Soft Neutron Production in DIS: a Window to the Final State Interactions

Recently E-665 reported the first measurement of soft ($E_n \le 10$MeV) neutron production in deep inelastic scattering (DIS) off nuclei. We report the first theoretical analysis of the data. We find that the observed cross section can be quantitatively explained as due to the final state interactions (FSI) of low energy nucleons ($E_N \sim 200-400 MeV$) produced in the elementary $\mu N$ interactions. We argue that the data indicate strong a suppression of the FSI's of fast partons (hadrons) in DIS at high energies, and that studies of the soft neutron production would provide a new sensitive probe of the dynamics of FSI's in DIS both at fixed target energies and at the HERA $eA$ collider.Comment: 14 pages, 4 figure

Search of new pharmaceuticals on the basis of darbepoetin in the treatment of ischemic stroke: review of literature

The article contains the analysis of medical and biological publications from the global database created by the National Centre for Biology Information (NCBI), an intramural biotechnological division of the US National Library of Medicine. The authors have analyzed publications of the recent ten years. Major results of study of erythropoietins and their recombinant analogues have been generalized and systematized. There has been revealed the significant potential of the preparations of this group to be studied and used. Major advantages and drawbacks of erythropoietins and their recombinant analogues have been describe

Quinoidal Azaacenes: 99 % Diradical Character

Quinoidal azaacenes with almost pure diradical character (y=0.95 to y=0.99) were synthesized. All compounds exhibit paramagnetic behavior investigated by EPR and NMR spectroscopy, and SQUID measurements, revealing thermally populated triplet states with an extremely low-energy gap ΔEST′ of 0.58 to 1.0 kcal mol−1. The species are persistent in solution (half-life≈14–21 h) and in the solid state they are stable for weeks

The Physics of Ultraperipheral Collisions at the LHC

We discuss the physics of large impact parameter interactions at the LHC: ultraperipheral collisions (UPCs). The dominant processes in UPCs are photon-nucleon (nucleus) interactions. The current LHC detector configurations can explore small $x$ hard phenomena with nuclei and nucleons at photon-nucleon center-of-mass energies above 1 TeV, extending the $x$ range of HERA by a factor of ten. In particular, it will be possible to probe diffractive and inclusive parton densities in nuclei using several processes. The interaction of small dipoles with protons and nuclei can be investigated in elastic and quasi-elastic $J/\psi$ and $\Upsilon$ production as well as in high $t$ $\rho^0$ production accompanied by a rapidity gap. Several of these phenomena provide clean signatures of the onset of the new high gluon density QCD regime. The LHC is in the kinematic range where nonlinear effects are several times larger than at HERA. Two-photon processes in UPCs are also studied. In addition, while UPCs play a role in limiting the maximum beam luminosity, they can also be used a luminosity monitor by measuring mutual electromagnetic dissociation of the beam nuclei. We also review similar studies at HERA and RHIC as well as describe the potential use of the LHC detectors for UPC measurements.Comment: 229 Pages, 121 figure

Radial distribution of the inner magnetosphere plasma pressure using low-altitude satellite data during geomagnetic storm: the March 1-8, 1982 Event

Plasma pressure distribution in the inner magnetosphere is one of the key parameters for understanding the main magnetospheric processes including geomagnetic storms and substorms. However, the pressure profiles obtained from in-situ particle measurements by the high-altitude satellites do not allow tracking the pressure variations related to the storms and substorms, because a time interval needed to do this generally exceeds the characteristic times of them. On contrary, fast movement of low-altitude satellites makes it possible to retrieve quasi-instantaneous profiles of plasma pressure along the satellite trajectory, using the fluxes of precipitating particles. For this study, we used the Aureol-3 satellite data for plasma pressure estimation, and the IGRF, Tsyganenko 2001 and Tsyganenko 2004 storm time geomagnetic field models for the pressure mapping into the equatorial plane. It was found that during quiet geomagnetic condition the radial pressure profiles obtained coincide with the profiles, obtained previously from the high-altitude measurements. On the contrary, it was found that during geomagnetic storm the plasma pressure profiles became sharper; the position of the maximum of plasma pressure corresponds to expected one for given Dst minimum; the maximum value of inner magnetosphere static pressure correlates with the solar wind dynamic pressure. Increase in the plasma pressure profiles indicates the possibility to consider the interchange instability as one of important factors for the development of the main phase of geomagnetic storm.Comment: Accepted in Advances in Space Researc

