88 research outputs found

    Role of Neural NO Synthase (nNOS) Uncoupling in the Dysfunctional Nitrergic Vasorelaxation of Penile Arteries from Insulin-Resistant Obese Zucker Rats

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    Objective: Erectile dysfunction (ED) is considered as an early sign of vascular disease due to its high prevalence in patients with cardiovascular risk factors. Endothelial and neural dysfunction involving nitric oxide (NO) are usually implicated in the pathophysiology of the diabetic ED, but the underlying mechanisms are unclear. The present study assessed the role of oxidative stress in the dysfunctional neural vasodilator responses of penile arteries in the obese Zucker rat (OZR), an experimental model of metabolic syndrome/prediabetes. Methods and Results: Electrical field stimulation (EFS) under non-adrenergic non-cholinergic (NANC) conditions evoked relaxations that were significantly reduced in penile arteries of OZR compared with those of lean Zucker rats (LZR). Blockade of NO synthase (NOS) inhibited neural relaxations in both LZR and OZR, while saturating concentrations of the NOS substrate L-arginine reversed the inhibition and restored relaxations in OZR to levels in arteries from LZR. nNOS expression was unchanged in arteries from OZR compared to LZR and nNOS selective inhibition decreased the EFS relaxations in LZR but not in OZR, while endothelium removal did not alter these responses in either strain. Superoxide anion production and nitro-tyrosine immunostaining were elevated in the erectile tissue from OZR. Treatment with the NADPH oxidase inhibitor apocynin or acute incubation with the NOS cofactor tetrahydrobiopterin (BH4) restored neural relaxations in OZR to levels in control arteries, while inhibition of the enzyme of BH4 synthesis GTP-cyclohydrolase (GCH) reduced neural relaxations i

    A multiple timepoint pre-post evaluation of a ‘sexual respect’ dvd to improve competence in discussing sex with patients with disability

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    Sexual problems are common after chronic illnesses and disability, yet research indicates that this is a neglected area in healthcare services. Evaluation studies provide evidence of the effectiveness of education in enhancing professionals’ knowledge, skills, and comfort in addressing patients’ sexual concerns. However, there are limited evaluations aimed at improving ability to discuss sexuality when working with people with disabilities. The overall aim of this study was to evaluate a ‘Sexual Respect’ DVD as an intervention to improve competence in addressing ‘sexuality and disability’. A mixed methods design was used with both quantitative and qualitative components. Nursing students’ self-report ratings of knowledge, confidence, comfort and willingness (to discuss sexuality) levels were collected across four time points: baseline, pre-intervention, post-intervention, and follow-up. Data were analysed using one-way repeated measures ANOVAs with post hoc comparisons. Open-ended qualitative comments relating to the barriers and facilitators to discussing sexuality were analysed using content analysis and subsequent frequency analysis. Reported barriers included lack of knowledge about sex¬uality and disability issues, the patient’s level of disability, and waiting for the patient to raise sexuality issues first. Facilitators included education/training, written information, and if the patient raised it first. Overall, the DVD intervention had a significant and positive impact on nursing students’ self-reported knowledge, confidence, comfort and willingness levels. The findings are discussed in relation to the PLISSIT model, which emphasises the importance of a proactive approach to addressing sexuality issues

    Nitrergic and noradrenergic interaction in dually innervated organs

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    SIGLEAvailable from British Library Document Supply Centre-DSC:DXN021017 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    High responsivity InP-InGaAs quantum-well infrared photodetectors: Characteristics and focal plane array performance

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    We report the detailed characteristics of long-wavelength infrared InP-In0.53Ga0.47As quantum-well infrared photodetectors (QWIPs) and 640 x 512 focal plane array (FPA) grown by molecular beam epitaxy. For reliable assessment of the detector performance, characterization was performed on test detectors of the same size and structure with the FPA pixels. Al0.27Ga0.73As-GaAs QWIPs with similar spectral response (lambda(p) = similar to 7.8 mu m) were also fabricated and characterized for comparison. InP-InGaAs QWIPs (20-period) yielded quantum efficiency-gain product as high as 0.46 under -3-V bias with a 77-K peak detectivity above 1 x 10(10) cm center dot Hz(1/2)/W. At 70 K, the detector performance is background limited with f/2 aperture up to similar to 3-V bias where the peak responsivity (2.9 A/W) is an order of magnitude higher than that of the AlGaAs-GaAs QWIP. The results show that impact ionization in similar InP-InGaAs QWIPs does not start until the average electric-field reaches similar to 25 kV/cm, and the detectivity remains high under moderately large bias, which yields high responsivity due to large photoconductive gain. The InP-InGaAs QWIP FPA offers reasonably low noise equivalent temperature difference (NETD) even with very short integration times (tau).70 K NETD values of the FPA with f/1.5 optics are 36 and 64 mK under bias voltages of -0.5 V (tau = 11 ms) and -2 V (tau = 650 mu s), respectively. The results clearly show the potential of InP-InGaAs QWIPs for thermal imaging applications requiring high responsivity and short integration times

    Assessment of large format InP/InGaAs quantum well infrared photodetector focal plane array

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    We report the fabrication and characteristics of large format (640 x 512) InP/In0.53Ga0.47As long wavelength infrared (LWIR) quantum well infrared photodetector (QWIP) focal plane array (FPA). The FPA, which is hybridized to a read-out integrated circuit having a charge capacity of 1.1 x 10(7) electrons, yielded a mean noise equivalent temperature difference (NETD) of similar to 40 mK at a cold finger temperature as high as 77 K. The performance of the FPA, being comparable to that of AlGaAs/GaAs QWIP FPAs, clearly demonstrates the feasibility of the InP/InGaAs material system as an Al-free alternative to AlGaAs/GaAs system for large format LWIR QWIP FPAs
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