular implant lens surfaces has been studied in vitro in solutions supersaturated with respect to OCP at pH = 7.10 and 37 degrees C. No mineral deposition was observed on the lenses packaged in Ultem vials even after treatment with behenic acid, one of the fatty acids identified on explanted lenses. Following treatment with behenic acid, nucleation of OCP occurred on the lenses from Surefold vials, which incorporate silicone gaskets; induction periods preceding calcification were about 6 h. No mineralization was found on the lenses in vials with other gasket materials, including polytetrafluoroethylene, fluorocarbon elastomer, and polypropylene. The results of this study indicate that both silicone and fatty acids such as behenic acid play important roles in inducing the in vivo calcification of OCP on IOL lenses; all of the lens treatment steps were necessary for nucleation induction.

  2. Curiosity's Mars Hand Lens Imager (MAHLI) Investigation

    Science.gov (United States)

    Edgett, Kenneth S.; Yingst, R. Aileen; Ravine, Michael A.; Caplinger, Michael A.; Maki, Justin N.; Ghaemi, F. Tony; Schaffner, Jacob A.; Bell, James F.; Edwards, Laurence J.; Herkenhoff, Kenneth E.; Heydari, Ezat; Kah, Linda C.; Lemmon, Mark T.; Minitti, Michelle E.; Olson, Timothy S.; Parker, Timothy J.; Rowland, Scott K.; Schieber, Juergen; Sullivan, Robert J.; Sumner, Dawn Y.; Thomas, Peter C.; Jensen, Elsa H.; Simmonds, John J.; Sengstacken, Aaron J.; Wilson, Reg G.; Goetz, Walter

    2012-01-01

    The Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) investigation will use a 2-megapixel color camera with a focusable macro lens aboard the rover, Curiosity, to investigate the stratigraphy and grain-scale texture, structure, mineralogy, and morphology of geologic materials in northwestern Gale crater. Of particular interest is the stratigraphic record of a ?5 km thick layered rock sequence exposed on the slopes of Aeolis Mons (also known as Mount Sharp). The instrument consists of three parts, a camera head mounted on the turret at the end of a robotic arm, an electronics and data storage assembly located inside the rover body, and a calibration target mounted on the robotic arm shoulder azimuth actuator housing. MAHLI can acquire in-focus images at working distances from ?2.1 cm to infinity. At the minimum working distance, image pixel scale is ?14 μm per pixel and very coarse silt grains can be resolved. At the working distance of the Mars Exploration Rover Microscopic Imager cameras aboard Spirit and Opportunity, MAHLI?s resolution is comparable at ?30 μm per pixel. Onboard capabilities include autofocus, auto-exposure, sub-framing, video imaging, Bayer pattern color interpolation, lossy and lossless compression, focus merging of up to 8 focus stack images, white light and longwave ultraviolet (365 nm) illumination of nearby subjects, and 8 gigabytes of non-volatile memory data storage.

  3. Lipid-protein interactions in plasma membranes of fiber cells isolated from the human eye lens.

    Science.gov (United States)

    Raguz, Marija; Mainali, Laxman; O'Brien, William J; Subczynski, Witold K

    2014-03-01

    The protein content in human lens membranes is extremely high, increases with age, and is higher in the nucleus as compared with the cortex, which should strongly affect the organization and properties of the lipid bilayer portion of intact membranes. To assess these effects, the intact cortical and nuclear fiber cell plasma membranes isolated from human lenses from 41- to 60-year-old donors were studied using electron paramagnetic resonance spin-labeling methods. Results were compared with those obtained for lens lipid membranes prepared from total lipid extracts from human eyes of the same age group [Mainali, L., Raguz, M., O'Brien, W. J., and Subczynski, W. K. (2013) Biochim. Biophys. Acta]. Differences were considered to be mainly due to the effect of membrane proteins. The lipid-bilayer portions of intact membranes were significantly less fluid than lipid bilayers of lens lipid membranes, prepared without proteins. The intact membranes were found to contain three distinct lipid environments termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain. However, the cholesterol bilayer domain, which was detected in cortical and nuclear lens lipid membranes, was not detected in intact membranes. The relative amounts of bulk and trapped lipids were evaluated. The amount of lipids in domains uniquely formed due to the presence of membrane proteins was greater in nuclear membranes than in cortical membranes. Thus, it is evident that the rigidity of nuclear membranes is greater than that of cortical membranes. Also the permeability coefficients for oxygen measured in domains of nuclear membranes were significantly lower than appropriate coefficients measured in cortical membranes. Relationships between the organization of lipids into lipid domains in fiber cells plasma membranes and the organization of membrane proteins are discussed.

  4. Solubility determination from clear points upon solvent addition

    NARCIS (Netherlands)

    Reus, M.A.; Heijden, A.E.D.M. van der; Horst, J.H. ter

    2015-01-01

    A method is described for determining the solubility of multicomponent crystalline compounds from clear points upon sample dilution at a constant temperature. Clear points are established by continuously adding a solvent mixture to a suspension of known composition until a clear solution appears. Fo

  5. Why are there so many system shapes in lens design?

    NARCIS (Netherlands)

    Bociort, F.

    2010-01-01

    The presence of many local minima in the merit function landscape is perhaps the most difficult challenge in lens design. We present a simplified mathematical model that illustrates why the number of local minima increases rapidly with each additional lens added to the imaging system. Comparisons wi

  6. The analysis of optical wave beams propagation in lens systems

    Science.gov (United States)

    Kazakov, I.; Mosentsov, S.; Moskaletz, O.

    2016-08-01

    In this paper some aspects of the formation and propagation of optical wave beams in lens systems were considered. As an example, the two-lens optical information processing system was considered. Analysis of the two-lens optical circuit has been made with a systems approach perspective. As part of the radio-optical analogies had been applied certain provisions of the theory of dynamical systems to the spatial optical system. The lens system is represented as a simple series-connected optical elements with known spatial impulse response. General impulse response of such a system has been received, as well as consider some special cases of the impulse response. The question of the relationship between the parameters and the size of the input aperture lenses for undistorted transmission of the optical signal has been considered. Analysis of the energy loss resulting from the finite aperture of the lens. It's based on an assessment of the fraction of radiation that propagates beyond the lens. Analysis showed that the energy losses depend explicitly on the following parameters: radiation wavelength, distance between input aperture and lens, and ratio of the input aperture and lens aperture. With the computer help simulation the dependence of losses was shown on the above parameters

  7. Opaque Contact Lens For Tracking Motion Of Eye

    Science.gov (United States)

    Zografos, James L., II; Gibson, Charles R.

    1993-01-01

    Opaque contact lens facilitates measurements of movements of eye; particularly, torsional movements. Lens, marked with pair of indices at diameter of 0.5 mm, provides stable, high-contrast reference for measurements of angular position and velocity of eye by use of video-image-analysis techniques. Intended for use in experiments on response of eye to vestibular balance mechanism.

  8. Terahertz wave tomographic imaging with a Fresnel lens

    Institute of Scientific and Technical Information of China (English)

    S. Wang; X.-C. Zhang

    2003-01-01

    We demonstrate three-dimensional tomographic imaging using a Fresnel lens with broadband terahertz pulses. Objects at various locations along the beam propagation path are uniquely imaged on the same imaging plane using a Fresnel lens with different frequencies of the imaging beam. This procedure allows the reconstruction of an object's tomographic contrast image by assembling the frequency-dependent images.

  9. Secondary implantation of a double intraocular lens after penetrating keratoplasty.

    Science.gov (United States)

    Gayton, J L

    1998-02-01

    Penetrating keratoplasty (PKP) patients often have severe, visually disabling refractive errors. Astigmatism can be addressed by refractive surgery; however, correcting hyperopia is more problematic. Although pseudophakic PKP patients can have a lens exchange, it can be traumatic in this population. In this pseudophakic PKP patient, I added a second posterior chamber intraocular lens, correcting the hyperopia and resolving visual complaints.

  10. An adjustable electron achromat for cathode lens microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tromp, R.M., E-mail: rtromp@us.ibm.com [IBM T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States); Leiden Institute of Physics, Kamerlingh Onnes Laboratory, Niels Bohrweg 2, 2333 CA Leiden (Netherlands)

    2015-12-15

    Chromatic aberration correction in light optics began with the invention of a two-color-corrected achromatic crown/flint lens doublet by Chester Moore Hall in 1730. Such color correction is necessary because any single glass shows dispersion (i.e. its index of refraction changes with wavelength), which can be counteracted by combining different glasses with different dispersions. In cathode lens microscopes (such as Photo Electron Emission Microscopy – PEEM) we encounter a similar situation, where the chromatic aberration coefficient of the cathode lens shows strong dispersion, i.e. depends (non-linearly) on the energy with which the electrons leave the sample. Here I show how a cathode lens in combination with an electron mirror can be configured as an adjustable electron achromat. The lens/mirror combination can be corrected at two electron energies by balancing the settings of the electron mirror against the settings of the cathode lens. The achromat can be adjusted to deliver optimum performance, depending on the requirements of a specific experiment. Going beyond the achromat, an apochromat would improve resolution and transmission by a very significant margin. I discuss the requirements and outlook for such a system, which for now remains a wish waiting for fulfilment. - Highlights: • The properties of cathode objective lens plus electron mirror are discussed. • In analogy with light-optical achromats, cathode lens plus mirror can be configured as an electron achromat. • Unlike light optics, the electron achromat can be adjusted to best fulfill experimental requirements.

  11. A Broadband Metasurface-Based Terahertz Flat-Lens Array

    KAUST Repository

    Wang, Qiu

    2015-02-12

    A metasurface-based terahertz flat-lens array is proposed, comprising C-shaped split-ring resonators exhibiting locally engineerable phase discontinuities. Possessing a high numerical aperture, the planar lens array is flexible, robust, and shows excellent focusing characteristics in a broadband terahertz frequency. It could be an important step towards the development of planar terahertz focusing devices for practical applications.

  12. Isofocusing and immunological investigations on cephalopod lens proteins

    NARCIS (Netherlands)

    Brahma, S.K.; Lancieri, M.

    1979-01-01

    Soluble lens proteins from Octopus vulgaris, Sepia officinalis, and Loligo vulgaris were analyzed by thin-layer isoelectric focusing and compared by various immunochemical methods using antibodies directed against total soluble lens protein antigens from the said three species. The results show clos

  13. Scleral lens tolerance after corneal cross-linking for keratoconus

    NARCIS (Netherlands)

    Visser, Esther Simone; Soeters, Nienke; Tahzib, Nayyirih G.

    2015-01-01

    Purpose. Subjective and objective evaluation of scleral lens tolerance and fitting before and after corneal cross-linking (CXL) for progressive keratoconus. Methods. In this prospective cohort, evaluations were made of 18 unilateral eyes in patients who underwent CXL and had been wearing scleral len

  14. Achromatic Fresnel Lens with Improved Efficiency for PV Systems

    Directory of Open Access Journals (Sweden)

    Mario González Montes

    2014-01-01

    Full Text Available This work is aimed to design and evaluate different achromatic Fresnel lens solutions capable of operating as concentrators aimed at photovoltaic cells systems. Throughout this study, the theoretical parametric design of the achromatic lens will be shown together with a series of simulations to verify the performance of each lens topology. The results will be compared with a standard Fresnel lens to ascertain the validity and effectiveness of the obtained design. Finally, a novel kind of hybrid lens is proposed, which combines the advantages of each type of lens (standard and Fresnel according to the optimal operating region of each design. Efficiency and concentration ratios of each particular lens are shown, regarding lens dimension, light’s incidence angle, or wavelength. Through this innovative achromatic design concentration ratios above 1000 suns, which hardly reach standard Fresnel lenses. Furthermore chromatic dispersion is minimized and the efficiency rate is over 85% of efficiency for a wide spectral range (from 350 nm to 1100 nm.

  15. Incidence of contact lens-associated microbial keratitis

    NARCIS (Netherlands)

    Cheng, K.H.; Leung, S.L.; Hoekman, J.W.; Beekhuis, W.H.; Mulder, P.G.H.; Geerards, A.J.M.; Kijlstra, A.

    1999-01-01

    Background. The incidence of contact-lens-associated microbial keratitis is uncertain and its related morbidity in the general population of contact-lens wearers is not known. We examined these issues in a prospective epidemiological study. Methods. We surveyed all practising ophthalmologists in the

  16. The NNEST lens non native english speakers in TESOL

    CERN Document Server

    Mahboob, Ahmar

    2010-01-01

    The NNEST Lens invites you to imagine how the field of TESOL and applied linguistics can develop if we use the multilingual, multicultural, and multinational perspectives of an NNEST lens to re-examine our assumptions, practices, and theories in the field

  17. Contact lens wear and dry eyes: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Markoulli M

    2017-02-01

    Full Text Available Maria Markoulli, Sailesh Kolanu School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia Abstract: The number of contact lens wearers worldwide has remained relatively stable over the past decade, despite the investment that has gone into contact lens technology. This is largely because 10%–50% of wearers dropout of contact lens wear within 3 years of commencement; the most common reason cited being contact lens discomfort (CLD. Of the symptoms reported, sensation of dry eye is the most common. Given the outcome of reduced wearing time, increased chair time, and ultimate contact lens discontinuation, the challenge is to identify the warning signs of CLD early on. Clinically detectable changes such as conjunctival staining, conjunctival indentation, conjunctival epithelial flap formation, lid wiper epitheliopathy, Demodex blepharitis, and meibomian gland dysfunction have been linked to CLD, highlighting the need to perform regular aftercare visits to identify these changes. At a cellular level, conjunctival metaplasia and reduced goblet cell density have been linked to CLD, leading to a downstream effect on the tear film breakup time of contact lens wearers. These factors suggest a strong link between CLD and friction, raising the need to target this as a means of minimizing CLD. The purpose of this review is to identify the clinical signs that relate to CLD as a means of earlier detection and management in order to combat contact lens dropout. Keywords: contact lens discomfort, dry eye disease, lid wiper epitheliopathy, tear film biomarkers, meibomian gland dysfunction

  18. The conformity of a soft contact lens on the eye.

    Science.gov (United States)

    Funkenbusch, G M; Benson, R C

    1996-08-01

    An axisymmetric elastic shell deformation model has been created to predict the conformity of a soft contact lens when pressed against the eye. Regions of contact and gap may be predicted, and the nonuniform reaction pressure between the lens and eye may also be found. This is important for issues like abrasion and comfort. Bending, membrane and transverse shear loads within the lens are also computed. Commercial soft contact lenses and a representative eye shape are used for the examples. We find that the uniformity of loading against the eye is strongly affected by the degree to which the lens is shaped to fit the eye, and relatively unaffected by the thickness of the lens.

  19. Dielectric Optical-Controlled Magnifying Lens by Nonlinear Negative Refraction

    CERN Document Server

    Cao, Jianjun; Zheng, Yuanlin; Chen, Xianfeng; Liang, Xiaogan; Wan, Wenjie

    2014-01-01

    A simple optical lens plays an important role for exploring the microscopic world in science and technology by refracting light with tailored spatially varying refractive index. Recent advancements in nanotechnology enable novel lenses, such as, superlens, hyperlens, Luneburg lens, with sub-wavelength resolution capabilities by specially designing materials' refractive indices with meta-materials and transformation optics. However, these artificially nano/micro engineered lenses usually suffer high losses from metals and are highly demanding in fabrication. Here we experimentally demonstrate for the first time a nonlinear dielectric magnifying lens using negative refraction by degenerate four-wave mixing in a plano-concave glass slide, obtaining magnified images. Moreover, we transform a nonlinear flat lens into a magnifying lens by introducing transformation optics into nonlinear regime, achieving an all-optical controllable lensing effect through nonlinear wave mixing, which may have many potential applicat...

  20. Patient acceptability of the Tecnis® multifocal intraocular lens

    Directory of Open Access Journals (Sweden)

    Sood P

    2011-03-01

    Full Text Available Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anterior prolate IOL with a diffractive multifocal lens design. The design aims to minimize spherical aberration and improve range of focus. The purpose of this review is to assess patient acceptability of the Tecnis® multifocal intraocular lens.Keywords: Tecnis®, intraocular lens, multifocal, presbyopia 

  1. Actively tunable plasmonic lens for subwavelength imaging at different wavelengths

    CERN Document Server

    Zeng, Beibei; Luo, Xiangang

    2011-01-01

    A type of tunable plasmonic lens with nanoslits is proposed for subwavelength imaging in the far field at different wavelengths. The nanoslits array in the plasmonic lens, which have constant depths but varying widths, could generate desired optical phase retardations based on the particular propagation property of the Surface Plasmon Polaritons (SPPs) in the metal-dielectric-metal (MDM) slit waveguides. We theoretically and numerically demonstrate the tunability of a single plasmonic lens for subwavelength imaging (full width at half maximum, 0.37 ~0.47) by adjusting the surrounding dielectric fluid, thereby realizing the compact in-plane tunable plasmonic lens. This work provides a novel approach for developing integrative tunable plasmonic lens for a variety of lab-on-chip applications.

  2. J0316+4328: a Probable "Asymmetric Double" Lens

    CERN Document Server

    Boyce, E R; Browne, I W A; Stroman, W J; Jackson, N J

    2007-01-01

    We report a probable gravitational lens J0316+4328, one of 19 candidate asymmetric double lenses (2 images at a high flux density ratio) from CLASS. Observations with the Very Large Array (VLA), MERLIN and the Very Long Baseline Array (VLBA) imply that J0316+4328 is a lens with high confidence. It has 2 images separated by 0.40", with 6 GHz flux densities of 62 mJy and 3.2 mJy. The flux density ratio of ~19 (constant over the frequency range 6-22 GHz) is the largest for any 2 image gravitational lens. High resolution optical imaging and deeper VLBI maps should confirm the lensing interpretation and provide inputs to detailed lens models. The unique configuration will give strong constraints on the lens galaxy's mass profile.

  3. Preliminary of Optical Lens Design for Micro-Satellite

    Science.gov (United States)

    Rachim, Elvira; Mukhtar Tahir, Andi; Herawan, Agus

    2017-01-01

    The development of micro satellites for the last two decades is emerging rapidly as the need of satellite communication usage is increasing. Earth observation is one of the example of how satellites are on demand. Most observation satellites consist of sensors and imaging system on-board. One of the key element to have a good imaging system is a special optical lens system design. Such lens is designed specifically by calculating every parameter such as refractive, reflective indexes, type of surface, distance and many more. Manufactured lenses sometimes do not match the requirement of an imager system hence the special lens design is needed. This paper will first briefly describe the history of optic, theory related to lens system, then the design and the analysis of lens system for micro-satellites generally and LAPAN A4 particularly.

  4. Gene expression profile of renal cell carcinoma clear cell type

    Directory of Open Access Journals (Sweden)

    Marcos F. Dall’Oglio

    2010-08-01

    Full Text Available PURPOSE: The determination of prognosis in patients with renal cell carcinoma (RCC is based, classically, on stage and histopathological aspects. The metastatic disease develops in one third of patients after surgery, even in localized tumors. There are few options for treating those patients, and even the new target designed drugs have shown low rates of success in controlling disease progression. Few studies used high throughput genomic analysis in renal cell carcinoma for determination of prognosis. This study is focused on the identification of gene expression signatures in tissues of low-risk, high-risk and metastatic RCC clear cell type (RCC-CCT. MATERIALS AND METHODS: We analyzed the expression of approximately 55,000 distinct transcripts using the Whole Genome microarray platform hybridized with RNA extracted from 19 patients submitted to surgery to treat RCC-CCT with different clinical outcomes. They were divided into three groups (1 low risk, characterized by pT1, Fuhrman grade 1 or 2, no microvascular invasion RCC; (2 high risk, pT2-3, Fuhrman grade 3 or 4 with, necrosis and microvascular invasion present and (3 metastatic RCC-CCT. Normal renal tissue was used as control. RESULTS: After comparison of differentially expressed genes among low-risk, high-risk and metastatic groups, we identified a group of common genes characterizing metastatic disease. Among them Interleukin-8 and Heat shock protein 70 were over-expressed in metastasis and validated by real-time polymerase chain reaction. CONCLUSION: These findings can be used as a starting point to generate molecular markers of RCC-CCT as well as a target for the development of innovative therapies.

