Activation of formylmethanofuran synthesis in cell extracts of Methanobacterium thermoautotrophicum.

In cell extracts of Methanobacterium thermoautotrophicum, formylmethanofuran (formyl-MFR) synthesis (an essential CO2 fixation reaction that is an early step in CO2 reduction to methane) is subject to a complex activation that involves a heterodisulfide of coenzyme M and N-(7-mercaptoheptanoyl)threonine O3-phosphate (CoM-S-S-HTP). In this paper we report that titanium(III) citrate, a low-potential reducing agent, stimulated CO2 reduction to methane and activated formyl-MFR synthesis in cell extracts. Titanium(III) citrate functioned as the sole source of electrons for formyl-MFR synthesis and enabled this reaction to occur independently of CoM-S-S-HTP. In addition, CoM-S-S-HTP was found to activate an unknown electron carrier that reduced metronidazole. The activation of formyl-MFR synthesis by CoM-S-S-HTP may involve the activation of a low-potential electron carrier.     

Eosinophils preferentially use bromide to generate halogenating agents

Human eosinophils preferentially utilize bromide to generate a brominating agent, even at physiological halide concentrations, where chloride (140 mM) is over 1000-fold greater than bromide (20-100 microM). Under the same conditions, neutrophils use chloride to generate a chlorinating agent. The total amount of active halogen trapped by 1,3,5-trimethoxybenzene from eosinophils increases by over 2-fold as the added bromide concentration increases from 0 to 100 microM, with approximately 40 nmol of halogen trapped per million cells at the highest bromide level. At least 25-35% of the oxygen consumed by stimulated eosinophils is directed toward the generation of halogenating species. Since the relative halogenating behavior of eosinophil peroxidase and neutrophil myeloperoxidase in this bromide range is essentially identical to that of the cells, the specificity of eosinophils toward bromide is intrinsic to eosinophil peroxidase and not to any special cellular properties. These results suggest that human eosinophils use bromide in vivo and that a deficiency of bromide may influence their ability to produce halogenating agents.     

Uracil-DNA glycosylase in insects. Drosophila and the locust

It has been reported that Drosophila lacks a uracil-DNA glycosylase but that a direct incising activity on uracil-containing DNA appeared developmentally only in third instar larvae. In contrast we have found by two independent assays, that uracil-DNA glycosylase exists in both Drosophila eggs as well as in third instar larvae. The first assay shows the liberation of [3H] uracil from a d(AT)n polymer randomly substituted with [3H]uracil by its synthesis in the presence of [3H] dUTP. The second fluorometric assay for uracil-DNA glycosylase depends on the unique topological properties of circular DNAs and has the advantage of detecting apyrimidinic/apurinic (AP) endonuclease activity as well. To test one other insect, locust eggs were also assayed for uracil-DNA glycosylase. The amount of uracil-DNA glycosylase correlated well with the amount of DNA in actively replicating cells.     

Medical Materials Based on Chitosan Succinamide–Glycerol Systems

The conditions to obtain materials with elastic-viscous properties based on chitosan succinamide have been studied. A decreased polymer content and a transition from visco-elastic liquids to elastic-viscous systems were shown upon the addition of glycerol to an aqueous solution of chitosan succinamide. The systemic response, biological compatibility, and dynamics of bioresorbability of the obtained materials were studied during implantation in laboratory animals.     

EEG Spectral Analysis on OM Mantra Meditation: A Pilot Study

Mantra meditation is easy to practice. “OM” Mantra is the highest sacred symbol in Hinduism. The present study investigated the temporal dynamics of oscillatory changes after OM mantra meditation. Twenty-three naive meditators were asked to perform loud OM chanting for 30 min and the EEG were subsequently recorded with closed eyes before and after it. To obtain new insights into the nature of the EEG after OM chanting, EEG signals were analyzed using spectral domain analysis. Statistical analysis was performed using repeated measures of analysis of variance. It did not reveal any specific band involvement into OM mantra meditation. But significantly increase in theta power was found after meditation when averaged across all brain regions. This is the main effect of OM mantra meditation. However, the theta power showed higher theta amplitude after condition at all regions in comparison to the before condition of meditation. Finding was similar to other studies documenting reduction in cortical arousal during a state of relaxation. The study argues for the potential role of loud ‘OM’ chanting in offering relaxation. It provides a new perspective of meditation to the naive meditators. This information may help to demystify meditation and encourage those considering this as beneficial practice.     

Experimental Study of the Effect of External Inductance on Pinch Characteristics and Neon Soft X-Ray Yield in Filippov-Type Plasma Focus Device

Plasma Physics Reports - So far, the detailed experimental effect of the inductance on the X-ray yield in the Filippov-type plasma focus devices has not been documented in literature. In this...