Electrophoretic deposition of YSZ layers on pyrolytic graphite and a porous anode substrate based on NiO-YSZ

Solid oxide fuel cells are promising hydrogen energy devices. The goal of this research was to create ceramic layers for SOFCs based on yttria-stabilized zirconia (YSZ) and to investigate their parameters. YSZ ceramic layers with a thickness of 5.14 μm on a porous NiO–YSZ substrate and 7 μm on pyrolytic graphite were obtained by electrophoretic deposition. X-ray diffraction and electron microscopy were used to determine the composition, structure, and morphological features of ceramic layers. The effects of the substrate's nature, the degree of dispersion of the initial YSZ powder, and the heat treatment conditions on the properties of the ceramic layer YSZ were considered

On Nonperturbative Calculations in Quantum Electrodynamics

A new approach to nonperturbative calculations in quantum electrodynamics is proposed. The approach is based on a regular iteration scheme for solution of Schwinger-Dyson equations for generating functional of Green functions. The approach allows one to take into account the gauge invariance conditions (Ward identities) and to perform the renormalization program. The iteration scheme can be realized in two versions. The first one ("perturbative vacuum") corresponds to chain summation in the diagram language. In this version in four-dimensional theory the non-physical singularity (Landau pole) arises which leads to the triviality of the renormalized theory. The second version ("nonperturbative vacuum") corresponds to ladder summation and permits one to make non-perturbative calculations of physical quantities in spite of the triviality problem. For chiral-symmetrical leading approximation two terms of the expansion of the first-step vertex function over photon momentum are calculated. A formula for anomalous magnetic moment is obtained. A problem of dynamical chiral symmetry breaking (DCSB) is considered, the calculations are performed for renormalized theory in Minkowsky space. In the strong coupling region DCSB-solutions arise. For the renormalized theory a DCSB-solution is also possible in the weak coupling region but with a subsidiary condition on the value of $\alpha$.Comment: 31 pages, Plain LaTex, no figures. Journal version: some discussion and refs. are adde

Features of the intestinal microbiome in patients with thyroid diseases

Introduction. Today the search and development of new methods for diagnosing organic or functional pathology of the thyroid gland with an asymptomatic or clinically nonspecific course is an urgent task of endocrinology and therapy. The functioning of the thyroid gland and the state of the human intestinal microbiome are dynamically interrelated. One of the considered promising methods is mass spectrometry of microbial markers of the human intestinal microbiota.The purpose of the study. To study the microbial spectrum and characteristics of the biotic environment of the intestine in patients with thyroid diseases.Materials and methods. 21 patients were examined (8 men and 13 women, median age 40.5 [31.75; 54] years, respectively; 15 with thyroid disease, 6 without thyroid disease). In addition to the standard clinical and laboratory-instrumental examination, patients, colon contents were examined by chromatography-mass spectrometry of microbial materials. The work used descriptive non-parametric statistics with subsequent interpretation. Mean values of indicators and their variance are presented as median, upper and lower quartiles. In relation to representatives of the fecal microbiota, in addition to absolute values, the frequency of occurrence of the microorganism within the reference range, moderate or pronounced deviations was taken into account. The determination of the statistical significance of differences in the relative frequency value was carried out using Fisher’s exact test. The presentation of the results is implemented in the form of range diagrams, compactly depicting a one-dimensional probability distribution, tables. Results. Differences in the composition of the microbiota of the control group and the experimental group for Alcaligenes spp., Staphylococcus spp., Megamonas hypermegale, Peptostreptococcus anaerobius were revealed.Conclusions. The development of thyroid gland pathology is accompanied by significant deviations in the composition of the fecal microbiota, determined by mass spectrometry of microbial markers. In persons with thyroid pathology, in the absence of clinically significant external influences on the intestinal microbiome, a pronounced decrease in the level of Alcaligenes spp., Staphylococcus spp., is detected, a tendency to a decrease in the level of Megamonas hypermegale, Peptostreptococcus anaerobius is determined. Further differentiated study of the composition of the intestinal microbiome in patients with thyroid diseases is required, depending on the nosological affiliation and the nature of the endocrine dysfunction

Features of information dissemination in the visual sensory system depending on the processes of visual perception

The goal of the research is to study the features of visual information distribution depending on the pole of cognitive style: field-dependence/ field-independence (FD/ FID

Дослідження синдрому емоційного і професійного вигорання у фармацетичних працівників