  5. Cataract Surgery for Tilted Lens in Peters' Anomaly Type 2

    Directory of Open Access Journals (Sweden)

    Tadayuki Nishide

    2013-09-01

    Full Text Available Background: Cases of cataract surgery without penetrating keratoplasty in patients with Peters' anomaly are very rare. We report a case of Peters' anomaly type 2 with tilted lens due to synechia between the lens and iris that was treated with cataract surgery without penetrating keratoplasty. Case Presentation: A 16-year-old girl had Peters' anomaly in both eyes. Corneal opacity was severe in the left eye due to high-grade dysgenesis of the anterior segment. In the right eye, corneal opacity had spread from the center of the cornea to the inferotemporal side, and there was synechia between the iris and corneal endothelium from the inferonasal side to the inferotemporal side. Opacity was observed in the anterior pole of the lens, and there was synechia between the anterior iris and the lens. Ultrasound biomicroscopy (UBM revealed that the lens was tilted because of synechia. The tilted lens induced astigmatism, which reduced visual acuity to 20/250, in conjunction with a cataract. Cataract surgery was performed; the synechia between the lens capsule and the iris was severed, an intraocular lens was inserted, and the tilt was repaired. UBM was used postoperatively to confirm that the lens capsule synechia had been corrected and that the intraocular lens was not tilted. As a result, visual acuity improved to 20/100; glaucoma and expansion of corneal opacity were not observed. Conclusions: Severing of the synechia between the cataract and iris, during cataract surgery, in a patient with Peters' anomaly type 2 resulted in favorable postoperative visual acuity.

  6. Cosmic Lens Reveals Distant Galactic Violence

    Science.gov (United States)

    2008-10-01

    By cleverly unraveling the workings of a natural cosmic lens, astronomers have gained a rare glimpse of the violent assembly of a young galaxy in the early Universe. Their new picture suggests that the galaxy has collided with another, feeding a supermassive black hole and triggering a tremendous burst of star formation. Gravitational Lens Diagram Imaging a Distant Galaxy Using a Gravitational Lens CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for details and more graphics. The astronomers used the National Science Foundation's Very Large Array (VLA) radio telescope to look at a galaxy more than 12 billion light-years from Earth, seen as it was when the Universe was only about 15 percent of its current age. Between this galaxy and Earth lies another distant galaxy, so perfectly aligned along the line of sight that its gravity bends the light and radio waves from the farther object into a circle, or "Einstein Ring." This gravitational lens made it possible for the scientists to learn details of the young, distant galaxy that would have been unobtainable otherwise. "Nature provided us with a magnifying glass to peer into the workings of a nascent galaxy, providing an exciting look at the violent, messy process of building galaxies in the early history of the Universe," said Dominik Riechers, who led this project at the Max Planck Institute for Astronomy in Germany and now is a Hubble Fellow at the California Institute of Technology (Caltech). The new picture of the distant galaxy, dubbed PSS J2322+1944, shows a massive reservoir of gas, 16,000 light-years in diameter, that contains the raw material for building new stars. A supermassive black hole is voraciously eating material, and new stars are being born at the rate of nearly 700 Suns per year. By comparison, our Milky Way Galaxy produces the equivalent of about 3-4 Suns per year. The black hole appears to be near the edge, rather than at the center, of the giant gas reservoir, indicating, the astronomers say

  7. Bacterial transmission from lens storage cases to contact lenses - Effects of lens care solutions and silver impregnation of cases

    NARCIS (Netherlands)

    Vermeltfoort, Pit B. J.; Hooymans, Johanna M. M.; Busscher, Henk J.; van der Mei, Henny C.

    2008-01-01

    The killing efficacies of multipurpose lens care solutions on planktonic and biofilm bacteria grown in polypropylene contact lens storage cases with and without silver impregnation and effects on bacterial transmission from storage cases to silicone hydrogel contact lenses were investigated. For tra

  8. Force analysis of bacterial transmission from contact lens cases to corneas, with the contact lens as the intermediary

    NARCIS (Netherlands)

    Qu, Wen-wen; Hooymans, Johanna MM; de Vries, Jacob; van der Mei, Henderina; Busscher, Hendrik

    2011-01-01

    PURPOSE. To determine the probability of transmission of a Staphylococcus aureus strain from a contact lens case, to the contact lens (CL) surfaces, to the cornea, on the basis of bacterial adhesion forces measured by using atomic force microscopy (AFM). METHODS. Adhesion forces between S. aureus st

  9. The Sloan Lens ACS Survey. I. A large spectroscopically selected sample of massive early-type lens galaxies

    NARCIS (Netherlands)

    Bolton, AS; Burles, S; Koopmans, LVE; Treu, T; Moustakas, LA

    2006-01-01

    The Sloan Lens ACS (SLACS) Survey is an efficient Hubble Space Telescope (HST) Snapshot imaging survey for new galaxy-scale strong gravitational lenses. The targeted lens candidates are selected spectroscopically from the Sloan Digital Sky Survey (SDSS) database of galaxy spectra for having multiple

  10. Design and analysis of an adaptive lens that mimics the performance of the crystalline lens in the human eye

    Science.gov (United States)

    Santiago-Alvarado, Agustin; Cruz-Félix, Angel S.; Iturbide-Jiménez, F.; Martínez-López, M.; Ramírez-Como, M.; Armengol-Cruz, V.; Vásquez-Báez, I.

    2014-09-01

    Tunable lenses are optical systems that have attracted much attention due to their potential applications in such areas like ophthalmology, machine vision, microscopy and laser processing. In recent years we have been working in the analysis and performance of a liquid-filled variable focal length lens, this is a lens that can modify its focal length by changing the amount of water within it. Nowadays we extend our study to a particular adaptive lens known as solid elastic lens (SEL) that it is formed by an elastic main body made of Polydimethylsiloxane (PDMS Sylgard 184). In this work, we present the design, simulation and analysis of an adaptive solid elastic lens that in principle imitates the accommodation process of the crystalline lens in the human eye. For this work, we have adopted the parameters of the schematic eye model developed in 1985 by Navarro et al.; this model represents the anatomy of the eye as close as possible to reality by predicting an acceptable and accurate quantity of spherical and chromatic aberrations without any shape fitting. An opto-mechanical analysis of the accommodation process of the adaptive lens is presented, by simulating a certain amount of radial force applied onto the SEL using the finite element method with the commercial software SolidWorks®. We also present ray-trace diagrams of the simulated compression process of the adaptive lens using the commercial software OSLO®.

  11. AcrySof toric intraocular lens for post-keratoplasty astigmatism

    Directory of Open Access Journals (Sweden)

    Nishant Gupta

    2012-01-01

    Full Text Available We report a 63-year-old male who had undergone left eye optical penetrating keratoplasty for central leucomatous corneal opacity 10 years earlier. The eye had clear donor graft with residual astigmatism of −6.50 diopter cylinder (DC at 30°. The patient underwent clear corneal phacoemulsification with implantation of +6.0 D spherical equivalent AcrySof SN60T9 intraocular lens (IOL. Postoperatively, at 10 months, the patient had distance corrected visual acuity of 20/30 with −2.00 DC at 20°. AcrySof toric IOL offers an effective treatment option for post-keratoplasty high corneal astigmatism in patients with cataract.

  12. Simultaneous bilensectomy and endothelial keratoplasty for angle-supported phakic intraocular lens-induced corneal decompensation

    Directory of Open Access Journals (Sweden)

    Vikas Mittal

    2011-01-01

    Full Text Available A 40-year-old lady presented with severe endothelial cell loss in both eyes 14 years after angle-supported phakic intraocular lens (AS PIOL implantation. The left eye had severe corneal edema with bullous keratopathy. The right eye had markedly reduced endothelial cell count (655 cells/mm 2 although the cornea was clear. She underwent simultaneous bilensectomy (AS PIOL explantation and phacoemulsification and Descemet′s stripping and endothelial keratoplasty (DSEK in the left eye. Explanted AS PIOL was identified as ZSAL-4 (Morcher, Stuttgart, Germany model. Corneal edema cleared completely in 2 months with a best corrected visual acuity (-2.25 D sph of 20/60. No intervention was done in the right eye. The present case illustrates that AS PIOL-induced endothelial decompensation can be effectively managed by simultaneous bilensectomy and endothelial keratoplasty.

  13. TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. [Seoul National University Hospital (Korea, Republic of)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  14. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M. [Massachusetts General Hospital (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  15. Perubahan Sosial Berbasis Tasawuf: Studi Kasus Fethullah Gülen Dan Gülen Movement

    Directory of Open Access Journals (Sweden)

    Sulaiman Sulaiman

    2016-06-01

    Full Text Available Abstract: This article aims at analyzing Fethullah Gülen and the Gülen Movement which have succeeded in performing social change based on the teaching of Sufism. He did Sufism creativity in order that Sufism teaching was able to respond the changes that occur in the modernlife. He believed that, only by reinterpretation and contextualization of Sufism, the spiritual dimension of Islam would be able to perform the transformation or social change among the Muslims. Therefore, by using Max Weber’s theory of social action, this paper will analyze three key teachings of Sufism of Gülen: ascetic (zuhd, inbisat (expansion, and hizmet. Based on the Weber's theory, Gülen occupied a very central and authoritative position: agent/actor, action and meaning. As a source of meaning and interpreter of meaning, the key concepts of Sufism were transformed by Gülen to the internal and external communities so that they had made a move to do social movements and humanity. For the followers of Gülen, the movement was called the Gülen Movement or the Hizmet Movement which was engaged in the fields of education, health care, humanitarian assistance, and the mass media. All forms of movement were entirely based on the spiritual values of Islam that had been formulated by Gülen. الملخص: يهدف هذا البحث إلى تحليل شخصية فتح الله غولن وحركته الذي تمكن من القيام بالتغيير الاجتماعي على أساس التعاليم الصوفية. إن فتح الله غولن قام بإحياء التصوف في صورته الجدّية والحيوية في حياة الإنسان المعاصر. ويعتقد أن إعادة التفسير لتعاليم التصوف مع مراعاة الواقع قادرة على التغيير الاجتماعي بين المسلمين. من أجل ذلك، أن استخدام نظرية ويبر، يمكن تحليل تعاليم التصوف الثلاثة

  16. Global ballast water management and the "same location" concept: a clear term or a clear issue?

    Science.gov (United States)

    David, Matej; Gollasch, Stephan; Pavliha, Marko

    2013-03-01

    The United Nations recognized the transfer of harmful organisms and pathogens across natural barriers as one of the four greatest pressures to the world's oceans and seas, causing global environmental changes, while also posing a threat to human health, property, and resources. Ballast water transferred by vessels was recognized as a prominent vector of such species and was regulated by the International Convention for the Control and Management of Ship's Ballast Water and Sediments (2004). Permanent exceptions from ballast water management requirements may apply when the uptake and discharge of ballast water occur at the "same location." However, the "same location" concept may be interpreted differently, e.g., a port basin, a port, an anchorage, or a larger area even with more ports inside. Considering that the Convention is nearing the beginning of enforcement, national authorities all around the world will soon be exposed to applications for exceptions. Here we consider possible effects of different interpretations of the "same location" concept. We have considered different possible extensions of the same location through environmental, shipping, and legal aspects. The extension of such areas, and the inclusion of more ports, may compromise the Convention's main purpose. We recommend that "same location" mean the smallest practicable unit, i.e., the same harbor, mooring, or anchorage. An entire smaller port, possibly also including the anchorage, could be considered as same location. For larger ports with a gradient of environmental conditions, "same location" should mean a terminal or a port basin. We further recommend that IMO consider the preparation of a guidance document to include concepts, criteria, and processes outlining how to identify "same location," which limits should be clearly identified.

  17. CERN through the lens of Peter Ginter

    CERN Multimedia

    2008-01-01

    This summer, passers-by along the Quai Wilson on the banks of Lake Geneva will be able to enjoy an unusual exhibition of photographs devoted to CERN and the LHC. Fifty images from the work of Peter Ginter, organized into themes, give strollers on the Quai Wilson a glimpse of the unique human and scientific adventure at CERN. An exhibition panel, showing a scientist against the background of ALICE’s huge red electromagnet.CERN will reach an important milestone in 2008 with the start-up of the LHC, opening a new window on our Universe for physicists around the world. To celebrate this event with the people who live around Lake Geneva and visitors to the area, CERN and the city of Geneva are jointly putting on the photography exhibition "CERN through the lens of Peter Ginter", which opens on 29 May. A group of some fifty images taken by the German photo...

  18. Hyperbolic metamaterial lens with hydrodynamic nonlocal response

    DEFF Research Database (Denmark)

    Yan, Wei; Mortensen, N. Asger; Wubs, Martijn

    2013-01-01

    in the local-response approximation and in the hydrodynamic Drude model can differ considerably. In particular, the optimal frequency for imaging in the nonlocal theory is blueshifted with respect to that in the local theory. Thus, to detect whether nonlocal response is at work in a hyperbolic metamaterial, we......We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves...... of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion curves numerically. As an application, we find that the focusing characteristics of a HMM lens...

  19. Achromatic Metasurface Lens at Telecommunication Wavelengths.

    Science.gov (United States)

    Khorasaninejad, Mohammadreza; Aieta, Francesco; Kanhaiya, Pritpal; Kats, Mikhail A; Genevet, Patrice; Rousso, David; Capasso, Federico

    2015-08-12

    Nanoscale optical resonators enable a new class of flat optical components called metasurfaces. This approach has been used to demonstrate functionalities such as focusing free of monochromatic aberrations (i.e., spherical and coma), anomalous reflection, and large circular dichroism. Recently, dielectric metasurfaces that compensate the phase dispersion responsible for chromatic aberrations have been demonstrated. Here, we utilize an aperiodic array of coupled dielectric nanoresonators to demonstrate a multiwavelength achromatic lens. The focal length remains unchanged for three wavelengths in the near-infrared region (1300, 1550, and 1800 nm). Experimental results are in agreement with full-wave simulations. Our findings are an essential step toward a realization of broadband flat optical elements.

  20. Intraocular lens employed for cataract surgery

    Science.gov (United States)

    Roszkowska, A. M.; Torrisi, L.

    2014-04-01

    The aim of this paper is to illustrate the techniques of cataract surgery with implantation of intraocular lenses and some physical properties of the used materials. The new technology, coupled with extensive experience and the studied cases, permits to increase the standardization and accuracy of the engravings, by reducing the use and handling of surgical instruments inside the eye. At present it is possible to replace the cataract with crystalline lenses based on biopolymers such as PMMA, silicone, acrylic hydrophilic and hydrophobic acrylic. These materials are increasingly able to replace the natural lens and to ensure the fully functional of the eye. The role of femtosecond lasers in cataract surgery, to assist or replace several aspects of the manual cataract surgery, are discussed.

  1. Photochromic lens mirror-coated with Cr

    Science.gov (United States)

    Shin, Sungho; Lee, Myeongkyu

    2007-11-01

    We have designed and fabricated mirror-coated photochromic lenses for use in sunglasses. These lenses consisted of a Cr thin film sandwiched between two SiO2 layers on the front surface and an anti-reflection (AR) coating on the backside. The SiO2 films above and below the Cr layer were introduced as the protection and buffer layers, respectively. The AR coating was to suppress back-reflection from the lens surface. Deposition of all coating layers were carried out by an e-beam evaporator under Ar atmosphere at P = 10-5 Torr and T = 70 °C. As expected, the overall transmittance decreased with increasing Cr thickness. For a Cr layer of 5 nm thickness, it changed from about 45% in the bleached state down to 25% after exposure to sunlight. This is consistent with the transmission range typically required for sunglasses.

  2. Gravitational Lens Recovery with GLASS: Measuring the mass profile and shape of a lens

    CERN Document Server

    Coles, Jonathan P; Saha, Prasenjit

    2014-01-01

    We use a new non-parametric gravitational modelling tool -- GLASS -- to determine what quality of data (strong lensing, stellar kinematics, and/or stellar masses) are required to measure the circularly averaged mass profile of a lens and its shape. GLASS uses an under-constrained adaptive grid of mass pixels to model the lens, searching through thousands of models to marginalise over model uncertainties. Our key findings are as follows: (i) for pure lens data, multiple sources with wide redshift separation give the strongest constraints as this breaks the well-known mass-sheet or steepness degeneracy; (ii) a single quad with time delays also performs well, giving a good recovery of both the mass profile and its shape; (iii) stellar masses -- for lenses where the stars dominate the central potential -- can also break the steepness degeneracy, giving a recovery for doubles almost as good as having a quad with time delay data, or multiple source redshifts; (iv) stellar kinematics provide a robust measure of the ...

  3. Aspherical Lens Design Using Genetic Algorithm for Reducing Aberrations in Multifocal Artificial Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Chih-Ta Yen

    2015-09-01

    Full Text Available A complex intraocular lens (IOL design involving numerous uncertain variables is proposed. We integrated a genetic algorithm (GA with the commercial optical design software of (CODE V to design a multifocal IOL for the human eye. We mainly used an aspherical lens in the initial state to the crystalline type; therefore, we used the internal human eye model in the software. The proposed optimized algorithm employs a GA method for optimally simulating the focusing function of the human eye; in this method, the thickness and curvature of the anterior lens and the posterior part of the IOL were varied. A comparison of the proposed GA-designed IOLs and those designed using a CODE V built-in optimal algorithm for 550 degrees myopia and 175 degrees astigmatism conditions of the human eye for pupil size 6 mm showed that the proposed IOL design improved the spot size of root mean square (RMS, tangential coma (TCO and modulation transfer function (MTF at a spatial frequency of 30 with a pupil size of 6 mm by approximately 17%, 43% and 35%, respectively. However, the worst performance of spherical aberration (SA was lower than 46%, because the optical design involves a tradeoff between all aberrations. Compared with the traditional CODE V built-in optimal scheme, the proposed IOL design can efficiently improve the critical parameters, namely TCO, RMS, and MTF.

  4. Contrast sensitivity after refractive lens exchange with a multifocal diffractive aspheric intraocular lens

    Directory of Open Access Journals (Sweden)

    Teresa Ferrer-Blasco

    2013-04-01

    Full Text Available PURPOSE: To evaluate distance and near contrast sensitivity (CS under photopic and mesopic conditions before and after refractive lens exchange (RLE and implantation of the aspheric AcrySof®ReSTOR® (SN6AD3 model intraocular lens (IOL. METHODS:Seventy-four eyes of 37 patients after RLE underwent bilateral implantation with the aspheric AcrySof ReSTOR IOL. The patient sample was divided into myopic and hyperopic groups. Monocular uncorrected visual acuity at distance and near (UCVA and UCNVA, respectively and monocular best corrected visual acuity at distance and near (BCVA and BCNVA, respectively were measured before and 6 months postoperatively. Monocular CS function was measured at three different luminance levels (85, 5 and 2.5 cd/m² before and after RLE. Post-implantation results at 6 months were compared with those found before surgery. RESULTS: Our results revealed that patients in both groups obtained good UCVA and BCVA after RLE at distance and near vision in relation to pre-surgery values. No statistically significant differences were found between the values of CS pre and post-RLE at distance and near, at any lighting condition and spatial frequency (p>0.002. CONCLUSIONS: Refractive lens exchange with aspheric AcrySof ReSTOR IOL in myopic and hyperopic population provided good visual function and yield good distance and near CS under photopic and mesopic conditions.

