436 research outputs found

    Evaluation of the American Dream Demonstration: Final Evaluation Report

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    Evaluation of the American Dream Demonstration: Final Evaluation Repor

    The kinetics of the reaction of superoxide radical with Fe(III) complexes of EDTA, DETAPAC and HEDTA

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    AbstractTo gain an understanding of the mechanism by which the hydroxyl free radical can arise in superoxide generating systems and learn how different chelaters of iron can inhibit this reaction, a pulse radiolysis kinetic study of the reaction of O−2 with Fe(III)EDTA, Fe(III)HEDTA and Fe(III)DETAPAC (or DTPA) was undertaken. Superoxide reacts readily with Fe(III)EDTA and Fe(III)HEDTA with a pH-dependent second-order rate constant having values of 1.9 × 106 M−1.s−1 and 7.6 × 105 M−1.s−1 at pH 7, respectively. However, the rate constant for the reaction of O−2 with Fe(III)DETAPAC was found to be much slower, the upper limit for the rate constant being 104 M−1.s−1. These results in conjunction with spin-trapping experiments with Fe(II)EDTA, Fe(II)HEDTA, Fe(II)DETAPAC and H2O2 suggests that DETAPAC inhibits the formation of OH by slowing the reduction of Fe(III) to Fe(II) and not by inhibiting the Fenton reaction

    Depression & Work Function: Bridging the Gap Between Mental Health Care & the Workplace

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    Depression is rapidly emerging as both a public health and occupational health challenge. This document reviews many of the current clinical and workplace issues associated with this complex disorder and provides a framework for an integrated and comprehensive approach to managing depression in the workplace. In an effort to catalyze action, the report strives to maintain a practical perspective that will appeal to the many stakeholders who must collaborate to create a psychologically healthy workplace. This paper examines clinical and occupational best practices, recommends a systematic array of potential interventions, and identifies numerous resources to assist organizations to develop a customized response that meets their unique needs

    Serum dioxin concentrations and endometriosis: a cohort study in Seveso, Italy.

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    Dioxin, a ubiquitous contaminant of industrial combustion processes including medical waste incineration, has been implicated in the etiology of endometriosis in animals. We sought to determine whether dioxin exposure is associated with endometriosis in humans. We conducted a population-based historical cohort study 20 years after the 1976 factory explosion in Seveso, Italy, which resulted in the highest known population exposure to 2,3,7,8-tetrachlorodibenzo-(italic)p(/italic)-dioxin (TCDD). Participants were 601 female residents of the Seveso area who were (3/4) 30 years old in 1976 and had adequate stored sera. Endometriosis disease status was defined by pelvic surgery, current transvaginal ultrasound, pelvic examination, and interview (for history of infertility and pelvic pain). "Cases" were women who had surgically confirmed disease or an ultrasound consistent with endometriosis. "Nondiseased" women had surgery with no evidence of endometriosis or no signs or symptoms. Other women had uncertain status. To assess TCDD exposure, individual levels of TCDD were measured in stored sera collected soon after the accident. We identified 19 women with endometriosis and 277 nondiseased women. The relative risk ratios (RRRs) for women with serum TCDD levels of 20.1-100 ppt and >100 ppt were 1.2 [90% confidence interval (CI) = 0.3-4.5] and 2.1 (90% CI = 0.5-8.0), respectively, relative to women with TCDD levels (3/4) 20 ppt. Tests for trend using the above exposure categories and continuous log TCDD were nonsignificant. In conclusion, we report a doubled, nonsignificant risk for endometriosis among women with serum TCDD levels of 100 ppt or higher, but no clear dose response. Unavoidable disease misclassification in a population-based study may have led to an underestimate of the true risk of endometriosis

    Structure–activity relationships in hydroxy-2,3-diarylxanthone antioxidants. Fast kinetics spectroscopy as a tool to evaluate the potential for antioxidant activity in biological systems

