Phase Diagrams of Bi1-xSbx Thin Films with Different Growth Orientations

A closed-form model is developed to evaluate the band-edge shift caused by quantum confinement for a two-dimensional non-parabolic carrier-pocket. Based on this model, the symmetries and the band-shifts of different carrier-pockets are evaluated for BiSb thin films that are grown along different crystalline axes. The phase diagrams for the BiSb thin film systems with different growth orientations are calculated and analyzed

Dependences of thermoelectric properties on the thickness of thin films of indium doped lead telluride

Dependences of thermoelectric properties (the Seebeck coefficient S, the electric conductivity σ, the Hall coefficient RH, the carrier mobilityμ and the thermoelectric power P = S²·σ) on the thickness d (d = 10 – 255 nm) of thin films prepared by vacuum evaporation of indiumdoped PbTe crystals and subsequent condensation on (111) BaF₂ substrates were obtained. With decreasing thickness of films to d ≈ 40 nm, there is n- to p-type inversion of conduction which is related to a change in thermodynamic equilibrium conditions and partial reevaporation of lead and/or indium atoms. Extremes were found on the thickness dependences of properties at d₁ ≈ 20 nm which is indicative of hole gas quantization. In the range of thicknesses with n-type conduction there is a smooth change in thermoelectric properties with thickness which testifies to manifestation of classical size effect and is sufficiently well described in the framework of the Fuchs-Sondheimer theory

Symmetries of Electrostatic Interaction between DNA Molecules

We study a model for pair interaction $U$ of DNA molecules generated by the discrete dipole moments of base-pairs and the charges of phosphate groups, and find noncommutative group of eighth order ${\cal S}$ of symmetries that leave $U$ invariant. We classify the minima using group ${\cal S}$ and employ numerical methods for finding them. The minima may correspond to several cholesteric phases, as well as phases formed by cross-like conformations of molecules at an angle close to $\rm{90}^{o}$, "snowflake phase". The results depend on the effective charge $Q$ of the phosphate group which can be modified by the polycations or the ions of metals. The snowflake phase could exist for $Q$ above the threshold $Q_C$. Below $Q_C$ there could be several cholesteric phases. Close to $Q_C$ the snowflake phase could change into the cholesteric one at constant distance between adjacent molecules.Comment: 13 pages, 4 figure

Vacuum fluctuation forces between ultra-thin films

We have investigated the role of the quantum size effects in the evaluation of the force caused by electromagnetic vacuum fluctuations between ultra-thin films, using the dielectric tensor derived from the particle in a box model. Comparison with the results obtained by adopting a continuum dielectric model shows that, for film thicknesses of 1-10 nm, the electron confinement causes changes in the force intensity with respect to the isotropic plasma model which range from 40% to few percent depending upon the film electron density and the film separation. The calculated force shows quantum size oscillations, which can be significant for film separation distances of several nanometers. The role of electron confinement in reducing the large distance Casimir force is discussed

Prediction of Anisotropic Single-Dirac-Cones in Bi1−x{}_{1-x}Sbx{}_{x} Thin Films

The electronic band structures of Bi${}_{1-x}$Sb${}_{x}$ thin films can be varied as a function of temperature, pressure, stoichiometry, film thickness and growth orientation. We here show how different anisotropic single-Dirac-cones can be constructed in a Bi${}_{1-x}$Sb${}_{x}$ thin film for different applications or research purposes. For predicting anisotropic single-Dirac-cones, we have developed an iterative-two-dimensional-two-band model to get a consistent inverse-effective-mass-tensor and band-gap, which can be used in a general two-dimensional system that has a non-parabolic dispersion relation as in a Bi${}_{1-x}$Sb${}_{x}$ thin film system

Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaboration at CERN. The following kinematic domain is covered by the data: photon virtuality $Q^{2}>1$ (GeV/$c$)$^2$, invariant mass of the hadronic system $W > 5$ GeV/$c^2$, Bjorken scaling variable in the range $0.003 < x < 0.4$, fraction of the virtual photon energy carried by the hadron in the range $0.2 < z < 0.8$, square of the hadron transverse momentum with respect to the virtual photon direction in the range 0.02 (GeV/$c)^2 < P_{\rm{hT}}^{2} < 3$ (GeV/$c$)$^2$. The multiplicities are presented as a function of $P_{\rm{hT}}^{2}$ in three-dimensional bins of $x$, $Q^2$, $z$ and compared to previous semi-inclusive measurements. We explore the small-$P_{\rm{hT}}^{2}$ region, i.e. $P_{\rm{hT}}^{2} < 1$ (GeV/$c$)$^2$, where hadron transverse momenta are expected to arise from non-perturbative effects, and also the domain of larger $P_{\rm{hT}}^{2}$, where contributions from higher-order perturbative QCD are expected to dominate. The multiplicities are fitted using a single-exponential function at small $P_{\rm{hT}}^{2}$ to study the dependence of the average transverse momentum $\langle P_{\rm{hT}}^{2}\rangle$ on $x$, $Q^2$ and $z$. The power-law behaviour of the multiplicities at large $P_{\rm{hT}}^{2}$ is investigated using various functional forms. The fits describe the data reasonably well over the full measured range.Comment: 28 pages, 20 figure

