33 research outputs found

    Grain Surface Models and Data for Astrochemistry

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    AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions

    APPLICATION OF MODIFIED NEI VFQ-25 AFTER RETINAL DETACHMENT TO VISION-RELATED QUALITY OF LIFE.

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    We examined the postoperative visual recovery and quality of life after retinal detachment (RD) surgery. In addition to a baseline clinical examination, patients filled out the National Eye Institute Visual Functioning Questionnaire at three time points: preoperatively and 1 and 3 months postoperatively (M1 and M3, respectively). We analyzed the composite score and short-form scores (socioemotional scale [SFSES] and visual functioning scale [SFVFS]). One hundred ninety-four patients were enrolled in this study; 47 (26 macula-ON RD and 21 macula-OFF RD) returned all three questionnaires. The best corrected visual acuity was Snellen equivalent 20/25, 20/25, and 20/20 at the preoperative, M1, and M3 assessment, respectively. At M3, we found a positive correlation between SFSES and best corrected visual acuity measures among macula-OFF patients (P < 0.001, R2 = 0.58). A significant correlation with the best corrected visual acuity among macula-ON patients was observed only at M3 with the SFVFS score (P < 0.001, R2 = 0.41). The quality of life differs between ON and OFF RD in regard to the composite score and especially SFSES and SFVFS. We found a transient decrease in the quality of life at M1 for macula-ON patients, whereas the quality of life improved throughout follow-up among macula-OFF patients. These data may help improve the management of patients' expectations after RD surgery

    LUMINESCENCE AND FLUORESCENCE LINE NARROWING STUDIES OF CHROMIUM DOPED GLASS

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    The technique of fluorescence line narrowing is applied to the 2E - 4A2 transition on Cr3+ ions in ED-2 glass. The resultant sharp zero-phonon line is accompanied by a vibrational sideband which carries information about the range of vibrational modes of the glass. The homogeneous broadening of the zero-phonon line is measured as a function of temperature

    EVOLUTION AND PATTERNS OF CHOROIDAL THICKNESS CHANGES IN RHEGMATOGENOUS RETINAL DETACHMENT.

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    To evaluate the changes in choroidal thickness (CT) before and after a successful pars plana vitrectomy for rhegmatogenous retinal detachment (RD), and to compare the evolution of CT with respect to the extent of RD. Fifty-four patients were divided into three groups: peripheral macula-on RD (>3 mm from the fovea; 14 eyes); paracentral macula-on RD (fovea-sparing; ≤3 mm from the fovea; 14 eyes); and macula-off RD (involving the fovea; 26 eyes). Choroidal thickness was measured at 1 month (M1) and 3 months (M3) postoperatively, preoperatively in macula-on RDs, with enhanced depth imaging optical coherence tomography, from the nasal side (+2.5 mm) to the temporal side (-2.5 mm) of the fovea. In peripheral macula-on RD, the intereye difference in CTs showed thickening throughout follow-up (subfoveally: preoperatively = 19.6% ± 43.9%, M1 = 22.9% ± 27.5%, M3 = 18.2% ± 35.6%). In paracentral macula-on RD, the intereye difference in CTs showed a thinning throughout follow-up (subfoveally: preoperatively = -7.8% ± 21.9%, M1 =-5.5% ± 26.1%, M3 = -9.3% ± 19.4%), as well as in the macula-off RD (subfoveally: M1 = -14.1% ± 18.7%, M3 = -9.9% ± 15%). The extent of RD was related to the evolution of the CT before and after surgery. Further studies are necessary to clarify the relationship between the changes in CT and the effects of circulatory alterations, vitrectomy, and RD

    SOIN - MI Data Lab: Personalized Ophthalmology Through Collaborative Data Collection and Dynamic Patient Consent.

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    The Swiss Ophthalmic Image Network (SOIN) is part of the Swiss Personalized Health Network (SPHN). SOIN contains a collaborative, clinical research environment, MI Data Lab, which allows privacy-preserving, data-driven, research. Personalized care of chronic ocular disease, based on Machine Learning (ML) and medical imaging, can dramatically improve quality of life and reduce the burden on health and social care systems. MI Data Lab allows research partners to consolidate their data in a space where doctors and data scientists cooperate to design novel ML algorithms, on curated datasets. To date, we have created several algorithms to detect ocular biomarkers automatically, and applied such tools to 100k+ retinal images. MI Data Lab enables the development of predictive models, the extraction novel traits to be explored in terms of -omic associations, treatment outcome, and priors for disease progression

    Pseudophakic Retinal Detachment Surgery by 23 G Vitrectomy using Slit-Lamp and Non-Contact 90 D Lens.

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    Background: The purpose of this study is to report the anatomic and functional results of primary 23 G vitrectomy using slit-lamp and non-contact 90 D lens for the treatment of pseudophakic rhegmatogenous retinal detachment. Patients and Methods: Pseudophakic eyes were operated by 23 G vitrectomy using slit-lamp and non-contact 90 D lens, internal subretinal fluid drainage, cryopexy and internal gas tamponade. The preoperative and postoperative characteristics were analysed. Main outcome measures were anatomic success rates after initial surgical intervention and after reoperation for primary failures, visual outcome at the last follow-up visit, and complications. Results: 46 pseudophakic eyes were included in this retrospective study (October 2013- January 2014). In 40 cases, sulfur hexafluoride 23 % gastamponade was used, silicone oil in 6 cases (13 %). The retina was reattached successfully after a single surgery in 44 eyes (96 %). Recurrence of retinal detachment occurred in 2 eyes. Final anatomic reattachment was obtained in 100 % after a second operation. Silicone oil was removed in all eyes. Visual acuity improved significantly from logMAR 0 (IQR 0 - 0.9) to logMAR 0 (IQR 0 - 0.2) (p < 0.005). Conclusions: Primary 23 G vitrectomy using slit-lamp and non contact 90 D lens for the treatment of pseudophakic rhegmatogenous retinal detachment provides a high anatomic and functional success rate and is associated with few complications

    Primary rhegmatogenous retinal detachment: risk factors for macular involvement.

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    Rhegmatogenous retinal detachment (RD) has diagnostically been divided into macula-OFF or macula-ON. The aim of this study was to describe the demographics and primary outcome of patients with RD following surgery with respect to the macular status, and to determine risk factors for macular involvement. This prospective, observational, mono-centric cohort study was conducted at the Jules-Gonin Eye Hospital, from February 2015 until March 2017. The study included 194 eligible patients with primary RD. All patients underwent surgical treatment after baseline clinical examination. The dataset was analyzed using descriptive and analytic statistics. A total of 52.6% (102/194) of patients presented with macula-OFF RD. Mean age was 63.9 ± 12.0 vs. 59.7 ± 11.2 years in the OFF and ON group, respectively. There were 129 men (66.5%) and 65 (33.5%) women, and there were significantly more right eyes affected [right vs. left eyes 123 (63.4%) vs. 71 (36.6%), p = 0.000]. Significantly more myopes (<-3D) presented with a macula-ON RD (p = 0.04). There were more phakic patients in the cohort (55.7%), and phakic eyes were more likely to present with macula-ON RD (p = 0.01). Multivariate modeling showed that pseudophakic lens status and eyes with axial length less than 25 mm (p = 0.06) are independent predictive factors for macula-OFF RD (p = 0.02), whereas sex and laterality were not risk factors for macular involvement. Pseudophakic lens status and axial length < 25 mm are independent predictive factors for macula-OFF RD. While pseudophakic lens status is a recognized risk factor for RD, shorter axial length has not been previously identified as a risk factor for the macula-OFF RD
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