Citrus leaves exposed to subfreezing temperatures evolved ethylene at rates between 0.1 and 38.3 microliters per kilogram fresh weight per hour whereas untreated leaves evolved between 0.01 and 0.50 microliter per kilogram fresh weight per hour. Leaves not injured by freezing temperatures did not abscise, and ethylene evolution was near normal after 2 days. Freeze-injured leaves continued evolv...

waste tires, rubbers, plastic and steel materials, normally produced in every society, enter the environment and cause serious problems. these problems may, to some extent, be reduced by finding applications for them in engineering, for example, they can be used for geotechnical applications as backfill material and solving problems with low shear strength soils. such materials may be subjected...

BACKGROUND Although mouse spermatozoa can be freeze-dried without losing their reproductive capacity, the technique needs further improvements to reduce the incidence of chromosomal damage to spermatozoa. Effects of freeze-drying on human spermatozoa are unknown. METHODS Mouse spermatozoa were suspended in a Tris-buffered EGTA solution briefly (10 min at 37 degrees C) or for 1-7 days at 4 deg...

In the big vacuum freeze-drying equipment, the drying rate of materials is uneven at different positions. This phenomenon can be explained by the uneven distribution of vapor pressure in chamber during the freeze-drying process. In this paper, a mathematical model is developed to describe the vapor flow in the passageways either between material plates and in the channel between plate groups. T...

During normal sample preparation, storage in freezers and subsequent freeze/thaw cycles are commonly introduced. The effect of freeze/thaw cycles on the metabolic profiling of microalgal extracts using HR-MS was investigated. Methanolic extracts of monocultures of Arctic marine diatoms were analyzed immediately after extraction, after seven days of storage at -78 °C (one freeze/thaw cycle), and...

The ability of cells to survive freezing and thawing is expected to depend on the physiological conditions experienced prior to freezing. We examined factors affecting yeast cell survival during freeze-thaw stress, including those associated with growth phase, requirement for mitochondrial functions, and prior stress treatment(s), and the role played by relevant signal transduction pathways. Th...

the capability to preserve human oocytes, blastocysts, ovarian tissue and spermatozoa is an important tool in human assisted reproductive techniques. this preservation allows patients undergoing chemotherapy or radiotherapy to preserve their fertility, and helps to attain all benefits from the costly ovarian superovulation therapies prior to art. the primary goal in establishing an appropriate ...

SYNOPSIS The effects of nursery practices on freeze tolerance of P taeda and P elliottii seedlings were examined by placing the seedlings in a freezing chamber and lowering the temperature to -10C. Injury was evaluated 10 days after the freeze treatment by examining cambial tissue (browning test). Top-pruning P taeda seedlings (three times) increased freeze tolerance while rootwrenching (six ti...

Little information is available about the precise mechanisms and determinants of freeze resistance in baker's yeast, Saccharomyces cerevisiae. Genomewide gene expression analysis and Northern analysis of different freeze-resistant and freeze-sensitive strains have now revealed a correlation between freeze resistance and the aquaporin genes AQY1 and AQY2. Deletion of these genes in a laboratory ...