  5. Spectral analysis and comparison of mineral deposits forming in opacified intraocular lens and senile cataractous lens

    Science.gov (United States)

    Lin, Shan-Yang; Chen, Ko-Hwa; Lin, Chih-Cheng; Cheng, Wen-Ting; Li, Mei-Jane

    2010-10-01

    This preliminary report was attempted to compare the chemical components of mineral deposits on the surfaces of an opacified intraocular lens (IOL) and a calcified senile cataractous lens (SCL) by vibrational spectral diagnosis. An opacified intraocular lens (IOL) was obtained from a 65-year-old male patient who had a significant decrease in visual acuity 2-years after an ocular IOL implantation. Another SCL with grayish white calcified plaque on the subcapsular cortex was isolated from a 79-year-old male patient with complicated cataract after cataract surgery. Optical light microscope was used to observe both samples and gross pictures were taken. Fourier transform infrared (FT-IR) and Raman microspectroscopic techniques were employed to analyze the calcified deposits. The curve-fitting algorithm using the Gaussian function was also used to quantitatively estimate the chemical components in each deposit. The preliminary results of spectral diagnosis indicate that the opacified IOL mainly consisted of the poorly crystalline, immature non-stoichiometric hydroxyapatite (HA) with higher content of type B carbonated apatites. However, the calcified plaque deposited on the SCL was comprised of a mature crystalline stoichiometric HA having higher contents of type A and type B carbonate apatites. More case studies should be examined in future.

  6. Solar lens mission concept for interstellar exploration

    Science.gov (United States)

    Brashears, Travis; Lubin, Philip; Turyshev, Slava; Shao, Michael; Zhang, Qicheng

    2015-09-01

    The long standing approach to space travel has been to incorporate massive on-board electronics, probes and propellants to achieve space exploration. This approach has led to many great achievements in science, but will never help to explore the interstellar medium. Fortunately, a paradigm shift is upon us in how a spacecraft is constructed and propelled. This paper describes a mission concept to get to our Sun's Gravity Lens at 550AU in less than 10 years. It will be done by using DE-STAR, a scalable solar-powered phased-array laser in Earth Orbit, as a directed energy photon drive of low-mass wafersats. [1] [2] [3] [4] [5] With recent technologies a complete mission can be placed on a wafer including, power from an embedded radio nuclear thermal generator (RTG), PV, laser communications, imaging, photon thrusters for attitude control and other sensors. As one example, a futuristic 200 MW laser array consisting of 1 - 10 kw meter scale sub elements with a 100m baseline can propel a 10 gram wafer scale spacecraft with a 3m laser sail to 60AU/Year. Directed energy propulsion of low-mass spacecraft gives us an opportunity to capture images of Alpha Centauri and its planets, detailed imaging of the cosmic microwave background, set up interstellar communications by using gravity lenses around nearby stars to boost signals from interstellar probes, and much more. This system offers a very large range of missions allowing hundreds of wafer scale payload launches per day to reach this cosmological data reservoir. Directed Energy Propulsion is the only current technology that can provide a near-term path to utilize our Sun's Gravity Lens.

  7. Thermal optical path difference analysis of off-axis lens ray trace foot-print at Cassegrain telescope correct lens assembly

    Science.gov (United States)

    Hsu, Ming-Ying; Lin, Yu-Chuan; Chan, Chia-Yen; Lin, Wei-Cheng; Chan, Shenq-Tsong; Huang, Ting-Ming

    2012-10-01

    The Cassegrain telescope system in this study, is discussion correct lens thermal OPD (Optical Path Difference) effect optical performance. The correct lens assembly are includes several components such as correct lens, lens mount, spacer, mount barrel and retainer. The heat transfer from surrounding to the correct lens barrel will causes optical system aberration. Meanwhile, the off-axis rays path of the OPD must consider lens incidence point and emergence point. The correct lens temperature distribution is calculate the lens barrel heat transfer analysis, the thermal distortion and stress are solve by FEM (Finite Element Method) software. The temperature calculation results can be weighting to each incidence ray path and calculate thermal OPD. The thermal OPD on Z-direction can be fitted by rigid body motion and Zernike polynomial. The fitting results can be used to evaluate the thermal effect on correct lens assembly in telescope system.

  8. Conduta cirúrgica na subluxação do cristalino Surgical approach to the subluxated lens

    Directory of Open Access Journals (Sweden)

    Nórton Souto Severo

    2004-02-01

    Full Text Available OBJETIVO: Apresentar 10 casos de subluxação de cristalino, secundários a trauma ou a síndrome de Marfan, discutindo o tratamento e os resultados obtidos. MÉTODOS: Foram estudados 10 olhos de 9 pacientes, 6 casos secundários a trauma contuso e 4 casos a síndrome de Marfan. A idade média foi de 48,9 ± 18,2 anos, com tempo de seguimento de 34,6 ± 11,6 meses (12 a 62 meses. Os pacientes foram submetidos à facectomia intracapsular (1 caso, extracapsular com capsulorrexe (1 caso, facoemulsificação sem LIO (1 caso, e facoemulsificação com implante de LIO (7 casos. Anéis expansores capsulares foram utilizados em 7 olhos. RESULTADOS: Houve melhora da acuidade visual em todos os casos durante o seguimento, exceto em um, em que houve descolamento de retina, 20 dias após o procedimento. CONCLUSÃO: A facectomia com implante de LIO em pacientes com cristalino subluxado é procedimento viável, principalmente com a facoemulsificação e o uso do anel expansor capsular, podendo melhorar bastante a acuidade visual e a qualidade de vida desses pacientes.PURPOSE: To evaluate 10 cases of subluxated lens due to trauma or Marfan syndrome, focussing on their treatment and the results. METHODS: Ten eyes of 9 patients were operated on due to lens subluxation. Six eyes were due to trauma and 4 eyes to Marfan syndrome. The mean age was 48.9 ± 18.2 years, and the follow-up period of 34.6 ± 11.6 months. Patients were submitted to intracapsular lens extraction (1 eye, extracapsular lens extraction (1 eye, phacoemulsification without IOL (1 eye, and phacoemulsification with IOL (7 eyes. Endocapsular rings were used in 7 eyes. RESULTS: Best-corrected visual acuity improved in all patients, except for one, who had a regmatogeneous retinal detachment, 20 days after surgery. CONCLUSION: Lens extraction with IOL implantation in subluxated lens patients has a good prognosis, especially with pha-coemulsification and endocapsular rings. With this approach, we were

  9. Flavin nucleotides in human lens: regional distribution in brunescent cataracts.

    Science.gov (United States)

    Bhat, K S; Nayak, S

    1998-12-01

    The biochemical mechanism(s) underlying brunescent cataracts remain unclear. Oxidative stress due to reactive oxygen species may have a role in the pigmentation process in eye lens. We have analysed human cataractous lenses for flavins by high-performance liquid chromatography (HPLC), since flavins are light sensitive and act as endogenous sensitizers generating reactive oxygen species in the eye. The most significant observation in this study is that higher levels of flavin nucleotides occur in brown lens compared to yellow lens. The concentration of flavin nucleotides (flavin monouncleotide, FMN + flavin adenine dinucleotide, FAD) was highest in the nuclear region of the lens followed by the cortical and capsule-epithelial regions. However, the ratio of FAD/FMN was lowest in the nuclear region of the lens followed by other regions. On the other hand, riboflavin was not detected in any of the lens (cataractous) regions. These results suggest that the observed increase in flavin nucleotides in the ocular tissue could contribute towards deepening of lens pigmentation.

  10. Fgf19 is required for zebrafish lens and retina development.

    Science.gov (United States)

    Nakayama, Yoshiaki; Miyake, Ayumi; Nakagawa, Yu; Mido, Tomotaka; Yoshikawa, Maya; Konishi, Morichika; Itoh, Nobuyuki

    2008-01-15

    Fgf signaling plays crucial roles in morphogenesis. Fgf19 is required for zebrafish forebrain development. Here, we examined the roles of Fgf19 in the formation of the lens and retina in zebrafish. Knockdown of Fgf19 caused a size reduction of the lens and the retina, failure of closure of the choroids fissure, and a progressive expansion of the retinal tissue to the midline of the forebrain. Fgf19 expressed in the nasal retina and lens was involved in cell survival but not cell proliferation during embryonic lens and retina development. Fgf19 was essential for the differentiation of lens fiber cells in the lens but not for the neuronal differentiation and lamination in the retina. Loss of nasal fate in the retina caused by the knockdown of Fgf19, expansion of nasal fate in the retina caused by the overexpression of Fgf19 and eye transplantation indicated that Fgf19 in the retina was crucial for the nasal-temporal patterning of the retina that is critical for the guidance of retinal ganglion cell axons. Knockdown of Fgf19 also caused incorrect axon pathfinding. The present findings indicate that Fgf19 positively regulates the patterning and growth of the retina, and the differentiation and growth of the lens in zebrafish.

  11. MALDI-MS-imaging of whole human lens capsule.

    Science.gov (United States)

    Ronci, Maurizio; Sharma, Shiwani; Chataway, Tim; Burdon, Kathryn P; Martin, Sarah; Craig, Jamie E; Voelcker, Nicolas H

    2011-08-05

    The ocular lens capsule is a smooth, transparent basement membrane that encapsulates the lens and is composed of a rigid network of interacting structural proteins and glycosaminoglycans. During cataract surgery, the anterior lens capsule is routinely removed in the form of a circular disk. We considered that the excised capsule could be easily prepared for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-MSI) analysis. MALDI-MSI is a powerful tool to elucidate the spatial distribution of small molecules, peptides, and proteins within tissues. Here, we apply this molecular imaging technique to analyze the freshly excised human lens capsule en face. We demonstrate that novel information about the distribution of proteins by MALDI-MSI can be obtained from this highly compact connective tissue, having no evident histo-morphological characteristics. Trypsin digestion carried out on-tissue is shown to improve MALDI-MSI analysis of human lens capsules and affords high repeatability. Most importantly, MALDI-MSI analysis reveals a concentric distribution pattern of proteins such as apolipoprotein E (ApoE) and collagen IV alpha-1 on the anterior surface of surgically removed lens capsule, which may indicate direct or indirect effects of environmental and mechanical stresses on the human ocular lens.

  12. Numerical implementation of generalized Coddington equations for ophthalmic lens design

    Science.gov (United States)

    Rojo, P.; Royo, S.; Ramírez, J.; Madariaga, I.

    2014-02-01

    A method for general implementation in any software platform of the generalized Coddington equations is presented, developed, and validated within a Matlab environment. The ophthalmic lens design strategy is presented thoroughly, and the basic concepts of generalized ray tracing are introduced. The methodology for ray tracing is shown to include two inter-related processes. Firstly, finite ray tracing is used to provide the main direction of propagation of the considered ray at the incidence point of interest. Afterwards, generalized ray tracing provides the principal curvatures of the local wavefront at that point, and its orientation after being refracted by the lens. The curvature values of the local wavefront are interpreted as the sagital and tangential powers of the lens at the point of interest. The proposed approach is validated using a double-check of the calculated lens performance in the spherical lens case: while finite ray tracing is validated using a commercial ray tracing software, generalized ray tracing is validated using a software application for ophthalmic lens design based on the classical version of Coddington equations. Equations of the complete tracing process are developed in detail for the case of generic astigmatic ophthalmic lenses as an example. Three-dimensional representation of the sagital and tangential powers of the ophthalmic lens at all directions of gaze then becomes possible, and results are presented for lenses with different geometries.

  13. Finite Element Analysis of the LOLA Receiver Telescope Lens

    Science.gov (United States)

    Matzinger, Elizabeth

    2007-01-01

    This paper presents the finite element stress and distortion analysis completed on the Receiver Telescope lens of the Lunar Orbiter Laser Altimeter (LOLA). LOLA is one of six instruments on the Lunar Reconnaissance Orbiter (LRO), scheduled to launch in 2008. LOLA's main objective is to produce a high-resolution global lunar topographic model to aid in safe landings and enhance surface mobility in future exploration missions. The Receiver Telescope captures the laser pulses transmitted through a diffractive optical element (DOE) and reflected off the lunar surface. The largest lens of the Receiver Telescope, Lens 1, is a 150 mm diameter aspheric lens originally designed to be made of BK7 glass. The finite element model of the Receiver Telescope Lens 1 is comprised of solid elements and constrained in a manner consistent with the behavior of the mounting configuration of the Receiver Telescope tube. Twenty-one temperature load cases were mapped to the nodes based on thermal analysis completed by LOLA's lead thermal analyst, and loads were applied to simulate the preload applied from the ring flexure. The thermal environment of the baseline design (uncoated BK7 lens with no baffle) produces large radial and axial gradients in the lens. These large gradients create internal stresses that may lead to part failure, as well as significant bending that degrades optical performance. The high stresses and large distortions shown in the analysis precipitated a design change from BK7 glass to sapphire.

  14. c-Myc regulates cell proliferation during lens development.

    Directory of Open Access Journals (Sweden)

    Gabriel R Cavalheiro

    Full Text Available Myc protooncogenes play important roles in the regulation of cell proliferation, growth, differentiation and survival during development. In various developing organs, c-myc has been shown to control the expression of cell cycle regulators and its misregulated expression is detected in many human tumors. Here, we show that c-myc gene (Myc is highly expressed in developing mouse lens. Targeted deletion of c-myc gene from head surface ectoderm dramatically impaired ocular organogenesis, resulting in severe microphtalmia, defective anterior segment development, formation of a lens stalk and/or aphakia. In particular, lenses lacking c-myc presented thinner epithelial cell layer and growth impairment that was detectable soon after its inactivation. Defective development of c-myc-null lens was not caused by increased cell death of lens progenitor cells. Instead, c-myc loss reduced cell proliferation, what was associated with an ectopic expression of Prox1 and p27(Kip1 proteins within epithelial cells. Interestingly, a sharp decrease in the expression of the forkhead box transcription factor Foxe3 was also observed following c-myc inactivation. These data represent the first description of the physiological roles played by a Myc family member in mouse lens development. Our findings support the conclusion that c-myc regulates the proliferation of lens epithelial cells in vivo and may, directly or indirectly, modulate the expression of classical cell cycle regulators in developing mouse lens.

  15. Optimized optical clearing method for imaging central nervous system

    Science.gov (United States)

    Yu, Tingting; Qi, Yisong; Gong, Hui; Luo, Qingming; Zhu, Dan

    2015-03-01

    The development of various optical clearing methods provides a great potential for imaging entire central nervous system by combining with multiple-labelling and microscopic imaging techniques. These methods had made certain clearing contributions with respective weaknesses, including tissue deformation, fluorescence quenching, execution complexity and antibody penetration limitation that makes immunostaining of tissue blocks difficult. The passive clarity technique (PACT) bypasses those problems and clears the samples with simple implementation, excellent transparency with fine fluorescence retention, but the passive tissue clearing method needs too long time. In this study, we not only accelerate the clearing speed of brain blocks but also preserve GFP fluorescence well by screening an optimal clearing temperature. The selection of proper temperature will make PACT more applicable, which evidently broaden the application range of this method.

  16. Test results of high-precision large cryogenic lens holders

    Science.gov (United States)

    Gal, C.; Reutlinger, A.; Boesz, A.; Leberle, T.; Mottaghibonab, A.; Eckert, P.; Dubowy, M.; Gebler, H.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

    2012-09-01

    For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system [1]. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision large lens holders (?170 mm) at cryogenic temperatures (150K). The four lenses of the optical system are made of different materials: fused silica, CaF2, and LF5G15 that are mounted in a separate lens barrel design. Each lens has its separate mechanical interface to the lens barrel, the so called adaption ring. The performance of the lens holder design is verified by adapted test equipment and test facility including an optical metrology system. The characterization of the lens deformation and displacement (decenter, tilt) due to mechanical loads of the holder itself as well as thermally induced loads are driven by the required submicron precision range and the operational thermal condition. The surface deformation of the lens and its holder is verified by interferometric measurements, while tilt and position accuracy are measured by in-situ fibre based distance sensors. The selected distance measurement sensors have the capability to measure in a few mm range with submicron resolution in ultra high vacuum, in vibration environments and at liquid nitrogen temperatures and below. The calibration of the measurement system is of crucial importance: impacts such as temperature fluctuation, surface roughness, surface reflectivity, straylight effects, etc. on the measured distance are carefully calibrated. Inbuilt thermal expansion effects of the fibre sensors are characterized and proven with lens dummy with quasi zero CTE. The paper presents the test results and measured performance of the high precision large cryogenic lens holders attained by the metrology system. These results are presented on behalf of the EUCLID consortium.

  17. Critical Assessment of Correction Methods for Fisheye Lens Distortion

    Science.gov (United States)

    Liu, Y.; Tian, C.; Huang, Y.

    2016-06-01

    A fisheye lens is widely used to create a wide panoramic or hemispherical image. It is an ultra wide-angle lens that produces strong visual distortion. The distortion modeling and estimation of the fisheye lens are the crucial step for fisheye lens calibration and image rectification in computer vision and close-range photography. There are two kinds of distortion: radial and tangential distortion. Radial distortion is large for fisheye imaging and critical for the subsequent image processing. Although many researchers have developed calibration algorithms of radial distortion of fisheye lens, quantitative evaluation of the correction performance has remained a challenge. This is the first paper that intuitively and objectively evaluates the performance of five different calibration algorithms. Upto- date research on fisheye lens calibration is comprehensively reviewed to identify the research need. To differentiate their performance in terms of precision and ease-using, five methods are then tested using a diverse set of actual images of the checkerboard that are taken at Wuhan University, China under varying lighting conditions, shadows, and shooting angles. The method of rational function model, which was generally used for wide-angle lens correction, outperforms the other methods. However, the one parameter division model is easy for practical use without compromising too much the precision. The reason is that it depends on the linear structure in the image and requires no preceding calibration. It is a tradeoff between correction precision and ease-using. By critically assessing the strengths and limitations of the existing algorithms, the paper provides valuable insight and guideline for future practice and algorithm development that are important for fisheye lens calibration. It is promising for the optimal design of lens correction models that are suitable for the millions of portable imaging devices.

  18. Effects of x-irradiation on lens reducing systems. [Rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Giblin, F.J.; Chakrapani, B.; Reddy, V.N.

    1978-01-01

    Studies have been made of the effects of x ray on various lens reducing systems including the levels of NADPH and glutathione (GSH), the activity of the hexose monophosphate shunt (HMS), and the activities of certain enzymes including glutathion reductase, glutathione peroxidase, and glucose-6-phosphate dehydrogenase (G-6-PD). It was found that during several weeks following x irradiation but prior to cataract formation there was very little change in the number of reduced -SH groups per unit weight of lens protein but that, with the appearance of cataract, there was a sudden loss of protein -SH groups. In contrast, the concentration of GSH in the x-rayed lens decreased throughout the experimental period. Similarly, the concentration of NADPH in the x-rayed lens was found to decrease significantly relative to controls one week prior to cataract formation and the ratio of NADPH to NADP/sup +/ in the lens shifted at this time period from a value greater than 1.0 in the control lens to less than 1.0 in the x-rayed lens. A corresponding decrease occurred in the activity of the HMS in x-rayed lenses as measured by culture in the presence of 1-/sup 14/C-labelled glucose. G-6-PD was partially inactivated in the x-rayed lens. Of the eight enzymes studied, G-6-PD appeared to be the most sensitive to x-irradiation. The data indicate that x-irradiation results in a steady decrease in the effectiveness of lens reducing systems and that, when these systems reach a critically low point, sudden oxidation of protein -SH groups and formation of high molecular weight protein aggregates may be initiated.

