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Sample records for experimental radiation cataract its

  1. Evaluation of calcium dobesilate for its anti-cataract potential in experimental animal models.

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    Velpandian, T; Nirmal, J; Gupta, P; Vijayakumar, A R; Ghose, S

    2010-04-01

    The present study evaluated the protective action of calcium dobesilate (CDO) in various experimental models of cataract. CDO was studied in hydrocortisone-induced cataract in developing chick embryos and selenite-induced cataract in pups. CDO anti-cataract activity was also evaluated after oral and topical application as eye drops in galactose (30%) fed rats. This study was further extended to evaluate the intraocular penetration of a single dose of 1% CDO (50 microL) in rabbits. CDO exhibited significant protection against cataract in experimental models and considerable penetration after single topical application. Anti-cataract activity may be due to its antioxidant as well as aldose reductase inhibitor properties. Further studies are in progress to evaluate its clinical efficacy in diabetic cataract. Copyright 2010 Prous Science, S.A.U. or its licensors. All rights reserved.

  2. Solar ultraviolet radiation cataract.

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    Löfgren, Stefan

    2017-03-01

    Despite being a treatable disease, cataract is still the leading cause for blindness in the world. Solar ultraviolet radiation is epidemiologically linked to cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV radiation-induced cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human cataract. Regardless of the cause for cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens. Copyright © 2016. Published by Elsevier Ltd.

  3. The lens, cataracts and space-related radiations

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    Worgul, B.

    Of considerable moment in the annals of space-related radiation studies is the recent report of radiogenic cataracts among the astronauts (Cucinotta et al., 2002. Rad. Res. 156: 460). Although generally unexpected, the finding was fully predicted by a number of experimental studies on high LET radiation cataractogenesis. Historically, the lens and its primary pathology, cataract, have played important roles in the elucidation of the nuances of the biological response to ioniz ing radiation. So too their study has contributed greatly to an appreciation of the cell and tissue effects of exposure to high - LET radiation . Findings from cataract studies have validated, at the level of complex tissue expression, evidence for extremely large RBEs at low doses and the inverse dose-rate effect observed in other systems. The extensive experiment al studies on radiation cataractogenesis in rodents presaged and predicted the recent report of radiogenic cataracts in the astronaut corps. It is therefore important to revisit and re-evaluate the existing experimental data on lens damage following high-LET radiation exposure. Also given the circumstances, the tissue without question deserves continued investigative exploitation and scrutiny. In addition greater attention should be paid to the potential the lens as a surrogate for tissues less amenable to non - invasive longitudinal examination. Currently the lens and cataract studies are again providing insights into fundamental biological processes while at the same time establishing additional bases for medical follow-up. Among the highly relevant studies are our recent findings which support the concept of a genetic predisposition to radiation sensitivity. Individuals with elevated radiation sensitivity may not be appropriate choices for manned forays into space. Also of particular concern is the potentially complicating influence of the bystander effect/adaptive response for determining risk of developing cataracts from space

  4. Cataract

    Science.gov (United States)

    A cataract is a clouding of the lens in your eye. It affects your vision. Cataracts are very common in older people. By age ... than half of all Americans either have a cataract or have had cataract surgery. A cataract can ...

  5. Modern cataract surgery for radiation-induced cataracts in retinoblastoma.

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    Osman, Ihab M; Abouzeid, Hana; Balmer, Aubin; Gaillard, Marie-Claire; Othenin-Girard, Philippe; Pica, Alessia; Moeckli, Raphaël; Schorderet, Daniel F; Munier, Francis L

    2011-02-01

    Surgery of radiation-induced cataracts in children with retinoblastoma (RB) is a challenge as early intervention is weighted against the need to delay surgery until complete tumour control is obtained. This study analyses the safety and functional results of such surgery. In a retrospective, non-comparative, consecutive case series, we reviewed medical records of RB patients ≤ 14 y of age who underwent either external beam radiotherapy or plaque treatment and were operated for radiation-induced cataract between 1985 and 2008. In total, 21 eyes of 20 RB patients were included and 18 out of the 21 eyes had Reese-Ellsworth stage V or ABC classification group D/E RB. Median interval between last treatment for RB and cataract surgery was 21.5 months, range 3-164 months. Phacoaspiration was performed in 13 eyes (61%), extra-capsular cataract extraction in 8 (39%) and intraocular lens implantation in 19 eyes (90%). The majority of cases, 11/21 (52%), underwent posterior capsulorhexis or capsulotomy and 6/21 (28%) an anterior vitrectomy. Postoperative visual acuity was ≥ 20/200 in 13 eyes and < 20/200 in 5 eyes. Intraocular tumour recurrence was noted in three eyes. Mean postoperative follow up was 90 months ± 69 months. Modern cataract surgery, including clear cornea approach, lens aspiration with posterior capsulotomy, anterior vitrectomy and IOL implantation is a safe procedure for radiation-induced cataract as long as RB is controlled. The visual prognosis is limited by initial tumour involvement of the macula and by corneal complications of radiotherapy. We recommend a minimal interval of 9 months between completion of treatment of retinoblastoma and cataract surgery.

  6. Cosmic Radiation and Cataracts in Airline Pilots

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    Rafnsson, V.; Olafsdottir, E.; Hrafnkelsson, J.; de Angelis, G.; Sasaki, H.; Arnarson, A.; Jonasson, F.

    Nuclear cataracts have been associated with ionising radiation exposure in previous studies. A population based case-control study on airline pilots has been performed to investigate whether employment as a commercial pilot and consequent exposure to cosmic radiation were associated to lens opacification, when adjusted for known risk factors for cataracts. Cases of opacification of the ocular lens were found in surveys among pilots and a random sample of the Icelandic population. Altogether 445 male subjects underwent a detailed eye examination and answered a questionnaire. Information from the airline company on the 79 pilots employment time, annual hours flown per aircraft type, the timetables and the flight profiles made calculation of individual cumulated radiation dose (mSv) possible. Lens opacification were classified and graded according to WHO simplified cataracts grading system using slit lamp. The odds ratio from logistic regression of nuclear cataracts risk among cases and controls was 3.02 (95% CI 1.44 to 6.35) for pilots compared with non-pilots, adjusted for age, smoking and sunbathing habits, whereas that of cortical cataracts risk among cases and controls was lower than unity (non significant) for pilots compared with non-pilots in a logistic regression analysis adjusted for same factors. Length of employment as a pilot and cumulated radiation dose (mSv) were significantly related to the risk of nuclear cataracts. So the association between radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking and sunbathing habits, indicates that cosmic radiation may be cause of nuclear cataract among commercial pilots.

  7. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

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    Kleiman, Norman Jay [Columbia University

    2013-11-30

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

  8. Influence of corticosteroids and vitamin E deficiency on onset of radiation-induced cataract

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    Junk, A. K.; Worgul, B. W.

    Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with, and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of seventy-two 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on standard chow. Fifty per cent of the animals in each nutritional group received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of six months. Cataract onset and development were followed by weekly slit-lamp exam. After six month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks vs. 11 wks in controls ( p Corticosteroids accounted for accelerated cataract development in both irradiated ( p corticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and

  9. Influence of Corticosteroids and Vitamin E Deficiency on Onset and Cytopathology of Radiation-Induced Cataract

    Science.gov (United States)

    Junk, A. K.; Worgul, B. V.

    Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of 72 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on regular chow. In each nutritional group 18 rats additionally received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of 6 months. Cataract onset and development were followed by weekly slit-lamp exam. After 6 month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks versus 11 wks in controls (pCorticosteroids accounted for accelerated cataract development in both irradiated (pcorticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and differentiation.

  10. [Evaluation of calcium dobesilate for its anti-cataract potential in experimental rat models].

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    Zheng, Guang-ying; Jiang, Yu; Wang, Rui-na; Hao, Li-li; Xu, Dong

    2013-10-01

    To investigate the preventive and therapeutic effects of agent calcium dobesilate(CDO) with different doses on the galactose cataract of rats. We chose fifty Wistar rats at 20- day old. Then, they were divided into 3 groups at random. Choose 10 rats as the control group and gave normal diet; 10 rats as the model group and fed with Gal solution ( drink 12.5% Gal solution from 1 to 7 days and 10%Gal solution from 8 to 21 days except for normal diet ) ; 30 rats as the treatment group and fed with the same Gal solution as the model group, besides they were divided into high dosage group, medium dosage group and low dosage group equally and gave 300 mg×kg(-1)×d(-1), 150 mg×kg(-1)×d(-1), 75 mg×kg(-1)×d(-1) dose of calcium dobesilate respectively from the first day to the end of experiment. The experiment lasts 21 days. Lens opacity were observed and recorded by slit-lamp examination regularly. Activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) and content of malondialdehyde (MDA) were determined to estimate the effect of CDO . Lens fibers changes and Histological changes were observed by scanning electron microscope (SEM) and light microscope (LM) separately. The apoptosis rate of lens epithelium were determined by TUNEL assay. The appearance of Lens opacity in model group was more quickly than that in treatment group in model group, 3 eyes in degree IV, 7 eyes in degree V, while in treatment group, 5 eyes in degree III, 3 eyes in degree IV, 2 eyes in degree V (H = 7.12, P < 0.05). The activity of SOD and GSH-px in treatment group is higher than mode group, but lower than control group on 8th day, there was difference noticed in the activity of SOD (50.01 ± 1.19), (39.39 ± 1.70) , treatment group (46.57 ± 1.09, 46.42 ± 0.87, 45.70 ± 1.46) U/mgProt (F = 88.70, P < 0.05) and the activity of GSH-px (42.92 ± 0.97) , (12.70 ± 1.17) , treatment group (29.16 ± 1.05, 29.08 ± 0.98, 28.25 ± 0.98) nmol/mgprot (F = 1071.89, P < 0.05) ]in 3

  11. Cataract and its surgery in Fiji.

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    Brian, Garry; Ramke, Jacqueline; Szetu, John; Qoqonokana, Mundi Qalo

    2011-07-01

    To characterize cataract and its surgery among adults aged ≥40 years in Fiji. Population-based cross-sectional survey using multistage cluster random sampling. 1381 (= 73.0% participation); eight provinces on Viti Levu. Interview-based questionnaire; visual acuity measured; autorefraction; dilated ocular examination. Prevalence; predictors; surgical outcomes. Being Indian (P = 0.001), elderly (P Fiji population aged ≥40 years, prevalence of cataract-induced low vision and blindness were each 1.7% (95% confidence interval [CI] 1.0-2.4%). At least one eye of 4.6% and both of 1.8% participants had surgery (86.4% extracapsular). Gender (P = 0.213), age (P = 0.472) and rural/urban domicile (P = 0.895) were not predictors of surgery among those who required it in at least one eye. After intraocular lens surgery: 50.7% had pupillary posterior capsular opacification; mean spherical equivalent was -1.37 ± 1.95D (range, -6.38 to +2.25D); mean cylindrical error was 2.31 ± 1.75D (range, 0.0 to 8.75D); ≥N8 for 39.5%; ≥6/18 for 56.6%; Fiji population aged ≥40 years, Cataract Surgical Coverage (Person) was 47.5% (95%CI 29.2-65.8%) at Fiji cataract services and outcomes compare favourably with those of neighbouring Papua New Guinea and Timor Leste. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

  12. Cataracts

    Science.gov (United States)

    ... visit HHS USAJobs Home > Statistics and Data > Cataracts Cataracts Cataracts Defined A cataract is a clouding of the ... 2010 2010 U.S. Age-Specific Prevalence Rates for Cataract by Age, and Race/Ethnicity The risk of ...

  13. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

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    Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

    2016-01-27

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis.

  14. Ionizing radiation induced cataract; Katarakt-Induktion durch ionisierende Strahlung

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    Mueller, W.U. [Universitaetsklinikum Essen (Germany). Inst. fuer Medizinische Strahlenbiologie

    2013-07-01

    Until recently it was believed that the cataract (opacity of the eye lens) is a deterministic effect with a dose threshold of several Gray in dependence on the exposure conditions. Studies in Hiroshima and Nagasaki, in the vicinity of Chernobyl, of American radiologic technologists, astronauts, and patients after having received several computer tomographies of the head region, however, have shown that this assumption is not correct. It had been overlooked in the past that with decreasing dose the latency period is increasing. Therefore, the originally available studies were terminated too early. The more recent studies show that, in the case of a threshold existing at all, it is definitely below 0.8 Gy independently of an acute or a chronic exposure. All studies, however, include 0 Gy in the confidence interval, so that the absence of a dose threshold cannot be excluded. The German Commission on Radiological Protection (Strahlenschutzkommission, SSK) suggested therefore among others: targeted recording of the lens dose during activities which are known to be associated with possible significant lens exposure, examination of the lens should be included as appropriate in the medical monitoring of people occupationally exposed to radiation, if there is potentially high lens exposure, adoption of research strategies to develop a basic understanding of the mechanisms underlying radiation induced cataracts. The International Commission on Radiological Protection (ICRP) actually assumes a threshold dose of 0.5 Gy and, based on this assumption, has recommended in 2011 to reduce the dose limit for the eye lens from 150 mSv in a year to 20 mSv in a year for people occupationally exposed to ionising radiation. (orig.)

  15. Cataracts

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    ... vision is a symptom of cataracts. Distortion or ghost images from cataracts. See a simulation of what ... of Refractive Surgery * Required * First Name: * Last Name: Member ID: * Phone Number: * Email: * Enter code: * Message: Thank ...

  16. Radiation-induced cataract-genesis: pathophysiologic, radiobiological and clinical aspects; Catarate radio-induite: aspects physiopathologiques, radiobiologiques et cliniques

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    Belkacemi, Y.; Touboul, E.; Meric, J.B. [Hopital Tenon, Service d' Oncologie-Radiotherapie, 75 - Paris (France); Rat, P.; Warnet, J.M. [Paris-5 Univ., Lab. de Toxicologie, UFR Pharmacie, Unite de Pharmacotoxicologie Cellulaire, Service Pharmacie, 75 (France)

    2001-08-01

    Cataract-genesis is a widely reported late effect of irradiated crystalline lens. In this review the authors discussed the different aspects of radiation cataract pathogenesis, and the different mechanisms involved in the lens opacification, particularly the epithelium modifications such as epithelial cell death. The authors also reported the influence of radiation exposure on cataract formation following total body irradiation (TBI) and autologous or allogeneic bone marrow transplantation for hematologic malignancies. Moreover, the radiobiological parameters are not studied for the crystalline lens of human. We applied for the first time the linear quadratic (LQ) and biological effective dose (BED) concept to TBI data. The calculated value of {alpha}/{beta} of 1 Gy is in the range of the values reported for the other late responding tissues. The other risk factors for cataract development after TBI such as age, gender, central nervous system boost, long-term steroid therapy and heparin administration are discussed. In terms of cataract or sicca syndrome prevention, numerous compounds have been successfully tested in experimental models or used for the prevention of radiation-induced xerostomia in patients treated for head and neck cancer. However, none of them has been clinically evaluated for ocular radiation late effects prevention. In this report the authors discussed some of the radioprotectors potentially interesting for radiation-induced cataract or sicca syndrome prevention. (author)

  17. On radiation emission from a microbunched beam with wavefront tilt and its experimental observation

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    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-06-15

    In this paper we compare experimental observations and theory of radiation emission from a microbunched beam with microbunching wavefront tilt with respect to the direction of motion. The theory refers to the work of T. Tanaka, H. Kitamura, and T. Shintake (2004), which predicts, in this case, exponential suppression of coherent radiation along the kicked direction. The observations refer to a recent experiment performed at the LCLS, where a microbunched beam was kicked by a bend and sent to a radiator undulator. The experiment resulted in the emission of strong coherent radiation that had its maximum along the kicked direction of motion, when the undulator parameter was detuned to a value larger than the nominal one. We first analyze the theory in detail, and we confirm the correctness of its derivation according to the conventional theory of radiation emission from charged particles. Subsequently, we look for possible peculiarities in the experiment, which may not be modeled by the theory. We show that only spurious effects are not accounted for. We conclude that the experiment defies explanation in terms of the conventional theory of radiation emission.

  18. Ophthalmologic survey of atomic bomb survivors in Japan, 1949. Atomic bomb radiation cataract case report with histopathologic study. Medical examination of Hiroshima patients with radiation cataracts

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    Cogan, D.G.; Martin, S.F.; Kimura, S.J.; Ikui, Hiroshi; Fillmore, P.G.

    1959-01-01

    This document contains 3 reports dealing with the delayed effects of radiation on the eyes of survivors of the atomic explosions in Hiroshima and Nagasaki. In the first study, 1000 persons who were listed as having been in the open and within two kilometers of the hypocenter at the time of the explosion were selected at random from the census files of the Atomic Bomb Casualty Commission for study. In addition, 231 others, comprising the total available number of surviving persons listed at present in the census files as having been within one kilometer of the hypocenter, were examined, as were several hundred others who were contacted through newspaper publicity, referrals from local ophthalmologists, or through hearsay. The survey resulted in bringing in persons having, or having had, a variety of ocular conditions. Those connected with the atomic bomb included the following diagnoses; multiple injuries of eyes and eyelids; keratoconjunctivitis from ultraviolet and ionizing radiations; thermal burn of the cornea and of the retina; retinitis proliferans; and radiation cataracts. The cataracts were the only delayed manifestations of ocular injury from the atomic bomb. The second paper is a case report of a histopathologic study of atomic bomb radiation cataract. The third paper presents the results of medical examinations of survivors having radiation induced cataracts. 32 references, 8 figures. (DMC)

  19. Increasing sustainable cataract services in sub-Saharan Africa: an experimental initiative

    Directory of Open Access Journals (Sweden)

    Sasipriya M Karumanchi

    2015-04-01

    Full Text Available To begin to meet the need for cataract surgery in sub-Saharan Africa, the cataract surgical rate (CSR should be at least 2,000 to 3,000; i.e. there should be 2,000-3,000 cataract operations per million population, per year. The current levels are below 1,000 (and often much lower. Sub-Saharan Africa poses a unique set of challenges: low population density; inadequate transportation systems that inhibit access; big differences in wealth; and a shortage of eye care resources (which are usually concentrated in larger cities. Additional issues relate to productivity, the supply chain and the quality of outcomes, all of which contribute to the low cataract surgical rates. It is in this context that the Hilton Foundation sought to enhance cataract surgical services in sub-Saharan Africa, through the Hilton Cataract Initiative.

  20. Cataract: A major secondary complication of diabetes, its epidemiology and an overview on major medicinal plants screened for anticataract activity

    Directory of Open Access Journals (Sweden)

    Patel DK

    2011-12-01

    Full Text Available Cataract is a visual impairment caused due to opacification or optical dysfunction of crystallin lens affecting more than 17 million people around the world. Even though the incidences of cataract are increasing day by day among the elderly persons but, still except surgery no other ways of treatment have been successfully developed so far. Thus, the aim of writing the present review is to provide an insight over the pathophysiological and etiological aspects of cataract along with discussing the remedies available for the disorder. The review also describes different experimental models with their relevant mechanism and significance such as galactose-induced, naphthalene-induced and selenite-induced cataract models which are mainly used for evaluating the anticataract activity of a particular drug (mainly of natural origin. The review includes list of plants and their phytoconstituents which have been so far evaluated pharmacologicaly for the treatment of cataract. From the survey, it was confirmed that the antioxidant property of plants phytoconstituents are basically responsible for their effective anticataract activity. Thus, the valuable information provided in the present review will help researches in developing an alternative method rather than surgery for the treatment of cataract which will minimize the rate of blindness due to cataract thus, benefiting and extending protective aspects of eyes, an integral part of human body.

  1. Occupational exposure to low doses of ionizing radiation and cataract development: a systematic literature review and perspectives on future studies

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    Hammer, Gael P. [University Medical Center of the Johannes Gutenberg University Mainz, Institute for Medical Biostatistics, Epidemiology and Informatics (IMBEI), Mainz (Germany); Registre Morphologique des Tumeurs, Laboratoire National de Sante, Luxembourg (Luxembourg); Scheidemann-Wesp, Ulrike; Wicke, Henryk; Blettner, Maria [University Medical Center of the Johannes Gutenberg University Mainz, Institute for Medical Biostatistics, Epidemiology and Informatics (IMBEI), Mainz (Germany); Samkange-Zeeb, Florence [University Medical Center of the Johannes Gutenberg University Mainz, Institute for Medical Biostatistics, Epidemiology and Informatics (IMBEI), Mainz (Germany); Leibniz Institute for Prevention Research and Epidemiology - BIPS GmbH, Department of Prevention and Evaluation, Bremen (Germany); Neriishi, Kazuo [Radiation Effects Research Foundation, Hiroshima (Japan)

    2013-08-15

    Ionizing radiation is a well-known but little understood risk factor for lens opacities. Until recently, cataract development was considered to be a deterministic effect occurring at lens doses exceeding a threshold of 5-8 Gy. Substantial uncertainty about the level and the existence of a threshold subsists. The International Commission on Radiation Protection recently revised it to 0.5 Gy. Based on a systematic literature review of epidemiological studies on exposure to low levels of ionizing radiation and the occurrence of lens opacities, a list of criteria for new epidemiological studies was compiled, and a list of potential study populations was reviewed. Among 24 publications finally identified, six report analyses of acute exposures in atomic bomb survivors and Chernobyl liquidators, and the others report analyses of protracted exposures in occupationally, medically or accidentally exposed populations. Three studies investigated a dose threshold: in atomic bomb survivors, the best estimates were 1 Sv (95 % CI <0-0.8 Sv) regarding lensectomies; in survivors exposed as children, 0.6 Sv (90 % CI <0.0-1.2 Sv) for cortical cataract prevalence and 0.7 Sv (90 % CI 0.0-2.8 Sv) for posterior subcapsular cataract; and in Chernobyl liquidators, 0.34 Sv (95 % CI 0.19-0.68 Sv) for stage 1 cataract. Current studies are heterogeneous and inconclusive regarding the dose-response relationship. Protracted exposures and high lens doses occur in several occupational groups, for instance, in physicians performing fluoroscopy-guided interventional procedures, and in accidentally exposed populations. New studies with a good retrospective exposure assessment are feasible and should be initiated. (orig.)

  2. Risk of Cataract Incidence in a Cohort of Mayak PA Workers following Chronic Occupational Radiation Exposure.

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    Tamara V Azizova

    Full Text Available This is the first study of cataract incidence in a cohort of Mayak Production Association workers first employed at one of the main facilities in 1948-1982 and followed up till the end of 2008 (22,377 workers. Principal advantages of the study are the large size of the cohort, long-term follow-up and sufficient statistical power, available results of annual eye examinations over the entire follow-up period and detailed information on non-radiation confounders. Individual measured doses from external γ-rays and neutrons used in the analyses were provided by the Mayak Worker Dosimetry System 2008 (MWDS-2008. Relative risk (RR and excess relative risk (ERR per unit dose (Gy were calculated based on maximum likelihood using the AMFIT module of the EPICURE software. The RR of cataract incidence was found to be the highest in workers exposed at doses above 2.0 Gy. A significant linear association of cataract incidence with cumulative dose from external γ-rays was found with ERR/Gy equal to 0.28 (95% confidence intervals: 0.20, 0.37. The results obtained varied slightly with inclusion of additional adjustments for non-radiation factors (smoking index, hypertension, glaucoma and body mass index. Adjusting for the dose from neutrons gave a considerable increase in ERR/Gy for cataract incidence.

  3. Space Radiation and its Associated Health Consequences

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    Wu, Honglu

    2007-01-01

    During space travel, astronauts are exposed to energetic particles of a complex composition and energy distribution. For the same amount of absorbed dose, these particles can be much more effective than X- or gamma rays in the induction of biological effects, including cell inactivation, genetic mutations, cataracts, and cancer induction. Several of the biological consequences of space radiation exposure have already been observed in astronauts. This presentation will introduce the space radiation environment and discuss its associated health risks. Accurate assessment of the radiation risks and development of respective countermeasures are essential for the success of future exploration missions to the Moon and Mars.

  4. Different experimental approaches in modelling cataractogenesis: An overview of selenite-induced nuclear cataract in rats.

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    Kyselova, Zuzana

    2010-03-01

    Cataract, the opacification of eye lens, is the leading cause of blindness worldwide. At present, the only remedy is surgical removal of the cataractous lens and substitution with a lens made of synthetic polymers. However, besides significant costs of operation and possible complications, an artificial lens just does not have the overall optical qualities of a normal one. Hence it remains a significant public health problem, and biochemical solutions or pharmacological interventions that will maintain the transparency of the lens are highly required. Naturally, there is a persistent demand for suitable biological models. The ocular lens would appear to be an ideal organ for maintaining culture conditions because of lacking blood vessels and nerves. The lens in vivo obtains its nutrients and eliminates waste products via diffusion with the surrounding fluids. Lens opacification observed in vivo can be mimicked in vitro by addition of the cataractogenic agent sodium selenite (Na(2)SeO(3)) to the culture medium. Moreover, since an overdose of sodium selenite induces also cataract in young rats, it became an extremely rapid and convenient model of nuclear cataract in vivo. The main focus of this review will be on selenium (Se) and its salt sodium selenite, their toxicological characteristics and safety data in relevance of modelling cataractogenesis, either under in vivo or in vitro conditions. The studies revealing the mechanisms of lens opacification induced by selenite are highlighted, the representatives from screening for potential anti-cataract agents are listed.

  5. Outcomes and complications after phacoemulsification in retinoblastoma patients with cataract after radiation treatment.

    Science.gov (United States)

    Velásquez-Aguilar, M; Matiz-Moreno, H; Amato-Almanza, M; Chen-López, C Y; Márquez-García, G; Ramírez-Ortiz, M A

    2017-04-01

    To describe the visual outcome and complications associated with phacoemulsification in patients with bilateral retinoblastoma (Rb), with lens opacification secondary to external beam radiotherapy. A descriptive study was performed on patients with Rb, treated in Federico Gomez Children's Hospital, Mexico, from January 1997 to August 2015, with external beam radiotherapy eye salvaging. Statistical analysis was performed using Stata 10. A total of 15 patients were included. The mean age at phacoemulsification was 7.5 years. Mean preoperative visual acuity was 1.0LogMAR (range 0.4-1.6), and the mean postoperative visual acuity was 0.7LogMAR (range 0.1-1.6). Twelve patients had visual improvement (P<.05). The visual acuity decreased in one patient with vitreous haemorrhage and secondary glaucoma, and 2 patients with exudative maculopathy secondary to radiation. Mean follow up was 46 months and not a single patient showed tumour re-activation. Cataract surgery produces a statistically significant improvement in visual acuity. These patients have increased risk for eye complications in the mid- and long-term. It is important to conduct a close follow up due to reactivation of tumour. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Aniseikonia induced by cataract surgery and its effect on binocular vision.

    Science.gov (United States)

    Rutstein, Robert P; Fullard, Roderick J; Wilson, Jason A; Gordon, Adam

    2015-02-01

    This study measured aniseikonia before and after the first and second cataract surgeries in ametropic adults. The relationship of aniseikonia to anisometropia and its effect on stereopsis, ocular alignment, and clinical symptoms were determined. Seventeen patients scheduled to have bilateral cataract surgery with 2 diopters or more ametropia participated. Patients were evaluated before cataract surgery and 4 weeks (±1 week) after the first and second surgery. Visual acuity, refractive error, aniseikonia, stereopsis, ocular alignment, and visual symptoms were determined at each visit. Aniseikonia increased after the first cataract surgery. The increase in aniseikonia occurred in concert with increased anisometropia and resulted in poorer stereopsis overall. Aniseikonia and anisometropia 1 month (±1 week) after the second cataract surgery returned to near baseline and were associated with better stereopsis. The amount of aniseikonia showed substantial variance and could not be predicted by the amount of induced anisometropia. Changes in ocular alignment were minimal. Statistically significant changes in patient symptoms between study visits were infrequent. Aniseikonia induced by cataract surgery may not be a substantial problem for ametropic adults with normal binocular vision, at least in the short term.

  7. [Cataract surgery and its impact on balance and autonomy in elderly].

    Science.gov (United States)

    Raynal, M; Aupy, B; Jahidi, A; Ettien, D; Le Page, P; Briche, T; Kossowski, M; Pailllaud, E

    2009-01-01

    Cataract is a major cause of visual impairment among elderly. Cataract surgery improves visual afferencies and can have an impact on balance. The present study assessed the impact of cataract surgery upon balance and autonomy in elderly. We realized clinical examinations and objective tests the day before surgery and 2-months later. The initial cohort consisted of 66 patients that had to undergo a cataract surgery. Their mean age was 79 +/- 0.5. For logistic reasons, only 33 patients have been completely evaluated before and after surgery. Each patient underwent a history and examination that have assessed autonomy, walking, visual and then cochleo-vestibular functions including bone vibratory test and dynamic computerized posturography (Equitest). After 2 months, cataract surgery had no incidence on balance. The fear of falling has stayed the same whereas the number of falls has been noticeably reduced by surgery. The overall score of Equitest has shown an increase in visual dependence after surgery. Although cataract surgery has no incidence on autonomy, it may improve the quality of life among older people by leisure activities recovery. An early physical rehabilitation facilitated by visual improvement after surgery can also prevent visual dependence and autonomy loss. We recommend vestibular rehabilitation in elderly with major visual dependence.

  8. Atm heterozygous mice are more sensitive to radiation-induced cataracts than are their wild-type counterparts

    Science.gov (United States)

    Worgul, Basil V.; Smilenov, Lubomir; Brenner, David J.; Junk, Anna; Zhou, Wei; Hall, Eric J.

    2002-01-01

    It is important to know whether the human population includes genetically predisposed radiosensitive subsets. In vitro studies have shown that cells from individuals homozygous for ataxia telangiectasia (A-T) are much more radiosensitive than cells from unaffected individuals. Although cells heterozygous for the ATM gene (ATM(+/-)) may be slightly more radiosensitive in vitro, it remained to be determined whether the greater susceptibility of ATM(+/-) cells translates into an increased sensitivity for late effects in vivo, though there is a suggestion that radiotherapy patients that are heterozygous for the ATM gene may be more at risk of developing late normal tissue damage. We chose cataractogenesis in the lens as a means to assay for the effects of ATM deficiency in a late-responding tissue. One eye of wild-type, Atm heterozygous and homozygous knockout mice was exposed to 0.5-, 1.0-, 2.0-, or 4.0-Gy x rays. The animals were followed weekly for cataract development by conventional slit-lamp biomicroscopy. Cataract development in the animals of all three groups was strongly dependent on dose. The lenses of homozygous mice were the first to opacify at any given dose. Most important in the present context is that cataracts appeared earlier in the heterozygous versus wild-type animals. The data suggest that ATM heterozygotes in the human population may also be radiosensitive. This may influence the choice of individuals destined to be exposed to higher than normal doses of radiation, such as astronauts, and may also suggest that radiotherapy patients who are ATM heterozygotes could be predisposed to increased late normal tissue damage.

  9. Effect of Geranylgeranylacetone on Ultraviolet Radiation Type B-Induced Cataract in Heat-Shock Transcription Factor 1 Heterozygous Mouse.

    Science.gov (United States)

    Ogasawara, Satoshi; Hashizume, Kouhei; Okuno, Takashi; Imaizumi, Toshiyasu; Inomata, Yui; Tezuka, Yu; Sanbe, Atushi; Kurosaka, Daijiro

    2017-05-01

    We investigated whether heat-shock transcription factor 1 (HSF1) was involved in ultraviolet radiation type B (UVR-B)-induced lens opacity (cataract) using HSF1 heterozygous mice. We also examined the effects of geranylgeranylacetone (GGA), an inducer of heat-shock proteins via activation of HSF, on the UVR-B-induced cataract. Male HSF1+/- and WT mice were unilaterally exposed to UVR-B (total: 1200mJ) at 16 weeks of age. At 48 h after the last UVR-B irradiation, the lens was isolated and the induction of the cataract was quantified as the cataract area ratio (opacity area/anterior capsule). GGA was orally administered at a dosage of 500 mg/kg once a day for two days before the first UVR-B exposure until the end of the experiment (21days in total). The HSF1 expression was more greatly decreased in the lens from HSF1+/- mice than in that from WT mice (p cataracts in the anterior capsule in both HSF1+/- and WT mice, while the opacity of the lens was markedly enhanced in HSF1+/- mice compared to that in WT mice(p (0.01). GGA treatment could prevent the induction of lens opacity by UVR-B exposure in both WT and HSF1+/- mice as compared with the non-administration group (p cataracts, possibly via regulation of HSPs such as HSP25.

  10. Cosmic radiation increases the risk of nuclear cataract in airline pilots: a population-based case-control study.

    Science.gov (United States)

    Rafnsson, Vilhjalmur; Olafsdottir, Eydis; Hrafnkelsson, Jon; Sasaki, Hiroshi; Arnarsson, Arsaell; Jonasson, Fridbert

    2005-08-01

    Aviation involves exposure to ionizing radiation of cosmic origin. The association between lesions of the ocular lens and ionizing radiation is well-known. To investigate whether employment as a commercial airline pilot and the resulting exposure to cosmic radiation is associated with lens opacification. This is a population-based case-control study of 445 men. Lens opacification was classified into 4 types using the World Health Organization simplified grading system. These 4 types, serving as cases, included 71 persons with nuclear cataracts, 102 with cortical lens opacification, 69 with central optical zone involvement, and 32 with posterior subcapsular lens opacification. Control subjects are those with a different type of lens opacification or without lens opacification. Exposure was assessed based on employment time as pilots, annual number of hours flown on each aircraft type, time tables, flight profiles, and individual cumulative radiation doses (in millisieverts) calculated by a software program. Odds ratios were calculated using logistic regression. The odds ratio for nuclear cataract risk among cases and controls was 3.02 (95% confidence interval, 1.44-6.35) for pilots compared with nonpilots, adjusted for age, smoking status, and sunbathing habits. The odds ratio for nuclear cataract associated with estimation of cumulative radiation dose (in millisieverts) to the age of 40 years was 1.06 (95% confidence interval, 1.02-1.10), adjusted for age, smoking status, and sunbathing habits. The association between the cosmic radiation exposure of pilots and the risk of nuclear cataracts, adjusted for age, smoking status, and sunbathing habits, indicates that cosmic radiation may be a causative factor in nuclear cataracts among commercial airline pilots.

  11. Protective effects of Cassia tora leaves in experimental cataract by modulating intracellular communication, membrane co-transporters, energy metabolism and the ubiquitin-proteasome pathway.

    Science.gov (United States)

    Sreelakshmi, V; Abraham, Annie

    2017-12-01

    Cataract is the clouding of eye lens which causes impairment in vision and accounts for the leading factor of global blindness. Functional food-based prevention of cataract finds application in vision research because of its availability and easy access to all classes of the society. Cassia tora Linn. (Caesalpinaceae) is an edible plant mentioned in the traditional systems of medicine for whole body health, especially to the eyes. The present study evaluates the potential of ethyl acetate fraction of Cassia tora leaves (ECT) on experimental cataract. Cataract was induced by a single subcutaneous injection of sodium selenite (4 μg/g body weight) on 10th day. ECT was supplemented orally from 8th day up to 12th day at a concentration of 5 μg/g body weight and marker parameters were evaluated after 30 days. The production of MPO and the activation of calpain were reduced 52.17% and 36.67% by ECT in lens tissue, respectively. It modulated the energy status by significantly increasing the activity of CCO 1 (55.56%) and ATP production (41.88%). ECT maintained the ionic balance in the lens by reducing the level of sodium (50%) and increasing the level of potassium (42.5%). It also reduced cell junction modifications and preserved a functional ubiquitin-proteasome pathway. The results reinforce the growing attention on wild plant food resources for preventive protection against cataract. The data suggest the value of Cassia tora leaves as a functional food for ameliorating cataract pathology.

  12. Association of Radiation Dose to the Eyes With the Risk for Cataract After Nonretinoblastoma Solid Cancers in Childhood.

    Science.gov (United States)

    Allodji, Rodrigue S; Diallo, Ibrahima; El-Fayech, Chiraz; Kahlouche, Amar; Dumas, Agnès; Schwartz, Boris; Oberlin, Odile; Benadjaoud, Mohamed Amine; Labbé, Martine; Jackson, Angela; Bullet, Julien; Rubino, Carole; Haddy, Nadia; De Vathaire, Florent

    2016-04-01

    Few studies have been published on the association of the radiation dose received to the eyes during radiotherapy (RT) for childhood cancer and the risk for later cataract. To investigate the risk for cataract after treatment of nonretinoblastoma solid cancer in childhood. The study used data from the Euro2K cohort that includes 4389 5-year survivors of solid tumors treated from January 1, 1945, to December 31, 1985; of these, 3172 patients were treated in France. A self-reported questionnaire was sent to French survivors from September 1, 2005, to December 31, 2012, when follow-up was considered completed for this study. However, 619 patients died before the beginning of the study and 128 patients treated for a retinoblastoma or who underwent enucleation were excluded. Likewise, 429 patients with unknown addresses or who did not return the consent form and 163 nonresponders did not participate. The remaining 1833 patients who completed the questionnaire underwent analysis for this study from June 1, 2014, to December 7, 2015. Radiation doses in both eyes for individuals were estimated for all patients who had received RT. The role of the radiation dose in cataract risk was investigated using the Cox proportional hazard regression model and the excess relative or the absolute risk model. The role of ctytotoxic chemotherapy was also investigated. The 1833 patients (961 men [52.4%]; 872 women [47.6%]; mean [SD] age, 37.0 [8.5]) who returned the questionnaire were included in the analysis. After a mean follow-up of 32 years, 33 patients with unilateral or bilateral cataract were identified, for a total of 47 cataract events. The 47 events were validated by medical record review and by contacting the patients and the corresponding medical physician or ophthalmologist to obtain copies of diagnostic examinations or surgical reports. Overall, in a multivariable Cox proportional hazard regression analysis, patients who received RT had a 4.4-fold (95% CI, 1.5- to 13.0-fold

  13. Model of risk of cortical cataract in the US population with exposure to increased ultraviolet radiation due to stratospheric ozone depletion.

    Science.gov (United States)

    West, Sheila K; Longstreth, Janice D; Munoz, Beatriz E; Pitcher, Hugh M; Duncan, Donald D

    2005-12-01

    The authors modeled the possible consequences for US cataract incidence of increases in ultraviolet B radiation due to ozone depletion. Data on the dose-response relation between ocular exposure to ultraviolet B radiation and cortical cataract were derived from a population-based study (the Salisbury Eye Evaluation Project, Salisbury, Maryland) in which extensive data on cataract and ultraviolet radiation were collected in persons aged 65-84 years. Exposure estimates for the US population were derived using estimated ultraviolet radiation fluxes as a function of wavelength. US Census data were used to obtain the age, ethnicity, and sex distribution of the population. Predicted probabilities of cataract were derived from the age-, sex-, and ethnicity-specific ocular ultraviolet exposure data and were modeled under conditions of 5-20% ozone depletion. The analysis indicated that by 2050, the prevalence of cortical cataract will increase above expected levels by 1.3-6.9%. The authors estimate that with 5-20% ozone depletion, there will be 167,000-830,000 additional cases of cortical cataract by 2050. Because of the high prevalence of cataract in older persons, at a 2003 cost of 3,370 dollars per cataract operation, this increase could represent an excess cost of 563 million dollars to 2.8 billion dollars.

  14. Cataract (image)

    Science.gov (United States)

    A cataract is a cloudy or opaque area in the lens of the eye. Cataracts usually develop as a person gets older and ... substances can also accelerate the development of a cataract. Cataracts can cause visual problems such as difficulty ...

  15. Radiation-induced cataracts. Glance at some new data; Les catarates radio-induites. Regard sur de nouvelles donnees

    Energy Technology Data Exchange (ETDEWEB)

    Wassilieff, S. [Ecole des Applications Militaires de l' Energie Atomique, 50 - Cherbourg-Octeville (France)

    2009-10-15

    The radiation-induced cataract has been up to now considered as a quite rare pathology, needing high-dose radiations (beyond a dose threshold roughly estimated at 2 Grays to the lens) consisting mainly in head tumour radiotherapy complications. Several new studies on different exposed populations such as astronauts, Japanese atomic bomb survivors, people undergoing X-ray examinations, Chernobyl accident 'liquidators' as well as data from animal experiments, suggest that dose threshold for detectable opacities as well as for clinical posterior sub-capsular cataract occurring, might be far lower than those previously assumed. Even the existence of a dose threshold is no longer an absolute certitude insofar as radiation-induced cataract pathogenesis might consist not really in a deterministic effect (direct tissue harmful effect, killing or seriously injuring a critical population of cells) as believed until now, but rather in a stochastic effect (genomic damage in target-cells, altered cell division, abnormal lens fibre cell differentiation). More practically, these new data may lead us to reconsider radioprotection of specifically exposed populations : mainly patients and workers. Regarding workers, labour legislation (lens equivalent dose limit of 150 mSv during 12 consecutive months) might be, in the medium term, reassessed downwards. (author)

  16. Eye lens dosimetry and the study on radiation cataract in interventional cardiologists.

    Science.gov (United States)

    Matsubara, Kosuke; Lertsuwunseri, Vorarit; Srimahachota, Suphot; Krisanachinda, Anchali; Tulvatana, Wasee; Khambhiphant, Bharkbhum; Sudchai, Waraporn; Rehani, Madan

    2017-12-01

    To determine the eye lens dose of the Interventional Cardiology (IC) personnel using optically stimulated luminescent dosimeter (OSLD) and the prevalence and risk of radiation - associated lens opacities in Thailand. 48 IC staff, with age- and sex- matches 37 unexposed controls obtained eye examines. Posterior lens change was graded using a modified Merriam-Focht technique by two independent ophthalmologists. Occupational exposure (mSv) was measured in 42 IC staff, using 2 OSLD badges place at inside lead apron and at collar. Annual eye lens doses (mSv) were also measured using 4 nanoDots OSL placed outside and inside lead glass eyewear. The prevalence of radiation-associated posterior lens opacities was 28.6% (2/7) for IC, 19.5% (8/41) for nurses, and 2.7% (1/37) for controls. The average and range of annual whole body effective dose, Hp(10), equivalent dose at skin of the neck, Hp(0.07) and equivalent dose at eye lens, Hp(3) were 0.80 (0.05-6.79), 5.88 (0.14-35.28), and 5.73 (0.14-33.20) mSv respectively. The annual average and range of eye lens dose using nano Dots OSL showed the outside lead glass eyewear on left and right sides as 8.06 (0.17-32.45), 3.55(0.06-8.04) mSv and inside left and right sides as 3.91(0.05-14.26) and 2.44(0.06-6.24) mSv respectively. Eye lens doses measured by OSLD badges and nano Dot dosimeter as Hp(10), Hp(0.07) and Hp(3). The eyes of the IC personnel were examined annually by two ophthalmologists for the prevalence of cataract induced by radiation. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  17. Targeting CYP450 modulation to decrease the risk of induced cataract in the experimental model

    Directory of Open Access Journals (Sweden)

    Patel D

    2010-01-01

    Full Text Available Background: Diabetes is one of the major causes of cataract. Some drugs prescribed for the treatment of diabetes are the modulators of CYP450, which may alter the risk of cataract. Objective: To study the effect of CYP450 modulation in galactosemic cataract. Materials and Methods: Male Sprague-Dawley suckling rats were allotted to four groups (n = 6, as follows: Group 1: Normal control, Group 2: Galactose control, Group 3: CYP450 inhibitor pretreated and Group 4: CYP450 inducer pretreated. Cataract was induced in animals of all groups except group 1 by feeding them galactose (50%, 21 days after parturition. From the eighteenth day of life, CYP450 inhibitor (nifedipine; 8.1 mg/kg and CYP450 inducer (pioglitazone; 3.8 mg/kg were given orally to groups 3 and 4, respectively. The maturation pattern of the cataract was observed by an operating microscope, every third day. Biochemical changes in the lenses of all groups, for example, CYP450 activity expressed as ΅M NADPH oxidized / unit time, alterations in the levels of total proteins, soluble proteins, and reduced glutathione (GSH following the induction of cataract, were estimated. Results: The microscopic examination of the lenses indicated that CYP450 inhibitor pre-treatment delayed (fourteenth day the occurrence of cataract, while CYP450 inducer pretreatment demonstrated an early (ninth day cataract as compared to galactose control rats (twelfth day. A significant decrease and increase in CYP450 activity was observed with the CYP450 inhibitor and inducer pre-treatment, respectively. There was no alteration in the GSH level, but a significant increase in total and soluble protein was found in groups 3 and 4 as compared to group 2. Conclusion: CYP450 may have a role in the initiation of cataract without any effect on the maturation pattern, as revealed by the delayed occurrence of cataract with the CYP450 inhibitor and an early onset of cataract with the CYP450 inducer.

  18. Comparison of the impact of epigallocatechin gallate and ellagic acid in an experimental cataract model induced by sodium selenite

    Directory of Open Access Journals (Sweden)

    Irfan Ergen

    2017-04-01

    Full Text Available "AIM: To compare the potential protective effects of epi-gallocatechin gallate (EGCG and ellagic acid (EA in an experimental cataract model. METHODS: Twenty-eight Spraque-Dawley rat pups were assigned into four groups. All the rats, except for those in the control group, were injected subcutaneously sodium selenite to induce experimental cataract on the postpartum ninth day, and between 10th and 14th days. Rats in the sham, EGCG, and EA groups were intraperitoneally administered 50 mg/(kg·d saline solution, 50 mg/(kg·d EGCG and 200 mg/(kg·d EA, respectively. The reduced glutathione (GSH and malondialdehyde (MDA levels, total antioxidant status (TAS and total oxidant status (TOS in lens supernatants were measured. RESULTS: The mean cataract gradings in EGCG and EA groups were found to be significantly lower than that in sham group (P<0.001. The mean GSH levels and TASs in EGCG and EA groups were significantly higher than that in sham group while mean MDA levels and TOSs in EGCG and EA groups were significantly lower than that in the sham group (P<0.001. CONCLUSION: EGCG and EA have protective effects on cataract development via the inhibition of oxidative stress."

  19. Potential pre-cataractous markers induced by low-dose radiation effects in cultured human lens cells

    Science.gov (United States)

    Blakely, E.; McNamara, M.; Bjornstad, K.; Chang, P.

    The human lens is one of the most radiosensitive organs of the body. Cataract, the opacification of the lens, is a late-appearing response to radiation damage. Recent evidence indicates that exposure to relatively low doses of space radiation are associated with an increased incidence and early appearance of human cataracts (Cucinotta et al., Radiat. Res. 156:460-466, 2001). Basic research in this area is needed to integrate the early responses of various late-responding tissues into our understanding and estimation of radiation risk for space travel. In addition, these studies may contribute to the development of countermeasures for the early lenticular changes, in order to prevent the late sequelae. Radiation damage to the lens is not life threatening but, if severe, can affect vision unless surgically corrected with synthetic lens replacement. The lens, however, may be a sensitive detector of radiation effects for other cells of ectodermal origin in the body for which there are not currently clear endpoints of low-dose radiation effects. We have investigated the dose-dependent expression of several radiation-responsive endpoints using our in vitro model of differentiating human lens epithelial cells (Blakely et al., Investigative Ophthalmology &Visual Sciences, 41(12):3898-3907, 2000). We have investigated radiation effects on several gene families that include, or relate to, DNA damage, cytokines, cell-cycle regulators, cell adhesion molecules, cell cytoskeletal function and apoptotic cell death. In this paper we will summarize some of our dose-dependent data from several radiation types, and describe the model of molecular and cellular events that we believe may be associated with precataractous events in the human lens after radiation exposure. This work was supported by NASA Grant #T-965W.

  20. Environmental dose rate heterogeneity of beta radiation and its implications for luminescence dating: Monte Carlo modelling and experimental validation

    DEFF Research Database (Denmark)

    Nathan, R.P.; Thomas, P.J.; Jain, M.

    2003-01-01

    The recent development of rapid single sand-sized grain analyses in luminescence dating has necessitated the accurate interpretation of D-e distributions to recover a representative D-e acquired since the last bleaching event. Beta heterogeneity may adversely affect the variance and symmetry of D...... and identify the likely size of these effects on D-e distributions. The study employs the MCNP 4C Monte Carlo electron/photon transport model, supported by an experimental validation of the code in several case studies. We find good agreement between the experimental measurements and the Monte Carlo......-e distributions and it is important to characterise this effect, both to ensure that dose distributions are not misinterpreted, and that an accurate beta dose rate is employed in dating calculations. In this study, we make a first attempt providing a description of potential problems in heterogeneous environments...

  1. EXPOSURE TO RADIATION WELDING WORKERS IN PT.PUTRA SULTRA SAMUDERA KENDARI AGAINST DISEASE DISORDERS CATARACT

    Directory of Open Access Journals (Sweden)

    Abdul Rahim Sya’ban

    2015-12-01

    Full Text Available Background: In the industrial sector, the number of workers employed quite a lot, with the type and intensity of the various aspects of the environment including physical, chemical, biological and psychosocial. Various kinds of environments can cause a variety of occupational diseases. Aim: To determine the relationship between distance and time exposure PT. Putra Sultra Samudera Kendari against cataracts Methods: This research was a survey research with cross sectional analytic study, the data collection were accomplsihed in a certain time to describe the condition of the population Results: The results showed a strong relationship between the suitability of distance, time of exposure to diseases cataracts Conclusions: There was a positive correlation and significant influence between the suitability of the distance and time of exposure with cataract disorder, the use of Personal Protective Equipment showed a positive relationship and did not have a significant effect on cataract disorders in workers in the welding parts firm PT. Putra Sultra Samudera Kendari.

  2. 1090 nm infrared radiation at close to threshold dose induces cataract with a time delay.

    Science.gov (United States)

    Yu, Zhaohua; Schulmeister, Karl; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per G

    2015-03-01

    To investigate whether infrared radiation (IRR)-induced cataract is instant or is associated with a time delay between the exposure and the onset of lens light scattering after an exposure to just above threshold dose. Six-weeks-old albino Sprague-Dawley female rats were unilaterally exposed to 197 W/cm2 IRR at 1090 nm within the dilated pupil. In the first experiment, the animals were exposed with four exposure times of 5, 8, 13 and 20 second, respectively. At 24 hr after exposure, the light scattering in both exposed and contralateral not exposed lenses was measured. Based on the first experiment, four postexposure time groups were exposed unilaterally to 1090 nm IRR of 197 W/cm2 for 8 second. At 6, 18, 55 and 168 hr after exposure, the light scattering in both lenses was measured. A 197 W/cm2 IRR-induced light scattering in the lens with exposures of at least 8 second. Further, after exposure to IRR of 197 W/cm2 for 8 second, the light-scattering increase in the lens was delayed approximately 16 hr after the exposure. There is a time delay between the exposure and the onset of cataract after exposure to close to threshold dose implicating that either near IRR cataract is photochemical or there is a time delay in the biological expression of thermally induced damage. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  3. NASA study of cataract in astronauts (NASCA). Report 1: Cross-sectional study of the relationship of exposure to space radiation and risk of lens opacity.

    Science.gov (United States)

    Chylack, Leo T; Peterson, Leif E; Feiveson, Alan H; Wear, Mary L; Manuel, F Keith; Tung, William H; Hardy, Dale S; Marak, Lisa J; Cucinotta, Francis A

    2009-07-01

    The NASA Study of Cataract in Astronauts (NASCA) is a 5-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear, cortical and posterior subcapsular (PSC) lens opacities. Here we report on baseline data that will be used over the course of the longitudinal study. Participants include 171 consenting astronauts who flew at least one mission in space and a comparison group made up of three components: (a) 53 astronauts who had not flown in space, (b) 95 military aircrew personnel, and (c) 99 non-aircrew ground-based comparison subjects. Continuous measures of nuclear, cortical and PSC lens opacities were derived from Nidek EAS 1000 digitized images. Age, demographics, general health, nutritional intake and solar ocular exposure were measured at baseline. Astronauts who flew at least one mission were matched to comparison subjects using propensity scores based on demographic characteristics and medical history stratified by gender and smoking (ever/never). The cross-sectional data for matched subjects were analyzed by fitting customized non-normal regression models to examine the effect of space radiation on each measure of opacity. The variability and median of cortical cataracts were significantly higher for exposed astronauts than for nonexposed astronauts and comparison subjects with similar ages (P=0.015). Galactic cosmic space radiation (GCR) may be linked to increased PSC area (P=0.056) and the number of PSC centers (P=0.095). Within the astronaut group, PSC size was greater in subjects with higher space radiation doses (P=0.016). No association was found between space radiation and nuclear cataracts. Cross-sectional data analysis revealed a small deleterious effect of space radiation for cortical cataracts and possibly for PSC cataracts. These results suggest increased cataract risks at smaller radiation doses than have been reported previously.

  4. Model for the analysis of sun radiation structures exposed to open air: consideration of its validity and usefulness based on its experimentation in situ

    Science.gov (United States)

    Bottoni, Mario; Fabretti, Giuseppe

    2001-03-01

    The definition of the thermal dynamics of a structure-work of cultural interest is important both from the microclimatic point of view and from the structural one. Elastic and plastic deformations, due to phenomena of heat exchange, influence, in a significant way, the mechanical behavior of the structure. Dealing with objects exposed to open air, one of the main sources of heat radiation is, obviously, the sun. Consequently, it is significant to evaluate the importance that solar radiation has in the global heating dynamics of the structure. Therefore, while studying the system Marcus Aurelius- Capitolium square, it was decided to support the investigations in situ (carried out by using thermovision and thermocouples) with the realization, on computer, of a system that could define the theoretical relationship existing between solar dynamics and the bronze monument. Correlation between information deduced from such a model and data obtained in situ, gave useful results and constituted a significant instrument for the analysis of the concrete thermal model of the investigated structure. The opportunity to deepen and improve such an experience arose when the Soprintendenza per i Beni Architettonici ed Ambientali di Firenze e Pistoia asked for a contribution to the studies and investigations aimed to define the thermal model of the Dome of Santa Maria del Fiore.

  5. [Cataract surgery rate and its impacting factors in Jiangsu Province in 2012].

    Science.gov (United States)

    Guan, Huai-jin; Zhang, Xiao-jun; Zhu, Rong-rong; Yang, Mei

    2013-12-17

    To survey the cataract surgery rate (CSR) according to the report data and its influencing factors of Jiangsu Province in 2012 so as to further improve CSR in China. Through government websites in 2012, gross domestic product (GDP) and GDP per capital of 13 cities in Jiangsu Province and 7 counties of Nantong City reported to the Ministry of Health in China were collected to calculate CSR. The relationship between GDP and CSR of Jiangsu Province and Nantong City were analyzed with Spearman's rank correlation, and the differences in the proportion of cataract surgery between government and private hospitals were analyzed by Chi-square test. CSR in Jiangsu Province in 2012 was 939 cases per million population per year. Nantong City had the highest CSR (1362 cases per million population per year) and Suqian City the lowest (129 cases per million population per year). The GDP of 13 cities in Jiangsu Province had a positive correlation with CSR (spearman r = 0.59, P = 0.03), but there was no significant correlation with GDP per capital (spearman r = 0.50, P = 0.08). No significant correlation existed between GDP, GDP per capital and CSR of 7 counties of Nantong City (spearman r = -0.04, P = 0.94; spearman r = -0.29, P = 0.53). The proportion of private hospitals of Nantong was 33.3% and surgery cases were 4557 (45.9%). The CSR of Rugao County in 2012 was 3317 cases per million population per year. Socioeconomic level may be related with CSR. Providing village cataract screening services and lowering surgical costs help to boost CSR in China.

  6. A review of ground-based heavy ion radiobiology relevant to space radiation risk assessment: Cataracts and CNS effects

    Science.gov (United States)

    Blakely, Eleanor A.; Chang, Polly Y.

    Analysis of the numerous potential risks of travel into deep space is critical to future manned missions. Despite the availability of significant new information on heavy-ion radiobiology at high doses and high dose-rates, radiation effects on human physiology during space travel, and later in the career of the space traveler, remain high on the list of what still needs to be known under space radiation scenarios. Cancer risks have long been considered the most serious late effect from chronic daily relatively low-dose exposures to the complex space radiation environment. However, other late radiation effects from space radiation scenarios are under study in ground-based accelerator facilities and have revealed some unique particle radiation effects not observed with conventional radiations. A comprehensive review of pertinent literature that considers functional degradation of specific body organs and systems at risk has recently been published (NCRP Report #153, 2006). This paper highlights the review of two noncancer concerns from this report: cataracts and effects on the central nervous system.

  7. IOL Implants: Lens Replacement and Cataract Surgery (Intraocular Lenses)

    Science.gov (United States)

    ... Cataract Surgery vs. Laser-Assisted Cataract Surgery Cataract Vision Simulator Cataract Pictures and Videos: What Do ... Nov. 16, 2016 An intraocular lens (or IOL) is a tiny, artificial lens for the eye. It replaces the eye's ...

  8. Congenital cataract

    Science.gov (United States)

    ... both eyes. Moderate to severe cataracts that affect vision, or a cataract that is in only 1 eye, will need to be treated with cataract removal surgery. In most (noncongenital) cataract surgeries, an artificial intraocular lens (IOL) is inserted into the eye. ...

  9. Recurrence rate and radiation cataract of pterygium eye after postoperative /sup 90/Sr beta-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yasue, Hiroshi; Hori, Tomoko; Kinosita, Atsushi (Sakai Municipal Hospital, Osaka (Japan))

    1984-10-01

    The recurrence rate of pterygium was studied in 99 eyes that underwent /sup 90/Sr ..beta..-ray irradiation after surgery and in 12 eyes that did not. The follow-up period was 1 to 7 years. The recurrence rate was 2.9% in the 69 eyes which had undergone irradiation from the third day after operation, and 13.3% in the 30 eyes which had undergone irradiation from the seventh day or later after operation. The recurrence rate was 75% in the eyes which had undergone no irradiation. In 62 cases of postoperative irradiation in one eye, the presence of radiation cataract was investigated using the other eye as a control. The follow-up period was one to seven years. No radiation cataract was detected. Postoperative /sup 90/Sr ..beta..-ray irradiation is an effective and safe method of preventing recurrence of pterygium when applied from the third day after operation, one 1000 rad dose every week, 4 times consecutively.

  10. Reading performance depending on the type of cataract and its predictability on the visual outcome.

    Science.gov (United States)

    Stifter, Eva; Sacu, Stefan; Weghaupt, Herbert; König, Franz; Richter-Müksch, Sibylla; Thaler, Arnulf; Velikay-Parel, Michaela; Radner, Wolfgang

    2004-06-01

    To investigate the influence of various types of cataract on reading performance in a standardized reading test setting. Department of Ophthalmology, University of Vienna, Vienna, Austria. The reading performance of 94 eyes with age-related cataract and normal macular function was evaluated with the Radner Reading Charts preoperatively and 4 weeks after cataract surgery. Distance visual acuity was tested with the ETDRS charts. Cataracts were graded using the Lens Opacities Classification System (LOCS) III, on which NO is nuclear opalescence and NC is nuclear color. Patients with pure nuclear cataracts (LOCS III: NO/NC 2.1-5) achieved a normally high MRS (99.84% +/- 7.65% of their postoperative MRS): preoperative MRS(1): 190.6 +/- 30.74 words per minute (wpm); postoperative MRS(2): 191.21 +/- 29.36 wpm. Patients with mixed nuclear-cortical cataracts (LOCS III: NO/NC 2.1-5; C>2) preoperatively achieved 96.96% +/- 5.6% of their postoperative MRS (MRS(1): 175.77 +/- 31.54 wpm; MRS(2): 181.34 +/- 30.56 wpm). In dense nuclear cataracts (LOCS III: NO/NC>5), the MRS was significantly reduced, achieving only 72.64 +/- 19.19% of the postoperative MRS (MRS(1): 133.06 +/- 39.43 wpm; MRS(2): 185.76 +/- 40.18 wpm). In posterior subcapsular cataracts, the preoperative MRS (134.1 +/- 33.72 wpm) was significantly lower than postoperatively (191.14 +/- 27.08 wpm). In contrast to dense nuclear cataracts and posterior subcapsular cataracts, the preoperative reading speed of patients with pure nuclear or nuclear-cortical cataracts was normal at large print sizes. The preoperative evaluation of reading acuity and speed with standardized reading tests can therefore be used to estimate the postoperative reading performance in the latter 2 types of cataract.

  11. Phacolytic glaucoma-its treatment by planned extracapsular cataract extraction with posterior chamber intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Singh Gurdeep

    1994-01-01

    Full Text Available Phacolytic glaucoma has traditionally been treated with intracapsular lens extraction to avoid any anaphylaxis. Various mechanisms have been described for the rise of intraocular pressure in these cases. The present study was undertaken to evaluate the response of extracapsular cataract extraction (ECCE with posterior chamber intraocular lens implantation (PC IOL in five cases of phacolytic glaucoma that occurred between March 1989 and August 1990. A planned extracapsular cataract extraction with can-opener capsulectomy was done in all the cases with placement of a sulcus-fixated modified J-loop Sinskey design intraocular lens. With a mean follow-up period of two years, all patients (100% maintained a normal postoperative intraocular pressure of less than 20 mm Hg without any additional medical therapy. The final best-corrected visual acuity in 4 cases (80% was 6/12 or better, while in one case it was 6/24 due to a senile maculopathy. These results show that ECCE with PC IOL implantation is a safe and efficacious method of visual rehabilitation in cases of phacolytic glaucoma

  12. αA crystallin may protect against geographic atrophy-meta-analysis of cataract vs. cataract surgery for geographic atrophy and experimental studies.

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    Full Text Available BACKGROUND: Cataract and geographic atrophy (GA, also called advanced "dry" age-related macular degeneration are the two major causes of visual impairment in the developed world. The association between cataract surgery and the development of GA was controversial in previous studies. METHODS/PRINCIPAL FINDINGS: We performed a meta-analysis by pooling the current evidence in literature and found that cataract is associated with an increased risk of geographic atrophy with a summary odds ratio (OR of 3.75 (95% CI: 95% CI: 1.84-7.62. However, cataract surgery is not associated with the risk of geographic atrophy (polled OR=3.23, 95% CI: 0.63-16.47. Further experiments were performed to analyze how the αA-crystallin, the major component of the lens, influences the development of GA in a mouse model. We found that theαA-crystallin mRNA and protein expression increased after oxidative stress induced by NaIO(3 in immunohistochemistry of retinal section and western blot of posterior eyecups. Both functional and histopathological evidence confirmed that GA is more severe in αA-crystallin knockout mice compared to wild-type mice. CONCLUSIONS: Therefore, αA-crystallin may protect against geographic atrophy. This study provides a better understanding of the relationship between cataract, cataract surgery, and GA.

  13. Non-Invasive, Quantitative, and Remote Detection of Early Radiation Cataracts for Applications in Bio-Astronautics and Bio-Informatics

    Science.gov (United States)

    Ansari, Rafat R.; Giblin, Frank J.; King, James F.; Singh, B. (Technical Monitor)

    2002-01-01

    Human exploration of Mars may be a possibility in the next twenty years. Maintaining good vision is an essential aspect of achieving a successful mission. Continuous radiation exposure is a risk factor for radiation-induced cataracts in astronauts. A compact device based on the technique of dynamic light scattering (DLS) is designed for monitoring an astronaut's ocular health during long-duration space travel. Preliminary data on the simulated effects of ionizing radiation exposure to the ocular tissues of nonhuman animals and results on the sensitivity of DLS over established clinical procedures in investigating cataracts are presented. This capability of early diagnosis, unmatched by any other clinical technique in use today, may enable prompt initiation of preventive/curative therapy. An internet web based system integrating photon correlation data and controlling the hardware to monitor cataract development in vivo at a remote site in real time (teleophthalmology) is currently being developed. Cataract studies on-board the International Space Station (ISS) will be helpful in designing better protective radiation shields for future space vehicles and space suits.

