نتایج جستجو برای: sperm coating
تعداد نتایج: 73758 فیلتر نتایج به سال:
Powder particle coating is the most important techni It has constantly being refined and modified since last four decades. There numerous applications of coating, including drug layering, modified release coating, physical and chemical protection, aesthetic purpos identification of drugs. Various coating techniques from conventional pan coating to laser assisted solvent free techniques have bee...
Post-copulatory sexual selection, in the form sperm competition, has influenced the evolution of several male reproductive traits. However, theory predicts that sperm competition would lead to trade-offs between numbers and size of spermatozoa because increased costs per cell would result in a reduction of sperm number if both traits share the same energetic budget. Theoretical models have prop...
OBJECTIVE To examine the relationship among sperm apoptosis, sperm chromatin status, and DNA ploidy in different sperm fractions. DESIGN Prospective study. SETTING Reproductive research center in a tertiary care hospital. INTERVENTION(S) Sperm prepared by density gradient were evaluated for sperm count, motility, apoptosis, and sperm chromatin assessment. MAIN OUTCOME MEASURE(S) Sperm c...
Sperm competition is now recognised as a potent selective force shaping many male reproductive traits. While the influence of sperm competition on sperm number is widely accepted, its effects upon sperm size remain controversial. It had been traditionally assumed that there is a trade-off between sperm number and sperm size, so that an increase in sperm number would result in a decrease in sper...
Of all the various locomotion strategies in low- R e $Re$ , traveling-wave propulsion methods with an elastic tail are preferred because they can be developed using simple designs and fabrication procedures. The only intrinsic property of that governs form rate wave propagation along its length is bending stiffness. Such traveling motion performed by spermatozoa, which possess a characterized v...
Sperm competition has classically been thought to maintain anisogamy (large eggs and smaller sperm) because males are thought to maximize their chance of winning fertilizations by trading sperm size for number. More recently it has been recognized that sperm quality (e.g., size, velocity) can also influence sperm competition, although studies have yielded conflicting results. Because sex evolve...
It is often questioned whether sperm parameters, including whether retrieved or ejaculated, have any effect on intracytoplasmic sperm injection (ICSI) results. Do severe spermatogenic defects affect embryo quality or pregnancy rate? Further, does it matter in azoospermic patients whether the sperm source is testicular or epididymal? Our studies show there is no significant difference in results...
A new instrument for assessing mammalian semen attributes, the Sperm Quality Analyzer, was evaluated as a potential tool for determining rooster sperm quality. The Sperm Quality Analyzer measures the “activity” of sperm in a semen sample as the sperm motility index (SMI). The SMI is defined as the number and amplitude of deflections in a light path per second as a result of sperm movement wit...
to improve the corrosion protection of copper metal, 0.01m concentration of 1h-1,2,4-triazole-3-thiol (tat) was incorporated into the hybrid sol-gel monolayers containing 3-glycidoxypropyltrimethoxysilane (gptms) and tetraethoxysilane (teos). it was further subjected to hydrolysis and condensation reaction to form a sol-gel matrix. the tat-doped hybrid sol-gel coating was applied over the coppe...
Sperm acquire the ability to fertilize in a process called capacitation and undergo hyperactivation, change motility pattern, which depends on Ca2+ transport by CatSper channels. is essential for fertilization it subjected complex regulation that not fully understood. Here, we report similar CatSper, Cdc42 distribution principal piece confined four linear domains this localization disrupted Cat...
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