Poly(gamma-D-glutamic acid) (PGA)-producing strains of Bacillus species were investigated to determine their ability to contribute to reducing the amount of ammonium nitrogen in liquid manures and their ability to convert some of the ammonium into this polyamino acid as a transient depot for nitrogen. Organisms that do these things should help solve the serious environmental problems which are ...

Preservation of spermatozoa is an important aspect of assisted reproductive medicine. The aim of this study was to investigate the efficacy and use of a recently developed liquid nitrogen and cryogen-free controlled rate freezer and this compared with the classical liquid nitrogen vapour freezing method for the cryopreservation of human spermatozoa. Ten patients entering the IVF programme donat...

Layered methane clouds in Titan’s troposphere with an upper methane ice cloud, a lower liquid methane–nitrogen cloud, and a gap in between were suggested from in situ measurements and ground-based observations. Here we report laboratory investigations under conditions that mimic Titan’s troposphere providing a detailed picture of the cloud layers. A solid methane cloud with a nitrogen content o...

Fungi are extremly diverse and beneficial organisms both for environment industry; thus we obliged to secure it’s biodiversity. There several laboratory methods fungi longterm preservation. The main goal is their vitality biological properties. Some of them simple but the same time laborious, other demand specific equipment. Among most popular find: freez-drying, cryopreservation at –80°C in li...

Ti Grade 2 was prepared by cryogenic attritor milling in liquid nitrogen and liquid argon. Two types of milling balls were used—stainless steel balls and heavy tungsten carbide balls. The effect of processing parameters on particle size and morphology, contamination of powder and its microhardness was investigated. Milling in liquid nitrogen was not feasible due to excessive contamination by ni...

To prepare tissues for analysis of NAD(+), NADH, NADP(+), and NADPH, common practice is to freeze samples in liquid nitrogen, often followed by freeze-drying, before extraction in HCl or NaOH. With cucumber (Cucumis sativus L.) cotyledons, prefreezing in liquid nitrogen or slower freezing to -20 degrees C yielded substantially lower values for NADH and NADPH than obtained from samples homogeniz...

2014 It was shown previously that a small volume of liquid nitrogen in front of a sharp metal tip can withstand an extremely high field without any sign of breakdown or charge injection. Subsequently, the influence of the tip radius on the critical field has been investigated and is described here. Also, by monitoring the injection, it has been possible to analyse the influence of the injected ...

Cryopreservation is the most promising way for long-term storage of biological samples e.g., single cells and cellular structures. Among various cryopreservation methods, vitrification is advantageous by employing high cooling rate to avoid the formation of harmful ice crystals in cells. Most existing vitrification methods adopt direct contact of cells with liquid nitrogen to obtain high coolin...

There have been several recent incidents involving the exploding of cryopreservation vials in Trust and Medical School laboratories. This occurs when liquid nitrogen (LN ) leaks into the vials and rapidly expands when removed from the tank. In one incident in our Medical School a research worker’s hand was injured. At Edinburgh University the lid of a cryovial was projected into a student’s eye...