9 research outputs found

    NOS3 gene variants and male infertility: Association of 4a/4b with oligoasthenozoospermia

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    Results of recent studies confirmed that oxidative stress negatively affects sperm motility and causes sperm DNA damage. Produced by nitric oxide synthase 3 (NOS3), nitric oxide is considered to be one of the important mediators of oxidative stress in testis tissue. The aim of this study was to assess the possible association of three genetic variants (rs2070744, rs1799983 and intron variant 4a/4b) in NOS3 gene and infertility occurrence in two groups of infertile men (idiopathic azoospermia and oligoasthenozoospermia) and fertile controls. Genotypes for the single-nucleotide genetic variants rs1799983 and rs2070744 were determined by PCR-RFLP, while genotyping of intron 4 variant 4a/4b was performed by gel electrophoresis of PCR products. Statistical analysis was performed by SNPStats software. No significant association between the three genetic variants of the NOS3 gene and infertility risk was determined comparing allele and genotype frequencies among group of patients diagnosed with azoospermia and the control group. Nevertheless, there was a significant positive association between 4a/4b and infertility in the group of males diagnosed with oligoasthenozoospermia, under overdominant genetic model. Our findings suggest that tandem repeat variant within intron 4 of the NOS3 gene is associated with an increased risk of infertility in men diagnosed with idiopathic oligoasthenozoospermia.Andrologia (2017): e1281

    On the use of gamma irradiation crosslinked PVA membranes in hydrogen fuel cells

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    There is growing interest in the use of fuel cells (FC) with hydrogen as the main fuel for stationary, mobile, and transportation applications. In the FC concept membranes play increasingly important roles. Polymer electrolyte membrane fuel cells (PEMFCs) are considered as the most promising fuel cell technology for a wide range of applications due to the stable operation, the high energy generation yield and the simplicity of the system. In this work, we develop different types of membranes based on poly(vinyl alcohol) (PVA). PVA is a water-soluble polymer that is used in practical applications because of its easy preparation, excellent chemical resistance, thermal and mechanical properties. Crosslinking of the PVA was performed by gamma irradiation since radiation chemistry is found to be a very effective method for constructing three-dimensional polymeric networks. The samples prepared in this way were then immersed in the alkaline solution over a certain period of time to turn them into conductive membranes. Ionic conductivity of the PVA hydrogels, was then measured as a function of concentration of KOH solutions and temperature. Cyclic voltammetry of these PVA hydrogel electrolytes was performed to determine the width of the electrochemical stability window. We examined these membranes impregnated with saturated 6 M KOH electrolyte as polymer membrane for fuel cells application. Our experiments showed that PEMFCs with PVA and Nafion(R) membranes had similar polarization curves, under same conditions. Furthermore, PVA membranes proved to be stable during the real cell tests. This study offers a possibility for more earnest approach to the use of PVA membranes for fuel cell applications. (C) 2007 Elsevier B.V. All rights reserved

    The Association Between Periodontal Inflammation and Labor Triggers (Elevated Cytokine Levels) in Preterm Birth: A Cross-Sectional Study

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    Background: Periodontitis is considered to be a risk factor for preterm birth. Mechanisms have been proposed for this pathologic relation, but the exact pathologic pattern remains unclear. Therefore, the objective of the present study is to evaluate levels of four major labor triggers, prostaglandin E-2 (PGE(2)), interleukin (IL)-1 beta, IL-6, and tumor necrosis factor (TNF)-alpha, in gingival crevicular fluid (GCF) and serum samples between women with preterm birth (PTB) and full-term birth (FTB) and correlate them with periodontal parameters. Methods: PGE(2), IL-1 beta, IL-6, and TNF-alpha levels were estimated using enzyme-linked immunosorbent assays in GCF and serum samples collected 24 to 48 hours after labor from 120 women (60 FTB, 60 PTB). Results: Women with PTB exhibited significantly more periodontitis, worse periodontal parameters, and increased GCF levels of IL-6 and PGE(2) compared with the FTB group; there were no significant differences in serum levels of measured markers. GCF levels of IL-1 beta, IL-6, and PGE(2) and serum levels of TNF-alpha and PGE(2) were significantly higher in women with periodontitis compared with periodontally healthy women. Serum levels of PGE(2) were positively correlated with probing depth (PD) and clinical attachment level (CAL) as well as with GCF levels of TNF-alpha in women with PTB. Conclusions: Women with PTB demonstrated worse periodontal parameters and significantly increased GCF levels of IL-6 and PGE(2) compared with those with FTB. Based on significant correlations among serum PGE(2) and PD, CAL, and GCF TNF-alpha in PTB, periodontitis may cause an overall increase of labor triggers and hence contribute to preterm labor onset

    Negative influence of Ag and TiO2 nanoparticles on biodegradation of cotton fabrics

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    Recently, many efforts have been made to efficiently impregnate different textile materials with metal and metal oxide nanoparticles in order to provide antimicrobial, UV protective or self-cleaning properties. Evidence of their environmental risks is limited at this point. The aim of this study was to explore the influence of Ag and TiO2 nanoparticles on biodegradation of cotton fabrics. Biodegradation behavior of cotton fabrics impregnated with Ag and TiO2 NPs from colloidal solutions of different concentrations was assessed according to standard test method ASTM 5988-03 and soil burial test. Degradation of cotton fabrics was also evaluated by enzymatic hydrolysis with cellulase. The morphology of fibers affected by biodegradation was analyzed by scanning electron microscopy (SEM). In order to get better insight into biodegradation process, dehydrogenase activity of soil has been determined. Ag and particularly TiO2 nanoparticles suppressed the biodegradation of cotton fabrics. The dehydrogenase activity of soil with cotton fabrics impregnated with TiO2 nanoparticles was the weakest. Severe damage of cotton fibers during the biodegradation process was confirmed by SEM
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