objective: vitrification has been shown as one of the most effective methods of cryopreservation for mammalian embryos. however, there is no consensus which stage of embryonic development is the most appropriate for vitrification with subsequent maximal development after thawing. this study was carried out to explore and compare the effect(s) of vitrification on mouse 2-cell, 4-cell, 8-cell, mo...

introduction: this study was designed to compare the effects of three vitrification procedures [conventional (c), open pulled straw (ops) and closed pulled straw (cps)] on morphological survival of two-cell mouse embryos and their subsequent development to hatched blastocysts. material and methods: two-cell mouse embryos were divided into four groups, control (194), ops (150), cps (155) and c (...

Extended semen from six Hereford bulls was placed in .25-ml Continental straws and frozen in the vertical position. Treatments were arranged factorially with glycerol levels of 5, 7, 9 or 11%; semen cooled from 5 to 1 3 0 C in 3.5 (fast), 20 (moderate) or 40 min (slow); and thawed in water at 5 C for 3 min, 35 C for 12 sec, 55 C for 8 sec, 75 C for 7 sec or 90 C for 5 seconds. Fast freezing res...

1. The hemagglutinating capacity, enzymic activity, and infectivity of several influenza viruses were destroyed by repeated freezing and thawing of dialyzed allantoic fluids containing them. 2. Influenza virus degraded by freezing and thawing, by treatment with 5 M urea, or by heating at 65 degrees C. still combined with homologous antibody and was demonstrable by blocking of the hemagglutinati...

Boar sperm TyrP32 is a 32-kDa tyrosine-phosphorylated protein that increases during the capacitation and acrosome reaction and during cryocapacitation. However, it is still unclear whether the increase in TyrP32 is an event that is limited to the process of sperm fertilization, including cryocapacitation. The aims of the present study were to demonstrate that TyrP32 is increased in dead spermat...

Generally speaking, the literature indicates that the number of bacteria surviving subfreezing temperatures will be functions of: (1) initial numbers of viable cells present when frozen (Record and Taylor, 1953; Kropp, 1950), (2) the rate of the freezing and thawing process (Luyet and Gehenio, 1940), (3) the temperature of storage, with 0 to -20 C being more destructive than the range below -20...

Microbial N2O release during the course of thawing of soil was investigated in model experiment focusing on denitrification, since freeze-thaw has been shown to cause significant physical and biological changes in soil, including a surge of N2O and CO2. The origin of these is still controversially discussed. The increase in denitrification after thawing may be attributed to the diffusion of org...

Future climate will alter the soil cover of mosses and snow depths in the boreal forests of eastern Canada. In field manipulation experiments, we assessed the effects of varying moss and snow depths on the physiology of black spruce (Picea -mariana (Mill.) B.S.P.) and trembling aspen (Populus tremuloides Michx.) in the boreal black spruce forest of western Québec. For 1 year, naturally regenera...

BACKGROUND Iron deficiency (ID) may impair long-term neurological development when it occurs in young infants. In cohort studies, it is sometimes necessary to evaluate ID with sera kept frozen for several years. To assess ID, learned societies recommend measuring serum ferritin (SF) level combined with C-reactive protein level. The long-term stability of C-reactive protein in frozen samples is ...