  14. Radiation cataracts: mechanisms involved in their long delayed occurrence but then rapid progression.

    Science.gov (United States)

    Wolf, Norman; Pendergrass, William; Singh, Narendra; Swisshelm, Karen; Schwartz, Jeffrey

    2008-02-05

    This study was directed to assess the DNA damage and DNA repair response to X-ray inflicted lens oxidative damage and to investigate the subsequent changes in lens epithelial cell (LEC) behavior in vivo that led to long delayed but then rapidly developing cataracts. Two-month-old C57Bl/6 female mice received 11 Grays (Gy) of soft x-irradiation to the head only. The animals' eyes were examined for cataract status in 30 day intervals by slit lamp over an 11 month period post-irradiation. LEC migration, DNA fragment, free DNA retention, and reactive oxygen species (ROS) presence were established in the living lenses with fluorescent dyes using laser scanning confocal microscopy (LSCM). The extent and removal of initial LEC DNA damage were determined by comet assay. Immunohistochemistry was used to determine the presence of oxidized DNA and the response of a DNA repair protein in the lenses. This treatment resulted in advanced cortical cataracts that developed 5-11 months post-irradiation but then appeared suddenly within a 30 day period. The initially incurred DNA strand breaks were repaired within 30 min, but DNA damage remained as shown 72 h post-irradiation by the presence of the DNA adduct, 8-hydroxyguanosine (8-OHG), and a DNA repair protein, XRCC1. This was followed months later by abnormal behavior by LEC descendant cells with abnormal differentiation and migration patterns as seen with LSCM and fluorescent dyes. The sudden development of cortical cataracts several months post-irradiation coupled with the above findings suggests an accumulation of damaged descendants from the initially x-irradiated LECs. As these cells migrate abnormally and leave acellular lens surface sites, eventually a crisis point may arrive for lens entry of environmental O(2) with resultant ROS formation that overwhelms protection by resident antioxidant enzymes and results in the coagulation of lens proteins. The events seen in this study indicate the retention and transmission of

  15. Screening of Glaucoma or Cataract Prevalence in Vitiligo Patients and Its Relationship With Periorbital Steroid Use.

    Science.gov (United States)

    Khurrum, Huma; AlGhamdi, Khalid M; Osman, Essam

    2016-01-01

    There is scarce literature connecting vitiligo and primary open angle glaucoma (POAG). Most literature reports that secondary complications are a direct consequence of corticosteroid treatment of vitiligo. In this study, we aimed to investigate the prevalence of ocular problems in patients with vitiligo and to determine its association with periorbital topical corticosteroid use. A cross-sectional study was carried out on 90 patients with vitiligo. The Vitiligo European Task Force questionnaire was completed for each patient. A control group comprising 90 healthy individuals who did not have vitiligo and who were matched on age and gender was used for comparison. A complete ophthalmologic examination was performed. A family history of glaucoma and the use of topical steroids were recorded. Two (2/90, 2.2%) of the patients with vitiligo had glaucoma compared with none of the individuals in the control group (P = .25). Nineteen of the 90 patients with vitiligo used periorbital steroids, and of these patients, 10.5% (2/19) developed glaucoma. The duration of periorbital corticosteroid use was 4.50 ± 2.1 years. Eighty-nine percent (17/19) of the vitiligo patients who applied the potent topical corticosteroid (class I) clobetasol propionate to the periorbital area did not develop glaucoma. In contrast, glaucoma was not observed in 79% (71/90) of the vitiligo patients who did not use steroids. Cataract, uveitis, or fundus problems were not observed in either group. The study suggests that patients who have vitiligo and use topical steroids periorbitally do not have an increased risk of glaucoma or cataracts. Future studies that have a larger sample size and use a detailed steroid use protocol are needed. © The Author(s) 2015.

  16. Chemopreventive and remediation effect of Hydrocotyl bonariensis Comm. Ex Lam (Apiaceae) leave extract in galactose-induced cataract.

    Science.gov (United States)

    Ajani, E O; Salako, A A; Sharlie, P D; Akinleye, W A; Adeoye, A O; Salau, B A; Adebawo, O O

    2009-05-04

    Hydrocotyl bonariensis Comm. Ex Lam (Apiaceae) is being widely used in Western Nigeria in treating various symptoms of ophthalmic diseases; however scientific data in support of this medicinal use have not been reported. This study, investigated the efficacy of Hydrocotyl bonariensis leave extract in offering protection against experimental cataract and also examined its remediation effect when administered after cataract onset. Weanling albino rats fed with 30% galactose diet were used in the study. Mechanisms of action of the extract were investigated by measuring the degree of lens peroxidation, lens antioxidant status and lens protein concentration. Severity of cataract was determined by measuring the cataract index. The extract at 500 mg kg(-1) reduced cataract index significantly and also reduced cataract progression when administered after cataract onset. Administration of this dosage also significantly reduced the degree of lens peroxidation, increased the level of reduced glutathione (GSH) and the lens catalase and superoxide dismutase activity. The extract also prevents protein insolubilization. Administration of the extract at 1000 mg kg(-1) reduced cataract index and lens peroxidation but did not increase the antioxidant status significantly. Administration of the extract after cataract onset reduced cataract index, moderately increased percentage soluble protein above the value prior to the arrest of hypergalactosemia but did not increase the antioxidant status. Our study suggests that Hydrocotyl bonariensis protects against galactose-induced cataract, and that administration of the extract after cataract onset reduced cataract progression but did not reverse cataractogenesis.

  17. Improvements in Cataract Surgery

    NARCIS (Netherlands)

    Nibourg, Lisanne Maria

    2016-01-01

    Cataract is the leading cause of blindness and visual impairment in the elderly. It involves lens opacification due to biochemical changes in the lens. Cataract surgery provides restoration of good vision by removal of the opaque lens, followed by implantation of an intraocular lens (IOL) in the

  18. Dyschromatopsia following cataract surgery.

    Science.gov (United States)

    Jordan, D R; Valberg, J D

    1986-06-01

    The authors report on 19 individuals who experienced colour obscurations (dyschromatopsia) following cataract surgery. Although a transient blue discoloration (cyanopsia) might be expected following cataract surgery, an erythropsia (red vision) is more common. Symptoms generally begin after outdoor activity in bright sunlight, vary in duration and are recurrent. It is important to look for a history of drug use, migraine or cerebrovascular accidents.

  19. Cataract and Cataract Surgery: Nationwide Prevalence and Clinical Determinants.

    Science.gov (United States)

    Park, Sang Jun; Lee, Ju Hyun; Kang, Se Woong; Hyon, Joon Young; Park, Kyu Hyung

    2016-06-01

    This study aimed to investigate the prevalence and clinical determinants of cataract and cataract surgery in Korean population. The 2008-2012 Korean National Health and Nutrition Examination Survey was analyzed, which included 20,419 participants aged ≥ 40 years. The survey is a multistage, probability-cluster survey, which can produce nationally representative estimates. Prevalence of cataract and cataract surgery was estimated. Clinical determinants for those were investigated using logistic regression analyses (LRAs). The prevalence of cataract was 42.28% (95% confidence interval [CI], 40.67-43.89); 40.82% (95% CI, 38.97-42.66) for men and 43.62% (95% CI, 41.91-45.33) for women (P = 0.606). The prevalence of cataract surgery was 7.75% (95% CI, 7.30-8.20); 6.38% (95% CI, 5.80-6.96) for men and 9.01% (95% CI, 8.41-9.61) for women (P Cataract was associated with older age (P Cataract surgery was consistently associated with older age, occupation, DM, asthma, and anemia in two LRAs, which compared participants with cataract surgery to those without cataract surgery and those having a cataract but without any cataract surgery, respectively. Hypertension, arthritis, and dyslipidemia were associated with cataract surgery at least in one of these LRAs. These results suggest that there are 9.4 million individuals with cataract and 1.7 million individuals with cataract surgery in Korea. Further studies are warranted to reveal the causality and its possible mechanism of developing/exacerbating cataract in novel determinants (i.e., anemia, asthma, and arthritic conditions) as well as well-known determinants.

  20. Temperature-controlled in vivo ocular exposure to 1090-nm radiation suggests that near-infrared radiation cataract is thermally induced.

    Science.gov (United States)

    Yu, Zhaohua; Schulmeister, Karl; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per

    2015-01-01

    The damage mechanism for near-infrared radiation (IRR) induced cataract is unclear. Both a photochemical and a thermal mechanism were suggested. The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity. Groups of 20 rats were unilaterally exposed to 96-W/cm(2) IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, and 344 kJ/cm(2), respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was quantitatively measured. The average maximum temperature increases for exposure times of 10, 18, 33, and 60 min were expressed as 7.0 ± 1.1, 6.8 ± 1.1, 7.6 ± 1.3, and 7.4 ± 1.1 °C [CI (0.95)] at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not-exposed eyes was 0.00 ± 0.02, 0.01 ± 0.03, -0.01 ± 0.02, and -0.01 ± 0.03 transformed equivalent diazepam concentration (tEDC), respectively, and no apparent morphological changes in the lens were observed. An exposure to 96-W/cm(2) 1090-nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344 kJ/cm(2) does not induce cataract if the temperature rise at the limbus is thermal damage mechanism for IRR-induced cataract.

  1. Temperature-controlled in vivo ocular exposure to 1090-nm radiation suggests that near-infrared radiation cataract is thermally induced

    Science.gov (United States)

    Yu, Zhaohua; Schulmeister, Karl; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per

    2015-01-01

    The damage mechanism for near-infrared radiation (IRR) induced cataract is unclear. Both a photochemical and a thermal mechanism were suggested. The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity. Groups of 20 rats were unilaterally exposed to 96-W/cm2 IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, and 344 kJ/cm2, respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was quantitatively measured. The average maximum temperature increases for exposure times of 10, 18, 33, and 60 min were expressed as 7.0±1.1, 6.8±1.1, 7.6±1.3, and 7.4±1.1°C [CI (0.95)] at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not-exposed eyes was 0.00±0.02, 0.01±0.03, -0.01±0.02, and -0.01±0.03 transformed equivalent diazepam concentration (tEDC), respectively, and no apparent morphological changes in the lens were observed. An exposure to 96-W/cm2 1090-nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344 kJ/cm2 does not induce cataract if the temperature rise at the limbus is cataract.

  2. Radiation chemistry and its application

    Energy Technology Data Exchange (ETDEWEB)

    Majima, Tetsuro [Osaka Univ., Osaka (Japan)

    2013-07-01

    Effects of radiation to human body have been seriously discussed nowadays. These are important issues for the realization of sustainable society. It should be emphasized that various reactive intermediates generated by radiation play important roles in each cases. Radiation chemical studies will provide various reaction-mechanistic aspects on these important issues. Our research group has continuously carried out reaction-mechanistic studies using radiation chemical methods. From these studies, we have obtained a variety of results on basic molecular systems, reactions, materials that are close to practical application, biological systems and so on. Reactive species are generated from the radiation reactions in solution, and can be used as one-electron oxidative and reductive reagent to give selectively radical cation and anion of solute molecules such as various organic and inorganic molecules. Therefore, the radiation chemistry has contributed significantly to chemistry in which one-electron oxidation and reduction play the important role. The kinetics of such redox processes and the following reduction play the important role. The kinetics of such redox processes and the following reactions can be studied in real time with the transition absorption measurement by the pulse radiolysis technique. Even though the target compounds cannot be oxidized and reduced in chemical or electrochemical oxidation and reduction, their one-electron redox can be performed by the electron beam radiation. Therefore, radiation chemistry is very useful technique for basic science. Moreover, application potentials of radiation chemistry are so high for various research subjects. Moreover, application potentials of radiation chemistry are so high for various research subjects.

  3. Association between Cataract and Keratinocytic Skin Cancers or Melanoma: Speculating on the Common Role of Sun and Ultraviolet Radiation Exposures.

    Science.gov (United States)

    Varssano, David; Friedman, Mira; Goldstein, Michaella; Bar-Sela, Shai; Sella, Tal; Shalev, Varda; Chodick, Gabriel

    2017-10-01

    Cataract and sun-related skin conditions are proxies to lifetime UV exposure. We examined the association between them using real-world data from an unselected Israeli population. Computerized data was obtained from an Israeli health maintenance organization regarding cases of sun-related skin pathologies and cataract diagnosed between 2006 and 2011 in 686,260 members aged 40 or above. Sun-related skin disorders were found in 9.3% of the study population, more commonly among the elderly, and those who reside in areas of higher socioeconomic status. Cataract was diagnosed in 13.1% of the study population, with highest prevalence (47%) among squamous cell carcinoma patients, who were the oldest group. Multivariable analysis adjusting for age, sex, residential district, birth region, smoking, and chronic comorbidities showed no statistically significant association between melanoma and cataract (OR = 1.06; 95% CI: 0.91-1.22). Basal cell carcinoma, squamous cell carcinomas, and actinic keratosis were associated with increased likelihood of prevalent cataract with adjusted odds ratios (95% CI) of 1.14 (1.08-1.20), 1.11 (1.01-1.19), and 1.16 (1.13-1.19), respectively. When stratified by gender, the association between actinic keratosis and cataract was stronger in women than in men, particularly in patients under 65 years. The association between the prevalence of skin cancers and the prevalence of cataract enhances the conclusion that cataract is related to UVR exposure.

  4. Surgery for Congenital Cataract

    Directory of Open Access Journals (Sweden)

    David Yorston FRCS FRCOphth

    2004-01-01

    Full Text Available The management of congenital cataract is very different to the treatment of a routine age-related cataract. In adults, surgery may be delayed for years without affecting the visual outcome. In infants, if the cataract is not removed during the first year of life, the vision will never be fully regained after surgery. In adults, if the aphakia is not corrected immediately, it can be corrected later. In young children, if the aphakia is not corrected, the vision will never develop normally.

  5. Radiation-induced eye lens changes and risk for cataract in interventional cardiology.

    Science.gov (United States)

    Ciraj-Bjelac, O; Rehani, M; Minamoto, A; Sim, K H; Liew, H B; Vano, E

    2012-01-01

    Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings. To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology. The eyes of 52 staff in interventional cardiology facilities and 34 age- and sex-matched unexposed controls were screened in a cardiology conference held in Kuala Lumpur by dilated slit-lamp examination, and posterior lens changes were graded. Individual cumulative lens X-ray exposures were calculated from responses to a questionnaire in terms of workload and working practice. The prevalence of posterior lens opacities among interventional cardiologists was 53%, while in nurses and radiographers it was 45%. Corresponding relative risks were 2.6 (95% CI: 1.2-5.4) and 2.2 (95% CI: 0.98-4.9), for interventional cardiologists and support staff, respectively. This study confirms a statistically significant increase in radiation-associated posterior lens changes in the eyes of interventional cardiology staff. Copyright © 2012 S. Karger AG, Basel.

  6. Proposal for the experimental demonstration of the coherent radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, A.G.

    1992-08-01

    It is of great importance to provide an experimental demonstration of the coherence of the radiation of electromagnetic waves from a short bunch of electrons performing oscillations in a direction transverse to the main direction of motion. It is known that electrons circulating in a storage ring lose energy to synchrotron radiation. Another method to stimulate radiation is to let an electron bunch travel through a wiggler or an ondulator device. In either case the spectrum usually peaks in correspondence of wavelengths considerably smaller the length of the electron bunch in this situation the power radiated is then linearly proportional to the number N of electrons in the bunch, as it is customarily observed. Nevertheless, it may be possible conceiving a situation where the bunch length is considerably smaller or at least comparable to the wavelength of the peak of the radiation spectrum. If this is the case, it is then speculated that the power radiated is proportional to the square N{sup 2} of the number of particles in the bunch. This effect, which we can call a coherent effect, if of course very important since it would help to enhance the amount of the power radiated with a lower electron intensity. Unfortunately the coherent effect is difficult to observe since it is not easy to create beam and trajectory parameters which yield a bunch of length smaller than the radiation wavelength. We thus propose here an experiment which has the two goals: to generate an experimental situation where electrons in a bunch of length {ell} radiate electromagnetic power at a variable wavelength {lambda}, and to observe with measurements the total amount of radiation versus {lambda} and the beam intensity N. This experiment can be executed at the Accelerator Test Facility either at Brookhaven or at Argonne National Laboratory.

  7. Proposal for the experimental demonstration of the coherent radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, A.G.

    1992-01-01

    It is of great importance to provide an experimental demonstration of the coherence of the radiation of electromagnetic waves from a short bunch of electrons performing oscillations in a direction transverse to the main direction of motion. It is known that electrons circulating in a storage ring lose energy to synchrotron radiation. Another method to stimulate radiation is to let an electron bunch travel through a wiggler or an ondulator device. In either case the spectrum usually peaks in correspondence of wavelengths considerably smaller the length of the electron bunch in this situation the power radiated is then linearly proportional to the number N of electrons in the bunch, as it is customarily observed. Nevertheless, it may be possible conceiving a situation where the bunch length is considerably smaller or at least comparable to the wavelength of the peak of the radiation spectrum. If this is the case, it is then speculated that the power radiated is proportional to the square N{sup 2} of the number of particles in the bunch. This effect, which we can call a coherent effect, if of course very important since it would help to enhance the amount of the power radiated with a lower electron intensity. Unfortunately the coherent effect is difficult to observe since it is not easy to create beam and trajectory parameters which yield a bunch of length smaller than the radiation wavelength. We thus propose here an experiment which has the two goals: to generate an experimental situation where electrons in a bunch of length {ell} radiate electromagnetic power at a variable wavelength {lambda}, and to observe with measurements the total amount of radiation versus {lambda} and the beam intensity N. This experiment can be executed at the Accelerator Test Facility either at Brookhaven or at Argonne National Laboratory.

  8. Facts about Cataract

    Science.gov (United States)

    ... the cloudy lens and replacing it with an artificial lens. A cataract needs to be removed only when vision loss interferes with your everyday activities, such as driving, reading, or watching TV. You and your eye ...

  9. Distribution of cataract surgical rate and its economic inequality in Iran.

    Science.gov (United States)

    Hashemi, Hassan; Rezvan, Farhad; Fotouhi, Akbar; Khabazkhoob, Mehdi; Gilasi, Hamidreza; Etemad, Koroush; Mahdavi, Alireza; Mehravaran, Shiva; Asgari, Soheila

    2015-06-01

    To determine the distribution of the cataract surgical number per million population per year (CSR), the CSR in the population older than 50 years (CSR 50+) in the provinces of Iran, and their economic inequality in 2010. As part of the cross-sectional 2011 CSR survey, the provincial CSR and CSR 50+ were calculated as the total number of surgeries in major and minor centers divided by the total population and the population older than 50 years in each province. Economic inequality was determined using the average province income, the average urban and rural household incomes, and the percentage of urban and rural population in each province. Tehran and Ilam provinces had the highest and lowest CSR (12,465 vs. 359), respectively. Fars and Ilam provinces had the highest and lowest CSR 50+ (71,381 vs. 2481), respectively. Low CSR (CSR (>5000) was observed in 14 provinces (45.2%) where rates were 0.6 to 59.9% higher than the global target. Cataract surgical rate increased at higher economic quintiles. Differences between the first, second, and fifth (poorest) quintiles were statistically significant. The CSR concentration index was 0.1964 (95% confidence interval, 0.0964 to 0.2964). In line with the goals of the Vision 2020 initiative to eliminate cataract blindness, more than 70% of geographic areas in Iran have achieved the minimum CSR of 3000 or more. However, a large gap still exists in less than 30% of areas, mainly attributed to the economic status.

  10. Cataract removal

    Science.gov (United States)

    ... eye diseases and eye surgery. Adults are usually awake for the procedure. Numbing medicine (local anesthesia) is ... removed. Tips for recovering after cataract surgery: Wear dark sunglasses outside after you remove the patch. Wash ...

  11. Cataract Vision Simulator

    Science.gov (United States)

    ... and Videos: What Do Cataracts Look Like? Cataract Vision Simulator Leer en Español: Simulador: Catarata Jun. 11, 2014 How do cataracts affect your vision? A cataract is a clouding of the eye's ...

  12. Structural and functional properties, chaperone activity and posttranslational modifications of alpha-crystallin and its related subunits in the crystalline lens: N-acetylcarnosine, carnosine and carcinine act as alpha- crystallin/small heat shock protein enhancers in prevention and dissolution of cataract in ocular drug delivery formulations of novel therapeutic agents.

    Science.gov (United States)

    Babizhayev, Mark A

    2012-08-01

    Cataract is a leading cause of blindness worldwide and is responsible for ∼40-80% of the estimated 45 million cases of blindness that occur across the globe. In addition to providing refractive properties to the lens for focusing the image, it is believed that the molecular chaperone function of α-crystallin is essential in preventing the light scattering due to aggregation of other proteins and thus in the maintenance of lens transparency and thereby prevention of cataract. By now, it is fairly acknowledged that chaperoning ability of α-crystallin is instrumental in the maintenance of crystalline lens transparency, and decreased chaperone-like activity of α-crystallin is associated with various types and stages of cataract. A better pharmacological targeting of safeguarding the α-crystallin chaperone activity may aid the development of therapeutic strategies that could evade the need for cataract surgery and revive lens transparency of the cataractous lenses. This article originally summarizes the significance of modulation and enhancing of α-crystallin chaperone activity with imidazole-containing dipeptides N-acetylcarnosine, carnosine and carcinine in consequence to prevent, delay or dissolve the human cataract. A growing evidence and discussion of recent patents are presented in this study that demonstrate the ability of N-acetylcarnosine (lubricant eye drops) or carcinine (lubricant eye drops) (universal antioxidant and deglycation agent) resistant to enzymatic hydrolysis with carnosinase to act as pharmacological chaperones, to decrease oxidative stress and ameliorate oxidative and excessive glycation stress-related eye disease phenotypes, suggesting that the field of chaperone therapy might hold novel treatments for age-related cataracts, age-related macular degeneration (AMD) and ocular complications of diabetes (OCD). The therapeutic strategies are highlighted in the study for identifying potential chaperone compounds and for experimentally

  13. Paediatric cataract: challenges and complications

    Directory of Open Access Journals (Sweden)

    Dr P Vijayalakshmi

    2016-10-01

    Full Text Available Amblyopia should always be anticipated in children with unilateral cataract, asymmetrical bilateral cataracts (or where there is a delay between the first and second eye operation, or a delay of more than a year between diagnosis/ detection and surgery, cataracts with anisometropia or traumatic cataracts with corneal scars. When amblyopia is detected, occlusion therapy (eye patching must be instituted at the earliest opportunity. The patching regimen is the same with any strabismic amblyopia and sometimes needs to be aggressive at the start. It is crucial to explain the need for patching to the parents, since compliance is the greatest obstacle to the success of amblyopia treatment.

  14. Human eye cataract microstructure modeling and its effect on simulated retinal imaging

    Science.gov (United States)

    Fan, Wen-Shuang; Chang, Chung-Hao; Horng, Chi-Ting; Yao, Hsin-Yu; Sun, Han-Ying; Huang, Shu-Fang; Wang, Hsiang-Chen

    2017-02-01

    We designed a crystalline microstructure during cataract lesions and calculated the aberration value of the eye by using ray trace modeling to identify the corresponding spherical aberration, coma aberration, and trefoil aberration value under different pathological-change degrees. The mutual relationship between microstructure and aberration was then discussed using these values. Calculation results showed that with increased layer number of microstructure, the influence of aberration value on spherical aberration was the greatest. In addition, the influence of a relatively compact microstructure on spherical aberration and coma aberration was small, but that on trefoil aberration was great.

  15. Associations between nutrition and cataract.

    Science.gov (United States)

    Taylor, A

    1989-08-01

    Blindness due to opacification of the lens, or cataract, afflicts 50 million persons worldwide. In the United States over 541,000 cataract extractions are done annually at a cost of over $3.8 billion. Conservative estimates indicate that the prevalences of cataracts in Americans aged 65-75 and 75-85 years are 18% and 46%, respectively. Cataracts are even more prevalent in some other populations. It is estimated that the need for cataract extractions would be diminished by half if onset of cataract could be delayed by only ten years. Hypotheses regarding the etiology of cataract include oxidative perturbations of protein metabolism, diverse pathologic conditions, and perhaps glycation of lens proteins. Epidemiologic data indicate that elevated plasma levels of specific nutrients (i.e., carotenoids, ascorbate, tocopherol, and taurine) are associated with diminished incidence of certain types of cataract. Biochemical evidence suggests that each of these compounds can delay photooxidative damage to lens proteins. Roles in lens metabolism for selenium and tryptophan have been suggested. Elucidation of mechanisms by which caloric restriction delays cataract development is a promising area of current research.

  16. Inverse and reciprocity methods for experimental determination of radiation modes.

    NARCIS (Netherlands)

    Berkhoff, Arthur P.; Sarajlic, Edin; Cazzolato, B.S.; Hansen, C.H.

    2001-01-01

    Experimental methods are presented for the problem of finding the vibration patterns of a structure that radi-ate sound most efficiently. These vibration patterns, the so-called radiation modes, diagonalize the acoustic radiation operator and therefore radiate independently. The methods that are

  17. Etiopathogenesis of cataract: An appraisal

    Directory of Open Access Journals (Sweden)

    Varun B Gupta

    2014-01-01

    Full Text Available Natural eye lens is a crystalline substance to produce a clear passage for light. Cataract is opacity within the clear lens of the eye and is the dominant cause of socio-medical problem i.e., blindness worldwide. The only available treatment of cataract is surgery. However, insufficient surgical facilities in poor and developing countries and post-operative complications inspire researchers to find out other modes of treatment for cataract. In this review, an attempt has been made to appraise various etiological factors of cataract to make their perception clear to build up counterpart treatment. Present study is an assortment of various available literatures and electronic information in view of cataract etiopathogenesis. Various risk factors have been identified in development of cataracts. They can be classified in to genetic factors, ageing (systemic diseases, nutritional and trace metals deficiencies, smoking, oxidative stress etc., traumatic, complicated (inflammatory and degenerative diseases of eye, metabolic (diabetes, galactosemia etc., toxic substances including drugs abuses, alcohol etc., radiation (ultraviolet, electromagnetic waves etc. are implicated as significant risk factors in the development of cataract.

  18. Etiopathogenesis of cataract: An appraisal

    Science.gov (United States)

    Gupta, Varun B; Rajagopala, Manjusha; Ravishankar, Basavaiah

    2014-01-01

    Natural eye lens is a crystalline substance to produce a clear passage for light. Cataract is opacity within the clear lens of the eye and is the dominant cause of socio-medical problem i.e., blindness worldwide. The only available treatment of cataract is surgery. However, insufficient surgical facilities in poor and developing countries and post-operative complications inspire researchers to find out other modes of treatment for cataract. In this review, an attempt has been made to appraise various etiological factors of cataract to make their perception clear to build up counterpart treatment. Present study is an assortment of various available literatures and electronic information in view of cataract etiopathogenesis. Various risk factors have been identified in development of cataracts. They can be classified in to genetic factors, ageing (systemic diseases, nutritional and trace metals deficiencies, smoking, oxidative stress etc.), traumatic, complicated (inflammatory and degenerative diseases of eye), metabolic (diabetes, galactosemia etc.), toxic substances including drugs abuses, alcohol etc., radiation (ultraviolet, electromagnetic waves etc.) are implicated as significant risk factors in the development of cataract. PMID:24618482

  19. Comprehensive Management of Pediatric Cataract in Africa

    African Journals Online (AJOL)

    For reprints contact: reprints@medknow.com. REVIEW ARTICLE .... Children are smart: We just have to be smarter. One may use direct and ... of the lens. It is generally larger than a nuclear cataract and develops at a later stage of lens formation than nuclear cataracts. Posterior subcapsular cataract. These are irregular ...

  20. STUDY OF TRAUMATIC CATARACT IN OCCUPATIONAL AND ENVIRONMENTAL TRAUMA AND ITS MANAGEMENT.

    Science.gov (United States)

    Parihar, Jks; Angra, S K; Sen, P R; Verma, S C; Mann, S S

    1998-01-01

    Sixty cases of traumatic cataract in 5 years due to occupational and environmental hazards were studied to highlight mode of trauma, structural damage; management profile and final visual outcome. Thirty six (60%) cases had mechanical trauma whereas 18 (30%) cases had injuries due to non metalic or organic substances. Industrial accidents were responsible in 25 (41.66%) cases. Forty four cases (73.3%) had associated anterior segment injuries. Reconstruction of anterior segment with Posterior Chamber Intraocular lens (PC IOL) implantation could be done in 42 (70%) cases as primary or secondary procedure. Adherent leucoma, iridal trauma, posterior capsular tear and dislocated lens were noted problems. Forty six (76.67%) cases had attained 6/12 or better corrected visual acuity. Defective visual gain was due to corneal opacities and post operative complications.

  1. [Cataract surgery in children].

    Science.gov (United States)

    Pavlović, S

    2000-01-01

    Cataract extraction in children has improved and became more popular over the past few decades but, due to particular features of children's eyes, still remains controversial--especially regarding the intraocular lens implantation. In contrast to adults, indications for cataract surgery in children are much more difficult to determine. Since subjective visual acuity cannot be obtained, greater reliance must be placed on the morphology and location of the lens opacity, and the behavior of the child. Forced preferential looking and visual evoked potentials can be helpful, but they should not be the only criteria. In management of pediatric cataract, correction of postoperative aphakia is still an incompletely resolved problem. Conventionally, optical correction is achieved by spectacles or contact lenses. The power of both spectacles and contact lenses can be readily adjusted to compensate for ocular growth. The success of both depends significantly on parental compliance and the child's acceptance. Hutchinson reported that 44% children with aphakia stopped wearing glasses or contact lenses 2 months after surgery. Contact lens wearing can also result in a number of corneal complications, including infectious keratitis, corneal vascularization and hypoxic corneal ulceration. IOL implantation is theoretically superior to glasses and contact lenses since it provides almost immediate optical correction which is much more reliable because it does not depend on parental or child's compliance. Still, there are many controversies about IOL implantation in infants and young children like IOL-size, material, IOL power calculation, prevention and management of secondary cataract, as well as long term safety of IOLs in children's eyes. Although short-term anatomic results after cataract extraction and primary IOL implantation in children are excellent and stable, long-term follow-up is necessary to answer questions about the long-term safety of implants in children's eyes. A

  2. El estrés oxidativo y su impacto en las cataratas Oxidative stress: its impact on cataracts

    Directory of Open Access Journals (Sweden)

    Yahelín Ferrer Fernández

    2009-12-01

    Full Text Available Las cataratas, una acumulación opaca de proteínas dañadas en el cristalino del ojo, representan la causa principal de disminución visual en aquellas personas de más de 65 años de edad. De hecho, la mayoría de las personas en ese grupo de edad por lo menos presentan el inicio de formación de estas. En dicha afección se han identificado varios factores que predisponen su aparición. Se considera la enfermedad como un proceso multifactorial en cuanto a su agente causal. En los últimos años se ha sugerido que los radicales libres y el estrés oxidativo forman parte de este proceso, hecho que se corrobora en muchas ocasiones, pues se ha demostrado que la utilización preventiva de antioxidantes exógenos o la estimulación de los sistemas antioxidantes endógenos retardan la aparición de los principales signos y síntomas de la enfermedad.Cataracts, an opaque accumulation of damaged proteins in eye lens, are the major cause of visual decrease in those persons aged over 65. In fact, most of persons included in that age group at least have the onset of cataracts. In such affection are identified some factors predisposing its appearance. This disease is considered like a multifactorial process, fact corroborated in many opportunities, since it has demonstrated that the preventive use of exogenous antioxidant or stimulation of endogenous antioxidant systems delays appearance of main signs and symptoms of this disease.

  3. Aging and Health: Cataracts

    Science.gov (United States)

    ... Problems Glaucoma Macular Degeneration Join our e-newsletter! Aging & Health A to Z Cataracts Basic Facts & Information ... Are Cataracts? Cataracts are a common result of aging and occur frequently in older people. About one ...

  4. Cataract production in mice by heavy charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, E.H.; Jose, J.; Yang, V.V.; Barker, M.E.

    1981-03-01

    The cataractogenic effects of heavy charged particles have been evaluated in mice in relation to dose and ionization density (LET/sub infinity/). The study was undertaken due to the high potential for eye exposures to HZE particles among SPS personnel working in outer space. This has made it imperative that the relative biological effectiveness (RBE) in relation to LET/sub infinity/ for various particles be defined so that appropriate quality factors (Q) could be assigned for estimation of risk. Although mice and men differ in susceptibility to radiation-induced cataracts, the results from this project should assist in defining appropriate quality factors in relation to LET/sub infinity/, particle mass, charge, or velocity. Evaluation of results indicated that : (1) low single doses (5 to 20 rad) of iron (/sup 56/Fe) or argon (/sup 40/Ar) particles are cataractogenic at 11 to 18 months after irradiation; (2) onset and density of the opacification are dose related; (3) cataract density (grade) at 9, 11, 13, and 16 months after irradiation shows partial LET/sub infinity/-dependence; and (4) the severity of cataracts is reduced significantly when 417 rad of /sup 60/Co gamma radiation is given in 24 weekly 17 rad fractions compared to giving this radiation as a single dose, but cataract severity is not reduced by fractionation of /sup 12/C doses over 24 weeks.

  5. Characterization and prevalence of cataracts in Labrador Retrievers in The Netherlands.

    Science.gov (United States)

    Kraijer-Huver, Ingrid M G; Gubbels, Ed J; Scholten, Janneke; Djajadiningrat-Laanen, Sylvia C; Boevé, Michael H; Stades, Frans C

    2008-10-01

    To assess the prevalence and distribution of types of cataract, investigate the effects of selective breeding on cataract development, and identify the relationship between posterior polar cataract and other types of cortical cataracts in Labrador Retrievers in The Netherlands. 9,017 Labrador Retrievers. Records of 18,283 ophthalmic examinations performed by veterinary ophthalmologists from 1977 through 2005 were reviewed. There were 522 dogs affected by hereditary cataracts in 1 or both eyes without progressive retinal atrophy (PRA) and 166 PRA-affected dogs with cataracts. These cataracts were divided into 3 groups: posterior polar (triangular) cataract, extensive immature and mature cataract, and a miscellaneous group. Dogs with PRA were analyzed separately. From 1980 through 2000, the prevalence of hereditary cataracts was stable at 8%. The prevalence of cataracts in offspring of cataract-affected dogs was significantly increased, compared with the prevalence in offspring of nonaffected dogs. The distribution of types of cataract was significantly different between dogs with primary cataracts and PRA-affected dogs. Dogs with posterior polar (triangular) cataracts produced affected offspring with the same distribution of types of cataracts as the entire population of primary cataract-affected dogs. Cataract development in the Labrador Retriever population in The Netherlands appears to be a predominantly genetic disorder. Posterior polar (triangular) cataracts appear to be related to other types of hereditary cataract. Although there is no conclusive evidence, it seems valid to continue exclusion of all Labrador Retrievers affected by any type of primary cataract from breeding.

  6. Corneal spherical aberration and its impact on choosing an intraocular lens for cataract surgery.

    Science.gov (United States)

    Al-Sayyari, Tarfah M; Fawzy, Samah M; Al-Saleh, Ahmed A

    2014-10-01

    To analyze the post operative results of targeting zero spherical aberration by selecting the best-fit aspheric intraocular lens (IOL), based on preoperative corneal spherical aberration of patients with phacoemulsification surgery. AlHokama Eye Specialist Center, Riyadh, Saudi Arabia. From the 1st of October 2012 until the 10th of April 2013. Fifty-three eyes, were subjected to phacoemulsification cataract surgery and divided into two groups, 34 eyes were implanted with aspheric IOLs based on their corneal spherical aberration targeting post operative zero total spherical aberration, whereas 19 eyes were implanted with neutral aspheric IOLs regardless of their corneal spherical aberrations (CSAs). As a pre and post routine examination, patients underwent: slit lamp testing, intraocular pressure (IOP) measuring, fundus examination, best spectacle corrected visual acuity (BSCVA), manifest refraction, pupillometry, axial length, contrast sensitivity, and corneal aberration measurement using Pentacam HR (OCULUS, Germany) at the 6-mm optical zone. Post operatively, visual function questionnaire (VF-14) was asked to all patients. Fifty-three eyes of 45 patients, whose age ranged from 45 to 90 years old, were available for analysis, the selected group was implanted with: Tecnis ZA9003 or ZCB00 (Abbott Medical Optics) IOLs in 17 eyes with corneal spherical aberration of more than 0.27 μm, AcrySof IQ SN60WF (Alcon Laboratories Inc.) IOLs were implanted in 4 eyes with CSA = (0.2-0.27) μm, and Rayner 970C, 920H or 620H IOLs with spherical aberration (SA) = 0 in 13 eyes with CSA less than 0.20 μm. The other group of 19 eyes was implanted with aspheric IOLs that have zero spherical aberration (Rayner 970C or 920H) regardless of their CSA. Root mean square (RMS) of total corneal aberration positively correlates to the pupil diameter (P = 0.0031, r = 0.3989). A low negative correlation was found between the corneal spherical aberration of the fourth ordered (Z40

  7. Elevated Frequency of Cataracts in Birds from Chernobyl

    Science.gov (United States)

    Mousseau, Timothy Alexander; Møller, Anders Pape

    2013-01-01

    Background Radiation cataracts develop as a consequence of the effects of ionizing radiation on the development of the lens of the eye with an opaque lens reducing or eliminating the ability to see. Therefore, we would expect cataracts to be associated with reduced fitness in free-living animals. Methodology/Principal Findings We investigated the incidence of lens opacities typical of cataracts in more than 1100 free-living birds in the Chernobyl region in relation to background radiation. The incidence of cataracts increased with level of background radiation both in analyses based on a dichotomous score and in analyses of continuous scores of intensity of cataracts. The odds ratio per unit change in the regressor was 0.722 (95% CI 0.648, 0.804), which was less than odds ratios from investigations of radiation cataracts in humans. The relatively small odds ratio may be due to increased mortality in birds with cataracts. We found a stronger negative relationship between bird abundance and background radiation when the frequency of cataracts was higher, but also a direct effect of radiation on abundance, suggesting that radiation indirectly affects abundance negatively through an increase in the frequency of cataracts in bird populations, but also through direct effects of radiation on other diseases, food abundance and interactions with other species. There was no increase in incidence of cataracts with increasing age, suggesting that yearlings and older individuals were similarly affected as is typical of radiation cataract. Conclusions/Significance These findings suggest that cataracts are an under-estimated cause of morbidity in free-living birds and, by inference, other vertebrates in areas contaminated with radioactive materials. PMID:23935827

  8. Connexin mutants and cataracts

    Directory of Open Access Journals (Sweden)

    Eric C Beyer

    2013-04-01

    Full Text Available The lens is a multicellular, but avascular tissue that must stay transparent to allow normal transmission of light and focusing of it on the retina. Damage to lens cells and/or proteins can cause cataracts, opacities that disrupt these processes. The normal survival of the lens is facilitated by an extensive network of gap junctions formed predominantly of connexin46 and connexin50. Mutations of the genes that encode these connexins (GJA3 and GJA8 have been identified and linked to inheritance of cataracts in human families and mouse lines. In vitro expression studies of several of these mutants have shown that they exhibit abnormalities that may lead to disease. Many of the mutants reduce or modify intercellular communication due to channel alterations (including loss of function or altered gating or due to impaired cellular trafficking which reduces the number of gap junction channels within the plasma membrane. However, the abnormalities detected in studies of other mutants suggest that they cause cataracts through other mechanisms including gain of hemichannel function (leading to cell injury and death and formation of cytoplasmic accumulations (that may act as light scattering particles. These observations and the anticipated results of ongoing studies should elucidate the mechanisms of cataract development due to mutations of lens connexins and abnormalities of other lens proteins. They may also contribute to our understanding of the mechanisms of disease due to connexin mutations in other tissues.

  9. Radiative B Decays -- an Experimental Overview

    OpenAIRE

    Thorndike, Edward H.

    2002-01-01

    An informal review is given of the status and direction of experiments on radiative B decays -- b -> s gamma and b -> d gamma. Branching fractions for exclusive and inclusive b -> s gamma decays, CP asymmetry limits, the photon energy spectrum, and limits on the b -> d gamma exclusive branching fractions are covered, and implications of the measurements discussed.

  10. Synchrotron radiation: its characteristics and applications

    Energy Technology Data Exchange (ETDEWEB)

    Blewett, J. P.; Chasman, R.; Green, G. K.

    1977-01-01

    It has been known for a century that charged particles radiate when accelerated and that relativistic electrons in the energy range between 100 MeV and several GeV and constrained to travel in circular orbits emit concentrated, intense beams with broad continuous spectra that can cover the electromagnetic spectrum from infrared through hard X-rays. Recently the possible applications of this radiation have been appreciated and electron synchrotrons and electron storage rings are now being used in many centers for studies of the properties of matter in the solid, liquid and gaseous states. A brief history is presented of ''synchrotron radiation'' as it is now called. The basic properties of this radiation are described and the world-wide distribution is indicated of facilities for its production. Particular attention is given to the proposed facility at Brookhaven which will be the first major installation to be dedicated only to the production and use of synchrotron radiation. Finally, typical examples are given of applications in the areas of radiation absorption studies, techniques based on scattering of radiation, and advances based on X-ray lithography.

  11. Antidepressants and risk of cataract development: A population-based, nested case-control study.

    Science.gov (United States)

    Chou, Po-Han; Chu, Che-Sheng; Chen, Yi-Huei; Hsu, Min-Yen; Huang, Min-Wei; Lan, Tsuo-Hung; Lin, Ching-Heng

    2017-06-01

    Previous studies demonstrated increased risk of cataract development among users of selective serotonin reuptake inhibitors (SSRIs). However, it remains unknown whether this risk also prevails with the use of other types of antidepressants. The aim of this study was to investigate whether use of antidepressants is associated with an increased risk of cataract development. Moreover, the relationship between binding affinities of serotonin transporter (SERT) of antidepressant and the risk of cataracts is examined. We conducted a nested case-control study using National Health Insurance Research Database in Taiwan. A total of 14,288 patients were included; 7651 in the cataract group and 6637 in the control group. Antidepressant exposure was categorized by type, duration of use, and binding affinities of SERT. The association between antidepressant exposure and cataract development was assessed using conditional logistic regression analysis. The adjusted odds ratios (AORs) for developing cataracts among continuous users of SSRIs, serotonin norepinephrine reuptake inhibitors (SNRIs), and other antidepressants were 1.26 (95% confidence interval (CI): 1.12-1.41, pcataract development. Moreover, continuous users of antidepressants with intermediate SERT binding affinities (AOR: 1.68; 95% CI: 1.10-2.56, p=0.017) were significantly associated with increased risks of cataract development. Several confounding factors such as obesity, multiple drug users, family history of cataracts, substance use, and environmental factors (such as sunlight or radiation exposure) were acquired. We found increased risk of cataract development in patients continuously using antidepressants. Regular ocular evaluations in these patients are warranted. Copyright © 2017. Published by Elsevier B.V.

  12. Radiation efficiency during slow crack propagation: an experimental study.

    Science.gov (United States)

    Jestin, Camille; Lengliné, Olivier; Schmittbuhl, Jean

    2017-04-01

    Creeping faults are known to host a significant aseismic deformation. However, the observations of micro-earthquake activity related to creeping faults (e.g. San Andreas Faults, North Anatolian Fault) suggest the presence of strong lateral variabilities of the energy partitioning between radiated and fracture energies. The seismic over aseismic slip ratio is rather difficult to image over time and at depth because of observational limitations (spatial resolution, sufficiently broad band instruments, etc.). In this study, we aim to capture in great details the energy partitioning during the slow propagation of mode I fracture along a heterogeneous interface, where the toughness is strongly varying in space.We lead experiments at laboratory scale on a rock analog model (PMMA) enabling a precise monitoring of fracture pinning and depinning on local asperities in the brittle-creep regime. Indeed, optical imaging through the transparent material allows the high resolution description of the fracture front position and velocity during its propagation. At the same time, acoustic emissions are also measured by accelerometers positioned around the rupture. Combining acoustic records, measurements of the crack front position and the loading curve, we compute the total radiated energy and the fracture energy. We deduce from them the radiation efficiency, ηR, characterizing the proportion of the available energy that is radiated in form of seismic wave. We show an increase of ηR with the crack rupture speed computed for each of our experiments in the sub-critical crack propagation domain. Our experimental estimates of ηR are larger than the theoretical model proposed by Freund, stating that the radiation efficiency of crack propagation in homogeneous media is proportional to the crack velocity. Our results are demonstrated to be in agreement with existing studies which showed that the distribution of crack front velocity in a heterogeneous medium can be well described by a

  13. Solar cataract: A clinical report | Ahuama | Journal of Health and ...

    African Journals Online (AJOL)

    Solar Ultraviolet radiation is caractogenic, as there is increasing evidence implicating ultraviolet radiation as a risk factor in the aetiology of cataracts. Through absorption from sunlight exposure especially into the violet and of the visible range of the solar spectrum, cataract formation may occur due to physiochemical ...

  14. Overview of the current attempts toward the medical treatment of cataract

    Energy Technology Data Exchange (ETDEWEB)

    Kador, P.F.

    1983-04-01

    A variety of agents are currently available that claim to either prevent, delay, or reverse cataracts associated with aging (senile cataracts), radiation, or diabetes and galactosemia (sugar cataracts). Senile cataract therapy includes formulation containing inorganic salts, nutritional supplements, natural product extracts, sulfhydryl, and sulfonic acid containing compounds and miscellaneous redox and nonsteroidal anti-inflammatory compounds. Agents associated with the treatment of radiation cataracts include antioxidants and free radial scavengers. Aldose reductase inhibitors have been effective in the prevention of sugar cataracts. A summary of these agents and their potential ocular effects are presented.

  15. Experimental observation of strong radiation reaction in the field of an ultra-intense laser

    Science.gov (United States)

    Sarri, G.; Poder, K.; Tamburini, M.; di Piazza, A.; Keitel, C. H.; Zepf, M.

    2017-10-01

    Describing radiation reaction in an electromagnetic field is one of the most fundamental outstanding problems in electrodynamics. It consists of determining the dynamics of a charged particle fully taking into account self-forces (loosely referred to as radiation reaction) resulting from the radiation fields generated by the particle whilst it is accelerated. Radiation reaction has only been invoked to explain the radiative properties of powerful astrophysical objects, such as pulsars and quasars. From a theoretical standpoint, this phenomenon is subject of fervent debate and this impasse is worsened by the lack of experimental data, due to extremely high fields required to trigger these effects. Here, we report on the first experimental evidence of strong radiation reaction during the interaction of an ultra-relativistic electron beam with an intense laser field, beyond a purely classical description.

  16. [History of cataract operations in Hungary].

    Science.gov (United States)

    Marsovszky, László

    2013-11-10

    The history of the cataract operations dates back to thousands of years ago. Initially, surgery was carried out using rudimentary operating techniques resulting in the loss of many eyes. Cataract surgery has evolved immersely and now it is a highly refined surgical practice. Evolution of the cataract surgery was closely linked to broadening of anatomical-pathological knowledge and to the development of the instruments applied. Although Daviel performed the first intentional cataract removal in 1747, almost one hundred years passed before the extracapsular cataract extraction method finally replaced the old couching technique. By the middle of the 20th century, with the progression of the operation techniques and instruments, different forms of intracapsular cataract extraction methods became prevalent. Introduction and widespread use of the artificial intraocular lenses from the second half of the 20th century led to the rediscovery and further perfection of the extracapsular cataract extraction technique. Today, phacoemulsification through small incision, along with the foldable intraocular lenses is the gold standard of cataract surgery. The aim of this study is to present the different cataract surgery methods applied throughout the centuries, as well as the difficulties encountered. It discusses pioneering steps of each era, in order to give a closer look at the most frequently performed surgical intervention in ophthalmology.

  17. Electromagnetic radiation influence on clinical course of experimental wound infection

    Directory of Open Access Journals (Sweden)

    Pronina Е.А.

    2010-09-01

    Full Text Available The article gives close attention to the study of electromagnetic radiation influence (EMR at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide (150 GHz and atmospheric oxygen (129 GHz on the clinical course of experimental wound infection caused by antibiotic-sensitive and antibiotic-resistant strains of Pseudomonas aeruginosa. The panoramic spectrometric measuring complex, developed in Saratov Scientific Research Institute of Measuring Equipment was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the atmospheric oxygen and nitric oxide absorption and radiation molecular spectrum structure. The experiments proved the fact that exposure to radiation at the frequency of molecular spectrum absorption and radiation (MSAR of nitric oxide and atmospheric oxygen had positive impact on the course of traumatic process

  18. Cataract - Multiple Languages

    Science.gov (United States)

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Cataract URL of this page: https://medlineplus.gov/languages/cataract.html Other topics A-Z Expand Section ...

  19. Feasibility study for an epidemiological investigation of the relation between radiation exposure and a cataract disease; Machbarkeitsstudie fuer eine epidemiologische Studie zur Untersuchung des Zusammenhangs von Strahlenbelastung und einer Katarakterkrankung

    Energy Technology Data Exchange (ETDEWEB)

    Hammer, Gael; Scheidemann-Wesp, Ulrike; Wicke, Henryk

    2012-03-15

    The feasibility study for en epidemiological investigation of the relation between radiation exposure and a cataract disease consisted of three working packages. The first package included the definition of the relevant status of science and the development of criteria for evaluation of available studies. The second package concerned the determination of relevant radiation exposed collectives and a preliminary evaluation with respect to the potential adequacy for the study. The third package included a comprehensive study of the assigned appropriate collectives: interventional active physicians and the aviation personnel.

  20. Understanding the dynamics of biological colloids to elucidate cataract formation towards the development of methodology for its early diagnosis

    OpenAIRE

    Yannopoulos, Spyros N.; Petta, Vassiliki

    2008-01-01

    Abstract The eye lens is the most characteristic example of mammalian tissues exhibiting complex colloidal behaviour. In this paper we briefly describe how dynamics in colloidal suspensions can help addressing selected aspects of lens cataract which is ultimately related to the protein self-assembly under pathological conditions. Results from dynamic light scattering of eye lens homogenates over a wide protein concentration were analyzed and the various relaxation modes were identi...

  1. Radiation environment at LEO orbits: MC simulation and experimental data.

    Science.gov (United States)

    Zanini, Alba; Borla, Oscar; Damasso, Mario; Falzetta, Giuseppe

    The evaluations of the different components of the radiation environment in spacecraft, both in LEO orbits and in deep space is of great importance because the biological effect on humans and the risk for instrumentation strongly depends on the kind of radiation (high or low LET). That is important especially in view of long term manned or unmanned space missions, (mission to Mars, solar system exploration). The study of space radiation field is extremely complex and not completely solved till today. Given the complexity of the radiation field, an accurate dose evaluation should be considered an indispensable part of any space mission. Two simulation codes (MCNPX and GEANT4) have been used to assess the secondary radiation inside FO-TON M3 satellite and ISS. The energy spectra of primary radiation at LEO orbits have been modelled by using various tools (SPENVIS, OMERE, CREME96) considering separately Van Allen protons, the GCR protons and the GCR alpha particles. This data are used as input for the two MC codes and transported inside the spacecraft. The results of two calculation meth-ods have been compared. Moreover some experimental results previously obtained on FOTON M3 satellite by using TLD, Bubble dosimeter and LIULIN detector are considered to check the performances of the two codes. Finally the same experimental device are at present collecting data on the ISS (ASI experiment BIOKIS -nDOSE) and at the end of the mission the results will be compared with the calculation.

  2. Nutritional modulation of cataract

    Science.gov (United States)

    Cataract, or lens opacification, remains a major cause of blindness worldwide. Cataracts reduce vision in over eighty million people, causing blindness in eighteen million people. The number afflicted by cataract will increase dramatically as the proportion of the elderly global population increase...

  3. Cataract Surgery Performed by High Frequency LDV Z8 Femtosecond Laser: Safety, Efficacy, and Its Physical Properties

    Directory of Open Access Journals (Sweden)

    Bojan Pajic

    2017-06-01

    Full Text Available Background: The aim of our study was to investigate the safety and efficacy of the LDV Z8 femtosecond laser in cataract surgery compared to the conventional procedure. Methods: This prospective study was performed at the Swiss Eye Research Foundation, Eye Clinic ORASIS, Reinach, Switzerland. The study included 130 eyes from 130 patients: 68 treated with femtosecond laser-assisted cataract surgery (FLACS using the FEMTO LDV Z8 and 62 treated with conventional phacoemulsification. Capsulotomy and lens fragmentation in the laser group were performed with the FEMTO LDV Z8 femtosecond laser system, which employs a new, low-energy, high repetition rate laser process for cataract surgery. In the conventional group, the capsulotomy was performed by a cystotome, and lens fragmentation was achieved by the stop-and-chop. Results: Ease of phacoemulsification (on a 4-point scale, the completeness of capsulotomy (on a 10-point scale, effective phacoemulsification time (seconds, uncorrected distance visual acuity (UCVA, best spectacle-corrected distance visual acuity (BSCVA, spherical equivalent (SE, and safety of the procedure were evaluated. The total follow-up time was three months. Conclusions: FLACS with the FEMTO LDV Z8 system was characterized by complete and reproducible capsulotomy and highly effective lens fragmentation. Postoperative visual outcomes were excellent, and the safety of the procedure was optimal.

  4. Cataract Vision Mimicked By Means Of Protein Denaturation In Egg Albumen

    CERN Document Server

    Mandracchia, Biagio; Ferraro, Pietro

    2015-01-01

    As the world's population ages, cataract-induced visual dysfunction and blindness is on the increase. This is a significant global problem. The most common symptoms of cataracts are glared and blurred vision. Usually, people with cataract have trouble seeing or reading at distance or in low light and also their color perception is altered. Furthermore, cataract is a sneaky disease as it is usually a very slow but progressive process, which creates adaptation so that patients find it difficult to recognize. Moreover, for the doctors it can be very difficult to explain and give comprehensive answers to the patients' symptoms. We built and tested an optic device that uses egg albumen to mimic the optical degradation of the crystalline related cataracts and that is able to visualize how the cataract impairs vision. At best of our knowledge, it is the first experimental system developed at this aim. This can be a valuable tool, which can be of help in education for students in medical sciences as well as to provid...

  5. Induction and Processing of the Radiation-Induced Gamma-H2AX Signal and Its Link to the Underlying Pattern of DSB: A Combined Experimental and Modelling Study.

    Directory of Open Access Journals (Sweden)

    Francesco Tommasino

    Full Text Available We present here an analysis of DSB induction and processing after irradiation with X-rays in an extended dose range based on the use of the γH2AX assay. The study was performed by quantitative flow cytometry measurements, since the use of foci counting would result in reasonable accuracy only in a limited dose range of a few Gy. The experimental data are complemented by a theoretical analysis based on the GLOBLE model. In fact, original aim of the study was to test GLOBLE predictions against new experimental data, in order to contribute to the validation of the model. Specifically, the γH2AX signal kinetics has been investigated up to 24 h after exposure to increasing photon doses between 2 and 500 Gy. The prolonged persistence of the signal at high doses strongly suggests dose dependence in DSB processing after low LET irradiation. Importantly, in the framework of our modelling analysis, this is related to a gradually increased fraction of DSB clustering at the micrometre scale. The parallel study of γH2AX dose response curves shows the onset of a pronounced saturation in two cell lines at a dose of about 20 Gy. This dose is much lower than expected according to model predictions based on the values usually adopted for the DSB induction yield (≈ 30 DSB/Gy and for the γH2AX foci extension of approximately 2 Mbp around the DSB. We show and discuss how theoretical predictions and experimental findings can be in principle reconciled by combining an increased DSB induction yield with the assumption of a larger genomic extension for the single phosphorylated regions. As an alternative approach, we also considered in our model the possibility of a 3D spreading-mechanism of the H2AX phosphorylation around the induced DSB, and applied it to the analysis of both the aspects considered. Our results are found to be supportive for the basic assumptions on which GLOBLE is built. Apart from giving new insights into the H2AX phosphorylation process

  6. Evaluating experimental molecular physics studies of radiation damage in DNA*

    Science.gov (United States)

    Śmiałek, Małgorzata A.

    2016-11-01

    The field of Atomic and Molecular Physics (AMP) is a mature field exploring the spectroscopy, excitation, ionisation of atoms and molecules in all three phases. Understanding of the spectroscopy and collisional dynamics of AMP has been fundamental to the development and application of quantum mechanics and is applied across a broad range of disparate disciplines including atmospheric sciences, astrochemistry, combustion and environmental science, and in central to core technologies such as semiconductor fabrications, nanotechnology and plasma processing. In recent years the molecular physics also started significantly contributing to the area of the radiation damage at molecular level and thus cancer therapy improvement through both experimental and theoretical advances, developing new damage measurement and analysis techniques. It is therefore worth to summarise and highlight the most prominent findings from the AMP community that contribute towards better understanding of the fundamental processes in biologically-relevant systems as well as to comment on the experimental challenges that were met for more complex investigation targets. Contribution to the Topical Issue "Low-Energy Interactions related to Atmospheric and Extreme Conditions", edited by S. Ptasinska, M. Smialek-Telega, A. Milosavljevic, B. Sivaraman.

  7. Molecular Genetics of Cataract

    Science.gov (United States)

    Shiels, Alan; Hejtmancik, J. Fielding

    2017-01-01

    Lens opacities or cataract(s) represent a universally important cause of visual impairment and blindness. Typically, cataract is acquired with aging as a complex disorder involving environmental and genetic risk factors. Cataract may also be inherited with an early onset either in association with other ocular and/or systemic abnormalities or as an isolated lens phenotype. Here we briefly review recent advances in gene discovery for inherited and age-related forms of cataract that are providing new insights into lens development and aging. PMID:26310156

  8. Lutein and cataract: from bench to bedside.

    Science.gov (United States)

    Manayi, Azadeh; Abdollahi, Mohammad; Raman, Thiagarajan; Nabavi, Seyed Fazel; Habtemariam, Solomon; Daglia, Maria; Nabavi, Seyed Mohammad

    2016-10-01

    Cataract is one of the most important leading causes of blindness in the world. Extensive research showed that oxidative stress may play an important role in the initiation and progression of a cataract and other age-related eye diseases. Extra-generation of reactive oxygen and nitrogen species in the eye tissue has been shown as one of the most important risk factors for cataracts and other age-related eye diseases. With respect to this, it can be hypothesized that dietary antioxidants may be useful in the prevention and/or mitigation of cataract. Lutein is an important xanthophyll which is widely found in different vegetables such as spinach, kale and carrots as well as some other foods such as eggs. Lutein is concentrated in the macula and suppresses the oxidative stress in the eye tissues. A plethora of literature has shown that increased lutein consumption has a close correlation with reduction in the incidence of cataract. Despite this general information, there is a negligible number of review articles considering the beneficial effects of lutein on cataracts and age-related eye diseases. The present review is aimed at discussing the role of oxidative stress in the initiation and progression of a cataract and the possible beneficial effects of lutein in maintaining retinal health and fighting cataract. We also provide a perspective on the chemistry, sources, bioavailability and safety of lutein.

  9. Towards experimental validation of an analysis framework for morphing radiators

    Science.gov (United States)

    Bertagne, Christopher L.; Erickson, Lisa R.; Sheth, Rubik B.; Whitcomb, John D.; Hartl, Darren J.

    2016-04-01

    Thermal control is an important aspect of spacecraft design, particularly in the case of crewed vehicles, which must maintain a precise internal temperature at all times in spite of sometimes drastic variations in the external thermal environment and internal heat loads. The successes of the Space Shuttle and International Space Station programs have shown that this can be accomplished in Low Earth Orbit (LEO), however, crewed spacecraft traveling beyond LEO are expected to encounter more challenging thermal conditions with significant variations in both the heat rejection requirements and environment temperature. Such missions will require radiator systems with high turndown ratios, defined as the ratio between the maximum and minimum heat rejection rates achievable by the radiator system. Current radiators are only able to achieve turndown ratios of 3:1, far less than the 12:1 turndown ratio which is expected to be required on future missions. An innovative radiator concept, known as a morphing radiator, uses the temperature-induced shape change of shape memory alloy (SMA) materials to achieve a turndown ratio of at least 12:1. Predicting the thermal and structural behavior of SMA-based morphing radiators is challenging due to the presence of two-way thermomechanical coupling that has not been widely considered in the literature. Previous work has demonstrated the application of a technique known as a partitioned analysis procedure which can be used to simulate the behavior of morphing radiators. This work describes ongoing efforts to evaluate the physical accuracy of this approach by conducting validation studies. A detailed finite element model of a morphing radiator is developed and executed using the framework. Preliminary results show close agreement between the experimental data and model predictions, giving additional confidence in the partitioned approach.

  10. Cataract surgery in ancient Egypt.

    Science.gov (United States)

    Blomstedt, Patric

    2014-03-01

    Ophthalmology was one of the most important specialties in Egyptian medicine, and more specialists are known in this field than in any other. This specialization seems, however, to have been of a purely noninvasive nature. Even though it has been claimed that cataract surgery was performed in pharaonic Egypt, careful analysis of the sources does not support the claim. No example of cataract surgery or of any other invasive ophthalmologic procedure can be found in the original sources. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. Evaluating vision-related quality of life in preoperative age-related cataract patients and analyzing its influencing factors in China: a cross-sectional study.

    Science.gov (United States)

    Zhu, Min; Yu, Jiaming; Zhang, Jinsong; Yan, Qichang; Liu, Yang

    2015-11-07

    To evaluate vision-related quality of life in preoperative age-related cataract patients in China, using the Chinese version of the National Eye Institute Visual Function Questionnaire-25 (CHI-NEI-VFQ-25), together with analyses of its influencing factors. Cataract patients were interviewed using the CHI-NEI-VFQ-25, and their demographic information was recorded. The Cronbach α coefficient was used to determine the internal consistency of the CHI-NEI-VFQ-25. Multi-trait analyses were used to assess construct validity, including item convergent validity and item discriminant validity. The data were evaluated by descriptive statistical analyses, by the Kruskal-Wallis rank sum test, and by multinomial logistic regression. The Cronbach α coefficients were all above 0.8, except for the driving subscale. All items passed the convergent and discriminant validity tests. The composite score was 63.0. The lowest five subscale scores were in general vision (40.0), mental health (37.5), role difficulty (37.5), near vision activities (50.0), and dependence (58.3). Except for the subscale scores of general health and ocular pain, the composite scores and subscale scores were positively associated with the best-corrected visual acuity (BCVA) in the better eye. Multinomial logistic regression showed that sex, age, and educational attainment were significantly associated with the composite score and subscale scores. BCVA in the better eye was the most important determinant associated with the decrease in vision-related quality of life. Visual impairment had more impact on the psychosocial parameter than on the other parameters of the patients' quality of life. Among all the demographic characteristics, including sex, age, and educational attainment, influenced the quality of life in age-related cataract patients.

  12. Experimental investigation of the radiation shielding of a MCP detector in the radiation environment near Europa

    Science.gov (United States)

    Tulej, Marek; Wurz, Peter; Meyer, Stefan; Lasi, Davide; Lüthi, Matthias; Galli, André; Piazza, Daniele; Desorgher, Laurent; Hajdas, Wojciech; Reggiani, Davide; Karlsson, Stefan; Kalla, Leif

    2016-04-01

    The Neutral Ion Mass spectrometer (NIM) is one of the six instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM will conduct detailed measurements of chemical composition of Jovian moon exospheres and is equipped with a sensitive MCP ion detector. To maintain high sensitivity of the NIM instrument, background signals arising from the presence of a large background of penetrating radiation (mostly high-energy electrons and protons) in Jupiter's magnetosphere have to be minimised. We investigate the performance of a layered-Z radiation shield, an Al-Ta-Al sandwich, as a potential shielding against high-energy electrons. The experimental investigations were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute (PSI), Villigen, Switzerland. The facility delivers a particle beam containing e,  and  with an adjustable momentum ranging from 17.5 to 345 MeV/c. The measurements of the induced radiation background generated during the interaction of primary particles with Al-Ta-Al sandwich were conducted by beam diagnostic methods and a MCP detector. Diagnostic methods provided for the characterisation of the beam parameters (beam geometry, flux and intensity) and identification of individual particles in the primary beam and in the flux of secondary particles. The MCP detector measurements provided information on the effects of radiation and the results of these measurements define the performance of the shielding material in reducing the background arising from penetrating radiation. In parallel, we performed modelling studies using GEANT 4 and GRASS methods to identify products of the interaction and predict their fluxes and particle rates at the MCP detector. Combination of the experiment and modelling studies yields detailed characterisation of the radiation effects produced by the interaction of the incident e- in the

  13. Unfolded protein response activation in cataracts.

    Science.gov (United States)

    Torres-Bernal, Beatriz E; Torres-Bernal, Luis Fernando; Gutiérrez-Campos, Rafael R; Kershenobich Stalnikowitz, David D; Barba-Gallardo, Luis Fernando; Chayet, Arturo A; Ventura-Juárez, Javier

    2014-10-01

    To analyze the expression of 78 kDa glucose-regulated protein (GRP78) and activating transcription factor 6 (ATF6), 2 factors in the unfolded protein response (UPR), in age-related and diabetes-associated cataract. Universidad Autónoma de Aguascalientes, Aguascalientes, México. Experimental study. The qualitative and quantitative expression of GRP78 and ATF6 were measured in surgical samples from 11 senile cataracts, 9 diabetic-associated cataracts, and 3 normal lenses. Both proteins were detected by immunofluorescence and immunogold-conjugated antibodies. Quantitative morphometry was used to analyze the differences in GRP78 and ATF6 between samples. The Mann-Whitney test was used for statistical analysis. Scanning electron microscopy showed the characteristic organization of fibers in normal lenses with regular alignment and interdigitation between them. On the other hand, lenses from eyes with senile or diabetic cataract showed the same pattern of misalignment and disorganization of the fibers. Both proteins were detected through immunofluorescence in senile and diabetic cataracts, but not in normal lenses. Immunogold-conjugated antibodies and transmission electron microscopy showed that GRP78 and ATF6 grains were 30% higher and 35% higher, respectively, in diabetic cataracts than in senile cataracts (P<.05). These data show for the first time in humans that GRP78 and ATF6 are present in lens fibers of senile cataracts and diabetic cataracts, establishing that the UPR may be important in the process of cataractogenesis. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  14. Experimental model of cutaneous radiation injury in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Meirelles, Rafael Panisi de Campos [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina; Hochman, Bernardo [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. de Cirurgia; Helene Junior, Americo; Fraga, Murillo Francisco Pires [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Dept. de Cirurgia. Divisao de Cirurgia Plastica; Lellis, Rute [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Divisao de Patologia; Ferreira, Lydia Masako, E-mail: rpcmeirelles@yahoo.com.br, E-mail: lydia.dcir@epm.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Mediciana. Divisao de Cirugia Plastica

    2013-07-01

    Purpose: to describe an experimental model of cutaneous radiation injury in rabbits. Methods: on this study eight six-month-old New Zealand male rabbits, with an average weight of 2.5kg were used. They were distributed in four groups (n=2 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 2000, 3000 and 4500 cGy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. Results: after 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 2000 cGy had a 60-day alopecia and from group 3000 cGy, a 90-day alopecia. After the 30th day, the 3000cGy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. One of the animals from group 4500 cGy died on the 7th day with visceral necrosis. The other from the same group had total skin necrosis. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was observed. Conclusion: The proposed experimental model is reproducible. This study suggests that the dosage 4500cGy is excessive and the 3000 cGy is the most effective for this experimental model of cutaneous radiation injury in rabbits. (author)

  15. Noise Radiation Measure-Sound Power and its Test Methods

    OpenAIRE

    Zeng Xianren; Zuo Yanyan

    2013-01-01

    This study mainly aims to study the characteristics and theory of sound radiation of steady-state vibration. Study shows that sound radiation power of steady-state vibration is constant. And taking excavator for experimental object by hemisphere surface method, the radiated sound power of the excavator is the same as testing the sound pressure on various surfaces based on relevant international standard. Finally, a test method of radiated sound power for cylindrical vibration object is proposed.