  19. A magnetized Einzel lens electron dump for the Linac4 H− ion source

    CERN Document Server

    Midttun, O; Kronberger, M; Lettry, J; Pereira, H; Scrivens, R

    2013-01-01

    Linac4 is a 160 MeV linear accelerator which will inject negative hydrogen ions (H−) into CERN’s Proton Synchrotron Booster, a required upgrade to improve the beam brightness in the LHC injector chain. A volume production RF ion source, based on the design of the DESY RF source was implemented, but showed considerable electron dump ablation during operation at 45 keV beam energy. To reduce the electron beam power density in the dump, a magnetized Einzel lens is designed that reduces the beam energy to 10 keV before permanentmagnets dump the electrons on a tungsten surface. Presented in this paper are simulations of the design using IBSimu, the tunable range of parameters depending on the extracted H− and electron current, as well as details of the implementation, the choice of pulsed power converters and the electrode alignment system. In addition, simulations of proton extraction from this source will be shown.

  20. Evolutionary algorithm for optimization of nonimaging Fresnel lens geometry.

    Science.gov (United States)

    Yamada, N; Nishikawa, T

    2010-06-21

    In this study, an evolutionary algorithm (EA), which consists of genetic and immune algorithms, is introduced to design the optical geometry of a nonimaging Fresnel lens; this lens generates the uniform flux concentration required for a photovoltaic cell. Herein, a design procedure that incorporates a ray-tracing technique in the EA is described, and the validity of the design is demonstrated. The results show that the EA automatically generated a unique geometry of the Fresnel lens; the use of this geometry resulted in better uniform flux concentration with high optical efficiency.

  1. Comparison of shape recovery ratios in various intraocular lens haptics.

    Science.gov (United States)

    Kimura, W; Kimura, T; Sawada, T; Kikuchi, T; Toda, H; Yamada, Y; Nagai, H

    1992-11-01

    Since understanding the mechanical properties of intraocular lens (IOL) haptic materials can minimize decentration after surgery, we have examined shape recovery ratios of various intraocular lens haptics (polypropylene [PP], polyvinylidene fluoride [PVDF], extruded poly(methyl methacrylate) [PMMA]) currently on the market under conditions that approximate clinical use. The results using various Ascon lens-holding forceps and compression tests, during which the lenses were held in a cylindrical holder for seven days, one month, and three months, indicated that PVDF haptics had better shape recovery capability than PP and extruded three-piece PMMA haptics.

  2. Research of the long-focus Maksutov telephoto lens

    Science.gov (United States)

    Tarasov, I. P.; Tsyganok, E. A.

    2016-04-01

    The article presents the research result and the optical design of long-focus telephoto lens for photo shooting by the academician Maksutov's scheme. It shows a review of lenses for photo shooting on the market today, and also an analysis of the correctional possibilities which is based on the scheme is presented; studied long-focus telephoto lens is compared with its closest analog, the calculation of a new telephoto lens with higher image quality is made on the basis of that comparison.

  3. Characteristic of laser diode beam propagation through a collimating lens.

    Science.gov (United States)

    Xu, Qiang; Han, Yiping; Cui, Zhiwei

    2010-01-20

    A mathematical model of a laser diode beam propagating through a collimating lens is presented. Wave propagation beyond the paraxial approximation is studied. The phase delay of the laser diode wave in passing through the lens is analyzed in detail. The propagation optical field after the lens is obtained from the diffraction integral by the stationary phase method. The model is employed to predict the light intensity at various beam cross sections, and the computed intensity distributions are in a good agreement with the corresponding measurements.

  4. Development of a universal toric intraocular lens calculator

    Science.gov (United States)

    Hjelmstad, David; Sayegh, Samir I.

    2014-02-01

    We present a method for calculating the ideal toric lens to implant in astigmatic patients following cataract surgery. We show that the online calculators provided by major toric IOL manufacturers are insufficient for both theoretical and practical reasons. We reveal important theoretical shortcomings in their approach, illustrated by a number of cases which demonstrate how the approach can lead to errors in lens selection. Our approach combines the spherical and cylindrical power calculations into one, and allows for lens data from any manufacturer to be used, eliminating the reliance on multiple programs.

  5. Vortexlike Power Flow at the Interfaces of Metamaterial Lens

    Directory of Open Access Journals (Sweden)

    K. Fang

    2012-10-01

    Full Text Available The metamaterial lens with DPS/DNS/DPS structure has been realized by using the two-dimensional (2D isotropic transmission line approach. We studied the vortexlike power flow at the interfaces of metamaterial lens and validated by the finite-difference time-domain (FDTD simulator. The computational results showing its different conditions near DPS/DNS and other kinds of interfaces are obtained by CST STUDIO SUITE at different frequencies, and demonstrate the intuitionistic power location at the metamaterial lens interfaces.

  6. Means to flexibly attach lens frames to temple members

    Science.gov (United States)

    Smith, Harry D.

    1995-01-01

    The invention is a band hinge for flexibly connecting the temple member to the lens frame thereby preventing damage from inadvertent pressure or cyclic wear. A distinguishing feature of the invention is the use of a band hinge that holds together the temple member and the lens frame without the use of a pin or screw hinging mechanism. The invention allows for a high degree of freedom of movement for the temple member with respect to the lens frame which will prevent most forms of damages to the glasses from these types of events.

  7. 21 CFR 886.5918 - Rigid gas permeable contact lens care products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rigid gas permeable contact lens care products... contact lens care products. (a) Identification. A rigid gas permeable contact lens care product is a... rigid gas permeable contact lens. This includes all solutions and tablets used together with rigid...

  8. The Clearing : Heidegger’s Lichtung and the big scrub

    Directory of Open Access Journals (Sweden)

    Garbutt, Rob

    2010-01-01

    Full Text Available Clearings make settlement possible. Whether on a small scale using an axe and other hand implements to make way for a dwelling and a garden, or on a large scale with a chain strung between two D9 bulldozers in preparation for a major agribusiness development, the process of clearing creates spaces for installing something new. This paper uses the idea of (the clearing, as practice, process, outcome and metaphor, to examine the installation of the locals in a settler society. Using Lismore on the far-north coast of New South Wales, Australia, as a case example, the particular work of clearing that is discussed here is a practice that enables a form of colonisation and settlement that distances itself from its history of migration. This is a history of settler locals who were 'always here', and a colonial form of clearing clears the land and the mind of troubling pasts and of troubling presences. For the locals within a place, then, clearing manages and simplifies a complex set of social and material relations, histories and identities.Using Anthony Appiah's concept the 'space clearing gesture', the paper concludes with a reflection on the space in which the idea of "the clearing" and this paper appears. Do places, in this instance rural places, provide a type of clearing in which certain ideas might appear that may not appear elsewhere? If situatedness matters then the diversity of places where thinking is done is important for our ecology of thought, and in connection with this, perhaps what 'rural cultural studies' does is clear a particular type of space for thinking.

  9. The Clearing: Heidegger’s Lichtung and The Big Scrub

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2010-02-01

    Full Text Available Clearings make settlement possible. Whether on a small scale using an axe and other hand implements to make way for a dwelling and a garden, or on a large scale with a chain strung between two D9 bulldozers in preparation for a major agribusiness development, the process of clearing creates spaces for installing something new. This paper uses the idea of (the clearing, as practice, process, outcome and metaphor, to examine the installation of the locals in a settler society. Using Lismore on the far-north coast of New South Wales, Australia, as a case example, the particular work of clearing that is discussed here is a practice that enables a form of colonisation and settlement that distances itself from its history of migration. This is a history of settler locals who were 'always here', and a colonial form of clearing clears the land and the mind of troubling pasts and of troubling presences. For the locals within a place, then, clearing manages and simplifies a complex set of social and material relations, histories and identities. Using Anthony Appiah's concept the 'space clearing gesture', the paper concludes with a reflection on the space in which the idea of "the clearing" and this paper appears. Do places, in this instance rural places, provide a type of clearing in which certain ideas might appear that may not appear elsewhere? If situatedness matters then the diversity of places where thinking is done is important for our ecology of thought, and in connection with this, perhaps what 'rural cultural studies' does is clear a particular type of space for thinking.

  10. Outcomes of Lensectomy in Hereditary Lens Subluxation

    Directory of Open Access Journals (Sweden)

    Mohammad-Hossein Dehghan

    2008-12-01

    Full Text Available

    PURPOSE: To evaluate the results of pars plana lensectomy in patients with hereditary lens subluxation. METHOD: Hospital records of patients with hereditary lens subluxation who had undergone pars plana lensectomy at Labbafinejad Medical Center, Tehran-Iran from 1996 to 2003 were reviewed. Patients with more than 6 months of follow up were included. Underlying disorders, best corrected visual acuity (BCVA before and after surgery, intraocular pressure (IOP, postoperative refraction and complications were evaluated. RESULTS: Overall, records of 87 eyes of 49 patients including 27 male and 22 female subjects were reviewed. Mean follow up duration was 20±18 months. Underlying disorders leading to lens subluxation included Marfan syndrome (79.5%, Weill-Marchesani syndrome (8.2%, simple ectopia lentis (8.2%, and homocystinuria (4.1%. The most common indication for surgery was non-correctable refractive error (92.1%. Mean BCVA was 1.13 LogMAR (20/250 preoperatively, which improved to 0.26 LogMAR (20/30-20/40 postoperatively (P < 0.001. BCVA better than 20/40 was achieved in 82.8% of cases after surgery. Angle-supported anterior chamber intraocular lens (ACIOL was implanted in

  11. Growth Inhibition, Induction of Apoptosis by Green Tea Constituent (-)-Epigallocatechin-3-gallate in Cultured Rabbit Lens Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Wenyong Huang; Shaozhen Li; Junwen Zeng; Yizhi Liu; Mingxing Wu; Ming Zhang

    2000-01-01

    Purpose: To evaluate effect of green tea extract (-)-Epigallocatechin-3-gallate (EGCG)in cultured rabbit lens epithelial cells in order to pave a new way to postcapsular opacity (PCO) prevention.Methods: Cell survival rate was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) coloimetric assay. Cell apoptosis was detected by electron microscopy, Hochest 33258 stain and flow cytometer. DNA fragment was detected using agarose gel electrophoresis.Result: Proliferation of the cultured rabbit lens epithelia cells was inhibited by EGCG in a dose and time dependent manner. Morphologic study showed that the cells became shrunk, round shaped with their nuclei condensed and broken. Apoptotic bodies were also seen under electron microscope and in Hochest 33258 stain assay 24 hours after EGCG was added to the medium. DNA ladders were shown in agarose gel eletrophoresis.In flow cytometry assay, apoptosis peak was also evident.Conclusion: Green Tea Constituent(-)-Epigallocatechin-3-gallate could inhibit cultured rabbit lens epithelial cells proliferation by inducing their apoptosis in the concentration used by us, which indicates that it is possible to prevent PCO by using herb extract.

  12. SHARP - III. First use of adaptive-optics imaging to constrain cosmology with gravitational lens time delays

    Science.gov (United States)

    Chen, Geoff C.-F.; Suyu, Sherry H.; Wong, Kenneth C.; Fassnacht, Christopher D.; Chiueh, Tzihong; Halkola, Aleksi; Hu, I. Shing; Auger, Matthew W.; Koopmans, Léon V. E.; Lagattuta, David J.; McKean, John P.; Vegetti, Simona

    2016-11-01

    Accurate and precise measurements of the Hubble constant are critical for testing our current standard cosmological model and revealing possibly new physics. With Hubble Space Telescope (HST) imaging, each strong gravitational lens system with measured time delays can allow one to determine the Hubble constant with an uncertainty of ˜7 per cent. Since HST will not last forever, we explore adaptive-optics (AO) imaging as an alternative that can provide higher angular resolution than HST imaging but has a less stable point spread function (PSF) due to atmospheric distortion. To make AO imaging useful for time-delay-lens cosmography, we develop a method to extract the unknown PSF directly from the imaging of strongly lensed quasars. In a blind test with two mock data sets created with different PSFs, we are able to recover the important cosmological parameters (time-delay distance, external shear, lens-mass profile slope, and total Einstein radius). Our analysis of the Keck AO image of the strong lens system RXJ 1131-1231 shows that the important parameters for cosmography agree with those based on HST imaging and modelling within 1σ uncertainties. Most importantly, the constraint on the model time-delay distance by using AO imaging with 0.09 arcsec resolution is tighter by ˜50 per cent than the constraint of time-delay distance by using HST imaging with 0.09 arcsec when a power-law mass distribution for the lens system is adopted. Our PSF reconstruction technique is generic and applicable to data sets that have multiple nearby point sources, enabling scientific studies that require high-precision models of the PSF.

  13. Patient comfort following thirty minutes of lens wear: piggy-back versus conventional rigid-lens wear

    OpenAIRE

    W.D.H. Gillan

    2014-01-01

    Discomfort when wearing contact lenses, especially rigid contact lenses, is a common complaint amongst neophyte as well as experienced contact lens wearers. Wearing a piggy-back system of contact lenses has been shown to improve comfort and wearing time, especially in keratoconic subjects. Twenty two normal subjects wore a rigid lens or a piggy-back system of lenses for thirty minutes and after a thirty minute break swopped the mode of lens wear and wore the second modality for a thirty minut...

  14. Behind the money market: clearing and settling money market instruments

    OpenAIRE

    David L. Mengle

    1992-01-01

    When a money market instrument is traded, the clearing and settlement process establishes the change in ownership. Because the process involves both costs and risks, money market participants have developed means of making clearing and settlement more efficient and less risky.

  15. Glycogen-rich clear cell carcinoma of the breast

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Paulsen, S M

    1987-01-01

    The light microscopic, immunohistochemical and ultrastructural features of a clear cell carcinoma of the breast have been studied. Both intraductal and invasive components were found. Histochemistry showed large amounts of intracytoplasmic glycogen and sparse neutral mucin in the tumour. The tumour...... was classified as a mucin-containing variant of glycogen-rich, clear cell carcinoma of the breast....

  16. 75 FR 63113 - Financial Resources Requirements for Derivatives Clearing Organizations

    Science.gov (United States)

    2010-10-14

    ... customers or themselves, and non-FCMs that clear solely on behalf of themselves. See also the definition of... member may have a specific incentive to pay an assessment depending on the size and profitability of its... purposes of this calculation, if a clearing member had pays in both its house and customer accounts,...

  17. The Effectiveness of Clear Speech as a Masker

    Science.gov (United States)

    Calandruccio, Lauren; Van Engen, Kristin; Dhar, Sumitrajit; Bradlow, Ann R.

    2010-01-01

    Purpose: It is established that speaking clearly is an effective means of enhancing intelligibility. Because any signal-processing scheme modeled after known acoustic-phonetic features of clear speech will likely affect both target and competing speech, it is important to understand how speech recognition is affected when a competing speech signal…

  18. A New Type of distributed Enamel based Clearing Electrode

    CERN Document Server

    Kroyer, T; Caspers, Friedhelm; Hellmond, P; Métral, E; Wendel, J C; Zimmermann, F

    2007-01-01

    Clearing electrodes can be used for electron cloud (EC) suppression in high intensity particle accelerators. In this paper the use of low and highly resistive layers on a dielectric substrate are examined. The beam coupling impedance of such a structure is evaluated. Furthermore the clearing efficiency as well as technological issues are discussed.

  19. 76 FR 14471 - Clearing Agency Standards for Operation and Governance

    Science.gov (United States)

    2011-03-16

    ... Operation and Governance; Proposed Rule #0;#0;Federal Register / Vol. 76, No. 51 / Wednesday, March 16, 2011... Standards for Operation and Governance AGENCY: Securities and Exchange Commission. ACTION: Proposed rule... clearing agencies and standards for the operation and governance of clearing agencies. The proposed...

  20. ClearPEM: prototype PET device dedicated to breast imaging

    CERN Multimedia

    Joao Varela

    2009-01-01

    Clinical trials have begun in Portugal on a new breast imaging system (ClearPEM) using positron emission tomography (PET). The system, developed by a Portuguese consortium in collaboration with CERN and laboratories participating in the Crystal Clear collaboration, will detect even the smallest tumours and thus help avoid unnecessary biopsies.

  1. 18 CFR 367.1840 - Account 184, Clearing accounts.

    Science.gov (United States)

    2010-04-01

    ... ACT Balance Sheet Chart of Accounts Deferred Debits § 367.1840 Account 184, Clearing accounts. This account must include undistributed balances in clearing accounts at the date of the balance sheet... accounts. 367.1840 Section 367.1840 Conservation of Power and Water Resources FEDERAL ENERGY...

  2. Intraocular lens exchange for high myopia in pseudophakic children.

    Science.gov (United States)

    Kraus, C L; Trivedi, R H; Wilson, M E

    2016-09-01

    PurposeThe purpose of this study was to examine the preoperative factors and postoperative outcomes following intraocular lens (IOL) exchange for high myopia in pseudophakic children.MethodsThe medical records of all patients undergoing IOL exchange for high myopia were retrospectively reviewed.ResultsA total of 15 eyes were identified that had undergone an IOL exchange for myopic shift. Average age of cataract extraction (CE) was 5.4 months. In all, 10/15 had a unilateral cataract. IOL exchange usually occurred at an average of 6 years following cataract surgery. The average spherical equivalent (SE) of the refractive error at that time was -9.6 D. Following IOL exchange, SE was -1.3 D. A two-line reduction in best-corrected visual acuity was observed in 1/13 of our patients for whom pre- and post-exchange data were available. The average axial length (AL) of the eye undergoing the IOL exchange was 24.0 mm, average AL in the non-operative eye was 22.1 mm. On average, the operative eyes grew 4.4 mm and the non-operative eyes 3.02 mm. No adverse events were seen in the operative eyes.ConclusionYounger age at the time of CE creates a greater likelihood of AL elongation and predisposes a child to myopic shift. IOL exchange should be considered an option to reduce anisometropia and associated aniseikonia to improve visual outcomes. Successful visual rehabilitation and predictable post-exchange refractions were seen with our patients.

  3. A simple formula for determining globally clear skies

    Energy Technology Data Exchange (ETDEWEB)

    Long, C.N.; George, A.T.; Mace, G.G. [Penn State Univ., University Park, PA (United States)] [and others

    1996-04-01

    Surface measurements to serve as {open_quotes}ground truth{close_quotes} are of primary importance in the development of retrieval algorithms using satellite measurements to predict surface irradiance. The most basic algorithms of this type deal with clear sky (i.e., cloudless) top-to-surface shortwave (SW) transfer, serving as a necessary prerequisite towards treating both clear and cloudy conditions. Recently, atmosphere SW cloud forcing to infer the possibility of excess atmospheric absorption (compared with model results) in cloudy atmospheres. The surface component of this ratio relies on inferring the expected clear sky SW irradiance to determine the effects of clouds on the SW energy budget. Solar renewable energy applications make use of clear and cloud fraction climatologies to assess solar radiation resources. All of the above depend to some extent on the identification of globally clear sky conditions and the attendant measurements of downwelling SW irradiance.

  4. Degeneracies of parametric lens model families near folds and cusps

    CERN Document Server

    Wagner, Jenny

    2015-01-01

    We develop an approach to select families of lens models that can describe doubly and triply gravitationally lensed images near folds and cusps using the model-independent ratios of lensing-potential derivatives derived in Wagner & Bartelmann (2015). Models are selected by comparing these model-independent ratios of potential derivatives to (numerically determined) ratios of potential derivatives along critical curves for entire lens model families in a given range of parameter values. This comparison returns parameter ranges which lens model families can reproduce observation within, as well as sections of the critical curve where image sets of the observed type can appear. If the model-independent potential-derivative ratios inferred from the observation fall outside the range of these ratios derived for the lens model family, the entire family can be excluded as a feasible model in the given volume in parameter space. We employ this approach for the family of singular isothermal spheres with external s...

