On the influence of motion of the medium on the photophoresis of a spheroidal solid aerosol particle

This paper considers the influence of motion of the medium (account of convective terms in the heat conduction equations) on the photophoresis of a large aerosol spheroidal particle at small relative temperature drops in its vicinity. It has been shown that at a fixed ratio of semiaxes with increasing intensity of the incident radiation the total contribution of the medium motion leads to a monotonic decrease in the rate of photophoresis, whose degree depends on the equatorial radius of the spheroidyesBelgorod State Universit

Plasma hardening of medium carbon steels

The structure, size and hardness of the zone of hardening of pre-annealed steels (30XHMA, 34XH1M, 35XH2Φ, 38XΓH, 40XHMA, 40XH2MA, 45) was studied after treatment with a plasma arc of direct polarity. It was shown that plasma hardening forms a thin layer of martensitic-austenitic structure with variable composition and hardness on the treated steel surface. The zone subjected to hardening was represented by marten site of different dispersion and ferrite veins. Between the quenching zone and the base metal there was a transition zone with a gradient structure of plate perlite and elements of perlite-ferrite base, the share of which was gradually increasing. The structural-phase structure of this zone provided a smooth transition of mechanical properties from the hardened layer to the base metal. Dependences for management of a structural condition, hardness and depth of a zone of hardening were determined. © 2019 Published under licence by IOP Publishing Ltd

Proposal for a Listening Comprehension Oriented Classroom -With focus on interpretation practise-

© 2016 American Chemical Society.Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, -40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like phosphoranes with phosphorus-carbon and phosphorus-oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane

Желчнокаменная болезнь среди медицинского персонала поликлиники: факторы риска ее развития в разных профессиональных группах

The aim. Identification of risk factors for gallstone disease (GDS) development between different professional groups of polyclinic medical staff. Material and methods. 75 medical staff members were divided into two groups (1st group: 30 doctors; 2nd group: 45 nurses). All of them were interviewed fo r information about profession, gender, age, waist circumference (WC), body mass index (BMI), smoking, arterial hypertension (AH), diabetes mellitus (DM) and hypercholesterolemia. In addition, women were interviewed about the number of pregnancies, ostmenopause and taking oral contraceptive pills (OCPs). To assess physical activity, a short international questionnaire on physical activity (IPAQ) was used. To identify the presence of professional burnout (PB) syndrome we applied the Maslach Burnout Inventory (MBI) questionnaire, adapted by N.Е. Vodopianova for medical staff. At the final stage, the data of abdominal organs ultrasound examination were analyzed based on the materials of medical staff outpatient records. Results. The GSD prevalence among doctors was 33.3%, and 24.4% among nurses. In both groups age, AH, weight, WC and BMI contribute to GSD formation. In the first group of individuals with GSD, the level of total cholesterol (TC) was significantly higher. In the same group extremely high PB, postmenopause (p <0.05) and hypodynamia (p <0.1) were much more common. In the second group, there were more DM cases and pregnancies (p <0.05). Conclusion. The medical staff of the clinic has a high GSD incidence, whose frequency depends not only on classical risk factors prevalence, but is also determined by profession peculiarities, characterized by high psychological stress and lower physical activity of physicians, compared to nurses.Цель исследования. Выявить факторы риска развития желчнокаменной болезни (ЖКБ) среди медицинского персонала поликлиники в разных профессиональных группах. Материалы и методы. В поликлинике было осмотрено и анкетировано 75 медицинских сотрудников поликлиники, которые были разделены на две группы. В 1-ю были включены 30 врачей; во 2-ю - 45 медицинских сестер. Анализу подвергались такие показатели, как профессия, пол, возраст, объем талии (ОТ), индекс массы тела (ИМТ), курение, наличие артериальной гипертензии (АГ), сахарного диабета (СД), гиперхолестеринемии, постменопаузы; у женщин – количество беременностей и прием оральных контрацептивов (ОК). Для оценки физической активности применяли краткий международный опросник по физической активности (IPAQ). Для выявления симптомов профессионального выгорания (ПВ) использовали опросник Maslach Burnout Inventory (MBI), адаптированный Н.Е. Водопьяновой для медицинских сотрудников. На конечном этапе анализировались данные ультразвукового исследования органов брюшной полости по амбулаторным картам медицинских работников. Результаты. Распространенность ЖКБ среди врачей составила 33,3%, и 24,4% среди медицинских сестер. В обеих группах на формирование ЖКБ влияют возраст, наличие АГ, вес, ОТ, ИМТ. В первой группе лиц с ЖКБ уровень общего холестерина был достоверно выше (ОХ). В этой же группе ПВ крайне высокой степени, постменопауза (p<0,05) и гиподинамия (p<0,1) встречались значительно чаще. В группе медицинских сестер с ЖКБ отмечалось преобладание лиц с СД и большее число беременностей (p<0,05). Заключение. У медицинского персонала поликлиники имеет место высокая распространенность ЖКБ, частота которой зависит не только от распространенности классических факторов риска, но и определяется особенностями профессиональной деятельности, характеризующейся высокой психологической нагрузкой и более низкой физической активностью врачебного персонала, по сравнению с медицинскими сестрами