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    A structure–activity relationship has been established for eight hydroxy-2,3-diarylxanthones (XH) bearing hydroxy groups on the two aryl rings. One-electron oxidation by superoxide radical-anions (ÎŁO2 -) and ÎŁTrp radicals as well as reaction with ÎŁCCl3O2 and ÎŁCHCl2O2 radicals demonstrates that two OH groups are required for efficient antioxidant reactivity in cetyltrimethylammonium bromide micelles. Hydroxy groups at the meta and para positions on either of the two phenyl rings confer enhanced reactivity, but XH bearing an OH at the para position of either phenyl ring is unreactive. While oxidation is favoured by OH in both meta and para positions of 2-aryl xanthone substituents, addition of a third and/or fourth OH enhances electron-donating capacity. In Cu2+-induced lipid peroxidation of human LDL, the lag period preceding the commencement of lipid peroxidation in the presence of XH bearing OH at meta and para positions on the 3-phenyl ring is extended to twice that observed with a comparable concentration of quercetin, a reference antioxidant. These antioxidants are also superior to quercetin in protecting human skin keratinocytes against tert-butylhydroperoxideinduced oxidative stress. While XH antioxidant activity in model biological systems is consistent with the structure–activity relationship, their response is also modulated by the localization of XH and by structural factors.This is Document No. NDLR-4864 from the Notre Dame Radiation Laboratory which is supported by the Office of Basic Energy Sciences at the United States Department of Energy. This work was supported by the Franco-Portuguese exchange programs GRICES-INSERM 2005-2006 and Pessoa 07958NF. P. Filipe thanks the “Sociedade Portugesa de Dermatologia e Venerologia” for a travel grant. Thanks are due to the University of Aveiro, “Fundação para a CiĂȘncia e a Tecnologia” and FEDER for funding the Organic Chemistry Research Unit. Clementina M. M. Santos thanks the Calouste Gulbenkian Foundation for the award of a short period research grant (proc 87872)

    Workmanship Training Industry

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    Special processes require special skills, knowledge and experienced application. For over 15 years, the NASA Johnson Space Center's Receiving, Inspection and Test Facility (RITF) has provided Workmanship Standards compliance training, issuing more than 500 to 800 training completion certificates annually. It is critical that technicians and inspectors are trained and that they maintain their proficiency to implement the applicable standards and specifications. Training services include 'hands-on' training to engineers, technicians, and inspectors in the areas of electrostatic discharge (ESD), soldering, fiber optics, lithium battery handling, torque and wire safety, and wire wrapping

    Intravascular ultrasound scanning improves long-term patency of iliac lesions treated with balloon angioplasty and primary stenting

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    AbstractPurpose: Underdeployment of an intravascular stent has been identified as a cause of restenosis or occlusion of a treated arterial lesion. Intravascular ultrasound (IVUS) has been shown to initially improve the anatomic and clinical stenting. The purpose of this study was to determine whether the use of IVUS increased long-term patency of this intervention. Methods: Between March 1992 and October 1995, 71 limbs (52 patients) with symptomatic aortoiliac occlusive disease underwent balloon angioplasty with primary stenting. IVUS and arteriography were used in 49 limbs (36 patients) to evaluate stent deployment. Arteriography alone was used in 22 limbs (16 patients) to evaluate stent deployment. Patients were captured prospectively in a vascular registry and retrospectively reviewed. Results: Mean age of patients treated with IVUS was 61.1 ± 9.0 years (range, 38-85) versus 70.0 ± 10.1 years (range, 57-87) in patients treated without IVUS (P <.01). There was no difference between the groups with respect to preoperative comorbidities, ankle-brachial indices, or number of stents per limb. Mean follow-up for IVUS patients was 62.1 ± 7.3 months (range, 15-81) and 57.9 ± 8.7 months (range, 8-80) for patients treated without IVUS (P = not significant). In 40% (20/49) of limbs, IVUS demonstrated inadequate stent deployment at the time of the original procedure. Kaplan-Meier 3- and 6-year primary patency estimates were 100% and 100% in the IVUS group and 82% and 69%, respectively, in limbs treated without IVUS (P <.001). There have been no secondary procedures performed in limbs treated with IVUS and a 23% (5/22) secondary intervention rate in the non-IVUS group (P <.05). Overall Kaplan-Meier survival estimates at 3 and 6 years for all patients were 84% and 67%, respectively. Conclusion: Balloon angioplasty and primary stenting of symptomatic aortoiliac occlusive lesions is a durable treatment option. Long-term follow-up of treated patients shows outcomes that are comparable with direct surgical intervention. IVUS significantly improved the long-term patency of iliac arterial lesions treated with balloon angioplasty and stenting by defining the appropriate angioplasty diameter endpoint and adequacy of stent deployment. (J Vasc Surg 2002;35:316-23.
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