948 resultados para Sperm preparation method
Resumo:
Background: Oxidative stress in reproductive system leads to sperm DNA damage and sperm membrane lipid peroxidation and may play an important role in the pathogenesis of male infertility, especially in idiopathic cases. Antioxidants such as carotenoids function against free radical damages. Objective: The aim of this study was to determine the levels of lycopene, beta-carotene and retinol in serum and their relationship with sperm DNA damage and lipid peroxidation in infertile and normospermic males. Materials and Methods: Sixty two infertile men and 71 normospermic men participated in this study. Blood and semen samples were collected from all subjects. Sperm DNA damage was measured using TUNEL method. Carotenoids, retinol, and malonedildehyde in serum were also determined. Results: DNA fragmentation was higher in infertile group comparing to control group. Serum levels of lycopene, beta-carotene and, vitamin A in infertile men were significantly lower than normospermic men (p< 0.001, =0.005, and =0.003 respectively). While serum MDA was not significantly different between two groups, MDA in seminal plasma of infertile men was significantly higher than control group (p< 0.001). Conclusion: We concluded that lycopene, beta-carotene, and retinol can reduce sperm DNA fragmentation and lipid peroxidation through their antioxidant effect. Therefore the DNA fragmentation assay and determination of antioxidants factors such as lycopene, beta-carotene and retinol, along with sperm analysis can be useful in diagnosis and treatment of men with idiopathic infertility.
Resumo:
The aim of this research are to know the effects of physiological NaCl dilution levels and storage duration on sperm motility and abnormality of Muscovy duck. Materials which used in this research were semen that collected of 1 - 1,5 years of four Muscovy duck. Semen were treated by physiological NaCl dilution levels nol , three, six and nine and storage duration ( t0 = 0 minute t1 =45minutes and t2=90 minute). Replication was three tapping periode . The method of this research was laboratory experimental with Randomized Complete Blok Design (RBD) in Split Plot Design (SPD) pattern ,as main plot is Physiological NaCl dilation levels and as sub plot is storage duration. Result of the experiment showed that physiological NaCl dilution levels was very significantly influences on sperm motility (p<0,01) and significantly influences and sperm abnormality (p<0,05) . The storage duration was very significantly influences and sperm motility and abnormality (p<0,01) .Orthogonal duration polynomial assayed showed that the effect of physiological NaCl dilution levels to sperm motility had a linier regression line with the a equation as Y =69.94 - 2.65 X,  r=0,49 R2=0.24 with Y presented to sperm motility and X represented to physiological NaCl dilution levels sperm and effect of storage duration to sperm motility had a linier regression line with the equation as Y =74.24-0.35 X, r =0.73 R2=0.53 with Y represented to sperm motility and X represented to storage duration . The effect of physiological NaCl dilution levels to sperm abnormality had a linier regression line with the equation as Y =5.61+0.34X, r=0.52 R2=0.27 with Y represented to sperm to abnormality and X represented to regression line with the equation as Y =6.74+0.01X, r=0.24R2=0.060 with Y represented to sperm abnormality and X represented to storage duration. It is can be concluded that a higher physiological NaCl dilation levels and storage duration caused sperm to motility decreased and sperm abnormality increased. (Animal Production 3(2): 45-52 (2001)Key Word: sperm Muscovy duck.
Resumo:
Fleck and Johnson (Int. J. Mech. Sci. 29 (1987) 507) and Fleck et al. (Proc. Inst. Mech. Eng. 206 (1992) 119) have developed foil rolling models which allow for large deformations in the roll profile, including the possibility that the rolls flatten completely. However, these models require computationally expensive iterative solution techniques. A new approach to the approximate solution of the Fleck et al. (1992) Influence Function Model has been developed using both analytic and approximation techniques. The numerical difficulties arising from solving an integral equation in the flattened region have been reduced by applying an Inverse Hilbert Transform to get an analytic expression for the pressure. The method described in this paper is applicable to cases where there is or there is not a flat region.
Resumo:
Titanium dioxide nanocrystals are an important commercial product used primarily in white pigments and abrasives, however, more recently the anatase form of TiO2 has become a major component in electrochemical and photoelectrochemical devices. An important property of titanium dioxide nanocrystals for electrical applications is the degree of crystallinity. Numerous preparation methods exist for the production of highly crystalline TiO2 particles. The majority of these processes require long reaction times, high pressures and temperatures (450–1400 °C). Recently, hydrothermal treatment of colloidal TiO2 suspensions has been shown to produce quality crystalline products at low temperatures (<250 °C). In this paper we extend this idea utilising a direct microwave heating source. A comparison between convection and microwave hydrothermal treatment of colloidal TiO2 is presented. The resulting highly crystalline TiO2 colloids were characterised using Raman spectroscopy, XRD, TEM, and electron diffraction. The results show that the microwave treatment of colloidal TiO2 gives comparable increases in crystallinity with respect to normal hydrothermal treatments while requiring significantly less time and energy than the hydrothermal convection treatment.