Simulating heat and mass transfer in regular distillation column packing

Plane-parallel packing of Mellapack 250X type (without perforations) is considered. Equation systems are given that describe the motion and heat and mass transfer in a layer of liquid and vapor. Calculations have been performed on nonstationary heat and mass transfer in cells of several types by the use of the STAR-CD software and the subroutines Star-Design and Pro-amm. Graphs are given for the velocity and vapor pressure distributions in cells of circular and triangular shape, as well as for the oxygen distribution in circular cells.     

In vivo transfer of14C-4-cholesterol from mouse host to encapsulatedTrichinella spiralis larvae

Mice infected for four months with the parasiteTrichinella spiralis were fed 4-¹⁴C-cholesterol. The encapsulated larvae were then collected from the mice, and the lipids of the larvae were extracted and fractionated by thin layer chromatography (TLC). One of the TLC bands known to contain cholesterol was subfractionated; the resulting bands were assayed for radioactivity. It was found that the pure cholesterol fraction contained radioactive cholesterol, presumably from the host.     

The Effect of Low-Energy Laser-Driven Ultrashort Pulsed Electron Beam Irradiation on Erythropoiesis and Oxidative Stress in Rats

Anemia is a commonly observed consequence of whole-body exposure to a dose of X-ray or gamma irradiation of the order of the mean lethal dose in mammals, and it is an important factor for the determination of the survival of animals. The aim of this study was to unravel the effect of laser-driven ultrashort pulsed electron beam (UPEB) irradiation on the process of erythropoiesis and the redox state in the organism. Wistar rats were exposed to laser-driven UPEB irradiation, after which the level of oxidative stress and the activities of different antioxidant enzymes, as well as blood smears, bone marrow imprints and sections, erythroblastic islets, hemoglobin and hematocrit, hepatic iron, DNA, and erythropoietin levels, were assessed on the 1st, 3rd, 7th, 14th, and 28th days after irradiation. Despite the fact that laser-driven UPEB irradiation requires quite low doses and repetition rates to achieve the LD₅₀ in rats, our findings suggest that whole-body exposure with this new type of irradiation causes relatively mild anemia in rats, with subsequent fast recovery up to the 28th day. Moreover, this novel type of irradiation causes highly intense processes of oxidative stress, which, despite being relatively extinguished, did not reach the physiologically stable level even at the 28th day after irradiation due to the violations in the antioxidant system of the organism.