Various physico-chemical properties of the amylolytic complex from Bacillus mesentericus]

Some physico-chemical properties of the Bacillus mesentericus amylolytic complex were studied, and optimal conditions of starch hydrolysis (pH 7.5-8.0; 45 degrees C) were found. The half-life of amylases at 50 degrees was 75 min. The heat stability of the enzymes increased in the presence of Ca2+ ions. Amylase was stable at pH 7-9 and readily inactivated at pH below 6.0. By physical and chemical characteristics the complex was close to analogous preparations from Bacillus alkalophilic strains. Isoelectrofocusing revealed that the complex consisted at least of two amylolytic enzymes.     

Genetic aspects of sexual behavior in malaria mosquitoes on the basis of specific acoustic signals at mating

Acoustic characteristics were studied in two species of the "Anopheles maculipennis" species complex, A. messeae and A. atroparvus. The species were found to clearly differ in sound frequencies, which was assumed to play a key role in species identification during mating in regions of their sympatric distribution. The sound spectrum in A. messeae was far more diverse than in A. atroparvus, which was associated with intraspecific inversion polymorphism of the former. Mosquitoes with the inversion combinations that were most common in populations of the central region of the A. messeae species area specifically differed in acoustic signal spectrum from each other. Hence, sound communication within the species was considered to be the main mechanism that is responsible for sexual partner selection and determines the chromosome associations observed earlier in individual karyotypes. Since males carrying different inversion combinations significantly differed in acoustic characteristics, females were assumed to play a main role in selecting the sexual partner.     

Temperature Dependence of Photoluminescence from Silver Nanoparticles

Strong temperature dependence of surface plasmon enhanced photoluminescence from silver nanoparticles embedded in a silica host matrix has been observed. The quantum yield of photoluminescence increases as the temperature decreases. Such an effect has been rationalized as being the result of an increase in the plasmonic enhancement factor as a consequence of the decrease in the plasmon damping constant. The decrease in the damping constant is due to a reduction in the electron–phonon scattering rate with the decrease in temperature. The temperature dependence of the photoluminescence quantum yield is stronger for small nanoparticles which reflects the strengthening of electron–phonon coupling in silver nanoparticles with a decrease of their size.     

Cytogenetic analysis of the species composition and inversion structure of populations of malarial mosquitoes in the Astrakhan region

A cytogenetic analysis of Anopheles mosquitoes in the Astrakhan region was carried out. Three species of Anopheles were identified. An. messeae lives everywhere and prevails in all of the areas of research, An. hyrcanus is found in the southwest of the region, and An. maculipennis in the northern part of the region. The populations of An. messeae show a high level of inversion polymorphism for the sex chromosome and the third autosome. A clear clinal trend of an increase in chromosomal rearrangements XL1, 3R1, and 3L1 and a decrease in the frequency of evolutionary source alternatives was revealed in laraval hemipopulations of the species from south to north.     

Work Function Evolution in Li Anode Processing

Toward improved understanding and control of the interactions of Li metal anodes with their processing environments, a combined X‐ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) characterization of the effects that O₂, CO₂, and N₂, the main gases in dry‐atmosphere battery production lines, induced on a reproducibly clean Li surface at room temperature is presented here. XPS measurements demonstrate that O₂ is ten times more effective than CO₂ at oxidizing metal Li. Notably, pure N₂ is shown to not dissociate on clean metal Li. UPS results indicate that decomposition of O₂ (CO₂) reduces the work function of the Li surface by almost 1 eV, therefore increasing the reduction energy drive for the treated substrate by comparison to bare metallic Li. DFT simulations semiquantitatively account for these results on the basis of the effects of dissociative gas adsorption on the surface dipole density of the Li surface.     

Laser-Driven Hybridization of a Surface Plasmon Resonance Collective Mode in a Monolayer of Silver Nanoparticles

Plasmonics - Laser-driven hybridization of a collective surface plasmon mode of a monolayer of silver nanoparticles has been studied as a function of irradiation power density. Two collective...     

Competitive relations between tetanus anatoxin and toxin]

Experiments were conducted on albino mice; it was shown that preliminary injection of tetanus toxoid enhanced the animal resistance to tetanus toxin, this being expressed in increase in LD50. The effect increased the higher doses of the toxoid and their fractional injection. By using protagon and crude mitochondrial fraction isolated from the brain as a receptor of tetanus toxin in the nervous tissue there were established competitive relations for the receptor between the tetanus toxoid and the toxin. The results of investigations confirmed the authors' earlier statement that the molecule of the tetanus toxin contained different functional groups responsible for the toxin binding with the receptor in the nervous tissue, for the pathogenic action of the toxin and for the binding of the toxin with antitoxin.