  16. Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

    Science.gov (United States)

    Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

    2017-08-01

    Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

  17. Experimental Studies of Carbon Nanotube Materials for Space Radiators

    Science.gov (United States)

    SanSoucie, MIchael P.; Rogers, Jan R.; Craven, Paul D.; Hyers, Robert W.

    2012-01-01

    Game ]changing propulsion systems are often enabled by novel designs using advanced materials. Radiator performance dictates power output for nuclear electric propulsion (NEP) systems. Carbon nanotubes (CNT) and carbon fiber materials have the potential to offer significant improvements in thermal conductivity and mass properties. A test apparatus was developed to test advanced radiator designs. This test apparatus uses a resistance heater inside a graphite tube. Metallic tubes can be slipped over the graphite tube to simulate a heat pipe. Several sub ]scale test articles were fabricated using CNT cloth and pitch ]based carbon fibers, which were bonded to a metallic tube using an active braze material. The test articles were heated up to 600 C and an infrared (IR) camera captured the results. The test apparatus and experimental results are presented here.

  18. Managing the posterior polar cataract: An update

    Directory of Open Access Journals (Sweden)

    Abhay R Vasavada

    2017-01-01

    Full Text Available Posterior polar cataracts (PPC have always been a challenge for cataract surgeons due to their inherently higher propensity for posterior capsule rupture. Over the years, several technical modifications have been suggested to enhance safety and reduce posterior capsule rupture rates in these polar cataracts. This review article tries to present the various techniques and strategies to published in literature to manage PPCs. It also discusses pearls for making surgery more reproducible and consistent, as well as the role of newer diagnostic and surgical technology based on the published literature on the subject.

  19. Internal wave structures in abyssal cataract flows

    Science.gov (United States)

    Makarenko, Nikolay; Liapidevskii, Valery; Morozov, Eugene; Tarakanov, Roman

    2014-05-01

    We discuss some theoretical approaches, experimental results and field data concerning wave phenomena in ocean near-bottom stratified flows. Such strong flows of cold water form everywhere in the Atlantic abyssal channels, and these currents play significant role in the global water exchange. Most interesting wave structures arise in a powerful cataract flows near orographic obstacles which disturb gravity currents by forced lee waves, attached hydraulic jumps, mixing layers etc. All these effects were observed by the authors in the Romanche and Chain fracture zones of Atlantic Ocean during recent cruises of the R/V Akademik Ioffe and R/V Akademik Sergei Vavilov (Morozov et al., Dokl. Earth Sci., 2012, 446(2)). In a general way, deep-water cataract flows down the slope are similar to the stratified flows examined in laboratory experiments. Strong mixing in the sill region leads to the splitting of the gravity current into the layers having the fluids with different densities. Another peculiarity is the presence of critical layers in shear flows sustained over the sill. In the case under consideration, this critical level separates the flow of near-bottom cold water from opposite overflow. In accordance with known theoretical models and laboratory measurements, the critical layer can absorb and reflect internal waves generated by the topography, so the upward propagation of these perturbations is blocked from above. High velocity gradients were registered downstream in the vicinity of cataract and it indicates the existence of developed wave structures beyond the sill formed by intense internal waves. This work was supported by RFBR (grants No 12-01-00671-a, 12-08-10001-k and 13-08-10001-k).

  20. cataract surgical services

    African Journals Online (AJOL)

    In most developing countries where the economy is unable to establish or sustain rehabilitative programs, the blind ... thus making the issue of cataract management a complex one. Even when manpower is available, there ... unit in terms of personnel, money and materials, one may still face problems of cataract harvest.

  1. EXTRACAPSULAR CATARACT EXTRACTION

    African Journals Online (AJOL)

    Cataract is the leading cause of blindness in leprosy patients. Sight restoration to blind leprosy patients prevents them from injuring their anaesthetic limbs. The visual outcome and complications of extracapsular cataract extraction with intraocular lens implant in 42 leprosy and 91 non-leprosy patients were compared.

  2. Training a cataract surgeon

    Directory of Open Access Journals (Sweden)

    M Babar Qureshi

    2014-07-01

    Full Text Available Training in cataract surgery is one of the key factors needed to ensure high quality cataract surgery with good visual outcomes and patient satisfaction. The training has to impart the right skills to the right person by the right trainer and in the right environment.

  3. A computer-aided diagnosis system of nuclear cataract via ranking.

    Science.gov (United States)

    Huang, Wei; Li, Huiqi; Chan, Kap Luk; Lim, Joo Hwee; Liu, Jiang; Wong, Tien Yin

    2009-01-01

    A novel computer-aided diagnosis system of nuclear cataract via ranking is firstly proposed in this paper. The grade of nuclear cataract in a slit-lamp image is predicted based on its neighboring labeled images in a ranked images list, which is achieved using an optimal ranking function. A new ranking evaluation measure is proposed for learning the optimal ranking function via direct optimization. Our system has been tested by a large dataset composed of 1000 slit-lamp images from 1000 different cases. Both experimental results and comparison with several state-of-the-art methods indicate the superiority of our system.

  4. Congenital cataract screening

    Directory of Open Access Journals (Sweden)

    Zhale Rajavi

    2016-01-01

    Full Text Available Congenital cataract is a leading cause of visual deprivation which can damage the developing visual system of a child; therefore early diagnosis, management and long-term follow-up are essential. It is recommended that all neonates be screened by red reflex examination at birth and suspected cases be referred to ophthalmic centers. Early surgery (1 year is highly recommended. After surgery, amblyopia treatment and periodic follow-up examinations should be started as soon as possible to achieve a satisfactory visual outcome. Practitioners should consider the possibility of posterior capsular opacity, elevated intraocular pressure and amblyopia during follow-up, especially in eyes with microphthalmia and/or associated congenital anomalies. All strabismic children should undergo slit lamp examination prior to strabismus surgery to rule out congenital lens opacities. From a social point of view, equal and fair medical care should be provided to all children regardless of gender.

  5. MicroRNAs: new players in cataract

    OpenAIRE

    Yu, Xin; Zheng, Heyi; Chan, Matthew TV; Wu, William Ka Kei

    2017-01-01

    Cataract is the most common cause of blindness worldwide. Multiple factors such as aging, eye injury, diabetes mellitus, ultraviolet exposure, drug use and other ocular diseases are etiologically linked to cataractogenesis. Due to a rapid increase in aging population, age-related cataract has become the leading cause of blindness. Therefore, it is urgent to understand the molecular mechanism underlying cataractogenesis. MicroRNAs (miRNAs) are a group of endogenous, small noncoding RNAs that r...

  6. Astigmatism in cataract surgery.

    Science.gov (United States)

    Luntz, M. H.; Livingston, D. G.

    1977-01-01

    We report on our investigation into astigmatism in 40 eyes following a corneal cataract incision closed with a continuous 10/0 nylon monofilament suture (Ethilon). Immediately after surgery there was astigmatism caused by the nylon suture (suture-induced astigmatism), its severity depending on the tightness of the suture. It ranged from 1 to 10-5 dioptres, the mean value 4-09 dioptres with a standard deviation of +/-2-5. Removing the nylon suture eliminated this astigmatism and within a few weeks the corneal astigmatism correction in 48% of eyes returned to the preoperative level. In 80% of eyes the difference between the final postoperative corneal astigmatism (4 months after removing the continuous suture) and the preoperative astigmatism was 0-75 dioptres or less and the maximum change was 1-5 dioptres. In 40% of eyes the axis of the cylinder changed from a horizontal to an oblique axis but did not change from a with- to against-the-rule axis. The degree of astigmatism remained constant while the suture was in place and in 50% of eyes was equal to or less than 3 dioptres. The mean of the spherical equivalents was 11-31 dioptres with a standard deviation of +/-1-25. A spectacle correction 14 days after operation prescribed either as the mean spherical equivalent (11-50 dioptres) or according to the patient's refraction will give satisfactory vision until the suture is removed 4 months after operation. The degree of astigmatism following a corneal section and continuous nylon suture compares very favourably with astigmatism following other suturing techniques for cataract. Images PMID:326304

  7. Phacoemulsification in posterior polar cataract

    Directory of Open Access Journals (Sweden)

    Servet Cetinkaya

    Full Text Available ABSTRACT Purpose: To evaluate the results and complications of phacoemulsification surgery in eyes with posterior polar cataracts and compare the techniques of viscodissection and hydrodissection. Methods: The medical records of 29 consecutive patients (16 males, 13 females with posterior polar cataracts (44 eyes who had undergone cataract surgery were retrospectively reviewed. Patients were divided into two groups according to the technique used; viscodissection was applied to the experimental group (group 1 and hydrodissection to the control group (group 2. Results: The postoperative best corrected visual acuity (BCVA was 0.19 ± 0.22 logMAR (mean ± standard deviation (range 0.00-0.70 in group 1 and 0.25 ± 0.18 logMAR (range 0.00-0.70 in group 2. Although the mean postoperative BCVA in group 1 was greater than that in group 2, the difference was not statistically significant (p=0.165. The mean postoperative BCVA was significantly greater than the mean preoperative BCVA in both groups (p=0.00. Intraoperatively, posterior capsular rupture occurred during the removal of the cortex in three eyes (13% of group 1 patients, with vitreous loss and anterior vitrectomy in one eye only. In group 2, six eyes (28.5% presented posterior capsular rupture, and anterior vitrectomy was performed because of vitreous loss in three eyes. Although the percentage of posterior capsular rupture was greater in group 2, the difference was not statistically significant (p=0.207. Conclusions: Complications in posterior polar cataract surgeries can be overcome by being careful throughout the surgery and using proper techniques. Viscodissection may be better for avoiding posterior capsular rupture than hydrodissection.

  8. Enhancements after cataract surgery.

    Science.gov (United States)

    Alio, Jorge L; Abdelghany, Ahmed A; Fernández-Buenaga, Roberto

    2015-01-01

    To provide a review of the recent literature on the indications and results of refractive and nonrefractive enhancements after cataract surgery. Laser in-situ keratomileusis proves to be the most accurate procedure to correct residual refractive error after cataract surgery. Other lens-based procedures can be used for the enhancement after cataract surgery but with lower predictability. Depending on the cause of the visual problem, these may be toric intraocular lens (IOL) rotation for excess residual cylinder and IOL exchange for unsatisfied patients with multifocal IOL or for IOL dislocation. Modern lens removal techniques and advanced preoperative diagnostic methods allow most cataract patients to be spectacle-independent for distance and sometimes also for near. Refractive considerations are integrated into modern cataract surgery and these days, patients expect an adequately predicted refractive outcome. Despite such advances in cataract surgery, unsatisfactory refractive and visual outcomes occasionally occur and in these cases, the enhancement after cataract surgery is required to achieve the best final visual outcome.

  9. Cataract Surgery in Uveitis

    Science.gov (United States)

    Agrawal, Rupesh; Murthy, Somashiela; Ganesh, Sudha K.; Phaik, Chee Soon; Sangwan, Virender; Biswas, Jyotimai

    2012-01-01

    Cataract surgery in uveitic eyes is often challenging and can result in intraoperative and postoperative complications. Most uveitic patients enjoy good vision despite potentially sight-threatening complications, including cataract development. In those patients who develop cataracts, successful surgery stems from educated patient selection, careful surgical technique, and aggressive preoperative and postoperative control of inflammation. With improved understanding of the disease processes, pre- and perioperative control of inflammation, modern surgical techniques, availability of biocompatible intraocular lens material and design, surgical experience in performing complicated cataract surgeries, and efficient management of postoperative complications have led to much better outcome. Preoperative factors include proper patient selection and counseling and preoperative control of inflammation. Meticulous and careful cataract surgery in uveitic cataract is essential in optimizing the postoperative outcome. Management of postoperative complications, especially inflammation and glaucoma, earlier rather than later, has also contributed to improved outcomes. This manuscript is review of the existing literature and highlights the management pearls in tackling complicated cataract based on medline search of literature and experience of the authors. PMID:22518338

  10. Cataract Surgery in Uveitis

    Directory of Open Access Journals (Sweden)

    Rupesh Agrawal

    2012-01-01

    Full Text Available Cataract surgery in uveitic eyes is often challenging and can result in intraoperative and postoperative complications. Most uveitic patients enjoy good vision despite potentially sight-threatening complications, including cataract development. In those patients who develop cataracts, successful surgery stems from educated patient selection, careful surgical technique, and aggressive preoperative and postoperative control of inflammation. With improved understanding of the disease processes, pre- and perioperative control of inflammation, modern surgical techniques, availability of biocompatible intraocular lens material and design, surgical experience in performing complicated cataract surgeries, and efficient management of postoperative complications have led to much better outcome. Preoperative factors include proper patient selection and counseling and preoperative control of inflammation. Meticulous and careful cataract surgery in uveitic cataract is essential in optimizing the postoperative outcome. Management of postoperative complications, especially inflammation and glaucoma, earlier rather than later, has also contributed to improved outcomes. This manuscript is review of the existing literature and highlights the management pearls in tackling complicated cataract based on medline search of literature and experience of the authors.

  11. 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.

  12. Modeling of the Autofluorescence Spectra of the Crystalline Lens with Cataract Taking into Account Light Scattering

    Science.gov (United States)

    Shapovalov, K. A.; Salmin, V. V.; Lazarenko, V. I.; Gar‧kavenko, V. V.

    2017-05-01

    The model of the autofluorescence spectrum formation of a crystalline lens taking into account light scattering was presented. Cross sections of extinction, scattering and absorption were obtained numerically for models of normal crystalline lens and cataract according to the Mie theory for polydisperse systems. To validate the model, data on the autofluorescence spectra of the normal lens and cataracts were obtained using an experimental ophthalmologic spectrofluorometer with excitation by UV light emitting diodes. In the framework of the model, the influence of the lens light scattering on the shape of the luminescence spectrum was estimated. It was found that the changes in the fluorescence spectrum of lenses with cataracts can be completely interpreted by the light scattering.

  13. Influence factors of visual quality after phacoemulsification for cataract

    Directory of Open Access Journals (Sweden)

    Zhen-Lin Lin

    2017-12-01

    Full Text Available Cataract refers to the degenerative changes in lens quality caused by various causes of reduced transparency or color change. Surgical treatment is the main treatment modality at present. Among them, phacoemulsification has become the main surgical treatment for cataract because of its advantages such as short operation time, small incision and quicker healing. Today, cataract surgery has gradually shift to refractive surgery, and is no longer simply as cataract surgery. But after cataract phacoemulsification, the symptoms and visual quality are different. The main causes include refractive error, postoperative dry eyes and postoperative corneal astigmatism. This article reviews the factors that influence the visual quality of cataract phacoemulsification and its future trends.

  14. Review of nuclear physics experimental data for space radiation.

    Science.gov (United States)

    Norbury, John W; Miller, Jack

    2012-11-01

    The available nuclear fragmentation data relevant to space radiation studies are reviewed. It is found that there are serious gaps in the data. Helium data are missing in the intervals 280 MeV n-3 GeV n and >15 GeV n. Carbon data are missing >15 GeV n. Iron projectile data are missing at all energies except in the interval 280 MeV n-3 GeV n.

  15. Power-line harmonic radiation - Can it significantly affect the earth's radiation belts

    Science.gov (United States)

    Thorne, R. M.; Tsurutani, B. T.

    1979-01-01

    It has been suggested that harmonic radiation from the earth's 50- and 60-hertz power transmission lines might significantly influence the distribution of electrons in the radiation belts. On the basis of observations presented here, it seems advisable to accept such a hypothesis with caution. New evidence suggests that power-line radiation does not play any major role in the nonadiabatic dynamics of radiation belt electrons.

  16. Mouse models of cataract

    Indian Academy of Sciences (India)

    crystallins (gene symbol: Cryg);; some postnatal, progressive cataracts have been characterized by mutations in the -crystallin encoding genes (Cryb);; mutations in genes coding for membrane proteins like MIP or connexins lead to congenital ...

  17. Viscoless microincision cataract surgery

    Directory of Open Access Journals (Sweden)

    Guy Sallet

    2008-06-01

    Full Text Available Guy SalletDepartment of Opthamology, Aalsters Stedelijk Ziekenhuis, BelgiumAbstract: A cataract surgery technique is described in which incisions, continuous circular capsulorhexis and hydrodissection are made without the use of any viscoelastics. Two small incisions are created through which the different parts of the procedure can take place, maintaining a stable anterior chamber under continuous irrigation. Subsequent bimanual phacoemulsification can be done through these microincisions. At the end of the procedure, an intraocular lens can be inserted through the self-sealing incision under continuous irrigation. 50 consecutive cataract patients were operated on without the use of viscoelastics and then compared with a group of 50 patients who had been helped with viscoelastics. No difference in outcome, endothelial cell count or pachymetry was noted between the two groups. No intraoperative complication was encountered. Viscoless cataract surgery was a safe procedure with potential advantages.Keywords: ophthalmic visco-surgical device, viscoless cataract surgery, microincision

  18. Management of residual refractive error after cataract surgery.

    Science.gov (United States)

    Alio, Jorge L; Abdelghany, Ahmed A; Fernández-Buenaga, Roberto

    2014-07-01

    To provide a review of the recent literature on the management of residual refractive error after cataract surgery. Laser in-situ keratomileusis (LASIK) is the most accurate procedure to correct residual refractive error after cataract surgery. Lens-based procedures, such as intraocular lens (IOL) exchange or piggyback lens implantation, are also possible alternatives in cases with extreme ametropia, corneal abnormalities, or in situations where excimer laser is not available. In this review, we found that Piggyback IOL were safer and more accurate than IOL exchange. Emmetropia is our main target today in modern cataract surgery. Accurate biometric analysis, selection and calculation of the adequate IOL, and modern techniques for cataract surgery all help surgeons to move toward the goal of cataract surgery as a refractive procedure free from refractive error. However, in spite of all these inputs, residual refractive error still occasionally occurs after cataract surgery and LASIK seems to be the most accurate method for its correction.

  19. Experimental study of radiation dose rate at different strategic points of the BAEC TRIGA Research Reactor.

    Science.gov (United States)

    Ajijul Hoq, M; Malek Soner, M A; Salam, M A; Haque, M M; Khanom, Salma; Fahad, S M

    2017-12-01

    The 3MW TRIGA Mark-II Research Reactor of Bangladesh Atomic Energy Commission (BAEC) has been under operation for about thirty years since its commissioning at 1986. In accordance with the demand of fundamental nuclear research works, the reactor has to operate at different power levels by utilizing a number of experimental facilities. Regarding the enquiry for safety of reactor operating personnel and radiation workers, it is necessary to know the radiation level at different strategic points of the reactor where they are often worked. In the present study, neutron, beta and gamma radiation dose rate at different strategic points of the reactor facility with reactor power level of 2.4MW was measured to estimate the rising level of radiation due to its operational activities. From the obtained results high radiation dose is observed at the measurement position of the piercing beam port which is caused by neutron leakage and accordingly, dose rate at the stated position with different reactor power levels was measured. This study also deals with the gamma dose rate measurements at a fixed position of the reactor pool top surface for different reactor power levels under both Natural Convection Cooling Mode (NCCM) and Forced Convection Cooling Mode (FCCM). Results show that, radiation dose rate is higher for NCCM in compared with FCCM and increasing with the increase of reactor power. Thus, concerning the radiological safety issues for working personnel and the general public, the radiation dose level monitoring and the experimental analysis performed within this paper is so much effective and the result of this work can be utilized for base line data and code verification of the nuclear reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Taurin and its secrets in experimental hepatology

    Directory of Open Access Journals (Sweden)

    I.N. Kononov

    2017-09-01

    Full Text Available Taurine is a unique amino acid. It has various biological effects aimed at maintaining physiological homeostasis, including antioxidation, modulation of ion transport, osmoregulation, regulation of neurotransmitters and conjugation of bile acids. Its regulatory effect on the normalization of protein, carbohydrate, electrolyte metabolism, the activity of a number of enzymes and hormones, the energy and recovery processes in the body, the strengthening of the immune system are associated with the stabilizing effect of taurine on the membranes. Its conjugation with bile acids contributes to the colloidal stability of bile, which is extremely necessary to maintain a normal level of cholesterol in the blood. The treatment and prevention of various diseases of the cardiovascular system, liver, obesity, dyslipidemia and atherosclerosis, as well as insulin resistance and manifested diabetes mellitus, eye diseases, neuroses and depressions are associated with the normalization of the exchange of taurine in the liver. The purpose of this article is to draw attention to taurine as a powerful hepatoprotector, based on experimental studies.

  1. Nighttime radiative cooling potential of unglazed and PV/T solar collectors: parametric and experimental analyses

    DEFF Research Database (Denmark)

    Pean, Thibault Quentin; Gennari, Luca; Olesen, Bjarne W.

    2015-01-01

    Nighttime radiative cooling technology has been studied both by means of simulations and experiments, to evaluate its potential and to validate the existing theoretical models used to describe it. Photovoltaic/thermal panels (PV/T) and unglazed solar collectors have been chosen as case studies....... The obtained values showed a good agreement with the ones found in the literature about solar panels or other kinds of heat sinks used for radiative cooling applications. The panels provided a cooling performance per night ranging between 0.2 and 0.9 kWh/m2 of panel. The COP values (defined as the ratio....... An experimental setup has been constructed and tested during summer of 2014, at the Technical University of Denmark. The cooling performance (heat loss) has been measured simultaneously for both types of panels, installed side-by-side. The experimental results have been compared with the results from a commercial...

  2. [Pupil physiology after cataract surgery].

    Science.gov (United States)

    Möller, D E; Buchholz, I; Huebscher, H J

    2000-04-01

    The goal of a cataract operation is to achieve an optimal outcome, which includes a round and functioning pupil. The goal of this study was to analyze the influence of cataract operations on pupils that appear to be normal on slit-lamp examination postoperatively. A videopupillography was performed on 47 eyes of 47 patients after phacoemulsification without complications in the first eye, and on 12 eyes of 12 patients after phacoemulsification without complications in the second eye. After surgery, the first eyes showed a significantly more constricted pupil compared to the non-operated eye independently of the stage of irritation. After surgery of the second eye, this was only observed under near dark conditions. Even the morphologically normal pupil shows a change in motility postoperatively. We believe that the reason for this is the mechanical manipulation of the iris during cataract operation. During this, the sensitive dilator muscle of the pupil is affected, leading to temporary or permanent changes in pupillary function. The change in motility of the contralateral, non-operated eye cannot be easily explained. The pupil size is important for the visual process and alteration of its function allows an evaluation of the quality of the operation.

  3. Corneal topography in cataract surgery.

    Science.gov (United States)

    Martinez, C E; Klyce, S D

    1996-02-01

    Keratometry and corneal topography remain the most important means of evaluating induced corneal changes after surgery and have comparable sensitivities in the paracentral region of the cornea. However, keratometry gives no information about the peripheral cornea or about asymmetry of the cornea. Videokeratography should be performed after cataract surgery in cases in which best-corrected visual acuity is not adequate and there are no other obvious causes for poor vision to determine whether corneal irregularities are present. The recent literature on corneal topographic evaluation of induced astigmatism after cataract surgery suggests that in general, smaller, temporal incisions result in less astigmatism. Preoperatively, corneal topography can be used in the calculation of intraocular lens power as well as incision planning. Postoperatively, it can be used to detect tight sutures, torsion of the wound, internal wound gape, and irregular astigmatism, as well as to guide suture removal. In the future, corneal topography will become increasingly important in the determination of intraocular lens power in difficult cases such as patients undergoing combined cataract extraction and penetrating keratoplasty as well as patients with a history of radial keratotomy or photorefractive surgery.

  4. Persistent strabismus after cataract extraction

    Directory of Open Access Journals (Sweden)

    Dujić Mirjana P.

    2005-01-01

    Full Text Available Background. Transient ocular misalignment as a complication of parabulbar and peribulbar anesthesia has already been reported in the literature. The aim of our study was to present a case of irreversible iatrogenic vertical strabismus after cataract surgery, which had to be operated on. Methods. Clinical and orthoptic evaluation of a female patient with vertical diplopia after phacoemulsification cataract surgery. Results. One week after the uneventful surgery, a 68-year-old patient complained of a sudden vertical deviation in the operated eye. The patient had not had a history of previous motility disorders. On examination, the patient showed hypertropia in the left eye of 15−20 degrees in primary position. Three and 6 months postoperatively, there was no a spontaneous improvement, while the persistent vertical deviation was 40 prism dioptres. Strabismus surgery was required 1 year after the cataract surgery. Conclusion. Diplopia is a complication of peribulbar anesthesia which could be persistent. The superior and inferior rectus muscle are especially vulnerable. Its occurrence may be technique - related and the incidence increases when hyaluronidase is not available.

  5. A critical experimental test of synchrotron radiation theory with 3rd generation light source

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-05-15

    A recent ''beam splitting'' experiment at LCLS apparently demonstrated that after a microbunched electron beam is kicked on a large angle compared to the divergence of the FEL radiation, the microbunching wave front is readjusted along the new direction of motion of the kicked beam. Therefore, coherent radiation from an undulator placed after the kicker is emitted along the kicked direction without suppression. This strong emission of coherent undulator radiation in the kicked direction cannot be explained in the framework of conventional synchrotron radiation theory. In a previous paper we explained this puzzle. We demonstrated that, in accelerator physics, the coupling of fields and particles is based, on the one hand, on the use of results from particle dynamics treated according to the absolute time convention and, on the other hand, on the use of Maxwell equations treated according to the standard (Einstein) synchronization convention. Here lies the misconception which led to the strong qualitative disagreement between theory and experiment. After the ''beam splitting'' experiment at LCLS, it became clear that the conventional theory of synchrotron radiation cannot ensure the correct description of coherent and spontaneous emission from a kicked electron beam, nor the emission from a beam with finite angular divergence, in an undulator or a bending magnet. However, this result requires further experimental confirmation. In this publication we propose an uncomplicated and inexpensive experiment to test synchrotron radiation theory at 3rd generation light sources.

  6. Brain Radiation Information Data Exchange (BRIDE): integration of experimental data from low-dose ionising radiation research for pathway discovery.

    Science.gov (United States)

    Karapiperis, Christos; Kempf, Stefan J; Quintens, Roel; Azimzadeh, Omid; Vidal, Victoria Linares; Pazzaglia, Simonetta; Bazyka, Dimitry; Mastroberardino, Pier G; Scouras, Zacharias G; Tapio, Soile; Benotmane, Mohammed Abderrafi; Ouzounis, Christos A

    2016-05-11

    The underlying molecular processes representing stress responses to low-dose ionising radiation (LDIR) in mammals are just beginning to be understood. In particular, LDIR effects on the brain and their possible association with neurodegenerative disease are currently being explored using omics technologies. We describe a light-weight approach for the storage, analysis and distribution of relevant LDIR omics datasets. The data integration platform, called BRIDE, contains information from the literature as well as experimental information from transcriptomics and proteomics studies. It deploys a hybrid, distributed solution using both local storage and cloud technology. BRIDE can act as a knowledge broker for LDIR researchers, to facilitate molecular research on the systems biology of LDIR response in mammals. Its flexible design can capture a range of experimental information for genomics, epigenomics, transcriptomics, and proteomics. The data collection is available at: .

  7. The possible Bπ molecular state and its radiative decay

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Hong-Wei; Gao, Lei [Tianjin University, School of Science, Tianjin (China); Li, Xue-Qian [Nankai University, School of Physics, Tianjin (China)

    2017-05-15

    Recently, several exotic bosons have been confirmed as multi-quark states. However, there are violent disputes about their inner structures, namely if they are molecular states or tetraquarks, or even mixtures of the two structures. It would be interesting to search experimentally for non-strange four-quark states with open charm or bottom which are lighter than Λ{sub c} or Λ{sub b}. Reasonable arguments indicate that they are good candidates of pure molecular states Dπ or Bπ because pions are the lightest boson. Both Bπ and Dπ bound states do not decay via the strong interaction. The Bπ molecule may decay into B* by radiating a photon, whereas the Dπ molecule can only decay via weak interaction. In this paper we explore the mass spectra of the Bπ molecular states by solving the corresponding instantaneous B-S equation. Then the rate of radiative decay vertical stroke (3)/(2), (1)/(2) right angle → B*γ is calculated and our numerical results indicate that the processes can be measured by the future experiment. We also briefly discuss the Dπ case. Due to the constraint of the final state phase space it can only decay via weak interaction. (orig.)

  8. Radiation. What it is, how it affects us and what we can do about it

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.H.

    1986-01-01

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.).

  9. Measuring aniseikonia using scattering filters to simulate cataract

    Science.gov (United States)

    Wilson, Jason

    2011-12-01

    The relationship between anisometropia and aniseikonia (ANK) is not well understood. Ametropic cataract patients provide a unique opportunity to study this relationship after undergoing emmetropizing lens extraction. Because light scatter may affect ANK measurement in cataract patients, its effect should also be evaluated. The Basic Aniseikonia Test (BAT) was evaluated using afocal size lenses to produce specific changes in retinal height. Several light scattering devices were then evaluated to determine which produced effects most similar to cataract. Contrast sensitivity and visual acuity (VA) losses were measured with each device and compared to those reported in cataract. After determining the most appropriate light scattering device, twenty healthy patients with normal visual function were recruited to perform the BAT using the filters to simulate cataract. Cataract patients were recruited from Vision America and the University of Alabama at Birmingham School of Optometry. Patients between 20 and 75 years of age with at least 20/80 VA in each eye, ≥ 2D ametropia, and normal binocular function were recruited. Stereopsis and ANK were tested and each patient completed a symptom questionnaire. ANK measurements using afocal size lenses indicated that the BAT underestimates ANK, although the effect was minimal for vertical targets and darkened surroundings, as previously reported. Based on VA and contrast sensitivity loss, Vistech scattering filters produced changes most similar to cataract. Results of the BAT using Vistech filters demonstrated that a moderate cataract but not a mild cataract may affect the ANK measurement. ANK measurements on cataract patients indicated that those with ≥ 2 D ametropia in each eye may suffer from induced ANK after the first cataract extraction. With upcoming healthcare reform, unilateral cataract extraction may be covered, but not necessarily bilateral, depending on patient VA in each eye. However, a questionnaire about symptoms

  10. Clinical and experimental studies on effects of chemotherapeutic agents on radiation-induced pulmonary damage

    Energy Technology Data Exchange (ETDEWEB)

    Wadasaki, Kouichi

    1988-12-01

    Clinical and experimental studies were undertaken to evaluate the effects of chemotherapeutic agents on radiation-induced pulmonary damage. In a clinical study, one hundred patients with lung cancer were retrospectively reviewed in terms of the development of radiation pneumonitis. In the patients treated with radiation and chemotherapy except for cisplatinum, radiation pneumonitis occurred more frequently and severely than patients with radiation alone. In an experimental study, male SD rats received 15 Gy radiation to the right lungs with or without injection of chemotherapeutic agents including cisplatinum, adriamycin or peplomycin. Histological changes and hydroxyproline contents of the lungs were evaluated at 2 or 5 months after treatment. Pulmonary damage was severer in rats with radiation and drugs than those with radiation alone. However, rats with cisplatinum had less damage than those with other drugs. In conclusion, radiation-induced pulmonary damage was enhanced by administration of several chemotherapeutic agents. However, cisplatinum seemed to enhance pulmonary damage less than other drugs. (author) 77 refs.

  11. Cataract surgery output and cost of hospitalization for cataract ...

    African Journals Online (AJOL)

    Cataract is the most common cause of curable blindness in. Nigeria”. Nigeria has ... contribution of teaching hospitals to the prevention of blind- ness. Several .... All the adult patients before the age of 40 had extracapsular cataract extraction; those above had intracapsular cataract extraction. The children all had congenital ...

  12. Mammary tumorigenesis by radiation and its prevention

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Makoto; Suzuki, Keiko; Inano, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-06-01

    Since the breast cancer in women emerged as an important risk associated with exposure to ionizing radiation, we have investigated to clarify the relationship between the induction of mammary tumors by irradiation and the developmental stage of the mammary glands that regulated by the action of endocrine hormones. Besides the radiation, epidemiological studies showed that the process of biosynthesis/metabolism of steroid hormones and hyperlipidemia may be associated with an increased risk of mammary carcinogenesis. In this context, we have undertaken investigations to evaluate the anti-carcinogenic activities of dehydroepiandrosterone (DHEA), a major secretory steroid of the adrenal glands, bezafibrate (BEZF), an anti-hyperlipidemic drug derived from clofibrate, and simvastatin (SIMV), a prodrug of a specific inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase, against diethylstilbestrol (DES)-dependent promotion/progression of rat mammary tumors initiated by {gamma}-rays. Pregnant Wistar-MS rats received whole-body irradiation with 2.6 Gy of {gamma}-rays from a {sup 60}Co source at day-20 of pregnancy. The mother rats were fed a diet containing either 0.6% DHEA, 0.15% BEZF or 0.03% SIMV beginning immediately after weaning. They were then implanted subcutaneously with a pellet of DES (3 mg/pellet) in the interscapular area 30 days after termination of nursing and were observed for 1 year for detection of palpable mammary tumors starting from the time of pellet implantation. The administration of dietary DHEA, BEZF or SIMV together with DES implantation in rats irradiated in late pregnancy significantly decreased the total incidence of mammary tumors to 35%, 27% and 36%, respectively, for the 1 year period, while higher tumor incidence (96%, 90% and 88%) was observed in rats fed controldiet. However, neither the number of mammary tumors per tumor-bearing rat nor the latency period in the drug treated groups was different from that observed in the control group

  13. Cataracts after Low-Dose Radiotherapy for Lymphoproliferative Disease of the Ocular Adnexa.

    Science.gov (United States)

    Hashimoto, Sawako; Yoshikawa, Hiroshi; Miyagi, Michiko; Onishi, Yoko; Ohga, Saiji; Asai, Kaori; Ishibashi, Tatsuro

    2017-01-01

    To investigate the interval between low-dose radiotherapy and radiation-induced cataracts, and the factors affecting this interval, in patients with lymphoproliferative disease of the ocular adnexa. A retrospective case series of 73 eyes of 59 patients who underwent radiotherapy from 1996 to 2005 with total doses ranging from 24 to 30 Gy was conducted. We investigated the relationships between the radiation-associated cataract formation intervals and age, gender, diabetes, and the use of corticosteroids. The mean interval was 36 months. None of the patients with lens shield developed cataracts. Age was inversely and significantly and gender was not significantly associated with the interval from first radiotherapy to cataract occurrence. The intervals did not differ significantly according to the presence of diabetes and corticosteroid therapy. The mean interval from the start of radiation therapy to radiation-related cataract formation was 36 months and age was a significant factor affecting this interval.

  14. Inevitable problems of older people: presurgery information effect on anxiety levels in patients undergoing cataract surgery.

    Science.gov (United States)

    Karaman Özlü, Zeynep; Tuğ, Özgür; Çay Yayla, Ayşegül

    2016-05-01

    This study was to determine the effect of preoperative patient training on the concern level of patients who would be undergoing cataract surgery. Cataract is one of the main causes of blindness in the world. Cataract surgery is located among the quite frequently performed surgeries today. This study was an experimental study. The subject pool for this research consisted of patients admitted to the Eskisehir Osmangazi University Medical Faculty Hospital Ophthalmology Department for cataract surgery. The sampling consisted of volunteers who were able to communicate and were deemed suitable patients within the limitations of this study (a total of 100 patients; control group = 50, experimental group = 50). Patient identification forms and the State Trait Anxiety Inventory I-II scale were used as data collection tools. The mean State Trait Anxiety Inventory pretest score for the experimental group was significantly higher than the mean final test score (53·30 ± 7·02 and 27·54 ± 3·25, respectively, p Anxiety Inventory pretest score of the control group was 53·82 ± 7·42 and the mean final test score was 49·22 ± 13·17; there was no significant difference between these average scores (p > 0·05). However, the mean final test scores of the experimental and control groups were significantly different (p informative, educational and planned nursing care had a significant impact on anxiety levels in patients who had cataract surgery. Although it is not implemented in most hospitals, and implementation in some hospitals is unplanned, systematically planned preoperative education should take place as part of standard nursing practices. © 2016 John Wiley & Sons Ltd.

  15. Cataract in the chronically exposed residents of the Techa riverside villages.

    Science.gov (United States)

    Mikryukova, L D; Akleyev, A V

    2017-11-01

    The present study is based on a retrospective analysis of archive data of the Clinical Department of the Urals Research Center for Radiation Medicine that has been established to examine and treat accidentally exposed residents of the Urals Region. All individuals included in this study were examined by an ophthalmologist. The study of cataract incidence has been conducted retrospectively for the period from 1951 till 2000 among chronically exposed residents of the Techa riverside villages (6343 persons). Individual accumulated absorbed doses to soft tissues (analogue of eye dose) reached 1.18 Gy (mean 0.12 Gy) while for 88.9% of the study group the dose did not exceed 0.1 Gy. There was no evidence of the influence of low-dose and low-dose rate on cataract incidence. Excess relative risk of cataract formation per 1 Gy was 0.40 (95% CI -0.43; 1.47). It is noted that 15% of all excess cases were registered in persons with soft tissue dose above 0.3 Gy, though their fraction among all examined persons was only 4.1%. Risk of cataract development significantly increased in exposed individuals with retinal angiosclerosis, diabetes and arterial hypertension.

  16. The impact of age-related cataract on measures of frailty in an aging global population.

    Science.gov (United States)

    Fukuoka, Hideki; Afshari, Natalie A

    2017-01-01

    To review the associations among age-related cataract, frailty, and frailty outcomes (e.g., disabilities). It is predicted that the proportion of the population aged 65 and older, in developed and developing nations alike, will rise until at least 2050. The proportion of patients suffering from cataracts and frailty is expected to increase, as are age-related diseases. Although there are many papers reporting on the association between frailty outcomes, cataract, and visual impairment, there is a relative paucity of papers describing associations between frailty markers, cataract, and visual impairment. Reports regarding the relationship between frailty, visual impairment, cataract, and cataract surgery are limited, but gradually increasing. Further research is expected to clarify the mechanism of visual function or the impact of restored vision on frailty. Evidence for the effect of cataract on frailty and frailty outcomes after restoring vision by cataract surgery remains limited.

  17. Outcome of extra-capsular cataract extraction with posterior ...

    African Journals Online (AJOL)

    posterior chamber intraocular lens implantation performed at a cataract surgical campaign. Tesfaye Haileselassie, Yared Asefa, Samson Bayu, Abebe Bejiga. Abstract. Background: Cataract is the leading cause of blindness and visual impairment in many developing countries. It accounts for 20 million bilaterally blind ...

  18. Prevalence and incidence' of blindness due to agerelated cataract in ...

    African Journals Online (AJOL)

    Objectives. The Bureau for the Prevention of Blindness is responsible for the provision of cataract surgery to the rural indigent population of South Africa. It is important for the Bureau to know both the prevalence and the incidence of cataract blindness in the population. Design, setting and subjects. Blindness prevalence ...

  19. How to Improve Outcome of Paediatric Cataract Surgery in Nigeria ...

    African Journals Online (AJOL)

    Paediatric cataract is an important problem all over the world. In developing countries, it is a major cause of childhood blindness resulting in a considerable level of morbidity, economic loss, and social burden. Managing cataracts in children remains a challenge because treatment is often difficult, due to the several ways in ...

  20. a sudden total loss of vision after routine cataract surgery

    African Journals Online (AJOL)

    David Ofori-Adjei

    2013-06-01

    Jun 1, 2013 ... June 2013. Volume 47, Number 2. GHANA MEDICAL JOURNAL. 96. A SUDDEN TOTAL LOSS OF VISION AFTER ROUTINE CATARACT. SURGERY. S. LARTEY1, P. ... Cataract surgery has its complications. The most feared ... mm Hg on oral nifedipine 40 mg daily who presented with 6/36 vision in both ...

  1. CERN inaugurates its latest experimental facility : ISOLDE

    CERN Document Server

    Rubbia, C; Detraz, C; CERN. Geneva

    1992-05-25

    Leading physicists from all over Europe came to CERN on 26 May to celebrate the inauguration of CERN'S latest experimental facility, ISOLDE (Isotope Separator On-Line) at the Proton Synchrotron Booster. A ceremony was held in the new ISOLDE experimental hall where the participants were welcomed by Prof. C. Rubbia, Director General of CERN. Prof. B. Jonson, of Chalmers University in Göteborg, explained the physics potential of the new installation and Prof. C. Detraz, Director of the Institut National de Physique Nucléaire et Physique des Particules (IN2P3), stressed the importance of the ISOLDE facility for European Nuclar Physics.

  2. The Relationship of age, attitude, knowladge, cost to cataract surgery

    Directory of Open Access Journals (Sweden)

    Aminatul Fitria

    2017-02-01

    Full Text Available Cataract is the leading cause of 51% blindness case in the world. Cataract can only be cured trough surgery, but most people with cataract in Indonesia is not in undergoing surgery due to several factors. The increasing number of cataract victim whose not undergoing any treatment to cure them will resulting in increasing number of blindness case, so blindness cause by cataracts can be a public health problem. This research was conducted to determine the relationship of age, attitudes, knowledge and the cost of the action to perform cataract surgery. This research was an observational analytic study with cross sectional design. The samples were cataract patients in Undaan Eye Hospital Surabaya who were randomly selected using a simple random sampling based on medical records of 60 people. Data collection was done by taking secondary data and interviews to patients. Those variables was analyzed with chi square or Fisher’s exact with significancy level at 95%. The result showed that there were correlation between knowledge (p = 0.017, operating costs (p = 0.001 and attitude (0.000 while age was not related (p = 1.000, the actions to perform cataract surgery. The conclusion from this research was the attitude, knowledge and operating costs related to the actions to perform cataract surgery, while age was not related to the actions to perform cataract surgery. It is recommended to give through leaflets or other media in the lobby for improving patient education, counseling to the patient family, the doctor’s advice to convince patient for surgery. Keywords: practice, surgery, cataract, attitudes, costs

  3. Experimental studies on radiation heat transfer enhancement on a standard muffle furnace

    Directory of Open Access Journals (Sweden)

    Minea Alina Adriana

    2013-01-01

    Full Text Available One of the sources of increased industrial energy consumption is the heating equipment, e.g., furnaces. Their domain of use is very wide and due to its abundance of applications it is key equipment in modern civilization. The present experimental investigations are related to reducing energy consumptions and started from the geometry of a classic manufactured furnace. During this experimental study, different cases have been carefully chosen in order to compare and measure the effects of applying different enhancement methods of the radiation heat transfer processes. The main objective work was to evaluate the behavior of a heated enclosure, when different radiant panels were introduced. The experimental investigation showed that their efficiency was influenced by their position inside the heating area. In conclusion, changing the inner geometry by introducing radiant panels inside the heated chamber leads to important time savings in the heating process.

  4. Ocular safety limits for 1030nm femtosecond laser cataract surgery

    Science.gov (United States)

    Wang, Jenny; Sramek, Christopher; Paulus, Yannis M.; Lavinsky, Daniel; Schuele, Georg; Anderson, Dan; Dewey, David; Palanker, Daniel V.

    2013-03-01

    Application of femtosecond lasers to cataract surgery has added unprecedented precision and reproducibility but ocular safety limits for the procedure are not well-quantified. We present an analysis of safety during laser cataract surgery considering scanned patterns, reduced blood perfusion, and light scattering on residual bubbles formed during laser cutting. Experimental results for continuous-wave 1030 nm irradiation of the retina in rabbits are used to calibrate damage threshold temperatures and perfusion rate for our computational model of ocular heating. Using conservative estimates for each safety factor, we compute the limits of the laser settings for cataract surgery that optimize procedure speed within the limits of retinal safety.

  5. Cataract surgery on post radial keratotomy patients

    Directory of Open Access Journals (Sweden)

    Alessandro Meduri

    2017-07-01

    Full Text Available This study aims to evaluate and to compare three different approaches of cataract surgery to patients with previous radial keratotomy (RK, and to analyze the mechanical properties of the cornea after cataract surgery. Three groups of patients, each one including 8 eyes of patients with 16 RK incisions. The first group includes eyes with the first cataract incision superiorly, the second group in the temporal area, the third group in temporal area and a precautionary stabilizing suture across the RK incision adjacent to the main tunnel. In the first group intraoperative dehiscence occurred in three eyes (37.5%: it required immediate application of a suture. In the second group dehiscence occurred intraoperatively in two radial scars (20%: it required immediate application of a suture. In the third group, no intraoperative dehiscences were observed. The stabilizing suture of the RK incision works safer, with a lower risk of dehiscences and less post-operative astigmatism.

  6. Cataract surgery on post radial keratotomy patients

    Science.gov (United States)

    Meduri, Alessandro; Urso, Mario; Signorino, Giuseppe A.; Rechichi, Miguel; Mazzotta, Cosimo; Kaufman, Stephen

    2017-01-01

    This study aims to evaluate and to compare three different approaches of cataract surgery to patients with previous radial keratotomy (RK), and to analyze the mechanical properties of the cornea after cataract surgery. Three groups of patients, each one including 8 eyes of patients with 16 RK incisions. The first group includes eyes with the first cataract incision superiorly, the second group in the temporal area, the third group in temporal area and a precautionary stabilizing suture across the RK incision adjacent to the main tunnel. In the first group intraoperative dehiscence occurred in three eyes (37.5%): it required immediate application of a suture. In the second group dehiscence occurred intraoperatively in two radial scars (20%): it required immediate application of a suture. In the third group, no intraoperative dehiscences were observed. The stabilizing suture of the RK incision works safer, with a lower risk of dehiscences and less post-operative astigmatism. PMID:28730124

  7. The risk of cataract in relation to metal arc welding

    DEFF Research Database (Denmark)

    Slagor, Rebekka Michaelsen; Dornonville de la Cour, Morten; Bonde, Jens Peter

    2016-01-01

    Objectives: There are indications that solar ultraviolet radiation (UVR) increases the risk of cataract, but there is only circumstantial evidence that metal welding, an important occupational source of UVR exposure, is a risk factor. The objective of this study is to unravel if metal welding......, information on welding was collected from questionnaires and, for both cohorts, information about cataract diagnosis and operation was gathered from Danish national registers. Using Cox regression analysis, the hazard ratio (HR) for cataract diagnosis and/or operation was calculated in the follow-up period.......95–1.21] and the adjusted HR was 1.08 (95% CI 0.95–1.22). Age and diabetes were as expected strong risk factors. Conclusion: We found no increased risk of developing cataract among Danish metal welders who worked with arc welding from 1950–1985. This may be attributed to the effectiveness of personal safety equipment....

  8. Carbon footprint and cost-effectiveness of cataract surgery.

    Science.gov (United States)

    Venkatesh, Rengaraj; van Landingham, Suzanne W; Khodifad, Ashish M; Haripriya, Aravind; Thiel, Cassandra L; Ramulu, Pradeep; Robin, Alan L

    2016-01-01

    This article raises awareness about the cost-effectiveness and carbon footprint of various cataract surgery techniques, comparing their relative carbon emissions and expenses: manual small-incision cataract surgery (MSICS), phacoemulsification, and femtosecond laser-assisted cataract surgery. As the most commonly performed surgical procedure worldwide, cataract surgery contributes significantly to global climate change. The carbon footprint of a single phacoemulsification cataract surgery is estimated to be comparable to that of a typical person's life for 1 week. Phacoemulsification has been estimated to be between 1.4 and 4.7 times more expensive than MSICS; however, given the lower degree of postoperative astigmatism and other potential complications, phacoemulsification may still be preferable to MSICS in relatively resource-rich settings requiring high levels of visual function. Limited data are currently available regarding the environmental and financial impact of femtosecond laser-assisted cataract surgery; however, in its current form, it appears to be the least cost-effective option. Cataract surgery has a high value to patients. The relative environmental impact and cost of different types of cataract surgery should be considered as this treatment becomes even more broadly available globally and as new technologies are developed and implemented.

  9. PEDIATRIC CATARACT SURGERY

    Directory of Open Access Journals (Sweden)

    Vladimir Pfeifer

    2002-12-01

    Full Text Available Background. The paper consists of two parts; the first part concentrates on the theoretical foundation of the PCCC surgical technique, while the second part brings forward the results of the study, in which some techniques of cataract surgery were compared.Methods. The study comprised 22 eyes of 19 children who had their primary cataract surgery performed between 1998 and June 2000. All the patients were operated by one surgeon. Eyes with systemic diseases that cause ectopic lenses were excluded from the study.In the example of 2 eyes, lensectomy without IOL implantation was performed, whereas in others, PC IOLs were implanted. (15 Baush and Lomb Hydroview, length 12.50 mm and 2 Alcon AcrySof, length 13 mm.In 6 eyes, the posterior capsule was left intact (all of the patients were older than 5 years, in 14 eyes PCCC was performed; of these, 13 with and 1 without anterior vitrectomy.Results. Secondary cataract developed in both aphakic eyes, in 3 eyes with intact posterior capsules, and in 2 eyes that had PCCC. Posterior capsule opacification still remains a major problem in pediatric cataract surgery and IOL implantation, but no other postoperative complications were present. The best visual outcome was achieved in posttraumatic cases, and the worst in children who had associated ocular anomalies.Conclusions. After early diagnosis and surgery postoperative treatment is also very important. Correction of residual refractive error and orthoptic-pleoptic treatment is necessary for successful visual rehabilitation.

  10. Mouse models of cataract

    Indian Academy of Sciences (India)

    2009-12-31

    Dec 31, 2009 ... Much of our knowledge about the function of genes in cataracts has been derived from the molecular analysis of spontaneous or induced mutations in the mouse. Mutations affecting the mouse lens can be identified easily by visual inspection, and a remarkable number of mutant lines have been ...

  11. Cataract surgery - slideshow

    Science.gov (United States)

    ... GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Cataract surgery - series—Normal anatomy URL of this page: //medlineplus.gov/ency/presentations/ ...

  12. Exploiting ensemble learning for automatic cataract detection and grading.

    Science.gov (United States)

    Yang, Ji-Jiang; Li, Jianqiang; Shen, Ruifang; Zeng, Yang; He, Jian; Bi, Jing; Li, Yong; Zhang, Qinyan; Peng, Lihui; Wang, Qing

    2016-02-01

    Cataract is defined as a lenticular opacity presenting usually with poor visual acuity. It is one of the most common causes of visual impairment worldwide. Early diagnosis demands the expertise of trained healthcare professionals, which may present a barrier to early intervention due to underlying costs. To date, studies reported in the literature utilize a single learning model for retinal image classification in grading cataract severity. We present an ensemble learning based approach as a means to improving diagnostic accuracy. Three independent feature sets, i.e., wavelet-, sketch-, and texture-based features, are extracted from each fundus image. For each feature set, two base learning models, i.e., Support Vector Machine and Back Propagation Neural Network, are built. Then, the ensemble methods, majority voting and stacking, are investigated to combine the multiple base learning models for final fundus image classification. Empirical experiments are conducted for cataract detection (two-class task, i.e., cataract or non-cataractous) and cataract grading (four-class task, i.e., non-cataractous, mild, moderate or severe) tasks. The best performance of the ensemble classifier is 93.2% and 84.5% in terms of the correct classification rates for cataract detection and grading tasks, respectively. The results demonstrate that the ensemble classifier outperforms the single learning model significantly, which also illustrates the effectiveness of the proposed approach. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Roasting Enhances the Anti-Cataract Effect of Coffee Beans: Ameliorating Selenite-Induced Cataracts in Rats.

    Science.gov (United States)

    Ishimori, Nana; Oguchi, Jun; Nakazawa, Yosuke; Kobata, Kenji; Funakoshi-Tago, Megumi; Tamura, Hiroomi

    2017-06-01

    Coffee is a widely consumed beverage. While recent studies have linked its intake to a reduced risk of cataracts, caffeine is believed to be the key factor for its effect. To know how roasting beans affects the effect of coffee on cataract formation, we investigated the impact roasting using a selenite-induced cataract rat model. Sprague Dawley rats were given a single injection of sodium selenite, which induced formation of nuclear cataracts by day 6, with or without coffee intake (100% coffee, 0.2 mL/day) for following 3 days. The concentrations of glutathione (GSH) and ascorbic acid (AsA) in selenite-induced cataract lenses declined to half that of controls. However, 3 days of coffee intake ameliorated the reduction of GSH and AsA so that concentrations remained at 70-80% that of controls. Roasting enhanced the preventive effect of coffee by further reducing cataract formation and ameliorating selenite-induced reduction of antioxidants. High-performance liquid chromatography analysis revealed degradation of chlorogenic acid and generation of pyrocatechol during the coffee roasting process. We discovered that pyrocatechol, at doses equivalent to that found in dark-roasted coffee, was equally effective as caffeine at reducing cataract formation and ameliorating the reduction of antioxidants. Our results indicate that pyrocatechol, generated during the roasting process, acts as an antioxidant together with caffeine to prevent cataract formation.

  14. IC space radiation effects experimental simulation and estimation methods

    CERN Document Server

    Chumakov, A I; Telets, V A; Gerasimov, V F; Yanenko, A V; Sogoyan, A V

    1999-01-01

    Laboratory test simulation methods are developed for IC response prediction to space radiation. The minimum set of radiation simulators is proposed to investigate IC failures and upsets under space radiation. The accelerated test technique of MOS ICs degradation estimation are developed for low intensity irradiation taking into account temperature variations as well as latent degradation effects. Two-parameter cross section functions are adapted to describe the ion- and proton-induced single event upsets. Non-focused laser irradiation is found to be applicable for single event latchup threshold estimation.

  15. Lens cytoskeleton and after-cataract.

    Science.gov (United States)

    Rafferty, N S; Rafferty, K A

    1992-01-01

    Lens epithelial and other ocular cells contain complex arrays of actin filaments which might be expected to allow them to migrate following injury: specifically into the capsular sac in cases of extracapsular cataract extraction or traumatic cataract. To test the possibility, a culture system was developed using a melanotic strain of mice, in which migrating cells are often 'marked' by melanosomes. Injured lenses were cultured on permeable membranes in contact with nutrient medium, and surrounded by iridial tract fragments. After study by light and electron microscopy, it was established that both pigmented and unpigmented cells migrated from the surrounding explants, apparently along the substrate meniscus, to the outside of the lens capsule and then through the wound to the capsule interior. This study suggests a source of cells in development of after-cataract syndrome.

  16. Clear corneal incision in cataract surgery.

    Science.gov (United States)

    Al Mahmood, Ammar M; Al-Swailem, Samar A; Behrens, Ashley

    2014-01-01

    Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature.

  17. Experimental investigations on radiative properties of two kinds of open-cell porous ceramic materials

    Science.gov (United States)

    Wei, Gaosheng; Huang, Pingrui; Chen, Lin; Xu, Chao; Du, Xiaoze

    2017-06-01

    Open-cell porous ceramic is an ideal volumetric heat absorbing material, and understanding in detail the thermal properties of the material, particularly its radiative properties, is of primary importance for the design and improvement of volumetric solar receivers. This work investigates the radiative properties of open-cell porous ceramic through experiment. Fourier transform infrared spectroscopy (FTIR) was applied to measure the spectral transmittance of open-cell porous ceramic samples with different porosities and cell densities in infrared wavelengths between 2.5 and 25 µm. The results were analyzed to determine the spectral extinction coefficient and Rosseland extinction coefficient, which showed that the radiative properties of porous ceramic are strongly dependent on its microstructure parameters, while the type of material has little influence. The spectral extinction coefficient and Rosseland extinction coefficient both increased with increasing cell density and decreasing porosity. Based on the experimental results, two empirical correlations related to the window diameter and porosity were proposed to predict the Rosseland extinction coefficient of open-cell porous ceramics. Finally, the radiative thermal conductivities of different porous ceramics were studied.

  18. Surgical options for correction of refractive error following cataract surgery.

    Science.gov (United States)

    Abdelghany, Ahmed A; Alio, Jorge L

    2014-01-01

    Refractive errors are frequently found following cataract surgery and refractive lens exchange. Accurate biometric analysis, selection and calculation of the adequate intraocular lens (IOL) and modern techniques for cataract surgery all contribute to achieving the goal of cataract surgery as a refractive procedure with no refractive error. However, in spite of all these advances, residual refractive error still occasionally occurs after cataract surgery and laser in situ keratomileusis (LASIK) can be considered the most accurate method for its correction. Lens-based procedures, such as IOL exchange or piggyback lens implantation are also possible alternatives especially in cases with extreme ametropia, corneal abnormalities, or in situations where excimer laser is unavailable. In our review, we have found that piggyback IOL is safer and more accurate than IOL exchange. Our aim is to provide a review of the recent literature regarding target refraction and residual refractive error in cataract surgery.

  19. meson properties and its leptonic radiative decays

    Indian Academy of Sciences (India)

    Whereas it was realized first in 1992 that such fragmentation functions of the double heavy mesons, being different from that of a light meson or a heavy meson, can be further factorized out a perturbative part, which can be reliably calculated by pQCD [2]. As an important consequence of the 'further' factorization, the ...

  20. Experimental techniques for deflection and radiation studies with bent crystals

    CERN Document Server

    Hasan, Said

    2011-01-01

    What happens when a high energy charged particle crosses an amorphous material? It loses energy by ionization and its trajectory is affected by the multiple Coulomb scattering, being these phenomena originated by uncorrelated collisions with the atoms. If the atoms of the target were distributed according to an ordered scheme, the uncorrelated collisions would turn into a coherent interaction with the whole atomic structure. This is the case of an aligned crystal that, depending on the orientation, is seen as a set of atomic planes or strings by the impinging particles. Planes and strings produce potential wells able to confine the charged particles in a transversal region of the crystal, in the so called channeling condition, so that, bending the crystal, particles are forced to follow the curvature, being deflected. This simple and powerful idea, dating 1979, is at the basis of many theoretical and experimental studies that have proven bent crystals effectiveness, described their possible applications and ...

  1. An experimental search for gamma radiation associated with thunderstorm activity

    Energy Technology Data Exchange (ETDEWEB)

    Fryberger, D.

    1992-11-01

    This experiment is a repeat of an earlier experiment, but with more sensitive apparatus and in a location with a higher incidence of thunderstorm activity. The earlier experiment was undertaken by Ashby and Whitehead to investigate the theory that ball lightning might be associated with the annihilation of small amounts of antimatter, and it yielded some very interesting but inconclusive results. In the course of about 12 months of data taking, four high rate bursts of gamma radiation were detected. These events lasted a few seconds and had many thousands of counts (16500, 5000, 3700, and [gt] 7700. Unfortunately, the association of these gamma ray bursts with thunderstorms or ball lightning was not clearly established, although one of the bursts did occur during a local thunderstorm in rough coincidence with a lightning bolt striking a flagpole about 100 yards from the gamma ray detection crystals. A pulse height spectrum taken for this burst (no spectrum was taken for the other three) exhibited a significant peak, well above background, the energy of which appeared to be compatible with the 511 keV positron annihilation line. While the peak could not be unambiguously attributed to positron annihilation, this certainly appeared to be the most likely source.

  2. An experimental search for gamma radiation associated with thunderstorm activity

    Energy Technology Data Exchange (ETDEWEB)

    Fryberger, D.

    1992-11-01

    This experiment is a repeat of an earlier experiment, but with more sensitive apparatus and in a location with a higher incidence of thunderstorm activity. The earlier experiment was undertaken by Ashby and Whitehead to investigate the theory that ball lightning might be associated with the annihilation of small amounts of antimatter, and it yielded some very interesting but inconclusive results. In the course of about 12 months of data taking, four high rate bursts of gamma radiation were detected. These events lasted a few seconds and had many thousands of counts (16500, 5000, 3700, and {gt} 7700. Unfortunately, the association of these gamma ray bursts with thunderstorms or ball lightning was not clearly established, although one of the bursts did occur during a local thunderstorm in rough coincidence with a lightning bolt striking a flagpole about 100 yards from the gamma ray detection crystals. A pulse height spectrum taken for this burst (no spectrum was taken for the other three) exhibited a significant peak, well above background, the energy of which appeared to be compatible with the 511 keV positron annihilation line. While the peak could not be unambiguously attributed to positron annihilation, this certainly appeared to be the most likely source.

  3. Gigantol from Dendrobium chrysotoxum Lindl. binds and inhibits aldose reductase gene to exert its anti-cataract activity: An in vitro mechanistic study.

    Science.gov (United States)

    Wu, Jie; Li, Xue; Wan, Wencheng; Yang, Qiaohong; Ma, Weifeng; Chen, Dan; Hu, Jiangmiao; Chen, C-Y Oliver; Wei, Xiaoyong

    2017-02-23

    Dendrobium. chrysotoxum Lindl is a commonly used species of medicinal Dendrobium which belongs to the family of Orchidaceae, locally known as "Shihu" or "Huangcao". D. chrysotoxum Lindl is widely known for medicinal values in traditional Chinese medicine as it possesses anti-inflammatory, anti-hyperglycemic induction, antitumor and antioxidant properties. To characterize the interaction between gigantol extracted from D. chrysotoxum Lindl and the AR gene, and determine gigantol's efficacy against cataractogenesis. Human lens epithelial cells (HLECs) were induced by glucose as the model group. Reverse transcription polymerase chain reaction (RT-PCR) was used to assess AR gene expression. Then, the mode of interaction of gigantol with the AR gene was evaluated by UV-visible spectroscopy, atomic force microscope (AFM) and surface-enhanced Raman spectroscopy (SERS). The binding constant was determined by UV-visible. Gigantol depressed AR gene expression in HLECs. UV-visible spectra preliminarily indicated that interaction between the AR gene and gigantol may follow the groove mode, with a binding constant of 1.85×10(3)L/mol. Atomic force microscope (AFM) data indicated that gigantol possibly bound to insert AR gene base pairs of the double helix. Surface-enhanced Raman spectroscopy (SERS) studies further supported these observations. Gigantol extracted from D. chrysotoxum Lindl not only has inhibitory effects on aldose reductase, but also inhibits AR gene expression. These findings provide a more comprehensive theoretical basis for the use of Dendrobium for the treatment of diabetic cataract. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  4. Parallelism in adaptive radiations of experimental Escherichia coli populations.

    Science.gov (United States)

    Saxer, Gerda; Travisano, Michael

    2016-01-01

    Adaptive radiations are major contributors to species diversity. Although the underlying mechanisms of adaptive radiations, specialization and trade-offs, are relatively well understood, the tempo and repeatability of adaptive radiations remain elusive. Ecological specialization can occur through the expansion into novel niches or through partitioning of an existing niche. To test how the mode of resource specialization affects the tempo and repeatability of adaptive radiations, we selected replicate bacterial populations in environments that promoted the evolution of diversity either through niche expansion or through niche partitioning, and in a third low-quality single-resource environment, in which diversity was not expected to evolve. Colony size diversity evolved equally fast in environments that provided ecological opportunities regardless of the mode of resource specialization. In the low-quality environments, diversity did not consistently evolve. We observed the largest fitness improvement in the low-quality environment and the smallest the glucose-limited environment. We did not observe a change in the rate of evolutionary change in either trait or environment, suggesting that the pool of beneficial mutations was not exhausted. Overall, the mode of resource specialization did not affect the tempo or repeatability of adaptive radiations. These results demonstrate the limitations of eco-evolutionary feedbacks to affect evolutionary outcomes. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  5. Mimicking cataract-induced visual dysfunction by means of protein denaturation in egg albumen

    Science.gov (United States)

    Mandracchia, B.; Finizio, A.; Ferraro, P.

    2016-03-01

    As the world's population ages, cataract-induced visual dysfunction and blindness is on the increase. This is a significant global problem. The most common symptoms of cataracts are glared and blurred vision. Usually, people with cataract have trouble seeing and reading at distance or in low light and also their color perception is altered. Furthermore, cataract is a sneaky disease as it is usually a very slow but progressive process, which creates adaptation so that patients find it difficult to recognize. All this can be very difficult to explain, so we built and tested an optical device to help doctors giving comprehensive answers to the patients' symptoms. This device allows visualizing how cataract impairs vision mimicking the optical degradation of the crystalline related cataracts. This can be a valuable optical tool for medical education as well as to provide a method to illustrate the patients how cataract progression process will affect their vision.

  6. "Ant-egg" cataract revisited

    DEFF Research Database (Denmark)

    Clemmensen, Kåre; Enghild, Jan J; Ivarsen, Anders

    2017-01-01

    PURPOSE: Hereditary congenital cataract varies immensely concerning location and form of the lens opacities. A specific and very rare phenotype is called "ant-egg" cataract first described in 1900. "Ant-eggs" have previously been examined using light microscopy, backscattered electron imaging and X......-ray scans and electron microscopy. The purpose of this study was to further characterize "ant-egg" cataract using modern technology and display the history of the "ant-eggs" after cataract extraction. METHODS: "Ant-eggs" were examined using Heidelberg SPECTRALIS Optical Coherence Tomography (OCT......-egg" structures in "ant-egg" cataract. Eighteen of these proteins are not natively found in the human lens. Moreover, "ant-eggs" do not vary over time, after cataract extraction, regarding size and location....

