22 research outputs found

    VISJET-a computer ocean outfall modelling system

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    Sewage and industrial effluents from coastal cities are often discharged into the adjacent sea after some land-based treatment. In modern design, the wastewater is often discharged in buoyant jet groups from risers mounted on a submarine outfall on the seabed to achieve rapid mixing of effluents with tidal flow. A mathematical model for buoyant jets in currents based on the Lagrangian models, called JETLAG, was developed. The paper presents a system called VISJET, for visualizing the ocean sewage discharge system based on the JETLAG model. We discuss the features of VISJET system and show how computer visualization can be used to help with the design of an ocean sewage discharge system.published_or_final_versio

    Current approaches to the management of acute primary angle closure

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    PURPOSE OF REVIEW: Recent advances in the management of acute primary angle closure include argon laser peripheral iridoplasty, immediate anterior chamber paracentesis, and cataract or lens extraction by phacoemulsification. This review summarizes current thoughts on the role of these treatment modalities. RECENT FINDINGS: Argon laser peripheral iridoplasty has been shown to be superior to treatments using combined topical and systemic medications in controlling intraocular pressure in acute primary angle closure. Immediate paracentesis has been shown to be very effective for aborting the condition. This is a good alternative for suitable cases and especially in settings in which laser equipment is not readily available. Cataract or lens extraction by phacoemulsification appears to be promising in preventing progression to chronic angle closure glaucoma after acute primary angle closure. SUMMARY: Surgical trials are underway to examine the role of cataract/lens extraction in post-acute primary angle closure. This technique has the potential to prevent recurrence of the condition and progression to chronic angle closure glaucoma. With existing and upcoming new data on managing acute primary angle closure, it is hopeful that a more optimal treatment algorithm will be established soon. © 2007 Lippincott Williams & Wilkins, Inc.link_to_subscribed_fulltex

    VISJET - a computer ocean outfall modelling system

    No full text
    Sewage and industrial effluents from coastal cities are often discharged into the adjacent sea after some land-based treatment. In modern design, the wastewater is often discharged in buoyant jet groups from risers mounted on a submarine outfall on the seabed to achieve rapid mixing of effluents with tidal flow. A mathematical model for buoyant jets in currents based on the Lagrangian models, called JETLAG, was developed. This paper presents a system, called VISJET, for visualizing the ocean sewage discharge system based on the JETLAG model. We will discuss the features of VISJET system and show how computer visualization can be used to help with the design of an ocean sewage discharge system.link_to_subscribed_fulltex

    Extent and predictors of microbial hand contamination in a tertiary care ophthalmic outpatient practice

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    PURPOSE. To measure the extent of microbial hand contamination among ophthalmologists during routine clinic practice and examine its association with hand cleansing practices and beliefs, glove use, and patient load. METHODS. This was a single-masked analysis of resident and transient flora of ophthalmologists before and after patient examination and after handwashing by agar imprints of the dominant hand. Standardized questionnaires were used to collect information concerning subjects' hand cleansing practices and patient load. RESULTS. Of the 108 cultures, 107 (99.1%) were culture positive, yielding 15 separate organisms. Gram-negative bacilli were the most common transient flora, followed by Gram-positive cocci and fungi. Thirty-five (97.2%) ophthalmologists were culture positive for at least one resident and 8 (22.2%) ophthalmologists were culture positive for at least one transient organism, before patient contact. Regression models showed alcohol-based hand rub use, transient and resident floral load before patient contact, and patient load collectively accounted for 58.7% of the variance in resident floral load after patient contact. Use of alcohol-based hand rubs was associated with a mean resident floral reduction of 324.4 CFUs (95% confidence interval [CI] = 185.4 to 463.5; P < 0.01) and 31.6 CFUs (95% CI = 1.2 to 62.0; P < 0.05) after patient contact and handwashing, respectively. Handwashing with chlorhexidine was a significant predictor for transient floral load after handwashing (unstandardized β = -17.2; 95% CI = -10.2 to -24.2; P < 0.01). CONCLUSIONS. The extent of contamination with pathogenic organisms after contact with eye outpatients, who have traditionally been perceived as relatively "clean," was of concern. Previously identified risk factors for hand contamination in inpatient settings, such as patient load, only explained a small proportion of variance in microbial load in the ophthalmic outpatient setting. Copyright © Association for Research in Vision and Ophthalmology.link_to_subscribed_fulltex

