Mast Cell-Derived Histamine Regulates Liver Ketogenesis via Oleoylethanolamide Signaling

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Efficiency and allometry of seed production in grassland forbs: site and year comparative study in the Italian Eastern Pre-Alps

Forbs are important biodiversity components of grasslands and are often threatened by management intensification. As most forbs propagate predominantly by seed, knowledge of their seed regenerative traits would improve the conservation and restoration of forb-rich ecosystems. The main seed production traits of six forbs that are common in European species-rich grasslands were studied by collecting fertile shoots from different sites and over several years. Among sites and years, variability was high, particularly in the number of inflorescences per shoot, which affected ovule production more than any other trait. Relationships between inflorescence size and the number of ovules were mainly negatively allometric or almost so, with lower flower densities in larger inflorescences. The average ovule-to-seed transformation efficiency was 58%. There was significant variation among collections of the same species, and even more between species. Species with a low ovule-to-seed transformation efficiency generally exhibited compensatory, high seed viability. Large inflorescences had high ovule to seed utilization values, probably because of better nutrient conditions. Seed germinability (average, 30%) was much lower than seed viability (average, 54%); therefore, seed dormancy was an important feature of the species studied.     

Mechanism of Bidirectional Leading-Strand Synthesis Establishment at Eukaryotic DNA Replication Origins

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Precise Gene Editing Preserves Hematopoietic Stem Cell Function following Transient p53-Mediated DNA Damage Response

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Can an inactivating agent increase enzyme activity in organic solvent? Effects of 18‐crown‐6 on lipase activity,enantioselectivity, and conformation

Lipase from Burkholderia cepacia (lipase BC) and lipase B from Candida antarctica (CALB) show an increase of the transesterification activity in toluene (up to 2.4- and 1.7-fold, respectively), when lyophilized with 18-crown-6. Nevertheless, the increase was observed only for low (less than 100) 18-crown-6/lipase molar ratio, while at higher ratios, the activity decreased for both enzymes to values lower than those obtained in the absence of the additive. In 1,4-dioxane, the activation is lower for lipase BC (1.7-fold) and for CALB (1.5-fold). Concerning enantioselectivity, tested in the kinetic resolution of 6-methyl-5-hepten-2-ol, only in the case of CALB, an effect of the additive (the E value varied from about 120 to 280) was observed. In water, 4% (w/w) of 18-crown-6 caused a loss of activity in the hydrolysis of p-nitrophenyl laurate of about 88 and 99.75%, compared to that observed in the absence of the crown ether for CALB and lipase BC, respectively. These data and the conformational analysis of both lipases, carried out by FT/IR spectroscopy indicate that the enzyme inactivation in water and in organic solvents at 18-crown-6/lipase molar ratios, higher than 100 might be due to conformational changes caused by the additive. Instead, at molar ratios lower than 100, 18-crown-6 might increase the activity - particularly, in toluene - thanks to the fact that in its presence, the enzyme has an hydrogen bonds pattern, more similar to that in water. This suggests that the additive would be able to provide the enzyme with more water.     

Biodeterioration of crude oil and oil derived products: a review

Biodeterioration of crude oil and oil fuels is a serious economic and an environmental problem all over the world. It is impossible to prevent penetration of microorganisms in oil and fuels both stored in tanks or in oilfields after drilling. Both aerobic and anaerobic microorganisms tend to colonise oil pipelines and oil and fuel storage installations. Complex microbial communities consisting of both hydrocarbon oxidizing microorganisms and bacteria using the metabolites of the former form an ecological niche where they thrive. The accumulation of water at the bottom of storage tanks and in oil pipelines is a primary prerequisite for development of microorganisms in fuels and oil and their subsequent biological fouling. Ability of microorganisms to grow both in a water phase and on inter-phase of water/hydrocarbon as well as the generation of products of their metabolism worsen the physical and chemical properties of oils and fuels. This activity also increases the amount of suspended solids, leads to the formation of slimes and creates a variety of operational problems. Nowadays various test-systems are utilized for microbial monitoring in crude oils and fuels; thus allowing an express determination of both the species and the quantities of microorganisms present. To suppress microbial growth in oils and fuels, both physico-mechanical and chemical methods are applied. Among chemical methods, the preference is given to substances such as biocides, additives, the anti-freezing agents etc that do not deteriorate the quality of oil and fuels and are environmentally friendly. This review is devoted to the analysis of the present knowledge in the field of microbial fouling of crude oils and oil products. The methods utilized for monitoring of microbial contamination and prevention of their undesirable activities are also evaluated. The special focus is given to Russian scientific literature devoted to crude oil and oil products biodeterioration.