  7. Genetics Home Reference: hyperferritinemia-cataract syndrome

    Science.gov (United States)

    ... Twitter Home Health Conditions Hyperferritinemia-cataract syndrome Hyperferritinemia-cataract syndrome Printable PDF Open All Close All Enable ... to view the expand/collapse boxes. Description Hyperferritinemia-cataract syndrome is a disorder characterized by an excess ...

  8. Analytical and experimental studies of heat pipe radiation cooling of hypersonic propulsion systems

    Science.gov (United States)

    Martin, R. A.; Merrigan, M. A.; Elder, M. G.; Sena, J. T.; Keddy, E. S.; Silverstein, C. C.

    1992-01-01

    Analytical and experimental studies were completed to assess the feasibility of using high-temperature heat pipes to cool hypersonic engine components. This new approach involves using heat pipes to transport heat away from the combustor, nozzle, or inlet regions, and to reject it to the environment by thermal radiation from an external heat pipe nacelle. For propulsion systems using heat pipe radiation cooling (HPRC), it is possible to continue to use hydrocarbon fuels into the Mach 4 to Mach 6 speed range, thereby enhancing the economic attractiveness of commercial or military hypersonic flight. In the second-phase feasibility program recently completed, it is found that heat loads produced by considering both convection and radiation heat transfer from the combustion gas can be handled with HPRC design modifications. The application of thermal insulation to ramburner and nozzle walls was also found to reduce the heat load by about one-half and to reduce peak HPRC system temperatures to below 2700 F. In addition, the operation of HPRC at cruise conditions of around Mach 4.5 and at an altitude of 90,000 ft lowers the peak hot-section temperatures to around 2800 F. An HPRC heat pipe was successfully fabricated and tested at Mach 5 conditions of heat flux, heat load, and temperature.

  9. Laser-assisted cataract surgery and other emerging technologies for cataract removal

    Directory of Open Access Journals (Sweden)

    Aasuri Murali

    1999-01-01

    Full Text Available As we near the end of this century, refractive cataract surgery has become a reality through concerted contributions from ultrasonic phacoemulsification, foldable intraocular lens (IOL implantation technology and keratorefractive surgery. As we enter the new millennium, our sights are set on realizing another dream: accommodative IOL surgery. Towards achieving this goal, many advances have been made in both techniques and technology of cataract removal. Lasers in particular have been under investigation for cataract removal for nearly two decades. The technology has now reached a stage where cataract can indeed be removed entirely with laser alone. Neodymium:YAG and erbium:YAG are the laser sources currently utilized by manufacturers of laser phaco systems. Initial clinical experience reported in the literature has served to highlight the capabilities of lasers and the need for further refinement. Despite the excitement associated with the availability of this alluring new technology for cataract removal, it is necessary to develop more effective laser systems and innovative surgical techniques that optimize its capabilities if laser phaco surgery is to be a genuine improvement over current techniques.

  10. Experimental and theoretical investigation on radiation loss for a fault arc between different material electrodes in an enclosed air tank

    Science.gov (United States)

    Li, Mei; Wu, Yifei; Wu, Yi; Zhao, Daoli

    2017-12-01

    Radiation loss for an air fault arc from different material electrodes in an enclosed tank has been investigated experimentally and theoretically. A hybrid approach by combining a thermopile and photomultiplier was proposed to detect the transient radiated energy. Experiments were made to measure the radiation characteristic of the fault arc between different metal electrodes. The radiated energy accounted for 30%–40%, 50%–60% and 25%–40% of the input electrical energy, respectively, for Cu, Fe and Al electrodes, almost regardless of arc current. The radiation and pressure rise determined experimentally were compared to theoretical values obtained from a 2D model for a fault arc with melting, evaporation and chemical reaction arising from the electrode erosion taken into account. This comparison validated the model and determined a suitable α (an adjusted parameter around the starting temperature of the re-absorption layer) of a semi-empirical radiation model based on the NEC (net emission coefficient) for different electrode erosions with and without considering the influence of metal vapour on radiation. The results show that the radiation enhancement from Cu and Fe vapour has a stronger lowering effect on pressure rise, and for Al it is weaker. When considering the radiation enhancement effect of vapour from Cu, Fe and Al electrodes, α in the radiation model ranges, respectively, from 0.7  <  α  <  0.83, 0.5  <  α  <  0.6 and 0.7  <  α  <  0.83 to 0.83  <  α  <  0.9, 0.6  <  α  <  0.7 and 0.7  <  α  <  0.83.

  11. Antioxidant Capacity of Lenses with Age-Related Cataract

    Directory of Open Access Journals (Sweden)

    Bojana Kisic

    2012-01-01

    Full Text Available The immediate cause of the occurrence of cataract is unknown, but oxidative damage and effects of reactive oxygen species are considered important in its etiopathogenesis. Our research was aimed at testing the nonenzyme antioxidant power of corticonuclear lens blocks, with different types and different maturity of age-related cataract. Clinical and biochemical researches were carried out in 101 patients with age-related cataract. In corticonuclear lens blocks of the patient, the concentration of nonprotein and total-SH groups and the concentration of total vitamin C and dehydroascorbic acid (DHA were determined; the current redox balance of dehydroascorbate/ascorbate and total antioxidant power measured by ferric-reducing ability were examined. In corticonuclear lens blocks with incipient cataract a significantly higher concentration of GSH, total SH groups, concentration of total vitamin C and ascorbic acid (AA, and ferric-reducing ability were measured. The measured concentration of DHA is higher than the concentration of AA in the lenses with the incipient and mature cataract. The concentration ratio of redox couple DHA/AA is higher in lenses with mature cataract, where the measured concentration of AA was lower than in the incipient cataract. Timely removal of DHA from the lens is important because of its potential toxicity as an oxidant. An increase of the current concentration of DHA/AA redox balance can be an indicator of oxidative stress.

  12. Time reversal violation in radiative beta decay: experimental plans

    Science.gov (United States)

    Behr, J. A.; McNeil, J.; Anholm, M.; Gorelov, A.; Melconian, D.; Ashery, D.

    2017-01-01

    Some explanations for the excess of matter over antimatter in the universe involve sources of time reversal violation (TRV) in addition to the one known in the standard model of particle physics. We plan to search for TRV in a correlation between the momenta of the beta, neutrino, and the radiative gamma sometimes emitted in nuclear beta decay. Correlations involving three (out of four) momenta are sensitive at lowest order to different TRV physics than observables involving spin, such as electric dipole moments and spin-polarized beta decay correlations. Such experiments have been done in radiative kaon decay, but not in systems involving the lightest generation of quarks. An explicit low-energy physics model being tested produces TRV effects in the Fermi beta decay of the neutron, tritium, or some positron-decaying isotopes. We will present plans to measure the TRV asymmetry in radiative beta decay of laser-trapped 38mK at better than 0.01 sensitivity, including suppression of background from positron annihilation. Supported by NSERC, D.O.E., Israel Science Foundation. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.

  13. Cataract surgery following KAMRA presbyopic implant

    Directory of Open Access Journals (Sweden)

    Tan TE

    2013-09-01

    Full Text Available Tien-En Tan,1,2 Jodhbir S Mehta2–4 1Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore National Eye Centre, Singapore; 3Singapore Eye Research Institute, Singapore; 4Department of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore Abstract: Intrastromal corneal inlays are an emerging treatment for presbyopic patients. The KAMRA™ small aperture inlay was the first such inlay to receive Conformité Européenne (CE marking in 2005. It has been shown to improve uncorrected near and intermediate visual acuity without adversely affecting uncorrected distance visual acuity. Due to the age of presbyopic patients, they may eventually develop cataracts. In two such cases, we found that cataract surgery with the KAMRA implant left in place was not technically more difficult, and that the surgical procedure could be improved by additional ocular rotations to improve visualization. Biometry readings were reliable, and it appeared that the SRK/T formula was accurate for calculation of intraocular lens power. Cataract surgery with the KAMRA implant left in situ is a viable option for patients. Keywords: cataract surgery, KAMRA, corneal inlay, AcuTarget, presbyopia

  14. Experimental studies and modelling of high radiation and high density plasmas in the ASDEX upgrade tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Casali, Livia

    2015-11-24

    Fusion plasmas contain impurities, either intrinsic originating from the wall, or injected willfully with the aim of reducing power loads on machine components by converting heat flux into radiation. The understanding and the prediction of the effects of these impurities and their radiation on plasma performances is crucial in order to retain good confinement. In addition, it is important to understand the impact of pellet injection on plasma performance since this technique allows higher core densities which are required to maximise the fusion power. This thesis contributes to these efforts through both experimental investigations and modelling. Experiments were conducted at ASDEX Upgrade which has a full-W wall. Impurity seeding was applied to H-modes by injecting nitrogen and also medium-Z impurities such as Kr and Ar to assess the impact of both edge and central radiation on confinement. A database of about 25 discharges has been collected and analysed. A wide range of plasma parameters was achieved up to ITER relevant values such as high Greenwald and high radiation fractions. Transport analyses taking into account the radiation distribution reveal that edge localised radiation losses do not significantly impact confinement as long as the H-mode pedestal is sustained. N seeding induces higher pedestal pressure which is propagated to the core via profile stiffness. Central radiation must be limited and controlled to avoid confinement degradation. This requires reliable control of the impurity concentration but also possibilities to act on the ELM frequency which must be kept high enough to avoid an irreversible impurity accumulation in the centre and the consequent radiation collapse. The key role of the f{sub ELM} is confirmed also by the analysis of N+He discharges. Non-coronal effects affect the radiation of low-Z impurities at the plasma edge. Due to the radial transport, the steep temperature gradients and the ELM flush out, a local equilibrium cannot be

  15. Measurement of scattered radiation in a volumetric 64-slice CT scanner using three experimental techniques

    Energy Technology Data Exchange (ETDEWEB)

    Akbarzadeh, A; Ay, M R; Sarkar, S [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghadiri, H [Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Zaidi, H [Division of Nuclear Medicine, Geneva University Hospital, CH-1211 Geneva (Switzerland)], E-mail: mohammadreza_ay@tums.ac.ir

    2010-04-21

    Compton scatter poses a significant threat to volumetric x-ray computed tomography, bringing cupping and streak artefacts thus impacting qualitative and quantitative imaging procedures. To perform appropriate scatter compensation, it is necessary to estimate the magnitude and spatial distribution of x-ray scatter. The aim of this study is to compare three experimental methods for measurement of the scattered radiation profile in a 64-slice CT scanner. The explored techniques involve the use of collimator shadow, a single blocker (a lead bar that suppresses the primary radiation) and an array blocker. The latter was recently proposed and validated by our group. The collimator shadow technique was used as reference for comparison since it established itself as the most accurate experimental procedure available today. The mean relative error of measurements in all tube voltages was 3.9 {+-} 5.5% (with a maximum value of 20%) for the single blocker method whereas it was 1.4 {+-} 1.1% (with a maximum value of 5%) for the proposed blocker array method. The calculated scatter-to-primary ratio (SPR) using the blocker array method for the tube voltages of 140 kVp and 80 kVp was 0.148 and 1.034, respectively. For a larger polypropylene phantom, the maximum SPR achieved was 0.803 and 6.458 at 140 kVp and 80 kVp, respectively. Although the three compared methods present a reasonable accuracy for calculation of the scattered profile in the region corresponding to the object, the collimator shadow method is by far the most accurate empirical technique. Nevertheless, the blocker array method is relatively straightforward for scatter estimation providing minor additional radiation exposure to the patient.

  16. Cataract Backlog and Output of Cataract Surgery in Plateau State ...

    African Journals Online (AJOL)

    Methodology: All cataract surgical centres in the state were visited. The operation register for the period of one year (1st April 2002 to 31st March 2003) were reviewed and the number of eyes operated for age-related cataract were determined. The number and position of all surgeons were compiled. All surgical eye camps ...

  17. Experimental and Numerical Study on Shock Layer Radiation for Planetary Entry Flights

    OpenAIRE

    山田, 剛治; 吾郷, 祥太; 久保, 優斗; 松野, 隆; 川添, 博光; Yamada, Gouji; Ago, Shota; Kubo, Yuto; Matsuno, Takashi; Kawazoe, Hiromitsu

    2013-01-01

    In this study, shock layer radiation is investigated by experimental and numerical approach. Radiation profiles of N2, N2(+), and N are observed in two test conditions of initial pressure and velocity by time-resolved emission spectroscopy. Flow properties behind shock front are computed by the CFD code with two-temperature thermochemical model. The results are used as inputs for the radiation analysis code “SPRADIAN 2” to derive the radiation profiles behind shock front along the line of sig...

  18. The Effect of Cataract on Eye Movement Perimetry

    Science.gov (United States)

    Thepass, G.; Pel, J. J. M.; Vermeer, K. A.; Creten, O.; Bryan, S. R.; Lemij, H. G.; van der Steen, J.

    2015-01-01

    Purpose. To determine how different grades of cataract affect sensitivity threshold and saccadic reaction time (SRT) in eye movement perimetry (EMP). Methods. In EMP, the visual field is tested by assessing the saccades that a subject makes towards peripheral stimuli using an eye tracker. Forty-eight cataract patients underwent pre- and postoperative EMP examination in both eyes. The subjects had to fix a central stimulus presented on the eye tracker monitor and to look at any detected peripheral stimulus upon its appearance. A multilevel mixed model was used to determine the factors that affected the sensitivity threshold and the SRT as a function of cataract grade. Results. We found no effect of cataract severity (LOCS III grades I through IV) on SRT and the sensitivity thresholds. In cataract of LOCS III grade V, however, we found an increase by 27% and 21% (p < 0.001), respectively, compared to the SRT and the sensitivity threshold in LOCS III grade I. Eyes that underwent cataract surgery showed no change in mean SRTs and sensitivity thresholds after surgery in LOCS III grade IV and lower. Conclusion. The present study shows that EMP can be readily used in patients with cataract with LOCS III grade IV and below. PMID:26078873

  19. The Effect of Cataract on Eye Movement Perimetry

    Directory of Open Access Journals (Sweden)

    G. Thepass

    2015-01-01

    Full Text Available Purpose. To determine how different grades of cataract affect sensitivity threshold and saccadic reaction time (SRT in eye movement perimetry (EMP. Methods. In EMP, the visual field is tested by assessing the saccades that a subject makes towards peripheral stimuli using an eye tracker. Forty-eight cataract patients underwent pre- and postoperative EMP examination in both eyes. The subjects had to fix a central stimulus presented on the eye tracker monitor and to look at any detected peripheral stimulus upon its appearance. A multilevel mixed model was used to determine the factors that affected the sensitivity threshold and the SRT as a function of cataract grade. Results. We found no effect of cataract severity (LOCS III grades I through IV on SRT and the sensitivity thresholds. In cataract of LOCS III grade V, however, we found an increase by 27% and 21% (p<0.001, respectively, compared to the SRT and the sensitivity threshold in LOCS III grade I. Eyes that underwent cataract surgery showed no change in mean SRTs and sensitivity thresholds after surgery in LOCS III grade IV and lower. Conclusion. The present study shows that EMP can be readily used in patients with cataract with LOCS III grade IV and below.

  20. Radiation protection and radiation safety: CERN and its host states to sign a tripartite agreement.

    CERN Multimedia

    2010-01-01

    On 15 November CERN and its Host States will sign a tripartite agreement that replaces the existing bilateral agreements in matters of radiation protection and radiation safety at CERN. It will provide, for the first time, a single forum where the three parties will discuss how maximum overall safety can best be achieved in the specific CERN context.   CERN has always maintained close collaboration with its Host States in matters of safety. “The aim of this collaboration is especially to ensure best practice in the field of radiation protection and the safe operation of CERN’s facilities”, explains Ralf Trant, Head of the Occupational Health & Safety and Environmental Protection (HSE) Unit. Until today, CERN’s collaboration with its Host States was carried out under two sets of bilateral agreements: depending on which side of the French-Swiss border they were being carried out on, a different framework applied to the same activities. This approach has b...

  1. Occupational cataracts and lens opacities in interventional cardiology. The O'CLOC study

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Sophie; Bertrand, Alexandre; Bernier, Marie-Odile [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France). Lab. of Epidemiology

    2010-07-01

    Interventional cardiologists are repeatedly and acutely exposed to scattered ionizing radiation (X-rays) during their diagnostic or therapeutic procedures. These exposures may cause damages to the eye lenses and induce early cataracts known as radiation-induced cataracts. The O'CLOC study is an ongoing epidemiological study designed to test the hypothesis of an increased risk of cataract among interventional cardiologists as compared with unexposed cardiologists. This paper summarizes a detailed article on the O'CLOC study protocol that has been published elsewhere. (orig.)

  2. Radiative transfer model for contaminated slabs : experimental validations

    CERN Document Server

    Andrieu, François; Schmitt, Bernard; Douté, Sylvain; Brissaud, Olivier

    2015-01-01

    This article presents a set of spectro-goniometric measurements of different water ice samples and the comparison with an approximated radiative transfer model. The experiments were done using the spectro-radiogoniometer described in Brissaud et al. (2004). The radiative transfer model assumes an isotropization of the flux after the second interface and is fully described in Andrieu et al. (2015). Two kind of experiments were conducted. First, the specular spot was closely investigated, at high angular resolution, at the wavelength of $1.5\\,\\mbox{\\mu m}$, where ice behaves as a very absorbing media. Second, the bidirectional reflectance was sampled at various geometries, including low phase angles on 61 wavelengths ranging from $0.8\\,\\mbox{\\mu m}$ to $2.0\\,\\mbox{\\mu m}$. In order to validate the model, we made a qualitative test to demonstrate the relative isotropization of the flux. We also conducted quantitative assessments by using a bayesian inversion method in order to estimate the parameters (e.g. sampl...

  3. MRSA and cataract surgery – reflections for practice

    Directory of Open Access Journals (Sweden)

    LF Porter

    2010-10-01

    Full Text Available LF Porter1, RU Khan2, A Hannan3, SP Kelly11Royal Bolton Hospital NHS Foundation Trust, Bolton, UK; 2Departments of Microbiology, Royal Bolton Hospital NHS Foundation Trust, Bolton, UK; 3Haughton Thornley Medical Centers, NHS Tameside and Glossop, UKIntroduction: Postoperative bacterial endophthalmitis is a devastating complication of cataract surgery. Methicillin-resistant Staphylococcus aureus (MRSA endophthalmitis is rare. Recent debate over MRSA screening in United Kingdom (UK National Health Service (NHS hospital services has implications for cataract patients and ophthalmology services.Aims: To discuss issues for clinical practice as based on reflective experience at a UK district general NHS hospital in relation to care of MRSA-positive cataract patients.Methods: Retrospective case series and reflective practice.Results: Three cases presented highlight practice points around cataract patients colonized with MRSA. Known or determined MRSA-colonized patients should be treated with anti-microbial agents at time of cataract surgery known to be active against MRSA. Preventative treatment with intracameral vancomycin or intravenous teicoplanin alongside appropriate topical treatments may be of merit. Importantly fluoroquinolones, often prescribed by cataract surgeons, may have a selective effect favoring the proliferation of MRSA.Conclusion: MRSA screening may cause unnecessary delays in cataract care and may represent a patient safety concern in its own right. Patients colonized with MRSA may safely undergo cataract surgery provided there is no evidence of periorbital infection and provided appropriate infection control and antibiotic prophylaxis measures are used. The well-prepared cataract surgeon needs to be aware of developments in infection control and should liaise with local clinical microbiology colleagues in relation to bacterial resistance to antibiotics.Keywords: methicillin-resistant Staphylococcus aureus (MRSA, endophthalmitis

  4. Experimental study of acoustic radiation force of an ultrasound beam on absorbing and scattering objects

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, Anastasiia V., E-mail: niko200707@mail.ru; Kryzhanovsky, Maxim A.; Tsysar, Sergey A. [Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Kreider, Wayne [Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th St. Seattle WA 98105 (United States); Sapozhnikov, Oleg A. [Department of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation); Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, 1013 NE 40th St. Seattle WA 98105 (United States)

    2015-10-28

    Acoustic radiation force is a nonlinear acoustic effect caused by the transfer of wave momentum to absorbing or scattering objects. This phenomenon is exploited in modern ultrasound metrology for measurement of the acoustic power radiated by a source and is used for both therapeutic and diagnostic sources in medical applications. To calculate radiation force an acoustic hologram can be used in conjunction with analytical expressions based on the angular spectrum of the measured field. The results of an experimental investigation of radiation forces in two different cases are presented in this paper. In one case, the radiation force of an obliquely incident ultrasound beam on a large absorber (which completely absorbs the beam) is considered. The second case concerns measurement of the radiation force on a spherical target that is small compared to the beam diameter.

  5. Visual Outcome of Cataract Surgery

    African Journals Online (AJOL)

    Purpose:To assess the visual outcome of cataract surgery in a tertiary hospital in Nigeria. Methods: Three hundred and seventy eyes (370) that had cataract surgery in the ophthalmology department of. University of Benin Teaching Hospital (UBTH) from. July 2007 to December 2008 were included in the study. Case records ...

  6. Cataract formation after penetrating keratoplasty.

    Science.gov (United States)

    Rathi, V M; Krishnamachary, M; Gupta, S

    1997-05-01

    To assess the incidence and risk factors for developing cataract after penetrating keratoplasty (PKP). L.V. Prasad Eye Institute, Hyderabad, India. This retrospective analysis of 251 phakic patients who had PKP between 1987 and 1994 assessed the incidence of and risk factors for cataract formation. Patients were assigned to one of two groups: Group 1 (n = 96), patients with keratoconus and corneal dystrophy; Group 2 (n = 88), patients with corneal scar and adherent leucoma. Preoperative, intraoperative, and postoperative lens details were noted. Data on intraoperative iris procedures (excess manipulation, pupilloplasty, synechiolysis, peripheral iridectomy) and postoperative topical steroid usage were assessed. Sixty-seven patients were excluded because of incomplete lens status data. Of the remaining 184 patients, 45 (24.45%) developed cataract. Most cataracts (n = 31) developed within the first year of surgery. The incidence of cataract was significantly higher in Group 2 (n = 29) than in Group 1 (n = 16) (P = .0102). There was no significant between-group difference in mean steroid dose (P = .7064); however, the mean dose was significantly higher in eyes with cataracts (563 +/- 234 units) than in those without (479 +/- 127 units) (P = .0352). In Group 2, 9 of 20 patients who had synechiolysis, 1 of 3 who had pupilloplasty, and 2 of 5 who had peripheral iridectomy developed cataract. In Group 1, no patient had iris-related procedures. Excessive steroid use and intraoperative iris manipulations are major risk factors for cataract formation after PKP.

  7. The results of ab interno laser thermal sclerostomy combined with cataract surgery versus trabeculectomy combined with cataract surgery 6 to 12 months postoperatively.

    Science.gov (United States)

    Kendrick, R; Kollarits, C R; Khan, N

    1996-07-01

    When cataract surgery and glaucoma surgery are combined, the theoretical advantages of pressure control, removal of the visual impairment, and protection against an increase in intraocular pressure (IOP) in the immediate postoperative period are gained. The authors' objective was to determine whether ab interno laser thermal sclerostomy (LTS) combined with cataract surgery would be as effective as trabeculectomy combined with cataract surgery. Ab interno LTS was compared with trabeculectomy, retrospectively, for patients who had undergone combined cataract and glaucoma surgery. There was no significant difference in the numbers of patients using no medications or fewer medications at 6 and 12 months. There was a greater reduction in IOP in the LTS group. LTS may be better than trabeculectomy in combined cataract and glaucoma surgery because it reduces the IOP more. Compared with trabeculectomy, LTS is simpler to perform and adds less operating time to cataract surgery. Continued follow-up is recommended.

  8. Modeling silica aerogel optical performance by determining its radiative properties

    Science.gov (United States)

    Zhao, Lin; Yang, Sungwoo; Bhatia, Bikram; Strobach, Elise; Wang, Evelyn N.

    2016-02-01

    Silica aerogel has been known as a promising candidate for high performance transparent insulation material (TIM). Optical transparency is a crucial metric for silica aerogels in many solar related applications. Both scattering and absorption can reduce the amount of light transmitted through an aerogel slab. Due to multiple scattering, the transmittance deviates from the Beer-Lambert law (exponential attenuation). To better understand its optical performance, we decoupled and quantified the extinction contributions of absorption and scattering separately by identifying two sets of radiative properties. The radiative properties are deduced from the measured total transmittance and reflectance spectra (from 250 nm to 2500 nm) of synthesized aerogel samples by solving the inverse problem of the 1-D Radiative Transfer Equation (RTE). The obtained radiative properties are found to be independent of the sample geometry and can be considered intrinsic material properties, which originate from the aerogel's microstructure. This finding allows for these properties to be directly compared between different samples. We also demonstrate that by using the obtained radiative properties, we can model the photon transport in aerogels of arbitrary shapes, where an analytical solution is difficult to obtain.

  9. Modeling silica aerogel optical performance by determining its radiative properties

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2016-02-01

    Full Text Available Silica aerogel has been known as a promising candidate for high performance transparent insulation material (TIM. Optical transparency is a crucial metric for silica aerogels in many solar related applications. Both scattering and absorption can reduce the amount of light transmitted through an aerogel slab. Due to multiple scattering, the transmittance deviates from the Beer-Lambert law (exponential attenuation. To better understand its optical performance, we decoupled and quantified the extinction contributions of absorption and scattering separately by identifying two sets of radiative properties. The radiative properties are deduced from the measured total transmittance and reflectance spectra (from 250 nm to 2500 nm of synthesized aerogel samples by solving the inverse problem of the 1-D Radiative Transfer Equation (RTE. The obtained radiative properties are found to be independent of the sample geometry and can be considered intrinsic material properties, which originate from the aerogel’s microstructure. This finding allows for these properties to be directly compared between different samples. We also demonstrate that by using the obtained radiative properties, we can model the photon transport in aerogels of arbitrary shapes, where an analytical solution is difficult to obtain.

  10. Radiation Monitoring Along The Creeks Of Calabar River And Its ...

    African Journals Online (AJOL)

    The study reveals equivalent dose rate of 0.007µSv/hr and 0.115µSv/hr within the river and its environs respectively. Subsequently, the values are considered far below the radiation limits of 1mSv stipulated for members of public per year. KEY WORDS: Gamma-ray, radiological assessment, Calabar river, Environs, ...

  11. Experimental verification of isotropic radiation from a coherent dipole source via electric-field-driven LC resonator metamaterials.

    Science.gov (United States)

    Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André

    2013-09-27

    It has long been conjectured that isotropic radiation by a simple coherent source is impossible due to changes in polarization. Though hypothetical, the isotropic source is usually taken as the reference for determining a radiator's gain and directivity. Here, we demonstrate both theoretically and experimentally that an isotropic radiator can be made of a simple and finite source surrounded by electric-field-driven LC resonator metamaterials designed by space manipulation. As a proof-of-concept demonstration, we show the first isotropic source with omnidirectional radiation from a dipole source (applicable to all distributed sources), which can open up several possibilities in axion electrodynamics, optical illusion, novel transformation-optic devices, wireless communication, and antenna engineering. Owing to the electric- field-driven LC resonator realization scheme, this principle can be readily applied to higher frequency regimes where magnetism is usually not present.

  12. [Infantile cataract and surgical management].

    Science.gov (United States)

    Milazzo, S; Turut, P; Brémond-Gignac, D

    2011-03-01

    The cataract or opacification of the lens raises, in the child, two problems: of clinical diagnosis but especially of action to be taken therapeutic in particular surgical in front of a juvenille lens. This leads to a step and a therapeutic strategy, which must, individually, weigh the advantages and the disadvantages of the surgery. It is a frequent cause of visual handicap in the child. In the event of unilaterality, the major risks are the amblyopia and the aniseiconia. The elements to be analyzed are linked or the bilaterality, the type and the importance of opacity, local or general associated malformations, precocity diagnoses, and with regard to the treatment, the potential surgical complications, the quality of the optical correction, the postoperative assumption of responsibility and the cooperation of the parents. In all the cases, it will always be necessary to treat the functional part of the amblyopia. Copyright © 2011. Published by Elsevier Masson SAS.

  13. Calculation of the Scattered Radiation Profile in 64 Slice CT Scanners Using Experimental Measurement

    Directory of Open Access Journals (Sweden)

    Afshin Akbarzadeh

    2009-06-01

    Full Text Available Introduction: One of the most important parameters in x-ray CT imaging is the noise induced by detected scattered radiation. The detected scattered radiation is completely dependent on the scanner geometry as well as size, shape and material of the scanned object. The magnitude and spatial distribution of the scattered radiation in x-ray CT should be quantified for development of robust scatter correction techniques. Empirical methods based on blocking the primary photons in a small region are not able to extract scatter in all elements of the detector array while the scatter profile is required for a scatter correction procedure. In this study, we measured scatter profiles in 64 slice CT scanners using a new experimental measurement. Material and Methods: To measure the scatter profile, a lead block array was inserted under the collimator and the phantom was exposed at the isocenter. The raw data file, which contained detector array readouts, was transferred to a PC and was read using a dedicated GUI running under MatLab 7.5. The scatter profile was extracted by interpolating the shadowed area. Results: The scatter and SPR profiles were measured. Increasing the tube voltage from 80 to 140 kVp resulted in an 80% fall off in SPR for a water phantom (d=210 mm and 86% for a polypropylene phantom (d = 350 mm. Increasing the air gap to 20.9 cm caused a 30% decrease in SPR. Conclusion: In this study, we presented a novel approach for measurement of scattered radiation distribution and SPR in a CT scanner with 64-slice capability using a lead block array. The method can also be used on other multi-slice CT scanners. The proposed technique can accurately estimate scatter profiles. It is relatively straightforward, easy to use, and can be used for any related measurement.

  14. Establishment of Experimental Equipment for Training of Professionals in the Nuclear Radiation Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, S. K.; Seo, K. W.; Joo, Y. C.; Kim, I. C.; Woo, C. K.; Yoo, B. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-09-15

    The main purpose of this project is to establish experimental equipment for training of professionals and students in the field of radiation measurement, and settle the foundation for the advanced education system and program. The priority for the experimental equipment had been deduced by reviewing of the Nuclear Training and Education Center of KAERI and other country's training courses. Equipment for training of radiation professionals are High-Purity Germanium spectroscopic systems, alpha analyzers, and hand-held gamma/neutron inspector systems. For the basic experiments, electric personal dosimeters and a reader, radiation survey meters, and various alpha, beta and gamma radiation isotopes have been equipped. Some old or disused equipment and devices were disposed and re-arranged, and a new experiment lab had been settled for gamma spectroscopy. Along with the preparation of equipment, 14 experimental modules have been selected for practical and essential experiments training to professionals from industries, universities and research organizations. Among the modules, 7 important experiment notes had been prepared in Korea and also in English. As a consequence, these advanced radiation experimental setting would be a basis to cooperate with IAEA or other countries for international training courses. These activities would be a foundation for our contribution to the international nuclear society and for improving our nuclear competitiveness. The experimental equipment and application notes developed in this study will be used also by other training institutes and educational organizations through introducing and encouraging to use them to the nuclear society.

  15. The Russian radiation legacy: its integrated impact and lessons.

    Science.gov (United States)

    Goldman, M

    1997-01-01

    Information about the consequences of human exposure to radiation in the former Soviet Union has recently become available. These data add new insights and provide possible answers to several important questions regarding radiation and its impact on occupational and public health. The 1986 Chernobyl accident initiated a major and early increase in childhood thyroid cancer that resulted from ingestion of iodine-131 (131I) by young children living in the most heavily contaminated areas of Belarus, Ukraine, and Russia. No significant additional cancer or other adverse medical effects have yet been reported in the affected populations and among clean-up workers. Major psychological stress independent of radiation dose has been observed in those people thought to be exposed. During the early days of the atomic energy program in the former Soviet Union, some unfortunate events occurred. The country's first atomic test in Semipalatinsk in 1949 exposed over 25,000 people downwind from the blast to significant doses of fission products, especially 131I. During the late 1940s and the early 1950s nuclear material production facilities were developed near Chelyabinsk in the South Ural Mountains, which resulted in major releases into the environment and significant overexposures for thousands of workers and nearby populations. Chronic radiation sickness was observed early in exposed workers, and increases in leukemia and other cancers were also reported. The series of plutonium inhalation-related lung cancers and fatalities among workers exposed in that first decade appears to be unique. Long-term consequences of chronic radiation sickness and four decades of follow-up are being described for the first time. Villagers downstream from the plant consumed high levels of 137Cs and 90Sr and, it is reported, manifested increases in leukemia from internal and external exposures. Although the 40-year databases for retrospective dosimetry epidemiology studies are just beginning to be

  16. Combined surgery versus cataract surgery alone for eyes with cataract and glaucoma

    Science.gov (United States)

    Zhang, Mingjuan Lisa; Hirunyachote, Phenpan; Jampel, Henry

    2016-01-01

    Background Cataract and glaucoma are leading causes of blindness worldwide, and their co-existence is common in elderly people. Glaucoma surgery can accelerate cataract progression, and performing both surgeries may increase the rate of postoperative complications and compromise the success of either surgery. However, cataract surgery may independently lower intraocular pressure (IOP), which may allow for greater IOP control among patients with co-existing cataract and glaucoma. The decision between undergoing combined glaucoma and cataract surgery versus cataract surgery alone is complex. Therefore, it is important to compare the effectiveness of these two interventions to aid clinicians and patients in choosing the better treatment approach. Objectives To assess the relative effectiveness and safety of combined surgery versus cataract surgery (phacoemulsification) alone for co-existing cataract and glaucoma. The secondary objectives include cost analyses for different surgical techniques for co-existing cataract and glaucoma. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2014), EMBASE (January 1980 to October 2014), PubMed (January 1948 to October 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to October 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 3 October 2014. We checked the reference lists of the included trials to identify further relevant trials. We used the Science

  17. Nutraceuticals in prevention of cataract – An evidence based approach

    Directory of Open Access Journals (Sweden)

    Amandeep Kaur

    2017-01-01

    Full Text Available Cataract is a principal cause of blindness in the world and is characterized by clouding of eye’s natural lens. Surgery is the major therapeutic step taken to cure cataract; however, it is having its own limitations and complications such as iris prolapse, raised IOP, infection, cystoid macular edema and posterior capsular opacification (PCO. So world is looking toward more robust and natural ways to prevent cataract. One of the important factors that can play a role in prevention of any and many diseases is diet of the people. The inclusion of certain naturally occurring food and nutraceuticals is coming up as a best alternative for curing cataract because of their presumed safety, potential nutritional and therapeutic effects. Some nutraceuticals can act as an anticataract agent through some or the other molecular mechanism if consumed by normal population deliberately or inadvertently.

  18. Integrating informative priors from experimental research with Bayesian methods: an example from radiation epidemiology.

    Science.gov (United States)

    Hamra, Ghassan; Richardson, David; Maclehose, Richard; Wing, Steve

    2013-01-01

    Informative priors can be a useful tool for epidemiologists to handle problems of sparse data in regression modeling. It is sometimes the case that an investigator is studying a population exposed to two agents, X and Y, where Y is the agent of primary interest. Previous research may suggest that the exposures have different effects on the health outcome of interest, one being more harmful than the other. Such information may be derived from epidemiologic analyses; however, in the case where such evidence is unavailable, knowledge can be drawn from toxicologic studies or other experimental research. Unfortunately, using toxicologic findings to develop informative priors in epidemiologic analyses requires strong assumptions, with no established method for its utilization. We present a method to help bridge the gap between animal and cellular studies and epidemiologic research by specification of an order-constrained prior. We illustrate this approach using an example from radiation epidemiology.

  19. Experimental and theoretical analysis on the effect of inclination on metal powder sintered heat pipe radiator with natural convection cooling

    Science.gov (United States)

    Cong, Li; Qifei, Jian; Wu, Shifeng

    2017-02-01

    An experimental study and theoretical analysis of heat transfer performance of a sintered heat pipe radiator that implemented in a 50 L domestic semiconductor refrigerator have been conducted to examine the effect of inclination angle, combined with a minimum entropy generation analysis. The experiment results suggest that inclination angle has influences on both the evaporator and condenser section, and the performance of the heat pipe radiator is more sensitive to the inclination change in negative inclined than in positive inclined position. When the heat pipe radiator is in negative inclination angle position, large amplitude of variation on the thermal resistance of this heat pipe radiator is observed. As the thermal load is below 58.89 W, the influence of inclination angle on the overall thermal resistance is not that apparent as compared to the other three thermal loads. Thermal resistance of heat pipe radiator decreases by 82.86 % in inclination of 60° at the set of 138.46 W, compared to horizontal position. Based on the analysis results in this paper, in order to achieve a better heat transfer performance of the heat pipe radiator, it is recommended that the heat pipe radiator be mounted in positive inclination angle positions (30°-90°), where the condenser is above the evaporator.

  20. Radiation what it is, what you need to know

    CERN Document Server

    Gale, Robert Peter

    2013-01-01

    The essential guide to radiation: the good, the bad, and the utterly fascinating, explained with unprecedented clarity. Earth, born in a nuclear explosion, is a radioactive planet; without radiation, life would not exist. And while radiation can be dangerous, it is also deeply misunderstood and often mistakenly feared. Now Robert Peter Gale, M.D,—the doctor to whom concerned governments turned in the wake of the Chernobyl and Fukushima disasters—in collaboration with medical writer Eric Lax draws on an exceptional depth of knowledge to correct myths and establish facts. Exploring what have become trigger words for anxiety—nuclear energy and nuclear weapons, uranium, plutonium, iodine-131, mammogram, X-ray, CT scan, threats to the food chain—the authors demystify the science and dangers of radiation, and examine its myriad benefits, from safely sterilizing our food to the relatively low-risk fuel alternative of nuclear energy. This is the book for all readers who have asked themselves questions such...

  1. Cataract development in children with Coats disease: risk factors and outcome.

    Science.gov (United States)

    Daruich, Alejandra; Matet, Alexandre; Munier, Francis L

    2017-12-28

    To describe the clinical features of cataract during the course of Coats disease and to determine its risk factors and effects on the long-term visual outcome. The medical records of consecutive patients with Coats disease followed for at least 2 years were analyzed retrospectively. Ophthalmological examination, ancillary tests, and treatment modalities were reviewed. The time of cataract diagnosis and its management were recorded. Parameters influencing cataract development and final visual outcome were investigated using uni- and multivariate analysis. A total of 57 patients (mean age, 5.0 ± 4.0 years; 51 males) were included; cataract formation was observed in 16 (28%) during a mean follow-up of 7.1 ± 3.7 years. The mean time from diagnosis of Coats disease to cataract detection was 25 ± 22 months. Total white cataract developed in 12 patients (75%); posterior subcapsular cataract, in 4 (25%). Cataracts were surgically removed in 10 patients to improve fundus visualization and clinical follow-up. Presence of exudative retinal detachment at diagnosis was an independent risk factor for cataract formation (P = 0.031). Cataract development was associated with more advanced disease stages (P < 0.001). History of cataract was a significant predictor for worse final visual outcome (P < 0.001), independent of disease stage (P = 0.003) and presence of macular complication, such as atrophy, fibrosis, or tractional retinal detachment (P < 0.001, adjusted R 2 = 0.83). Cataract development is frequent in children with Coats disease and aggravates the visual prognosis. Exudative retinal detachment at diagnosis, present in more advanced disease stages, is an independent risk factor for cataract formation. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  2. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Energy Technology Data Exchange (ETDEWEB)

    Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna (Austria); Simon, Steven L [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Wojcik, Andrzej [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Cardis, Elisabeth [Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar) and CIBER Epidemiologia y Salud Publica - CIBERESP, Barcelona (Spain); Laurier, Dominique; Tirmarche, Margot [Radiobiology and Epidemiology Department, Radiological and Human Health Division, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses (France); Hayata, Isamu [National Institute of Radiological Sciences, Chiba (Japan)], E-mail: jhendry2002uk@yahoo.com

    2009-06-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of {sup 222}Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  3. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Science.gov (United States)

    Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

    2009-06-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of (222)Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  4. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Science.gov (United States)

    Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

    2014-01-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case–control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case–control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors. PMID:19454802

  5. Natural course of photic maculopathy secondary to uncomplicated cataract surgery.

    Science.gov (United States)

    Querques, Lea; Querques, Giuseppe; Cascavilla, Maria Lucia; Triolo, Giacinto; Lattanzio, Rosangela; Introini, Ugo; Bandello, Francesco

    2014-03-01

    We report on a 36-year-old man who developed photic maculopathy in the left eye shortly after uncomplicated cataract surgery. The visual acuity (VA) of the left eye was 6/39 and spectral domain optical coherence tomography (SD-OCT), performed one week after surgery, revealed a hyporeflective space in the outer retina (a 'partial-thickness hole') at the fovea. Microperimetry showed a relative central scotoma and multifocal electroretinogram (ERG) showed reduced responses within the central 10°. Two months later, VA in the felt eye improved to 6/6 and SD-OCT showed an almost complete resolution of the 'partial-thickness hole'. Microperimetry showed the resolution of the relative scotoma at the fovea and multifocal ERG showed improved responses within the central 10°. SD-OCT, microperimetry and multifocal ERG are useful tools in the diagnosis and follow-up of photic maculopathy after uncomplicated cataract surgery. Its natural history may be characterised by resolution of both morphological and functional changes shortly after surgery. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

  6. Cataract influence on iris recognition performance

    Science.gov (United States)

    Trokielewicz, Mateusz; Czajka, Adam; Maciejewicz, Piotr

    2014-11-01

    This paper presents the experimental study revealing weaker performance of the automatic iris recognition methods for cataract-affected eyes when compared to healthy eyes. There is little research on the topic, mostly incorporating scarce databases that are often deficient in images representing more than one illness. We built our own database, acquiring 1288 eye images of 37 patients of the Medical University of Warsaw. Those images represent several common ocular diseases, such as cataract, along with less ordinary conditions, such as iris pattern alterations derived from illness or eye trauma. Images were captured in near-infrared light (used in biometrics) and for selected cases also in visible light (used in ophthalmological diagnosis). Since cataract is a disorder that is most populated by samples in the database, in this paper we focus solely on this illness. To assess the extent of the performance deterioration we use three iris recognition methodologies (commercial and academic solutions) to calculate genuine match scores for healthy eyes and those influenced by cataract. Results show a significant degradation in iris recognition reliability manifesting by worsening the genuine scores in all three matchers used in this study (12% of genuine score increase for an academic matcher, up to 175% of genuine score increase obtained for an example commercial matcher). This increase in genuine scores affected the final false non-match rate in two matchers. To our best knowledge this is the only study of such kind that employs more than one iris matcher, and analyzes the iris image segmentation as a potential source of decreased reliability

  7. Radiative properties of scattering and absorbing dense media: theory and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Hespel, Laurent; Mainguy, Stephane; Greffet, J.-J

    2003-03-01

    We investigate the validity of the radiative transfer equation to model transmission of light through an absorbing and scattering medium. Assuming that radiative transfer equation is valid, the inverse scattering problem for non-polarized radiative transfer in one-dimensional absorbing and scattering media is solved using a parameter identification method. We discuss how to identify the albedo, phase function and extinction coefficient of the medium. We present experimental data that confirm that this approach is robust and can be used to make reliable predictions of the behavior of scattering absorbing systems.

  8. Clinical research on anterior chamber injection of dexamethasone after cataract surgery with uveitis

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2013-04-01

    Full Text Available AIM:To explore cataract surgery complication of the anterior chamber injection 0.1mL dexamethasone for uveitis complicated cataract patients. METHODS: The experimental group was injected 0.1mL dexamethasone to anterior chamber at the end of phacoemulsification(Phaco+intraocular lens(IOLimplantation, while the control group did not. And the different postoperative inflammation between them was observed. RESULTS: The differences of visual acuity between the two groups on the first two days after operation were statistically significant(P<0.05. The postoperative corneal edema and anterior chamber flare between the two groups in the first day were different(P<0.05. And the percentage of the experimental group postoperative visual acuity improved was higher than that of the control group. CONCLUSION: It can reduce short-term postoperative inflammation, improve visual acuity earlier and do not impact the short-term postoperative intraocular pressure that uveitis complicated cataract was injected 0.1mL dexamethasone to anterior chamber at the end of Phaco+IOL.

  9. Experimental design to understand the interaction of stellar radiation with molecular clouds

    Science.gov (United States)

    VanDervort, Robert; Davis, Josh; Trantham, Matt; Klein, Sallee; Frank, Yechiel; Raicher, Erez; Fraenkel, Moshe; Shvarts, Dov; Keiter, Paul; Drake, R. Paul

    2017-06-01

    Enhanced star formation triggered by local O and B type stars is an astrophysical problem of interest. O and B type stars are massive, hot stars that emit an enormous amount of radiation. This radiation acts to either compress or blow apart clumps of gas in the interstellar media. For example, in the optically thick limit, when the x-ray radiation in the gas clump has a short mean free path length the x-ray radiation is absorbed near the clump edge and compresses the clump. In the optically thin limit, when the mean free path is long, the radiation is absorbed throughout acting to heat the clump. This heating explodes the gas clump. Careful selection of parameters, such as foam density or source temperature, allow the experimental platform to access different hydrodynamic regimes. The stellar radiation source is mimicked by a laser irradiated thin gold foil. This will provide a source of thermal x-rays (around ~100 eV). The gas clump is mimicked by a low-density foam around 0.150 g/cc. Simulations were done using radiation hydrodynamics codes to tune the experimental parameters. The experiment will be carried out at the Omega laser facility on OMEGA 60.

  10. Microwave radiometry and its potential applications in biology and medicine: experimental studies.

    Science.gov (United States)

    Bigu-del-Blanco, J; Romero-Sierra, C; Watts, D G

    1975-01-01

    This paper presents experimental data on : (1) the natural emission of microwave radiation by biological systems, and (2) the effect of drugs as well as microwave radiation on specimen microwave emission. Experiments were conducted on guinea pigs, mice, rabbits, and human subjects. The results were obtained with two different radiometers, one of the correlation type and one of the Dicke type, operating in the X-band at about 9 GHz with a sensitivity of approximately 0.1 degrees K. The results demonstrate the feasibility of this technique and suggestions are made for its use in bilogy, medicine, and in the field of biocommunications.

  11. Experimental studies on coherent synchrotron radiation at an emittance exchange beam line

    Directory of Open Access Journals (Sweden)

    J. C. T. Thangaraj

    2012-11-01

    Full Text Available One of the goals of the Fermilab A0 photoinjector is to investigate experimentally the transverse to longitudinal emittance exchange (EEX principle. Coherent synchrotron radiation in the emittance exchange line could limit the performance of the emittance exchanger at short bunch lengths. In this paper, we present experimental and simulation studies of the coherent synchrotron radiation (CSR in the emittance exchange line at the A0 photoinjector. We report on time-resolved CSR studies using a skew-quadrupole technique. We also demonstrate the advantages of running the EEX with an energy-chirped beam.

  12. [Correlation between Alzheimer disease and cataract].

    Science.gov (United States)

    Liu, S S; Zhu, S Q

    2017-04-11

    Alzheimer disease (AD) is a progressive neurodegenerative disease and is a leading cause of dementia among elders. In the early phase of AD, even if neuropathological changes presented, but little to none clinical symptoms were found. Therefore, it is difficult to diagnose AD in the beginning of the disease. It is vital to find a noninvasive way for both diagnose and prognosis of AD. Studies have found that β-amyloid (Aβ) works as a connection between AD and cataract. This review will discuss AD and its associated markers which may be present in the lens and cataract related AD to provide more basis for early diagnosis of AD. (Chin J Ophthalmol, 2017, 53: 314-316).

  13. Radiation Damage in Nuclear Fuel for Advanced Burner Reactors: Modeling and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Niels Gronbech; Asta, Mark; Ozolins, Nigel Browning' Vidvuds; de Walle, Axel van; Wolverton, Christopher

    2011-12-29

    The consortium has completed its existence and we are here highlighting work and accomplishments. As outlined in the proposal, the objective of the work was to advance the theoretical understanding of advanced nuclear fuel materials (oxides) toward a comprehensive modeling strategy that incorporates the different relevant scales involved in radiation damage in oxide fuels. Approaching this we set out to investigate and develop a set of directions: 1) Fission fragment and ion trajectory studies through advanced molecular dynamics methods that allow for statistical multi-scale simulations. This work also includes an investigation of appropriate interatomic force fields useful for the energetic multi-scale phenomena of high energy collisions; 2) Studies of defect and gas bubble formation through electronic structure and Monte Carlo simulations; and 3) an experimental component for the characterization of materials such that comparisons can be obtained between theory and experiment.

  14. [Experimental and theoretical studies on radiation protective effect of a lighter non-lead protective apron].

    Science.gov (United States)

    Takano, Yoshihisa; Okazaki, Keiichiro; Ono, Koji; Kai, Michiaki

    2005-07-20

    Non-lead aprons using composite materials are often used for radiation protective aprons instead of heavy lead aprons. However, the protective effect of the lighter, non-lead aprons has not been well evaluated, and it is not yet clear how they compare with lead aprons. Therefore, we investigated the protective performance of non-lead aprons theoretically and experimentally by comparing them with lead aprons under clinical conditions. We measured the energy spectra for direct and scattered X-rays passing through protective aprons or not, and measured doses with glass dosimeters for validation of theoretical calculations based on the energy spectra. We found that the protective effect of non-lead aprons was higher than that of lead aprons at X-ray of tube voltages of 70-100 kV, which are often used for radiography and fluorography. This demonstrated that the non-lead aprons are more useful in many situations than heavy lead aprons.

  15. Experimental study of discharging PCM ceiling panels through nocturnal radiative cooling

    DEFF Research Database (Denmark)

    Bourdakis, Eleftherios; Péan, Thibault Q.; Gennari, Luca

    2016-01-01

    PhotoVoltaic/Thermal (PV/T) panels were used for cooling water through the principle of nocturnal radiative cooling. This water was utilised for discharging Phase Change Material (PCM) which was embedded in ceiling panels in a climate chamber. Three different sets of flow rates were examined...... for the solar and the PCM loops, for five days each. The highest examined water flow rate (210 l/h) in the PCM loop provided the best thermal environment in the climate chamber, namely 92% of the occupancy time was within the range of Category III of Standard EN 15251. Although the lowest examined water flow...... rate (96 l/h) in the solar loop provided the highest average cooling power, due to the significant variations in the weather conditions during the three experimental cases, made it impossible to determine to which extent the difference in the cooling power is due to the different water flow rate...

  16. Evaluation of anticataract potential of Triphala in selenite-induced cataract: In vitro and in vivo studies

    Directory of Open Access Journals (Sweden)

    Suresh Kumar Gupta

    2010-01-01

    Full Text Available Triphala (TP is composed of Emblica officinalis, Terminalia chebula, and Terminalia belerica. The present study was undertaken to evaluate its anticataract potential in vitro and in vivo in a selenite-induced experimental model of cataract. In vitro enucleated rat lenses were maintained in organ culture containing Dulbecco′s Modified Eagles Medium alone or with the addition of 100΅M selenite. These served as the normal and control groups, respectively. In the test group, the medium was supplemented with selenite and different concentrations of TP aqueous extract. The lenses were incubated for 24 h at 37°C. After incubation, the lenses were processed to estimate reduced glutathione (GSH, lipid peroxidation product, and antioxidant enzymes. In vivo selenite cataract was induced in 9-day-old rat pups by subcutaneous injection of sodium selenite (25 μmole/kg body weight. The test groups received 25, 50, and 75 mg/kg of TP intraperitoneally 4 h before the selenite challenge. At the end of the study period, the rats′ eyes were examined by slit-lamp. TP significantly (P < 0.01 restored GSH and decreased malondialdehyde levels. A significant restoration in the activities of antioxidant enzymes such as superoxide dismutase (P < 0.05, catalase (P < 0.05, glutathione peroxidase (P < 0.05, and glutathione-s-transferase (P < 0.005 was observed in the TP-supplemented group compared to controls. In vivo TF 25mg/kg developed only 20% nuclear cataract as compared to 100% in control. TP prevents or retards experimental selenite-induced cataract. This effect may be due to antioxidant activity. Further studies are warranted to explore its role in human cataract.

  17. N-acetylcarnosine (NAC) drops for age-related cataract.

    Science.gov (United States)

    Dubois, Vincent Dj-P; Bastawrous, Andrew

    2017-02-28

    Cataract is the leading cause of world blindness. The only available treatment for cataract is surgery. Surgery requires highly-trained individuals with expensive operating facilities. Where these are not available, patients go untreated. A form of treatment that did not involve surgery would be a useful alternative for people with symptomatic cataract who are unable or unwilling to undergo surgery. If an eye drop existed that could reverse or even prevent progression of cataract, then this would be a useful additional treatment option.Cataract tends to result from oxidative stress. The protein, L-carnosine, is known to have an antioxidant effect on the cataractous lens, so biochemically there is sound logic for exploring L-carnosine as an agent to reverse or even prevent progression of cataract. When applied as an eye drop, L-carnosine cannot penetrate the eye. However, when applied to the surface of the eye, N-acetylcarnosine (NAC) penetrates the cornea into the front chamber of the eye (near to where the cataract is), where it is metabolised into L-carnosine. Hence, it is possible that use of NAC eye drops may reverse or even prevent progression of cataract, thereby improving vision and quality of life. To assess the effectiveness of NAC drops to prevent or reverse the progression of cataract. We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2016), Embase (January 1980 to June 2016), Allied and Complementary Medicine Database (AMED) (January 1985 to June 2016), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to June 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use

  18. Study on biological response to space radiation and its countermeasure

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong Il; Lee, Ju Woon; Kim, Dong Ho; Kim, Jae Hun; Song, Beom Suk; Kim, Jae Kyung; Park, Jong Heum; Kim, Jin Kyu [KAERI, Daejeon (Korea, Republic of)

    2011-12-15

    The purpose is to develop the core technologies for the advanced life supporting system based on radiation technology by 2015 and to be a member of G7 in the space technology research field. And it is the final aim that contribution for establishment of the self-supporting technology and national strength by 2020. To simulate the space environment of microgravity and expose to space radiation, denervation model was established in Gamma Phytotron. The changes in microflora population in animal model was shown. The effect of simulated microgravity and long-term exposure to irradiation was investigated. In the experiment of MARS 500, crews for expedition to Mars had been served by Korean space foods (Bulgogi, Bibimbap, Seaweed soup, Mulberry beverage, Kimchi, Sujeonggwa) for 120 days, then their immunity will be examined and compared with it on the ground.

  19. Managing residual refractive error after cataract surgery.

    Science.gov (United States)

    Sáles, Christopher S; Manche, Edward E

    2015-06-01

    We present a review of keratorefractive and intraocular approaches to managing residual astigmatic and spherical refractive error after cataract surgery, including laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), arcuate keratotomy, intraocular lens (IOL) exchange, piggyback IOLs, and light-adjustable IOLs. Currently available literature suggests that laser vision correction, whether LASIK or PRK, yields more effective and predictable outcomes than intraocular surgery. Piggyback IOLs with a rounded-edge profile implanted in the sulcus may be superior to IOL exchange, but both options present potential risks that likely outweigh the refractive benefits except in cases with large residual spherical errors. The light-adjustable IOL may provide an ideal treatment to pseudophakic ametropia by obviating the need for secondary invasive procedures after cataract surgery, but it is not widely available nor has it been sufficiently studied. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  20. [Radiation protection in interventional radiology].

    Science.gov (United States)

    Adamus, R; Loose, R; Wucherer, M; Uder, M; Galster, M

    2016-03-01

    The application of ionizing radiation in medicine seems to be a safe procedure for patients as well as for occupational exposition to personnel. The developments in interventional radiology with fluoroscopy and dose-intensive interventions require intensified radiation protection. It is recommended that all available tools should be used for this purpose. Besides the options for instruments, x‑ray protection at the intervention table must be intensively practiced with lead aprons and mounted lead glass. A special focus on eye protection to prevent cataracts is also recommended. The development of cataracts might no longer be deterministic, as confirmed by new data; therefore, the International Commission on Radiological Protection (ICRP) has lowered the threshold dose value for eyes from 150 mSv/year to 20 mSv/year. Measurements show that the new values can be achieved by applying all X‑ray protection measures plus lead-containing eyeglasses.

  1. Experimental observation and investigation of the prewave zone effect in optical diffraction radiation

    Directory of Open Access Journals (Sweden)

    P. Karataev

    2008-03-01

    Full Text Available Transition radiation (TR and diffraction radiation (DR has widely been used for both electron beam diagnostics and generation of intense radiation beams in the millimeter and the submillimeter wavelength range. Recently, it was theoretically predicted that TR and DR properties change either at extremely high energies of electrons or at long radiation wavelengths. This phenomenon was called a prewave zone effect. We have performed the first observation and detailed investigation of the prewave zone effect in optical diffraction radiation at 1.28 GeV electron beam at the KEK-Accelerator Test Facility (KEK-ATF. The beam energy at KEK-ATF is definitely not the highest one achieved in the world. Since we could easily observe the effect, at higher energies it might cause serious problems. We developed and applied a method for prewave zone suppression valid for optical wavelengths. Furthermore, a method for prewave zone suppression applicable for longer radiation wavelengths is discussed.

  2. Radiative cooling of H3O+ and its deuterated isotopologues

    CERN Document Server

    Melnikov, Vladlen V; Tennyson, Jonathan; Jensen, Per

    2016-01-01

    In conjunction with ab initio potential energy and dipole moment surfaces for the electronic ground state, we have made a theoretical study of the radiative lifetimes for the hydronium ion H$_3$O$^{+}$ and its deuterated isotopologues. We compute the ro-vibrational energy levels and their associated wavefunctions together with Einstein coefficients for the electric dipole transitions. A detailed analysis of the stability of the ro-vibrational states have been carried out and the longest-living states of the hydronium ions have been identified. We report estimated radiative lifetimes and cooling functions for temperatures $<$ 200 K. A number of long-living meta-stable states are identified, capable of population trapping.

  3. Experimental verification of theoretical equations for acoustic radiation force on compressible spherical particles in traveling waves

    Science.gov (United States)

    Johnson, Kennita A.; Vormohr, Hannah R.; Doinikov, Alexander A.; Bouakaz, Ayache; Shields, C. Wyatt; López, Gabriel P.; Dayton, Paul A.

    2016-05-01

    Acoustophoresis uses acoustic radiation force to remotely manipulate particles suspended in a host fluid for many scientific, technological, and medical applications, such as acoustic levitation, acoustic coagulation, contrast ultrasound imaging, ultrasound-assisted drug delivery, etc. To estimate the magnitude of acoustic radiation forces, equations derived for an inviscid host fluid are commonly used. However, there are theoretical predictions that, in the case of a traveling wave, viscous effects can dramatically change the magnitude of acoustic radiation forces, which make the equations obtained for an inviscid host fluid invalid for proper estimation of acoustic radiation forces. To date, experimental verification of these predictions has not been published. Experimental measurements of viscous effects on acoustic radiation forces in a traveling wave were conducted using a confocal optical and acoustic system and values were compared with available theories. Our results show that, even in a low-viscosity fluid such as water, the magnitude of acoustic radiation forces is increased manyfold by viscous effects in comparison with what follows from the equations derived for an inviscid fluid.

  4. Cataract phacoemulsification and corneal endothelial cell damage

    Directory of Open Access Journals (Sweden)

    Ni Zhu

    2013-07-01

    Full Text Available Phacoemulsification with small incision, reduced number of inflammation cells, and better postoperative recovery has been recognized as the world's most popular option for cataract surgery. Modern cataract surgery is developing gradually from sight rehabilitating to refractive surgery with better vision acuity. Being the most important part of the eye refractive system, maintenance of the cornea's transparency relies heavily upon the healthy endothelial cells. It is well known that there will be endothelial cell loss after phacoemulsification and the damage of the endothelial cells may lead to corneal swellings and opacity, or even the corneal descompensation, which often severely influenced the postoperative vision recovery. This is a review of phacoemulsification and the risk factors of corneal endothelial damage pre-and postoperation.

  5. Maximal mydriasis evaluation in cataract surgery

    Directory of Open Access Journals (Sweden)

    Ho Tony

    1992-01-01

    Full Text Available We propose the Maximal Mydriasis Test (MMT as a simple and safe means to provide the cataract surgeon with objective and dependable pre-operative information on the idiosyncratic mydriatic response of the pupil. The MMT results of a consecutive series of 165 eyes from 100 adults referred for cataract evaluation are presented to illustrate its practical applications and value. The results of the MMT allows the surgeon to anticipate problem eyes pre-operatively so that he can plan his surgical strategy more appropriately and effectively. Conversely, the surgeon can also appropriately and confidently plan surgical procedures where wide pupillary dilation is important. The MMT has also helped improve our cost-effectiveness by cutting down unnecessary delays in the operating room and enabling better utilisation of restricted costly resources.

  6. Experimental investigations of synchrotron radiation at the onset of the quantum regime

    DEFF Research Database (Denmark)

    Andersen, Kristoffer; Uggerhøj, Ulrik Ingerslev

    the magnetic field is comparable to the critical field, quantum corrections are essential for the description of synchrotron radiation to conserve energy. With electrons of energies 10-150 GeV penetrating a germanium single crystal along the axis, we have experimentally investigated the transition from......The classical description of synchrotron radiation fails at large Lorentz factors for relativistic electrons crossing strong transverse magnetic fields. In the rest frame of the electron this field is comparable to the so-called critical field of 4.414*109 T. When the Lorentz factor times...... the regime where classical synchrotron radiation is an adequate description, to the regime where the emission drastically changes character; not only in magnitude, but also in spectral shape. The spectrum can only be described by quantum synchrotron radiation formulas. Apart from being a test of strong...

  7. Experimental investigations of synchrotron radiation at the onset of the quantum regime

    DEFF Research Database (Denmark)

    Andersen, Kristoffer; Knudsen, Helge; Uggerhøj, Ulrik Ingerslev

    2012-01-01

    = \\gamma B/B_0 \\simeq 1$ quantum corrections are essential for the description of synchrotron radiation to conserve energy. With electrons of energies 10-150 GeV penetrating a germanium single crystal along the $\\langle110\\rangle$ axis, we have experimentally investigated the transition from the regime......The classical description of synchrotron radiation fails at large Lorentz factors, $\\gamma$, for relativistic electrons crossing strong transverse magnetic fields $B$. In the rest frame of the electron this field is comparable to the so-called critical field $B_0 = 4.414\\cdot10^9$ T. For $\\chi...... where classical synchrotron radiation is an adequate description, to the regime where the emission drastically changes character; not only in magnitude, but also in spectral shape. The spectrum can only be described by quantum synchrotron radiation formulas. Apart from being a test of strong...

  8. Numerical simulation and experimental research of the integrated high-power LED radiator

    Science.gov (United States)

    Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

    2017-01-01

    The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

  9. Experimental Verification of Isotropic Radiation from a Coherent Dipole Source via Electric-Field-Driven LC Resonator Metamaterials

    Science.gov (United States)

    Tichit, Paul-Henri; Burokur, Shah Nawaz; Qiu, Cheng-Wei; de Lustrac, André

    2013-09-01

    It has long been conjectured that isotropic radiation by a simple coherent source is impossible due to changes in polarization. Though hypothetical, the isotropic source is usually taken as the reference for determining a radiator’s gain and directivity. Here, we demonstrate both theoretically and experimentally that an isotropic radiator can be made of a simple and finite source surrounded by electric-field-driven LC resonator metamaterials designed by space manipulation. As a proof-of-concept demonstration, we show the first isotropic source with omnidirectional radiation from a dipole source (applicable to all distributed sources), which can open up several possibilities in axion electrodynamics, optical illusion, novel transformation-optic devices, wireless communication, and antenna engineering. Owing to the electric- field-driven LC resonator realization scheme, this principle can be readily applied to higher frequency regimes where magnetism is usually not present.

  10. Experimental social innovation and dissemination: the promise and its delivery.

    Science.gov (United States)

    Hazel, Kelly L; Onaga, Esther

    2003-12-01

    This paper describes the origin of the Experimental Social Innovation and Dissemination model and its contribution to and intersection with community psychology. It also discusses the challenges presented to ESID by community psychology's growing emphasis on cultural diversity and participatory approaches to research and intervention. It concludes with an overview of the papers presented in the special issue.

  11. Explicit criteria for prioritization of cataract surgery

    Directory of Open Access Journals (Sweden)

    Escobar Antonio

    2006-03-01

    Full Text Available Abstract Background Consensus techniques have been used previously to create explicit criteria to prioritize cataract extraction; however, the appropriateness of the intervention was not included explicitly in previous studies. We developed a prioritization tool for cataract extraction according to the RAND method. Methods Criteria were developed using a modified Delphi panel judgment process. A panel of 11 ophthalmologists was assembled. Ratings were analyzed regarding the level of agreement among panelists. We studied the effect of all variables on the final panel score using general linear and logistic regression models. Priority scoring systems were developed by means of optimal scaling and general linear models. The explicit criteria developed were summarized by means of regression tree analysis. Results Eight variables were considered to create the indications. Of the 310 indications that the panel evaluated, 22.6% were considered high priority, 52.3% intermediate priority, and 25.2% low priority. Agreement was reached for 31.9% of the indications and disagreement for 0.3%. Logistic regression and general linear models showed that the preoperative visual acuity of the cataractous eye, visual function, and anticipated visual acuity postoperatively were the most influential variables. Alternative and simple scoring systems were obtained by optimal scaling and general linear models where the previous variables were also the most important. The decision tree also shows the importance of the previous variables and the appropriateness of the intervention. Conclusion Our results showed acceptable validity as an evaluation and management tool for prioritizing cataract extraction. It also provides easy algorithms for use in clinical practice.