  5. Applications of thermal lens spectrometry in food industry and agriculture.

    NARCIS (Netherlands)

    Franko, M.; Bicanic, D.; Gibkes, J.; Bremer, M.; Akkermans, E.

    1996-01-01

    Applications of CO laser dual beam thermal lens spectrometry (TLS) for detection and characterization of fatty acids, aldehydes, pesticides, and herbicides in liquid samples are described. Also reported is the first TLS measurement of thermal conductivity for oleic acid.

  6. Constraints on cosmological models from lens redshift data

    CERN Document Server

    Cao, Shuo

    2011-01-01

    Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structures, formations, and evolutions). Now several hundreds of strong lens systems produced by massive galaxies have been discovered, which may form well-defined samples useful for statistical analyses. To collect a relatively complete lens redshift data from various large systematic surveys of gravitationally lensed quasars and check the possibility to use it as a future complementarity to other cosmological probes. We use the distribution of gravitationally-lensed image separations observed in the Cosmic Lens All-Sky Survey (CLASS), the PMN-NVSS Extragalactic Lens Survey (PANELS), the Sloan Digital Sky Survey (SDSS) and other surveys, considering a singular isothermal ellipsoid (SIE) model for galactic potentials as well as improved new measurements of the velocity dispersion function of galaxies based on the SDSS DR5 data and recent semi-analytical modeling of galaxy formation, to constrain tw...

  7. Multiaxial mechanical behavior of the porcine anterior lens capsule.

    Science.gov (United States)

    Heistand, M R; Pedrigi, R M; Delange, S L; Dziezyc, J; Humphrey, J D

    2005-11-01

    The biomechanics of the lens capsule of the eye is important both in physiologic processes such as accommodation and clinical treatments such as cataract surgery. Although the lens capsule experiences multiaxial stresses in vivo, there have been no measurements of its multiaxial properties or possible regional heterogeneities. Rather all prior mechanical data have come from 1-D pressure-volume or uniaxial force-length tests. Here, we report a new experimental approach to study in situ the regional, multiaxial mechanical behavior of the lens capsule. Moreover, we report multiaxial data suggesting that the porcine anterior lens capsule exhibits a typical nonlinear pseudo-elastic behavior over finite strains, that the in situ state is pre-stressed multi-axially, and that the meridional and circumferential directions are principal directions of strain, which is nearly equi-biaxial at the pole but less so towards the equator. Such data are fundamental to much needed constitutive formulations.

  8. Regional multiaxial mechanical properties of the porcine anterior lens capsule.

    Science.gov (United States)

    David, G; Pedrigi, R M; Heistand, M R; Humphrey, J D

    2007-02-01

    The lens capsule of the eye plays fundamental biomechanical roles in both normal physiological processes and clinical interventions. There has been modest attention given to the mechanical properties of this important membrane, however, and prior studies have focused on 1-D analyses of the data. We present results that suggest that the porcine anterior lens capsule has a complex, regionally dependent, nonlinear, anisotropic behavior. Specifically, using a subdomain inverse finite element method to analyze data collected via a new biplane video-based test system, we found that the lens capsule is nearly isotropic (in-plane) near the pole but progressively stiffer in the circumferential compared to the meridional direction as one approaches the equator. Because the porcine capsule is a good model of the young human capsule, there is strong motivation to determine if similar regional variations exist in the human lens capsule for knowledge of such complexities may allow us to improve the design of surgical procedures and implants.

  9. 600 Volt Stretched Lens Array for Solar Electric Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past six years, ENTECH, Auburn, NASA, and other organizations have developed a new space photovoltaic array called the Stretched Lens Array (SLA), which...

  10. An Atomic Lens Using a Focusing Hollow Beam

    Institute of Scientific and Technical Information of China (English)

    夏勇; 印建平; 王育竹

    2003-01-01

    We propose a new method to generate a focused hollow laser beam by using an azimuthally distributed 2π-phase plate and a convergent thin lens, and calculate the intensity distribution of the focused hollow beam in free propagation space. The relationship between the waist w0 of the incident collimated Gaussian beam and the dark spot size of the focused hollow beam at the focal point, and the relationship between the focal length f of the thin lens and the dark spot size are studied respectively. The optical potential of the blue-detuned focused hollow beam for 85Rb atoms is calculated. Our study shows that when the larger waist w of the incident Gaussian beam and the shorter focal length f of the lens are chosen, we can obtain an extremely small dark spot size of the focused hollow beam, which can be used to form an atomic lens with a resolution of several angstroms.

  11. Application of Foldable Intraocular Lens in Multiple Types of Cataract

    Institute of Scientific and Technical Information of China (English)

    Songtao Yuan; Qinghuai Liu; Qing Jiang; Nanrong Yuan

    2002-01-01

    Objective: To evaluate the clinical results of implantation of foldable intraocular lens inmultiple types of cataract.Methods: This retrospective study comprised 162 eyes of 148 patients undergoingphacoemulsification and implantation of foldable intraocular lens, some of whom under-went combined pars plana vitrectomy or trabeculectomy or silicone oil removal. Theperiod of follow-up was from 3 months to 17 months.Results: There is slight reaction postoperatively in all cases. The postoperative uncorrectedvisual acuites was from 0. 05 to 1.2, patient with 0.6 or above acuity were 70.98%. Aneodymium: YAG capsulotomy was required in 5 eyes. Posterior capsule ruptured in 1eyes, and a PMMA intraocular lens was implanted in ciliary sulcus. In one eye, a lenswas removed because of recurrence of retina detachment.Conclusions: The application of foldable intraocular lens in multiple types of cataract issafe, and there is a slight postoperative reaction. less complications , and fast visualacuity recovery.

  12. Ultra-precision molding of chalcogenide glass aspherical lens

    Science.gov (United States)

    Zhang, Feng; Wang, Zhibin; Zhang, Yunlong; Su, Ying; Guo, Rui; Xu, Zengqi; Liu, Xuanmin

    2016-10-01

    With the development of infrared optical systems in military and civil areas, chalcogenide glass aspherical lens possess some advantages, such as large infrared transmission, good thermal stability performance and image quality. Aspherical lens using chalcogenide glass can satisfy the requirements of modern infrared optical systems. Therefore, precision manufacturing of chalcogenide glass aspheric has received more and more attention. The molding technology of chalcogenide glass aspheric has become a research hotspot, because it can achieve mass and low cost manufacturing. The article of molding technology is focusing on a kind of chalcogenide glass aspherical lens. We report on design and fabrication of the mold that through simulation analysis of molding. Finally, through molding test, the fabrication of mold's surface and parameters of molding has been optimized, ensuring the indicators of chalcogenide glass aspherical lens meet the requirements.

  13. Tunable Focus Liquid Lens with Radial-Patterned Electrode

    Directory of Open Access Journals (Sweden)

    Miao Xu

    2015-08-01

    Full Text Available A dielectric liquid lens is prepared based on our previous work. By optimizing the device structure, the liquid lens presents a converging focus with good resolution and changes its focal length over a broad range with a low driving voltage. For a liquid lens with ~2.3 mm diameter in the relaxed state, it can resolve ~40 lp/mm. The resolution does not degrade during focus change. Its focal length can be varied from ~12 to ~5 mm when the applied voltage is changed from 0 to 28 Vrms. The response time of one cycle is ~2.5 s. Our liquid lens, with a low driving voltage for a large dynamic range, has potential applications in imaging, biometrics, optoelectronic, and lab-on-chip devices.

  14. A spiral plasmonic lens with directional excitation of surface plasmons.

    Science.gov (United States)

    Guo, Qingrui; Zhang, Chi; Hu, Xinhua

    2016-08-26

    Conventional plasmonic lenses are composed of curved slits carved through metallic films. Here, we propose a new plasmonic lens based on a metallic slit with an auxiliary groove. When the lens is illumined normally, only inward surface plasmon polaritons (SPPs) can be generated and then focused into a hot spot at the center of the lens. The focusing effect is theoretically investigated by varying the groove parameters and incident polarizations. It is found that this phenomenon exists for both the circular and linear polarizations of incidence. Under optimal groove parameters, the intensity of the focal spot in our lens can be 2.5 times of that in one without grooves for both linearly and circularly polarized illuminations.

  15. A single-pixel wireless contact lens display

    Science.gov (United States)

    Lingley, A. R.; Ali, M.; Liao, Y.; Mirjalili, R.; Klonner, M.; Sopanen, M.; Suihkonen, S.; Shen, T.; Otis, B. P.; Lipsanen, H.; Parviz, B. A.

    2011-12-01

    We present the design, construction and in vivo rabbit testing of a wirelessly powered contact lens display. The display consists of an antenna, a 500 × 500 µm2 silicon power harvesting and radio integrated circuit, metal interconnects, insulation layers and a 750 × 750 µm2 transparent sapphire chip containing a custom-designed micro-light emitting diode with peak emission at 475 nm, all integrated onto a contact lens. The display can be powered wirelessly from ~1 m in free space and ~2 cm in vivo on a rabbit. The display was tested on live, anesthetized rabbits with no observed adverse effect. In order to extend display capabilities, design and fabrication of micro-Fresnel lenses on a contact lens are presented to move toward a multipixel display that can be worn in the form of a contact lens. Contact lenses with integrated micro-Fresnel lenses were also tested on live rabbits and showed no adverse effect.

  16. Negative time delay of light by a gravitational concave lens

    CERN Document Server

    Nakajima, Koki; Asada, Hideki

    2014-01-01

    Gravitational lens models, some of which might act as if a concave lens, have been recently investigated by using a static and spherically symmetric modified spacetime metric that depends on the inverse distance to the $n$-th power [Kitamura, Nakajima and Asada, PRD 87, 027501 (2013)]. We reexamine the time delay of light in a gravitational concave lens as well as a gravitational convex one. The frequency shift due to the time delay is also investigated. We show that the sign of the time delay in the lens models is the same as that of the deflection angle of light. The size of the time delay decreases with increase in the parameter $n$. We discuss also possible parameter ranges that are relevant to pulsar timing measurements in our galaxy.

  17. A 3D printed helical antenna with integrated lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2015-10-26

    A novel antenna configuration comprising a helical antenna with an integrated lens is demonstrated in this work. The antenna is manufactured by a unique combination of 3D printing of plastic material (ABS) and inkjet printing of silver nano-particle based metallic ink. The integration of lens enhances the gain by around 7 dB giving a peak gain of about 16.4 dBi at 9.4 GHz. The helical antenna operates in the end-fire mode and radiates a left-hand circularly polarized (LHCP) pattern. The 3-dB axial ratio (AR) bandwidth of the antenna with lens is 3.2 %. Due to integration of lens and fully printed processing, this antenna configuration offers high gain performance and requires low cost for manufacturing.

  18. Perforation forces of the intact porcine anterior lens capsule.

    Science.gov (United States)

    Ullrich, Franziska; Lussi, Jonas; Felekis, Dimitrios; Michels, Stephan; Petruska, Andrew J; Nelson, Bradley J

    2016-09-01

    During the first step of cataract surgery, the lens capsule is perforated and a circular hole is created with a sharp instrument, a procedure called capsulorhexis. To develop automated systems that can assist ophthalmologists during capsulorhexis, the forces required must be quantified. This study investigates perforation forces of the central anterior lens capsule in porcine eyes, which are used as a conservative model for the human eye. A micro-mechanical characterisation method is presented that measures capsular bag perforation forces with a high precision positioning and high-resolution force sensing system. The force during perforation of the anterior lens capsule was measured with various sized needles and indentation speeds and is found to be 15-35mN. A bio-mechanical model is identified that describes an exponential correlation between indentation force and depth, indicating strain hardening behaviour of the porcine anterior lens capsule.

  19. Fibroblast growth factor receptor signaling is essential for lens fiber cell differentiation

    OpenAIRE

    Zhao, Haotian; Yang, Tianyu; Madakashira, Bhavani P.; Thiels, Cornelius A.; Bechtle, Chad A.; Garcia, Claudia M.; Zhang, Huiming; Yu, Kai; Ornitz, David M.; Beebe, David C.; Robinson, Michael L.

    2008-01-01

    The vertebrate lens provides an excellent model to study the mechanisms that regulate terminal differentiation. Although fibroblast growth factors (FGFs) are thought to be important for lens cell differentiation, it is unclear which FGF receptors mediate these processes during different stages of lens development. Deletion of three FGF receptors (Fgfr1-3) early in lens development demonstrated that expression of only a single allele of Fgfr2 or Fgfr3 was sufficient for grossly normal lens dev...

  20. Softec HD hydrophilic acrylic intraocular lens: biocompatibility and precision

    OpenAIRE

    Ladan Espandar; Shameema Sikder; Majid Moshirfar

    2011-01-01

    Ladan Espandar1, Shameema Sikder2, Majid Moshirfar31Department of Ophthalmology, Tulane University, New Orleans, LA, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 3John A Moran Eye Center, University of Utah, Salt Lake City, UT, USAAbstract: Intraocular lens development is driven by higher patient expectations for ideal visual outcomes. The recently US Food and Drug Administration-approved Softec HD™ lens is an aspheric, hydrophilic acrylic intraocular le...

  1. Patient acceptability of the Tecnis® multifocal intraocular lens

    OpenAIRE

    Woodward, Maria; Sood,Priyanka

    2011-01-01

    Priyanka Sood1, Maria A Woodward21Emory Eye Center, Atlanta, GA, USA; 2Kellogg Eye Center, Ann Arbor, MI, USAAbstract: Cataract surgery has evolved. The goal of the surgeon includes both restoration of vision and refinement of vision. Patients' desire for spectacle independence has driven the market for presbyopia-correcting cataract surgery and development of novel intraocular lens (IOL) designs. The Tecnis® Multifocal Intraocular Lens incorporates an aspheric, modified anter...

  2. Supersymmetric black holes with lens-space topology.

    Science.gov (United States)

    Kunduri, Hari K; Lucietti, James

    2014-11-21

    We present a new supersymmetric, asymptotically flat, black hole solution to five-dimensional supergravity. It is regular on and outside an event horizon of lens-space topology L(2,1). It is the first example of an asymptotically flat black hole with lens-space topology. The solution is characterized by a charge, two angular momenta, and a magnetic flux through a noncontractible disk region ending on the horizon, with one constraint relating these.

  3. Signal-enhancement reflective pulse oximeter with Fresnel lens

    Science.gov (United States)

    Chung, Shuang-Chao; Sun, Ching-Cherng

    2016-09-01

    In this paper, a new reflective pulse oximeter is proposed and demonstrated with implanting a Fresnel lens, which enhances the reflected signal. An optical simulation model incorporated with human skin characteristics is presented to evaluate the capability of the Fresnel lens. In addition, the distance between the light emitting diode and the photodiode is optimized. Compared with the other reflective oximeters, the reflected signal light detected by the photodiode is enhanced to more than 140%.

  4. Design and simulation of large field plate lithography lens

    Science.gov (United States)

    Deng, Chao; Xing, Tingwen; Lin, Wumei; Zhu, Xianchang

    2016-10-01

    Because industry demand for LED,LCD panel continues to increase, the high yield of micron-scale resolution lithography is increasingly prominent for manufacturers, which requires the field of lithography objective lens becomes larger. This paper designed a lithography lens with large field, whose effective image side field will reach to 132 × 132mm.Subsequently, the tolerance was analysed by simulation for the optical system. Finally, it is proved that the design meets the requirements of micron-scale resolution.

  5. OPTICAL REALIZATION OF WAVELET TRANSFORM WITH A SINGLE LENS

    Institute of Scientific and Technical Information of China (English)

    王取泉; 熊贵光; 李承芳; 张苏淮; 王琳

    2001-01-01

    Two optical set-ups to implement wavelet transform with a single lens have been proposed, in which the wavelet filter was placed in front of the imaging lens or on the frequency plane. The general formula of the complex field distribution of the output plane has been deduced. The analysing wavelet functions of the band-pass wavelet filters with double and circular slits have been discussed.

  6. Adjusting to a sudden “aging” of the lens

    OpenAIRE

    Tregillus, KEM; Werner., JS; Webster, MA

    2016-01-01

    Color perception is known to remain largely stable across the lifespan despite the pronounced changes in sensitivity from factors such as the progressive brunescence of the lens. However, the mechanisms and timescales controlling these compensatory adjustments are still poorly understood. In a series of experiments, we tracked adaptation in observers after introducing a sudden change in lens density by having observers wear glasses with yellow filters that approximated the average spectral tr...

  7. Adaptive neuro-fuzzy estimation of optimal lens system parameters

    Science.gov (United States)

    Petković, Dalibor; Pavlović, Nenad T.; Shamshirband, Shahaboddin; Mat Kiah, Miss Laiha; Badrul Anuar, Nor; Idna Idris, Mohd Yamani

    2014-04-01

    Due to the popularization of digital technology, the demand for high-quality digital products has become critical. The quantitative assessment of image quality is an important consideration in any type of imaging system. Therefore, developing a design that combines the requirements of good image quality is desirable. Lens system design represents a crucial factor for good image quality. Optimization procedure is the main part of the lens system design methodology. Lens system optimization is a complex non-linear optimization task, often with intricate physical constraints, for which there is no analytical solutions. Therefore lens system design provides ideal problems for intelligent optimization algorithms. There are many tools which can be used to measure optical performance. One very useful tool is the spot diagram. The spot diagram gives an indication of the image of a point object. In this paper, one optimization criterion for lens system, the spot size radius, is considered. This paper presents new lens optimization methods based on adaptive neuro-fuzzy inference strategy (ANFIS). This intelligent estimator is implemented using Matlab/Simulink and the performances are investigated.

  8. Lens Systems for Sky Surveys and Space Surveillance

    Science.gov (United States)

    Ackermann, M.; McGraw, J.; Zimmer, P.

    2013-09-01

    Since the early days of astrophotography, lens systems have played a key role in capturing images of the night sky. The first images were attempted with visual-refractors. These were soon followed with color-corrected refractors and finally specially designed photo-refractors. Being telescopes, these instruments were of long-focus and imaged narrow fields of view. Simple photographic lenses were soon put into service to capture wide-field images. These lenses also had the advantage of requiring shorter exposure times than possible using large refractors. Eventually, lenses were specifically designed for astrophotography. With the introduction of the Schmidt-camera and related catadioptric systems, the popularity of astrograph lenses declined, but surprisingly, a few remained in use. Over the last 30 years, as small CCDs have displaced large photographic plates, lens systems have again found favor for their ability to image great swaths of sky in a relatively small and simple package. In this paper, we follow the development of lens-based astrograph systems from their beginnings through the current use of both commercial and custom lens systems for sky surveys and space surveillance. Some of the optical milestones discussed include the early Petzval-type portrait lenses, the Ross astrographic lens and the current generation of optics such as the commercial 200mm camera lens by Canon, and the Russian VT-53e in service with ISON.

