A New Species of the Genus Colilodion Besuchet (Coleoptera: Staphylinidae: Pselaphinae) from Vietnam

A new pselaphine species, Colilodion thienmu n. sp., is described from Mt. Bach Ma in Central Vietnam. SEM photographs of this species are provided and morphological notes are given in this study.     

Influence of substituent effects on spectroscopic properties and antimicrobial activity of 5-(4��-substituted phenylazo)-2-thioxothiazolidinone derivatives

5-(4??-substituted phenylazo)-2-thioxothiazolidinone derivatives (HL_n) have been synthesized and characterized by elemental analysis, spectra (IR, electronic and ¹H NMR). The IR spectral data indicate that the compounds can exist in two resonance structures. The synthesized ligands were screened for their antimicrobial activity against four bacterial species, two Gram positive bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae) as well as against some species various of fungi; Aspergillus niger, Penicillium chrysogenum, Penicillium italicum and Fusarium oxysporium. The results showed that most these ligands are good antibacterial agents against B. cereus and S. aureus and antifungal agents against A. niger and F. oxysporium. HL₃ was found to be the most effect compound against all tested microorganisms. The size of clear zone were ordered as follows p-(OCH₃?<?CH₃?<?H?<?Cl?<?NO₂) as expected from Hammett??s constant ??^R.     

Synthesis of 5-Alkyl-5-methyl-2-hydroxy-2-cyclopentenones

A hydrogen bacterium strain, N34, and its oxygen-resistant segregant strain, Y38, were subjected to a taxonomical study. Since both strains were capable of N₂-fixation, N₂-fixing facultative hydrogen autotrophs listed in “Bergey’s Manual of Systematic Bacteriology” were used for comparison. Both strains produced a water-insoluble carotenoid pigment, zeaxanthin dirhamnoside, indicating that both should be classified into the genus Xanthobacter. Then, the differential characteristics of the two species of the genus Xanthobacter, X. autotrophicus and X. flavus, were investigated as to both strains. The vitamin requirement, the sensitivity to oxygen under autotrophic conditions, the inducibility of hydrogenase, the substrate range of carbohydrates and N₂-fixing growth characteristics of both strains were almost completely opposite to those of X. flavus. Moreover, both strains coincided exactly with X. autotrophicus in morphological and other physiological characteristics. From these results both strains were identified as Xanthobacter autotrophicus.     

Hydrocarbon biodegradation and surfactant production by acidophilic mycobacteria

Production of biosurfactants by acidophilic mycobacteria was demonstrated in the course of aerobic degradation of hydrocarbons (n-tridecane, n-tricosane, n-hexacosane, model mixtures of С₁₄–С₁₇, С₁₂?С₁₉, and С₉–С₂₁n-alkanes, 2,2,4,4,6,8,8-heptamethylnonane, squalane, and butylcyclohexane) and their complex mixtures (hydrocarbon gas condensate, kerosene, black oil, and paraffin oil) under extremely acidic conditions (pH 2.5). When grown on hydrocarbons, the studied bacterial culture AG_S10 caused a decrease in the surface and interfacial tension of the solutions (to the lowest observed values of 26.0 and 1.3 mN/m, respectively) compared to the bacteria-free control. The rheological characteristics of the culture changed only when mycobacteria were grown on hydrocarbons. Neither the medium nor the cell-free culture liquid had the surfactant activity, which indicated formation of an endotype biosurfactant by mycobacteria. Biodegradation of n-alkanes was accompanied by an increase in cell numbers, surfactant production, and changes in the hydrophobicity of bacterial cell surface and in associated phenomena of adsorption and desorption to the hydrocarbon phase. Research on AGS10 culture liquids containing the raw biosurfactant demonstrated the preservation of its activity within a broad range of pH, temperature, and salinity.     

MHD Waves and Instabilities in Two-Component Anisotropic Plasma

Plasma Physics Reports - Based on the 16-moment MHD transport equations, the propagation of linear waves in an anisotropic homogeneous cosmic plasma is considered. A general dispersion relation is...     

Effect of low-energy microwaves on DNA stability in solution

DNA isolated from liver of healthy and tumor-bearing (sarcoma 45) rats was irradiated in water-salt solution with weak microwaves (64.5 GHz, 50 μW/cm²). The heat stability of DNA increased with irradiation time (a raise of 1.5°C in T _m for “tumor” DNA after 90 min, without changes in ΔT), which may be associated with dehydration of the surrounding Na⁺ ions.     

A Study of the Structure of Trypsin-Like Serine Proteinases. 2. A Study of Tryptophan Fluorescence in Variants of Miniplasminogen with an Altered Primary Structure

Biophysics - Abstract—Variants of miniplasminogen with an altered primary structure have been designed to study previously described changes in tryptophan fluorescence during plasminogen...     

Lysozyme activity in the leukocytes and blood serum of white rats administered massive doses of penicillin preparations]

Activity of lysozyme in the blood serum and leucocytes was determined. The experiments were carried out on albino unbred rats weighing 170 to 200 gm. Benzylpenicillin and oxacillin were administered intramuscularly in doses of 500000 Units/kg or 20000 gamma/kg once every 24 hours for 2, 4 and 6 days. The activity of lysozyme was determined by the turbidimetric and agar-diffusion methods. It was found that the activity of lysozyme in the leucocytes increased by the 5th day accompanied by a simultaneous decrease in its level in the serum followed by reaching the initial values. The data are indicative of the fact that the use of antibiotics in mega-doses is not contraindicated from the point of view of their effect on lysozyme activity.