Синтез и свойства сополимеров винилбензилового спирта со стиролом

Objectives. Synthesis and study of the properties of copolymers of vinyl benzyl alcohol (VBA) with styrene with antimicrobial properties.Methods. The study employed infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy, thin-layer chromatography, viscometry, and elemental analysis. The sessile drop method and the pencil method were respectively utilized to determine the contact angles and hardness of the films. The process of testing the film coatings’ resistance to the effects of molds consisted of contaminating the film coatings applied to the glass with mold spores of the All-Russian Collection of Microorganisms in a solution of mineral salts without sugar (Czapek–Dox medium).Results. Homopolymers of vinyl benzyl acetate and its copolymers with styrene were synthesized in this study. Homo- and copolymers of VBA were obtained by saponification. IR and proton NMR (1H NMR) spectroscopy determined the composition of the copolymers. Employing IR spectroscopy, the degree of saponification was monitored by the appearance of the hydroxyl group absorption band and the disappearance of the ester group absorption band. According to the IR spectroscopy data, only an insignificant (~3%) amount of ester groups remains in the saponified copolymers. The influence of the copolymers’ composition on their solubility in various solvents is demonstrated. IR spectroscopy of the copolymers revealed hydrogen-bond formation between the unreacted ester groups and hydroxyl groups formed due to the saponification. The viscometry of the solutions of mixtures of saponified and unsaponified copolymers, solutions of mixtures of saponified copolymer with polyvinyl acetate, and viscometry of saponified copolymers in various solvents all support this conclusion. These bonds’ concentration depends on the copolymer’s composition and can be controlled by the nature of the solvent from which these copolymers’ films are formed. Saponified copolymer solutions form smooth, transparent film coatings with excellent adhesion to metals and silicate glass surfaces. The contact angle of these films, like the hardness, decreases as the VBA units’ concentration in the copolymers increases and depends on the solvent polarity used to form the films. It has been demonstrated that increasing the VBA units concentration suppresses the microorganisms’ growth.Conclusions. Film coatings made of copolymers of styrene with VBA have been shown to have high biocidal activity against molds; can be used to protect structural materials and products from the effects of microorganisms.Цели. Синтез и изучение свойств сополимеров винилбензилового спирта (ВБС) со стиролом, обладающих антимикробными свойствами.Методы. В работе использованы такие методы как ИК- и ЯМР-спектроскопия, тонкослойная хроматография, вискозиметрия и элементный анализ. Краевые углы смачивания и твердость пленок определяли методом сидячей капли и «методом карандаша», соответственно. Метод испытаний стойкости пленочных покрытий к воздействию плесневых грибов заключался в заражении пленочных покрытий, нанесенных на стекла, спорами плесневых грибов Всероссийской коллекции микроорганизмов в растворе минеральных солей без сахара (среда Чапека-Докса).Результаты. В работе синтезированы гомополимеры винилбензилацетата и его сополимеры со стиролом. Их омылением получены гомо- и сополимеры ВБС. Состав сополимеров определен ИК- и 1H ЯМР-спектроскопией. Степень омыления контролировали ИК-спектроскопией по появлению полосы поглощения гидроксильной группы и исчезновению полосы поглощения сложноэфирной группы. По данным ИК-спектроскопии в омыленных сополимерах остается лишь незначительное (~3%) количество сложноэфирных групп. Показано влияние состава сополимеров на их растворимость в растворителях различной природы. ИК-спектроскопией сополимеров показано образование водородных связей между непрореагировавшими сложноэфирными группами и образовавшимися в результате омыления гидроксильными группами. Этот вывод подтвержден вискозиметрией растворов смесей омыленного и неомыленного сополимеров, растворов смесей омыленного сополимера с поливинилацетатом и вискозиметрией омыленных сополимеров в растворителях различной природы. Концентрация этих связей зависит от состава сополимера и может регулироваться природой растворителя, из которого формируются пленки этих сополимеров. Из растворов омыленных сополимеров формируются гладкие прозрачные пленочные покрытия с высокой адгезией к поверхностям металлов и силикатного стекла. Краевой угол смачивания этих пленок, как и твердость, уменьшается с увеличением концентрации в сополимерах звеньев ВБС и зависит от полярности растворителя, из раствора в котором сформированы пленки. Показано, что увеличение концентрации звеньев ВБС приводит к подавлению роста микроорганизмов.Выводы. Показано, что пленочные покрытия из сополимеров стирола с ВБС обладают высокой биоцидной активностью по отношению к плесневым грибам и могут быть использованы для защиты конструкционных материалов и изделий из них от воздействия микроорганизмов