    Unusual presentation of angle-closure glaucoma treated by phacoemulsification

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    Normal Tension Glaucoma

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    Normal tension glaucoma (NTG), as described by von Graefe in 1857, is a clinical condition in which the optic nerve is pathologically excavated and the visual field (VF) is characteristically disturbed, although the intraocular pressure (IOP) is within the statistically normal range. It may be defined using the criteria from the Collaborative NTG Study (CNTGS). Various studies revealed different prevalence for NTG. Some of them are presented in this chapter. This chapter also provides a comprehensive discussion on causes of NTG including pathophysiology and optic disc appearance, natural course of NTG, and the diagnosis, management and follow-up of NTG patients

    Effects of phacoemulsification versus combined phaco-trabeculectomy on drainage angle status in primary angle closure glaucoma (PACG)

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    PURPOSE: To document anatomic effects of phacoemulsification versus combined phaco-trabeculectomy on drainage angle in primary angle closure glaucoma (PACG). METHODS: Indentation gonioscopy and ultrasound biomicroscopy were performed preoperatively, and then at 1 year after phacoemulsification alone or combined phaco-trabeculectomy in PACG patients. RESULTS: Seventy-two PACG eyes of 72 patients were included in this study. Thirty-eight eyes were randomized into receiving phacoemulsification alone, whereas 34 eyes had combined phaco-trabeculectomy. The mean extent of synechial angle closure was significantly reduced from 266.4° to 198.9° (P<0.001) by phacoemulsification alone, and from 266.0° to 227.2° (P=0.03) by combined surgery. The mean angle opening distance (AOD 500) measured by ultrasound biomicroscopy was significantly increased from 208.0 to 468.0 μm (P<0.001) by phacoemulsification, and from 214.6 to 344.4 μm (P<0.001) by combined surgery. The mean trabecular-ciliary process distance was significantly increased from 824.6 to 1043.6 μm (P<0.001) by phacoemulsification, and from 800.9 to 951.5 μm (P=0.01) by combined surgery. The mean anterior chamber depth was significantly increased from 1798.6 to 3528.4 μm (P<0.001) by phacoemulsification alone, and from 1781.6 to 3297.8 μm (P<0.001) by combined surgery. Phacoemulsification alone resulted in significantly greater postoperative angle opening distance 500 (P<0.001) and anterior chamber depth (P<0.001) than phaco-trabeculectomy. CONCLUSIONS: Phacoemulsification alone resulted in greater opening of drainage angle and greater deepening of anterior chamber than combined phaco-trabeculectomy in PACG eyes. SYNOPSIS: Phacoemulsification alone resulted in greater opening of drainage angle and greater deepening of anterior chamber than combined phaco-trabeculectomy in PACG eyes. © 2010 Lippincott Williams & Wilkins, Inc.link_to_subscribed_fulltex

    Novel approach for anterior chamber angle analysis: Anterior Chamber Angle Detection with Edge Measurement and Identification Algorithm (ACADEMIA)

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    Objective: To describe a novel approach to measuring anterior chamber angle dimensions and configurations. Methods: Sixty-nine images were selected randomly from the ultrasound biomicroscopic image database to develop the algorithm. Thirty images were selected for further analyses. The value of each pixel of the 8-bit grayscale ultrasound biomicroscopic images was quantized into 0 (black) or 1 (white), and the edge points outlining the angle were detected and fitted with straight lines. The dimensions and profiles of anterior chamber angles were then measured. Results: The algorithm failed to identify the edge points correctly in 8 (11.6%) of 69 images because of strong background noise. Three basic types of angle configuration were identified based on the derived angle profiles: constant, increasing, and decreasing, which corresponded to flat, bowed forward, and bowed backward iris contours, respectively. The angle measurements demonstrated high correlation with trabecular-iris angle and angle opening distance 500 (calculated as the distance from the corneal endothelium to the anterior iris surface perpendicular to a line drawn at 500 μm from the scleral spur). The strongest association was found between the averaged angle derived from the angle profile and the angle opening distance 500 (r=0.91). Conclusion: The proposed algorithm has high correlations with angle opening distance and trabecular-iris angle with the added advantages of being fully automated, reproducible, and able to capture the characteristic angle configurations. However, good-quality ultrasound biomicroscopic images with high signal-to-noise ratio are required to identify the edge points correctly. ©2006 American Medical Association. All rights reserved.link_to_subscribed_fulltex
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