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Biomedical subjects

J R Rosowski

Publications and source records attributed to J R Rosowski.

3 recordsLinked to original sources
PubMed1995

Effect of microgravity and hypergravity on embryo axis alignment during postencystment embryogenesis in Artemia franciscana (Anostraca).

Cysts of brine shrimp attached with a liquid adhesive to 12-mm diameter glass coverslips in a syringe-type fluid processing apparatus were flown aboard the NASA space shuttle Discovery, flight STS-60, from 3-11 February 1994, and were allowed to undergo postencystment embryogenesis and to hatch in microgravity. The shuttle flight and the ground-based control coverslips with attached cysts were parallel to the earth's surface during incubation in salt water. Based on the position of the cyst shell crack in the attached cyst population, the ground-control nauplii emerged mostly upward. On the shuttle in microgravity, although our method of detection of orientation would not reveal emergence toward the coverslip, the ratio of the position of the cyst shell crack in the population after hatching best fit the predicted values of a random direction for nauplii emergence. Centrifugation on earth was then used to create hypergravity forces of up to 73 g during postencystment embryogenesis and hatching. The upward orientation of emerging nauplii showed a high degree of correlation (r(2) =98.8%) with a linear relationship to the log of g, with 78.2% of the total hatching upward at 1 g and 91.0% hatching upward at 73 g.

Animals↗
PubMed1980

Critical point drying: contamination in transitional fluid supply cylinders.

We call attention to the occurrence of an oily residue in the CPD bomb after critical point drying, as well as the presence of rust, dirt, and an oily residue in CO2 and Freon supply cylinders. Bottled gas is often tested for purity once after manufacturing and then is pumped and stored, perhaps several times, before the consumer's cylinders are filled. The cylinders may be in use for over 40 years, and may never be chemically cleaned, although they are hydrostatically pressure tested every five years, with the date of each test stamped on the cylinder. To the bottled gas industry we recommend regular inspection of tanks for bottom contamination, and vacuum and chemical cleaning when contamination is found. To users of bottled gas for critical point drying, we recommend becoming aware of the procedures of cylinder inspection, cleaning, and circulation among users. We suggest reporting to the gas supplier any contamination produced by inadvertently backfilling the supply cylinder. Although a common awareness of the problem of supply cylinder residues should lead to failures, the best assurance of clean, oil-free, dry liquid CO2 and other transitional fluids may be in the development of in-line filters which would remove particles, oil and moisture between the supply cylinder and the CPD bomb. We also suggest the use of gas grades higher than commercial, such as welding anhydrous (CO2) or specialty gases.

Gases↗