  12. [Development of a monitor for quantifying personal eye exposure to visible and ultraviolet radiation and its application in epidemiology].

    Science.gov (United States)

    Eto, Norihito; Tsubota, Kazuo; Tanaka, Taichiro; Nishiwaki, Yuji

    2013-01-01

    Eye diseases including cataract, keratitis and pterygium have been reported to be sun-exposure-related. The association between macular degeneration and blue light has also been discussed. Moreover, it is hypothesized that retinal exposure to blue light may influence the human circadian rhythm. However, no monitoring devices exist that can measure eye exposure to visible and ultraviolet (UV) radiation over time. To measure the exact dose at specific times, we have developed a novel sensing system (ray-sensing glass system: RaySeG). RaySeG can continuously measure and record the composition and intensity of light with a time-stamped system. Subjects wearing RaySeG were instructed to walk under various light conditions such as indoor and outdoor. RaySeG consists of two sensors embedded in the eyeglasses. These sensors are for UV (260-400 nm), visible lights (red, 615 nm; green, 540 nm; and blue, 465 nm: peak wavelength for each). The total weight of the system is about 100 g, and the size is comparable to that of a digital audio player. The system continuously recorded changes in visible and UV light exposure under various conditions. After accuracy validation, further experiments with a larger number of subjects are required. Our final goal is to apply the system to evaluating personal eye exposure to UV and visible light in epidemiological studies of eye diseases and circadian rhythm abnormality.

  13. Cataract surgery after pars plana vitrectomy.

    Science.gov (United States)

    Shousha, Mohamed Abou; Yoo, Sonia H

    2010-01-01

    To review recent studies and advances and their possible implications in the care of patients undergoing cataract surgery after pars plana vitrectomy. Optical biometry has shown to be superior to ultrasound biometry in vitrectomized eyes but still not achieving as good results as it does in nonvitrectomized eyes. Blue light-filter intraocular lenses, with their possible advantage of macular protection, have shown no operative or functional disadvantages in vitrectomized eyes, and thus their routine use can be justified. However, presbyopia-correcting intraocular lenses, at least at their current stage of development, generally, are still not accepted for vitrectomized eyes. Combining cataract surgery with intravitreal injections of bevacizumab or triamcinolone acetonide in patients with macular edema and cataract is advisable to avoid exacerbation of the condition and improve visual outcome. Despite the recent advances, incidences of posterior capsular opacification and retinal detachment are still considerable. Understanding ocular anatomical alterations imposed by the previous pars plana vitrectomy surgery and the underlying vitreoretinal disease will allow the surgeon to address the special challenges. Despite that, recent advances in techniques and instrumentation have improved the surgical safety and outcomes, reported complications rates are still relatively high.

  14. Does Less Invasive Spine Surgery Result in Increased Radiation Exposure? A Systematic Review

    National Research Council Canada - National Science Library

    Yu, Elizabeth; Khan, Safdar N

    2014-01-01

    .... The risks of radiation exposure include thyroid cancer, cataracts, and lymphoma. Although imaging techniques facilitate less invasive approaches and improve intraoperative accuracy, they may increase radiation...

  15. Diet, vegetarianism, and cataract risk.

    Science.gov (United States)

    Appleby, Paul N; Allen, Naomi E; Key, Timothy J

    2011-05-01

    Age-related cataract is a major cause of morbidity. Previous studies of diet and cataract risk have focused on specific nutrients or healthy eating indexes but not on identifiable dietary groups such as vegetarians. We investigated the association between diet and cataract risk in a population that has a wide range of diets and includes a high proportion of vegetarians. We used Cox proportional hazards regression to study cataract risk in relation to baseline dietary and lifestyle characteristics of 27,670 self-reported nondiabetic participants aged ≥40 y at recruitment in the Oxford (United Kingdom) arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford) by using data from the Hospital Episode Statistics in England and Scottish Morbidity Records. There was a strong relation between cataract risk and diet group, with a progressive decrease in risk of cataract in high meat eaters to low meat eaters, fish eaters (participants who ate fish but not meat), vegetarians, and vegans. After multivariable adjustment, incidence rate ratios (95% CIs) for moderate meat eaters (50-99 g meat/d), low meat eaters (vegetarians, and vegans compared with high-meat eaters (≥100 g meat/d) were 0.96 (0.84, 1.11), 0.85 (0.72, 0.99), 0.79 (0.65, 0.97), 0.70 (0.58, 0.84), and 0.60 (0.38, 0.96), respectively (P Vegetarians were at lower risk of cataract than were meat eaters in this cohort of health-conscious British residents.

  16. [Evaluation of corneal endothelium following cataract surgery in diabetic patients].

    Science.gov (United States)

    Langwińska-Wośko, Ewa; Chociszewska-Nitka, Anna; Zielińska, Edyta; Hapunik, Adam

    2004-01-01

    The aim of this study was to evaluate the influence of cataract surgery on the condition of corneal endothelium, in diabetic patients. We examined 103 patients (103 eyes) after cataract surgery (64 women and 39 men), at the age between 49 and 89. In our study we didn't involve any patients with intra or post-surgery complications. Using Specular Microscope SP-1000 corneal endothelium was examined before cataract surgery and in the long-term follow-up: 7, 30 and 90 days after surgery. The patients were divided into two groups: suffering from diabetes (54) and matched control group--non-diabetic patients with cataract (49). The same patients were also divided depending on the type of surgical technique: phacoemulsification (42) or extracapsular cataract extraction (61). The mean percent loss of corneal endothelium cells, due to surgery in diabetic patients was: 11.31% after 7 days, 13.99% after 30 and 15.38% after 90 days. In the control group: 5.45% after 7 days, 8.66% after 30 and 11.33% after 90 days. The mean percent loss of corneal endothelium cells after phacoemulsification was: 10.10% after 7 days, 13.21% after 30 and 15.87% after 90 days; after extra-capsular cataract extraction: 6.84% after 7 days, 9.71% after 30 and 11.48% after 90 days. Differences between mean value of corneal endothelial cells in diabetic patients compared with control group, were statistically essential 7 and 30 days after cataract surgery, and near such assessment 90 days after surgery. There were no statistically essential differences between endothelial cells density in both operated groups, in relation to type of operation (phacoemulsification and extra-capsular cataract extraction). Above results are the evidence, that cataract surgery is a big trauma for cornea, especially for its endothelium. The operation is mainly dangerous for patients suffering from diabetes. The surgeon should be aware of the above threat during cataract surgery in diabetic patients, and therefore should

  17. Occupational cataracts and lens opacities in interventional cardiology (O'CLOC study: are X-Rays involved?

    Directory of Open Access Journals (Sweden)

    Jacob Sophie

    2010-09-01

    Full Text Available Abstract Background The eye is well known to be sensitive to clearly high doses (>2 Gy of ionizing radiation. In recent years, however, cataracts have been observed in populations exposed to lower doses. Interventional cardiologists are repeatedly and acutely exposed to scattered ionizing radiation (X-rays during the diagnostic and therapeutic procedures they perform. These "low" exposures may cause damage to the lens of the eye and induce early cataracts, known as radiation-induced cataracts. The O'CLOC study (Occupational Cataracts and Lens Opacities in interventional Cardiology was designed to test the hypothesis that interventional cardiologists, compared with an unexposed reference group of non-interventional cardiologists, have an increased risk of cataracts. Method/Design The O'CLOC study is a cross-sectional study that will include a total of 300 cardiologists aged at least 40 years: one group of exposed interventional cardiologists and another of non-interventional cardiologists. The groups will be matched for age and sex. Individual information, including risk factors for cataracts (age, diabetes, myopia, etc., will be collected during a telephone interview. A specific section of the questionnaire for the exposed group focuses on occupational history, including a description of the procedures (type, frequency, radiation protection tool used. These data will be used to classify subjects into "exposure level" groups according to cumulative dose estimates. Eye examinations for all participants will be performed to detect cataracts, even in the early stages (lens opacities, according to LOCS III, the international standard classification. The analysis will provide an estimation of the cataract risk in interventional cardiology compared with the unexposed reference group, while taking other risk factors into account. An analysis comparing the risks according to level of exposure is also planned. Discussion This epidemiological study will

  18. Inspection of cardiology departments in Norway: are they making it great in radiation protection?

    Science.gov (United States)

    Silkoset, R D; Widmark, A; Friberg, E G

    2015-07-01

    Staff involved in interventional cardiology receive the highest occupational doses in Norway, and skin burns of patients have been reported. To identify the level of radiation protection (RP) for patients and staff, and compliance with the RP regulation, the Norwegian Radiation Protection Authority carried out inspections. The inspections were conducted (2013-14) as quality system reviews, based on document reviews, interviews, on-site inspections and observations of interventional procedures. The inspections revealed that most of the hospitals had non-compliances according to the RP regulation. Most deviations were associated with education in RP and follow-up of patients who had received high radiation doses. Lack of systematic optimisation of procedures and estimation of eye lens doses to evaluate the risk for cataracts were also common. Inspections turned out to increase the awareness of RP in cardiology and are identified as an effective tool for improving RP. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Radiation and Its Health Effects. AIO Red Paper #19.

    Science.gov (United States)

    Duda, Terrie

    Radiation has been a serious concern to individuals for over 100 years. A process by which an atomic nucleus emits particles to reach a more stable energy state, radiation harms living cells (usually by inhalation and absorption into the lungs) by causing abnormal cell function and structure. Man is constantly exposed to background radiation, both…

  20. Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

    KAUST Repository

    Garcia-Corral, Lara S.

    2015-07-07

    The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A) may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota. Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP) of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3°C), alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced NCP and resulted in a heterotrophic (NCP < 0) metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV × Temp) was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2−O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle.

  1. Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

    Directory of Open Access Journals (Sweden)

    Lara S. eGarcia-Corral

    2015-07-01

    Full Text Available The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota.Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3ºC, alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced net community production and resulted in a heterotrophic (NCP<0 metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV x Temp was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2-O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle

  2. Antioxidative activities of 4-hydroxy-3(2H)-furanones and their anti-cataract effect on spontaneous cataract rat (ICR/f).

    Science.gov (United States)

    Sasaki, T; Yamakoshi, J; Saito, M; Kasai, K; Matsudo, T; Koga, T; Mori, K

    1998-10-01

    We determined the anti-cataract effects and antioxidative activities of four 4-hydroxy-3(2H)-furanones. These four furanones showed similar antioxidative activities in the ferric ion reduction model. 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) and 2(or 5)-ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone (EHMF) exhibited a higher suppression effect on lipid peroxidation in human plasma than the other furanones did. The effects of hydroxy furanones on the onset of cataract in spontaneous cataract rat (ICR/f rat) were tested, and it was observed that HDMF and EHMF inhibited cataract formation. These results suggest that the antioxidative activity of HDMF and EHMF against superoxide radicals in lens tissue contributed to inhibiting the onset of spontaneous cataract.

  3. Cataract Surgery in the Glaucoma Patient

    Science.gov (United States)

    Kung, Jennifer S.; Choi, Daniel Y.; Cheema, Anjum S.; Singh, Kuldev

    2015-01-01

    To summarize the role of cataract surgery in the glaucoma patient, in terms of the effect on intraocular pressure (IOP) as well as diagnostic and therapeutic considerations for those with both conditions. Recent evidence suggests that cataract extraction may produce a significant and sustained IOP reduction in individuals with open-angle glaucoma, ocular hypertension, and angle-closure glaucoma. Cataract removal may improve the practitioner's ability to interpret perimetric testing, and re-establishing perimetric and optic nerve imaging baselines is recommended after cataract surgery. The sequence of cataract surgery relative to glaucoma surgery impacts the likelihood of complications and surgical success. There are multiple benefits to perform cataract surgery prior to glaucoma surgery while cataract surgery after trabeculectomy increases the risk of subsequent filtration failure. As “minimally invasive glaucoma surgeries” continue to improve in terms of efficacy, there is an evolving role for combined cataract and glaucoma surgery in patients with early to moderate stages of glaucoma. PMID:25624668

  4. Auditory brainstem response changes during exposure to GSM-900 radiation: an experimental study.

    Science.gov (United States)

    Kaprana, Antigoni E; Chimona, Theognosia S; Papadakis, Chariton E; Velegrakis, Stylianos G; Vardiambasis, Ioannis O; Adamidis, Georgios; Velegrakis, George A

    2011-01-01

    The objective of the present study was to investigate the possible electrophysiological time-related changes in auditory pathway during mobile phone electromagnetic field exposure. Thirty healthy rabbits were enrolled in an experimental study of exposure to GSM-900 radiation for 60 min and auditory brainstem responses (ABRs) were recorded at regular time-intervals during exposure. The study subjects were radiated via an adjustable power and frequency radio transmitter for GSM-900 mobile phone emission simulation, designed and manufactured according to the needs of the experiment. The mean absolute latency of waves III-V showed a statistically significant delay (p < 0.05) after 60, 45 and 15 min of exposure to electromagnetic radiation of 900 MHz, respectively. Interwave latency I-III was found to be prolonged after 60 min of radiation exposure in correspondence to wave III absolute latency delay. Interwave latencies I-V and III-V were found with a statistically significant delay (p < 0.05) after 30 min of radiation. No statistically significant delay was found for the same ABR parameters in recordings from the ear contralateral to the radiation source at 60 min radiation exposure compared with baseline ABR. The ABR measurements returned to baseline recordings 24 h after the exposure to electromagnetic radiation of 900 MHz. The prolongation of interval latencies I-V and III-V indicates that exposure to electromagnetic fields emitted by mobile phone can affect the normal electrophysiological activity of the auditory system, and these findings fit the pattern of general responses to a stressor. Copyright © 2010 S. Karger AG, Basel.

  5. Advances in hard nucleus cataract surgery

    Directory of Open Access Journals (Sweden)

    Wei Cui

    2013-11-01

    Full Text Available Security and perfect vision and fewer complications are our goals in cataract surgery, and hard-nucleus cataract surgery is always a difficulty one. Many new studies indicate that micro-incision phacoemulsification in treating hard nucleus cataract is obviously effective. This article reviews the evolution process of hard nuclear cataract surgery, the new progress in the research of artificial intraocular lens for microincision, and analyse advantages and disadvantages of various surgical methods.

  6. Blindness, cataract surgery and mortality in Ethiopia.

    Science.gov (United States)

    Thomas, Benjamin J; Sanders, David S; Oliva, Matthew S; Orrs, Mark S; Glick, Peter; Ruit, Sanduk; Chen, Wei; Luoto, Jill; Tasfaw, Alemu Kerie; Tabin, Geoffrey C

    2016-09-01

    To examine the relationships between blindness, the intervention of cataract surgery and all-cause mortality in a rural Ethiopian population. Population-based, interventional prospective study. Community-based detection methods identified blind Ethiopian persons from two selected kebeles in Amhara region, Ethiopia. Data from 1201 blind patients were collected-628 cataract-blind and 573 blind from other conditions. Free cataract surgery was provided for consenting, cataract-blind patients. Follow-up surveys were conducted after 12 months (±1 month)-the main outcome measure for this report is all-cause mortality at 1 year. During the follow-up period, 110 persons died from the selected population (mortality 9.2%), which consisted of those cataract-blind patients who received cataract surgery (N=461), cataract-blind patients who did not receive surgery (N=167) and all non-cataract-blind patients (N=573). Of the 461 patients who received cataract surgery, 44 patients died (9.5%). Of the 740 patients who did not receive surgery, 66 died (8.9%)-28 patients from the cohort of cataract-blind patients who did not receive surgery (16.8%) and 38 patients from the cohort of non-cataract blind (6.6%). Subgroup analysis revealed significantly increased odds of mortality for cataract-blind patients over 75 years of age who did not receive surgery and for unmarried patients of all age groups. In this population, mortality risk was significantly elevated for older cataract-blind patients when compared with non-cataract-blind patients-an elevation of risk that was not noted in an age-matched cohort of cataract-blind patients who underwent cataract surgery as early as 1-year follow-up. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Radon Release and Its Simulated Effect on Radiation Doses.

    Science.gov (United States)

    Orabi, Momen

    2017-03-01

    One of the main factors that affect the uncertainty in calculating the gamma-radiation absorbed dose rate inside a room is the variation in the degree of secular equilibrium of the considered radioactive series. A component of this factor, considered in this paper, is the release of radon (Rn) from building materials to the living space of the room. This release takes place through different steps. These steps are represented and mathematically formulated. The diffusion of radon inside the material is described by Fick's second law. Some of the factors affecting the radon release rate (e.g. covering walls, moisture, structure of the building materials, etc.) are discussed. This scheme is used to study the impact of radon release on the gamma-radiation absorbed dose rate inside a room. The investigation is carried out by exploiting the MCNP simulation software. Different building materials are considered with different radon release rates. Special care is given to Rn due to its relatively higher half-life and higher indoor concentration than the other radon isotopes. The results of the presented model show that the radon release is of a significant impact in some building materials.

  8. Cataract surgery output and cost of hospitalization for cataract ...

    African Journals Online (AJOL)

    La cataracte avait la fréquence la plus élevée comme a cause de la cécité guérissable au Nigéria. Approximativement, le total de la population nigériane est 110 million et le taux de la fréquence de la cécité est 1%. La cataracte est la cause principale de 30 à 60% cas des cécité. Si nous devons réussir à éliminer les arrièrs ...

  9. Design of organic scintillators for non-standard radiation field dosimetry: experimental setup.

    Science.gov (United States)

    Norman H, Machado R; Maximiliano, Trujillo T; Javier E, García G; Diana C, Narvaez G; Paula A, Marín M; Róbinson A, Torres V

    2013-01-01

    This paper describes an experimental setup designed for sensing the luminescent light coming from an organic plastic scintillator stimulated with ionizing radiation. This device is intended to be a part of a complete dosimeter system for characterization of small radiation fields which is the project of the doctoral thesis of the medical physicist at the Radiation Oncology facility of Hospital San Vicente Fundación in conjunction with the Universidad de Antioquia of Medellín Colombia. Some preliminary results predict a good performance of the unit, but further studies must be conducted in order to have a completed evaluation of the system. This is the first step in the development of an accuracy tool for measurement of non-standard fields in the Radiotherapy or Radiosurgery processes.

  10. Impacts of radiation exposure on the experimental microbial ecosystem: a particle-based model simulation approach

    Energy Technology Data Exchange (ETDEWEB)

    Doi, M.; Tanaka, N.; Fuma, S.; Kawabata, Z.

    2004-07-01

    Well-designed experimental model ecosystem could be a simple reference of the actual environment and complex ecological systems. For ecological toxicity test of radiation and other environmental toxicants, we investigated and aquatic microbial ecosystem (closed microcosm) in the test tube with initial substrates,autotroph flagellate algae (Euglena, G.), heterotroph ciliate protozoa (Tetrahymena T.) and saprotroph bacteria (E, coli). These species organizes by itself to construct the ecological system, that keeps the sustainable population dynamics for more than 2 years after inoculation only by adding light diurnally and controlling temperature at 25 degree Celsius. Objective of the study is to develop the particle-based computer simulation by reviewing interactions among microbes and environment, and analyze the ecological toxicities of radiation on the microcosm by replicating experimental results in the computer simulation. (Author) 14 refs.

  11. Determination of Radiative Heat Transfer Coefficient at High Temperatures Using a Combined Experimental-Computational Technique

    Science.gov (United States)

    Kočí, Václav; Kočí, Jan; Korecký, Tomáš; Maděra, Jiří; Černý, Robert Č.

    2015-04-01

    The radiative heat transfer coefficient at high temperatures is determined using a combination of experimental measurement and computational modeling. In the experimental part, cement mortar specimen is heated in a laboratory furnace to 600°C and the temperature field inside is recorded using built-in K-type thermocouples connected to a data logger. The measured temperatures are then used as input parameters in the three dimensional computational modeling whose objective is to find the best correlation between the measured and calculated data via four free parameters, namely the thermal conductivity of the specimen, effective thermal conductivity of thermal insulation, and heat transfer coefficients at normal and high temperatures. The optimization procedure which is performed using the genetic algorithms provides the value of the high-temperature radiative heat transfer coefficient of 3.64 W/(m2K).

  12. Experimental investigations of synchrotron radiation at the onset of the quantum regime

    CERN Document Server

    Andersen, Kristoffer K; Knudsen, H; Thomsen, H D; Uggerhøj, U I; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Ballestrero, S

    2012-01-01

    The classical description of synchrotron radiation fails at large Lorentz factors, $\\gamma$, for relativistic electrons crossing strong transverse magnetic fields $B$. In the rest frame of the electron this field is comparable to the so-called critical field $B_0 = 4.414\\cdot10^9$ T. For $\\chi = \\gamma B/B_0 \\simeq 1$ quantum corrections are essential for the description of synchrotron radiation to conserve energy. With electrons of energies 10-150 GeV penetrating a germanium single crystal along the $$ axis, we have experimentally investigated the transition from the regime where classical synchrotron radiation is an adequate description, to the regime where the emission drastically changes character; not only in magnitude, but also in spectral shape. The spectrum can only be described by quantum synchrotron radiation formulas. Apart from being a test of strong-field quantum electrodynamics, the experimental results are also relevant for the design of future linear colliders where beamstrahlung - a closely r...

  13. Immediate Sequential Bilateral Cataract Surgery

    DEFF Research Database (Denmark)

    Kessel, Line; Andresen, Jens; Erngaard, Ditte

    2015-01-01

    The aim of the present systematic review was to examine the benefits and harms associated with immediate sequential bilateral cataract surgery (ISBCS) with specific emphasis on the rate of complications, postoperative anisometropia, and subjective visual function in order to formulate evidence......-based national Danish guidelines for cataract surgery. A systematic literature review in PubMed, Embase, and Cochrane central databases identified three randomized controlled trials that compared outcome in patients randomized to ISBCS or bilateral cataract surgery on two different dates. Meta-analyses were...... performed using the Cochrane Review Manager software. The quality of the evidence was assessed using the GRADE method (Grading of Recommendation, Assessment, Development, and Evaluation). We did not find any difference in the risk of complications or visual outcome in patients randomized to ISBCS or surgery...

  14. Self-experimentation and its role in medical research.

    Science.gov (United States)

    Weisse, Allen B

    2012-01-01

    Although experimentation involving human volunteers has attracted intense study, the matter of self-experimentation among medical researchers has received much less attention. Many questions have been answered only in part, or have been left unanswered. How common is this practice? Is it more common among certain nationalities? What have been the predominant medical fields in which self-experimentation has occurred? How dangerous an act has this proved to be? What have been the trends over time? What is the future likely to bring?From the available literature, I identified and analyzed 465 documented instances of this practice, performed over the course of the past 2 centuries. Most instances occurred in the United States. The peak of self-experimentation occurred in the first half of the 20th century. Eight deaths were recorded. A number of the investigators enjoyed successful careers, including the receipt of Nobel Prizes. Although self-experimentation by physicians and other biological scientists appears to be in decline, the courage of those involved and the benefits to society cannot be denied.

  15. Introduction of Nuclear Instrumentations and Radiation Measurements in Experimental Fast Reactor 「JOYO」

    OpenAIRE

    大戸 敏弘; 鈴木 惣十

    1992-01-01

    This report introduces the nuclear instrumentation system and major R&D (research and development) activities using radiation measurement techniques in Experimental Fast Reactor "JOYO". In the introduction of the nuclear instrumentation system, following items are described; (1)system function (2)roles as a reactor plant equipment (3)specifications and charactelistics of neutron detectors, (4)construction and layout of the system. For reactor dosimetry at various irradiation tests and surveil...

  16. Radiative corrections for the direct detection of neutralino dark matter and its relic density

    Energy Technology Data Exchange (ETDEWEB)

    Steppeler, Patrick Norbert

    2016-07-01

    entering the Boltzmann equation in many scenarios of the MSSM. The Boltzmann equation allows to determine the neutralino relic density, i.e. to predict their present abundance. This prediction can be checked experimentally and is thus of great phenomenological relevance. Measurements of the temperature fluctuations of the cosmic microwave background permit to determine the relic density precisely. Comparing the theoretical prediction with the experimental finding allows to exclude large fractions of the MSSM parameter space. In order to maximally benefit from the experimental precision, it is necessary to minimise theoretical uncertainties and to include the aforementioned radiative corrections. The radiative corrections to the elastic neutralino-nucleon scattering and the corresponding relic density have been implemented into the numerical package Dark matter at next-to-leading order. With the help of this program, we perform a phenomenological investigation and analyse the impact of the radiative corrections. It turns out that the neutralino relic density depends not on a single but a multitude of gaugino (co)annihilation processes in parallel quite often. The calculated radiative corrections lead to a relative shift of the relic density of up to 10%, which is significantly larger than the experimental uncertainty (±2% at the 1σ confidence level) and demonstrates that these corrections should be included when identifying the cosmologically preferred region of the MSSM. Moreover, we investigate the relation between the relic density and the neutralino-nucleon cross sections. In the spin-independent case, the inclusion of radiative corrections leads to a relative shift roughly +14% in comparison to a tree-level calculation. This shift is comparable to typical recent nuclear uncertainties, which influence the prediction as well. The spin-dependent cross section is subject to even larger shifts and modified by up to -50% by radiative corrections.

  17. "Ant-egg" cataract revisited.

    Science.gov (United States)

    Clemmensen, Kåre; Enghild, Jan J; Ivarsen, Anders; Riise, Ruth; Vorum, Henrik; Heegaard, Steffen

    2017-01-01

    Hereditary congenital cataract varies immensely concerning location and form of the lens opacities. A specific and very rare phenotype is called "ant-egg" cataract first described in 1900. "Ant-eggs" have previously been examined using light microscopy, backscattered electron imaging and X-ray scans and electron microscopy. The purpose of this study was to further characterize "ant-egg" cataract using modern technology and display the history of the "ant-eggs" after cataract extraction. "Ant-eggs" were examined using Heidelberg SPECTRALIS Optical Coherence Tomography (OCT)(Heidelberg Engineering, Heidelberg, Germany). Ten "ant-eggs" were extracted; four of these as well as control tissue were analyzed by mass spectrometry (AB Sciex). Proteins were identified and their approximate abundances were determined. Immunohistochemical staining was carried out on the remaining "ant-eggs" for cytokeratin and S100. In anterior OCT-images, the "ant-egg" structures are localized on the iris. Comparative pictures showed that they stayed in the same location for more than 45 years. Mass spectrometry of "ant-eggs" yielded a proteome of 56 different proteins. Eighteen of the 56 "ant-egg" proteins (32 %) were neither present in our controls nor in a known fetal lens proteome. Among these were cytokeratin and Matrix-Gla protein. Immunohistochemical reactions were positive for cytokeratin and S100. This study demonstrates the previously unknown protein composition of the "ant-egg" structures in "ant-egg" cataract. Eighteen of these proteins are not natively found in the human lens. Moreover, "ant-eggs" do not vary over time, after cataract extraction, regarding size and location.

  18. [Experimental study on preclinical quality control, urgent poison and irritation of Dendrobium aurantiacum eye drops, a class I new drug against diabetic cataract].

    Science.gov (United States)

    Yi, Yan-Qun; Yang, Qiao-Hong; Su, Jun-Fang; Chen, Jian; Qi, Hui; Chen, Dan; Wei, Xiao-Yong

    2013-04-01

    To establish a quality control method of Dendrobium aurantiacum eye drops, in order to evaluate acute toxicity, irritation and irritability and lay a foundation for its development and utilization in the future. The content of gigantol and SA in D. aurantiacum eye drops were determined by high-performance liquid chromatography (HPLC). The linear ranges of gigantol and SA were 0.040 8-1.530 0 g x L(-1) (r = 0.999 9) and 0.100 8-0.504 0 g x L(-1) (r = 0.999 9), with the average recoveries being 100.8%, 99.84%, and RSD being 1.4%, 1.8% (n = 9) respectively. The sample solution was stable at room temperature within 72 h. The acute toxicity test showed no toxic reaction of D. aurantiacum eye drops in mice. The irritating test for single-dose and multiple-dose administrations of D. aurantiacum eye drops and physiological saline in rabbit eyes and skin, as well as the allergic test in guinea pigs showed no eye irritation and skin irritation and irritability. These findings indicated that D. aurantiacum eye drops are safe and stable, with a good druggability.

  19. The Palaeoclimate and Terrestrial Exoplanet Radiative Transfer Model Intercomparison Project (PALAEOTRIP: experimental design and protocols

    Directory of Open Access Journals (Sweden)

    C. Goldblatt

    2017-11-01

    Full Text Available Accurate radiative transfer calculation is fundamental to all climate modelling. For deep palaeoclimate, and increasingly terrestrial exoplanet climate science, this brings both the joy and the challenge of exotic atmospheric compositions. The challenge here is that most standard radiation codes for climate modelling have been developed for modern atmospheric conditions and may perform poorly away from these. The palaeoclimate or exoclimate modeller must either rely on these or use bespoke radiation codes, and in both cases rely on either blind faith or ad hoc testing of the code. In this paper, we describe the protocols for the Palaeoclimate and Terrestrial Exoplanet Radiative Transfer Model Intercomparison Project (PALAEOTRIP to systematically address this. This will compare as many radiation codes used for palaeoclimate or exoplanets as possible, with the aim of identifying the ranges of far-from-modern atmospheric compositions in which the codes perform well. This paper describes the experimental protocol and invites community participation in the project through 2017–2018.

  20. Results of cataract surgery in elderly people from Jatibonico municipality.

    Directory of Open Access Journals (Sweden)

    Arelys Caraballo Díaz

    2012-03-01

    Full Text Available A cataract is considered a disease of great magnitude and importance due to the decrease of visual acuity it causes and because it is widespread in the world. A descriptive study was conducted in order to describe the results of cataract surgery by extracting the extracapsular lens and placing an intraocular lens in elderly people operated on at the "Camilo Cienfuegos" General Hospital in the province of Sancti Spiritus, belonging to Jatibonico municipality in the period from January 3 to December 31, 2008. The population consisted of all cataract surgery patients aged 60 and over. 187 patients. The following variables were used: sex, age, eye diseases associated complications and visual results after placing an intraocular lens. Age between 60 and 69 years (78%, and female sex (29% were predominant. Posterior capsule rupture (34% and its opacity (34% were the main intraoperative and postoperative complications. Despite complications, there was an improvement of visual acuity evident after the completion of surgery.

  1. A sudden total loss of vision after routine cataract surgery.

    Science.gov (United States)

    Lartey, S; Armah, P; Ampong, A

    2013-06-01

    We share our experience of a 50-year-old controlled hypertensive woman who had routine cataract surgery in her left eye. She was given retrobulbar Xylocaine with adrenalin and postoperative gentamycin. She subsequently became blind in the operated eye after developing macular infarction by the first day post operative and optic atrophy by 2 months postoperative. This could have been caused by vascular occlusion in an already compromised artherosclerosed vessels. It could also have been due to gentamyin toxicity. Gentamycin injection given subconjunctivally is known to rarely result in severe retinal toxicity. This case illustrates that even though cataract surgery is considerd a simple routine procedure, and is performed in high volumes, it is not without its blinding complications. We recommend that the use of adrenaline in xylocaine should be used with caution in hypertensive patients and also the routine use of subconjunctival gentamycin injection after cataract surgery should be reviewed and other modes of endophthalmitis prophylaxis be considered.

  2. The challenges in improving outcome of cataract surgery in low and middle income countries

    Directory of Open Access Journals (Sweden)

    Robert Lindfield

    2012-01-01

    Full Text Available Cataract is the leading cause of blindness globally and surgery is the only known measure to deal with it effectively. Providing high quality cataract surgical services is critical if patients with cataract are to have their sight restored. A key focus of surgery is the outcome of the procedure. In cataract surgery this is measured predominantly, using visual acuity. Population- and hospital-based studies have revealed that the visual outcome of cataract surgery in many low and middle income settings is frequently sub-optimal, often failing to reach the recommended standards set by the World Health Organization (WHO. Another way of measuring outcome of cataract surgery is to ask patients for their views on whether surgery has changed the functioning of their eyes and their quality of life. There are different tools available to capture patient views and now, these patient-reported outcomes are becoming more widely used. This paper discusses the visual outcome of cataract surgery and frames the outcome of surgery within the context of the surgical service, suggesting that the process and outcome of care cannot be separated. It also discusses the components of patient-reported outcome tools and describes some available tools in more detail. Finally, it describes a hierarchy of challenges that need to be addressed before a high quality cataract surgical service can be achieved.

  3. Selenium concentrations in serum, lens and aqueous humour of patients with senile cataract.

    Science.gov (United States)

    Karaküçük, S; Ertugrul Mirza, G; Faruk Ekinciler, O; Saraymen, R; Karaküçük, I; Ustdal, M

    1995-08-01

    Selenium (Sc) is a trace element which incorporates into the selenoenzyme glutathion peroxidase. Cataractogenesis may be caused either by the excess or deficiency of this trace element. More recently, its potential of becoming a possible environmental pollutant has been emphasized. In an attempt to reveal the relationship of this element with cataractogenesis, we detected its level in 48 serum, 36 lens and 9 aqueous humour samples of 48 patients with senile cataract, comparing the results with appropriate controls. Selenium levels (mean +/- SD) of cataractous patients were found to be 0.28 +/- 0.04 microgram/ml (CI: 0.27 to 0.29 microgram/ml) in sera (controls: 0.32 +/- 0.04 microgram/ml; CI: 0.30 to 0.34 microgram/ml, p cataract and 0.28 +/- 0.02 microgram/ml (CI: 0.27 to 0.30 microgram/ml) in the cortical cataract. Lens Se levels, on the other hand, were detected as 5.91 +/- 3.56 microgram/g dry weight (CI:4.49 to 7.33 microgram/g dry weight) in the nuclear cataract and 4.47 +/- 1.40 microgram/g dry weight (CI: 3.68 to 5.26 microgram/g dry weight) in the cortical cataract. It is anticipated that decreased Se in aqueous humour and sera of patients with senile cataract may reflect defective antioxidative defense systems which may lead to the formation of cataract.

  4. The challenges in improving outcome of cataract surgery in low and middle income countries

    Science.gov (United States)

    Lindfield, Robert; Vishwanath, Kalluru; Ngounou, Faustin; Khanna, Rohit C

    2012-01-01

    Cataract is the leading cause of blindness globally and surgery is the only known measure to deal with it effectively. Providing high quality cataract surgical services is critical if patients with cataract are to have their sight restored. A key focus of surgery is the outcome of the procedure. In cataract surgery this is measured predominantly, using visual acuity. Population- and hospital-based studies have revealed that the visual outcome of cataract surgery in many low and middle income settings is frequently sub-optimal, often failing to reach the recommended standards set by the World Health Organization (WHO). Another way of measuring outcome of cataract surgery is to ask patients for their views on whether surgery has changed the functioning of their eyes and their quality of life. There are different tools available to capture patient views and now, these patient-reported outcomes are becoming more widely used. This paper discusses the visual outcome of cataract surgery and frames the outcome of surgery within the context of the surgical service, suggesting that the process and outcome of care cannot be separated. It also discusses the components of patient-reported outcome tools and describes some available tools in more detail. Finally, it describes a hierarchy of challenges that need to be addressed before a high quality cataract surgical service can be achieved. PMID:22944761

  5. Photostability of Isovaline and its Precursor 5-Ethyl-5-methylhydantoin Exposed to Simulated Space Radiations

    Directory of Open Access Journals (Sweden)

    Takeo Kaneko

    2012-01-01

    Full Text Available Aqueous solutions of isovaline and its precursor molecule, 5-ethyl-5-methylhydantoin, were irradiated with ultraviolet and γ-ray photons, to evaluate their structural stability against space radiation. The degree of photolysis was measured and irradiation products were identified using chiral, reversed-phase and ion-exchange high-performance liquid chromatography. The experimental results show that the degree of photolysis of 5-ethyl-5-methylhydantoin is more significant than that of isovaline under ultraviolet light irradiation, while the results under γ-ray irradiation are the opposite. As the products of isovaline photolysis, aspartic acid, serine, glutamic acid and alanine were dominantly detected.

  6. Impact of cataract surgery in reducing visual impairment: a review.

    Science.gov (United States)

    Khandekar, Rajiv; Sudhan, Anand; Jain, B K; Deshpande, Madan; Dole, Kuldeep; Shah, Mahul; Shah, Shreya

    2015-01-01

    The aim was to assess the impact of cataract surgeries in reducing visual disabilities and factors influencing it at three institutes of India. A retrospective chart review was performed in 2013. Data of 4 years were collected on gender, age, residence, presenting a vision in each eye, eye that underwent surgery, type of surgery and the amount the patient paid out of pocket for surgery. Visual impairment was categorized as; absolute blindness (no perception of light); blind (visual impairment (SVI) (visual impairment (6/18-6/60) and; normal vision (≥6/12). Statistically analysis was performed to evaluate the association between visual disabilities and demographics or other possible barriers. The trend of visual impairment over time was also evaluated. We compared the data of 2011 to data available about cataract cases from institutions between 2002 and 2009. There were 108,238 cataract cases (50.6% were female) that underwent cataract surgery at the three institutions. In 2011, 71,615 (66.2%) cases underwent surgery. There were 45,336 (41.9%) with presenting vision visual disability. The goal of improving vision related quality of life for cataract patients during the early stages of visual impairment that is common in industrialized countries seems to be non-attainable in the rural India.

  7. Radiations from GSM Base Stations and its Biological Effects

    African Journals Online (AJOL)

    Michael Horsfall

    electromagnetic exposure in the microwave range and radiofrequency (RF) radiation on exposed organisms and humans (Markov and Kostarakis,. 2007). While several studies have indicated that exposure of biological systems to low level RF radiation caused adverse biological effects, other studies have indicated that at ...

  8. Estimation of global solar radiation using solar PV and its ...

    African Journals Online (AJOL)

    Solar energy is the prime energy source of hydrologic parameter such as evapotranspiration and aerodynamic parameter like wind. Knowledge of daily global solar radiation is important to estimate all solar energy related parameters. In this study, mean daily global solar radiation at Haramaya University (HU) and Dire ...

  9. Computational Design of Epoxy/ Boron Carbide Nanocomposites for Radiation Shielding Applications

    Science.gov (United States)

    Bejagam, Karteek; Galehdari, Nasim; Espinosa, Ingrid; Deshmukh, Sanket A.; Kelkar, Ajit D.

    An individual working in industries that include nuclear power plants, healthcare industry, and aerospace are knowingly or unknowingly exposed to radiations of different energies. Exposure to high-energy radiations such as α/ β particle emissions or gamma ray electromagnetic radiations enhances the health risks that can lead to carcinogenesis, cardiac problems, cataracts, and other acute radiation syndromes. The best possible solution to protect one from the exposure to radiations is shielding. In the present study, we have developed a new algorithm to generate a range of different structures of Diglycidyl Ether of Bisphenol F (EPON 862) and curing agent Diethylene Toluene Diamine (DETDA) resins with varying degrees of crosslinking. 3, 5, and 10 weight percent boron carbide was employed as filling materials to study its influence on the thermal and mechanical properties of composite. We further conduct the reactive molecular dynamics (RMD) simulations to investigate the effect of radiation exposure on the structural, physical, and mechanical properties of these Epoxy/Boron Carbide nanocomposites. Where possible the simulation results were compared with the experimental data.

  10. Review Recent progress in identification and characterization of loci associated with sex-linked congenital cataract.

    Science.gov (United States)

    Zhang, D D; Du, J Z; Topolewski, J; Wang, X M

    2016-07-29

    Congenital cataract is a common cause of blindness in children; however, its pathogenesis remains unclear. Genetic factors have been shown to play an important role in the pathogenesis of congenital cataract. The current genetic models of congenital cataract include autosomal dominant, autosomal recessive, and sex-linked inheritance. Sex-linked congenital cataract could be inherited through the X or Y chromosome. Congenital cataract is a symptom associated with several X-linked disorders, including Nance-Horan syndrome, Lowe syndrome, Conradi-Hünermann-Happle syndrome, oculo-facio-cardio-dental syndrome, and Alport syndrome. On the other hand, the mechanism and characteristics of Y-linked congenital cataract remains to be identified. Despite its rarity, sex-linked congenital cataract has been known to seriously affect the quality of life of patients. In this review, we present our current understanding of the genes and loci associated with sex-linked congenital cataract. This could help identify novel approaches for the prevention, early diagnosis, and comprehensive disease treatment.

  11. Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

    Science.gov (United States)

    Widel, M

    2017-01-01

    For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

  12. Capsulotomy and hydroprocedures for nucleus prolapse in manual small incision cataract surgery

    Directory of Open Access Journals (Sweden)

    Venkatesh Rengaraj

    2009-01-01

    Full Text Available Manual small incision cataract surgery (MSICS involves the manual removal of nucleus through a scleral tunnel. To achieve 100% success every time, one has to do a good capsulotomy and should master the technique to prolapse the nucleus into anterior chamber. During conversion from extracapsular cataract surgery to MSICS, one can perform a can-opener capsulotomy and prolapse the nucleus. However, it is safer and better to perform a capsulorrhexis and hydroprolapse the nucleus, as it makes the rest of the steps of MSICS comfortable. Use of trypan blue in white and brown cataracts makes the capsulorrhexis and prolapse simple and safe. Extra caution should be taken in cases with hypermature cataracts with weak zonules and subluxated cataracts.

  13. Simulation-based certification for cataract surgery

    DEFF Research Database (Denmark)

    Thomsen, Ann Sofia Skou; Kiilgaard, Jens Folke; Kjaerbo, Hadi

    2015-01-01

    PURPOSE: To evaluate the EyeSi(™) simulator in regard to assessing competence in cataract surgery. The primary objective was to explore all simulator metrics to establish a proficiency-based test with solid evidence. The secondary objective was to evaluate whether the skill assessment was specific...... to cataract surgery. METHODS: We included 26 ophthalmic trainees (no cataract surgery experience), 11 experienced cataract surgeons (>4000 cataract procedures) and five vitreoretinal surgeons. All subjects completed 13 different modules twice. Simulator metrics were used for the assessments. RESULTS: Total...... than the experienced cataract surgeons (p = 0.32). CONCLUSION: We have established a performance test, consisting of seven modules on the EyeSi(™) simulator, which possess evidence of validity. The test is a useful and reliable tool for assessment of both cataract surgical and general microsurgical...

  14. Factors associated with strabismus after cataract extraction and primary intraocular lens implantation in congenital cataracts

    Directory of Open Access Journals (Sweden)

    Soo Jung Lee

    2014-06-01

    Full Text Available AIM: To evaluate factors associated with the development of strabismus after cataract extraction and primary intraocular lens implantation.METHODS: The medical records of 122 patients, aged 1.5mo to 9y, who had undergone cataract extraction with primary intraocular lens implantation between January 1993 and August 2011 were reviewed. Fourteen patients (17 eyes with strabismus before cataract surgery were excluded. Patients were divided into those with congenital bilateral cataracts (64 patients, 128 eyes and those with unilateral cataracts (44 patients, 44 eyes. The associations between the development of strabismus and age at cataract surgery, pre- and post-cataract extraction corrected distance visual acuity (CDVA, interocular CDVA difference, nystagmus, surgical method, and secondary cataract were evaluated.RESULTS: Factors significantly associated with the development of strabismus included age at cataract surgery (≤1y, preoperative mean CDVA ≤20/100, presence of nystagmus in the bilateral cataract group and postoperative interocular CDVA difference >20/70 in the unilateral group. Postoperative CDVA ≤20/100 and preservation of posterior capsule, and presence of secondary cataract were significant factors in both groups.CONCLUSION: Children with congenital cataracts should be monitored carefully after cataract surgery for the development of strabismus, especially when they underwent surgery at age ≤1y, and they have nystagmus, large postoperative interocular CDVA difference, poor preoperative and postoperative CDVA, preservation of the posterior capsule, or secondary cataract.

  15. Evaluation of povidone-iodine applications in cataract surgery

    Directory of Open Access Journals (Sweden)

    Xi Zhang

    2013-09-01

    Full Text Available As a routine measure to prevent intraocular inflammation, rinsing conjunctival sac with povidone-iodine(PVP-Ihas been increasingly adopted in cataract surgery. It can effectively reduce the complications of cataract surgery, including endophthalmitis and corneal complications. However, PVP-I itself has certain side effects. Therefore, to achieve the best bactericidal effect and to avoid eye injury, it is necessary to find out the optimal treatment duration and concentration. This article offers a review on the latest researches worldwide in this field.

  16. Experimental investigation of the radiation shielding efficiency of a MCP detector in the radiation environment near Jupiter's moon Europa

    Science.gov (United States)

    Tulej, M.; Meyer, S.; Lüthi, M.; Lasi, D.; Galli, A.; Piazza, D.; Desorgher, L.; Reggiani, D.; Hajdas, W.; Karlsson, S.; Kalla, L.; Wurz, P.

    2016-09-01

    detector compares to the MCP rate of the incident electron beam. We define key performance parameters for the shielding and show direction of its improvements by introducing additional layer of material to attenuate γ-rays and reduce the MCP sensitivity to the penetrating radiation. The experiments also verify the predictions by modelling tools used currently for optimisation of shielding against high-energy particles.

  17. Hereditary radiation effects in offspring of the second and third generations after irradiation of both grandparents. Experimental studies and Hereditary radiation effects in offspring of the first generation after irradiation of one and both parents. Experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Nefyodova, I.; Nefyodov, I [Medical Radiological Research Centre RAMS, Obninsk (Russian Federation)

    2000-05-01

    The parent study has investigated hereditary radiation effects in progeny of the second and third generations of Wistar rats after irradiation of both grandparents with doses of 2-4 Gy. Attention was focused on the relationship between stages of gametogenesis in grandparents at the moment of radiation exposure and death of progeny in embryogenesis and early postnatal ontogenesis. Totals of 4207 mature males and females Wistar rats, 13539 offspring of the second generation (F2) and 746 offspring of the third generation (F3) were the subjects of investigation. Male and female rat grandparents (P) of 220-250 g were exposed to an external single irradiation by gamma rays to doses of 2,3 and 4 Gy at a dose rate of 0.003 Gy.s{sup -1} ({sup 60}Co source). The animals were mated at different times after irradiation so that different stages in gametogenesis were studied. When F1 sexual maturity was achieved, F1 males of each experimental group were mated with intact females to produce F2 descendants from the father's line and conversely F1 females use mated with intact males to produce F2 descendants from the mother's line. Embryogenesis F2 was studied after euthanasia of some females by ether on the 20th day of pregnancy. The fetuses were scored for size and mass, pathology of viscera and skeleton and the total, pre- and postimplantation death of embryos was calculated. In addition development of young rats was observed for 30 days after the birth. The numbers surviving on the 1st and 30th days after the birth were calculated, giving the death rate for this period of time. It was stated: for F2; radiation effects depend upon a dose stage of gametogenesis of both P at the time of radiation exposure; F2 death in embryogenesis occurred only after irradiation of P with a dose of 4 Gy; ossification disorder of the skeleton in F2 embryogenesis was found in all experimental groups; high F2 death is observed after birth which depends much more on the stage of

  18. Pediatric cataract surgery in Madagascar

    African Journals Online (AJOL)

    2013-03-28

    Mar 28, 2013 ... their encounters with the eye care facility, only 3 (3.5%) were provided with glasses. At last documented follow-up, 2.7% of the children had 6/18 vision or better. Conclusions: In Madagascar, presentation for congenital and developmental cataract is very late, visual outcome poor and follow-up inadequate.

  19. The Pediatric Cataract Register (PECARE)

    DEFF Research Database (Denmark)

    Haargaard, Birgitte; Nyström, Alf; Rosensvärd, Annika

    2015-01-01

    examination with a pencil light at age 5 weeks, whereas newborn red reflex examination using a handheld ophthalmoscope is routine protocol in Swedish maternity wards. Data regarding age of referral were derived from the Pediatric Cataract Register (PECARE). All children operated on before 1 year of age...

  20. Driving When You Have Cataracts

    Science.gov (United States)

    ... to plan car trips to avoid times when vision may be most affected; for example, driving west at dusk into a setting sun or ... lens will likely be replaced with a clear, artificial lens. With a new, clear lens, you will most likely be able to keep driving safely for many years to come. Cataract surgery ...

  1. Conference on Radiation and its Effects on Components and Systems

    CERN Document Server

    2017-01-01

    The aim of RADECS conferences is to provide an annual European forum for the presentation and discussion of the latest advances in the field of radiation effects on electronic and photonic materials, devices, circuits, sensors, and systems. The scope of the conference encompasses technological processes and design techniques for producing radiation tolerant systems for space, aeronautical or terrestrial applications, as well as relevant methodologies for their characterization and qualification. The conference features a technical program, an Industrial Exhibit, and one day tutorial or ‘short course’ on radiation effects. The technical program includes oral and poster sessions and round tables.

  2. Experimental determination of monoethanolamine protonation constant and its temperature dependency

    Directory of Open Access Journals (Sweden)

    Ma’mun Sholeh

    2017-01-01

    Full Text Available Carbon dioxide as one of the major contributors to the global warming problem is produced in large quantities by many important industries and its emission seems to rise from year to year. Aminebased absorption is one of the methods to capture CO2 from its sources. As a reactive system, mass transfer and chemical reaction take place simultaneously. In a vapor-liquid equilibrium model for the CO2-amine-water system, some parameters such as mass transfer coefficients and chemical equilibrium constants need to be known. However, some parameters could be determined experimentally and the rests could be regressed from the model. The protonation constant (pKa, as one of the model parameters, could then be measured experimentally. The purpose of this study is to measure the pKa of monoethanolamine (MEA at a range of temperatures from 303 to 330K by a potentiometric titration method. The experimental data obtained were in a good agreement with the literature data. The pKa data from this work together with those from the literature were then correlated in an empirical correlation to be used for future research.

  3. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Nestor Fonseca [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

    2011-01-15

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure. (author)

  4. Experimental study of hydronic panels system and its environment

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca Diaz, Nestor, E-mail: nestorfonseca5@hotmail.co [University of Liege Belgium, Thermodynamics Laboratory, Campus du Sart Tilman, Bat: B49 - P33, B-4000 Liege (Belgium); Universidad Tecnologica de Pereira, Facultad de Ingenieria Mecanica (Colombia)

    2011-01-15

    An experimental analysis of hydronic cooling or heating ceiling panels coupled to the building is present in this investigation as a part of the commissioning study of this system. Two test chambers are adapted in a way to reproduce the interaction of the system to the building (windows, internal thermal loads distribution, building structure and ventilation). A series of experimental tests were performed in which the main objective is to observe the influence of parameters such as the water mass flow rate, supply water temperature, thermal load distribution, window and ventilation system effects on the hydronic ceiling capacity and comfort conditions. Test results show that the influence of asymmetric surfaces temperatures inside the room, especially the window effect is not negligible. Then, it is clear that the cooling hydronic ceiling must be evaluated coupled to the building systems and structure.

  5. Vitrectorhexis versus forceps posterior capsulorhexis in pediatric cataract surgery

    Directory of Open Access Journals (Sweden)

    Lav Kochgaway

    2013-01-01

    Full Text Available This study was done to compare the results of posterior continuous curvilinear capsulorhexis created using forceps with those created using vitrector in eyes suffering from congenital cataract. Vitrectorhexis term was first used by Wilson et al in 1999. [1] Fifty eyes with congenital and developmental cataract were included in this study. The posterior capsulorhexis was created using utrata forceps in 17 eyes or through a vitrector in 33 eyes. Forceps capsulorhexis was performed before IOL implantation, while vitrectorhexis was performed after IOL implantation in the bag. The results of both the surgery were compared using the following criteria: incidence of extension of rhexis, ability to achieve posterior rhexis of appropriate size, ability to implant the IOL in the bag, the surgical time, and learning curve. Vitrectorhexis after IOL implantation was an easy to learn alternative to manual posterior continuous curvilinear capsulorhexis in pediatric cataract surgery. It was more predictable and reproducible, with a short learning curve and lesser surgical time.

  6. Research progress of surgery for age-related macular degeneration with cataract

    Directory of Open Access Journals (Sweden)

    Xiao-Liang Zheng

    2017-09-01

    Full Text Available Age-related macular degeneration(AMDand cataract are the most common causes of low vision worldwide. Nowadays, there is still a controversy about whether cataract surgery should be taken in patients combined with AMD and when should the surgery be taken. The aim of this review is to assess the influence of cataract surgery on the occurrence and development of AMD, to analyze the risk factors, to explore the occasion of cataract surgery in patients with AMD, and joint with anti-vascular endothelial growth factor(VEGFtreatment, also including the development and application of intraocular lens. It helps to avoid and postpone the development and progression of macular degeneration after cataract surgery and get good visual outcome.

  7. Effect of Kohl-Chikni Dawa – a compound ophthalmic formulation of Unani medicine on naphthalene-induced cataracts in rats

    Directory of Open Access Journals (Sweden)

    Zaidi Zehra

    2002-12-01

    Full Text Available Abstract Background Cataracts are the leading cause of blindness worldwide, accounting for 13-27% of cases. Kohl-Chikni Dawa (KCD is reputed for its beneficial effects in the treatment of premature cataracts. However, its efficacy is yet to be tested. To investigate the rationality of the therapeutic use of Kohl-Chikni Dawa (KCD in Unani medicine. Methods The effect of Kohl-Chikni Dawa eye drops on naphthalene-induced cataracts in rats was investigated by slit-lamp biomicroscopic analysis. The normal group of experimental animals was administered with mineral oil (orally, while other groups were given naphthalene (orally along with local application of KCD eye drops (once and twice daily, placebo and distilled water (twice daily. Initial morphological changes of the lenses were observed twice a week for two weeks, and thereafter once a week for four weeks. Results Local application of KCD (twice daily caused significant reduction in the lens opacification after 2 to 4 weeks of naphthalene administration. Conclusion KCD eye drops may have the potential to delay progression of naphthalene-induced cataracts in rats.

  8. Solar radiation and its penetration in a tropical estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.; Bhattathiri, P.M.A.; Abidi, S.A.H.

    The Cochin Backwater which is an estuarine area on the west coast of India receives maximum solar radiation from December to March and minimum from June to September. During the monsoon months the estuary becomes highly turbid as a result...

  9. Radiation protection design of the APPA experimental hall at the FAIR facility; Strahlenschutzplanung fuer die APPA-Experimentierhalle bei FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Kissel, R.; Braeuning-Demian, A.; Conrad, I.; Evdokimov, A.; Lang, R.; Radon, T.; Zieser, B. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Belousov, A. [NASA, Pasadena, CA (United States). Jet Propulsion Lab.; Fehrenbacher, G. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); FAIR - Facility for Antiproton and Ion Research in Europe GmbH, Darmstadt (Germany)

    2016-07-01

    The APPA-research program (Atomic, Plasma Physics and Applications) comprises experiments for fundamental research in atomic and plasma physics, biophysics and materials research. A dedicated building for the experimental areas including a technical supply annex is planned. In the hall are located four different experimental setups for the four APPA collaborations. Two beamlines for protons and heavy ions, both from the SIS18 and SIS100 synchrotrons are designed. The demands for beam energies, intensities and time structure differ significantly among the experiments. Consequently, different types of beams will be used, for example uranium beams with energies of 2 GeV/nucleon and an intensity of 3 x 10{sup 11} ions/pulse (pulse length of the order of hundred nanoseconds, repetition period 180 seconds). Another experiment requires a proton beam with energies of around 10 GeV and a primary intensity of 5 x 10{sup 10} protons/second. The highest interaction rate is expected by the plasma physics experiments with about 50 % of the primary intensity. The remaining beam will be stopped in a so called beam dump producing further radiation, especially neutron radiation which must be shielded. For the design of the shielding it is necessary to know the spatial distribution of the dose rate for uranium beams and for proton beams with different energies and intensities in the experimental hall. The aim for the shielding layout is to achieve a dose rate below 0,5 μSv/hour at the premises.

  10. Experimental Demonstration of a Synthetic Lorentz Force by Using Radiation Pressure.

    Science.gov (United States)

    Šantić, N; Dubček, T; Aumiler, D; Buljan, H; Ban, T

    2015-09-02

    Synthetic magnetism in cold atomic gases opened the doors to many exciting novel physical systems and phenomena. Ubiquitous are the methods used for the creation of synthetic magnetic fields. They include rapidly rotating Bose-Einstein condensates employing the analogy between the Coriolis and the Lorentz force, and laser-atom interactions employing the analogy between the Berry phase and the Aharonov-Bohm phase. Interestingly, radiation pressure - being one of the most common forces induced by light - has not yet been used for synthetic magnetism. We experimentally demonstrate a synthetic Lorentz force, based on the radiation pressure and the Doppler effect, by observing the centre-of-mass motion of a cold atomic cloud. The force is perpendicular to the velocity of the cold atomic cloud, and zero for the cloud at rest. Our novel concept is straightforward to implement in a large volume, for a broad range of velocities, and can be extended to different geometries.

  11. Traumatic cataract in patient with anterior megalophthalmos: Case report.

    Science.gov (United States)

    Chlasta-Twardzik, Edyta; Nowińska, Anna; Wąs, Paweł; Jakubowska, Agnieszka; Wylęgała, Edward

    2017-07-01

    Megalophthalmos anterior is a rare, bilateral, nonprogressive, hereditary, congenital disorder, characterized by the enlargement of all anterior segment structures of the eye, with megalocornea, iris atrophy, and zonular abnormalities commonly found. Usually almost asymptomatic in young patients, with most complaints concerning blurred vision due to the common corneal astigmatism, it might in time lead to several complications including premature cataract formation and pigmentary glaucoma. This review presents the case of a 47-year old patient referred to our clinic for traumatic cataract surgery, with striking bilateral megalocornea, somehow overlooked during previous ophthalmic examinations in his local outpatient clinic. We noticed markedly enlarged corneas and deepened anterior chambers of his both eyes, accompanied by intumescent, white cataract of the right eye, and incipient cortical cataract of the left eye. Best corrected visual acuity (BCVA) was counting fingers in the right eye and 20/25 in the left eye. Additional examination revealed multiple abnormalities of the anterior segment, leading to the diagnosis of anterior megalophthalmos. It is astounding the patient remained undiagnosed during previous examinations, with his megalocornea and remarkably deep anterior chamber so apparent. We performed standard phacoemulsification procedure, with 3 piece posterior chamber intraocular lens (PCIOL) implantation into the lens capsule. The surgery was uneventful, with postoperative BCVA of 20/20 in the right eye, and no dislocation of the lens in 9-month observation period. Complicated cataract in patients with anterior megalophthalmos can be successfully treated with standard phacoemulsification procedure followed by the bag PCIOL implantation.Care needs to be taken during cataract surgery in these patients, as zonular abnormalities and lens enlargement are common, resulting in increased rate of intra- and postoperative complications. As patients with anterior

  12. Natural therapies for ocular disorders, part two: cataracts and glaucoma.

    Science.gov (United States)

    Head, K A

    2001-04-01

    Pathophysiological mechanisms of cataract formation include deficient glutathione levels contributing to a faulty antioxidant defense system within the lens of the eye. Nutrients to increase glutathione levels and activity include lipoic acid, vitamins E and C, and selenium. Cataract patients also tend to be deficient in vitamin A and the carotenes, lutein and zeaxanthin. The B vitamin riboflavin appears to play an essential role as a precursor to flavin adenine dinucleotide (FAD), a co-factor for glutathione reductase activity. Other nutrients and botanicals, which may benefit cataract patients or help prevent cataracts, include pantethine, folic acid, melatonin, and bilberry. Diabetic cataracts are caused by an elevation of polyols within the lens of the eye catalyzed by the enzyme aldose reductase. Flavonoids, particularly quercetin and its derivatives, are potent inhibitors of aldose reductase. Glaucoma is characterized by increased intraocular pressure (IOP) in some but not all cases. Some patients with glaucoma have normal IOP but poor circulation, resulting in damage to the optic nerve. Faulty glycosaminoglycan (GAG) synthesis or breakdown in the trabecular meshwork associated with aqueous outflow has also been implicated. Similar to patients with cataracts, those with glaucoma typically have compromised antioxidant defense systems as well. Nutrients that can impact GAGs such as vitamin C and glucosamine sulfate may hold promise for glaucoma treatment. Vitamin C in high doses has been found to lower IOP via its osmotic effect. Other nutrients holding some potential benefit for glaucoma include lipoic acid, vitamin B12, magnesium, and melatonin. Botanicals may offer some therapeutic potential. Ginkgo biloba increases circulation to the optic nerve; forskolin (an extract from Coleus forskohlii) has been used successfully as a topical agent to lower IOP; and intramuscular injections of Salvia miltiorrhiza have shown benefit in improving visual acuity and

  13. Prevention of cataract in diabetic mice by topical pyruvate

    Directory of Open Access Journals (Sweden)

    Hegde KR

    2011-08-01

    Full Text Available KR Hegde1,3, S Kovtun1, SD Varma1,21Ophthalmology and Visual Sciences, 2Biochemistry and Molecular Biology, University of Maryland School of Medicine, 3Coppin State University, Department of Natural Sciences, Baltimore, MD, USABackground: It has been previously reported that oral administration of sodium pyruvate inhibits oxidative stress and cataract formation in diabetic animals. With a view to exploring the clinical usefulness of these findings, this study examined its preventive effect when administered topically as an eye drop.Methods: Diabetes was induced by intraperitoneal injections of streptozotocin. At the onset of diabetes, an eye drop preparation containing 2.5% sodium pyruvate was administered six times a day at 90-minute intervals. Treatment was continued for 6 weeks. Cataract formation was monitored ophthalmoscopically after mydriasis with 1% tropicamide eye drops. Subsequently, the treated and untreated diabetic animals and the age-matched normal controls were euthanized, their eyes enucleated, and the lenses isolated for biochemical assessment of protein glycation and glutathione levels.Results: Treatment with pyruvate eye drops was found to be significantly effective in inhibiting protein glycation. Glutathione levels were also better maintained. In addition, ophthalmoscopic examination revealed that the incidence of cataract in the pyruvate-treated group was only 12% as compared with the untreated diabetics in whom the incidence was 73%. Cataracts at this stage were largely equatorial.Conclusion: The results demonstrate that topical application of pyruvate can potentially be useful in attenuating or preventing cataract formation induced by diabetes and other conditions of oxidative stress.Keywords: pyruvate eye drops, diabetic cataract, protein glycation, oxidative stress

  14. Cataract surgery and methods of wound closure: a review

    Directory of Open Access Journals (Sweden)

    Matossian C

    2015-05-01

    Full Text Available Cynthia Matossian,1 Sarah Makari,2 Richard Potvin2 1Matossian Eye Associates, Pennington, NJ, 2Science in Vision, Akron, NY, USA Abstract: Clear corneal incisions are routinely used in cataract surgery, but watertight wound closure may not always be achieved, which can increase the risk for anterior chamber fluid egress or ocular surface fluid ingress. A new US Food and Drug Administration-approved ocular sealant appears to have good efficacy in sealing clear corneal incisions; its use may be indicated when wound integrity is in question. Keywords: clear corneal incisions, wound closure, sealant, suture, stromal hydration, cataract surgery

  15. Cataract blindness and barriers to cataract surgical intervention in three rural communities of Oyo State, Nigeria.

    Science.gov (United States)

    Oluleye, T S

    2004-01-01

    The study was a community based field survey that used a rapid assessment method to determine the prevalence of cataract blindness in people aged 50 years and above in 3 rural communities. The purpose of the study was to determine the prevalence of cataract blindness and barriers to cataract surgical intervention in an area served by a health facility managed by a tertiary institution. Abedo, Akinyele and Ketepe Villages in Akinyele Local Government Area of Oyo State Nigeria were selected based on their nearness to the primary health care centre in Abedo. A total of 477 persons aged 50 years and above were seen being 73.3 percent of expected. Those with visual acuity of less than 3/60 in an eye and those with visual acuity of less than 3/60 in the better eye were examined in more details using a pen torch, an ophthalmoscope and tonometer to determine the cause of blindness. All persons who have had surgery were examined. The prevalence of blindness in persons aged 50 years and above was 1.47% and that of cataract blindness in the same age group in the villages was 0.84% constituting 57.14% of blindness. The main barriers to hospital presentation were cost of surgery (52.8%) and distance to hospital (33.8%). The constraints and limitations encountered during the study included rural-urban migration and population discrepancies between what obtained at the villages and those supplied by the Local Government Population Commission. It is hoped that this study will serve as a preliminary survey and a base line for further studies and the initiation of a blindness prevention programme in the area.