  9. Design of wide field and high resolution video lens

    Science.gov (United States)

    Xiao, Ze-xin; Zhan, Binzhou; Han, Haimei

    2009-11-01

    Online detecting is increasingly used in industrial process for the requirement of product quality improving. It is a trend that the "machine detecting" with "machine version + computer intelligence" as new method replaces traditional manual "eye observation". The essential of "machine detecting" is that image of object being collected with high resolution video lens on sensor panel of photoelectric (CCD ,CMOS) and detecting result being automatically gained by computer after the image saved and processed. "Machine detecting" is developing rapidly with the universal reception by enterprises because of its fine accurateness, high efficiency and the real time. Video lens is one of the important components of machine version system. Requirements of wide field and high resolution enlarged the complexity of video lens design. In this paper a design case used in visible light with field diameter Φ32mm, β=-0.25× and NA'=0.15. We give design parameters of the video lens which obtained with theoretically calculating and Oslo software optimization: MTF>0.3 in full field and 215lp/mm, distortion <0.05%.This lens has an excellent optic performance to match with 1.3 million pixels 1/2"CCD, and a high performance price ratio for being consist of only 7 single lens in the way of 5 units.

  10. The Embedded Transparent Lens and Fermat's Least-Time Principle

    CERN Document Server

    Kantowski, Ronald; Dai, Xinyu

    2013-01-01

    We present a much simplified version of the embedded point mass lens theory and then make the obvious extension of this theory to any embedded transparent lens. Embedding a lens effectively reduces the gravitational potential's range, i.e., partially shields the lensing potential because the lens mass is made a contributor to the mean mass density of the universe and not simply superimposed upon it. This presentation results from simplifying previous formulations of the embedded point mass theory and is quite similar to the standard theory. We are then able to re-derive the simplified point mass theory by applying Fermat's least-time principle to the time-delay function. Even though rigorous derivations are only made for the point mass, the lens equation to the lowest order for any distributed lens, is obvious. We find from this simplified theory that embedding can introduce corrections at the few percent level in weak lensing shears caused by large clusters but only at large impacts. The potential part of th...

  11. Bio-inspired fluidic lens surgical camera for MIS.

    Science.gov (United States)

    Tsai, Frank S; Johnson, Daniel; Cho, Sung Hwan; Qiao, Wen; Arianpour, Ashkan; Lo, Yu-Hwa

    2009-01-01

    We report a new type of surgical camera that will greatly improve minimally invasive surgery (MIS). The key enabling technology for this camera is a unique type of lens-bio-inspired fluidic lens, which is a bio-mimetic lens that can change its curvature, just like the way human crystalline lens can accommodate. Because of its curvature changing capability, it is now possible to design a new regime of optical systems where auto-focusing and optical zoom can be performed without moving the lens positions, as is done in typical cameras. Hence, miniaturized imaging system with high functionality can be achieved with such technology. MIS is a surgical technique where small incisions are made on the abdominal wall as opposed to a large cut in open surgery. This type of surgery ensures faster patient recovery. The key tool for MIS is its surgical camera, or laparoscope. Traditional laparoscope is long and rigid and limits the field of view. To further advance MIS technology, we utilized bio-inspired fluidic lens to design a highly versatile imager that is small, can change its field of view or zoom optically, works in low light conditions, and varies the viewing angles. The surgical camera prototype is small (total track<17 mm), possesses 3X optical zoom, operates with light emitting diode (LED) lighting, among many other unique features.

  12. Flat Lens Focusing Demonstrated With Left-Handed Metamaterial

    Science.gov (United States)

    Wilson, Jeffrey D.; Schwartz, Zachary D.; Chevalier, Christine T.; Downey, Alan N.; Vaden, Karl R.

    2004-01-01

    Left-handed metamaterials (LHM's) are a new media engineered to possess an effective negative index of refraction over a selected frequency range. This characteristic enables LHM's to exhibit physical properties never before observed. In particular, a negative index of refraction should cause electromagnetic radiation to refract or bend at a negative angle when entering an LHM, as shown in the figure above on the left. The figure on the right shows that this property could be used to bring radiation to a focus with a flat LHM lens. The advantage of a flat lens in comparison to a conventional curved lens is that the focal length could be varied simply by adjusting the distance between the lens and the electromagnetic wave source. In this in-house work, researchers at the NASA Glenn Research Center developed a computational model for LHM's with the three-dimensional electromagnetic commercial code Microwave Studio, constructed an LHM flat lens, and used it to experimentally demonstrate the reversed refraction and flat lens focusing of microwave radiation.

  13. Bloqueio extraconal para facectomia com implante de lente intra-ocular: influência da via de acesso (superior ou inferior na qualidade da anestesia Bloqueo extraconal para facectomia con implantación de lente intra-ocular: influencia de la vía de acceso (superior o inferior en la calidad de la anestesia Extraconal block for cataract extraction surgery with implantation of intraocular lens: influence of access way (upper or lower in anesthetic outcome

    Directory of Open Access Journals (Sweden)

    Daniel Espada Lahoz

    2003-08-01

    bloqueo locorregional para cirugía de facectomia con implantación de lente intra-ocular.BACKGROUND AND OBJECTIVES: There is no completely safe anesthetic technique for ophthalmic surgery. The introduction of extraconal anesthesia has increased the number of ophthalmic surgeries with blockade since the incidence of severe complications is lower, as reported by Hay in 1991. Extraconal blockades may be induced by several access ways, among them upper and lower ways. This study aimed at evaluating the influence access ways (upper or lower in anesthetic outcome. METHODS: Participated in this study 164 patients of both genders, aged 23 to 92 years, physical status ASA I to IV, 1 and 2 Goldman’s cardiac risk index, undergoing elective cataract extraction surgery with intraocular lens implantation. Patients were randomly distributed in two groups of 82 according to primary extraconal block access way: group UE (upper extraconal, group LE (lower extraconal. Blockade quality was evaluated by the following parameters: intraoperative pain, eyelid and/or eyeball movement, persistence of Bell´s reflex, number of blocks needed for eye akinesia, and surgeon’s evaluation. RESULTS: Upper extraconal approach was associated to more effective eyelid (upper access - 56.1%; lower access 36.6% and superior rectus muscle akinesia (upper access - 93.9%; lower access 65.9% and also a lower incidence of supplementary blocks (upper access - 29.3%; lower access 42.7%. The lower extraconal approach was associated to more effective inferior rectus muscle akinesia (upper access - 72%; lower access - 84.1%, however without statistical differences. CONCLUSIONS: In the conditions of this study the upper extraconal approach was better as compared to the lower approach as the primary access way for anesthetic block for cataract extraction with intraocular lens implantation.

  14. Molecular basis for optical clearing of collagenous tissues

    Science.gov (United States)

    Hirshburg, Jason M.; Ravikumar, Krishnakumar M.; Hwang, Wonmuk; Yeh, Alvin T.

    2010-09-01

    Molecular interactions of optical clearing agents were investigated using a combination of molecular dynamics (MD) simulations and optical spectroscopy. For a series of sugar alcohols with low to high optical clearing potential, Raman spectroscopy and integrating sphere measurements were used to quantitatively characterize tissue water loss and reduction in light scattering following agent exposures. The rate of tissue water loss was found to correlate with agent optical clearing potential, but equivalent tissue optical clearing was measured in native and fixed tissue in vitro, given long-enough exposure times to the polyol series. MD simulations showed that the rate of tissue optical clearing correlated with the preferential formation of hydrogen bond bridges between agent and collagen. Hydrogen bond bridge formation disrupts the collagen hydration layer and facilitates replacement by a chemical agent to homogenize tissue refractive index. However, the reduction in tissue light scattering did not correlate with the agent index of refraction. Our results suggest that a necessary property of optical clearing agents is hyperosmolarity to tissue, but that the most effective agents with the highest rates of optical clearing are a subset with the highest collagen solubilities.

  15. Dark energy with gravitational lens time delays

    CERN Document Server

    Treu, T; Cyr-Racine, F -Y; Fassnacht, C D; Keeton, C R; Linder, E V; Moustakas, L A; Bradac, M; Buckley-Geer, E; Collett, T; Courbin, F; Dobler, G; Finley, D A; Hjorth, J; Kochanek, C S; Komatsu, E; Koopmans, L V E; Meylan, G; Natarajan, P; Oguri, M; Suyu, S H; Tewes, M; Wong, K C; Zabludoff, A I; Zaritsky, D; Anguita, T; Brunner, R J; Cabanac, R; Falco, E E; Fritz, A; Seidel, G; Howell, D A; Giocoli, C; Jackson, N; Lopez, S; Metcalf, R B; Motta, V; Verdugo, T

    2013-01-01

    Strong lensing gravitational time delays are a powerful and cost effective probe of dark energy. Recent studies have shown that a single lens can provide a distance measurement with 6-7 % accuracy (including random and systematic uncertainties), provided sufficient data are available to determine the time delay and reconstruct the gravitational potential of the deflector. Gravitational-time delays are a low redshift (z~0-2) probe and thus allow one to break degeneracies in the interpretation of data from higher-redshift probes like the cosmic microwave background in terms of the dark energy equation of state. Current studies are limited by the size of the sample of known lensed quasars, but this situation is about to change. Even in this decade, wide field imaging surveys are likely to discover thousands of lensed quasars, enabling the targeted study of ~100 of these systems and resulting in substantial gains in the dark energy figure of merit. In the next decade, a further order of magnitude improvement will...

  16. The correction of electron lens aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, P.W., E-mail: peter.hawkes@cemes.fr

    2015-09-15

    The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague. - Highlights: • Geometrical aberration correction. • Chromatic aberration correction. • 50 pm resolution. • High-resolution electron energy-loss spectroscopy. • Extensive bibliographies.

  17. Hemispherical projection lens for insect behavior analysis

    Science.gov (United States)

    Aikio, Mika; Takalo, Jouni; Lempeä, Mikko; Vähäsöyrinki, Mikko

    2010-05-01

    Virtual reality projection systems have been used formerly to study if mammals, including humans, are able to act in or understand virtual environments. Insects have been more difficult to study in such circumstances, one of the factors being their large, almost hemispherical field of view. Designing such a projection system that is capable of fulfilling the full field of vision of an insect is a challenging task. Normally, when designing a photographic objective, one of the goals is to minimize field curvature in order to provide sharp image through the whole sensor surface. However, because the image surface in this case is a sphere, flat field is not desirable and the design task becomes an opposite of a typical camera lens. Introducing field curvature becomes mandatory. We have designed and built a system with satisfactory image quality throughout the whole spherical surface with reasonable number of lenses as an add-on for common digital projectors. The manufactured system is able to project an image to a solid angle of 11.95 steradians, and when compared to the whole sphere which is represented with a solid angle of 4π steradians, approximately 5 % of the total sphere area is not illuminated.

  18. HIGH-CURRENT COLD CATHODE FIELD EMISSION ARRAY FOR ELECTRON LENS APPLICATION

    Energy Technology Data Exchange (ETDEWEB)

    Hirshfield, Jay L

    2012-12-28

    During Phase I, the following goals were achieved: (1) design and fabrication of a novel, nano-dimensional CNT field emitter assembly for high current density application, with high durability; (2) fabrication of a ceramic based micro channel plate (MCP) and characterization of its secondary electron emission; and (3) characterizing the CNT/MCP cathode for high field emission and durability. As a result of these achievements, a relatively high current density of ~ 1.2 A/cm2 from a CNT cathode and single channel MCP were measured. The emission current was also extremely stable with a peak-to-peak variation of only 1.8%. The emission current could be further enhanced to meet requirements for electron lens applications by increasing the number of MCP channels. A calculation for maximum possible current density with a 1200 channel/cm2 MCP, placed over a cathode with 1200 uniformly functioning CNTs, would be ~1.46 kA/cm2, neglecting space charge limitations. Clearly this level of emission is far greater than what is needed for the electron lens application, but it does offer a highly comforting margin to account for sub-standard emitters and/or to allow the lesser challenge of building a cathode with fewer channels/cm2. A satisfactory goal for the electron lens application would be a controllable emission of 2-4 mA per channel in an ensemble of 800-1200 uniformly-functioning channels/cm2, and a cathode with overall area of about 1 cm2.

  19. Tooth extraction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007630.htm Tooth extraction To use the sharing features on this page, please enable JavaScript. A tooth extraction is a procedure to remove a tooth from ...

  20. Clear cell sarcoma: A case mimicking primary cutaneous malignant melanoma

    Directory of Open Access Journals (Sweden)

    Rodriguez-Martin M

    2009-01-01

    Full Text Available Clear cell sarcoma (CCS is a recently described variant of sarcoma characterized by prominent clear cells showing features similar to clear cell melanoma. This neoplasm was first described by Dr. Franz M. Erzinger. Primary CCS usually arises in deeper soft tissues, in association with fascia, tendons, or aponeuroses. Characteristic translocation t(12;22 (q13;q12 has been considered pathognomonic for CCS. Prognosis is related to tumor size. An early recognition and initial radical surgery is the key to a favourable outcome. We present a patient with an unusual neoplasm that resembled malignant melanoma.

  1. Clear-PEM, a dedicated PET camera for mammography

    CERN Document Server

    Lecoq, P

    2002-01-01

    Preliminary results suggest that Positron Emission Mammography (PEM) can offer a noninvasive method for the diagnosis of breast cancer. Metabolic images from PEM contain unique information not available from conventional morphologic imaging techniques and aid in expeditiously establishing the diagnosis of cancer. A dedicated machine seems to offer better perspectives in terms of position resolution and sensitivity. This paper describes the concept of Clear-PEM, the system presently developed by the Crystal Clear Collaboration at CERN for an evaluation of this approach. This device is based on new crystals introduced by the Crystal Clear as well as on modern data acquisition techniques developed for the large experiments in high energy physics experiments.

  2. Development of an accommodating intra-ocular lens - In vitro prevention of re-growth of pig and rabbit lens capsule epithelial cells

    NARCIS (Netherlands)

    van Kooten, Theo G.; Koopmans, Steven; Terwee, Thom; Norrby, Sverker; Hooymans, J. M. M.; Busscher, Henk J.

    2006-01-01

    Cataract surgery is routinely performed to replace the clouded lens by a rigid polymeric intra-ocular lens unable to accommodate. By implanting a silicone gel into an intact capsular bag the accommodating properties of the natural lens can be maintained or enhanced. The implantation success of accom

  3. A role for smoothened during murine lens and cornea development.

    Directory of Open Access Journals (Sweden)

    Janet J Y Choi

    Full Text Available Various studies suggest that Hedgehog (Hh signalling plays roles in human and zebrafish ocular development. Recent studies (Kerr et al., Invest Ophthalmol Vis Sci. 2012; 53, 3316-30 showed that conditionally activating Hh signals promotes murine lens epithelial cell proliferation and disrupts fibre differentiation. In this study we examined the expression of the Hh pathway and the requirement for the Smoothened gene in murine lens development. Expression of Hh pathway components in developing lens was examined by RT-PCR, immunofluorescence and in situ hybridisation. The requirement of Smo in lens development was determined by conditional loss-of-function mutations, using LeCre and MLR10 Cre transgenic mice. The phenotype of mutant mice was examined by immunofluorescence for various markers of cell cycle, lens and cornea differentiation. Hh pathway components (Ptch1, Smo, Gli2, Gli3 were detected in lens epithelium from E12.5. Gli2 was particularly localised to mitotic nuclei and, at E13.5, Gli3 exhibited a shift from cytosol to nucleus, suggesting distinct roles for these transcription factors. Conditional deletion of Smo, from ∼E12.5 (MLR10 Cre did not affect ocular development, whereas deletion from ∼E9.5 (LeCre resulted in lens and corneal defects from E14.5. Mutant lenses were smaller and showed normal expression of p57Kip2, c-Maf, E-cadherin and Pax6, reduced expression of FoxE3 and Ptch1 and decreased nuclear Hes1. There was normal G1-S phase but decreased G2-M phase transition at E16.5 and epithelial cell death from E14.5-E16.5. Mutant corneas were thicker due to aberrant migration of Nrp2+ cells from the extraocular mesenchyme, resulting in delayed corneal endothelial but normal epithelial differentiation. These results indicate the Hh pathway is required during a discrete period (E9.5-E12.5 in lens development to regulate lens epithelial cell proliferation, survival and FoxE3 expression. Defective corneal development occurs

  4. Reconstruction of Clear-PEM data with STIR

    CERN Document Server

    Martins, M V; Rodrigues, P; Trindade, A; Oliveira, N; Correia, M; Cordeiro, H; Ferreira, N C; Varela, J; Almeida, P

    2006-01-01

    The Clear-PEM scanner is a device based on planar detectors that is currently under development within the Crystal Clear Collaboration, at CERN. The basis for 3D image reconstruction in Clear-PEM is the software for tomographic image reconstruction (STIR). STIR is an open source object-oriented library that efficiently deals with the 3D positron emission tomography data sets. This library was originally designed for the traditional cylindrical scanners. In order to make its use compatible with planar scanner data, new functionalities were introduced into the library's framework. In this work, Monte Carlo simulations of the Clear-PEM scanner acquisitions were used as input for image reconstruction with the 3D OSEM algorithm available in STIR. The results presented indicate that dual plate PEM data can be accurately reconstructed using the enhanced STIR framework.

  5. Molecular Air Data Clear Air Turbulence Sensor: MADCAT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear air turbulence (CAT), often referred to as "air pockets," is attributed to Kelvin-Helmholtz instabilities at altitudes generally above 18,000ft, often in the...

  6. Molecular Air Data Clear Air Turbulence Sensor: MADCAT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear air turbulence (CAT), often referred to as "air pockets," is attributed to Kelvin-Helmholtz instabilities at altitudes usually above 18,000ft, often without...

  7. Growth and differentiation of human lens epithelial cells in vitro on matrix

    Science.gov (United States)

    Blakely, E. A.; Bjornstad, K. A.; Chang, P. Y.; McNamara, M. P.; Chang, E.; Aragon, G.; Lin, S. P.; Lui, G.; Polansky, J. R.

    2000-01-01

    PURPOSE: To characterize the growth and maturation of nonimmortalized human lens epithelial (HLE) cells grown in vitro. METHODS: HLE cells, established from 18-week prenatal lenses, were maintained on bovine corneal endothelial (BCE) extracellular matrix (ECM) in medium supplemented with basic fibroblast growth factor (FGF-2). The identity, growth, and differentiation of the cultures were characterized by karyotyping, cell morphology, and growth kinetics studies, reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, and Western blot analysis. RESULTS: HLE cells had a male, human diploid (2N = 46) karyotype. The population-doubling time of exponentially growing cells was 24 hours. After 15 days in culture, cell morphology changed, and lentoid formation was evident. Reverse transcription-polymerase chain reaction (RT-PCR) indicated expression of alphaA- and betaB2-crystallin, fibroblast growth factor receptor 1 (FGFR1), and major intrinsic protein (MIP26) in exponential growth. Western analyses of protein extracts show positive expression of three immunologically distinct classes of crystallin proteins (alphaA-, alphaB-, and betaB2-crystallin) with time in culture. By Western blot analysis, expression of p57(KIP2), a known marker of terminally differentiated fiber cells, was detectable in exponential cultures, and levels increased after confluence. MIP26 and gamma-crystallin protein expression was detected in confluent cultures, by using immunofluorescence, but not in exponentially growing cells. CONCLUSIONS: HLE cells can be maintained for up to 4 months on ECM derived from BCE cells in medium containing FGF-2. With time in culture, the cells demonstrate morphologic characteristics of, and express protein markers for, lens fiber cell differentiation. This in vitro model will be useful for investigations of radiation-induced cataractogenesis and other studies of lens toxicity.

  8. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    Science.gov (United States)

    Salleh, H.; Samat, S. B.; Matori, M. K.; Isa, M. J. M.

