نتایج جستجو برای: sperm preparation
تعداد نتایج: 211534 فیلتر نتایج به سال:
Background: Cryopreservation has adverse effect on human spermatozoa via exposure to physical and chemical stress that may lead to alter in reactive oxygen species (ROS) levels. During sperm preparation or cryopreservation, centrifugation as a physical stress may effect on sperm quality probably with stress oxidative production and membrane damage. Therefore the aim of this study was to evaluat...
the current study aimed at investigating the relationship between motivation and test preparation strategies (tpss) used by iranian pre-university students in their preparation period for the university entrance exam (uee). due to the importance of uee in iran, this study also attempted to show its impact on these two important variables. to this end, 100 pre-university students in an iranian p...
abstract recent studies suggest that prelistening activities play an important role in the development of listening comprehension (e.g. long 1990;chiang and dunkel 1992; schmidt-rinehart 1994; jensen and hansen 1995; robinson et al., 1995; buck, 1995; foster and skehan,1996; teng 1996; robinson, 2001; chang and read 2006). in line with previous studies and to shed light on a new aspect of sche...
Research has revealed that reactive oxygen species (ROS) negatively affect sperm function, both in vivo and in vitro. Sperm preparation techniques for assisted reproductive technologies (ART) are potential causes for additional ROS production. This study aimed to correlate the concentration of exogenous H(2)O(2) with sperm motility parameters and intracellular ROS and nitric oxide (NO) levels t...
A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are density-gradient centrifugation (DGC) and swim-up (SUP). To date, these methods appear to be effective in selecting functional sperm for assisted reproduction techniques (ART), but they may have negative effects on sperm DNA. In this study, the ability of these semen proces...
In modern livestock breeding, cryopreserved semen is routinely used for artificial insemination. Sperm cryopreservation secures future reproduction, and insemination doses can be easily shipped. Processing of semen for cryopreservation can be done with minimal efforts and relatively low costs. In this chapter we describe the entire cryopreservation process for stallion and bull sperm including ...
PURPOSE Sperm processing (e.g., centrifugation) used in preparation for assisted reproduction can result in excessive generation of reactive oxygen species (ROS) and potential sperm damage. The use of antioxidants during sperm processing has been shown to prevent iatrogenic sperm damage, including DNA damage. In this study, we evaluated the effect of caffeic acid phenethyl ester (CAPE) on oxida...
T. Schedl (ed.), Germ Cell Development in C. elegans, Advances in Experimental Medicine and Biology 757, DOI 10.1007/978-1-4614-4015-4_7, © Springer Science+Business Media New York 2013 Abstract During spermatogenesis, pluripotent germ cells differentiate to become ef fi cient delivery vehicles to the oocyte of paternal DNA. Though male and female germ cells both undergo meiosis to produce hapl...
Sea urchin egg fertilization requires the species-specific interaction of molecules on the sperm and egg surfaces. Previously, we isolated an extracellular, 70-kD glycosylated fragment of the S. purpuratus egg receptor for sperm by treating the eggs with lysylendoproteinase C (Foltz, K. R., and W. J. Lennarz. 1990. J. Cell Biol. 111:2951-2959). To characterize the receptor further, we have gene...
OBJECTIVE To examine simultaneously the levels of hydrogen peroxide (H(2)O(2)) and superoxide (O(2)(-*)) using chemiluminescence and flow cytometry. DESIGN Prospective laboratory study. SETTING Reproductive research lab in a tertiary hospital. PATIENT(S) Semen samples from 18 healthy male volunteers. INTERVENTION(S) Sperm preparation and measurement of reactive oxygen species (ROS) by c...
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