Cold-hardy insects overwinter by one of two main strategies: freeze tolerance and freeze avoidance by supercooling. As a general model, many freeze-tolerant species overwinter in extreme climates, freeze above -10 degrees C via induction by ice-nucleating agents, and once frozen, can survive at temperatures of up to 40 degrees C or more below the initial freezing temperature or supercooling poi...

The technique of spray-freeze etching was applied to unicellular organisms. The superior freezing rates obtainable with this method gave excellent cryofixation on Chlorella, Euglena, and spermatozoa without the use of antifreeze agents, and cell damage due to ice crystal formation was never observed. In many instances the resultant morphology differed significantly from that obtained from glyce...

this study aimed to evaluate freeze-dried sera as an alternative to non-freeze dried for detection of anti-leishmania infantum antibodies over the course of 11 months using the direct agglutination test (dat).altogether, 60 serum samples (30 from humans and 30 from dogs) were collected from various geographical locations in iran. all the collected sera were pooled and each pooled serum sample c...

A set of freeze thresholds is defined which replaces the loosely defined element “killing frost.” Freeze series are tested and found to be random. This makes it possible to fit frequency distributions. It is hypothesized that these distributions are normal and a test of significance verifies this. A hypothesis that the variance parameter is constant over Iowa is tested and found to be true. It ...

Table of contents 1. Strategies of winter survival in animals 2. Freeze-induced gene expression 2.1. Freeze-induced gene expression in wood frogs 2.2. Freeze-induced gene expression in hatchling turtles and mitochondrial gene expression 3. Freeze tolerance, glucose metabolism and signal transduction 3.1. Unique glucose metabolism of freeze tolerant frogs 3.2. Structural modification of insulin ...

Microspheres formulated from poly (D,L-lactic-co-glycolide) (PLGA), a biodegradable polymer, have been extensively evaluated as a drug delivery system. In this study, the preparation, characterization and drug release properties of the PLGA microspheres were evaluated. Simvastatin (SIM)-loaded PLGA microspheres were prepared by oil-in-water emulsion/solvent evaporation method. The microspheres ...

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...