  16. Influence of ionizing radiation on the mechanical properties of BisGMA/TEGDMA based experimental resin

    Science.gov (United States)

    LMP, Campos; Boaro, LC; LKG, Santos; Parra, DF; Lugão, AB

    2015-10-01

    Dental restorative composites are activated by visible light and the polymerization process, known as direct technique, is initiated by absorbing light in a specific wavelength range (450-500 nm). However this technique presented some disadvantages. If light is not inserted correctly, layers uncured can cause countless damage to restoration, especially with regard to mechanical properties. A clinical alternative used to reduce the shortcomings of direct application is the use of composite resins for indirect application. These composites are adaptations of resins prepared for direct use, with differences mainly in the healing process. Besides the traditional photoactivation, indirect application composites may be submitted to particular curing conditions, such as a slow curing rate, heating, vacuum, and inert-gas pressure leading to an oxygen-free environment. However few studies have been conducted on the process of post-curing by ionizing radiation at low doses. On this sense the purpose of this study was to evaluate possible interactions of ionizing radiation in the post-curing process of the experimental composites based on BisGMA/TEGDMA filled with silica Aerosil OX-50 silanized. Characterization of the experimental composites was performed by thermogravimetry analysis, infrared spectroscopy, elastic modulus and flexural strength. Statistical analysis of results was calculated by one-way ANOVA/Tukey's test. Cross-linking of the polymeric matrix caused by ionizing radiation, influenced the thermal stability of irradiated specimens. FTIR analysis showed that the ionizing radiation induced a post-cure reaction in the specimens. The irradiation dose influenced directly the mechanical properties that showed a strong positive correlation between flexural strength and irradiation and between modulus strength and irradiation.

  17. Method for Determining Volumetric Efficiency and Its Experimental Validation

    Directory of Open Access Journals (Sweden)

    Ambrozik Andrzej

    2017-12-01

    Full Text Available Modern means of transport are basically powered by piston internal combustion engines. Increasingly rigorous demands are placed on IC engines in order to minimise the detrimental impact they have on the natural environment. That stimulates the development of research on piston internal combustion engines. The research involves experimental and theoretical investigations carried out using computer technologies. While being filled, the cylinder is considered to be an open thermodynamic system, in which non-stationary processes occur. To make calculations of thermodynamic parameters of the engine operating cycle, based on the comparison of cycles, it is necessary to know the mean constant value of cylinder pressure throughout this process. Because of the character of in-cylinder pressure pattern and difficulties in pressure experimental determination, in the present paper, a novel method for the determination of this quantity was presented. In the new approach, the iteration method was used. In the method developed for determining the volumetric efficiency, the following equations were employed: the law of conservation of the amount of substance, the first law of thermodynamics for open system, dependences for changes in the cylinder volume vs. the crankshaft rotation angle, and the state equation. The results of calculations performed with this method were validated by means of experimental investigations carried out for a selected engine at the engine test bench. A satisfactory congruence of computational and experimental results as regards determining the volumetric efficiency was obtained. The method for determining the volumetric efficiency presented in the paper can be used to investigate the processes taking place in the cylinder of an IC engine.

  18. [Cataract blindness in people 50 years old or older in a semirural area of northern Peru].

    Science.gov (United States)

    Pongo Aguila, Luis; Carrión, Rómulo; Luna, Winston; Silva, Juan Carlos; Limburg, Hans

    2005-01-01

    To determine the prevalence of blindness and of cataract blindness in persons 50 years of age or older in Piura and Tumbes, which are two departments in northern Peru, and to describe the coverage and quality of cataract surgery services in that area, and the barriers that prevent access to those services. Systematic sampling of persons 50 years old or older was done in Piura and Tumbes between August 2002 and March 2003, with 80 clusters of 60 people each being selected. Of the 4 800 persons chosen, 4,782 of them were examined, using a survey instrument that gathered general information on each person, the results of the visual acuity test and the lens examination, and information on cataract surgery or why that surgery had not been done. Visual acuity (VA) testing was done with a Snellen optotype with the letter "E," with sizes of 20/60 and 20/200 at distances of 6 m and 3 m, respectively, with the person using the visual correction (glasses) available. When the VA was less than 20/60 in one of the eyes, vision was tested with pinhole glasses. The prevalence of bilateral blindness (VA < 20/400) due to cataract, adjusted by age and sex, was 2.1% (95% confidence interval (CI): 1.7% to 2.6%). Among the 193 persons with bilateral blindness due to any cause, cataract was the cause in 104 of them (53.9%). The prevalence of blindness due to cataract or other causes increased with age and was higher in women than in men. Only 25% of the persons studied who needed cataract surgery had had that done. The prevalence of bilateral VA less than 20/200 due to unoperated cataract was 6.3% (95% CI: 5.3% to 7.3%); only 12% of the persons with that level of visual deficiency had had cataract surgery. The VA of 26% of the eyes operated on for cataract was lower than 20/200. The reasons given by persons who needed cataract surgery but who had not had it included not being able to pay for the operation (28%), lack of knowledge concerning cataracts (25%), fear of the operation (23

  19. Anti-Cataract Potential of Heliotropium indicum Linn on Galactose-Induced Cataract in Sprague-Dawley Rats.

    Science.gov (United States)

    Kyei, Samuel; Koffuor, George A; Ramkissoon, Paul; Abu, Emmanuel K; Sarpong, Josephine F

    2017-03-01

    To evaluate the anti-cataract potential of an aqueous whole plant extract of Heliotropium indicum (HIE) on galactose-induced cataract in Sprague-Dawley rats. Cataract scores were recorded in 3-week-old Sprague-Dawley rats in which cataract was being induced by an oral administration of 1500 mgkg-1 galactose twice daily for 4 weeks, and concurrently being treated with 30, 100, or 300 mgkg-1 HIE daily over the induction period. Fasting blood glucose was monitored at weekly intervals. Changes in body weight as well as total lens protein, lens glutathione, and superoxide dismutase (SOD) were determined initially, and at the end of the experimental period. Crystalline lens weight-to-body-weight ratio was also determined for the various treatment groups at the end of the experimental period. Preliminary phytochemical screening, total antioxidant capacity, and reducing power assays were conducted on HIE. The 30 and 100 mgkg-1 HIE-treated rats recorded significantly lower (p ≤ 0.05-0.001) cataract scores (indicating very significant delays in cataractogenesis by the 3rd and 4th weeks of treatment) and blood glucose levels. Rats with delayed cataractogenesis also exhibited significant (p ≤ 0.05-0.001) weight gain, and reduction in lens weight. Total lens proteins glutathione and SOD levels in the crystalline lens were also significantly preserved (p ≤ 0.01-0.001). HIE showed substantial antioxidant capacity and reducing power. The aqueous whole plant extract of Heliotropium indicum delays cataractogenesis at an optimum dose of 30 mgkg-1 in Sprague-Dawley rats.

  20. Pattern of presentation of pediatric cataract in tribes of hills of Western India: A hospital-based retrospective study at Global Hospital Institute of Ophthalmology, Mount Abu

    Directory of Open Access Journals (Sweden)

    Amit Mohan

    2017-01-01

    Full Text Available Context: Congenital cataract is a priority of Vision 2020: the right to sight, the global initiative to reduce the world's burden of avoidable blindness because it is an important treatable cause of visual physically challenged in childhood worldwide. Prevention and treatment require information about etiology that is currently unavailable for many regions of the world. From an epidemiologic study, the causative factors of pediatric cataract can be identified. Aims: This study aims to determine causes of childhood cataracts and to identify the preventable factors in tribes of hilly areas of Western India. Settings and Design: The present study is a hospital-based retrospective study. Materials and Methods: A retrospective study was conducted after reviewing the details of 165 patients of pediatric cataract aged between 3 months and 15 years who underwent cataract surgery in our institute from April 2011 to March 2014. A team of ophthalmologists and pediatricians attached to the center examined all the patients preoperatively. The type of cataract was determined using slit lamp biomicroscopy or operating microscope. Results: Nontraumatic cataract was 72.1% and traumatic cataract was 27.9%. Nontraumatic cataract includes hereditary (10.1%, rubella (5.0%, secondary (16.8%, and idiopathic (68.1%. In nontraumatic cataract group, 66 patients had bilateral cataract and 53 had unilateral cataract. Traumatic cataract was the most common in the age group of 6–10 years and most common cause of trauma is thorn (23.9% followed by stone (21.7%, crackers (17.4%, wood stick (13%, finger (4.3%, chemical injury (4.3%, needle (4.3%, wire (2.2%, and others (8.7%. Conclusions: About 5% of nontraumatic bilateral cataracts in hills of Western India are due to rubella. An awareness program for precaution during pregnancy and immunization against rubella is needed to prevent it. School children must be educated for factors causing traumatic cataract and need

  1. Impact of cataract surgery on vision-related life performances: the usefulness of Real-Life Vision Test for cataract surgery outcomes evaluation.

    Science.gov (United States)

    Ni, W; Li, X; Hou, Z; Zhang, H; Qiu, W; Wang, W

    2015-12-01

    Real-Life Vision Test (RLVT) is a newly developed performance-based measures of functional vision. This present study is designed to determine whether it could be a meaningful assessment for cataract surgery outcomes evaluation. Age-related cataract patients (56) who scheduled for bilateral cataract surgery and 44 age-matched controls were evaluated by four types of measurements: (1) demographic, medical, cognitive and depressive evaluation, and the reaction time testing; (2) clinical measures (visual acuity, contrast sensitivity, stereopsis, and color perception); (3) the 25-item National Eye Institute's Visual Functioning Questionnaire (NEI-VFQ); (4) the RLVT. Spearman's coefficients and multiple regression analysis were conducted to investigate the relationship among RLVT, clinical measures, and self-report assessment of visual function. The results of RLVT, clinical measures, and NEI-VFQ total scores were improved significantly after cataract surgery. There were no differences between control subjects and post-surgery patients with respect to NEI-VFQ-25 total scores, self-rating depression scale scores and three tasks of RLVT. Change of RLVT was significantly associated with the change of clinical measures in the cataract group. Multiple regression analysis demonstrated that change of distance, intermediate, and near visual acuity, and binocular contrast sensitivity were significant predictors of improvements of RLVT. Cataract surgery could improve real-world visual ability effectively for cataract patients. Our study highlights the potential usefulness of RLVT as an adjunct to the current outcomes evaluation system for cataract surgery. The use of RLVT combined with clinical and self-survey methods may be the comprehensive strategy to manifest the impact of cataract surgery on patients' overall vision-related quality of life.

  2. Melatonin mitigate cerebral vasospasm after experimental subarachnoid hemorrhage: a study of synchrotron radiation angiography

    Science.gov (United States)

    Cai, J.; He, C.; Chen, L.; Han, T.; Huang, S.; Huang, Y.; Bai, Y.; Bao, Y.; Zhang, H.; Ling, F.

    2013-06-01

    Cerebral vasospasm (CV) after subarachnoid hemorrhage (SAH) is a devastating and unsolved clinical issue. In this study, the rat models, which had been induced SAH by prechiasmatic cistern injection, were treated with melatonin. Synchrotron radiation angiography (SRA) was employed to detect and evaluate CV of animal models. Neurological scoring and histological examinations were used to assess the neurological deficits and CV as well. Using SRA techniques and histological analyses, the anterior cerebral artery diameters of SAH rats with melatonin administration were larger than those without melatonin treatment (p melatonin were less than those without melatonin treatment (p melatonin could mitigate CV after experimental SAH.

  3. It's All Relative: A Validation of Radiation Quality Comparison Metrics

    Science.gov (United States)

    Chappell, Lori J.; Milder, Caitlin M.; Elgart, S. Robin; Semones, Edward J.

    2017-01-01

    The difference between high-LET and low-LET radiation is quantified by a measure called relative biological effectiveness (RBE). RBE is defined as the ratio of the dose of a reference radiation to that of a test radiation to achieve the same effect level, and thus, is described either as an iso-effector dose-to-dose ratio. A single dose point is not sufficient to calculate an RBE value; therefore, studies with only one dose point usually calculate an effect-to-effect ratio. While not formally used in radiation protection, these iso-dose values may still be informative. Shuryak, et al 2017 investigated the use of an iso-dose metric termed "radiation effects ratio" (RER) and used both RBE and RER to estimate high-LET risks. To apply RBE or RER to risk prediction, the selected metric must be uniquely defined. That is, the calculated value must be consistent within a model given a constant set of constraints and assumptions, regardless of how effects are defined using statistical transformations from raw endpoint data. We first test the RBE and the RER to determine whether they are uniquely defined using transformations applied to raw data. Then, we test whether both metrics can predict heavy ion response data after simulated effect size scaling between human populations or when converting animal to human endpoints.

  4. Assessing the changes in the biomechanical properties of the crystalline lens induced by cold cataract with air-pulse OCE

    Science.gov (United States)

    Wu, C.; Singh, M.; Liu, C.-H.; Han, Z.; Li, J.; Raghunathan, R.; Larin, K. V.

    2015-11-01

    A cataract is the increase in opacity of the crystalline lens that can pathologically degrade visual acuity. In this study, we utilized a phase-sensitive optical coherence elastography (OCE) system to study the effects of a cold cataract on the biomechanical properties of the porcine crystalline lens in vitro. The cold cataract was induced by placing the whole lens in a low temperature environment until the lens was obviously clouded. Air-pulse OCE measurements were conducted on 6 lenses before and after cold cataract induction. A low amplitude displacement (≤ 10 µm) was induced by a focused air-pulse and the temporal deformation profiles from the surface and within the lenses were analyzed. The results demonstrated that the stiffness of the porcine lens increased after induction of the cold cataract, and it demonstrated the feasibility of OCE to assess the biomechanical changes in the lens due to cataract.

  5. REVIEW OF CATARACT SURGERY FROM 1998 TO 2001 AT THE MURSKA SOBOTA GENERAL HOSPITAL EYE DEPARTMENT

    Directory of Open Access Journals (Sweden)

    Mitja Šterman

    2003-05-01

    Full Text Available Background. Cataract is a leading cause of a reversible blindness in a developed world. The number of cataract surgery procedures performed has been increasing. This study describes methods and cataract surgery quality in Pomurje region, Slovenia from 1998 to 2001, to identify the need for cataract surgical service in this region.Methods. For the purposes of this study, data from medical documentation of all 1182 cataract surgery procedures performed in Murska Sobota Eye Department from 1998 to 2001 were obtained.Results. The rate of cataract surgery has increased from 1.5 to 3.3 per 1000 inhabitants during the observed period. The percentage of glaucoma and diabetes in operated patients has grown in this period. Extracapsular cataract extraction has been replaced by phacoemulsification. In 2001, 95.5% of procedures was performed by phacoemulsification and in 99.0% of cases intraocular lenses were implanted during the surgery. The average pre-operative visual acuity was 0.05 in 1998, 0.11 in 1999, 0.16 in 2000 and 0.22 in 2001. The average waiting period for surgery was 3 months in 1998 and 16 months in 2001.Uncorrected post-operative visual acuity of 1.0 was achieved in 29% and in 50% surgical procedures in years of 1998 and 2001, respectively. The number of complications decreased.Conclusions. A number of cataract surgeries increased and their outcomes showed a considerable improvement. At the same time, real patient needs weren’t addressed as waiting time for surgery increased. Waiting time for surgery has increased. It is to be feared that the number of patients, waiting for the cataract surgery, will increase unless the number of procedures increases. The number of procedures allowed to be performed is too low compared to the number of patients with cataracts.

  6. Quality of care from the perspective of the cataract patient: QUOTE Cataract Questionnaire.

    NARCIS (Netherlands)

    Nijkamp, M.D.; Sixma, H.J.; Afman, H.; Hiddema, F.; Koopmans, S.A.; Borne, B. van den; Hendrikse, F.; Nuijts, R.M.M.A.

    2002-01-01

    PURPOSE: To examine the potential of a questionnaire (QUOTE Cataract) to measure quality of care from the perspective of cataract patients in quality-assurance or improvement programs. SETTING: Department of Ophthalmology, University Hospital Maastricht, Maastricht, University Hospital Groningen,

  7. Quality of care from the perspective of the cataract patient - QUOTE Cataract Questionnaire

    NARCIS (Netherlands)

    Nijkamp, MD; Sixma, HJ; Afman, H; Hiddema, F; Koopmans, SA; van den Borne, B; Hendrikse, F; Nuijts, RMMA

    2002-01-01

    Purpose: To examine the potential of a questionnaire (QUOTE Cataract) to measure quality of care from the perspective of cataract patients in quality-assurance or improvement programs. Setting. Department of Ophthalmology, University Hospital Maastricht, Maastricht, University Hospital Groningen,

  8. Experimental Observation of Direct Particle Acceleration by Stimulated Emission of Radiation

    Science.gov (United States)

    Banna, Samer; Berezovsky, Valery; Schächter, Levi

    2006-09-01

    We report the first experimental evidence for direct particle acceleration by stimulated emission of radiation. In the framework of this proof-of-principle experiment, a 45 MeV electron macrobunch was modulated by a high-power CO2 laser and then injected into an excited CO2 gas mixture. The emerging microbunches experienced a 0.15% relative change in the kinetic energy, in a less than 40 cm long interaction region. According to our experimental results, a fraction of these electrons have gained more than 200 keV each, implying that such an electron has undergone an order of magnitude of 2×106 collisions of the second kind.

  9. An experimental study of radiative fluxes in the south Bay of Bengal ...

    Indian Academy of Sciences (India)

    An inter- comparison experiment conducted at DS3 showed that the radiative fluxes measured by Kipp and Zonen, Albedo meter and net Pyrgeometer onboard SD and by Eppley radiometers onboard ORV Sagar Kanya (SK) are well matched. It may be mentioned that the measurements showed consistency and good ...

  10. [Experimental research on the electromagnetic radiation immunity of a kind of portable monitor].

    Science.gov (United States)

    Yuan, Jun; Xiao, Dongping; Jian, Xin

    2010-11-01

    The paper is focused on a kind of portable monitor that is widely used in military hospitals. In order to study the electromagnetic radiation immunity of the monitor, the experiments of electromagnetic radiation caused by radio frequency continuous wave in reverberation chamber and by ultra wide band (UWB) electromagnetic pulse have been done. The study results show that UWB electromagnetic pulse interferes observably the operating state of the monitor. It should be paid high attention to take protective measures. The monitor tested has some electromagnetic immunity ability for radio frequency continuous wave radiation. The frequent abnormal phenomena are baseline drift and waveform distortion. The electromagnetic sensitivity of the monitor is related to the frequency of interference source. The monitor tested is most sensitive to the frequency of 390 MHz.

  11. "Calibration" system for spectral measurements and its experimental results

    Science.gov (United States)

    Bruchkouskaya, Sviatlana I.; Katkovsky, Leonid V.; Belyaev, Boris I.; Malyshev, Vladislav B.

    2017-04-01

    "Calibration" system has been developed at A. N. Sevchenko Research Institute of Applied Physical Problems of the Belarusian State University. It was designed for measuring the characteristics of spectral reflectance of all types of natural surfaces (test sites) in ground conditions or on board of aircraft carriers and has the following components: - Photospectroradiometr (PhSR) of high resolution with a range of 400-900 nm, equipped with a digital time-lapse video system; - Two-channel modular spectroradiometer (TMS) with a range of 400-900 nm, designed for simultaneous measurements of reflected light brightness of the underlying surface and the incident radiation from the upper hemisphere; - Two portable spectroradiometers (PSR-700 and PSR-1300) with a spectral range 800-1500 nm; 1200-2500 nm; - Scanning solar spectropolarimeter (SSP-600) with a range of 350-950 nm for measurements of direct sunlight and scattered by the atmosphere at different angles; "Calibration" system provides spectral resolution of 5.2 nm in a range of 400-900 nm, 10 nm in a range of 800-1500 nm and 15 nm in a range of 1200-2500 nm. Measurements of the optical characteristics of solar radiation (for determining parameters of the atmosphere) and that of underlying surface are synchronous. There is also a set of special nozzles for measurements of spectral brightness coefficients, polarization characteristics and spectral albedo. Spectra and images are geotagged to the navigation data (time, GPS). For the measurements of spectral reflection dependencies within "Monitoring-SG" framework expeditions to the Kuril Islands, Kursk aerospace test site and Kamchatka Peninsula were conducted in 2015 and 2016. The spectra of different underlying surfaces have been obtained: soils, plants and water objects, sedimentary and volcanic rocks. These surveys are a valuable material for further researches and selection of test facilities for flight calibration of space imaging systems. Information obtained

  12. Radiation Preservation of Foods and Its Effect on Nutrients

    Science.gov (United States)

    Josephson, Edward S.; Thomas, Miriam H.

    1970-01-01

    Presents a discussion of (1) some possible applications of ionizing radiation to the treatment and preservation of food and (2) the effects of irradiation on nutrients such as proteins, fats, oils, carbohydrates and vitamins. The authors suggest that the irradiation process has great potential in food technology. Bibliography. (LC)

  13. Endothelial trauma in the surgery of cataract

    Directory of Open Access Journals (Sweden)

    Đurović Branislav M.

    2004-01-01

    Full Text Available Cataract surgery is most common in human surgery and comprises 80% of eye surgery programs. Owing to sophisticated technologies, it has become a routine surgery with lowered complications rate; hence, the functional outcome is more conditioned by operative trauma. The aim of this study was to demonstrate the significance of specular microscopy in the evaluation of operative trauma during extra-capsular cataract extraction (ECCE and phacoemulsification (P, in a controlled environment. The study included 100 consecutive patients who met the established criteria, and groups were formed according to the type of surgery by the assignment of successive numbers from a random number table. Examination and photographs of the corneal endothelium, as well as pachymetry were performed on Keeler-Konan Poclington Specular Microscope (KSP. The obtained results revealed significant dissimilarity in endothelial cell reduction (9.17% in group E, and 4.72% in group P, which generated statistically significant correlation of pre-operative and post-operative pachymetry in the group E (p=0.0004. On the basis of the results obtained by specular microscopy, it was concluded that under the same conditions phacoemulsification caused reduced operative trauma of the corneal endothelium.

  14. Comparison of a fast analytical model of radiation damage effects in CCDs with experimental tests

    Science.gov (United States)

    Prod'homme, Thibaut; Weiler, Michael; Brown, Scott W.; Short, Alexander D. T.; Brown, Anthony G. A.

    2010-07-01

    ESA's Gaia mission aims to create a complete and highly accurate stereoscopic map of the Milky Way. The stellar parallaxes will be determined at the micro-arcsecond level, as a consequence the measurement of the stellar image location on the CCD must be highly accurate. The solar wind protons will create charge traps in the CCDs of Gaia, which will induce large charge loss and distort the stellar images causing a degradation of the location measurement accuracy. Accurate modelling of the stellar image distortion induced by radiation is required to mitigate these effects. We assess the capability of a fast physical analytical model of radiation damage effects called the charge distortion model (CDM) to reproduce experimental data. To realize this assessment we developed a rigorous procedure that compares at the sub-pixel level the model outcomes to damaged images extracted from the experimental tests. We show that CDM can reproduce accurately up to a certain level the test data acquired on a highly irradiated device operated in time delay integration mode for different signal levels and different illumination histories. We discuss the potential internal and external factors that contributed to limit the agreement between the data and the charge distortion model. To investigate these limiting factors further, we plan to apply our comparison procedure on a synthetic dataset generated through detailed Monte-Carlo simulations at the CCD electrode level.

  15. Cataract treatment: must we remain blind to couching? | Okoye ...

    African Journals Online (AJOL)

    Aim: To highlight the persistence of couching as a treatment for cataract in our community and its attendant complications. Materials and Methods: Retrospective study, using hospital records of 9 patients who had undergone couching and presented at the eye clinic, University of Nigeria Teaching Hospital, Enugu between ...

  16. Experimental Investigation of Three Machine Learning Algorithms for ITS Dataset

    Science.gov (United States)

    Yearwood, J. L.; Kang, B. H.; Kelarev, A. V.

    The present article is devoted to experimental investigation of the performance of three machine learning algorithms for ITS dataset in their ability to achieve agreement with classes published in the biologi cal literature before. The ITS dataset consists of nuclear ribosomal DNA sequences, where rather sophisticated alignment scores have to be used as a measure of distance. These scores do not form a Minkowski metric and the sequences cannot be regarded as points in a finite dimensional space. This is why it is necessary to develop novel machine learning ap proaches to the analysis of datasets of this sort. This paper introduces a k-committees classifier and compares it with the discrete k-means and Nearest Neighbour classifiers. It turns out that all three machine learning algorithms are efficient and can be used to automate future biologically significant classifications for datasets of this kind. A simplified version of a synthetic dataset, where the k-committees classifier outperforms k-means and Nearest Neighbour classifiers, is also presented.

  17. Cataract surgery in the glaucoma patient

    OpenAIRE

    Kung, Jennifer S.; Daniel Y Choi; Cheema, Anjum S.; Kuldev Singh

    2015-01-01

    To summarize the role of cataract surgery in the glaucoma patient, in terms of the effect on intraocular pressure (IOP) as well as diagnostic and therapeutic considerations for those with both conditions. Recent evidence suggests that cataract extraction may produce a significant and sustained IOP reduction in individuals with open-angle glaucoma, ocular hypertension, and angle-closure glaucoma. Cataract removal may improve the practitioner's ability to interpret perimetric testing, and re-es...

  18. A Genome-Wide Association Study Provides New Evidence That CACNA1C Gene is Associated With Diabetic Cataract

    Science.gov (United States)

    Chang, Cheng; Zhang, Kaida; Veluchamy, Abirami; Hébert, Harry L.; Looker, Helen C.; Colhoun, Helen M.; Palmer, Colin N. A.; Meng, Weihua

    2016-01-01

    Purpose Diabetic cataract is one of the major eye complications of diabetes. It was reported that cataract occurs two to five times more frequently in patients with diabetes compared with those with no diabetes. The purpose of this study was to identify genetic contributors of diabetic cataract based on a genome-wide association approach using a well-defined Scottish diabetic cohort. Methods We adapted linked e-health records to define diabetic cataract. A diabetic cataract case in this study was defined as a type 2 diabetic patient who has ever been recorded in the linked e-health records to have cataracts in both eyes or who had previous cataract extraction surgeries in at least one eye. A control in this study was defined as a type 2 diabetic individual who has never been diagnosed as cataract in the linked e-health records and had no history of cataract surgeries. A standard genome-wide association approach was applied. Results Overall, we have 2341 diabetic cataract cases and 2878 controls in the genetics of diabetes audit and research in Tayside Scotland (GoDARTS) dataset. We found that the P value of rs2283290 in the CACNA1C gene was 8.81 × 10−10, which has reached genome-wide significance. We also identified that the blood calcium level was statistically different between diabetic cataract cases and controls. Conclusions We identified supporting evidence that CACNA1C gene is associated with diabetic cataract. The role of calcium in the cataractogenesis needs to be reevaluated in future studies. PMID:27124316

  19. Cataract surgery after refractive surgery.

    Science.gov (United States)

    Naseri, Ayman; McLeod, Stephen D

    2010-01-01

    To review recent contributions addressing the challenge of intraocular lens (IOL) calculation in patients undergoing cataract extraction following corneal refractive surgery. Although several articles have provided excellent summaries of IOL selection in patients wherein prerefractive surgery data are available, numerous authors have recently described approaches to attempt more accurate IOL power calculations for patients who present with no reliable clinical information regarding their refractive history. Additionally, results have been reported using the Scheimpflug camera system to measure corneal power in an attempt to resolve the most important potential source of error for IOL determination in these patients. IOL selection in patients undergoing cataract surgery after corneal refractive surgery continues to be a challenging and complex issue despite numerous strategies and formulas described in the literature. Current focus seems to be directed toward approaches that do not require preoperative refractive surgery information. Due to the relative dearth of comparative clinical outcomes data, the optimal solution to this ongoing clinical problem has yet to be determined. Until such data are available, many cataract surgeons compare the results of multiple formulas to assist them in IOL selection for these patients.

  20. Patient satisfaction with cataract surgery

    Directory of Open Access Journals (Sweden)

    Wasfi Ehab I

    2008-10-01

    Full Text Available Abstract Introduction Measuring the patient satisfaction is a very important issue that will help very much in improving the service provided to patients and improve the level of satisfaction. Aim To evaluate patient satisfaction with the cataract surgery service and identify any areas for improvement, determination of patient satisfaction with referral, out-patient consultation, pre-assessment clinic, surgery and post-operative care, also to report patients' comments relating to improvement in service provision. Methodology A retrospective study was undertaken for 150 patients underwent cataract surgery at Barrow General Hospital, UK, the survey sample was by postal questionnaires. We collected our data from the theatre lists for a period of 4 month. Results This study included 150 patients; the response rate was (72% 108 patients, Most patients were referred from their general practitioner 86.1%, 93 (86.1% patients were happy with the time interval from seeing their GP to eye clinic. In the eye out patient department many factors significantly affected the level of patient satisfaction, in general the more information provided for the patient the more the satisfaction. Conclusion Patient satisfaction is on important health outcome old understanding both the domains of satisfaction as well as their relative importance to patients is necessary to improve the overall quality of patient care. Meeting the doctor, presenting all relevant information and giving printed information are very important factors in improving the patient's satisfaction with cataract surgery.

  1. How to prevent endophthalmitis in cataract surgeries?

    Directory of Open Access Journals (Sweden)

    Kelkar Aditya

    2008-01-01

    Full Text Available Postoperative endophthalmitis is a very devastating complication and every step should be taken to reduce its occurrence. Unattended air conditioning filter systems are often the culprits and regular maintenance of the filters is of paramount importance. Shedders of pathogenic organisms amongst the theater personnel should be identified by regular screening and should be promptly treated. In addition to the use of Povidone iodine 5% solution in the conjunctival sac few minutes prior to surgery, proper construction of wound, injectable intraocular lenses, use of prophylactic intracameral antibiotics or prophylactic subconjunctival antibiotic injection at the conclusion of cataract surgery, placing a patch after the surgery for at least 4 h and initiating topical antibiotics from the same day of surgery helps to lower the frequency of postoperative endophthalmitis. Intraoperative posterior capsule rupture and anterior vitrectomy are risk factors for acute endophthalmitis, and utmost care to prevent posterior capsular rent should be taken while performing cataract surgery. Also, in case of such complication, these patients should be closely monitored for early signs of endophthalmitis in the postoperative period. In the unfortunate event of endophthalmitis the diagnosis should be prompt and treatment must be initiated as early as possible.

  2. How to prevent endophthalmitis in cataract surgeries?

    Science.gov (United States)

    Kelkar, Jai; Amuaku, Winfried; Kelkar, Uday; Shaikh, Aarofil

    2008-01-01

    Postoperative endophthalmitis is a very devastating complication and every step should be taken to reduce its occurrence. Unattended air conditioning filter systems are often the culprits and regular maintenance of the filters is of paramount importance. Shedders of pathogenic organisms amongst the theater personnel should be identified by regular screening and should be promptly treated. In addition to the use of Povidone iodine 5% solution in the conjunctival sac few minutes prior to surgery, proper construction of wound, injectable intraocular lenses, use of prophylactic intracameral antibiotics or prophylactic subconjunctival antibiotic injection at the conclusion of cataract surgery, placing a patch after the surgery for at least 4 h and initiating topical antibiotics from the same day of surgery helps to lower the frequency of postoperative endophthalmitis. Intraoperative posterior capsule rupture and anterior vitrectomy are risk factors for acute endophthalmitis, and utmost care to prevent posterior capsular rent should be taken while performing cataract surgery. Also, in case of such complication, these patients should be closely monitored for early signs of endophthalmitis in the postoperative period. In the unfortunate event of endophthalmitis the diagnosis should be prompt and treatment must be initiated as early as possible. PMID:18711270

  3. A broadly applicable surgical teaching method: evaluation of a stepwise introduction to cataract surgery.

    Science.gov (United States)

    Kloek, Carolyn E; Borboli-Gerogiannis, Sheila; Chang, Kenneth; Kuperwaser, Mark; Newman, Lori R; Lane, Anne Marie; Loewenstein, John I

    2014-01-01

    Although cataract surgery is one of the most commonly performed surgeries in the country, it is a microsurgical procedure that is difficult to learn and to teach. This study aims to assess the effectiveness of a new method for introducing postgraduate year (PGY)-3 ophthalmology residents to cataract surgery. Hospital-based ophthalmology residency program. Retrospective cohort study. PGY-3 and PGY-4 residents of the Harvard Medical School Ophthalmology Residency from graduating years 2010 to 2012. In July 2009, a new method of teaching PGY-3 ophthalmology residents cataract surgery was introduced, which was termed "the stepwise introduction to cataract surgery." This curriculum aimed to train residents to perform steps of cataract surgery by deliberately practicing each of the steps of surgery under a structured curriculum with faculty feedback. Assessment methods included surveys administered to the PGY-4 residents who graduated before the implementation of these measures (n = 7), the residents who participated in the first and second years of the new curriculum (n = 16), faculty who teach PGY-4 residents cataract surgery (n = 8), and review of resident Accreditation Council for Graduate Medical Education surgical logs. Resident survey response rate was 100%. Residents who participated in the new curriculum performed more of each step of cataract surgery in the operating room, spent more time practicing each step of cataract surgery on a cataract surgery simulator during the PGY-3 year, and performed more primary cataract surgeries during the PGY-3 year than those who did not. Faculty survey response rate was 63%. Faculty noted an increase in resident preparedness following implementation of the new curriculum. There was no statistical difference between the precurriculum and postcurriculum groups in the percentage turnover of cataracts for the first 2 cataract surgery rotations of the PGY-4 year of training. The introduction of cataract surgery to PGY-3 residents

  4. Black carbon vertical profiles strongly affect its radiative forcing uncertainty

    Directory of Open Access Journals (Sweden)

    B. H. Samset

    2013-03-01

    Full Text Available The impact of black carbon (BC aerosols on the global radiation balance is not well constrained. Here twelve global aerosol models are used to show that at least 20% of the present uncertainty in modeled BC direct radiative forcing (RF is due to diversity in the simulated vertical profile of BC mass. Results are from phases 1 and 2 of the global aerosol model intercomparison project (AeroCom. Additionally, a significant fraction of the variability is shown to come from high altitudes, as, globally, more than 40% of the total BC RF is exerted above 5 km. BC emission regions and areas with transported BC are found to have differing characteristics. These insights into the importance of the vertical profile of BC lead us to suggest that observational studies are needed to better characterize the global distribution of BC, including in the upper troposphere.

  5. Radiation Shielding Materials Containing Hydrogen, Boron, and Nitrogen: Systematic Computational and Experimental Study. Phase I

    Science.gov (United States)

    Thibeault, Sheila A.; Fay, Catharine C.; Lowther, Sharon E.; Earle, Kevin D.; Sauti, Godfrey; Kang, Jin Ho; Park, Cheol; McMullen, Amelia M.

    2012-01-01

    The key objectives of this study are to investigate, both computationally and experimentally, which forms, compositions, and layerings of hydrogen, boron, and nitrogen containing materials will offer the greatest shielding in the most structurally robust combination against galactic cosmic radiation (GCR), secondary neutrons, and solar energetic particles (SEP). The objectives and expected significance of this research are to develop a space radiation shielding materials system that has high efficacy for shielding radiation and that also has high strength for load bearing primary structures. Such a materials system does not yet exist. The boron nitride nanotube (BNNT) can theoretically be processed into structural BNNT and used for load bearing structures. Furthermore, the BNNT can be incorporated into high hydrogen polymers and the combination used as matrix reinforcement for structural composites. BNNT's molecular structure is attractive for hydrogen storage and hydrogenation. There are two methods or techniques for introducing hydrogen into BNNT: (1) hydrogen storage in BNNT, and (2) hydrogenation of BNNT (hydrogenated BNNT). In the hydrogen storage method, nanotubes are favored to store hydrogen over particles and sheets because they have much larger surface areas and higher hydrogen binding energy. The carbon nanotube (CNT) and BNNT have been studied as potentially outstanding hydrogen storage materials since 1997. Our study of hydrogen storage in BNNT - as a function of temperature, pressure, and hydrogen gas concentration - will be performed with a hydrogen storage chamber equipped with a hydrogen generator. The second method of introducing hydrogen into BNNT is hydrogenation of BNNT, where hydrogen is covalently bonded onto boron, nitrogen, or both. Hydrogenation of BN and BNNT has been studied theoretically. Hyper-hydrogenated BNNT has been theoretically predicted with hydrogen coverage up to 100% of the individual atoms. This is a higher hydrogen content

  6. An Autonomous System for Experimental Evolution of Microbial Cultures: Test Results Using Ultraviolet-C Radiation and Escherichia Coli.

    Science.gov (United States)

    Ouandji, Cynthia; Wang, Jonathan; Arismendi, Dillon; Lee, Alonzo; Blaich, Justin; Gentry, Diana

    2017-01-01

    At its core, the field of microbial experimental evolution seeks to elucidate the natural laws governing the history of microbial life by understanding its underlying driving mechanisms. However, observing evolution in nature is complex, as environmental conditions are difficult to control. Laboratory-based experiments for observing population evolution provide more control, but manually culturing and studying multiple generations of microorganisms can be time consuming, labor intensive, and prone to inconsistency. We have constructed a prototype, closed system device that automates the process of directed evolution experiments in microorganisms. It is compatible with any liquid microbial culture, including polycultures and field samples, provides flow control and adjustable agitation, continuously monitors optical density (OD), and can dynamically control environmental pressures such as ultraviolet-C (UV-C) radiation and temperature. Here, the results of the prototype are compared to iterative exposure and survival assays conducted using a traditional hood, UV-C lamp, and shutter system.

  7. The morphology and natural history of childhood cataracts.

    Science.gov (United States)

    Amaya, Luis; Taylor, David; Russell-Eggitt, Isabelle; Nischal, Ken K; Lengyel, Dora

    2003-01-01

    The morphology of congenital cataract reflects a combination of the timing and nature of the cause, the anatomy of the lens including its capsule, its development, and changes that take place with time. Morphology may variably affect prognosis, give a clue to the etiology and the age of onset and, in an isolated case, sometimes suggest heritability. The spectrum of morphological variations is enormous and can be complex. A comprehensive approach is to classify the variations according to the area of the lens involved, and sub-dividing them by a detailed description of the shape and appearance. Each specific morphological type is then analyzed determining the etiology, visual prognosis, and management. The use of gene markers has allowed many of these variations to be identified and categorized. Cataracts in childhood can involve the whole lens, in which case they are called total, Morgagnian, or disk-like. They can affect only the center of the lens: lamellar, nuclear, oil droplet, cortical, or coronary. They can be anterior: anterior polar, anterior subcapsular, or anterior lenticonus. The posterior aspect of the lens can also be affected in different fashions: Mittendorf's dot, posterior lenticonus, posterior cortical cataracts, or posterior subcapsular. There are five more forms that must be described separately: punctuate lens opacities, sutural cataracts, coralliform or crystalline, wedge-shaped, and persistent hyperplastic primary vitreous.

  8. Injury Based on Its Study in Experimental Models

    Directory of Open Access Journals (Sweden)

    M. Mendes-Braz

    2012-01-01

    Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

  9. Radiation protection, radioactive waste management and site monitoring at the nuclear scientific experimental and educational centre IRT-Sofia at INRNE-BAS.

    Science.gov (United States)

    Mladenov, Al; Stankov, D; Nonova, Tz; Krezhov, K

    2014-11-01

    This article identifies important components and describes the safe practices in implementing radiation protection and radioactive waste management programmes, and in their optimisation at the Nuclear Scientific Experimental and Educational Centre with research reactor IRT at INRNE-BAS. It covers the instrumentation and personal protective equipment and organisational issues related to the continuous site monitoring. The reactor is under major reconstruction and the measures applied to radiation monitoring of environment and working area focused on restricting the radiation exposure of the staff as well as compliance with international good practices related to the environmental and public radiation safety requirements are also addressed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. The clinical utility of new combination phenylephrine/ketorolac injection in cataract surgery

    Directory of Open Access Journals (Sweden)

    Lawuyi LE

    2015-07-01

    Full Text Available Lola Elizabeth Lawuyi, Avinash Gurbaxani Moorfields Eye Hospital Dubai, Dubai, UAE Abstract: The maintenance of mydriasis throughout cataract extraction surgery and the control of ocular inflammation are crucial for successful surgical outcomes. The development of miosis during cataract surgery compromises the visualization of the surgical field and working space for surgeons. This may lead to complications that include posterior capsular tear and associated vitreous loss, longer surgical time, and postoperative inflammation. Postoperative inflammation is often uncomfortable and frustrating for patients. It causes pain, redness, and photophobia. This compromises the best-uncorrected vision following surgery and often leads to multiple clinic visits. This article examines the literature published on the current treatments used to manage mydriasis, pain, and inflammation in cataract extraction surgery. Combination phenylephrine/ketorolac injection offers an exciting new class of medication for use in cataract surgery. With the recent approval of Omidria™ (combination of phenylephrine 1% and ketorolac 0.3% by the US Food and Drug Administration (FDA for intraocular use, we review the clinical utility of this new combination injection in cataract surgery. PubMed, MEDLINE, and conference proceedings were searched for the relevant literature using a combination of the following search terms: cataract extraction surgery, pupil dilation (mydriasis, miosis, phenylephrine, ketorolac, Omidria™, intracameral mydriatic. Relevant articles were reviewed and their references checked for further relevant literature. All abstracts were reviewed and full texts retrieved where available. Keywords: cataract extraction surgery, ketorolac, mydriasis, miosis, Omidria™, phenylephrine

  11. Alterations of Serum Electrolytes and Malondialdehyde in Cataract Patients Attending General Hospital Owerri

    Directory of Open Access Journals (Sweden)

    Nnodim Johnkennedy

    2015-07-01

    Full Text Available Aim: This study was carried out to determine the level of serum electrolyte and malondialdehyde in cataract patients. Material and Methods: 80 cataract patients within the age of 55 years to 75 years attending General Hospital Owerri for routine blood glucose check were used in this study. Also 80 apparently healthy subjects without cataract within the age of 55 years and 75 years were used as control. The level of electrolytes particularly sodium and potassium were measured. The levels of glucose, urea, creatinine were measured in order to rule out diabetes and kidney malfunction respectively in both study and control groups. Result:It was observed that the level of sodium and Malondialdehyde (MDA were significantly increased in cataract patients when compared with controls (p0.05. Conclusion: This observation shows that increased sodium level in cataract patients could probably result in elevation of aqueous humor of the lens which contributes to osmotic disorder across the lens membrane. This could aggravate the progression of cataract as a result of MDA elevation. Therefore, salt restricted diet could be beneficial to cataract patients by preventing electrolyte disorder, hypernatremia and maintain the electrolyte balance.

  12. The effect of cataract surgery on salivary melatonin and sleep quality in aging people.

    Science.gov (United States)

    Shenshen, Yan; Minshu, Wang; Qing, Yuan; Yang, Liu; Suodi, Zhai; Wei, Wang

    2016-01-01

    Blue light plays an important role in circadian photoentrainment by stimulating the melanopsin-expressing photosensitive retinal ganglion cells. Age-related cataract causes progressive loss of blue light transmission, which may lead to changes in circadian rhythm and sleep quality. In theory, increased light transmission by cataract surgery may improve circadian misalignment and sleep quality, while the effect of cataract surgery on circadian rhythm is not well understood. In this study, we assessed 30 binocular age-related nuclear cataract patients (aged 72.5 ± 7.2, 16 female) who were eligible for cataract surgery. All the patients underwent phacoemulsification cataract extraction and neutral ultraviolet-only blocking intraocular lens (IOLs) implantation. Visual functions including best-corrected visual acuity (BCVA), color perception and dark adaptation were assessed. Salivary samples were collected at 1-hour interval from 19:00 to 23:00 48 hours before and after surgery. Salivary melatonin concentration was measured and dim light melatonin onset (DLMO) was calculated subsequently. Sleep quality and daytime alertness were assessed before and a month after surgery using Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). All the operated eyes demonstrated significant improvements in BCVA, color perception and dark adaptation after cataract surgery. Salivary melatonin concentration at 23:00 was significantly increased after surgery (P blue-light transmission; consequently, it may lead to the increase in nighttime melatonin concentration and improvement in sleep quality as well as daytime alertness.

  13. Investigation of attributes which guide choice in cataract surgery services in urban Sydney, Australia.

    Science.gov (United States)

    Gilbert, Celeste; Keay, Lisa; Palagyi, Anna; Do, Vu Quang; McCluskey, Peter; White, Andrew; Carnt, Nicole; Stapleton, Fiona; Laba, Tracey-Lea

    2018-01-17

    It is critical to consult patients to develop patient-centred cataract surgery care. We aimed to identify attributes patients consider when making decisions about cataract surgery in an Australian context, where both publicly and privately funded surgery are available. This is the first step in investigating how decisions are made about cataract surgery services. This observational qualitative study was undertaken in two public hospitals and one private practice in Sydney, Australia. The study involved 19 women and men with age-related cataracts and no previous cataract surgery, aged > 18 years, able to speak conversational English or Mandarin. A multi-stage attribute development process was followed, including: literature review, semi-structured interviews with surgery candidates in three eye clinics, and review by an expert panel. The main outcome measures were primary attributes for making choices about cataract surgery. Wait time, cost, institutional reputation, surgeon experience and travel time were identified as principal attributes; lower value was placed on consultation length and accessibility. Non-English speaking participants indicated greater interest in pre-operative information than English speakers, but expressed trust in the Australian healthcare system. Findings suggest individuals prioritise attributes which consume time or incur costs when accessing care (wait time, cost and travel time). They also consider factors associated with the outcome of their cataract surgery (surgeon experience and institutional reputation). Similar to other decision-making processes, patients are likely to trade between these different attributes depending on their personal preferences and circumstances. © 2018 Optometry Australia.

  14. A laboratory experimental setup for photo-absorption studies using synchrotron radiation

    CERN Document Server

    Shastri, A; Saraswati, P; Sunanda, K

    2002-01-01

    The photophysics beamline, which is being installed at the 450 MeV Synchrotron Radiation Source (SRS), Indus-l, is a medium resolution beamline useful for a variety of experiments in the VUV region viz. 500-2000 A. One of the major applications of this beamline is gas-phase photo-absorption studies. An experimental set up to be used for these experiments was designed, developed and tested in our laboratory. The setup consists of a high vacuum absorption cell, 1/4 m monochromator and detection system. For the purpose of testing, xenon and tungsten continuum sources were used and absorption spectra were recorded in the UV region. This setup was used to record the absorption spectrum of a few molecules like acetone, ammonia, benzene, formaldehyde and acetaldehyde in order to evaluate the performance of the experimental system which will subsequently be used with the photophysics beamline. Details of the design, fabrication and testing of the absorption cell and experimental procedures are presented in this repor...

  15. Dietary histidine requirement to reduce the risk and severity of cataracts is higher than the requirement for growth in Atlantic salmon smolts, independently of the dietary lipid source.

    Science.gov (United States)

    Remø, S C; Hevrøy, E M; Olsvik, P A; Fontanillas, R; Breck, O; Waagbø, R

    2014-05-28

    The present study was carried out to investigate whether the dietary histidine requirement to reduce cataract development is higher than that for growth in Atlantic salmon smolts (Salmo salar L.) after seawater transfer and whether dietary vegetable oils contribute to cataractogenesis. Duplicate groups of salmon smolts were fed ten experimental diets with either fish oil (FO) or a vegetable oil (VO) mix replacing 70 % FO and histidine at five target levels (10, 12, 14, 16 and 18 g His/kg diet) for 13 weeks after seawater transfer. The VO diet-fed fish exhibited somewhat inferior growth and feed intakes compared with the FO diet-fed fish, irrespective of the dietary histidine concentration. Both cataract prevalence and severity were negatively correlated with the dietary histidine concentration, while lens N-acetyl-histidine (NAH) concentrations were positively correlated with it. The fatty acid profiles of muscle, heart and lens reflected that of the dietary oils to a descending degree and did not affect the observed cataract development. Muscle, heart and brain histidine concentrations reflected dietary histidine concentrations, while the corresponding tissue imidazole (anserine, carnosine and NAH) concentrations appeared to saturate differently with time. The expression level of liver histidase was not affected by the dietary histidine concentration, while the liver antioxidant response was affected in the VO diet-fed fish on a transcriptional level. The lowest severity of cataracts could be achieved by feeding 13·4 g His/kg feed, independently of the dietary lipid source. However, the present study also suggests that the dietary histidine requirement to minimise the risk of cataract development is 14·4 g His/kg feed.

  16. Irrigation dynamic pressure-assisted hydrodissection during cataract surgery

    Directory of Open Access Journals (Sweden)

    Masuda Y

    2017-02-01

    Full Text Available Yoichiro Masuda,1 Hisaharu Iwaki,2 Noriko Kato,1 Genichiro Takahashi,1 Kotaro Oki,3 Hiroshi Tsuneoka4 1Department of Ophthalmology, The Jikei University, Katsushika Medical Center, 2Iwaki Eye Clinic, 3Oki Eye Surgery Center, 4Department of Ophthalmology, The Jikei University, School of Medicine, Tokyo, Japan Abstract: The irrigation dynamic pressure-assisted hydrodissection technique (irrigation-hydro [iH] does not require performing manual hydrodissection using a syringe and cannula to achieve cortical-capsular cleavage during cataract surgery. Since the iH technique uses the phaco tip to intentionally vacuum the intraocular fluid in order to induce the irrigation dynamic pressure for cortical-capsular cleavage, there is a reduction in the intraocular pressure (IOP from the bottle-height-dependent hydrostatic pressure. Thus, since the peak irrigation pressure derived from the phaco tip sleeve will be limited by the height of the irrigation fluid bottle, this is advantageous in helping to avoid excessively high IOP during cortical-capsular hydrodissection. Using this technique, we were able to effectively perform phacoemulsification without complications in 607 of 609 cataract eyes. Our findings show that utilization of the iH technique would be of benefit to patients, as it prevents high-pressure hydrodissection-related complications, such as capsular block syndrome and tears in the anterior hyaloid membrane during cataract surgery. Keywords: cataract surgery, hydrodissection, irrigation pressure, hydrodissection-related complication, capsular block syndrome, anterior hyaloid membrane tear, FLACS

  17. Treatment of congenital aniridia associated with subluxated infantile cataract.

    Science.gov (United States)

    Jusufovic, Vahid; Cabric, Emir; Popovic-Beganovic, Allen; Musanovic, Zlatko; Zvornicanin, Jasmin

    2014-01-01

    A 5 year old boy was presented at Eye clinic University clinical center Tuzla with congenital aniridia in both eyes. Clinical examination revealed visual acuity of 0.08 without correction in right and 0.7 with -5.0 Dsph and -1.0 Dcyl Axx 109 degrees in left eye. Opthalmologic examination showed bilateral aniridia associated with moderate cataract in the right and incipient cataract in the left eye. In the right eye, zonular weakness with incipient capsular displacement and esotropia of delta6 degrees, were noted. The patient underwent phacoemulsification, implantation of capsular tension ring and Artificial Iris implant in the capsular bag. Phacoemulsification went uneventful and early postoperative recovery was successful with no signs of aniridia-associated keratopathy development and normal values of intra ocular pressure. Patient was not motivated for operation of the left eye and it was corrected with soft contact lens. Six month after the operation visual acuity in the right eye improved to 0.9 with +1.25 Dsph and maintained stable in left eye, with complete elimination of esotropia and signs of binocular vision restoration. Small incision cataract extraction with IOL and Artificial Iris implantation in one procedure can be used to correct congenital aniridia and cataract with significant visual function improvement.

  18. Hyperferritinaemia-cataract syndrome: Worldwide mutations and phenotype of an increasingly diagnosed genetic disorder

    OpenAIRE

    Millonig Gunda; Muckenthaler Martina U; Mueller Sebastian

    2010-01-01

    Abstract The hereditary hyperferritinaemia-cataract syndrome (HHCS) is characterised by an autosomal dominant cataract and high levels of serum ferritin without iron overload. The cataract develops due to L-ferritin deposits in the lens and its pulverulent aspect is pathognomonic. The syndrome is caused by mutations within the iron-responsive element of L-ferritin. These mutations prevent efficient binding of iron regulatory proteins 1 and 2 to the IRE in L-ferritin mRNA, resulting in an unle...

  19. Cataract and barriers to cataract surgery in a US Hispanic population: Proyecto VER.

    Science.gov (United States)

    Broman, Aimee Teo; Hafiz, Gulnar; Muñoz, Beatriz; Rodriguez, Jorge; Snyder, Robert; Klein, Ronald; West, Sheila K

    2005-09-01

    To report the prevalence of visually significant cataract and cataract surgery and to determine demographic and socioeconomic factors that influence use of cataract surgery in a US Hispanic population. Proyecto VER is a population-based study of Hispanic individuals, 40 years or older, living in southern Arizona. Visual acuity was measured monocularly, and a dilated ophthalmic examination was performed to determine lens opacities. Visually significant cataract was defined as severe levels of opacity and acuity worse than 20/40. Risk factors were compared between those who obtained cataract surgery in the past and those having visually significant cataract. A majority of the 4774 participants in this study were of Mexican descent; 2.8% had visually significant cataract and 5.1% had undergone bilateral cataract surgery. Among those currently or previously needing surgery, having medical insurance (odds ratio, 2.88; P<.001) and speaking English (odds ratio, 1.80; P = .04) were significantly associated with having obtained surgery in the past. Visually significant cataract appears to be high among US Hispanic individuals of Mexican descent, as evidenced by rates of cataract and cataract surgery. Language and financial barriers in this population impede access to surgery. Further work to remove these barriers and provide sight restoration is warranted among Hispanic individuals of Mexican descent living in the United States.

  20. Exposure to electromagnetic fields (non-ionizing radiation) and its relationship with childhood leukemia: A systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Calvente, I.; Fernandez, M.F. [Laboratory of Medical Investigations, San Cecilio University Hospital, CIBER de Epidemiologia y Salud Publica (CIBERESP) (Spain); Department of Radiology, University of Granada, Granada (Spain); Villalba, J. [Department of Radiology, University of Granada, Granada (Spain); Olea, N. [Laboratory of Medical Investigations, San Cecilio University Hospital, CIBER de Epidemiologia y Salud Publica (CIBERESP) (Spain); Department of Radiology, University of Granada, Granada (Spain); Nunez, M.I., E-mail: isabeln@ugr.es [Department of Radiology, University of Granada, Granada (Spain)

    2010-07-15

    Childhood exposure to physical contamination, including non-ionizing radiation, has been implicated in numerous diseases, raising concerns about the widespread and increasing sources of exposure to this type of radiation. The primary objective of this review was to analyze the current state of knowledge on the association between environmental exposure to non-ionizing radiation and the risk of childhood leukemia. Scientific publications between 1979 and 2008 that include examination of this association have been reviewed using the MEDLINE/PubMed database. Studies to date have not convincingly confirmed or ruled out an association between non-ionizing radiation and the risk of childhood leukemia. Discrepancies among the conclusions of the studies may also be influenced by confounding factors, selection bias, and misclassification. Childhood defects can result from genetic or epigenetic damage and from effects on the embryo or fetus, which may both be related to environmental exposure of the parent before conception or during the pregnancy. It is therefore critical for researchers to define a priori the type and 'window' of exposure to be assessed. Methodological problems to be solved include the proper diagnostic classification of individuals and the estimated exposure to non-ionizing radiation, which may act through various mechanisms of action. There appears to be an urgent need to reconsider exposure limits for low frequency and static magnetic fields, based on combined experimental and epidemiological research into the relationship between exposure to non-ionizing radiation and adverse human health effects.

  1. Thyroid carcinoma, cataract and hearing loss in a patient after irradiation for facial hemangioma

    Energy Technology Data Exchange (ETDEWEB)

    Talmi, Y.; Kalmanovitch, M.; Zohar, Y.

    1988-01-01

    A rare case of a patient irradiated on the right side of the face for a large hemangioma during early childhood is reported. This patient suffers from sensorineural hearing loss in the right ear and a cataract of the right eye, and she underwent surgery for Hurtle cell carcinoma of the thyroid gland. The literature discussing radiation-induced hearing loss is reviewed.

  2. Primary versus secondary intraocular lens implantation in the management of congenital cataract

    Directory of Open Access Journals (Sweden)

    Thanaa H Mohamed

    2016-01-01

    Conclusion Primary IOL implantation was found to be safe and effective in the management of congenital cataract; it leads to lower incidence of complications and better visual outcomes compared with aphakia and secondary IOL implantation.

  3. Synchrotron radiation measurement of multiphase fluid saturations in porous media: Experimental technique and error analysis

    Science.gov (United States)

    Tuck, David M.; Bierck, Barnes R.; Jaffé, Peter R.

    1998-06-01

    Multiphase flow in porous media is an important research topic. In situ, nondestructive experimental methods for studying multiphase flow are important for improving our understanding and the theory. Rapid changes in fluid saturation, characteristic of immiscible displacement, are difficult to measure accurately using gamma rays due to practical restrictions on source strength. Our objective is to describe a synchrotron radiation technique for rapid, nondestructive saturation measurements of multiple fluids in porous media, and to present a precision and accuracy analysis of the technique. Synchrotron radiation provides a high intensity, inherently collimated photon beam of tunable energy which can yield accurate measurements of fluid saturation in just one second. Measurements were obtained with precision of ±0.01 or better for tetrachloroethylene (PCE) in a 2.5 cm thick glass-bead porous medium using a counting time of 1 s. The normal distribution was shown to provide acceptable confidence limits for PCE saturation changes. Sources of error include heat load on the monochromator, periodic movement of the source beam, and errors in stepping-motor positioning system. Hypodermic needles pushed into the medium to inject PCE changed porosity in a region approximately ±1 mm of the injection point. Improved mass balance between the known and measured PCE injection volumes was obtained when appropriate corrections were applied to calibration values near the injection point.

  4. Experimental investigation on noise radiation characteristics of pulse detonation engine–driven ejector

    Directory of Open Access Journals (Sweden)

    Xi-qiao Huang

    2015-06-01

    Full Text Available The noise radiation characteristics of multi-cycle pulse detonation engine with and without ejector were investigated under different operating frequencies utilizing gasoline as fuel and air as oxidizer. The straight cylindrical ejector with convergent inlet geometry was coaxially installed at different axial locations relative to the exit of the detonation tube. In all the experiments, the equivalence ratios of gasoline–air mixture and the fill fraction were 1.2 and 1.0, respectively. The experimental results implied that the addition of ejector could drastically change the far-field acoustic performance of pulse detonation engine exit and the peak sound pressure level of noise radiation was a strong function of the ejector axial position. But the peak sound pressure level was not sensitive to the operating frequencies which varied from 10 to 25 Hz. The pulse sound pressure level, however, increased with the increase in operating frequencies. The far-field jet-noise measurements of the pulse detonation engine-ejector system also showed that ejector could decrease the peak sound pressure level of pulse detonation engine. The maximum reduction was approximately 8.5 dB. For the current pulse detonation engine test conditions, an optimum ejector position was found to be a downstream axial placement of x/DPDE  = 0.5.

  5. Cataract Surgery Informed Consent Survey | Omolase | Nigerian ...

    African Journals Online (AJOL)

    To evaluate the importance patients attach to informed consent and the information they are given during counselling for cataract surgery. A total number of sixty one patients who came for cataract surgery during the eye camp in Owo in August, 2006 were randomly selected using simple random sampling and interviewed.

  6. Prevalence of Cataract Blindness in Rural Ethiopia

    African Journals Online (AJOL)

    Bernt Lindtjørn

    Salud Pública 2005;17:387–93. 11. Nano ME, Nano HD, Mugica JM, Silva JC, Montaρa. G, Limburg H. Rapid assessment of visual impairment because of cataract and cataract surgical services in urban Argentina. Ophthalmic Epidemiol. 2006; 13:191-7. 12. Limburg H, Foster A, Gilbert C, G J Johnson1, M. Kyndt , M Myatt.

  7. Survey of Cataract Surgical Techniques in Nigeria

    African Journals Online (AJOL)

    PROF SABE NWOSU

    Survey of Cataract Surgical Techniques in Nigeria. Sebastian N N Nwosu. Guinness Eye Center Onitsha , Nigeria. SUMMARY. Objective: To determine the techniques of cataract surgery as currently being practiced by ophthalmologists in Nigeria. Materials and Methods: A self-administered questionnaire was administered ...

  8. Evaluation of Complications of Extracapsular Cataract Extraction ...

    African Journals Online (AJOL)

    hanumantp

    the cornea and avoidance of posterior capsular rent are some of the challenges of the trainee in mastering ECCE. Stepwise supervised training can help a trainee master these steps while keeping the complications at acceptably low levels. Keywords: Cataract, Cataract extraction, Complications, Developing country, ...

  9. Retrobulbar versus subconjunctival anesthesia for cataract surgery ...

    African Journals Online (AJOL)

    Objectives: To compare the effectiveness, in terms of pain relief and akinesia of retrobulbar and subconjunctival an aesthesia during cataract surgery and also to compare the degree of postoperative ptosis associated with each technique. Materials and Methods: Consecutive adult patients undergoing cataract surgery ...

  10. Retrobulbar versus Subconjunctival Anaesthesia for Cataract Surgery

    African Journals Online (AJOL)

    Aim: To test the efficacy of subconjunctival anaesthesia (SCA) for cataract surgery against the established retrobulbar anaesthesia (RBA). Methods: This was a prospective study of 73 adults (44 males, 29 females) selected for cataract surgery and intraocular lens (IOL) implants under local anaesthesia. Their ages ranged ...

  11. Intracapsular cataract extraction with anterior chamber intraocular ...

    African Journals Online (AJOL)

    Aim: To assess the visual outcome of cataract extraction with ACIOL implantation in a Nigerian hospital. Methods: The visual outcome of 50 eyes of 42 patients aged 40 years and above, out of 212 eyes that underwent intracapsular cataract extraction (ICCE) and anterior chamber intraocular lens (ACIOL) implantation, were ...

  12. Visual Outcome of Cataract Surgery | Ukponmwan | Nigerian ...

    African Journals Online (AJOL)

    Purpose: To assess the visu al ou tcome of cataract su rgery in a tertiary hosp ital in Nigeria. Methods: Three hu nd red and seventy eyes (370) that had cataract su rgery in the op hthalmology d ep artment of University of Benin Teaching Hosp ital (UBTH) from July 2007 to December 2008 were includ ed in the stu d y.

  13. Clinical Characteristics of Cataract Patients with Pseudoexfoliation ...

    African Journals Online (AJOL)

    A total of 402 subjects with cataract were examined for the presence of pseudoexfoliation material, type of cataract, intraocular pressure, glaucoma and other factors. The presence of any exfoliation material on the iris, pupil and lens capsule was examined. Data were computed using SPSS version 16.0. Results: Out of the ...

  14. Extracapsular cataract extraction with intraocular lens implantation ...

    African Journals Online (AJOL)

    Cataract is the leading cause of blindness in leprosy patients. Sight restoration to blind leprosy patients prevents them from injuring their anaesthetic limbs. The visual outcome and complications of extracapsular cataract extraction with intraocular lens implant in 42 leprosy and 91 non-leprosy patients were compared.

  15. Pediatric cataract surgery in Madagascar | Randrianotahina ...

    African Journals Online (AJOL)

    Conclusions: In Madagascar, presentation for congenital and developmental cataract is very late, visual outcome poor and follow‑up inadequate. There is an urgent need for a childhood blindness program to effectively deal with pediatric cataract, an avoidable cause of blindness and visual disability in children on the island ...

  16. Congenital aniridia with cataract: case series

    OpenAIRE

    Wang, Jin Da; Zhang, Jing Shang; Xiong, Ying; Li, Jing; Li, Xiao Xia; Liu, Xue; Zhao, Jing; Tsai, Frank F.; Vishal, Jhanji; You, Qi Sheng; Huang, Yao; Wan, Xiu Hua

    2017-01-01

    Background This study evaluates patients with congenital aniridia and cataract who underwent phacoemulsification, capsular tension ring placement, and foldable intraocular lens implantation. Methods In this prospective case series, 10 patients (17 eyes) underwent cataract surgery via a 3.2?mm clear corneal incision. A continuous circular capsulorhexis with

  17. Radiation-induced heart disease: review of experimental data on dose response and pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Hector, S. (Institut fuer Strahlenbiologie, Neuherberg (Germany))

    1992-02-01

    Clinical and experimental heart irradiation can cause a variety of sequelae. A single dose of {>=} 15 Gy leads to a reversible exudative pericarditis, occurring in dogs, rabbits or rats at around 100 days. Its time-course is very similar in all species investigated, but there are considerable species and strain differences in severity and incidence. After longer, dose-dependent latency times chronic congestive myocardial failure develops. The paper reviews experimental data concerning dose response and pathogenesis. (author).

  18. Guiding the Design of Radiation Imagers with Experimentally Benchmarked Geant4 Simulations for Electron-Tracking Compton Imaging

    Science.gov (United States)

    Coffer, Amy Beth

    Radiation imagers are import tools in the modern world for a wide range of applications. They span the use-cases of fundamental sciences, astrophysics, medical imaging, all the way to national security, nuclear safeguards, and non-proliferation verification. The type of radiation imagers studied in this thesis were gamma-ray imagers that detect emissions from radioactive materials. Gamma-ray imagers goal is to localize and map the distribution of radiation within their specific field-of-view despite the fact of complicating background radiation that can be terrestrial, astronomical, and temporal. Compton imaging systems are one type of gamma-ray imager that can map the radiation around the system without the use of collimation. Lack of collimation enables the imaging system to be able to detect radiation from all-directions, while at the same time, enables increased detection efficiency by not absorbing incident radiation in non-sensing materials. Each Compton-scatter events within an imaging system generated a possible cone-surface in space that the radiation could have originated from. Compton imaging is limited in its reconstructed image signal-to-background due to these source Compton-cones overlapping with background radiation Compton-cones. These overlapping cones limit Compton imaging's detection-sensitivity in image space. Electron-tracking Compton imaging (ETCI) can improve the detection-sensitivity by measuring the Compton-scattered electron's initial trajectory. With an estimate of the scattered electron's trajectory, one can reduce the Compton-back-projected cone to a cone-arc, thus enabling faster radiation source detection and localization. However, the ability to measure the Compton-scattered electron-trajectories adds another layer of complexity to an already complex methodology. For a real-world imaging applications, improvements are needed in electron-track detection efficiency and in electron-track reconstruction. One way of measuring Compton

  19. [The application of low-intensity electromagnetic radiation under immobilization stress conditions (an experimental study)].