    2015-09-01

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

  9. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    Energy Technology Data Exchange (ETDEWEB)

    Salleh, H.; Matori, M. K.; Isa, M. J. M. [Agensi Nuklear Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Samat, S. B. [Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

  10. Evaluation of resources for contact lens practice in private contact lens clinics of Muscat, Oman

    Directory of Open Access Journals (Sweden)

    Rajiv Khandekar

    2009-01-01

    Materials and Methods: This study was conducted between May and July 2006. A team of optometrists and health inspectors visited clinics and collected information about the infrastructure, available human resources, and materials used in the CL practice. We used a pre-tested close-ended questionnaire to collect responses of the practitioners and observations of the field staff. Statistical Method: Univariate parametric type of analysis. Results: The team visited 67 CL clinics and interviewed 75 CL practitioners. Proper hand washing facility was available at 61 clinics. Thirty-nine practitioners had> 10 years of experience in dispensing contact lenses. Only 13 clinics had a bio-microscope. None of the clinics had legal documents signed by both providers and end users of the contact lens. Conclusions: Contact lens has received less attention in areas outside the developed world. The CL practice in the private sectors of Oman needs to be strengthened. Minimum standards, standard operating procedures for CL practice, and its periodic supervision would be useful.

  11. Evaluating the cytotoxicity of contact lens multi-purpose solutions in an in vitro lens system

    Directory of Open Access Journals (Sweden)

    O. Matthew Oriowo

    2009-12-01

    Full Text Available Purpose: To investigate the relative cytotoxic effects of contact lens multipurpose solutions on cultured crystalline lenses.Methods: A comparison of the fluorescence emission levels of cultured bovine lenses as affected by three hour experimental exposure to three contact lens multipurpose solutions (COMPLETE Moisture Plus, AMO; OPTI-FREE Express, Alcon; and ReNu MultiPlus, Bausch & Lomb was carried out. The pre- and post-exposure fluorescence levels of the lenses were obtained and values were compared to baseline and control measurements.Results: The solutions yielded varying degrees of cytotoxicity, demonstrating significant (p < 0.01 reversible reduction of cellular viability levels of the cultured crystalline lenses as revealed by the degree of fluorescence emissions in the following order (OPTI-FREE Express > ReNu MultiPlus > COMPLETE MoisturePlus multi-purpose solutionsConclusions: The results show that OPTI-FREE Express and ReNu MultiPlus solutions exhibited more cytotoxic effect compared to COMPLETE MoisturePlus solution. The findings support reportsfrom previous clinical and laboratory studies. These results suggest that the in vitro approach herein presented would be a valuable system for relatively inexpensive and repeatable laboratory investigations of the possible ocular surface reactions of ophthal-mic solutions, cosmetics and pharmaceuticals at pre- and during commercial phases. 

  12. Negative refractive perfect lens vs Spherical geodesic lens. Perfect Imaging comparative analysis

    CERN Document Server

    Gonzalez, Juan C; Minano, Juan C; Grabovickic, Dejan

    2012-01-01

    Negative Refractive Lens (NRL) has shown that an optical system can produce images with details below the classic Abbe diffraction limit. This optical system transmits the electric field, emitted by the object surface, towards the image surface producing the same field distribution in both surfaces. In particular, a Dirac delta electric field in the object surface is focused without diffraction limit to the Dirac delta electric field in the image surface. The Maxwell Fish Eye lens (MFE) and the Spherical Geodesic Waveguide (SGW) have been claimed to break the diffraction limit using positive refraction with a different meaning. In these cases, it has been considered the power transmission from a point source to a point receptor, which falls drastically when the receptor is displaced from the focus by a distance much smaller than the wavelength. Although these systems can detect displacements up to Wavelength/500, they cannot be compared to the NRL, since the concept of the object and image surface is not esta...

  13. Terahertz 3D printed diffractive lens matrices for field-effect transistor detector focal plane arrays.

    Science.gov (United States)

    Szkudlarek, Krzesimir; Sypek, Maciej; Cywiński, Grzegorz; Suszek, Jarosław; Zagrajek, Przemysław; Feduniewicz-Żmuda, Anna; Yahniuk, Ivan; Yatsunenko, Sergey; Nowakowska-Siwińska, Anna; Coquillat, Dominique; But, Dmytro B; Rachoń, Martyna; Węgrzyńska, Karolina; Skierbiszewski, Czesław; Knap, Wojciech

    2016-09-05

    We present the concept, the fabrication processes and the experimental results for materials and optics that can be used for terahertz field-effect transistor detector focal plane arrays. More specifically, we propose 3D printed arrays of a new type - diffractive multi-zone lenses of which the performance is superior to that of previously used mono-zone diffractive or refractive elements and evaluate them with GaN/AlGaN field-effect transistor terahertz detectors. Experiments performed in the 300-GHz atmospheric window show that the lens arrays offer both a good efficiency and good uniformity, and may improve the signal-to-noise ratio of the terahertz field-effect transistor detectors by more than one order of magnitude. In practice, we tested 3 × 12 lens linear arrays with printed circuit board THz detector arrays used in postal security scanners and observed significant signal-to-noise improvements. Our results clearly show that the proposed technology provides a way to produce cost-effective, reproducible, flat optics for large-size field-effect transistor THz-detector focal plane arrays.

  14. Remembering the "lens": visual transformations of a concept from Heider to Brunswik.

    Science.gov (United States)

    Wieser, Martin

    2014-05-01

    It is argued that Frederic Bartlett's views on the social and cultural determinants of remembering and recognition provide a useful background for analyzing the transformations of psychological concepts and images when they are introduced into new academic collectives. An example of a "Bartlettian" view on the history of psychology is given by reconstructing and contextualizing the transformation of the "lens," a model of human perception that was invented by Fritz Heider in the 1920s and adopted by Egon Brunswik from the 1930s onwards. Heider's early work suggested a new perspective on the epistemological relation between subject, media, and object that was devised to create a new conceptual foundation for academic psychology. Brunswik, on the other hand, transformed Heider's "lens" into a clear-cut experimental framework that was based on the physicalist and operationalist demands of logical empiricism, the movement for the "unity of science," and, after his migration to Berkeley, neobehaviorism. This episode provides many similarities with Bartlett's theory of the social determinants of knowledge and the shaping power of collective presuppositions, norms, and ideals.

  15. Cx43, ZO-1, alpha-catenin and beta-catenin in cataractous lens epithelial cells

    Indian Academy of Sciences (India)

    Anshul I Arora; Kaid Johar; Devarshi U Gajjar; Darshini A Ganatra; Forum B Kayastha; Anuradha K Pal; Alpesh R Patel; Rajkumar S; Abhay R Vasavada

    2012-12-01

    Specimens of the anterior lens capsule with an attached monolayer of lens epithelial cells (LECs) were obtained from patients (=52) undergoing cataract surgery. Specimens were divided into three groups based on the type of cataract: nuclear cataract, cortical cataract and posterior subcapsular cataract (PSC). Clear lenses (=11) obtained from donor eyes were used as controls. Expression was studied by immunofluorescence, real-time PCR and Western blot. Statistical analysis was done using the student’s -test. Immunofluorescence results showed punctate localization of Cx43 at the cell boundaries in controls, nuclear cataract and PSC groups. In the cortical cataract group, cytoplasmic pools of Cx43 without any localization at the cell boundaries were observed. Real-time PCR results showed significant up-regulation of Cx43 in nuclear and cortical cataract groups. Western blot results revealed significant increase in protein levels of Cx43 and significant decrease of ZO-1 in all three cataract groups. Protein levels of alpha-catenin were decreased significantly in nuclear and cortical cataract group. There was no significant change in expression of beta-catenin in the cataractous groups. Our findings suggest that ZO-1 and alpha-catenin are important for gap junctions containing Cx43 in the LECs. Alterations in cell junction proteins may play a role during formation of different types of cataract.

  16. Study of Gravitational Lens Chromaticity from Ground-based Narrow Band Photometry

    CERN Document Server

    Mosquera, Ana M; Mediavilla, Evencio; Kochanek, Christopher S

    2010-01-01

    We present observations of wavelength-dependent flux ratios for 4 gravitational lens systems (SDSS~J1650+4251, HE~0435$-$1223, FBQ 0951+2635, and Q~0142$-$100) obtained with the Nordic Optical telescope (NOT). The use of narrow band photometry, as well as the excellent seeing conditions during the observations, allow us to set good baselines to study their chromatic behavior. For SDSS~J1650+4251 we determine the extinction curve of the dust in the $z_L=0.58$ lens galaxy, and find that the 2175 \\AA \\ feature is absent. In the case of HE~0435$-$1223 we clearly detect chromatic microlensing. This allows us to estimate the wavelength dependent size of the accretion disk. We found an R-band disk size of $r^{R}_s=13\\pm5$ light days for a linear prior on $r^{R}_s$ and of $r^{R}_s=7\\pm6$ light days for a logarithmic prior. For a power law size-wavelength scaling of $r_s\\propto\\lambda^{p}$, we were able to constrain the value of the exponent to $p=1.3\\pm0.3$ for both $r^{R}_s$ priors, which is in agreement with the te...

  17. Global horizontal irradiance clear sky models : implementation and analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Hansen, Clifford W.; Reno, Matthew J.

    2012-03-01

    Clear sky models estimate the terrestrial solar radiation under a cloudless sky as a function of the solar elevation angle, site altitude, aerosol concentration, water vapor, and various atmospheric conditions. This report provides an overview of a number of global horizontal irradiance (GHI) clear sky models from very simple to complex. Validation of clear-sky models requires comparison of model results to measured irradiance during clear-sky periods. To facilitate validation, we present a new algorithm for automatically identifying clear-sky periods in a time series of GHI measurements. We evaluate the performance of selected clear-sky models using measured data from 30 different sites, totaling about 300 site-years of data. We analyze the variation of these errors across time and location. In terms of error averaged over all locations and times, we found that complex models that correctly account for all the atmospheric parameters are slightly more accurate than other models, but, primarily at low elevations, comparable accuracy can be obtained from some simpler models. However, simpler models often exhibit errors that vary with time of day and season, whereas the errors for complex models vary less over time.

  18. Coastal sediment elevation change following anthropogenic mangrove clearing

    Science.gov (United States)

    Hayden, Heather L.; Granek, Elise F.

    2015-11-01

    Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment "traps" catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five study sites, each containing paired intact (+mangrove) and cleared (-mangrove) plots. Five sediment elevation pins were deployed in each plot: behind areas cleared of mangroves (-mangrove) and behind adjacent intact mangroves (+mangrove). Sediment elevation increased at intact mangrove sites (M = +3.83 mm, SE = 0.95) whereas cleared mangrove areas suffered elevation loss (M = -7.30 mm, SE = 3.38). Mangroves inshore of partial or continuous gaps in the adjacent fringing reefs had higher rates of elevation loss (M = -15.05 mm) than mangroves inshore of continuous fringing reefs (M = -1.90 mm). Our findings provide information on potential effects of mangrove clearing and the role of offshore habitat characteristics on coastal sediment trapping and maintenance of sediment elevation by mangroves. With implications for coastline capacity to adjust to sea level rise, these findings are relevant to management of coastal fringing mangrove forests across the Caribbean.

  19. Monitoring the eye lens: which dose quantity is adequate?

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, R [Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig (Germany); Dietze, G, E-mail: rolf.behrens@ptb.d [Paracelsusstrasse 7, D-38116 Braunschweig (Germany)

    2010-07-21

    Recent epidemiological studies suggest a rather low dose threshold (below 0.5 Gy) for the induction of a cataract of the eye lens. Some other studies even assume that there is no threshold at all. Therefore, protection measures have to be optimized and current dose limits for the eye lens may be reduced in the future. The question of which personal dose equivalent quantity is appropriate for monitoring the dose to the eye lens arises from this situation. While in many countries dosemeters calibrated in terms of the dose equivalent quantity H{sub p}(0.07) have been seen as being adequate for monitoring the dose to the eye lens, this might be questionable in the case of reduced dose limits and, thus, it may become necessary to use the dose equivalent quantity H{sub p}(3) for this purpose. To discuss this question, the dose conversion coefficients for the equivalent dose of the eye lens (in the following eye lens dose) were determined for realistic photon and beta radiation fields and compared with the values of the corresponding conversion coefficients for the different operational quantities. The values obtained lead to the following conclusions: in radiation fields where most of the dose comes from photons, especially x-rays, it is appropriate to use dosemeters calibrated in terms of H{sub p}(0.07) on a slab phantom, while in other radiation fields (dominated by beta radiation or unknown contributions of photon and beta radiation) dosemeters calibrated in terms of H{sub p}(3) on a slab phantom should be used. As an alternative, dosemeters calibrated in terms of H{sub p}(0.07) on a slab phantom could also be used; however, in radiation fields containing beta radiation with the end point energy near 1 MeV, an overestimation of the eye lens dose by up to a factor of 550 is possible.

  20. Flocculants application for precipitation and separation of proteins from Lens culinaris cv. Tina

    Directory of Open Access Journals (Sweden)

    Barbara Baraniak

    2009-06-01

    Full Text Available Background. Lentil (Lens culinaris is an important crop in many developing countries. Usefulness of protein isolates in the human nutrition and animal feeding have been also studied. Improvement of protein precipitation and fractionation efficiency by using different flocculants was the aim of this study. Material and methods. The polyelectrolytes Magnafloc LT-22 and Magnafloc LT-25 were tested in the process of coagulation and fractionation of protein from lentil protein extracts. Proteins were extracted from flour with 0.5 M NaCl in the 50 mM Tris-HCl buffer pH 7.5 and 2 mM NaOH at ratio 1:10. Protein were coagulated at different pH (6, 5, 4, 3 using flocculants in three different concentration 0.1, 0.3 and 0.5%. Samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results. Influence of extraction medium on the yield and quality of protein was visible. In all studied cases proteins were the most effective precipitated with Magnofloc LT-25. Application of different pH condition for coagulation caused fractionation of lentil protein. Gel electrophoresis of protein of all studied samples showed different molecular weight subunit patterns ranging from 8 to 102 kDa. Conclusions. Using of flocculants as coagulating factors allows obtaining a high concentrated protein isolates, however the yields of flocculation were determined by different extraction systems, concentration of flocculants and pH condition of process.

  1. LensPerfect Analysis of Abell 1689

    Science.gov (United States)

    Coe, Dan A.

    2007-12-01

    I present the first massmap to perfectly reproduce the position of every gravitationally-lensed multiply-imaged galaxy detected to date in ACS images of Abell 1689. This massmap was obtained using a powerful new technique made possible by a recent advance in the field of Mathematics. It is the highest resolution assumption-free Dark Matter massmap to date, with the resolution being limited only by the number of multiple images detected. We detect 8 new multiple image systems and identify multiple knots in individual galaxies to constrain a grand total of 168 knots within 135 multiple images of 42 galaxies. No assumptions are made about mass tracing light, and yet the brightest visible structures in A1689 are reproduced in our massmap, a few with intriguing positional offsets. Our massmap probes radii smaller than that resolvable in current Dark Matter simulations of galaxy clusters. And at these radii, we observe slight deviations from the NFW and Sersic profiles which describe simulated Dark Matter halos so well. While we have demonstrated that our method is able to recover a known input massmap (to limited resolution), further tests are necessary to determine the uncertainties of our mass profile and positions of massive subclumps. I compile the latest weak lensing data from ACS, Subaru, and CFHT, and attempt to fit a single profile, either NFW or Sersic, to both the observed weak and strong lensing. I confirm the finding of most previous authors, that no single profile fits extremely well to both simultaneously. Slight deviations are revealed, with the best fits slightly over-predicting the mass profile at both large and small radius. Our easy-to-use software, called LensPerfect, will be made available soon. This research was supported by the European Commission Marie Curie International Reintegration Grant 017288-BPZ and the PNAYA grant AYA2005-09413-C02.

  2. The Lens Staring You in the Face

    Science.gov (United States)

    vachon, R. W.

    2012-12-01

    When you are embedded in the minutia of a science, you and your collaborators don't need to be convinced that there are benefits to investigating your precise science. You are intrinsically invested. In fact, we spend so much time around each other that we create our own language. So many acronyms that we come to take for granted and topic relevant words, like "fractionate", are not common parlance. This is the case with any specialization, but when it becomes second nature to communicate your work with these norms, transmission breaks down, people tune out, and some audiences become frustrated. Media can cushion this separation, but what do you do when you are the one in front of the camera, and clarity and impact of a concept rests on your shoulders? Just as writing a peer review paper is an acquired skill, so is communicating to the ones who pay many of our salaries, taxpayers. Over the past three years I have worked intimately with publishers, networks and university outreach programs to refine my approach to communicating scientific knowledge to particular audiences. The road has positioned me as interviewee, motivational speaker for science, technology, engineering and math (STEM) in middle and high schools, and educational video series host. Media has their own standards. Personality and enthusiasm may be just as important as the journal into which your findings were published. This presentation will emphasize the audience-adjustable tenants that have stood the test of time to result in effective video communication. Additionally, preparation for and execution of different roles in front of the lens will be discussed.Communicating concepts on video

  3. New trends in intraocular lens imaging

    Science.gov (United States)

    Millán, María S.; Alba-Bueno, Francisco; Vega, Fidel

    2011-08-01

    As a result of modern technological advances, cataract surgery can be seen as not only a rehabilitative operation, but a customized procedure to compensate for important sources of image degradation in the visual system of a patient, such as defocus and some aberrations. With the development of new materials, instruments and surgical techniques in ophthalmology, great progress has been achieved in the imaging capability of a pseudophakic eye implanted with an intraocular lens (IOL). From the very beginning, optical design has played an essential role in this progress. New IOL designs need, on the one hand, theoretical eye models able to predict optical imaging performance and on the other hand, testing methods, verification through in vitro and in vivo measurements, and clinical validation. The implant of an IOL requires a precise biometry of the eye, a prior calculation from physiological data, and an accurate position inside the eye. Otherwise, the effects of IOL calculation errors or misplacements degrade the image very quickly. The incorporation of wavefront aberrometry into clinical ophthalmology practice has motivated new designs of IOLs to compensate for high order aberrations in some extent. Thus, for instance, IOLs with an aspheric design have the potential to improve optical performance and contrast sensitivity by reducing the positive spherical aberration of human cornea. Monofocal IOLs cause a complete loss of accommodation that requires further correction for either distance or near vision. Multifocal IOLs address this limitation using the principle of simultaneous vision. Some multifocal IOLs include a diffractive zone that covers the aperture in part or totally. Reduced image contrast and undesired visual phenomena, such as halos and glare, have been associated to the performance of multifocal IOLs. Based on a different principle, accommodating IOLs rely on the effort of the ciliary body to increase the effective power of the optical system of the

  4. Novel fabrication technique of hybrid structure lens array for 3D images

    Science.gov (United States)

    Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Won, Yong Hyub

    2016-03-01

    Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

  5. The Effects of Opaque and Clear Pit and Fissure Sealants on Infrared Laser Fluorescence Measurements

    Science.gov (United States)

    Bahrololoomi, Z.; Khodabakhsh, M.; Khaksar, Y.

    2014-01-01

    Statement of the Problem: The purpose of placing sealants is to inhibit caries by physical closure of the pits and fissures of teeth. A device named DIAGNOdent is useful in detecting occlusal caries by employing laser fluorescence (LF). However, there are contradictory results in the influence of sealants on LF measurements. Purpose: The aim of this study is to investigate the effects of two different types of fissure sealants on LF measurements. Materials and Method: In this in vitro study, 86 extracted permanent third molars were divided randomly into two groups and clear or opaque sealant was applied on the occlusal surfaces. Two examiners performed pre- and post-seal fluorescence measurements twice with one week interval by employing DIAGNOdent device. Finally, measured values were evaluated through the statistical paired t-test by means of SPSS 17 software. Results: The mean value of LF measurements increased significantly due to the application of clear sealant (p= 0.001) while the statistical changes in this measurement was negligible after applying opaque sealant (p= 0.311). Conclusion: Clear sealants increase the LF measured values but opaque sealants cause almost no changes. Therefore, DIAGNOdent device is not reliable for detecting caries beneath the clear sealant. PMID:24883342

  6. The Effects of Opaque and Clear Pit and Fissure Sealants on Infrared Laser Fluorescence Measurements

    Directory of Open Access Journals (Sweden)

    Bahrololoomi Z.