Лейкомогенный риск и темп накопления дозы радиационного воздействия. Сообщение 2: Сравнительный анализ лейкоцитарных индексов и динамики показателей периферической крови в зависимости от дозы внешнего гамма-облучения

The results of a retrospective analysis of leukocytic indices and dynamics of peripheral blood values in relation to external gamma-exposure dose among the personnel of the first atomic production facility in Russia were presented. The study was performed on the basis of the database “Leukemia in the cohort of workers of the Mayak Production Association employed in 1948-1958”. The database contains hematological, clinical and dosimetry information on the two groups of workers: the study group includes individuals with leukemia as the cause of death (n=84); control group includes personnel without hematological cancer pathology (n=300). The control group was composed by selecting 3-4 internal control cases for each leukemia case taking into account gender, age of the start of the exposure and the same accumulated absorbed dose of gamma-exposure to red bone marrow. Based on 19592 analysis of peripheral blood we had described hematopoiesis shifts along cell lines, performed correlation analysis of interrelation between hemogram values and radiation dose, analyzed particular characteristics of blast cells’ appearance in peripheral blood flow in the period prior to leukemias. Comparative analysis of various leukocytic indices was performed among Mayak PA personnel for the first time. The diverse nature of the response of bone marrow hematopoiesis was noted; more pronounced hematological shifts were indicated regarding more intensive production exposure. A number of hematopoietic features were detected among people exposed to production radiation: 1) cytopenia in relation to minimum accumulated doses of radiation exposure in both studied groups; 2) more pronounced lability of hemograms in relation to increased accumulation dose of external gamma-exposure and period of radiation exposure among individuals who had developed leukemia in future in comparison to controls; 3) correlation between peripheral blood cells and accumulated doses of external gamma-exposure was characterized by the highest values of coefficients among individuals with future leukemias; 4) myeloblasts were most often registered among all the blast cells; proerythroblasts were characterized by the shortest average period from the start of the exposure and to the moment of their appearance in the peripheral blood flow (178 days in the study group); polychromatophile erythroblasts in peripheral blood were registered only among the workers with future leukemia; 5) when comparing leukocytic indices in proportion to the categories of accumulated doses of external gamma-exposure, a pronounced variability in the ratio of blood cells was observed among exposed individuals who were subsequently diagnosed with leukemia, especially in the range of 2.0-2.5 Gy. Thus, a comprehensive analysis of hematological parameters, including the assessment of leukocytic indices, is more informative than studying a standard hemogram. Particular features of the dynamics of the cellular composition of peripheral blood can be used as indicators of pathological hematopoiesis in exposed workers prior to clinical manifestation of leukemia.Представлены результаты ретроспективного анализа лейкоцитарных индексов и динамики показателей периферической крови в зависимости от дозы внешнего гамма-облучения среди персонала первого в стране предприятия атомной отрасли. Исследование проведено на основе базы данных «Лейкозы в когорте персонала производственного объединения «Маяк» 1948–1958 гг. найма». База данных включает гематологическую, клиническую и дозиметрическую информацию о двух группах работников предприятия: в основную группу вошли лица, причиной смерти которых был лейкоз (n=84); в группу сравнения – персонал без онкогематологической патологии (n=300). Формирование группы сравнения произведено подбором 3–4 внутренних контролей к каждому случаю лейкоза с учетом пола, возраста начала облучения и той же накопленной поглощенной дозы внешнего гамма-облучения на красный костный мозг. На основе 19 592 анализов периферической крови описаны сдвиги гемопоэза по клеточным линиям, проведен корреляционный анализ взаимосвязи между показателями гемограммы и дозой радиационного воздействия, проанализированы особенности появления в периферическом кровотоке бластных клеток в период, предшествующий лейкозам. Впервые среди персонала «Маяка» проведен сравнительный анализ различных лейкоцитарных индексов. Отмечен разноплановый характер реагирования костномозгового кроветворения, показаны более выраженные гематологические сдвиги при более интенсивном производственном облучении. Выявлен ряд особенностей гемопоэза среди облученных на производстве лиц: 1) цитопения при минимальных накопленных дозах радиационного воздействия в обеих исследуемых группах; 2) более выраженная лабильность гемограмм с увеличением накопленной дозы внешнего гамма-облучения и периода радиационного воздействия среди лиц, заболевших в дальнейшем лейкозами, по сравнению с контролем; 3) корреляционная взаимосвязь между клетками периферической крови и накопленными дозами внешнего гамма-облучения характеризовалась наибольшими значениями коэффициентов среди лиц с последующими лейкемиями; 4) среди бластных клеток наиболее часто регистрировались миелобласты; проэритробласты характеризовались самым коротким средним периодом от момента начала облучения до их появления в периферическом кровотоке (в основной группе – 178 дней); полихроматофильные эритробласты в периферической крови были зарегистрированы только среди персонала с лейкемиями в дальнейшем; 5) при сравнении лейкоцитарных индексов пропорционально категориям накопленных доз внешнего гамма-облучения отмечена выраженная вариабельность соотношения клеток крови среди облученных лиц, у которых впоследствии диагностирован лейкоз, особенно в диапазоне 2,0–2,5 Гр. Таким образом, комплексный анализ гематологических показателей, включая оценку лейкоцитарных индексов, является более информативным, чем изучение обычной гемограммы. Особенности динамики клеточного состава периферической крови могут служить индикаторами патологического кроветворения у облученных работников до клинической манифестации лейкемий

