Estimation of the Fragmentation Effect in the Registration of Superheavy Nuclei of Galactic Cosmic Rays in Pallasites

Journal of Experimental and Theoretical Physics - We report on the results of model calculations for estimating the fragmentation effect in the registration of heavy and superheavy nuclei of...     

Muography of Large Natural and Industrial Objects

Physics of Atomic Nuclei -     

Tissue-specific and neural activity-regulated expression of human BDNF gene in BAC transgenic mice

Background  

Brain-derived neurotrophic factor (BDNF) is a small secreted protein that has important roles in the developing and adult nervous system. Altered expression or changes in the regulation of the BDNF gene have been implicated in a variety of human nervous system disorders. Although regulation of the rodent BDNF gene has been extensively investigated, in vivo studies regarding the human BDNF gene are largely limited to postmortem analysis. Bacterial artificial chromosome (BAC) transgenic mice harboring the human BDNF gene and its regulatory flanking sequences constitute a useful tool for studying human BDNF gene regulation and for identification of therapeutic compounds modulating BDNF expression.     

Experimental determination of human erythrocyte membrane permeability coefficients for a series of amides

Erythrocyte membrane permeability coefficients have been determined for a series of amides by a method based on the physical and mathematical modelling of hypotonic haemolysis process. The results show that penetration of the substances occurs by two alternative ways through aqueous pores formed by proteins and by the direct dissolving of the molecules in membrane lipids. This conclusion can be confirmed by the correlation analysis between permeability coefficients of native erythrocytes and those pre-incubated with the monosodium salt of p-chloromercuribenzenesulfonic acid (pCMBS), and the partition coefficients of the substances in hydrophilic-hydrophobic phases. Penetration of substances through hydrophilic channels is limited by the sterical factor and diameter in particular. Permeability coefficients for erythrocytes pre-incubated with pCMBS increase in an accordance with the rise of the partition coefficients with correlation coefficient of 0.94, thereby indicating a lipid route of permeation of molecules through erythrocyte membranes.     

Radiocaesium pollution of fly agaric Amanita muscaria in fruiting bodies decreases with developmental stage

Amanita muscaria collected from a forested area in northern Poland in 2015 were analysed for activity concentrations of ¹³⁷Cs and ⁴⁰K. Total K concentration values were calculated from ⁴⁰K data. Mushrooms were grouped in six fruiting bodies size classes regarding to their developmental stage. The ¹³⁷Cs activity concentrations declined in A. muscaria as the fruiting bodies maturated. The contents of ⁴⁰K/K activity remained constant in caps at different developmental stage, while for stipes an increase was around twofold (⁴⁰K from 925?±?55 Bq kg^?1 dry biomass in the baby individuals and 1600?±?63–1700?±?53 Bq kg^?1 dry biomass in two oldest classes). A. muscaria is a weak accumulator of ¹³⁷Cs, while a steep drop in activity concentrations of this nuclide in the fruiting bodies as they maturate has not been reported earlier for mushrooms. Clearly, a fate of ¹³⁷Cs in A. muscaria is highly different from that of ⁴⁰K/K that is an essential element to fungi. In parallel, an observed increase in the content of ⁴⁰K/K in stipes of fruiting bodies with developmental state can be related to its ‘hardening’ and more fibrous nature with age and basic function to support the cap, but this has not been studied.     

Tagging system for almost-real photons at VEPP-3 storage ring

At BINP the construction of the tagging system for almost-real photons (TS) is in progress. The energy of tagging photons can be up to 1.5 GeV. The projected energy resolution of TS is better then 1%. For at least a half of photons the linear polarization can be determined. The tagging system will extend the possibilities for photoreaction studying at VEPP-3 significantly. TS would allow to perform a complete kinematics reconstruction, thus permitting a reliable rejection of the background processes; to extend the measurements to higher photon energy; to enabling Σ-asymmetry measurements and double polarization experiments.     

ZnS(Ag)/<Superscript>6</Superscript>LiF and LiI(Eu) scintillators and silicon photomultipliers for thermal neutron detectors with high space and time resolution

ZnS(Ag)/⁶LiF and LiI(Eu) scintillators for thermal neutron detectors have been investigated and neutron detectors based on these scintillators and photomultipliers have been tested. The efficiencies of these detectors are 5 and 66%, respectively. The possibility of developing position-sensitive detectors of thermal neutrons with high space and time resolution is discussed.