Effect of the Vibrational/Rotational Energy Partitioning on the Energy Transfer in Atom–Triatomic Molecule Collisions

The effect of the initial partitioning of the molecular energy between vibrational and rotational modes of a triatomic molecule on the collisional energy transfer is studied for a model atom–triatomic molecule system. We considered the collisions of thermal bath Ar atoms with SO2 molecules, and used the trajectory calculations for determining the energy transfer for three different samplings of initial conditions of the molecule. The first sampling method generated the microcanonical distribution over all states, entering into the vibrational and rotational manifolds, while two others produced distributions with relatively lower values of the rotational energies. It is shown that both the average energy transfer per collision and the mechanism of the energy exchange are significantly affected by the vibrational/rotational energy partitioning before the collisions. Relative decrease in the rotational energy results in the decrease of the averaged energy transfer and progressively emphasizes the role of active rotation as the gateway for translation-vibration energy exchange.     

2-Alkyl(aryl)-quinazolin-4(3H)-thiones, 2-R-(quinazolin-4(3H)-ylthio)carboxylic acids and amides: synthesis,molecular docking,antimicrobial and anticancer properties

In this study, a series of novel 2-alkyl(aryl)-quinazolin-4(3H)-thiones, 2-R-(quinazolin-4(3H)-ylthio)carboxylic acids and amides were synthesized and evaluated for antimicrobial and anticancer activities. Their structure was confirmed by elemental analysis and spectral data (FT-IR, LC-MS, ¹H-NMR). Antimicrobial activity was tested in vitro against Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Candida albicans and NCI in vitro preliminary anticancer activity against nine different cancer types. The most active antibacterial and antifungal compounds were: 2.1, 2.2 and 2.4. The introduction of the carboxylic acid or amide residue into the fourth position of quinazolin-4(3H)-thione resulted in the absence of antimicrobial activity. Substance 3.8 inhibited renal cancer UO-31 line and 2.18 – leukemia CCRF-CEM. The results of in silico molecular docking for DHFR and CK2 kinase had no correlation with in vitro properties, proposing the presence of other biological activity pathways.     

Allele polymorphism analysis of hemostasis and folate metabolism genes by real-time microchip PCR

Genetic diagnostics is widely used for detection of risk factors of hereditary thrombophilias caused by molecular defects in the coagulation system. The hereditary thrombophilias are frequently associated with higher incidences of point mutations in hemostasis (F2 20210G>A, F5 1691G>A) and folate metabolism (MTHFR 677C>T, MTHFR 1298A>C) genes. Combinations of gene abnormalities in F2 and/or MTHFR with Leiden mutation (F5 1691G>A) significantly increase risk of thrombosis. Thus, simultaneous analysis of allele polymorphism of these genes is of clinical importance. This study has demonstrated high efficiency of microchip-based multiplex real time PCR for analysis of allele specific polymorphism in hemostasis and folate metabolism genes. Using this test it is possible to analyze polymorphism of the three genes (four point mutations) in a short time; it requires a minimal quantity of DNA template and PCR reagents including DNA polymerase, and thus can be recommended for clinical laboratory diagnostics.     

Urease immobilization on macroporous silicas

Urease was immobilized on macroporous silicas using gamma-aminopropyl triethoxysilane and glutaraldehyde. The amount of protein on the surface, the structure of pores of the support and the purity of the initial enzyme were varied, the enzymic activity of the immobilized preparations being controlled. After the immobilization of sufficiently large quantities of the enzyme (about 3 mg protein per m2 support) about 35% of the specific activity was retained. The maximum activity per unit weight of the support was observed for silicagels and silochromes with the mean diameter of pores 70-90 nm and the specific surface area about 70 m2/g. The use of purified urease produced highly active preparations of the immobilized enzyme (17,000 U per g dry support). Freeze-drying of the immobilized enzyme in the presence of sorbitol yielded dry preparations retaining their activity.     

Pyramidal and extrapyramidal synaptic effects upon chronically deafferented motoneurons of the spinal cord of a cat

By means of intracellular recording technique, studies have been made of the electrical activity of -motoneurons of the seventh lumbar segment in cats with chronic rhizotomy of the dorsal root fibers (L₄-S₂). Postsynaptic potentials of the reticular formation of the midbrain, medulla, and ventral columns of the spinal cord were compared with the reactions recorded from nonoperated animals; these potentials were evoked by stimulation of the motor cortex, red nucleus, and Deuters' nuclei. Deafferentiation did not cause statistically reliable variations in the amplitude of the descending monosynaptic E PSPs. Extrapyramidal short-latent disynaptic E PSPs and IPSPs remained also practically unchanged, while the responses of deafferented motoneurons to cortico-spinal impulses were considerably facilitated; this effect was retained in pyramidal cats. Deafferentation was not accompanied by variations in the dependence of the discharge frequency on the depolarizing current strength or by the variation in the threshold and input resistance of the motoneuron membranes. This suggests that intensification of the pyramidal synaptic action upon deafferented motoneurons was caused by the variation on the intermediate neuronal level.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 1, No. 1, pp. 35–46, July–August, 1969.     

The selective participation of brain-specific non-histone proteins of chromatin Np-3,5 during the reproduction of a defensive habit to food in edible snails]

The role of brain-specific nonhistone proteins of chromatine Np-3.5 in the processes of reproduction of elaborated defensive habit to food was studied in previously learning snails. It was found, that gamma-globulines to Np-3.5 during tens of minutes inhibited behavioural and neuronal reactions elicited by a definite conditioned stimulus--carrot juice, without changing reactions to other conditioned stimulus--apple juice. gamma-globulines to other nonhistone proteins of chromatine did not influence the reproduction of food rejection habits. It was supposed that brain-specific nonhistone proteins of chromatine Np-3.5 were selectively involved in the molecular processes providing for neurophysiological mechanisms of information extraction from the long-term memory.     

Effect of diet on the lipid composition of cell nuclei and liver mitochondria during ontogenesis of the rat

The possible influence of the type of dietary fat on quantitative changes of different lipids in microsomes, nuclei and chromatin in hepatic cells of albino rats in ontogenesis was studied. While the type of diet had no significant influence on the levels of different phospholipids and fatty acids of nuclei, the type of dietary fat exerted definite effect on the levels of whole phospholipids, cholesterol of microsomes, nuclei and fatty acids of chromatin. The age specificity was observed in nuclear structures.     

Multi-factor analysis of combined effects of rifampicin and peptidoglycan of microbial origin on immune response]

Multifactorial analysis of the combined action of rifampicin and a microbial peptidoglycan on the immune response to antigens of the vaccine EV fraction 1 was performed. The results were computer-processed and the second order equations describing delayed hypersensitivity (DH) and antibody titers were derived. Nomographs or equal level curves showing interrelations of the investigated factors were plotted. The character of the combined action on DH and antibody titers was heterogeneous. The peptidoglycan had a pronounced immunostimulant action on DH and, to a lesser extent, influenced the humoral response. Conditions for the peptidoglycan use aimed at immunostimulation were optimized with application of multifactorial analysis.