Comparison between the Reverse‐Flow Reactor and a Network of Reactors for the Oxidation of Lean VOC Mixtures

Catalytic reactors in forced nonstationary operation enable autothermal VOC (volatile organic compounds) oxidation even when the adiabatic temperature rise of the combustible mixtures is extremely low. The simulated moving bed (or ring reactor), realized with a network of two or three reactors, has been suggested as an alternative to the well‐investigated reverse‐flow reactor. The behavior of these configurations has been compared, showing that the reactor network has a narrower stability range than the reverse‐flow reactor; the stability range is decreased if we increase the number of reactors. The maximum temperature of the catalyst is higher in the network than in the reverse‐flow reactor and in both configurations it is increased if part of the catalyst is substituted by inert material.     

Effect of split doses of N-methyl-N-nitrosourea on DNA repair synthesis in cultured mammalian cells

DNA repair was measured in human fibroblasts, mouse C3H 10 T 1/2 fibroblsts and rat hepatocytes by the non-semi-conservative incorporation of [3H]-TdR during DNA repair synthesis using liquid scintillation techniques. Confluent monolayers of these cells grown on cover slips were exposed to split doses (125 or 250 microgram/ml) of the mutagenic and carcinogenic alkylating agent MNU and DNA repair synthesis compared with that produced by a single dose (500 microgram/ml). No significant difference in DNA repair capacity was detected in the three cell lines treated with a single dose or split doses of MNU.     

Lateral diffusion in planar lipid bilayers

Direct measurements by fluorescence correlation spectroscopy of lateral diffusion coefficients of fluorescent lipid analogs in lipid bilaryer membranes indicate self-diffusion coefficients D greater than 10(-7) square centimeters per second for various lipid systems above their reported transition temperatures. Cholesterol in egg lecithin at mole ratio of 1 : 2 reduces D by about twofold, while retained hydrocarbon solvent can increase it by two- to threefold.     

Significance of adrenal hormones in brain energy metabolism

Intensity of glycolysis was studied under conditions of immobilization stress and adrenalectomy as well as with administration of adrenaline and hydrocortisone. The processes of aerobic glycolysis, activity of enzymes of the tricarboxylic acid cycle and mitochondria respiratory chain, content of total, free and protein-bound glycogen, glucose-I-phosphate, glucose-6-phosphate, pyruvate, alpha-ketoglutarate, cytrate and macroergs in the brain are shown to depend on the level of adrenal hormones producing a multilateral effect on a series of energy metabolism links.     

A cannabinoid with cardiovascular activity but no overt behavioral effects

Abnormal-delta8-tetrahydrocannabinol (ABN-delta8-THC) failed to elicit central nervous system and cardiovascular effects in laboratory animals. Abnormal-cannabidiol (ABN-CBD) was also devoid of overt behavioral effects but produced marked hypotension with only slight bradycardia in anesthesized dogs.     

Further characterization of the complementation group B temperature-sensitive mutant of respiratory syncytial virus

ts-2, a temperature-sensitive and plaque morphology mutant of respiratory syncytial virus and sole representative of complementation group B, was compared with members of the other complementation groups of respiratory syncytial virus (group A [ts-1] and group C [ts-7]). ts-2 was found to be 10- to 1,000-fold more restricted in growth and ability to spread at restrictive temperatures (37, 38, and 39 degrees C) than at the permissive temperature (32 degrees C). In temperature shift-up experiments, the ts defect of ts-1 and other members of complementation group A was found to effect a late function that was required for at least 13 h in the replicative cycle. The ts lesion of ts-7 affected a function early in the replication cycle. In contrast, ts-2 was not temperature sensitive when studied by the shift-up technique. The discrepancy between the ts plaque property and failure to detect temperature sensitivity during the shift-up experiment was resolved when it was shown that ts-2 had a defect in adsorption or penetration or both at the restrictive temperature. Clonal analysis of revertant ts-2 showed a coordinate restoration of ts+ phenotype ans syncytium-forming capacity. It appears that ts-2 has a defect in a protein that is involved in adsorption and/or penetration of virus and is also responsible for cell fusion activity.     

Comparison of pethidine, buprenorphine and ketoprofen for postoperative analgesia after ovariohysterectomy in the cat

Sixty cats which underwent an ovariohysterectomy were randomly allocated into four treatment groups. One group (controls) received no analgesics postoperatively, and the others received either a single dose of buprenorphine (0.006 mg/kg) intramuscularly, or pethidine (5 mg/kg) intramuscularly, or ketoprofen (2 mg/kg) subcutaneously. The analgesia obtained after each treatment was assessed by three measures. There were significant differences between the groups both for the requirement for intervention analgesia (P = 0.0008) and for the overall clinical assessment (P = 0.0003) with ketoprofen requiring least intervention analgesia and having the best overall clinical assessment, followed by buprenorphine then pethidine. The control group required the most intervention analgesia and had the worst overall clinical assessment. Visual analogue scale scoring for pain produced significant differences between the groups from one hour after the operation, with the cats which were given ketoprofen tending to have lower pain scores than the other groups.