    Science.gov (United States)

    Korolev, Iu N; Bobrovnitskiĭ, I P; Nikoulina, L A; Mikhaĭlik, L V; Geniatulina, M S; Bobkova, A S

    2014-01-01

    The experiments carried out on outbred male white rats with the use of optical, electron-microscopic, biochemical, and radioimmunological methods have demonstrated that the application of low-intensity electromagnetic radiation (LI-EMR) with a flow density of 1 mcW/cm2 and a frequency of around 1,000 MHz both in the primary prophylaxis regime and as the therapeuticpreventive modality arrested the development of post-stress disorders in the rat testicles, liver, and thymus; moreover, it promoted activation of the adaptive, preventive, and compensatory processes. The data obtained provide a rationale for the application of low-intensity electromagnetic radiation to protect the organism from negative effects of stressful factors.

  20. Cataract surgery after Descemet stripping endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Sunita Chaurasia

    2012-01-01

    Full Text Available Management of endothelial dysfunction in phakic patients is sometimes a dilemma for corneal surgeons. Phakic patients with visually significant cataract and endothelial dysfunction are preferably managed by performing combined cataract surgery with endothelial keratoplasty. However, combined surgery may be deferred in eyes with early incipient cataract, younger age and where anterior chamber is poorly visualized. As cataract formation may be accelerated after endothelial keratoplasty, these eyes may need cataract surgery subsequently. Surgical intervention in eyes with endothelial keratoplasty is of concern as this may affect the graft adversely and threaten graft survival. In this report, we describe the intraoperative surgical details and postoperative clinical course of a patient who underwent phacoemulsification with intraocular lens implantation after Descemet stripping automated endothelial keratoplasty (DSAEK.

  1. Medical radiation exposure and its impact on occupational practices in Korean radiologic technologists

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seul Ki; Lee, Won Jin [Dept. of Preventive Medicine, Korea University College of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    The use of radiology examinations in medicine has been growing worldwide. Annually an estimated 3.1 billion radiologic exams are performed. According to this expansion of medical radiation exposure, it has been hard to pay no attention to the effects of medical radiation exposures in the exposure from different types of radiation source. This study, therefore, was aimed to assess the association of medical and occupational radiation exposure in Korean radiologic technologists and evaluate necessity for its consideration in occupational studies. This study did not show the strong association between medical radiation exposure and occupational radiation exposure except several modalities with specific frequency. These results are preliminary but certainly meaningful for interpretation of epidemiologic finding, therefore, we need further evaluation specially for the repeatedly exposed imaging tests and high dose procedures that presented somewhat weak relationship in this study linked with health outcomes of radiation exposure. This study did not show the strong association between medical radiation exposure and occupational radiation exposure except several modalities with specific frequency. These results are preliminary but certainly meaningful for interpretation of epidemiologic finding, therefore, we need further evaluation specially for the repeatedly exposed imaging tests and high dose procedures that presented somewhat weak relationship in this study linked with health outcomes of radiation exposure.

  2. Observation of Influence of Cataract Surgery on the Ocular Surface.

    Directory of Open Access Journals (Sweden)

    Yuli Park

    . Therefore, it could elucidate the development of dry eye related to cataract surgery.

  3. Stenotrophomonas maltophilia endophthalmitis following cataract surgery: clinical and microbiological results

    Directory of Open Access Journals (Sweden)

    Chang JS

    2013-04-01

    Full Text Available Jonathan S Chang, Harry W Flynn Jr, Darlene Miller, William E Smiddy Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA Background: Stenotrophomonas maltophilia is a Gram-negative organism known to cause opportunistic infections. It is a rare source of endophthalmitis, often in the setting of trauma, but has been reported following cataract extraction. The purpose of this study was to evaluate antimicrobial sensitivities, clinical characteristics, and treatment outcomes in patients with endophthalmitis caused by S. maltophilia following cataract extraction. Methods: A retrospective case review of records from January 1, 1990 to June 30, 2010 was performed at the Bascom Palmer Eye Institute. Results: Eight cases of S. maltophilia endophthalmitis were identified following cataract surgery. Initial visual acuity ranged from 20/200 to light perception. Time to diagnosis with cultures was 2–118 days. Patients received either intravitreal tap and inject (n = 5 or pars plana vitrectomy with intravitreal antibiotic injections (n = 3. All patients had vitreous or anterior chamber cultures positive for S. maltophilia. Seven of seven isolates tested were found to be sensitive to ceftazidime. Seven of eight isolates were sensitive to polymyxin B, six of eight isolates were sensitive to amikacin, and five of the seven isolates tested were sensitive to ciprofloxacin. Two of four tested isolates were sensitive to trimethoprim-sulbactam. All eight isolates were resistant to gentamicin and seven of the seven tested isolates were resistant to imipenem. All patients received intravitreal ceftazidime as part of the initial treatment regimen. Final visual acuity ranged from 20/25 to 4/200. Conclusion: S. maltophilia endophthalmitis is a rare source of endophthalmitis following cataract surgery. A case series of eight independent patients is reported, along with antibiotic resistance profiles and

  4. A prospective study on postoperative pain after cataract surgery

    Directory of Open Access Journals (Sweden)

    Porela-Tiihonen S

    2013-07-01

    Full Text Available Susanna Porela-Tiihonen,1 Kai Kaarniranta,2 Merja Kokki,1 Sinikka Purhonen,1 Hannu Kokki1 1Department of Anesthesia and Operative Services, Kuopio University Hospital, School of Medicine, University of Eastern Finland, Kuopio, Finland; 2Department of Ophthalmology, Kuopio University Hospital, School of Medicine, University of Eastern Finland, Kuopio, Finland Purpose: To evaluate postoperative pain and early recovery in cataract patients. Patients and methods: A total of 201 patients who underwent elective first eye cataract extraction surgery were enrolled, and 196 were included in the final analysis. The study design was a single-center, prospective, follow-up study in a tertiary hospital in eastern Finland. Postoperative pain was evaluated with the Brief Pain Inventory at four time points: at baseline, and at 24 hours, 1 week, and 6 weeks postsurgery. Results: Postoperative pain was relatively common during the first hours after surgery, as it was reported by 67 (34% patients. After hospital discharge, the prevalence decreased; at 24 hours, 1 week, and 6 weeks, 18 (10%, 15 (9% and 12 (7% patients reported having ocular pain, respectively. Most patients with eye pain reported significant pain, with a score of ≥4 on a pain scale of 0–10, but few had taken analgesics for eye pain. Those who had used analgesics rated the analgesic efficacy of paracetamol and ibuprofen as good or excellent. Other ocular irritation symptoms were common after surgery; as a new postoperative symptom, foreign-body sensation was reported by 40 patients (22%, light sensitivity by 29 (16%, burning by 15 (8%, and itching by 15 (8%. Conclusion: Moderate or severe postoperative pain was relatively common after cataract surgery. Thus, all patients undergoing cataract surgery should be provided appropriate counseling on pain and pain management after surgery. Keywords: eye, cataract extraction, phacoemulsification, refractive surgical procedures, follow-up study, recovery

  5. The Measurement of Radiative Lifetimes Using Laser-Induced Fluorescence: Experimental Review and Astrophysical Application

    Energy Technology Data Exchange (ETDEWEB)

    Hartog, E.A. den; Lawler, J.E. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Sneden, C. [Univ. of Texas, Austin, TX (United States). Dept. of Astronomy and McDonald Observatory

    2005-10-01

    One of the standard methods for determining atomic transition probabilities is to combine branching fractions measured using Fourier-transform spectrometry with radiative lifetimes measurements using laser-induced fluorescence (LIF). This combination of techniques provides an efficient method for measuring large sets of accurate, absolute transition probabilities. The radiative lifetimes, which provide the overall scaling for the transition probabilities, can be measured routinely to {+-}5% accuracy using time-resolved LIF. Although the time-resolved LIF technique we use does not achieve the accuracy of fast-beam LIF, the time-resolved technique does enable us to make measurements at a far greater rate (hundreds of level lifetimes per year). Care must be taken, however, to understand and control the systematic effects in time-resolved LIF measurements to maintain {+-}5% accuracy over a wide dynamic range and hundreds of lifetime measurements. Over the last 25 years, we have measured lifetimes for 47 spectra using time resolved LIF. Our atomic beam source can produce a slow beam of neutral and singly ionized atoms of nearly any element. Lifetimes from 2 ns to {approx}2{mu}s can be measured for energy levels ranging from 15,000 to {approx}60,000/cm. In this review we will describe our method of measuring radiative lifetimes with an emphasis on possible errors and techniques used for controlling them. The electronic bandwidth, linearity, and overall fidelity of the fast photomultiplier, cable connections, and transient waveform digitizer are concerns. Possible errors from atomic collisions, radiation trapping, Zeeman quantum beats, hyperfine quantum beats, atoms/ions escaping from the observation region before radiating, and from radiative cascade through lower levels must be understood and controlled. We will then present a recent example of the application of our transition probability data to abundance determinations in the sun and in metal-poor halo stars. Our

  6. Radiation-Induced Testicular Injury and Its Amelioration by Tinospora cordifolia (An Indian Medicinal Plant Extract

    Directory of Open Access Journals (Sweden)

    Priyanka Sharma

    2011-01-01

    Full Text Available The primary objective of this investigation is to determine the deleterious effects of sub lethal gamma radiation on testes and their possible inhibition by Tinospora cordifolia extract (TCE. For this purpose, one group of male Swiss albino mice was exposed to 7.5 Gy gamma radiation to serve as the irradiated control, while the other group received TCE (75 mg/kg b. wt./day orally for 5 consecutive days half an hr before irradiation to serve as experimental. Exposure of animals to 7.5 Gy gamma radiation resulted into significant decrease in body weight, tissue weight, testes- body weight ratio and tubular diameter up to 15 days of irradiation. Cent percent mortality was recorded by day 17th in irradiated control, whereas all animals survived in experimental group. TCE pretreatment rendered significant increase in body weight, tissue weight, testes- body weight ratio and tubular diameter at various intervals as compared to irradiated group. Radiation induced histological lesions in testicular architecture were observed more severe in irradiated control then the experimental. TCE administration before irradiation significantly ameliorated radiation induced elevation in lipid peroxidation and decline in glutathione concentration in testes. These observations indicate the radio- protective potential of Tinospora cordifolia root extract in testicular constituents against gamma irradiation in mice.

  7. [Contemporary views on the pathogenesis and possible prophylaxis of age related cataracts].

    Science.gov (United States)

    Kałuzny, J J; Kałuzny, J

    1997-01-01

    In this review the role of UVB/290-320 nm/ and visible light radiation in generating of free radicals in the lens is described, which is the main factor leading to development of senile cataract. Also the mechanisms of antioxidant defence are presented especially glutathione and ascorbic acid. We review the literature connected with diet supplementation of antioxidants /vit. E, C, selenium/. According to actual theories the use of sun-glasses with UVB-filters, and antioxidant diet supplementation seems to be useful in prevention of age-related cataract.

  8. Radiation effects in cold moderator materials: Experimental study of accumulation and release of chemical energy

    Science.gov (United States)

    Kulagin, E.; Kulikov, S.; Melikhov, V.; Shabalin, E.

    2004-01-01

    Study of radiation resistance of hydrogenous materials at low temperatures is a first priority task in the design of advanced cold neutron moderators. At temperatures 20-100 K the most essential radiation effects in solid hydrogenous substances are: Formation of radiolytic hydrogen. Accumulation of "frozen" radicals, which results in a rise of a self-sustaining reaction of their recombination followed with unexpected fast heating of the moderator. Formation of high-molecular, high-boiling products of radiolysis. Decrease of thermal conductivity. In the paper, the recently obtained results of the study of the accumulation of chemical energy and the conditions of its release performed with the URAM-2 cryogenic irradiation facility at the IBR-2 research reactor, are presented. Spontaneous releases of stored energy were detected in solid methane, water ice, hydrates of methane and tetrahydrofuran [Particles and Nuclei, Lett. 5 (2002) 82; Radiat. Phys. Chem. 67 (2003) 315] and in frozen mixtures of water ice with atomic hydrogen scavengers. A negligible amount of energy is accumulated in aromatic hydrocarbons which demonstrate no spontaneous self-heating under irradiation. All irradiation runs were performed at up to 20 MGy in the temperature range of 15-50 K.

  9. Hematological Changes Induced by Mercury Ions and Ionizing Radiation in Experimental Animals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Kyu; Lee, Yun-Jong; Choi, Dae-Seong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, Ji-Hyang [Biotechnology Research Institute, Seoul (Korea, Republic of); Cebulska-Wasilewska, Antonina [The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland)

    2006-07-01

    Toxic metals such as lead, chromium, cadmium, mercury and arsenic are widely found in our environment. Humans are exposed to these metals from numerous sources, including contaminated air, water, soil and food. Mercury, one of the most diffused and hazardous organ specific environmental contaminants, exists in a wide variety of physical and chemical states, each of which has unique characteristics for a target organ specificity. Although reports indicate that mercury induces deleterious damage, little is known about its effects on living organisms. Ionizing radiation, an extensively used therapeutic modality in oncology, not only eradicates neoplastic cells but also generates inevitable side effects for normal tissues. Such biological effects are made through the production of reactive oxygen species which include a superoxide anion, a hydroxyl radical and a hydrogen peroxide. These reactive species may contribute to the radiation-induced cytotoxicity (e.g., chromosome aberrations, protein oxidation, and muscle injury) and to the metabolic and morphologic changes (e.g., increased muscle proteolysis and changes in the central nervous system) in animals and humans. In the present study, radioimmunoassay of the cortisol in the serum and the analysis of the hematological components and enzymes related to a tissue injury were carried out to evaluate the effects of mercury chloride in comparison with those of ionizing radiation.

  10. Gigantol from Dendrobium chrysotoxum Lindl. binds and inhibits aldose reductase gene to exert its anti-cataract activity: an in vitro mechanistic study

    Science.gov (United States)

    Ethnopharmacological relevance: Dendrobium. chrysotoxum Lindl is a commonly used species of medicinal Dendrobium which belongs to the family of Orchidaceae, locally known as Shihu or Huangcao. D. chrysotoxum Lindl is widely known for medicinal values in traditional Chinese medicine as it possesses a...

  11. Review: Femtosecond Laser Assisted Cataract Surgery (FLACS): An ...

    African Journals Online (AJOL)

    Age-related cataract is one of the most important causes of visual impairment, and cataract surgery is one of the commonest surgeries performed worldwide. Femtosecond laser assisted cataract surgery (FLACS) is a new and promising technology in the arena of cataract operations. Femtosecond lasers (FSL) are used in ...

  12. Evaluation of the Community Cataract Surgical Services of a ...

    African Journals Online (AJOL)

    Background: Cataract is the leading cause of blindness in the world. An efficient and effective cataract surgical service is necessary to reduce the backlog of cataract blindness in the community. This study aims to determine the cataract surgical coverage among individuals aged 50 years and above residing in Esie and ...

  13. Cataract Surgical Outreach in a Tertiary Hospital in Nigeria: An ...

    African Journals Online (AJOL)

    Background: Cataract remains the main cause of reversible blindness in Nigeria. However, access to cataract surgery has been hampered by lack of funds and a dearth of eye care professionals. Surgical outreaches have been used as one of the tools to reduce the cataract backlog. Aim: To review a free cataract surgical ...

  14. Dose-dependent misrejoining of radiation-induced DNA double-strand breaks in human fibroblasts: Experimental and theoretical study for high and low LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, Bjorn; Cooper, Brian; Cooper, Priscilla K.; Holley, William; Chatterjee, Aloke

    2004-11-18

    Misrejoining of DNA double-strand breaks (DSBs) was measured in human primary fibroblasts after exposure to X-rays and high LET particles (He, N and Fe) in the dose range 10-80 Gy. To measure joining of wrong DNA ends, the integrity of a 3.2 Mbp restriction fragment was analyzed directly after exposure and after 16 hr of repair incubation. It was found that the misrejoining frequency for X-rays was non-linearly related to dose, with less probability of misrejoining at low doses than at high doses. The dose dependence for the high LET particles, on the other hand, was closer to being linear, with misrejoining frequencies higher than for X-rays particularly at the lower doses. These experimental results were simulated with a Monte-Carlo approach that includes a cell nucleus model with all 46 chromosomes present, combined with realistic track structure simulations to calculate the geometrical positions of all DSBs induced for each dose. The model assumes that the main determinant for misrejoining probability is the distance between two simultaneously present DSBs. With a Gaussian interaction probability function with distance, it was found that both the low and high LET data could be fitted with an interaction distance (sigma of the Gaussian curve) of 0.25 {micro}m. This is half the distance previously found to best fit chromosomal aberration data in human lymphocytes using the same methods (Holley et al. Radiat. Res . 158, 568-580 (2002)). The discrepancy may indicate inadequacies in the chromosome model, for example insufficient chromosomal overlap, but may also partly be due to differences between fibroblasts and lymphocytes. Although the experimental data was obtained at high doses, the Monte Carlo calculations could be extended to lower doses. It was found that a linear component of misrejoining versus dose dominated for doses below 1 Gy for all radiations, including X-rays. The calculated relative biological efficiency (RBE) for misrejoining at this low dose

  15. Largest temperature of the radiation era and its cosmological implications

    CERN Document Server

    Giudice, Gian Francesco; Riotto, Antonio; Giudice, Gian Francesco; Kolb, Edward W.; Riotto, Antonio

    2001-01-01

    The thermal history of the universe before the epoch of nucleosynthesis is unknown. The maximum temperature in the radiation-dominated era, which we will refer to as the reheat temperature, may have been as low as 0.7 MeV. In this paper we show that a low reheat temperature has important implications for many topics in cosmology. We show that weakly interacting massive particles (WIMPs) may be produced even if the reheat temperature is much smaller than the freeze-out temperature of the WIMP, and that the dependence of the present abundance on the mass and the annihilation cross section of the WIMP differs drastically from familiar results. We revisit predictions of the relic abundance and resulting model constraints of supersymmetric dark matter, axions, massive neutrinos, and other dark matter candidates, nucleosynthesis constraints on decaying particles, and leptogenesis by decay of superheavy particles. We find that the allowed parameter space of supersymmetric models is altered, removing the usual bounds...

  16. It Pays to Compare: An Experimental Study on Computational Estimation

    Science.gov (United States)

    Star, Jon R.; Rittle-Johnson, Bethany

    2009-01-01

    Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N = 157) learned about…

  17. Quantum adiabatic algorithm for factorization and its experimental implementation.

    Science.gov (United States)

    Peng, Xinhua; Liao, Zeyang; Xu, Nanyang; Qin, Gan; Zhou, Xianyi; Suter, Dieter; Du, Jiangfeng

    2008-11-28

    We propose an adiabatic quantum algorithm capable of factorizing numbers, using fewer qubits than Shor's algorithm. We implement the algorithm in a NMR quantum information processor and experimentally factorize the number 21. In the range that our classical computer could simulate, the quantum adiabatic algorithm works well, providing evidence that the running time of this algorithm scales polynomially with the problem size.

  18. Experimentally Induced Learned Helplessness: How Far Does it Generalize?

    Science.gov (United States)

    Tuffin, Keith; And Others

    1985-01-01

    Assessed whether experimentally induced learned helplessness on a cognitive training task generalized to a situationally dissimilar social interaction test task. No significant differences were observed between groups on the subsequent test task, showing that helplessness failed to generalize. (Author/ABB)

  19. Infrared characteristic radiation of water condensation and freezing in connection with atmospheric phenomena; Part 3: Experimental data

    Science.gov (United States)

    Tatartchenko, V.; Liu, Yifan; Chen, Wenyuan; Smirnov, P.

    2012-09-01

    This paper is the third one from the series of papers with the same titles published in this journal. The papers consider the infrared characteristic radiation (IRCR) during the first order phase transitions of water: crystallization, water vapor condensation, and water vapor deposition. Experimental results are analyzed in terms of their correspondence to the theoretical model. This model is based on the assertion that the particle's (atom, molecule, or cluster) transition from the higher energetic level in a metastable phase (vapor or liquid) to a lower level in a stable phase (liquid or crystal) produces an emission of one or more photons. The energy of these photons depends on the latent energy of the phase transition and the character of bonds formed by the particle in the new phase. For all investigated substances, this energy falls in the infrared range. Recorded in the atmosphere, numerous sources of the infrared radiation seem to be a result of crystallization, condensation and deposition of water during fog and cloud formation. The effect under investigation must play a very important role in atmospheric phenomena: it is one of the sources of Earth's cooling; formation of hailstorm clouds is accompanied by intensive IRCR that could be detected for process characterization and meteorological warnings. IRCR seems to be used for atmospheric energy accumulation and together with the wind, falling water, solar and geothermal energies makes available the fifth source of ecologically pure energy.

  20. Quality of care from the perspective of the cataract patient: the reliability and validity of the QUOTE-Cataract.

    NARCIS (Netherlands)

    Nijkamp, M.D.; Sixma, H.J.M.; Afman, H.; Hiddema, F.; Koopmans, S.A.; Borne, B. van den

    2002-01-01

    Background/aims: To assess reliability and validity of the QUOTE-Cataract, a questionnaire that measures the quality of care from the perspective of cataract patients. Methods: The QUOTE-Cataract was tested in a multicentre study among 540 cataract patients in three different hospitals. Reliability

  1. Quality of care from the perspective of the cataract patient : the reliability and validity of the QUOTE-Cataract

    NARCIS (Netherlands)

    Nijkamp, MD; Sixma, HJM; Afman, H; Hiddema, F; Koopmans, SA; van den Borne, B; Hendrikse, F; Nuijts, RMMA

    Background/aims: To assess reliability and validity of the QUOTE-cataract, a questionnaire that measures the quality of care from the perspective of cataract patients. Methods: The QUOTE-cataract was tested in a multicentre study among 540 cataract patients in three different hospitals. Reliability

  2. The social construction of paediatric cataract: how parents make sense of their child’s condition

    Directory of Open Access Journals (Sweden)

    Pradeep Krishnatray

    2006-09-01

    Full Text Available IntroductionChildhood cataract, congenital and traumatic, is the most common treatable cause of childhood blindness, being responsible for 10 to 30 per cent of all childhood blindness. Preventing blindness from childhood cataract requires not only high-quality paediatric surgery, but also an awareness of parents’ understanding of the eye problem, and why they might not agree to surgery for their child. Several studies have examined the medical and social aspects of childhood cataract. Foster et al.1 point out that childhood blindness has huge socio-economic costs, and restoring the sight of one child blind from cataract is considered equivalent to restoring the sight of 10 elderly adults. It is therefore crucial that we understand why parents might not take up the option of surgery.

  3. Genetic and Dietary Factors Influencing the Progression of Nuclear Cataract

    OpenAIRE

    Yonova-Doing, Ekaterina; Forkin, Zoe A.; Hysi, Pirro G.; Williams, Katie M.; Spector, Tim D.; Clare E Gilbert; Hammond, Christopher J.

    2016-01-01

    PURPOSE: To determine the heritability of nuclear cataract progression and to explore prospectively the effect of dietary micronutrients on the progression of nuclear cataract.DESIGN: Prospective cohort study.PARTICIPANTS: Cross-sectional nuclear cataract and dietary measurements were available for 2054 white female twins from the TwinsUK cohort. Follow-up cataract measurements were available for 324 of the twins (151 monozygotic and 173 dizygotic twins).METHODS: Nuclear cataract was measured...

  4. New mutation in the mouse Xpd/Ercc2 gene leads to recessive cataracts.

    Directory of Open Access Journals (Sweden)

    Sarah Kunze

    Full Text Available Cataracts are the major eye disorder and have been associated mainly with mutations in lens-specific genes, but cataracts are also frequently associated with complex syndromes. In a large-scale high-throughput ENU mutagenesis screen we analyzed the offspring of paternally treated C3HeB/FeJ mice for obvious dysmorphologies. We identified a mutant suffering from rough coat and small eyes only in homozygotes; homozygous females turned out to be sterile. The mutation was mapped to chromosome 7 between the markers 116J6.1 and D7Mit294;4 other markers within this interval did not show any recombination among 160 F2-mutants. The critical interval (8.6 Mb contains 3 candidate genes (Apoe, Six5, Opa3; none of them showed a mutation. Using exome sequencing, we identified a c.2209T>C mutation in the Xpd/Ercc2 gene leading to a Ser737Pro exchange. During embryonic development, the mutant eyes did not show major changes. Postnatal histological analyses demonstrated small cortical vacuoles; later, cortical cataracts developed. Since XPD/ERCC2 is involved in DNA repair, we checked also for the presence of the repair-associated histone γH2AX in the lens. During the time, when primary lens fiber cell nuclei are degraded, γH2AX was strongly expressed in the cell nuclei; later, it demarcates clearly the border of the lens cortex to the organelle-free zone. Moreover, we analyzed also whether seemingly healthy heterozygotes might be less efficient in repair of DNA damage induced by ionizing radiation than wild types. Peripheral lymphocytes irradiated by 1Gy Cs137 showed 6 hrs after irradiation significantly more γH2AX foci in heterozygotes than in wild types. These findings demonstrate the importance of XPD/ERCC2 not only for lens fiber cell differentiation, but also for the sensitivity to ionizing radiation. Based upon these data, we hypothesize that variations in the human XPD/ERCC2 gene might increase the susceptibility for several disorders besides Xeroderma

  5. Fast Bayesian optimal experimental design and its applications

    KAUST Repository

    Long, Quan

    2015-01-07

    We summarize our Laplace method and multilevel method of accelerating the computation of the expected information gain in a Bayesian Optimal Experimental Design (OED). Laplace method is a widely-used method to approximate an integration in statistics. We analyze this method in the context of optimal Bayesian experimental design and extend this method from the classical scenario, where a single dominant mode of the parameters can be completely-determined by the experiment, to the scenarios where a non-informative parametric manifold exists. We show that by carrying out this approximation the estimation of the expected Kullback-Leibler divergence can be significantly accelerated. While Laplace method requires a concentration of measure, multi-level Monte Carlo method can be used to tackle the problem when there is a lack of measure concentration. We show some initial results on this approach. The developed methodologies have been applied to various sensor deployment problems, e.g., impedance tomography and seismic source inversion.

  6. Microscope Integrated Intraoperative Spectral Domain Optical Coherence Tomography for Cataract Surgery: Uses and Applications.

    Science.gov (United States)

    Das, Sudeep; Kummelil, Mathew Kurian; Kharbanda, Varun; Arora, Vishal; Nagappa, Somshekar; Shetty, Rohit; Shetty, Bhujang K

    2016-05-01

    To demonstrate the uses and applications of a microscope integrated intraoperative Optical Coherence Tomography in Micro Incision Cataract Surgery (MICS) and Femtosecond Laser Assisted Cataract Surgery (FLACS). Intraoperative real time imaging using the RESCAN™ 700 (Carl Zeiss Meditec, Oberkochen, Germany) was done for patients undergoing MICS as well as FLACS. The OCT videos were reviewed at each step of the procedure and the findings were noted and analyzed. Microscope Integrated Intraoperative Optical Coherence Tomography was found to be beneficial during all the critical steps of cataract surgery. We were able to qualitatively assess wound morphology in clear corneal incisions, in terms of subclinical Descemet's detachments, tears in the inner or outer wound lips, wound gaping at the end of surgery and in identifying the adequacy of stromal hydration, for both FLACS as well as MICS. It also enabled us to segregate true posterior polar cataracts from suspected cases intraoperatively. Deciding the adequate depth of trenching was made simpler with direct visualization. The final position of the intraocular lens in the capsular bag and the lack of bioadhesivity of hydrophobic acrylic lenses were also observed. Even though Microscope Integrated Intraoperative Optical Coherence Tomography is in its early stages for its application in cataract surgery, this initial assessment does show a very promising role for this technology in the future for cataract surgery both in intraoperative decision making as well as for training purposes.

  7. The transition radiation. 2. experimental study of the optical transition radiation; Le rayonnement de transition: 2. etude experimentale du rayonnement de transition optique

    Energy Technology Data Exchange (ETDEWEB)

    Couillaud, Ch.; Haouat, G.; Seguin, S.; Striby, S

    1999-07-01

    Optical-transition-radiation-based diagnostics have been widely used for many years on electron accelerators in order to measure beam energy and transverse and longitudinal emittances. These diagnostics are very attractive for high brightness electron beams used as drivers for radiation sources. Such diagnostics have been performed on the ELSA facility (18 MeV electron energy, 100 A peak current) using both a single interface and an OTR-Wartski interferometer. We present the accelerator, the experimental set-up and the method for analyzing the OTR angular distribution. Then, the experimental results are described and compared with those from the three gradient method. In addition, we present a beam energy measurement using OTR interferogram analysis. (author)

  8. Radiation Shielding Materials Containing Hydrogen, Boron, and Nitrogen: Systematic Computational and Experimental Study Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objectives of the proposed research are to develop a space radiation shielding material system that has high efficacy for shielding radiation and also has high...

  9. Working with patients to optimise cataract outcomes

    Directory of Open Access Journals (Sweden)

    Nick Astbury

    2016-10-01

    Full Text Available One of the delights of ophthalmology is to witness the joy on the face of a patient with cataract when the dressing is taken off and sight has been restored. Unfortunately, for some patients, the result does not live up to their expectations. Despite cataract surgery being one of the most successful surgical interventions available, there is evidence that the visual outcome of cataract surgery in sub-Saharan Africa is not always good (defined as a VA of 6/18 or better. The proportion of good outcomes range from only 23% up to 70%, failing to reach the WHO target of 85% or better.

  10. Congenital aniridia with cataract: case series.

    Science.gov (United States)

    Wang, Jin Da; Zhang, Jing Shang; Xiong, Ying; Li, Jing; Li, Xiao Xia; Liu, Xue; Zhao, Jing; Tsai, Frank F; Vishal, Jhanji; You, Qi Sheng; Huang, Yao; Wan, Xiu Hua

    2017-07-04

    This study evaluates patients with congenital aniridia and cataract who underwent phacoemulsification, capsular tension ring placement, and foldable intraocular lens implantation. In this prospective case series, 10 patients (17 eyes) underwent cataract surgery via a 3.2 mm clear corneal incision. A continuous circular capsulorhexis with cataract by phacoemulsification, posterior chamber foldable lens implantation, capsular tension ring placement was safe and effective. Use of colored contact lenses in the postoperative period can reduce photophobic symptoms in this group of patients. ChiCTR-OOC-17011638 (retrospectively registered at 12,June,2017).

  11. Sutureless Cataract Surgery: Principles and Steps

    Directory of Open Access Journals (Sweden)

    John Sandford-Smith

    2003-01-01

    Full Text Available Introduction. Cataracts cause about 50% of world blindness. There is little likelihood of effective prevention becoming available in the next few years and so the only treatment will remain surgical. For many of the other major causes of world blindness, like trachoma, xerophthalmia and onchocerciasis, the remedy is community-based, not hospital-based, and requires prevention rather than treatment. The prevalence of blinding cataract will only increase as people live longer, so cataract will continue to be, by far, the most important treatable cause of blindness.

  12. Brain Radiation Information Data Exchange (BRIDE): Integration of experimental data from low-dose ionising radiation research for pathway discovery

    NARCIS (Netherlands)

    C. Karapiperis (Christos); S.J. Kempf (Stefan J.); R. Quintens (Roel); O. Azimzadeh (Omid); V.L. Vidal (Victoria Linares); S. Pazzaglia; D. Bazyka (Dimitry); P.G. Mastroberardino (Pier); Z.G. Scouras (Zacharias G.); S. Tapio (Soile); M.A. Benotmane (Mohammed Abderrafi); C.A. Ouzounis (Christos A.)

    2016-01-01

    textabstractBackground: The underlying molecular processes representing stress responses to low-dose ionising radiation (LDIR) in mammals are just beginning to be understood. In particular, LDIR effects on the brain and their possible association with neurodegenerative disease are currently being

  13. Experimental comparison of laser energy losses in high-quality laser-oxygen cutting of low-carbon steel using radiation from fibre and CO2 lasers

    Science.gov (United States)

    Golyshev, A. A.; Malikov, A. G.; Orishich, A. M.; Shulyat'ev, V. B.

    2015-09-01

    We report a comparative experimental study of laseroxygen cutting of low-carbon steel using a fibre laser with a wavelength of 1.07 μm and a CO2 laser with a wavelength of 10.6 μm at the sheet thickness of 3 - 16 mm. For the two lasers we have measured the dependence of the cutting speed on the radiation power and determined the cutting speed at which the surface roughness is minimal. The coefficient of laser radiation absorption in the laser cutting process is measured for these lasers at different values of the cutting speed and radiation power. It is found that the minimal roughness of the cut surface is reached at the absorbed laser energy per unit volume of the removed material, equal to 11 - 13 J mm-3; this value is the same for the two lasers and does not depend on the sheet thickness.

  14. Simulation of the spatial distribution of mineral dust and its direct radiative forcing over Australia

    Directory of Open Access Journals (Sweden)

    Omid Alizadeh Choobari

    2013-05-01

    Full Text Available Direct radiative forcing by mineral dust is important as it significantly affects the climate system by scattering and absorbing short-wave and long-wave radiation. The multi-angle imaging spectro radiometer (MISR and cloud–aerosol lidar with orthogonal polarisation (CALIOP aerosol data are used to observe mineral dust distribution over Australia. In addition, the weather research and forecasting with chemistry (WRF/Chem model is used to estimate direct radiative forcing by dust. At the surface, the model domain clear-sky short-wave and long-wave direct radiative forcing by dust averaged for a 6-month period (austral spring and summer was estimated to be −0.67 W m−2 and 0.13 W m−2, respectively. The long-wave warming effect of dust therefore offsets 19.4% of its short-wave cooling effect. However, over Lake Eyre Basin where coarse particles are more abundant, the long-wave warming effect of dust offsets 60.9% of the short-wave cooling effect. At the top of the atmosphere (TOA, clear-sky short-wave and long-wave direct radiative forcing was estimated to be −0.26 W m−2 and −0.01 W m−2, respectively. This leads to a net negative direct radiative forcing of dust at the TOA, indicating cooling of the atmosphere by an increase in outgoing radiation. Short-wave and long-wave direct radiative forcing by dust is shown to have a diurnal variation due to changes in solar zenith angle and in the intensity of infrared radiation. Atmospheric heating due to absorption of short-wave radiation was simulated, while the interaction of dust with long-wave radiation was associated with atmospheric cooling. The net effect was cooling of the atmosphere near the surface (below 0.2 km, with warming of the atmosphere at higher altitudes.

  15. Experimental study of TJ-1 plasma using scattering and radiation emission techniques; Analisis experimental del plasma TJ-1 con tecnicas de scattering y emision de radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, C.; Zurro, B.

    1987-07-01

    The Thomson scattering system of TJ-1 is described in detail. The radial profiles of Te and ne obtained in TJ-1 discharges are presented. This data make possible to deduce characteristic parameters of the plasma confinement in this machine, as energy confinement times, Zeff B. Using also radiation measurements (global and in the visible range) we obtained the particle confinement time and Zeff without non experimental assumptions. (Author) 52 refs.

  16. Experimental dosimetric evaluation in pelvis phantom, subjected to prostate radiation therapy protocol at 15 MV Linac

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Andrea Silva Dias de; Campos, Tarcisio P.R., E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Humberto Galvao [Centro de Radioterapia Hospital Luxemburgo, Belo Horizonte, MG (Brazil)

    2011-07-01

    Among the existing malignant neoplasia, the prostate cancer is most common among male population. Due to its high incidence and morbidity, there is a need for investment in advanced technology for better treatment associated with research and social mobilization to prevent the disease. As an efficient method of treatment for such tumor, radiation teletherapy brings favorable results for the patient, particularly when the cancer is diagnosed early. There are, however, the needs to assess the absorbed doses that reach the prostate in the radiation protocols in order to certify the treatment efficacy. The present research goal is to obtain the profile of absorbed dose distributed in a synthetic prostate on male pelvis phantom following a standard radiation therapy protocol. The methodology makes use of a NRI made phantom and a 15MV Linac accelerator. This phantom has anthropomorphic and anthropometric features containing the major internal organs, including bone, prostate, intestine, and bladder. The exposition was made in a 15 MV linear accelerator taken the isocenter in four fields as a 'BOX' of opposing beams. The dosimetry was prepared using GafChromic EBT type 2 radiochromic film and calibration in a solid water phantom. The radiochromic films were digitized on the Microtek Scan Maker 6900XL model scanner operating in the transmission mode and optical density readings based on RGB mode in the computer program Imagedig. The absorbance readings were performed in the spectrophotometer SP-220 mark BIOSPECTRO obtaining calibration curves generated by the collected data. The results reproduce the dose distribution generated in two orthogonal radiochromic films positioned onto the synthetic prostate. Discussions regarding the characteristics of the phantom and methods of irradiation in relation to the achieved dose profile will be addressed. (author)

  17. The solar ultraviolet B radiation protection provided by shading devices with regard to its diffuse component.

    Science.gov (United States)

    Kudish, Avraham I; Harari, Marco; Evseev, Efim G

    2011-10-01

    The composition of the incident solar global ultraviolet B (UVB) radiation with regard to its beam and diffuse radiation fractions is highly relevant with regard to outdoor sun protection. This is especially true with respect to sun protection during leisure-time outdoor sun exposure at the shore and pools, where people tend to escape the sun under shade trees or different types of shading devices, e.g., umbrellas, overhangs, etc., believing they offer protection from the erythemal solar radiation. The degree of sun protection offered by such devices is directly related to the composition of the solar global UVB radiation, i.e., its beam and diffuse fractions. The composition of the incident solar global UVB radiation can be determined by measuring the global UVB (using Solar Light Co. Inc., Model 501A UV-Biometer) and either of its components. The beam component of the UVB radiation was determined by measuring the normal incidence beam radiation using a prototype, tracking instrument consisting of a Solar Light Co. Inc. Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The horizontal beam component of the global UVB radiation was calculated from the measured normal incidence using a simple geometric correlation and the diffuse component is determined as the difference between global and horizontal beam radiations. Horizontal and vertical surfaces positioned under a horizontal overhang/sunshade or an umbrella are not fully protected from exposure to solar global UVB radiation. They can receive a significant fraction of the UVB radiation, depending on their location beneath the shading device, the umbrella radius and the albedo (reflectance) of the surrounding ground surface in the case of a vertical surface. Shading devices such as an umbrella or horizontal overhang/shade provide relief from the solar global radiation and do block the solar global UVB radiation to some extent; nevertheless, a significant fraction of the solar global UVB

  18. Tesla Coil Theoretical Model and its Experimental Verification

    Directory of Open Access Journals (Sweden)

    Voitkans Janis

    2014-12-01

    Full Text Available In this paper a theoretical model of Tesla coil operation is proposed. Tesla coil is described as a long line with distributed parameters in a single-wire form, where the line voltage is measured across electrically neutral space. By applying the principle of equivalence of single-wire and two-wire schemes an equivalent two-wire scheme can be found for a single-wire scheme and the already known long line theory can be applied to the Tesla coil. A new method of multiple reflections is developed to characterize a signal in a long line. Formulas for calculation of voltage in Tesla coil by coordinate and calculation of resonance frequencies are proposed. The theoretical calculations are verified experimentally. Resonance frequencies of Tesla coil are measured and voltage standing wave characteristics are obtained for different output capacities in the single-wire mode. Wave resistance and phase coefficient of Tesla coil is obtained. Experimental measurements show good compliance with the proposed theory. The formulas obtained in this paper are also usable for a regular two-wire long line with distributed parameters.

  19. Experimental research on the electromagnetic radiation (EMR) characteristics of cracked rock.

    Science.gov (United States)

    Song, Xiaoyan; Li, Xuelong; Li, Zhonghui; Cheng, Fuqi; Zhang, Zhibo; Niu, Yue

    2018-03-01

    Coal rock would emit the electromagnetic radiation (EMR) while deformation and fracture, and there exists structural body in the coal rock because of mining and geological structure. In this paper, we conducted an experimental test the EMR characteristics of cracked rock under loading. Results show that crack appears firstly in the prefabricated crack tip then grows stably parallel to the maximum principal stress, and the coal rock buckling failure is caused by the wing crack tension. Besides, the compressive strength significantly decreases because of the precrack, and the compressive strength increases with the crack angle. Intact rock EMR increases with the loading, and the cracked rock EMR shows stage and fluctuant characteristics. The bigger the angle, the more obvious the stage and fluctuant characteristics, that is EMR becomes richer. While the cracked angle is little, EMR is mainly caused by the electric charge rapid separates because of friction sliding. While the cracked angle is big, there is another significant contribution to EMR, which is caused by the electric dipole transient of crack expansion. Through this, we can know more clear about the crack extends route and the corresponding influence on the EMR characteristic and mechanism, which has important theoretical and practical significance to monitor the coal rock dynamical disasters.

  20. Ancestry, Socioeconomic Status, and Age-Related Cataract in Asians: The Singapore Epidemiology of Eye Diseases Study.

    Science.gov (United States)

    Chua, Jacqueline; Koh, Jia Yu; Tan, Ava Grace; Zhao, Wanting; Lamoureux, Ecosse; Mitchell, Paul; Wang, Jie Jin; Wong, Tien Yin; Cheng, Ching-Yu

    2015-11-01

    To determine the prevalence of age-related cataract and its ancestral and socioeconomic risk factors in a multi-ethnic Asian population. Population-based, cross-sectional study. A total of 10 033 adults (3353 Chinese, 3280 Malays, and 3400 Indians) aged >40 years in the Singapore Epidemiology of Eye Diseases Study. Study participants were invited for a structured interview and received a standardized comprehensive eye examination. Digital lens photographs were taken from eyes of each participant and graded for nuclear, cortical, and posterior subcapsular (PSC) cataract, following the Wisconsin Cataract Grading System. Prevalence data were compared with the Blue Mountains Eye Study (BMES) in Australia. Information on medical and lifestyle factors was collected using questionnaires and blood samples. To increase the precision of racial definition, genetic ancestry was derived from genome-wide single nucleotide polymorphism markers using principal component analysis. Regression models were used to investigate the association of cataract with socioeconomic factors (education and income) and genetic ancestry. Age-related cataract. A total of 8750 participants (94.0%) had gradable lens photographs. The age-standardized prevalence of cataract surgery in Chinese (16.0%), Malays (10.6%), and Indians (20.2%) was higher than in white subjects (4.1%). We found the age-standardized cataract prevalence in Chinese (30.4%), Malays (37.8%), and Indians (33.1%) was higher than in whites (18.5%). Cataract was 1.5 to 2 times more common in Asians and began 10 years earlier than in white subjects. Malays had significantly higher age-standardized prevalence of nuclear, cortical, and PSC cataract than Chinese (Peducation and lower income were associated with cataract for Chinese and Indians but not Malays. The presence of visual impairment associated with cataract was higher in people aged ≥60 years and Malays. We showed that people of different Asian ethnicities had a higher

  1. Alterations in lens protein tyrosine phosphorylation and phosphatidylinositol 3-kinase signaling during selenite cataract formation.

    Science.gov (United States)

    Chandrasekher, Gudiseva; Sailaja, Dasetty

    2004-02-01

    Protein tyrosine phosphorylation is an important event in the cell signal transduction process. Phosphatidylinositol-3 kinase (PI-3K) is an intracellular signal mediator and plays a key role in many cellular functions. In this study we have examined the changes in lens protein tyrosine phosphorylation and its impact on phosphatidylinositol 3-kinase (PI-3K) signaling during selenite cataract development. Cataract was induced in 10 days old rat pups by a single sub-cutaneous injection of sodium selenite (30 microM/Kg body weight) and lenses were collected at different stages of cataract development. Immunoprecipitation and Western immunoblotting were employed to determine protein tyrosine phosphorylation, PI-3K activity and protein in lens cell extracts. Tyrosine kinase activity in lens membrane preparations was assayed in the presence of a synthetic substrate peptide and [32P]ATP. Protein tyrosine phosphorylation in the lens was disrupted before the onset of cataract. A decrease in tyrosine phosphorylation of lens proteins was observed within 2-3 days of selenite injection (pre-cataract stage). The effect was much more prominent with the progression of cataract. The decrease in protein tyrosine phosphorylation correlated with the decrease in tyrosine kinase activity associated with the lens membrane fraction. Stimulation of normal rat lenses in organ culture with insulin and IGF-1 caused an increase in the phosphorylation of proteins, whose tyrosine phosphorylation status appeared to be diminished during cataract development. Insulin and IGF-1 also stimulated rat lens PI-3K activity. While there was no change in total PI-3K activity during the onset of cataract, the activity of PI-3K associated with tyrosine phosphorylated proteins decreased markedly in pre-cataract lenses. Further, the ability of IGF-1 to stimulate PI-3K activity was significantly reduced in lens epithelial cells treated with selenium. These studies show that signaling events involving the protein

  2. Experimental validation of an ultra-thin metasurface cloak for hiding a metallic obstacle from an antenna radiation at low frequencies

    Science.gov (United States)

    Teperik, Tatiana V.; Burokur, Shah Nawaz; de Lustrac, André; Sabanowski, Guy; Piau, Gérard-Pascal

    2017-07-01

    We demonstrate numerically and experimentally an ultra-thin (≈ λ/240) metasurface-based invisibility cloak for low frequency antenna applications. We consider a monopole antenna mounted on a ground plane and a cylindrical metallic obstacle of diameter smaller than the wavelength located in its near-field. To restore the intrinsic radiation patterns of the antenna perturbed by this obstacle, a metasurface cloak consisting simply of a metallic patch printed on a dielectric substrate is wrapped around the obstacle. Using a finite element method based commercial electromagnetic solver, we show that the radiation patterns of the monopole antenna can be restored completely owing to electromagnetic modes of the resonant cavity formed between the patch and obstacle. The metasurface cloak is fabricated, and the concept is experimentally demonstrated at 125 MHz. Performed measurements are in good agreement with numerical simulations, verifying the efficiency of the proposed cloak.

  3. 3-D Cataract Imaging System

    Science.gov (United States)

    Otten, L. J.; Soliz, P.; McMakin, I.; Greenaway, A.; Blanchard, P.; Ogawa, G.

    This paper describes a new adaptive optics instrument and associated diagnostic system for volumetric, in vivo imaging of the human lens and visual acuity characterization. The system is designed to allow one to capture simultaneous, in-focus images of the human lens at multiple "image planes." Based on the adaptation of a deformable grating originally developed for atmospheric turbulence measurements, the instrument will demonstrate an improvement over current techniques for imaging cortical, nuclear and posterior subcapsular cataracts. The system will characterize the human lens optically and will automatically produce an estimate of visual function as affected by the measured abnormalities in the lens. The process that Kestrel and DERA Malvern will use to demonstrate the key techniques for simultaneously acquiring in vivo lens imagery at multiple focus planes employs a surrogate lens. Eventually the camera could be considered as a replacement for most standard slit lamp instruments allowing them to be converted into a 3-D imaging system.

  4. Corneal astigmatism following cataract extraction.

    Science.gov (United States)

    Wishart, M S; Wishart, P K; Gregor, Z J

    1986-01-01

    The changes in corneal curvature in the first six months after cataract extraction were studied by performing sequential keratometry on a group of 57 patients. 8/0 Virgin silk interrupted sutures were used for the closure of corneoscleral incisions, and 10/0 monofilament tied in double running (bootlace) or single running (continuous) fashion was used for corneal wound closure. A high degree of with-the-rule astigmatism was evident in all patients two weeks postoperatively, but thereafter the character of the astigmatism produced by 8/0 virgin silk and 10/0 monofilament closure was quite different: in the 8/0 virgin silk group there was an early and pronounced shift in the axis of astigmatism to against-the-rule, whereas in the 10/0 monofilament group there was little further change in the astigmatism unless the sutures were removed. Wound compression and wound gape as factors responsible for these changes are discussed. PMID:3539177

  5. Cataract surgical skill assessment tools.

    Science.gov (United States)

    Puri, Sidharth; Sikder, Shameema

    2014-04-01

    After publication of the Accreditation Council for Graduate Medical Education's required competencies for residency training programs, ophthalmology training programs began developing objective assessments to measure resident surgical skill. The application of these evaluation tools represents a move toward standardization in the resident educational process. This review of the assessment tools found that the evaluation rubrics for cataract surgery vary in their level of reliability and validity. Currently, variations in reliability and validity are the only measure of true differences in the evaluation rubrics. Future studies will determine which of the assessment tools is the most practical and efficient for resident training. Neither author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Phacoemulsification in eyes with cataract and pseudoexfoliation syndrome

    Directory of Open Access Journals (Sweden)

    Servet Cetinkaya

    2016-06-01

    Full Text Available AIM: To evaluate the visual outcomes and intraoperative and postoperative complications of phacoemulsification surgery in patients with cataract and pseudoexfoliation syndrome(PEXand the usage of proper surgical techniques and appropriate devices intraoperatively.METHODS: Sixty-seven eyes of 53 patients with PEX and cataract who had undergone phacoemulsification and intraocular lens(IOLimplantation surgery were evaluated retrospectively. The mean age was 71.68±9.96(53-89y, and there were 24(45%males and 29(55%females. Nuclear, cortical, posterior subcapsular, and mature cataracts were all represented.RESULTS: Nuclear cataract was significantly more common than other types(P=0.00. The mean preoperative best corrected visual acuity(BCVAwas 0.99±0.30(SD(0.40-1.50logMAR, and the mean postoperative BCVA was 0.32±0.31(SD(0.00-1.00logMAR(P=0.00. Iris retractors were used in 12(18%eyes. Capsular tension ring(CTRimplantation was used in 15(22%eyes, it was planned in 8(12%and unplanned in 7(10%. Posterior capsule rupture occurred in 4(6%eyes, and vitreous loss occurred in 2(3%eyes. Anterior vitrectomy was performed in these 2 eyes. Conversion to extracapsular cataract extraction(ECCEwas needed in these 2(3%eyes due to large posterior capsular rupture. Persistent corneal edema was observed in 4(6%eyes, and anterior chamber reaction in 5(7%eyes. IOL dislocation occurred in 4(6%eyes, but repositioning was only needed in 1(1.5%eye. Posterior capsule opacification(PCOrequiring Nd:YAG laser capsulotomy developed in 13(20%eyes.CONCLUSION: Postoperative visual acuities of patients with cataract and PEX are satisfactory. However, intraoperative and postoperative complications like posterior capsule rupture, vitreous loss, conversion to ECCE, persistent corneal edema, anterior chamber reaction and IOL dislocation may be observed. To avoid these complications, proper surgical techniques and the use of appropriate devices intraoperatively are essential.

  7. Experimental study of intense radiation in terahertz region based on cylindrical surface wave resonator

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Shaoyan; Ogura, Kazuo; Yambe, Kiyoyuki; Nomizu, Shintaro; Shirai, Akihiro; Yamazaki, Kosuke; Kawamura, Jun; Miura, Takuro; Takanashi, Sho; San, Min Thu [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)

    2015-09-28

    Periodical corrugations structured on a cylindrical conductor have cylindrical surface waves (CSWs), which are reflected at the corrugation ends and form a CSW-resonator. In this paper, intense radiations in terahertz region based on the CSW-resonator are reported. The CSW-resonators with upper cut off frequencies in the modern IEEE G-band (110–300 GHz) are excited by a coaxially injected annular beam in a weakly relativistic region less than 100 kV. It is shown that there exists an oscillation starting energy for the CSW-resonator. Above the starting energy, very intense terahertz radiations on the order of kW are obtained. The operation frequencies in the range of 166–173 GHz and 182–200 GHz are obtained using two types of CSW-resonator with the different corrugation amplitude. Electromagnetic properties of the CSW-resonator can be controlled by the artificial structure and may play an important role in high-intensity terahertz generations and applications.

  8. Negative permeability in magnetostatics and its experimental demonstration

    Science.gov (United States)

    Mach-Batlle, Rosa; Parra, Albert; Prat-Camps, Jordi; Laut, Sergi; Navau, Carles; Sanchez, Alvaro

    2017-09-01

    The control of magnetic fields, essential for our science and technology, is currently achieved by magnetic materials with positive permeability, including ferromagnetic, paramagnetic, and diamagnetic types. Here we introduce materials with negative static permeability as a new paradigm for manipulating magnetic fields. As a first step, we extend the solutions of Maxwell magnetostatic equations to include negative-permeability values. The understanding of these new solutions allow us to devise a negative-permeability material as a suitably tailored set of currents arranged in space, overcoming the fact that passive materials with negative permeability do no exist in magnetostatics. We confirm the theory by experimentally creating a spherical shell that emulates a negative-permeability material in a uniform magnetic field. Our results open new possibilities for creating and manipulating magnetic fields, which can be useful for practical applications.

  9. WHEN TO POSTPONE CATARACT SURGERY: TAKING IN CONSIDERATION PATIENTS' QUALITY OF LIFE

    Directory of Open Access Journals (Sweden)

    Jovanović Miloš

    2015-12-01

    Full Text Available Purpose: Assessment of complication in surgery of complicated cataracts and option of postponement of surgery. Setting: Clinic for eye diseases, Clinical Centre of Serbia Methods: This was a retrospective observational case series. Results: In 16 patients subjected to cataract surgery by method of phacoemulsification, three experienced complications during surgery. Two experienced rupture of posterior lens capsule and prolapse of the vitreous body, and one, expulsive hemorrhage. The visual acuity in all three patients was lesser than the preoperative visual acuity. In the second group of 16 patients, after having been acquainted with the survey, the cataract surgery was postponed and the patients were controlled after one year. The cataract progressed just partially in certain patients and all the patients were satisfied with the status of their vision and did not demand surgery. Conclusions: Cataract surgery in complicated cases may be accompanied by complications with uncertain postoperative visual results. Therefore, in patients with complicated cataracts and relatively preserved visual acuity, it is necessary to be careful with proposing surgery and often obey their wish to postpone surgery. This should be done particularly with patients of advanced age, patients with poor general status of life and in monoculuses

  10. Study on development of education model and its evaluation system for radiation safety

    CERN Document Server

    Seo, K W; Nam, Y M

    2002-01-01

    As one of the detailed action strategy of multi object preparedness for strengthening of radiation safety management by MOST, this project was performed, in order to promote the safety culture for user and radiation worker through effective education program. For the prevention of radiological accident and effective implementation of radiation safety education and training, this project has been carried out the development of education model and its evaluation system on radiation safety. In the development of new education model, education course was classified; new and old radiation worker, temporary worker, lecturer and manager. The education model includes the contents of expanding the education opportunity and workplace training. In the development of evaluation system, the recognition criteria for commission-education institute and inside-education institute which should establish by law were suggested for evaluation program. The recognition criteria contains classification, student, method, facilities, ...

  11. Recessive Dystrophic Epidermolysis Bullosa with Congenital Cataract

    Directory of Open Access Journals (Sweden)

    S M Sharmughan Pillai

    1988-01-01

    Full Text Available Case _ having recessive dystrophic epidermolysis bullosa with severe blistering,scarring, inilia, mucosal ulcerations, corneal involvement, teeth anomalies and deformities of hands and feet had the unusual feature of congenital cortical cataract.

  12. Genetics Home Reference: hypomyelination and congenital cataract

    Science.gov (United States)

    ... fibers and promotes the rapid transmission of nerve impulses. Hypomyelination and congenital cataract is caused by a reduced ability to form myelin (hypomyelination). Additionally, people with this disorder are typically born with a clouding of the ...

  13. Histologic changes in selenite cortical cataract.

    Science.gov (United States)

    Anderson, R S; Trune, D R; Shearer, T R

    1988-09-01

    Massive cortical cataract was produced 15-30 days after a single injection of an overdose of sodium selenite into 14-day-old rats. Most of the cortical cataract appeared to be due to extensive liquefaction of cortical fibers. Water influx, following initial damage to the epithelium by selenium, and action of lens proteases were probable mechanisms for the extensive liquefaction. Remarkably, selenite cortical cataract spontaneously cleared after several months, restoring essentially normal cells to the epithelium and outer and mid-cortex. Major mechanisms for clearing probably involved: (1) removal of damaged proteins from the lens by extensive proteolysis; and (2) replacement of fibers by resumption of normal fibergenesis. The data emphasized the remarkable reparative potential of the lens, and indicated the usefulness of the selenite cortical cataract as a model to study such processes.

  14. [Ocular toxoplasmosis and consecutive complicated cataract].

    Science.gov (United States)

    Corbu, Cătălina; Creţu, Carmen; Predoi, Daniela; Tatu, Mihaela

    2002-01-01

    The paper reports three clinical cases which have in common two elements: ocular toxoplasmosis and consecutive complicative cataract, the method of treatment, the evolution and the recovery visual acuity.

  15. Glucose-6-phosphate dehydrogenase (G6PD) deficiency and senile cataract in a Sardinian male population, Italy.

    Science.gov (United States)

    Pinna, Antonio; Pes, Adele; Zinellu, Angelo; Carta, Arturo; Solinas, Giuliana

    2009-01-01

    There is still no general agreement on the role of G6PD deficiency in the pathogenesis of cataract. The purpose of this study was to determine the prevalence of G6PD deficiency in men with senile cataract from Northern Sardinia, Italy, and to compare it with the prevalence rate of G6PD deficiency in the general population of the same area. G6PD activity was determined by using a quantitative method. G6PD blood levels were measured in 1,620 men with cataract. The control group consisted of 1,646 apparently healthy male subjects from the same area. All patients were of Sardinian origin. The Z or Student's t test was used, when appropriate, to determine differences between groups. The odds ratio (OR) with 95% confidence interval was used to evaluate the association between age-related cataract and G6PD deficiency. G6PD deficiency was found in 133 (8.2%) out of 1,620 patients with cataract and in 120 (7%) out of 1,646 control subjects. Differences in G6PD prevalence between cataract patients and controls were not statistically significant (P=0.64). There was no age-related statistical difference between G6PD deficient and normal patients with cataract. No statistically significant association between age-related cataract and G6PD deficiency was found (OR=1.14; 95% confidence interval: 0.88-1.47). The results of this large study suggest that male patients with G6PD deficiency in the Sardinian population do not have a higher risk of developing presenile cataract. G6PD deficiency does not represent a pathogenetic factor for early cataract formation, at least not in the Northern part of Sardinia.

  16. Serum antioxidant vitamins and risk of cataract.

    Science.gov (United States)

    Knekt, P; Heliövaara, M; Rissanen, A; Aromaa, A; Aaran, R K

    1992-12-05

    To investigate serum concentrations of alpha tocopherol, beta carotene, retinol, and selenium for their prediction of end stage cataract. A case-control study, nested within a cohort study, based on the linkage of records of subjects aged 40-83 from a health survey with those from the national Finnish hospital discharge register. 47 patients admitted to ophthalmological wards for senile cataract over 15 years and two controls per patient individually matched for sex, age, and municipality. Concentration of serum micronutrients, development of cataract according to whether operation was performed. Low serum concentrations of antioxidant vitamins predicted the development of senile cataract, the odds ratio between the lowest third and the two higher thirds of the distribution of serum concentrations of alpha tocopherol and beta carotene being 1.9 (95% confidence interval 0.9 to 4.1) and 1.7 (0.8 to 3.8), respectively. Patients with both alpha tocopherol and beta carotene concentrations in the lowest third had an odds ratio of 2.6 (1.0 to 6.8) of cataract compared with subjects in the top two thirds. The associations were strengthened by adjustment for potential confounding factors such as occupation, smoking, blood pressure, serum cholesterol concentration, body mass index, and diabetes. No association was found between the serum concentrations of selenium, retinol, and retinol binding protein and the risk of cataract. Low serum concentrations of the antioxidant vitamins alpha tocopherol and beta carotene are risk factors for end stage senile cataract. Controlled trials of the role of antioxidant vitamins in cataract prevention are therefore warranted.

  17. Numerical and experimental study of radiation induced conductivity change of carbon nanotube filled polymers

    Science.gov (United States)

    Liu, Fangjun; Sun, Yonghai; Sun, Weijie; Sun, Zhendong; Yeow, John T. W.

    2017-06-01

    Measuring the conductivity changes of sensing materials to detect a wide range of radiation energy and dosage is one of the major sensing mechanisms of radiation sensors. Carbon nanotube (CNT) filled composites are suitable for sensing radiation because of the extraordinary electrical properties of CNTs and the CNT-network formed inside the polymer matrix. Although the use of CNT-based nanocomposites as potential radiation sensing materials has been widely studied, there is still a lack of theoretical models to analyze the relationship between electrical conductivity and radiation dosages. In this article, we propose a 3D model to describe the electrical conductivity of CNT-based nanocomposites when being irradiated by ionizing radiation. The Monte Carlo method has been employed to calculate radiation intensity, CNT concentration and alignment’s influence on the electrical conductivity. Our simulation shows a better agreement when CNT loading is between the percolation threshold and 3% volume fraction. Radiation experiments have been performed to verify the reliability of our model to illustrate a power function relationship between the electrical conductivity of a CNT-filled polymer and radiation intensity. In addition, the predicted alignment to obtain the best sensitivity for radiation sensing has been discussed to help with CNT-network building in the fabrication process.

  18. Improvement of the experimental content in Laser Principle and its Application

    Science.gov (United States)

    Niu, Chun-hui; Lang, Xiao-ping; Lv, Yong; Meng, Hao

    2017-08-01

    Experimental teaching content of Laser Principle and Its Application is proposed to improve from experimental teaching devices and experimental guide book. At first, a experimental system of laser-diode-pumped solid-state laser is designed and manufactured. Separate optical components are adopted in the designed experimental system and students can put these optical components on every place and their ability to establish and adjust optical path can be enhanced. Moreover, experimental education outline of Laser Principle and Its Application is revised and improved. At last, experimental guide book for the designed and manufactured experimental device is written. The experimental teaching innovation will improve experimental teaching effect and quality of Laser Principle and Its Application.

  19. [Secondary cataract treatment with laser YAG-ND].

    Science.gov (United States)

    Pop, I; Petroi, Corina; Coroi, Mihaela; Ban, Claudia; Roiu, G; Stepan, Elena; Nistoran, Simona; Hânciu, Dana

    2002-01-01

    The purpose of the study is to present the favorable results of YAG: Nd laser capsulotomy for the treatment of secondary opacification of the posterior capsule, in our department. A 3 years retrospective study was performed. For 1440 cataract operations, most of them extracapsular extractions with PMMA IOL placed in the posterior chamber (ciliary sulcus or capsular bag), 285 laser capsulotomies were done. The results are presented statistically, including sex and age distribution, type of cataract surgery and implant, treatment protocol (number of sessions, number of impulses per session, energy per impulse) and complications. The frequency of secondary capsular opacification in our study is 19.78%. It is most important in the age group 60-70 years, where the surgery for cataract is performed more often. Capsulotomy was done after extracapsular extraction with IOL placed in the posterior chamber, but especially after extracapsular extraction without implant placement or with complications that have permitted only the use of an anterior chamber implant. Capsulotomy is performed in only one session in 88% of the cases. The energy per impulse is usually 3-5 mJ and the mean number of impulses per session is 10-30. There are few complications: transient elevation of intraocular pressure in 14.73%, discrete laser marks on the implant in 8.77% and moderate iritis in 1% of the cases. YAG: Nd laser capsulotomy appears to be a safe and efficient method of treating secondary cataract; it improved visual acuity in all cases, if different ocular pathology had not influenced it.

  20. Craniofacial Microsomia: Goldenhar Syndrome in Association with Bilateral Congenital Cataract.

    Science.gov (United States)

    Shrestha, U D; Adhikari, S

    2015-01-01

    Craniofacial microsomia (CFM) includes a spectrum of malformations primarily involving structures derived from the first and second branchial arches. Patients with hemifacial microsomia and epibulbar dermoids are said to have Goldenhar syndrome (GHS). Four-month-old boy with whitish pupillary reflex presented with the features of GHS in pediatric ophthalmology clinic. The child had ocular and auricular manifestations. There were no vertebral anomalies, but he had bilateral congenital cataract. The peculiarity of this case is the presence of the bilateral total congenital cataract, in association with CFM. There is absence of epibulbar dermoid or lipodermoid in the eyes, although the child had features of GHS. In addition to it, anesthetic intubation was smooth in this case. Any case diagnosed with CFM and/or GHS needs treatment through multidisciplinary approach, consultation in ophthalmology department is one of them.

  1. Craniofacial Microsomia: Goldenhar Syndrome in Association with Bilateral Congenital Cataract

    Directory of Open Access Journals (Sweden)

    U. D. Shrestha

    2015-01-01

    Full Text Available Craniofacial microsomia (CFM includes a spectrum of malformations primarily involving structures derived from the first and second branchial arches. Patients with hemifacial microsomia and epibulbar dermoids are said to have Goldenhar syndrome (GHS. Four-month-old boy with whitish pupillary reflex presented with the features of GHS in pediatric ophthalmology clinic. The child had ocular and auricular manifestations. There were no vertebral anomalies, but he had bilateral congenital cataract. The peculiarity of this case is the presence of the bilateral total congenital cataract, in association with CFM. There is absence of epibulbar dermoid or lipodermoid in the eyes, although the child had features of GHS. In addition to it, anesthetic intubation was smooth in this case. Any case diagnosed with CFM and/or GHS needs treatment through multidisciplinary approach, consultation in ophthalmology department is one of them.