    2013-10-01

    Full Text Available Statement of the Problem: The purpose of placing sealants is to inhibit caries by physical closure of the pits and fissures of teeth. A device named DIAGNOdent is useful in detecting occlusal caries by employing laser fluorescence (LF. However, there are contradictory results in the influence of sealants on LF measurements. Purpose: The aim of this study is to investigate the effects of two different types of fissure sealants on LF measurements. Materials and Method: In this in vitro study, 86 extracted permanent third molars were divided randomly into two groups and clear or opaque sealant was applied on the occlusal surfaces. Two examiners performed pre and post-seal fluorescence measurements twice with one week interval by employing DIAGNOdent device. Finally, measured values were evaluated through the statistical paired t-test by means of SPSS 17 software. Results: The mean value of LF measurements increased significantly due to the application of clear sealant (p= 0.001 while the statistical changes in this measurement is negligible after applying opaque sealant (p= 0.311. Conclusion: Clear sealants increase the LF measured values but opaque sealants cause almost no changes. Therefore DIAGNOdent device is not reliable for detecting caries beneath the clear sealant.

  7. A comparison between radiovisiography and clearing technique in the study of the root canal types

    Institute of Scientific and Technical Information of China (English)

    Daming Wu; Younong Wu

    2005-01-01

    Objective: To compare the radiovisiography (RVG) with the clearing technique using Kappa value in the study of the root canal types. Methods: One hundred recently extracted human maxillary first premolars were used. Standard periapical RVG images were taken from a buccolingual and mesiodistal direction. The specimens were then accessed, injected with ink, demineralized,dehydrated, and finally were cleared. The RVG images and the transparent teeth were examined by a trained endodontist, and the date of root canal types following Wu's classification was collected. Results: The reliability of RVG was high for studies on simple root canals,but was poor for the studies on the multiple root canals. The Kappa value between the two techniques was 0.3793, indicating the agreement was poor. Conclusion: It is concluded that the limited value of RVG alone when studying certain aspect of the root canal system. The resolution of the RVG system should be enhanced.

  8. Final Radiological Assessment of External Exposure for CLEAR-Line Americium Recovery Operations

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Adam C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Belooussova, Olga N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hetrick, Lucas Duane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-12

    Los Alamos National Laboratory is currently planning to implement an americium recovery program. The americium, ordinarily isotopically pure 241Am, would be extracted from existing Pu materials, converted to an oxide and shipped to support fabrication of americium oxide-beryllium neutron sources. These operations would occur in the currently proposed Chloride Extraction and Actinide Recovery (CLEAR) line of glove boxes. This glove box line would be collocated with the currently-operational Experimental Chloride Extraction Line (EXCEL). The focus of this document is to provide an in-depth assessment of the currently planned radiation protection measures and to determine whether or not further design work is required to satisfy design-goal and ALARA requirements. Further, this document presents a history of americium recovery operations in the Department of Energy and high-level descriptions of the CLEAR line operations to provide a basis of comparison. Under the working assumptions adopted by this study, it was found that the evaluated design appears to mitigate doses to a level that satisfies the ALARA-in-design requirements of 10 CFR 835 as implemented by the Los Alamos National Laboratory procedure P121. The analyses indicate that extremity doses would also meet design requirements. Dose-rate calculations were performed using the radiation transport code MCNP5 and doses were estimated using a time-motion study developed in consort with the subject matter expert. A copy of this report and all supporting documentation are located on the Radiological Engineering server at Y:\\Rad Engineering\\2013 PROJECTS\\TA-55 Clear Line.

  9. [Glycation of lens proteins in diabetes and its non-invasive assessment - first experience in the Czech Republic].

    Science.gov (United States)

    Škrha, Jan; Šoupal, Jan; Prázný, Martin; Škrha, Jan

    2015-04-01

    Advanced glycation end-products (AGEs) play a crucial role in the pathogenesis of diabetes and its complications. Their accumulation in the lens reflects total glycation rate in the human body. Recently, a new confocal biomicroscope ClearPath DS-120 quickly measuring lens autofluorescence (LAF) has been developed. Our pilot study included 69 patients with diabetes and 49 healthy controls, in all subject LAF was measured and compared with skin autofluorescence (SAF) assessed by AGE-Reader. Both LAF (T1DM: 0,27 ± 0,09; T2DM: 0,22 ± 0,06; controls: 0,17 ± 0,04 AU; p glycated hemoglobin (HbA1c) was rather poor, since HbA1c cannot wholly reflect long-term glycation process. Lens autofluorescence could be a robust marker of long-term diabetes control predicting future complication risks. However, confirmation of such hypothesis will need other and long-term clinical studies.

  10. A Spectroscopically Confirmed Double Source Plane Lens System in the Hyper Suprime-Cam Subaru Strategic Program

    CERN Document Server

    Tanaka, Masayuki; More, Anupreeta; Dezuka, Arsha; Egami, Eiichi; Oguri, Masamune; Suyu, Sherry H; Sonnenfeld, Alessandro; Higuchi, Ryou; Komiyama, Yutaka; Miyazaki, Satoshi; Onoue, Masafusa; Oyamada, Shuri; Utsumi, Yousuke

    2016-01-01

    We report the serendipitous discovery of HSC J142449-005322, a double source plane lens system in the Hyper Suprime-Cam Subaru Strategic Program. We dub the system Eye of Horus. The lens galaxy is a very massive early-type galaxy with stellar mass of ~7x10^11 Msun located at z_L=0.795. The system exhibits two arcs/rings with clearly different colors, including several knots. We have performed spectroscopic follow-up observations of the system with FIRE on Magellan. The outer ring is confirmed at z_S2=1.988 with multiple emission lines, while the inner arc and counterimage is confirmed at z_S1=1.302. This makes it the first double source plane system with spectroscopic redshifts of both sources. Interestingly, redshifts of two of the knots embedded in the outer ring are found to be offset by delta_z=0.002 from the other knots, suggesting that the outer ring consists of at least two distinct components in the source plane. We perform lens modeling with two independent codes and successfully reproduce the main f...

  11. Visual and Refractive Outcomes of a Toric Presbyopia-Correcting Intraocular Lens

    Science.gov (United States)

    Epitropoulos, Alice T.

    2016-01-01

    Purpose. To evaluate outcomes in astigmatic patients implanted with the Trulign (Bausch + Lomb) toric presbyopia-correcting intraocular lens (IOL) during cataract surgery in a clinical practice setting. Methods. Retrospective study in 40 eyes (31 patients) that underwent cataract extraction and IOL implantation in a procedure using intraoperative wavefront aberrometry guidance (ORA system). Endpoints included uncorrected visual acuity (VA), reduction in refractive cylinder, accuracy to target, axis orientation, and safety. Results. At postoperative month 1, refractive cylinder was ≤0.50 D in 97.5% of eyes (≤1.00 D in 100%), uncorrected distance VA was 20/25 or better in 95%, uncorrected intermediate VA was 20/25 or better in 95%, and uncorrected near VA was 20/40 (J3 equivalent) or better in 92.5%. Manifest refraction spherical equivalent was within 1.00 D of target in 95% of eyes and within 0.50 D in 82.5%. Lens rotation was <5° and best-corrected VA was 20/25 or better in all eyes. Conclusion. The IOL effectively reduced refractive cylinder and provided excellent uncorrected distance and intermediate vision and functional near vision. Refractive predictability and rotational stability were exceptional. Implantation of this toric presbyopia-correcting IOL using ORA intraoperative aberrometry provides excellent refractive and visual outcomes in a standard of care setting. PMID:26885382

  12. Imaging of aphakic intraocular lens with a slit-scanning tomography system

    Science.gov (United States)

    Oliveira, Cristina M.; Almeida, J. B.; Franco, S.

    2011-05-01

    Nowadays, cataract extraction with IOL implantation aims not only to restore the crystalline lens' transparency, but also to improve patients' retinal image quality. The refractive outcome and visual quality in pseudophakic eyes is mainly determined by the combination of corneal and internal optics resulting from the implanted IOLs. The optical function of the IOLs depends on its position in the eye. The IOL distance to the corneal apex determines the optical power needed for optical correction. In this paper it is described the usage of a slit-scanning imaging system to determine IOL positioning. Through the projection of the light from a slit onto the eye, this tomography system allows to acquire multiple sections of the anterior eye segment, at different meridians. The developed system's software corrects geometric and optical distortion of the images and provides 3-dimentional models of the eye's structures from the 2-dimensional sections. With this noninvasive technique, cross-sectional images of an eye with an aphakic IOL were obtained in order to reconstruct its 3- dimensional model of the lens and assess its position in the anterior segment camera.

  13. Biocompatibility and cytotoxicity study of nanophotonic rigid gas permeable contact lens material

    Science.gov (United States)

    Tomić, M.; Munćan, J.; Stamenković, D.; Jokanović, M.; Matija, L.

    2013-04-01

    Since materials on nanoscale have different characteristics from materials on macro scale their biocompatibility should be precisely and specifically investigated. Fullerenes, the third carbon allotrope, are one of the most used nanomaterials. The least stable and the most common is fullerene C60. One of the main disadvantages of fullerene is its low solubility in water. In order to make it soluble, it must be functionalized with polar groups such as -OH and -COOH. From all the water soluble fullerenes the most important ones are those with -OH groups attached named fullerols. We have developed new materials for contact lenses by adding fullerene (C60) and fullerol (C60(OH)24) into PMMA. The aim of our investigation was to compare the influences of those materials on aqueous solutions similar to tear film. For the analysis of the solutions we used opto-magnetic imaging and IR spectroscopy. The acquired spectrums were commented and compared with the standard contact lens material, which was analyzed by the same methods. The ISO 10993 cytotoxicity test on extract of nanophotonic material with incorporated C60 was done as well. This research contributes to better understanding of the biocompatibility of new rigid gas permeable contact lens materials.

  14. Beam Dynamics in an Electron Lens with the Warp Particle-in-cell Code

    CERN Document Server

    Stancari, Giulio; Redaelli, Stefano

    2014-01-01

    Electron lenses are a mature technique for beam manipulation in colliders and storage rings. In an electron lens, a pulsed, magnetically confined electron beam with a given current-density profile interacts with the circulating beam to obtain the desired effect. Electron lenses were used in the Fermilab Tevatron collider for beam-beam compensation, for abort-gap clearing, and for halo scraping. They will be used in RHIC at BNL for head-on beam-beam compensation, and their application to the Large Hadron Collider for halo control is under development. At Fermilab, electron lenses will be implemented as lattice elements for nonlinear integrable optics. The design of electron lenses requires tools to calculate the kicks and wakefields experienced by the circulating beam. We use the Warp particle-in-cell code to study generation, transport, and evolution of the electron beam. For the first time, a fully 3-dimensional code is used for this purpose.

  15. Viruses and bacteria in acute asthma exacerbations - A GA(2) LEN-DARE* systematic review

    DEFF Research Database (Denmark)

    Papadopoulos, N G; Christodoulou, I; Rohde, G

    2011-01-01

    and bacteria in acute asthma exacerbations - A GA(2) LEN-DARE systematic review. Allergy 2010; DOI: 10.1111/j.1398-9995.2010.02505.x. ABSTRACT: A major part of the burden of asthma is caused by acute exacerbations. Exacerbations have been strongly and consistently associated with respiratory infections....... Respiratory viruses and bacteria are therefore possible treatment targets. To have a reasonable estimate of the burden of disease induced by such infectious agents on asthmatic patients, it is necessary to understand their nature and be able to identify them in clinical samples by employing accurate...... less or not clearly associated. Mycoplasma and Chlamydophila pneumoniae seem to be involved more with asthma persistence rather than with disease exacerbations. Recent data suggest that common bacteria may also be involved, but this should be confirmed. Although current information is considerable...

  16. Binocular lens treatment in tree shrews: Effect of age and comparison of plus lens wear with recovery from minus lens-induced myopia.

    Science.gov (United States)

    Siegwart, John T; Norton, Thomas T

    2010-11-01

    We examined normal emmetropization and the refractive responses to binocular plus or minus lenses in young (late infantile) and juvenile tree shrews. In addition, recovery from lens-induced myopia was compared with the response to a similar amount of myopia produced with plus lenses in age-matched juvenile animals. Normal emmetropization was examined with daily noncycloplegic autorefractor measures from 11 days after natural eye-opening (days of visual experience [VE]) when the eyes were in the infantile, rapid growth phase and their refractions were substantially hyperopic, to 35 days of VE when the eyes had entered the juvenile, slower growth phase and the refractions were near emmetropia. Starting at 11 days of VE, two groups of young tree shrews wore binocular +4 D lenses (n=6) or -5 D lenses (n=5). Starting at 24 days of VE, four groups of juvenile tree shrews (n=5 each) wore binocular +3 D, +5 D, -3 D, or -5 D lenses. Non-cycloplegic measures of refractive state were made frequently while the animals wore the assigned lenses. The refractive response of the juvenile plus-lens wearing animals was compared with the refractive recovery of an age-matched group of animals (n=5) that were myopic after wearing a -5 D lens from 11 to 24 days of VE. In normal tree shrews, refractions (corrected for the small eye artifact) declined rapidly from (mean±SEM) 6.6±0.6 D of hyperopia at 11 VE to 1.4±0.2 D at 24 VE and 0.8±0.4 D at 35 VE. Plus 4 D lens treatment applied at 11 days of VE initially corrected or over-corrected the young animals' hyperopia and produced a compensatory response in most animals; the eyes became nearly emmetropic while wearing the +4 D lenses. In contrast, plus-lens treatment starting at 24 days of VE initially made the juvenile eyes myopic (over-correction) and, on average, was less effective. The response ranged from no change in refractive state (eye continued to experience myopia) to full compensation (emmetropic with the lens in place

  17. Non-thermal electromagnetic radiation damage to lens epithelium.

    Science.gov (United States)

    Bormusov, Elvira; P Andley, Usha; Sharon, Naomi; Schächter, Levi; Lahav, Assaf; Dovrat, Ahuva

    2008-05-21

    High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35°C for 10-15 days. A novel computer-controlled microwave source was used to investigate the effects of microwave radiation on the lenses. 58 lenses were used in this study. The lenses were divided into four groups: (1) Control lenses incubated in organ culture for 10 to15 days. (2) Electromagnetic radiation exposure group treated with 1.1 GHz, 2.22 mW microwave radiation for 90 cycles of 50 minutes irradiation followed by 10 minutes pause and cultured up to 10 days. (3) Electromagnetic radiation exposure group treated as group 2 with 192 cycles of radiation and cultured for 15 days. (4) Lenses exposed to 39.5°C for 2 hours 3 times with 24 hours interval after each treatment beginning on the second day of the culture and cultured for 11 days. During the culture period, lens optical quality was followed daily by a computer-operated scanning laser beam. At the end of the culture period, control and treated lenses were analyzed morphologically and by assessment of the lens epithelial ATPase activity. Exposure to 1.1 GHz, 2.22 mW microwaves caused a reversible decrease in lens optical quality accompanied by irreversible morphological and biochemical damage to the lens epithelial cell layer. The effect of the electromagnetic radiation on the lens epithelium was remarkably different from those of conductive heat. The results of this investigation showed that electromagnetic fields from microwave radiation have a negative impact on the eye lens. The lens damage by electromagnetic fields was distinctly different from that caused by conductive heat.

  18. Comparison of visual outcomes after implantation of diffractive trifocal toric intraocular lens and a diffractive apodized bifocal toric intraocular lens

    Science.gov (United States)

    Gundersen, Kjell Gunnar; Potvin, Rick

    2016-01-01

    Purpose The aim of this study was to compare a new diffractive trifocal toric lens with an apodized diffractive bifocal toric lens in terms of refractive and visual acuity (VA) outcomes, including low-contrast VA (LCVA), as well as the patient’s visual function 3 months after implantation. Patients and methods This is a randomized prospective study involving bilateral implantation of a trifocal toric or a bifocal toric lens. At 3 months postoperatively, the subject’s vision was tested both uncorrected and with his/her best distance correction at: distance (4 m), intermediate (63 cm), and near (40 cm). Binocular defocus curves were measured with no correction and with the subject’s best distance correction in place. Quality of vision was measured using the National Eye Institute Visual Function Questionnaire. Results A total of 22 patients were enrolled (eleven in each group). There was no statistically significant difference in the absolute change in measured rotation between 1 month and 3 months postoperatively between the two intraocular lens (IOL) groups (P=0.98). At 3 months, the postoperative refraction and distance VA by eye were similar between groups. There was no statistically significant difference in the measured LCVA between groups (P=0.39). The defocus curve showed that at 67 cm, the trifocal toric lens had statistically significantly better VA when compared to the bifocal toric lens. There were no statistically significant differences by group for any of the National Eye Institute Visual Function Questionnaire scores (P>0.26 in all cases). Conclusion The trifocal toric IOL improved the intermediate vision without negatively impacting visual function and distance, near, or low-contrast VA when compared to a bifocal toric IOL. The toric component of the trifocal lens effectively reduced astigmatism and provided good rotational stability. PMID:27051269

  19. Far-field pattern analysis of extended-hemispherical-lens/objective-lens antenna system at millimeter wavelengths

    Science.gov (United States)

    Dou, Wenbin; Sun, Zhong Liang; Zeng, G.

    1998-11-01

    integrated antennas have the advantages of low cost and can be readily mass produced using standard IC fabrication processes. However, integrated antennas suffer from the surface wave effect at millimeter waves. One of the ways to avoid this problem is to integrate the antennas on a dielectric lens. This structure does not support surface-waves and tend to radiate most of their power into the dielectric side making the pattern unidirectional on high dielectric constant lenses. The dielectric lens also provides mechanical rigidity and thermal stability. There are various dielectric lenses which can be used for receiver application. Among them the extended hemispherical lens is very practical, since it can synthesize other lenses such as hemispherical, hyperhemispherical, or ellipsoidal simply by varying the extension length behind the hemispherical position. In reference five, investigation on such antenna/lens system is presented. In reference 6, slot- ring antennas on dielectric lens is investigated. In many applications the extended hemispherical lens/objective lens antenna system is more attractive, because it can provide higher gain and may be used in imaging system. On the other hand, monopulse direction-finding techniques are currently the most accurate and rapid method for locating a target electronically. This antenna system can also be used as monopulse antenna. However, the treatments on such antenna system are not presented yet. In this paper, the radiation pattern of the antenna system fed by double-slot antenna are computed using ray-tracing and diffraction integration methods. Although the double-slot antenna is used as feed antenna, other antenna such as slot-ring, bow-tie antenna can be used too.

  20. A design study of a magnifying magnetic lens for proton radiography

    Institute of Scientific and Technical Information of China (English)

    YANG Guo-Jun; ZHANG Zhuo; WEI Tao; HE Xiao-Zhong; LONG Ji-Dong; SHI Jin-Shui; ZHANG Kai-Zhi

    2012-01-01

    Magnifying magnetic lenses can be used in high-energy proton microscopes.The -I lens suggested by Zumbro is analyzed in this paper,and a new type of magnetic lens called a lengthened lens is introduced.Theoretical analysis shows that the lengthened lens can form a magnifying lens,and at the same time the main advantages of a Zumbro lens are inherited.Using the My-BOC beam dynamics code,an example of the design is shown.The results show that the method of designing magnifying magnetic lenses is effective.