Densities Of Cell Research Articles

Oxidation of styrene using a silent discharge plasma

Summary form only given, as follows. A cylindrically symmetrical dielectric barrier discharge was constructed to study the oxidation of styrene in the gas phase. Several operating parameters were varied to find the optimum conditions for styrene destruction. An argon/oxygen mix was used to generate the non-thermal plasma with oxygen concentrations ranging from 2-8%. The styrene concentrations ranged from 1000 ppm to 6000 ppm and energy densities of the SDP cell ranged from .5-3 kJ/liter. The temperature of the SDP cell was varied from 200/spl deg/C to 450/spl deg/C. The concentrations of styrene and its partial oxidation products were monitored by a CC-MS and the concentrations of CO/sub 2/ and CO were measured by FTIR. Destruction efficiencies of styrene up to 99.9% were measured.

Channels and pumps—determinants of metabolic cold adaptation strategies

1. 1. In all cells the passive diffusion of ions through transmembrane channels must be precisely balanced by the active transport of ions against concentration gradients, i.e., the ratio of ion channel/ion pump fluxes must be controlled at unity. 2. 2. One reason why some cells are cold sensitive is because temperature differentially affects these two processes and the necessary balance between them breaks down. 3. 3. Polar fishes apparently maintain channel/pump flux ratios at unity by upward adjustments in functional pump densities. 4. 4. That is presumably why their maintenance metabolic requirements are higher, which is an important cause of their higher-than-expected metabolic rates. This is the causal basis for the paradigm of metabolic cold adaptation in polar fishes. 5. 5. Channel/pump flux ratios of unity in principle also could be achieved in cold tolerant organisms by downward adjustments in functional channel densities of cell (and organelle) membranes. 6. 6. However, organisms utilizing this strategy would be expected to display profoundly reduced metabolic rates, reduced scopes for activity, and reduced osmoregulatory capacities. 7. 7. Deep sea fishes, also normally functional at low temperatures, display drastically reduced metabolic rates compared to other fishes and may well illustrate the latter strategy.