  2. Lung transplantation: is it still an experimental procedure?

    Science.gov (United States)

    Boffini, Massimo; Ranieri, Vito M; Rinaldi, Mauro

    2010-02-01

    The number of lung transplants performed worldwide is low and early and late results are worse in comparison with other solid organ transplants. The present review will focus on these two aspects analyzing the causes and describing the possible strategies to overcome these limitations. The use of grafts from marginal and from nonheart-beating donors may increase the number of lung transplantation (LTx) with good results. Implementation of donor protocol and optimization of donor management have been reported to be effective in increasing the pool of suitable grafts. Ex-vivo reconditioning technique may be also helpful to better evaluate and recondition usually rejected lungs. This may allow a significant increase in the number of lung transplants performed worldwide. Early and late results of LTx are mainly affected by primary graft dysfunction and the onset of obliterative bronchiolitis. Different strategies have been adopted to reduce the incidence of these two complications with controversial results. LTx maintains some features of experimental procedure especially in terms of number of performed procedures and early and late results. The various strategies to overcome the limited number of available grafts appear effective but not universally applied and accepted. The different treatments of PDG and obliterative bronchiolitis are still disappointing. To date, the onset of PDG and obliterative bronchiolitis after LTx still significantly impacts on outcomes. A better understanding of the underlying mechanisms in the pathogenesis of primary graft dysfunction and obliterative bronchiolitis may provide improved therapeutic strategies.

  3. Experimental studies on pathogenesis of the brain radiation injury in early stage

    Energy Technology Data Exchange (ETDEWEB)

    Ye Tian [Suzhou Medical Coll., Jiangsu (China). 2nd Affiliated Hospital; Shiyao Bao; Weibo Yin; Chunfeng Liu; Zhilin Zhang

    2000-05-01

    To investigate the pathogenesis of the brain radiation injury in the early stage, a series of experiments were performed as below. The SD rats halfbrain were irradiated by the single dose of 10, 20, and 30 Gy of 4 MeV electron, all those experiments were performed in 1 day to 3 months after radiation. The neurological symptoms, the weight and the skin response inside the field of all the rats were evaluated sequentially. The measurement of regional cerebral blood flow (rCBF) using hydrogen gas generated by electrolysis, the calculation of the brain water content percentage with wet-dry weight formula. The DNA contents and the quantities of bcl-2 protein were analyzed by flow cytometry. The brain histological sections were scanned to assess the present or absence of white matter necrosis in the region of hippocampus, and then the hippocampus region was observed for the morphological changes of the blood vessel, neuroglial, and the neurons. Some of the data were analyzed by the Student t test. Intra-portal alopecia was observed in all rats which received 30 Gy and some rats which received 20 Gy, the abnormal neurological signs were not found in all the rats, but the tend of weight increase was less pronounced in 1-3 months in the irradiated rats than those unirradiated. By comparison the unirradiated hemisphere, the rCBF of the contralateral brain decreased in most of the rats. In 20 Gy and 30 Gy groups, rCBF decreased areas expand gradually along with the prolong of observation time, from the nucleus caudate putamen, to the frontal cortex and then the hippocampus, the rCBF of whole the irradiated hemibrain was reduced significantly at 3 month after radiation. The water content of the irradiated halfbrain increased progressively, it means the brain edema exists in the meantime. By comparison the unirradiation halfbrain, the apoptosis of the hippocampus cells in the irradiated brain increased, and the expression of bcl-2 protein decreased at the meantime, and those

  4. A comparison of experimental and estimated data analyses of solar radiation, in Adiyaman, Turkey

    OpenAIRE

    Bozkurt, Ismail; Calis, Nazif; Sogukpinar, Haci

    2015-01-01

    The world's main energy source is the sun. Other energy sources are caused directly or indirectly from the sun. Turkey has a rich potential in terms of solar energy and interest in solar power systems is increasing in the rapidly evolving technology. In all of the solar energy studies needs solar radiation data but solar radiation measurements are not possible on each area. Therefore, estimation of the solar radiation by using a variety of methods are emerging importance. In this study, ...

  5. Ionizing radiation processing and its potential in advancing biorefining and nanocellulose composite materials manufacturing

    Science.gov (United States)

    Postek, Michael T.; Poster, Dianne L.; Vládar, András E.; Driscoll, Mark S.; LaVerne, Jay A.; Tsinas, Zois; Al-Sheikhly, Mohamad I.

    2018-02-01

    Nanocellulose is a high value material that has gained increasing attention because of its high strength, stiffness, unique photonic and piezoelectric properties, high stability and uniform structure. Through utilization of a biorefinery concept, nanocellulose can be produced in large volumes from wood at relatively low cost via ionizing radiation processing. Ionizing radiation causes significant break down of the polysaccharide and leads to the production of potentially useful gaseous products such as H2 and CO. The application of radiation processing to the production of nanocellulose from woody and non-wood sources, such as field grasses, bio-refining by-products, industrial pulp waste, and agricultural surplus materials remains an open field, ripe for innovation and application. Elucidating the mechanisms of the radiolytic decomposition of cellulose and the mass generation of nanocellulose by radiation processing is key to tapping into this source of nanocelluose for the growth of nanocellulostic-product development. More importantly, understanding the structural break-up of the cell walls as a function of radiation exposure is a key goal and only through careful, detailed characterization and dimensional metrology can this be achieved at the level of detail that is needed to further the growth of large scale radiation processing of plant materials. This work is resulting from strong collaborations between NIST and its academic partners who are pursuing the unique demonstration of applied ionizing radiation processing to plant materials as well as the development of manufacturing metrology for novel nanomaterials.

  6. Cation and water transport during maturation of cortical cataract

    Directory of Open Access Journals (Sweden)

    Khurana A

    1988-01-01

    Full Text Available Water, electrolyte and free amino acid content of the crystalline lens were estimated in patients with nuclear cataract and in immature, mature and hypermature cortical cataract groups. Wet weight/dry weight and sodium/potassium ratios were calculated. Sodium, potassium ratio was significantly higher in immature cortical cataract when compared with the nuclear cataract. With maturation of the cortical cataract, the lens was found to be more hydrated and there was accumulation of sodium. However, free amino acid content of the lens decreased. A hypothesis has been proposed for alterations in the active transport pump of the crystalline lens during the maturation of the cortical cataract.

  7. Influence of Water with Modified Isotope Structure on Development of Radiation Damage in Experimental Animals

    Science.gov (United States)

    Rakov, D. V.; Fedorenko, B. S.; Sinyak, Yu. E.

    begin table htbp begin center begin tabular p 442pt hline As the duration of space missions increases the problem of durability of space crews and their resistivity to space flight factors becomes more important The purpose of the present work was to study the radioprotective effects of lowered deuterium content water in experimental animals after repeated exposures to low doses of gamma radiation Both male and female adult mice of NAAoN57Al6 F1 and BALB c lines were exposed to 0 25 0 5 and 1 0 Gy of 60 Co gamma rays by multiple fractions The dose rate was 0 32 Gy min Starting from one month prior to the first irradiation fraction till the end of the experiment the animals were only supplied with lowered deuterium content water ad libitum The control group of mice consumed tap water only The mice were sacrificed by means of cervical dislocation within one month after finishing the last irradiation fraction The following parameters were registered the weight of body thymus and spleen number of leucocytes blood formula number of caryocytes in femur bone marrow cytogenetic lesions in nucleated bone marrow cells The water with lowered deuterium content was produced by means of electrolysis with a special device in the Institute for Biomedical Problems par A long-term consumption of water with lowered deuterium content by irradiated mice was found to result in lower levels of depletion of peripheral blood leucocytes and bone marrow cells in a decrease in the yield of cytogenetic aberrations and in a less intensive reduction of the mass

  8. Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract.

    Science.gov (United States)

    Mathew, Milan C; Ervin, Ann-Margret; Tao, Jeremiah; Davis, Richard M

    2012-06-13

    Age-related cataract is a major cause of visual impairment in the elderly. Oxidative stress has been implicated in its formation and progression. Antioxidant vitamin supplementation has been investigated in this context. To assess the effectiveness of antioxidant vitamin supplementation in preventing and slowing the progression of age-related cataract. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 2), MEDLINE (January 1950 to March 2012), EMBASE (January 1980 to March 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 2 March 2012. We also checked the reference lists of included studies and ongoing trials and contacted investigators to identify eligible randomized trials. We included only randomized controlled trials in which supplementation with one or more antioxidant vitamins (beta-carotene, vitamin C and vitamin E) in any form, dosage or combination for at least one year was compared to another antioxidant vitamin or to placebo. Two authors extracted data and assessed trial quality independently. We pooled results for the primary outcomes, i.e., incidence of cataract and incidence of cataract extraction. We did not pool results of the secondary outcomes - progression of cataract and loss of visual acuity, because of differences in definitions of outcomes and data presentation. We pooled results by type of cataract when data were available. We did not perform a sensitivity analysis. Nine trials involving 117

  9. Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract

    Science.gov (United States)

    Mathew, Milan C; Ervin, Ann-Margret; Tao, Jeremiah; Davis, Richard M

    2013-01-01

    Background Age-related cataract is a major cause of visual impairment in the elderly. Oxidative stress has been implicated in its formation and progression. Antioxidant vitamin supplementation has been investigated in this context. Objectives To assess the effectiveness of antioxidant vitamin supplementation in preventing and slowing the progression of age-related cataract. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 2), MEDLINE (January 1950 to March 2012), EMBASE (January 1980 to March 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to March 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 2 March 2012. We also checked the reference lists of included studies and ongoing trials and contacted investigators to identify eligible randomized trials. Selection criteria We included only randomized controlled trials in which supplementation with one or more antioxidant vitamins (beta-carotene, vitamin C and vitamin E) in any form, dosage or combination for at least one year was compared to another antioxidant vitamin or to placebo. Data collection and analysis Two authors extracted data and assessed trial quality independently. We pooled results for the primary outcomes, i.e., incidence of cataract and incidence of cataract extraction. We did not pool results of the secondary outcomes - progression of cataract and loss of visual acuity, because of differences in definitions of outcomes and data presentation. We pooled results by type of cataract when data

  10. Job satisfaction and its relationship to Radiation Protection Knowledge, Attitude and Practice (RPKAP) of Iranian radiation workers.

    Science.gov (United States)

    Alavi, S S; Dabbagh, S T; Abbasi, M; Mehrdad, R

    2017-01-23

    This study aimed to find the association between job satisfaction and radiation protection knowledge, attitude and practice of medical radiation workers occupationally exposed to ionizing radiation. In this crosssectional study, 530 radiation workers affiliated to Tehran University of Medical Sciences completed a knowledge, attitude and practice questionnaire on protecting themselves against radiation and Job Descriptive Index as a job satisfaction measure during May to November 2014. Opportunities for promotion (84.2%) and payment (91.5%) were the most important factors for dissatisfaction. Radiation workers who were married, had more positive attitudes toward protecting themselves against radiation, and had higher level of education accounted for 15.8% of the total variance in predicting job satisfaction. In conclusion, medical radiation workers with a more positive attitude toward self-protection against radiation were more satisfied with their jobs. In radiation environments, improving staff attitudes toward their safety may be considered as a key strategy to increase job satisfaction.

  11. Earth radiation budget from a surface perspective and its representation in CMIP5 models

    Science.gov (United States)

    Wild, M.

    2012-04-01

    The genesis and evolution of Earth's climate is largely regulated by the global energy balance. Despite the central importance of the global energy balance for the climate system and climate change, substantial uncertainties still exist in the quantification of its different components, and their representation in climate models (e.g., Wild et al. 1998 Clim. Dyn., Wild 2008 Tellus). While the net radiative energy flow in and out of the climate system at the top of atmosphere (TOA) is known with considerable accuracy from new satellite programs such as CERES, much less is known about the energy distribution within the climate system and at the Earth surface. Here we use direct surface observations from the Baseline Surface Radiation Network (BSRN) and the Global Energy Balance Archive (GEBA) to provide better constraints on the surface radiative components as well as to investigate their temporal changes. We analyze radiation budgets of the latest generation of global climate models as used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and in the upcoming Fifth IPCC assessment report (IPCCAR5). Compared to a comprehensive set of surface observations, the CMIP5 models overestimate the shortwave radiation incident at the surface by 5-10 Wm-2 on average, due to a lack of absorption in the atmosphere. This suggests that the best estimate for the global mean absorbed shortwave radiation at the surface should be lower than the simulated estimates, which are on average slightly below 170 Wm-2, so that a value of no more than 160 Wm-2 might be the most realistic estimate for the global mean absorbed shortwave radiation at the surface. In contrast, the longwave downward radiation at the surface is underestimated by a similar amount in these models, suggesting that the best estimate for the global mean downward longwave radiation should be rather around 345 Wm-2 than the model average of 338 Wm-2. There is further increasing evidence from the direct

  12. Prevalence of myopic shifts among patients seeking cataract surgery

    Directory of Open Access Journals (Sweden)

    Rafael Iribarren

    2013-06-01

    Full Text Available Modern cataract surgery by phacoemulsification is a widely accepted procedure with a rapid recovery time. The prescription of specific intraocular lens, implanted during surgery, makes it possible to anticipate whether the patient will need reading glasses after the procedure. The present study analyses a sample of cataract surgery patients to show the frequency of myopic shifts related to nuclear opacity, which can result in clear near vision before surgery. A non-selected sample of consecutive patients who underwent elective cataract surgery in a private clinic was studied retrospectively. The myopic shift in refraction was assessed by comparing the old prescription with the spectacle correction at the time of interviewing.The mean age of the 229 subjects studied was 71.5 ± 10.4 years (109, 47.6%, males. A myopic shift in refraction, defined as at least - 0.5 diopters, was present in 37.1% of subjects (95% CI: 30.8%-43.4%. The mean change in refraction in these subjects was -2.52 ± 1.52 diopters. The percentage of subjects who had developed a myopic shift was significantly greater in those who presented greater nuclear opalescence. There were also differences in the mean myopic shift by refractive group, with the emmetropes having the greatest myopic shift. In this study of patients seeking cataract surgery in a clinical setting, more than one third had myopic shifts in refraction. This must be taken into account in order that patients maintain the benefit of clear near vision after surgery.

  13. Effects of artificial ultraviolet-B radiation on experimental aquatic microcosms

    NARCIS (Netherlands)

    De Lange, H.J.; Verschoor, A.M.; Gylstra, R.; Cuppen, J.G.M.; Van Donk, E.

    1999-01-01

    1. The effects of prolonged ultraviolet-B (UVB) radiation on freshwater communities were studied in indoor microcosms (600 L) with artificial light sources, simulating a clear, shallow, mesotrophic aquatic ecosystem. A range of six intensities (in duplicate) of UVB radiation, ranging from 0

  14. Predicting refractive aniseikonia after cataract surgery in anisometropia.

    Science.gov (United States)

    Gobin, Laure; Rozema, Jos J; Tassignon, Marie-José

    2008-08-01

    To propose a comprehensive classification of anisometropia, a method to calculate the theoretical related aniseikonia (objective aniseikonia) and a purpose-designed eikonometer to measure aniseikonia psychophysically (subjective aniseikonia). University Hospital Antwerp, Department of Ophthalmology, Edegem, Belgium. The occurrence of anisometropia was evaluated in 263 patients scheduled for cataract surgery. Subjective aniseikonia was evaluated in 77 healthy patients. The theoretical model was validated to calculate objective aniseikonia by implementing data from the literature. Ultimately, an aniseikogram was developed and its practical use illustrated by 4 clinical cases of anisometropia. In a population of 263 patients, the total incidence of anisometropia was 7.6%, with a dominance of axial anisometropia. Subjective aniseikonia between 2% and 4% was found in 3.0% to 7.5% of the cases, depending on the refractive error. The correlation coefficient between objective and subjective aniseikonia was good (R(2) = 0.82). Analysis of 4 clinical cases illustrated the calculated preoperative and postoperative aniseikonia in 4 types of anisometropia planned for lens removal. Anisometropia is not a rare condition and should be assessed before cataract surgery. A comprehensive method to calculate the objective aniseikonia and to measure the subjective aniseikonia in anisometropia was proposed. If cataract surgery is considered in anisometropic patients, a postoperative aniseikonia of 4% or more may be induced in the case of emmetropization. A method to calculate the intraocular lens power resulting in an acceptable postoperative aniseikonia, especially in axial anisometropic patients, is also proposed.

  15. Changes in corneal hysteresis after clear corneal cataract surgery.

    Science.gov (United States)

    Hager, Annette; Loge, Kristina; Füllhas, Marc-Oliver; Schroeder, Bernd; Grossherr, Martin; Wiegand, Wolfgang

    2007-09-01

    To assess the changes in corneal hysteresis (CH) as measured by the Ocular Response Analyzer (ORA; Reichert Ophthalmic Instruments, Buffalo, New York, USA) to describe the influence of clear corneal cataract surgery on corneal viscoelastic properties and intraocular pressure (IOP) measured by noncontact tonometry (NCT) and Goldmann applanation tonometry (GAT). Retrospective, interventional, comparative study. One hundred and one eyes of 101 consecutive patients who underwent routine clear corneal cataract surgery were evaluated. CH, NCT, and central corneal thickness (CCT) were measured by ORA before surgery and at postoperative day 1. A control group of 48 pseudophakic eyes (surgery >3 months previously) was included. CCT increased from 556.82 +/- 32.5 microm before surgery to 580.26 +/- 45.5 microm after surgery (P corneal cataract surgery, CH is diminished, whereas CCT is increased significantly. Postoperative corneal edema leads to a change of corneal viscoelastic properties, resulting in a lower damping capacity of the cornea. It is supposed that GAT and NCT measurements are significantly different because of postoperative changes in viscoelastic properties of the cornea.

  16. [Is it possible a bioethics based on the experimental evidence?].

    Science.gov (United States)

    Pastor, Luis Miguel

    2013-01-01

    For years there are different types of criticism about principialist bioethics. One alternative that has been proposed is to introduce empirical evidence within the bioethical discourse to make it less formal, less theoretical and closer to reality. In this paper we analyze first in synthetic form diverse alternative proposals to make an empirical bioethics. Some of them are strongly naturalistic while others aim to provide empirical data only for correct or improve bioethical work. Most of them are not shown in favor of maintaining a complete separation between facts and values, between what is and what ought to be. With different nuances these proposals of moderate naturalism make ethical judgments depend normative social opinion resulting into a certain social naturalism. Against these proposals we think to make a bioethics in that relates the empirical facts with ethical duties, we must rediscover empirical reality of human action. Only from it and, in particular, from the activity of discernment that makes practical reason, when judged on the object of his action, it is possible to integrate the mere descriptive facts with ethical judgments of character prescriptive. In conclusion we think that it is not possible to perform bioethics a mode of empirical science, as this would be contrary to natural reason, leading to a sort of scientific reductionism. At the same time we believe that empirical data are important in the development of bioethics and to enhance and improve the innate ability of human reason to discern good. From this discernment could develop a bioethics from the perspective of ethical agents themselves, avoiding the extremes of an excessive normative rationalism, accepting empirical data and not falling into a simple pragmatism.

  17. Modified Schr\\"odinger equation, its analysis and experimental verification

    OpenAIRE

    Shnaid, Isaac

    2012-01-01

    According to classical non-relativistic Schr\\"odinger equation, any local perturbation of wave function instantaneously affects all infinite region, because this equation is of parabolic type, and its solutions demonstrate infinite speed of perturbations propagation. From physical point of view, this feature of Schr\\"odinger equation solutions is questionable. According to relativistic quantum mechanics, the perturbations propagate with speed of light. However when appropriate mathematical pr...

  18. Experimental Investigation of Space Radiation Processing in Lunar Soil Ilmenite: Combining Perspectives from Surface Science and Transmission Electron Microscopy

    Science.gov (United States)

    Christoffersen, R.; Keller, L. P.; Rahman, Z.; Baragiola, R.

    2010-01-01

    Energetic ions mostly from the solar wind play a major role in lunar space weathering because they contribute structural and chemical changes to the space-exposed surfaces of lunar regolith grains. In mature mare soils, ilmenite (FeTiO3) grains in the finest size fraction have been shown in transmission electron microscope (TEM) studies to exhibit key differences in their response to space radiation processing relative to silicates [1,2,3]. In ilmenite, solar ion radiation alters host grain outer margins to produce 10-100 nm thick layers that are microstructurally complex, but dominantly crystalline compared to the amorphous radiation-processed rims on silicates [1,2,3]. Spatially well-resolved analytical TEM measurements also show nm-scale compositional and chemical state changes in these layers [1,3]. These include shifts in Fe/Ti ratio from strong surface Fe-enrichment (Fe/Ti >> 1), to Fe depletion (Fe/Ti < 1) at 40-50 nm below the grain surface [1,3]. These compositional changes are not observed in the radiation-processed rims on silicates [4]. Several mechanism(s) to explain the overall relations in the ilmenite grain rims by radiation processing and/or additional space weathering processes were proposed by [1], and remain under current consideration [3]. A key issue has concerned the ability of ion radiation processing alone to produce some of the deeper- penetrating compositional changes. In order to provide some experimental constraints on these questions, we have performed a combined X-ray photoelectron spectroscopy (XPS) and field-emission scanning transmission electron (FE-STEM) study of experimentally ion-irradiated ilmenite. A key feature of this work is the combination of analytical techniques sensitive to changes in the irradiated samples at depth scales going from the immediate surface (approx.5 nm; XPS), to deeper in the grain interior (5-100 nm; FE-STEM).

  19. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  20. The role of small incision suture-less cataract surgery in the developed world.

    Science.gov (United States)

    Ruit, Sanduk; Gurung, Reeta; Vyas, Shyam

    2018-01-01

    Manual small incision cataract surgery (MSICS) has recently gone through much refinement and fine tuning. It is often taken as an alternate option for phacoemulsification, especially in developing country. This review will present some insight on its applications especially for developed nations. The role of MSCIS in tackling complex cataracts with stony hard nucleus is fairly established. The role of training residents with MSCIS has certain advantages though debatable. MSCIS is much faster and cost-effective surgical technique often possible in suboptimal condition and avoids the capital and maintenance cost of phacoemulsification. The visual outcome and postoperative complications in both phacoemulsification and MSCIS are comparable. Slightly greater astigmatism in MSICS can be lessened with a slight modification of surgical technique. The successful application of MSCIS in large public health programmes has successfully helped to increase the cataract surgical rate and quality. It is the technique of choice for blindness control programme in developing country. MSICS is established as safe and cost-effective procedure in developing country with results as good as phaoemulsification. Although it may not be the best option for developed nations, it is a valuable skill especially for surgical conversion and to deal with complex and advance cataract cases. Hence, it should be a part of resident training programme in developed world and it should be in the armamentarium of every cataract surgeon.

  1. The 2009 devaluation of radiosurgery and its impact on the neurosurgery-radiation oncology partnership.

    Science.gov (United States)

    Heilbrun, M Peter; Adler, John R

    2010-07-01

    Neurosurgeons, radiation oncologists, and, increasingly, other surgical specialists recognize that radiosurgery is an important tool for managing selected disorders throughout the body. The partnership between neurosurgeons and radiation oncologists has resulted in collaborative studies that have established the clinical benefits of radiosurgery. Today, however, a range of political and financial issues is straining this relationship and thereby undermining the practice of radiosurgery. Neurosurgeons and radiation oncologists recently restricted the definition of radiosurgery to include only cranial- and spine-focused radiation treatments. Meanwhile, organized radiation oncology decided unilaterally that radiosurgery administered to other parts of the body would be termed stereotactic body radiation therapy. Finally, neurosurgical and radiation oncology coding experts developed new Current Procedural Terminology codes for cranial vault and spine radiosurgery, which were approved for use by the Relative Value Scale Update Committee as of 2009. The authors suggest that the neurosurgery strategy-which included 1) reasserting that all of the tasks of a radiosurgery procedure remain bundled, and 2) agreeing to limit the definition of radiosurgery to cranial vault and spine-has failed neurosurgeons who perform radiosurgery, and it may jeopardize patient access to this procedure in the future. The authors propose that all of the involved medical specialties recognize that the application of image-guided, focused radiation therapy throughout the body requires a partnership between radiation and surgical disciplines. They also urge surgeons to reexamine their coding methods, and they maintain that Current Procedural Terminology codes should be consistent across all of the different specialties involved in these procedures. Finally, surgeons should consider appropriate training in medical physics and radiobiology to perform the tasks involved in these specific procedures

  2. The carbon footprint of cataract surgery.

    Science.gov (United States)

    Morris, D S; Wright, T; Somner, J E A; Connor, A

    2013-04-01

    Climate change is predicted to be one of the largest global health threats of the 21st century. Health care itself is a large contributor to carbon emissions. Determining the carbon footprint of specific health care activities such as cataract surgery allows the assessment of associated emissions and identifies opportunities for reduction. To assess the carbon footprint of a cataract pathway in a British teaching hospital. This was a component analysis study for one patient having first eye cataract surgery in the University Hospital of Wales, Cardiff. Activity data was collected from three sectors, building and energy use, travel and procurement. Published emissions factors were applied to this data to provide figures in carbon dioxide equivalents (CO2eq). The carbon footprint for one cataract operation was 181.8 kg CO2eq. On the basis that 2230 patients were treated for cataracts during 2011 in Cardiff, this has an associated carbon footprint of 405.4 tonnes CO2eq. Building and energy use was estimated to account for 36.1% of overall emissions, travel 10.1% and procurement 53.8%, with medical equipment accounting for the most emissions at 32.6%. This is the first published carbon footprint of cataract surgery and acts as a benchmark for other studies as well as identifying areas for emissions reduction. Within the procurement sector, dialogue with industry is important to reduce the overall carbon footprint. Sustainability should be considered when cataract pathways are designed as there is potential for reduction in all sectors with the possible side effects of saving costs and improving patient care.

  3. Secondary glaucoma after pediatric cataract surgery

    Directory of Open Access Journals (Sweden)

    Yasin Çinar

    2013-04-01

    Full Text Available AIM:To determine the incidence and risk factors of secondary glaucoma after pediatric cataract surgery. METHODS: Two hundred and forty nine eyes of 148 patients underwent cataract surgery without intraocular lens (IOL implantation (group 1, and 220 eyes of 129 patients underwent cataract surgery with IOL implantation (group 2 retrospectively, were evaluated between 2000 and 2011.The outcome measure was the presence or absence of post-cataract surgery glaucoma, defined as an intraocular pressure (IOP ≥26mmHg, as measured on at least two occasions along with corneal or optic nerve changes. RESULTS: The mean follow-up periods of group 1 and 2 were (60.86±30.95 months (12-123 months and (62.11±31.29 months (14-115 months respectively. In group 1, 12 eyes of 8 patients (4.8% developed glaucoma. None of the patients developed glaucoma after surgery in group 2. The mean age of the patients at the cataract surgery was (2.58±0.90 months (1 month-4 months and the average period for glaucoma development after surgery was (9.50±4.33 months (4-16 months in group 1. Three of the 12 glaucomatous eyes were controlled with antiglaucomatous medication and 9 eyes underwent trabeculectomy+mitomycin C surgery. One patient underwent a second trabeculectomy + mitomycin C operation for both of his eyes. CONCLUSION: The incidence of glaucoma after pediatric cataract surgery is very low in patients in whom IOL is implanted. The aphakic eyes after pediatric cataract surgery are at an increased risk for glaucoma development particularly if they underwent surgery before 4 months of age.

  4. Theoretical and experimental radiation effectiveness of the free radical dosimeter alanine to irradiation with heavy charged particles

    DEFF Research Database (Denmark)

    Hansen, Jørgen-Walther; Olsen, K. J.

    1985-01-01

    -LET radiations of 60Co .gamma. rays, 4 and 16 MV X rays, and 6, 10, and 20 MeV electrons was compared with theoretical RE values derived from a model based on track structure theory of heavy charged particles. The ion beams covered a range in initial LET of 27-20,200 MeVcm2/g, and the experimental RE decreased...

  5. Study of Radiative Forcing of Dust Aerosols and its impact on Climate Characteristics

    KAUST Repository

    Qureshi, Fawwad H

    2012-12-01

    The purpose of following project is to study the effect of dust aerosols on the radiative forcing which is directly related to the surface temperature. A single column radiative convective model is used for simulation purpose. A series of simulations have been performed by varying the amount of dust aerosols present in the atmosphere to study the trends in ground temperature, heating rate and radiative forcing for both its longwave and shortwave components. A case study for dust storm is also performed as dust storms are common in Arabian Peninsula. A sensitivity analyses is also performed to study the relationship of surface temperature minimum and maximum against aerosol concentration, single scattering albedo and asymmetry factor. These analyses are performed to get more insight into the role of dust aerosols on radiative forcing.

  6. Hormetic Response to Low-Dose Radiation: Focus on the Immune System and Its Clinical Implications

    Directory of Open Access Journals (Sweden)

    Jiuwei Cui

    2017-01-01

    Full Text Available The interrelationship between ionizing radiation and the immune system is complex, multifactorial, and dependent on radiation dose/quality and immune cell type. High-dose radiation usually results in immune suppression. On the contrary, low-dose radiation (LDR modulates a variety of immune responses that have exhibited the properties of immune hormesis. Although the underlying molecular mechanism is not fully understood yet, LDR has been used clinically for the treatment of autoimmune diseases and malignant tumors. These advancements in preclinical and clinical studies suggest that LDR-mediated immune modulation is a well-orchestrated phenomenon with clinical potential. We summarize recent developments in the understanding of LDR-mediated immune modulation, with an emphasis on its potential clinical applications.

  7. An entrepreneurial physics method and its experimental test

    Science.gov (United States)

    Brown, Robert

    2012-02-01

    As faculty in a master's program for entrepreneurial physics and in an applied physics PhD program, I have advised upwards of 40 master and doctoral theses in industrial physics. I have been closely involved with four robust start-up manufacturing companies focused on physics high-technology and I have spent 30 years collaborating with industrial physicists on research and development. Thus I am in a position to reflect on many articles and advice columns centered on entrepreneurship. What about the goals, strategies, resources, skills, and the 10,000 hours needed to be an entrepreneur? What about business plans, partners, financing, patents, networking, salesmanship and regulatory affairs? What about learning new technology, how to solve problems and, in fact, learning innovation itself? At this point, I have my own method to propose to physicists in academia for incorporating entrepreneurship into their research lives. With this method, we do not start with a major invention or discovery, or even with a search for one. The method is based on the training we have, and the teaching we do (even quantum electrodynamics!), as physicists. It is based on the networking we build by 1) providing courses of continuing education for people working in industry and 2) through our undergraduate as well as graduate students who have gone on to work in industry. In fact, if we were to be limited to two words to describe the method, they are ``former students.'' Data from local and international medical imaging manufacturing industry are presented.

  8. Treatment outcome and risk analysis for cataract after radiotherapy of localized ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Hyun; Lee, Sea Won; Sung, Soo Yoon; Choi, Byung Oak [Dept. of Radiation Oncology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul, (Korea, Republic of)

    2017-09-15

    We retrospectively reviewed the results of radiotherapy for localized ocular adnexal MALT lymphoma (OAML) to investigate the risk factors of cataract. Sixty-seven patients with stage IE OAML treated with radiotherapy at Seoul St. Mary’s Hospital from 2001 to 2016 were included. Median treatment dose was 30 Gy. Lens protection was done in 52 (76%) patients. Radiation therapy (RT) extent was as follows: superficial (82.1%), tumor mass (4.5%), and entire orbital socket (13.4%). The risk factors for symptomatic cataract were analyzed using the Cox proportional hazard model. Median follow-up time was 50.9 months (range, 1.9 to 149.4 months). All patients were alive at the time of analysis. There were 7 recurrences and there was no local recurrence. Median time to recurrence was 40.4 months. There were 14 cases of symptomatic cataract. Dose >30 Gy had hazard ratio of 3.47 for cataract (p = 0.026). Omitting lens protection showed hazard ratio of 4.10 (p = 0.008). RT achieves excellent local control of ocular MALT lymphoma. Consideration of RT-related factors such as lens protection and radiation dose at the stage of RT planning may reduce the risk of RT-induced cataract after radiotherapy.

  9. The effect of health insurance reform on the number of cataract surgeries in Chongqing, China

    Directory of Open Access Journals (Sweden)

    Yuan Rongdi

    2011-03-01

    Full Text Available Abstract Background Cataracts are the leading cause of blindness in China, and poverty is a major barrier to having cataract surgery. In 2003, the Chinese government began a series of new national health insurance reforms, including the New Cooperative Medical Scheme (NCMS and the Urban Resident Basic Health Insurance scheme (URBMI. These two programs, combined with the previously existing Urban Employee Basic Health Insurance (UEBMI program, aimed to make it easier for individuals to receive medical treatment. This study reports cataract surgery numbers in rural and urban populations and the proportion of these who had health insurance in Chongqing, China from 2003 to 2008. Methods The medical records of a consecutive case series, including 14,700 eyes of 13,262 patients who underwent age-related cataract surgery in eight hospitals in Chongqing from January 1, 2003, to December 31, 2008, were analysed retrospectively via multi-stage cluster sampling. Results In the past six years, the total number of cataract surgeries had increased each year as had the number of patients with insurance. Both the number of surgeries and the number of insured patients were much higher in the urban group than in the rural group. The rate of increase in the rural group however was much higher than in the urban group, especially in 2007 and 2008. The odds ratios of having health insurance for urban vs. rural individuals were relatively stable from 2003 to 2006, but it decreased in 2007 and was significantly lower in 2008. Conclusions Health insurance appears to be an important factor associated with increased cataract surgery in Chongqing, China. With the implementation of health insurance, the number of Chongqing's cataract surgeries was increased year by year.

  10. Nuclear and Mitochondrial DNA of Age-Related Cataract Patients Are Susceptible to Oxidative Damage.

    Science.gov (United States)

    Erol Tinaztepe, Özlem; Ay, Mustafa; Eser, Eray

    2017-04-01

    Reactive oxygen species caused by oxidative stress are considered as an important risk factor in the pathogenesis of age-related cataract (ARC). In addition, it has been shown that DNA damage has a potential role in the pathogenesis of cataract. In this study, background DNA damage, oxidative stress-induced DNA damage, and repair of nuclear and mitochondrial DNA of peripheral blood mononuclear cells (PBMCs) of ARC patients were investigated. The study population included 30 age-matched and sex-matched controls with 30 ARC patients aged 50 years and older. Acute oxidative stress was induced by 200 µM H2O2. The DNA damage was determined using gene-specific quantitative PCR-based assay in DNA extracted from PBMCs, both at basal condition and after (0, 6, and 20 h) acute oxidative stress. Background level of mitochondrial DNA frequency was higher in cataract patients. The present study revealed that, for the first time, both nDNA and mtDNA of cataract patients were sensitive to the oxidative stress in comparison with healthy individuals. It was found that oxidative DNA damage in PBMCs was almost all repaired within 20 h. Also, time-dependent repair of nDNA and mtDNA damage was not different between cataract patients and healthy individuals. Our findings clearly demonstrate that both nDNA and mtDNA in cataract patients are susceptible to oxidative DNA damage and background level of mitochondrial DNA damage was higher. Also, these results suggest that oxidative DNA damage accumulation (especially mtDNA damage) can play a crucial role in pathogenesis of cataract.

  11. Endophthalmitis Following Pediatric Cataract Surgery: An International Pediatric Ophthalmology and Strabismus Council Global Perspective.

    Science.gov (United States)

    Gharaibeh, Almutez M; Mezer, Eedy; Ospina, Luis H; Wygnanski-Jaffe, Tamara

    2018-01-01

    To compile international data on the risk factors, diagnosis, and treatment of endophthalmitis following pediatric cataract surgery. An e-mail containing a link to an online survey was sent to all members of the American Association for Pediatric Ophthalmology and Strabismus. The questionnaire examined the incidence, risk factors, treatment, outcomes, and prophylaxis of endophthalmitis following pediatric cataract surgery around the world. Two hundred thirty-seven ophthalmologists answered the questionnaire. Eight ophthalmologists (3.4%) encountered 22 cases of endophthalmitis following pediatric cataract surgery during their practice. Most patients with endophthalmitis following pediatric cataract surgery were 2 to 4 years of age (36.4%). An intraocular lens was implanted in 59.1% of cases, most of which were acrylic intraocular lenses (53.8%). The main presenting symptoms were photophobia (50%) and pain (40.9%). The most common signs were conjunctival injection (36.4%) and hypopyon (31.8%). The final visual acuity was counting fingers or worse in 86% of cases. The most common cultured organism was Staphylococcus aureus (31.8%). The most common management of endophthalmitis following pediatric cataract surgery was a combination of intravitreal, systemic, and topical antibiotics (36.4%). Most ophthalmologists (68.2%) administered prophylactic intracameral antibiotic treatment during surgery and 50% used vancomycin. Endophthalmitis following pediatric cataract surgery is an uncommon, multifactorial complication with poor visual prognosis. Efforts directed at minimizing its risk, such as treating potential predisposing systemic conditions, improving sterilization techniques, optimizing operative conditions to reduce complications and surgery duration, and using subconjunctival and intracameral antibiotics, decrease its incidence. Early postoperative evaluation, subsequent follow-up visits, and keeping a high index of suspicion should facilitate the recognition of

  12. Advanced Cataracts and Pseudotumor Cerebri as the First Presentations of Hypoparathyroidism

    Directory of Open Access Journals (Sweden)

    Mehrdad Mohammadpour

    2013-10-01

    Full Text Available Purpose: To report a rare case of a patient with hypoparathyroidism presenting with bilateral disc swelling and near mature cataract as her first clinical manifestationCase report: A 23-year-old woman presented with complaint of worsening vision since one year ago and a history of refractory seizures and headache for several years, being under treatment with Lamotrigine 50 mg/daily. Slit-lamp examination revealed significant cataracts on both sides. Red reflex was dull in the right eye and absent in the left side. The intraocular pressure (IOP measurement was normal in both eyes (16 mmHg. Her fundus examination revealed disc swelling in her right eye and hazy media that obscured fundus examination due to dense cataract in the left eye. The combination of bilateral disc swelling and dense cataracts raised suspicion to hypoparathyroidism. Subsequently, neuroimaging and intracranial pressure (ICP monitoring was requested along with neuro-ophthalmalogy consultation. The diagnosis was Psedotumor Cerebri. Due to increased ICP, she underwent multiple lumber punctures. Computed tomography (CT scan showed abnormal signal density in basal ganglia suggestive for presence of calcium depositions, making the diagnosis of hypoparathyroidism more probable. Ensuing laboratory result made the definite diagnosis of hypoparathyroidism. Meanwhile the cataract progressed and the visual acuity (VA decreased to HM in her both eyes. She underwent cataract extraction and PCIOL implantation. Papilledema resolved and the vision restored to 20/20.Conclusion: Ocular complaints happens very rare in the course of hypoparathyroidism but still it seems rational that this occasionally fatal condition be ruled out by hormonal evaluation for cases of unexplained cataracts, particularly if it is accompanied by disc swelling.

  13. Age-Related Cataract, Cataract Surgery and Subsequent Mortality: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Song, E; Sun, Hongpeng; Xu, Yong; Ma, Yana; Zhu, Hong; Pan, Chen-Wei

    2014-01-01

    Purpose Changes in lens may reflect the status of systemic health of human beings but the supporting evidences are not well summarized yet. We aimed to determine the relationship of age-related cataract, cataract surgery and long-term mortality by pooling the results of published population-based studies. Methods We searched PubMed and Embase from their inception till March, 2014 for population-based studies reporting the associations of any subtypes of age-related cataract, cataract surgery with all-cause mortality. We pooled the effect estimates (hazards ratios [HRs]) under a random effects model. Results Totally, we identified 10 unique population-based studies including 39,659 individuals at baseline reporting the associations of any subtypes of cataract with all-cause mortality from 6 countries. The presence of any cataract including cataract surgery was significantly associated with a higher risk of death (pooled HR: 1.43, 95% CI, 1.21, 2.02; Pcataract were at higher risks of mortality (pooled HR: 1.55, 95% CI, 1.17, 2.05; P = 0.002; I2 = 89.2%). In the meta-analysis of 8 study findings, cortical cataract was associated with higher risks of mortality (pooled HR: 1.26, 95% CI, 1.12, 1.42; Pcataract was associated with higher risks of mortality (pooled HR: 1.37, 95% CI, 1.04, 1.80; P = 0.03; I2 = 67.3%). The association between cataract surgery and mortality was marginally non-significant by pooling 8 study findings (pooled HR: 1.27, 95% CI, 0.97, 1.66; P = 0.08; I2 = 76.6%). Conclusions All subtypes of age-related cataract were associated with an increased mortality with nuclear cataract having the strongest association among the 3 cataract subtypes. However, cataract surgery was not significantly related to mortality. These findings indicated that changes in lens may serve as markers for ageing and systemic health in general population. PMID:25369040

  14. Using qualitative methods to understand the determinants of patients' willingness to pay for cataract surgery: a study in Tanzania.

    Science.gov (United States)

    Geneau, Robert; Massae, Patrick; Courtright, Paul; Lewallen, Susan

    2008-02-01

    Cataract is the leading cause of avoidable blindness in Africa. There are various documented barriers to the uptake of cataract surgery, cost being one of them. There is, however, little evidence regarding patients' willingness to pay (WTP) for cataract surgery in Africa and the best way to measure it. We conducted a grounded theory study in order to understand better cataract patients' WTP for surgery in Tanzania. A total of 47 cataract patients from three regions of Tanzania were interviewed. The interviews were tape-recorded and transcribed verbatim. The coding process involved identifying emerging themes and categories and their interconnection. Our study reveals that the main factors behind patients' WTP for cataract surgery are (1) the level of perceived need for sight and cataract surgery; (2) the decision-making processes at the family level and (3) the characteristics of local eye care programs. Our study shows that WTP concerns not only the patients but also their relatives. For most patients and families, the amount of $20-$30 is deemed reasonable for a sight-restoring procedure. It does not appear realistic for eye care program managers to charge the real cost of cataract surgery at present (about US $70-in Kilimanjaro). However, eye care programs can influence WTP for cataract surgery by providing quality services and by offering adequate counseling about the procedure. The qualitative findings enriched the interpretation of a previously reported quantitative survey and yield implications for both researchers and decision-makers using or relying on WTP methodologies in developing countries.

  15. [The specific features of the development of metabolic and regenerative processes under the action of low-intensity electromagnetic radiation in radiation exposure conditions (an experimental study)].

    Science.gov (United States)

    Korolev, Yu N; Mihajlik, L V; Nikulina, L A; Geniatulina, M S

    2017-01-01

    The experiments on male white rats with the use of biochemical, photo-optical, and electron-microscopic techniques have demonstrated that the use of low-intensity electromagnetic radiation of ultrahigh frequency (EMR UHF) and low-intensity low-frequency magnetic field (MF) during the post-irradiation period (within 21 days after exposure to radiation) enhanced the metabolic and regenerative processes in the testes and liver. It was shown that the application of MF largely intensified the antioxidant activity whereas EMR UHF preferentially stimulated the biosynthetic processes as well as the processes of cellular and intracellular regeneration.

  16. Experimental system for in-situ measurement of temperature rise in animal tissue under exposure to acoustic radiation force impulse.

    Science.gov (United States)

    Nitta, Naotaka; Ishiguro, Yasunao; Sasanuma, Hideki; Taniguchi, Nobuyuki; Akiyama, Iwaki

    2015-01-01

    Acoustic radiation force impulse (ARFI) has recently been used for tissue elasticity measurement and imaging. On the other hand, it is predicted that a rise in temperature occurs. In-situ measurement of temperature rise in animal experiments is important, yet measurement using thermocouples has some problems such as position mismatch of the temperature measuring junction of the thermocouple and the focal point of ultrasound. Therefore, an in-situ measurement system for solving the above problems was developed in this study. The developed system is composed mainly of an ultrasound irradiation unit including a custom-made focused transducer with a through hole for inserting a thin-wire thermocouple, and a temperature measurement unit including the thermocouple. The feasibility of the developed system was evaluated by means of experiments using a tissue-mimicking material (TMM), a TMM containing a bone model or a chicken bone, and an extracted porcine liver. The similarity between the experimental results and the results of simulation using a finite element method (FEM) implied the reasonableness of in-situ temperature rise measured by the developed system. The developed system will become a useful tool for measuring in-situ temperature rise in animal experiments and obtaining findings with respect to the relationship between ultrasound irradiation conditions and in-situ temperature rise.

  17. Treatment of Experimental Acute Radiation Disease in Mice with Probiotics, Quinolones, and General Gnotobiological Isolation

    National Research Council Canada - National Science Library

    Korschunov, V

    1998-01-01

    ...) on intestinal microflora, translocation, and mortality was studied in mice treated with 7.0 Gy radiation. Lactobacilli and bifidobacteria, selected by in vitro and in vivo methods, increased survival parameters of the mice...

  18. Role of calcium in selenium cataract.

    Science.gov (United States)

    Shearer, T R; David, L L

    The purpose of this research was to test the role of certain minerals in the formation of cataract caused by an overdose of selenium. Several pieces of information indicated that lenticular calcium may play an important role in selenite cataractogenesis: 1) Lens calcium concentrations in selenite treated rats were increased more than 5-fold, and the increase in lens calcium was localized in the nucleus. 2) Lens calcium concentrations were elevated at least one full day before actual formation of nuclear cataract, but serum calcium levels were not changed. 3) In older rats not susceptible to selenite cataract, lens calcium was not significantly increased. 4) No evidence was found for a generalized disruption in lens permeability, since no major changes in lens water, sodium, and potassium levels were observed, and 5) when levels of calcium observed in selenite cataract were added to solutions of soluble proteins from rat lenses, light scattering was increased. Selenium-overdose cataracts may provide an important model for studies on the role of calcium in cataractogenesis.

  19. Achieving target refraction after cataract surgery.

    Science.gov (United States)

    Simon, Shira S; Chee, Yewlin E; Haddadin, Ramez I; Veldman, Peter B; Borboli-Gerogiannis, Sheila; Brauner, Stacey C; Chang, Kenneth K; Chen, Sherleen H; Gardiner, Matthew F; Greenstein, Scott H; Kloek, Carolyn E; Chen, Teresa C

    2014-02-01

    To evaluate the difference between target and actual refraction after phacoemulsification and intraocular lens implantation at an academic teaching institution's Comprehensive Ophthalmology Service. Retrospective study. We examined 1275 eye surgeries for this study. All consecutive cataract surgeries were included if they were performed by an attending or resident surgeon from January through December 2010. Postoperative refractions were compared with preoperative target refractions. Patients were excluded if they did not have a preoperative target refraction documented or if they did not have a recorded postoperative manifest refraction within 90 days. The main outcome measure was percentage of cases achieving a postoperative spherical equivalent ± 1.0 diopter (D) of target spherical equivalent. We performed 1368 cataract surgeries from January through December of 2010. Of these, 1275 (93%) had sufficient information for analysis. Of the included cases, 94% (1196 of 1275) achieved ± 1.0 D of target refraction by 90 days after cataract surgery. This paper establishes a new benchmark for a teaching hospital, where 94% of patients achieved within 1.0 D of target refraction after cataract surgery. The refractive outcomes after cataract surgery at this academic teaching institution were higher than average international benchmarks. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  20. Experimental proposal Test of radiation protection instrumentation in HiRadMat

    OpenAIRE

    Charitonidis, Nikolaos; Silari, Marco; Manessi, Paolo Giacomo

    2012-01-01

    The knowledge of the response of radiation protection detectors in pulsed fields is very important, since this is a typical condition often encountered with stray radiation fields around particle accelerators at CERN and elsewhere. This document presents a proposal for testing a prototype detector and commercial instrumentation in use with the RAMSES monitoring system, due to the unique conditions that can be found in the HiRadMat facility. These tests can be extended to include instrumentati...

  1. Surgical options for correction of refractive error following cataract surgery

    OpenAIRE

    Abdelghany, Ahmed A.; Alio, Jorge L.

    2014-01-01

    Summary Refractive errors are frequently found following cataract surgery and refractive lens exchange. Accurate biometric analysis, selection and calculation of the adequate intraocular lens (IOL) and modern techniques for cataract surgery all contribute to achieving the goal of cataract surgery as a refractive procedure with no refractive error. However, in spite of all these advances, residual refractive error still occasionally occurs after cataract surgery and laser in situ keratomileusi...

  2. Experimental Characterization of a Composite Morphing Radiator Prototype in a Relevant Thermal Environment

    Science.gov (United States)

    Bertagne, Christopher L.; Chong, Jorge B.; Whitcomb, John D.; Hartl, Darren J.; Erickson, Lisa R.

    2017-01-01

    For future long duration space missions, crewed vehicles will require advanced thermal control systems to maintain a desired internal environment temperature in spite of a large range of internal and external heat loads. Current radiators are only able to achieve turndown ratios (i.e. the ratio between the radiator's maximum and minimum heat rejection rates) of approximately 3:1. Upcoming missions will require radiators capable of 12:1 turndown ratios. A radiator with the ability to alter shape could significantly increase turndown capacity. Shape memory alloys (SMAs) offer promising qualities for this endeavor, namely their temperature-dependent phase change and capacity for work. In 2015, the first ever morphing radiator prototype was constructed in which SMA actuators passively altered the radiator shape in response to a thermal load. This work describes a follow-on endeavor to demonstrate a similar concept using highly thermally conductive composite materials. Numerous versions of this new concept were tested in a thermal vacuum environment and successfully demonstrated morphing behavior and variable heat rejection, achieving a turndown ratio of 4.84:1. A summary of these thermal experiments and their results are provided herein.

  3. The Radiation Problem and Its Solution from a Health Communication Perspective

    Science.gov (United States)

    2016-01-01

    This paper observes both foreign and national discussions on preexisting radiation communication and attempts to find out what it takes to ensure that discussion concerning radiation leads to participation of and trust-building with members of society while considering cultural aspects. When analyzing Korean studies on health risk communication concerning radiation which utilize the frame of foreign literature, Korean studies can be categorized into one of the following themes: different risk perceptions between experts and the general public, discussion on the effects of the framing of radiation messages and media coverage, and research discussing the social implications of the dangers of radiation and the need for effective communication. These study results can be better explained when integrated with Korean social cultural dimensions. The “boiling pot effect” towards risk issues, egalitarian perceptions, escalation of ideological opposition and biased reasoning, and so on are especially major influences. Communication addressing radiological risks must foremost be open and able to mitigate distrust, must give the general public a chance to judge for themselves to prevent stigmatization, and, through the use of media and public education, must make efforts to prevent the proliferation of needless anxiety. Using literature research, this paper discusses possible ways to improve the effect of future health risk communication concerning radiation. PMID:26908994

  4. The Radiation Problem and Its Solution from a Health Communication Perspective.

    Science.gov (United States)

    Kim, Yungwook

    2016-02-01

    This paper observes both foreign and national discussions on preexisting radiation communication and attempts to find out what it takes to ensure that discussion concerning radiation leads to participation of and trust-building with members of society while considering cultural aspects. When analyzing Korean studies on health risk communication concerning radiation which utilize the frame of foreign literature, Korean studies can be categorized into one of the following themes: different risk perceptions between experts and the general public, discussion on the effects of the framing of radiation messages and media coverage, and research discussing the social implications of the dangers of radiation and the need for effective communication. These study results can be better explained when integrated with Korean social cultural dimensions. The "boiling pot effect" towards risk issues, egalitarian perceptions, escalation of ideological opposition and biased reasoning, and so on are especially major influences. Communication addressing radiological risks must foremost be open and able to mitigate distrust, must give the general public a chance to judge for themselves to prevent stigmatization, and, through the use of media and public education, must make efforts to prevent the proliferation of needless anxiety. Using literature research, this paper discusses possible ways to improve the effect of future health risk communication concerning radiation.

  5. An Experimental Study on the Radiation Noise Characteristics of a Centrifugal Pump with Various Working Conditions

    Directory of Open Access Journals (Sweden)

    Chang Guo

    2017-12-01

    Full Text Available To investigate the radiation noise characteristics of a centrifugal pump under various working conditions, a noise measurement system is established; afterwards, the distribution of different points and intervals, as well as the overall level of noise, are studied. The total sound pressure level distribution for different points manifests the dipole and asymmetric directivity characteristics. Additionally, the acoustic energy is introduced to compare the noise of different intervals to reveal the asymmetric characteristics, and it is found that variation in working conditions has little impact on the acoustic energy distribution, and the ratio of the acoustic energy in the direction facing the tongue, as well as that in the direction against the tongue, to total acoustic energy fluctuate around 0.410 and 0.160, respectively, under various working conditions. Also, the A-weighted average sound pressure level (LpA is applied to describe the overall level of noise, and LpA increases gradually with the growth of rotational speed, but the growth slope decreases. While in the operation of throttling regulation, LpA shows the trend that first increases, then remains stable, and increases again with the growth of flow rate. This study could provide guidance for optimizing the operating conditions and noise control of centrifugal pumps.

  6. [Experimental justification of possible mechanisms of action of low intensity electromagnetic radiation (EMR) on animals' behavior].

    Science.gov (United States)

    Pavlov, L N; Dubrovik, B V; Zhavoronkov, l P; Glushakova, V S

    2012-01-01

    Effects of EMR on the behavior of Wistar rats (196 males, 180-240 g of mass) under the conflict of opposed motivations: strong positive, drinking, motivation, and strong negative, pain, motivation were studied. The animals were exposed to low intensity EMR (40 microW/cm2) produced by two independent sources, 475 MHz (Albatross) with two orthogonal E vectors, and synchronization of rhythm modulation in the range of electroencephalography (EEG) frequency. The effect on behavior was observed during 10 min: 1) following the 5-minute exposure to EMR and 2) during the 10-minute exposure. Low intensity EMR of the above mentioned parameters and pulse modulation of 4, 8, 10 and 13 Hz was found to inhibit development of phobia to pain, increase the number of punishable contacts. It testifies to the existence of a weak anxiolytic effect which is similar to the effect of tranquilizers. If animals were exposed to EMR following administration of phenazepam, the radiation was shown to produce potentiation of the anxiolytic effect ofphenazepam. Effect of phenazepam is associated with activation ofbenzdiazipine receptors in the structure ofGABA-ergic receptor complex, which regulates neural membrane chloride channel conductance. We can suggest that anxiolytic and neurodepressive effects of EMR are realized to some extent at the level of ionophore and regulatory receptor complexes.

  7. Spectacle use after routine cataract surgery.

    Science.gov (United States)

    Wilkins, M R; Allan, B; Rubin, G

    2009-10-01

    To measure spectacle dependence following bilateral monofocal intraocular lens (IOL) implantation and assess how it is predicted by postoperative refraction. 300 cataract patients had bilateral phacoemulsification surgery with monofocal IOL implantation. A spherical equivalent of 0 to -0.5 D was targeted. Three months after surgery, patients answered a questionnaire and had a spectacle refraction. Refractions were converted into vector notation. Logistic regression was used to evaluate whether spectacle dependence for near and distance was related to overall refractive error, spherical error, signed spherical error and astigmatic error. 169 patients attended for assessment. 38 wore distance glasses, and 160 wore reading glasses either some or all of the time. The mean right spherical equivalent was -0.03 D, and the mean right cylinder was -0.64 D. Left outcomes were similar. Patients were 34 times more likely to always use distance glasses per dioptre of astigmatic error in the better eye (p0.15). Similar effects were seen for both the better and worse eyes. Near-spectacle use was not dependent on astigmatic error (odds ratio = 0.22, p>0.12). It was only related to the signed spherical error in the worse eye with hypermetropic patients 6.74 times more likely to always wear spectacles per dioptre of positive spherical error (pspectacle dependence, whereas spherical ammetropia in the range of +/-1.0 D does not. Hypermetropia in the worse eye, but not astigmatism, predicts reading-spectacle dependence.

  8. Age and Smoking Related Changes in Metal Ion Levels in Human Lens: Implications for Cataract Formation.

    Science.gov (United States)

    Langford-Smith, Alex; Tilakaratna, Viranga; Lythgoe, Paul R; Clark, Simon J; Bishop, Paul N; Day, Anthony J

    2016-01-01

    Age-related cataract formation is the primary cause of blindness worldwide and although treatable by surgical removal of the lens the majority of sufferers have neither the finances nor access to the medical facilities required. Therefore, a better understanding of the pathogenesis of cataract may identify new therapeutic targets to prevent or slow its progression. Cataract incidence is strongly correlated with age and cigarette smoking, factors that are often associated with accumulation of metal ions in other tissues. Therefore this study evaluated the age-related changes in 14 metal ions in 32 post mortem human lenses without known cataract from donors of 11 to 82 years of age by inductively coupled plasma mass spectrometry; smoking-related changes in 10 smokers verses 14 non-smokers were also analysed. A significant age-related increase in selenium and decrease in copper ions was observed for the first time in the lens tissue, where cadmium ion levels were also increased as has been seen previously. Aluminium and vanadium ions were found to be increased in smokers compared to non-smokers (an analysis that has only been carried out before in lenses with cataract). These changes in metal ions, i.e. that occur as a consequence of normal ageing and of smoking, could contribute to cataract formation via induction of oxidative stress pathways, modulation of extracellular matrix structure/function and cellular toxicity. Thus, this study has identified novel changes in metal ions in human lens that could potentially drive the pathology of cataract formation.

  9. Ultrasonographic findings in patients examined in cataract detection-andtreatment campaigns: a retrospective study

    Directory of Open Access Journals (Sweden)

    Marcio Henrique Mendes

    2009-01-01

    Full Text Available INTRODUCTION: A cataract is defined as an opacity of any portion of the lens, regardless of visual acuity. In some advanced cases of cataracts, in which good fundus visualization is not possible, an ultrasound examination provides better assessment of the posterior segment of the globe. OBJECTIVES: This study aims to evaluate the ultrasonographic records of patients with advanced cataracts who were examined during cataract campaigns. METHODS: The ultrasonographic findings obtained from 215 patients examined in cataract campaigns conducted by the Hospital das Clínicas Department of Ophthalmology of the Faculdade de Medicina da Universidade de São Paulo between the years of 2005 and 2007 were evaluated, and the utility of this exam in changing the treatment procedures was studied. RESULTS: A total of 289 eyes from 215 patients were examined. Of the eyes examined, 77.5% presented with findings in the vitreous cavity and the posterior pole. A posterior vitreous detachment with no other complications was observed in 47.4% of the eyes. The remaining 30.1% presented with eye diseases that could result in a reduced visual function after surgery. The most frequent eye diseases observed were diffuse vitreous opacity (12.1% of the eyes and detachment of the retina (9.3% of the eyes. DISCUSSION: In many cases, the ultrasonographic evaluation of the posterior segment revealed significant anomalies that changed the original treatment plan or contra-indicated surgery. At the very least, the evaluation was useful for patient counseling. CONCLUSION: The ultrasonographic examination revealed and differentiated between eyes with cataracts and eyes with ocular abnormalities other than cataracts as the cause of poor vision, thereby indicating the importance of its use during ocular evaluation.

  10. Age and Smoking Related Changes in Metal Ion Levels in Human Lens: Implications for Cataract Formation.

    Directory of Open Access Journals (Sweden)

    Alex Langford-Smith

    Full Text Available Age-related cataract formation is the primary cause of blindness worldwide and although treatable by surgical removal of the lens the majority of sufferers have neither the finances nor access to the medical facilities required. Therefore, a better understanding of the pathogenesis of cataract may identify new therapeutic targets to prevent or slow its progression. Cataract incidence is strongly correlated with age and cigarette smoking, factors that are often associated with accumulation of metal ions in other tissues. Therefore this study evaluated the age-related changes in 14 metal ions in 32 post mortem human lenses without known cataract from donors of 11 to 82 years of age by inductively coupled plasma mass spectrometry; smoking-related changes in 10 smokers verses 14 non-smokers were also analysed. A significant age-related increase in selenium and decrease in copper ions was observed for the first time in the lens tissue, where cadmium ion levels were also increased as has been seen previously. Aluminium and vanadium ions were found to be increased in smokers compared to non-smokers (an analysis that has only been carried out before in lenses with cataract. These changes in metal ions, i.e. that occur as a consequence of normal ageing and of smoking, could contribute to cataract formation via induction of oxidative stress pathways, modulation of extracellular matrix structure/function and cellular toxicity. Thus, this study has identified novel changes in metal ions in human lens that could potentially drive the pathology of cataract formation.

  11. The Effect of Trabeculectomy on Cataract Formation or Progression

    Directory of Open Access Journals (Sweden)

    Zhale Rajavi

    2009-04-01

    progression without reduced VA. CONCLUSION: Cataracts seem to progress following trabeculectomy; therefore it might be advisable to perform a combined procedure in older patients with moderate lens opacities.

  12. Outcome of Cataract Surgery in Lafia | Adenuga | Journal of ...

    African Journals Online (AJOL)

    Ninety six eyes had extracapsular cataract extraction with intraocular lens implantation and 130 eyes had manual small incision cataract surgery with intraocular lens implantation. Postoperative best corrected visual acuity of 6/18 or better was achieved in 49% of all eyes, in 46% of eyes that had extracapsular cataract ...

  13. Prognosis of senile cataract extraction with increasing age | Idu ...

    African Journals Online (AJOL)

    In order to determine the prognosis of senile cataract extraction with increasing age, a case series of 240 patients without ocular or systemic comorbidity aged 51 to 80 years who underwent intracapsular cataract extraction (ICCE), and extracapsular cataract extraction (ECCE), between January 1991 andDecembers 2000 ...

  14. Monitoring Cataract Surgical Outcome in a Public Hospital in Orlu ...

    African Journals Online (AJOL)

    Objective: To determine the proportion and causes of poor visual outcome of cataract operations done in a public hospital in southeast Nigeria and propose actions to improve the cataract surgical outcome. Method: A prospective observational analysis of the initial hundred cases of cataract operations done in Imo State ...

  15. 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.

  16. Cataract surgical uptake among older adults in Ghana | Ackuaku ...

    African Journals Online (AJOL)

    Objectives: In sub-Saharan Africa, cataract surgical services are highly inadequate and surgical uptake for cataract is low. This paper describes cataract surgical uptake among older adults in Ghana. Methods: This work was based on World Health Organization's multi-country Study on global Ageing and adult health ...

  17. Laser fluorescent method for differential diagnostics of cataract

    Science.gov (United States)

    Salmin, Vladimir V.; Provorov, Alexander S.; Lazarenko, Victor I.; Salmina, Alla B.; Oskirko, Svetlana A.; Fokina, Darya S.; Vladimirova, Ekaterina S.

    2007-06-01

    Laser fluorescent analysis has been used for assessing the spectra of normal and nuclear cataract lens fluorescence in vivo. Spectral criterion (index of opacity) was developed for objective differentiation of cataract's stage. Contribution of ascorbic acid into spectrum of cataract lens fluorescence was analyzed.

  18. Parinaud's oculoglandular syndrome and possibly causing cortical cataract

    Directory of Open Access Journals (Sweden)

    Mariana Heid Rocha Hemerly

    2014-06-01

    Full Text Available According to the World Health Organization, cataract is the leading cause of blindness and visual impairment throughout the world. However, the etiology of cataracts often remains unknown. This report describes the development of cortical cataract in a patient after Parinaud's oculoglandular syndrome caused by the fungus Sporothrix schenckii.

  19. Visual Outcome after Small Incision Cataract Surgery in South ...

    African Journals Online (AJOL)

    user

    –75% of people who have had cataract surgery have a presenting visual acuity of worse than ..... care after cataract surgery in rural China. Archives of. Ophthalmology 2007; 11:125-127. 17 Lewallen S, Courtright P. Gender and use of cataract ...

  20. The Paediatric Cataract Register (PECARE): an overview of operated childhood cataract in Sweden and Denmark.

    Science.gov (United States)

    Magnusson, Gunilla; Haargaard, Birgitte; Basit, Saima; Lundvall, Anna; Nyström, Alf; Rosensvärd, Annika; Tornqvist, Kristina

    2018-02-01

    To report basic epidemiological data concerning surgically treated childhood cataract in Sweden and Denmark. Data were derived from the Paediatric Cataract Register (PECARE), a binational, web-based surgical register representing Sweden and Denmark. All children operated before 8 years of age between 1 January 2007 and 31 December 2013 were included. Age-specific prevalence per 100 000 population was calculated. A total 574 operations in 213 boys (51.7%) and 199 girls (48.3%), altogether 412 children, were registered, the vast majority (n = 395/412; 95.9%) being individuals with congenital/infantile cataract. Of these 412, a total of 294 (147 boys and 147 girls) were Swedish and 118 (66 boys and 52 girls) were Danish. The age-specific prevalence of operated cataract in Sweden was 31/100 000 and in Denmark 28/100 000. In 454 of 574 eyes (79.1%), the cataract was dense. Altogether, 266 of 574 (46.3%) were operated during the first year of life, 193 during the first 12 weeks representing 33.6% of all operations. A primary intraocular lens (IOL) implantation was done in altogether 411 of 574 eyes (71,6%). In total, 210 unilateral cataract operations (210/574; 36.6%) were performed. Persistent fetal vasculature (PFV) was present in 64 of 193 (33.1%) of those with a congenital unilateral cataract. In 84 individuals (84/395; 21.3%) with congenital or infantile cataract, a coexisting disorder was found. The age-specific binational prevalence of operated congenital/infantile cataract in Sweden and Denmark is 30/100 000. About half of the operations are performed within the first year of life, one-third within the first 3 months. In our study population, a primary IOL was implanted in the majority of cases. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.