Light isovector resonances in π-p →π-π-π+p at 190 GeV/c

We have performed the most comprehensive resonance-model fit of π-π-π+ states using the results of our previously published partial-wave analysis (PWA) of a large data set of diffractive-dissociation events from the reaction π-+p→π-π-π++precoil with a 190 GeV/c pion beam. The PWA results, which were obtained in 100 bins of three-pion mass, 0.5<2.5 GeV/c2, and simultaneously in 11 bins of the reduced four-momentum transfer squared, 0.1<1.0 (GeV/c)2, are subjected to a resonance-model fit using Breit-Wigner amplitudes to simultaneously describe a subset of 14 selected waves using 11 isovector light-meson states with JPC=0-+, 1++, 2++, 2-+, 4++, and spin-exotic 1-+ quantum numbers. The model contains the well-known resonances π(1800), a1(1260), a2(1320), π2(1670), π2(1880), and a4(2040). In addition, it includes the disputed π1(1600), the excited states a1(1640), a2(1700), and π2(2005), as well as the resonancelike a1(1420). We measure the resonance parameters mass and width of these objects by combining the information from the PWA results obtained in the 11 t′ bins. We extract the relative branching fractions of the ρ(770)π and f2(1270)π decays of a2(1320) and a4(2040), where the former one is measured for the first time. In a novel approach, we extract the t′ dependence of the intensity of the resonances and of their phases. The t′ dependence of the intensities of most resonances differs distinctly from the t′ dependence of the nonresonant components. For the first time, we determine the t′ dependence of the phases of the production amplitudes and confirm that the production mechanism of the Pomeron exchange is common to all resonances. We have performed extensive systematic studies on the model dependence and correlations of the measured physical parameters

Corrigendum to "Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section" [Phys. Lett. B 793 (2019) 188]

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Инвазивный микоз с поражением центральной нервной системы, обусловленный редкими дрожжевыми грибами Malassezia spp., у пациентов с острым лейкозом: описание клинических случаев и обзор литературы

Malassezia spp. is a commensal yeast that represents normal microflora in humans and some animals. However, Malassezia spp. can cause life-threatening invasive mycosis. Evidence on Malassezia spp. infections is limited mostly to a case reports describing disease in newborns and premature infants, because lipid infusions (total parenteral nutrition) given through central venous catheter is a major risk factor. Here, we report two cases of CNS infection caused by Malassezia species in non-neonates with acute leukemia.Malassezia spp. — дрожжевые грибы, которые представлены в составе нормальной микрофлоры кожи человека и как симбионт препятствуют развитию инфекций, обусловленных опасными патогенами. Однако Malassezia spp. также может стать причиной тяжелого инвазивного микоза и привести к летальному исходу. Данные литературы ограничены, представлены преимущественно публикациями об инфекциях у новорожденных и недоношенных детей, что, в первую очередь, связывают с известным фактором риска — применение парентерального питания, включающего в себя жировую эмульсию, с использованием центрального венозного катетера. Мы представляем клинические случаи инфекции центральной нервной системы, обусловленной редкими возбудителями, дрожжевыми грибами рода Malassezia, у детей с острым лейкозом