نتایج جستجو برای: gradient selected sperm

تعداد نتایج: 533627  

Journal: :Biomedical microdevices 2008
Linda Z Shi Jaclyn M Nascimento Charlie Chandsawangbhuwana Elliot L Botvinick Michael W Berns

An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sper...

Journal: :Biology letters 2009
Sara Calhim Helene M Lampe Tore Slagsvold Tim R Birkhead

Theories regarding the role of sexual selection on the evolution of sperm traits are based on an association between pre-copulatory (e.g. female preference) and post-copulatory (e.g. ejaculate quality) male reproductive traits. In tests of these hypotheses, sperm morphology has rarely been used, despite its high heritability and intra-individual consistency. We found evidence of selection for l...

Journal: :International journal of fertility and women's medicine 1999
R K Sharma K Seifarth D Garlak A Agarwal

OBJECTIVE In assisted reproduction, spermatozoa must be effectively separated from seminal plasma to undergo capacitation, a prerequisite for fertilization. Percoll was recently withdrawn from the American market because of safety concerns. The purpose of this study was to evaluate the quality of sperm separated by two different sperm washing media, and compare these results to sperm quality af...

Journal: :Journal of medical genetics 1978
S Sarkar O W Jones W Centerwall E T Tyler N Shioura

The range of variability in the population distribution characteristics of sperm DNA content was surveyed in a selected group of donors. The donors included identical twins, carriers of chromosomal translocations, and oligospermics. The DNA content of sperm was measured individually in an automated cytofluorometer. In contrast to normal donors with high sperm counts and relatively constant moda...

Journal: :Journal of andrology 2004
P Grasa R Pérez-Pé O Báguena F Forcada A Abecia J A Cebrián-Pérez T Muiño-Blanco

The objective of this study was to compare the efficacy of 2 dextran/swim-up media to increase the sperm quality parameters and the maintenance of these parameters at 15 degrees C and 30 degrees C over 6 hours. Additionally, this study examined whether differences in sperm quality reflect different reproductive efficiencies following intrauterine insemination in superovulated ewes. The study in...

Journal: :Reproduction in domestic animals = Zuchthygiene 2014
J M Morrell H Rodriguez-Martinez M Andersson

Semen from a Western Finncattle bull exhibiting a highly polymorphic spermiogram was processed by colloid centrifugation using Androcoll-B, a species-specific silane-coated silica colloid. In the first experiment, Single Layer Centrifugation (SLC) was used to identify which density colloids were needed to separate different cell populations. Colloids of the two chosen densities were then used i...

2012
Anat Bahat S. Roy Caplan Michael Eisenbach

On the basis of the finding that capacitated (ready to fertilize) rabbit and human spermatozoa swim towards warmer temperatures by directing their movement along a temperature gradient, sperm thermotaxis has been proposed to be one of the processes guiding these spermatozoa to the fertilization site. Although the molecular mechanism underlying sperm thermotaxis is gradually being revealed, basi...

Journal: :Fertility and sterility 2005
Attila Jakab Denny Sakkas Elena Delpiano Sevil Cayli Ertug Kovanci David Ward Alberto Revelli Gabor Huszar

OBJECTIVE To test a newly invented intracytoplasmic sperm injection (ICSI) sperm selection method based on sperm hyaluronic acid (HA) binding. DESIGN Comparison of chromosomal disomy and diploidy frequencies in sperm arising from semen and in HA-bound sperm. SETTING Academic andrology laboratory. PATIENT(S) Men presenting for semen analysis. INTERVENTION(S) Washed sperm fractions of 32 ...

Journal: :Advanced materials and technologies 2022

Selection of high-quality sperm is crucial to assisted reproduction. However, conventional clinical methods for selection are manual and prone operator errors. This article presents ‘sperm syringe', a scalable technology that mimics the highly parallelized 3D process in vivo via network 560 microchannels select sperm. Sperm syringe retrieves more than 41% healthy from initial sample under 15 mi...

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