149 research outputs found

    An amorphous silicon photodiode array for glass-based optical MEMS application

    Get PDF
    A highly sensitive photo-detector array deposited on a glass substrate with an optional integrated optical filter have been presented. The active element is a vertically integrated hydrogenated amorphous silicon photodiode featuring a dark current of less than 1e-10 A/cm2 for -3V polarization and a maximal quantum efficiency of 80% near 580 nm. The prototype was encapsulated and successfully tested optically. It has a fill factor of only 44% which, however, can be easily increased to 90% using flip-chip bonding to an integrated electronic circuit for signal conditioning. The sensor is biocompatible and can be integrated with other glass-based and glass compatible micro-fabricated devices such as optical, microfluidic, lab-on-a-chip, chemical and biological devices in which photo-detection is a desired feature. ©2009 IEEE

    Protective effect of cerium oxide nanoparticle on sperm quality and oxidative damage in malathioninduced testicular toxicity in rats: An experimental study

    Get PDF
    Background: Malathion is an organophosphorus pesticide that commonly used in many agricultural and non-agricultural processes. Previous studies have reported the effects of melatonin on the reproductive system. Cerium dioxide nanoparticles (CeNPs) due to their antioxidative properties are promising to impact on the development of male infertility. Objective: The aim of this study was to evaluate the effect of CeNPs on oxidative stress and sperm parameters after malathion exposure of male rats. Materials and Methods: 36 adult male Wistar rats were divided into 6 groups (n=6/each): Control, CeNPs -treated control (15 and 30 mg/kg/day), malathion (100 mg/ kg/day), and CeNPs -treated malathion groups (15 and 30 mg/ kg/day). At the end of the study (4 wk), the sperm counts, motility, and viability in the testis of rats were measured, also lipid peroxidation, total antioxidant capacity, and total thiol groups in homogenate testis were investigated. Results: Malathion significantly reduced sperm count, viability, and motility than the control rats (p<0.001). Co-treatment of malathion with CeNPs 30 mg/kg had a protective effect on sperm counts (p=0.03), motility (p=0.01), and viability (p<0.001) compare to malathion group. Also, the results showed that malathion reduced testis total anti-oxidant capacity, the total thiol group, and increased testis malondialdehyde than the control rats (p<0.001). CeNPs 30 mg/kg are increased total antioxidant capacity (p<0.001) and total thiol group (p=0.03) compared to malathion group. CeNPs at both doses (15 and 30 mg/kg) improved malondialdehyde than the malathion group (p<0.001 and p=0.01 respectively). Conclusion: CeNPs 30 mg/kg administered considerably restored testicular changes induced by malathion. The improvement of oxidative stress by CeNPs may be associated with increased sperm counts, motility and viability in the testis. © 2018, Research and Clinical Center for Infertitlity. All rights reserved

    Tempol improves oxidant/antioxidant parameters in testicular tissues of diabetic rats

    Get PDF
    Aims: Oxidative stress induced by diabetes mellitus (DM) is considered as one of the main causes of infertility in diabetic patients. The aim of the present study was to assess the effect of Tempol � as a synthetic antioxidant- on the testis oxidative stress and sperm parameters in type 2 diabetic (T2D) rats. Main methods: Twenty male Wistar rats were divided into 4 groups. Control groups (C) and diabetic groups (D); the control and diabetic groups received Tempol (100 mg/kg) for one month. Sperm parameters and oxidative stress biomarkers were evaluated in testicular tissue. Key findings: The results demonstrated that administration of Tempol in diabetic rats improved sperm motility and viability and decreased the count of abnormal sperms. Also Tempol decreased the fasting blood sugar (FBS) and lipid peroxidation (LPO). In addition, Tempol significantly increased total antioxidant capacity (TAC) levels in testis tissue of T2D rats. Histopathological changes were also improved in the diabetic treated group. Significance: Taken together, the results indicated that Tempol improved fertility parameters in a diabetic rat through reducing oxidative stress. © 2019 Elsevier Inc

    Helping students to self-care and enhance their health-promotion skills.

    Get PDF
    Nurses have a public health role, requiring them to promote the health of individuals and communities, and to engage at a political and policy level to improve population health. There is also a professional expectation that nurses will model healthy behaviours and take responsibility for their personal health and wellbeing. However, studies have indicated that undergraduate nurses find the academic and practice elements of their nursing programmes stressful. To manage their stress many use coping behaviours that negatively impact on their health and wellbeing and may influence their ability and willingness to effectively support health promotion in practice. It is widely recognised that environments influence health outcomes and personal health behaviours. This article addresses some of the structural causes of student nurse stress and highlights a recent educational initiative at a UK university that aims to equip student nurses with the practical skills required to engage in health promotion and thereby provide benefits for service users and student nurses alike

    Heat treatment of cold-sprayed C355 Al for repair: microstructure and mechanical properties

    Get PDF
    Cold gas dynamic spraying of commercially pure aluminum is widely used for dimensional repair in the aerospace sector as it is capable of producing oxide-free deposits of hundreds of micrometer thickness with strong bonding to the substrate, based on adhesive pull-off tests, and often with enhanced hardness compared to the powder prior to spraying. There is significant interest in extending this application to structural, load-bearing repairs. Particularly, in the case of high-strength aluminum alloys, cold spray deposits can exhibit high levels of porosity and microcracks, leading to mechanical properties that are inadequate for most load-bearing applications. Here, heat treatment was investigated as a potential means of improving the properties of cold-sprayed coatings from Al alloy C355. Coatings produced with process conditions of 500 °C and 60 bar were heat-treated at 175, 200, 225, 250 °C for 4 h in air, and the evolution of the microstructure and microhardness was analyzed. Heat treatment at 225 and 250 °C revealed a decreased porosity (~ 0.14% and 0.02%, respectively) with the former yielding slightly reduced hardness (105 versus 130 HV0.05 as-sprayed). Compressive residual stress levels were approximately halved at all depths into the coating after heat treatment, and tensile testing showed an improvement in ductility

    Juggling to find balance: hearing the voices of undergraduate student nurses.

    Get PDF
    BACKGROUND: Accounts of stress are common among students on nursing programmes. Prolonged high levels of stress can contribute to poor learning, the development of detrimental health behaviours, attrition and burnout. AIMS: To examine the health and wellbeing implications of undertaking a BSc nursing degree in the UK for first-year students. METHODS: Qualitative narrative analysis of 100 written student reflections on the influences on their health and wellbeing was undertaken. FINDINGS: Nursing students must juggle multiple competing demands on their physical capabilities, personal resources, income and time. Students are constantly seeking to achieve balance and personal equilibrium through the use of a variety of coping strategies. CONCLUSION: This work calls upon the profession, the nursing regulator, nursing programmes within higher education institutions and health Trusts to review the framework and content of undergraduate BSc nurse education. Programme requirements should enhance the health and wellbeing of students while simultaneously delivering education and practice opportunities necessary to meet professional requirements
    • …
    corecore