Upper Limit on the Magnetic Dipole Contribution to the 5p-8p Transition in Rb by Use of Ultracold Atom Spectroscopy

We report on hyperfine-resolved spectroscopic measurements of the electric-dipole forbidden 5$p_{3/2} \to 8p_{1/2}$ transition in a sample of ultracold $^{87}$Rb atoms. The hyperfine selection rules enable the weak magnetic-dipole (M1) contribution to the transition strength to be distinguished from the much stronger electric-quadrupole (E2) contribution. An upper limit on the M1 transition strength is determined that is about 50 times smaller than an earlier experimental determination. We also calculate the expected value of the M1 matrix element and find that it is less than the upper limit extracted from the experiment.Comment: 7 pages, 4 figures, 3 table

Regulatory mechanisms tuning ethylen signaling in plants

Plant hormone ethylene regulates a wide range of physiological processes during plant development and coordinates different stress responses. Among others ethylene controls such practically significant characteristics of agricultural crops as fruit ripening rates and plant tolerance to stress conditions. That is why understanding molecular mechanisms underlying ethylene action is one of the basic questions in plant biology that is addressed in the context of both fundamental research and application in agriculture. Ethylene biosynthesis from methionine amino acid and the main points of its signaling pathway from membrane receptors to effector genes are studied in details and widely reviewed. Far less is known about genetic regulation of these two processes although it is the one that ensures accurate plant reaction to different endogenous and exogenous signals and causes the multiplicity of different physiological responses to ethylene. This review summarizes data about regulatory mechanisms of ethylene biosynthesis and signaling. It reports the key transcriptional and post-translational regulatory factors which control expression and stability of the main components of ethylene biosynthesis and signaling pathways, and describes multiple feed-backs supplementing the linear model of ethylene signaling. Particular attention is given to the role of hormonal crosstalk in the process. Different mechanisms of hormonal interaction are illustrated by synergy or antagonism of ethylene and auxin, jasmonates, cytokinins, brassinosteroids. Possible molecular basics of multiplicity of different physiological responses to ethylene is also discussed

Allelic polymorphism of atoxigenic Vibrio Cholerae strains of housekeeping genes isolated in Siberia and Far East

There were atoxigenic Vibrio cholerae strains housekeeping genes analyzed. There were studied 20 isolates, in which nine sequence types have determined and five of which have described as unique. There were clustersformed as belonging to serogroup: first cluster includes RO-variantstrains and one O139 serogroup strain of V. cholerae, second - all O1 serogroup V. cholerae strains. There are sequence types associated with place and time isolation strains in some cases, although differentiation of the strains, which are formed the dominant sequence type strains group have no spatial and temporal characteristics associated