Time- and dose dependent actions of cardiotonic steroids on transcriptome and intracellular content of Na+ and K+: a comparative analysis

Recent studies demonstrated that in addition to Na+,K+-ATPase inhibition cardiotonic steroids (CTSs) affect diverse intracellular signaling pathways. This study examines the relative impact of [Na+]i/[K+]i-mediated and -independent signaling in transcriptomic changes triggered by the endogenous CTSs ouabain and marinobufagenin (MBG) in human umbilical vein endothelial cells (HUVEC). We noted that prolongation of incubation increased the apparent affinity for ouabain estimated by the loss of [K+]i and gain of [Na+]i. Six hour exposure of HUVEC to 100 and 3,000 nM ouabain resulted in elevation of the [Na+]i/[K+]i ratio by ~15 and 80-fold and differential expression of 258 and 2185 transcripts, respectively. Neither [Na+]i/[K+]i ratio nor transcriptome were affected by 6-h incubation with 30 nM ouabain. The 96-h incubation with 3 nM ouabain or 30 nM MBG elevated the [Na+]i/[K+]i ratio by ~14 and 3-fold and led to differential expression of 880 and 484 transcripts, respectively. These parameters were not changed after 96-h incubation with 1 nM ouabain or 10 nM MBG. Thus, our results demonstrate that elevation of the [Na+]i/[K+]i ratio is an obligatory step for transcriptomic changes evoked by CTS in HUVEC. The molecular origin of upstream [Na+]i/[K+]i sensors involved in transcription regulation should be identified in forthcoming studies

Deoxygenation affects composition of membrane-bound proteins in human erythrocytes

Background/Aims: ATP release from erythrocyte plays a key role in hypoxia-induced elevation of blood flow in systematic circulation. We have previously shown that hemolysis contributes to erythrocyte ATP release triggered by several stimuli, including hypoxia, but the molecular mechanisms of hypoxia-increased membrane fragility remain unknown. Methods: In this study, we compared the action of hypoxia on hemolysis, ATP release and the composition of membrane-bound proteins in human erythrocytes. Results: Twenty minutes incubation of human erythrocytes in the oxygen-free environment increased the content of extracellular hemoglobin by ∼1.5 fold. Paired measurements of hemoglobin and ATP content in the same samples, showed a positive correlation between hemolysis and ATP release. Comparative analysis of SDS-PAGE electrophoresis of erythrocyte ghosts obtained under control and deoxygenated conditions revealed a ∼2-fold elevation of the content of membrane-bound protein with Mr of ∼60 kDa. Conclusion: Deoxygenation of human erythrocytes affects composition of membrane-bound proteins. Additional experiments should be performed to identify the molecular origin of 60 kDa protein and its role in the attenuation of erythrocyte integrity and ATP release in hypoxic conditions