The burnout as a result of professional stress occurs when the adaptive capacity (resources) of the pharmaceutical worker in overcoming stressful situation becomes difficult, the "emotional burnout syndrome" - is the appropriate response to prolonged working stresses of employee during his professional activity. Our conducted researches in the regions of the country show that only 3-5% of pharmaceutical professionals familiar with the term "emotional burnout syndrome". So inKievto 10 per cent of people are familiar with this concept, at the same time, 54 per cent of workers aged 45-60 years old and 32 per cent aged 25-30 years old every day get into stressful situations and have different diseases, indicating the presence of the syndrome "professional burnout".Выгорание как следствие профессиональных стрессов возникает тогда, когда адаптационные возможности (ресурсы) фармацевтического работника в преодолении стрессовой ситуации становятся затруднительными, т.е. "синдром эмоционального выгорания" – это соответствующая реакция на продолжительные рабочие стрессы работника, в процессе его профессиональной деятельности. Проведенные собственные исследования в областях страны свидетельствуют, что только 3-5%  фармацевтических работников знакомы с понятием "синдром эмоционального выгорания". Так в  г. Киеве до 10% человек ознакомленным с этим понятием, в то же время 54% работников в возрасте 45-60 лет и 32% в возрасте 25-30 лет ежедневно попадают в стрессовые ситуации и имеют различные заболевания, свидетельствующие о наличии синдрома "профессионального выгорания".Вигорання як наслідок професійних стресів виникає тоді, коли адаптаційні можливості (ресурси) фармацевтичного працівника у подоланні стресової ситуації стають скрутними, тобто "синдром емоційного вигорання" - це відповідна реакція на тривалі робочі стреси працівника, в процесі його професійної діяльності. Проведені власні дослідження в регіонах країни свідчать, що тільки 3-5% фармацевтичних працівників знайомі з поняттям "синдром емоційного вигорання". Так у м. Києві до 10% осіб  ознайомлені з цим поняттям, в той же час 54% працівників у віці 45-60 років і 32% у віці 25-30 років щодня потрапляють в стресові ситуації і мають різні захворювання, що свідчать про наявність синдрому "професійного вигорання"

Стандартные образцы температуры плавления органических веществ: перспективы разработки

The field of the melting point measurements of high-purity organic substances today includes a large number of measuring instruments used in the field of medicine, biology, and the production of perfumery and cosmetic products.The purpose of the research is to identify the features and justify approaches to the development of melting point certified reference materials of organic substances provided with metrological traceability to the SI base measurement units «temperature» (°C).The objectives of the research included justification of the choice of substances-candidates for CRMs; determination of the certification procedure for RMs; establishment of restrictions affecting the certification procedure; estimation of uncertainty for certified values of the melting point CRMs.In the course of the research, a state analysis of metrological assurance in the field of melting point measurements was performed. An overview of the reference complex designed to measure the melting point and purity of organic substances in the range from +40 °C to +250 °C is presented, its functional diagram is given. The basic requirements for substancescandidates for CRMs are identified. The study presents the results of determining the melting point of benzophenone, benzoic acid, succinic acid, anthracene, and caffeine obtained by direct measurements of the phase transition temperature and by indirect measurements based on recording the moment of optical transparency of the substances under study. The results of interlaboratory comparisons on samples of the studied substances are presented, which made it possible to obtain reliable data on the temperature of the emergence of optical transparency at different heating rates. A method for reconciling the results is proposed; it consists in presenting the certified value of the melting point determined by the method of direct measurements of the phase transition temperature in the thermodynamic mode, as well as the certified values of the optical transparency temperature at various heating rates as additional characteristics of the substance in the passports of the developed CRMs. Research objectives for further work are formulated.The theoretical significance of the results obtained lies in the development of theoretical and methodological approaches to the certification of melting point CRMs based on pure organic substances, which make it possible to improve the measurement accuracy in the field of thermal analysis at a higher quality level.Область измерений температуры плавления высокочистых органических веществ на сегодняшний день включает большое количество средств измерений, используемых в сфере медицины, биологии, производства парфюмерно-косметической продукции.Цель данного исследования – выявление особенностей и обоснование подходов к разработке стандартных образцов температуры плавления органических веществ, обеспеченных метрологической прослеживаемостью к основным единицам SI величины «температура» (°C).В задачи исследования входило обоснование выбора веществ-кандидатов на роль СО; определение процедуры аттестации СО; установление ограничений, влияющих на процедуру аттестации; оценка неопределенности для аттестованных значений температуры плавления СО.В ходе исследования выполнен анализ состояния метрологического обеспечения в области измерений температуры плавления. Представлено краткое описание эталонного комплекса, предназначенного для измерений температуры плавления и степени чистоты органических веществ в диапазоне от +40 °C до +250 °C, приведена его функциональная схема. Сформулированы основные требования к веществам –  кандидатам на роль СО. Рассмотрены результаты определения температуры плавления бензофенона, бензойной кислоты, янтарной кислоты, антрацена и кофеина, полученные методом прямых измерений температуры фазового перехода и методом косвенных измерений, основанным на регистрации момента оптической прозрачности исследуемых веществ. Представлены результаты межлабораторных сличительных испытаний на образцах исследуемых веществ, позволившие получить достоверные данные по температуре возникновения оптической прозрачности при различной скорости нагрева. Предложен способ согласования результатов, заключающийся в представлении в паспортах разрабатываемыхСО аттестованного значения температуры плавления, определяемой методом прямых измерений температуры фазового перехода в термодинамическом режиме, а также аттестованных значений температуры оптической прозрачности при различных скоростях нагрева, как дополнительных характеристик вещества. Сформулированы исследовательские задачи для дальнейшей работы.Теоретическая значимость полученных результатов заключается в разработке теоретико-методологических подходов к процедуре аттестации СО температуры плавления на основе чистых органических веществ, позволяющих на более качественном уровне повысить точность проводимых измерений в области термического анализа

Bone marrow MRI after autologous transplantation and the effect of residual tumor on progression-free survival of multiple myeloma patients

Background . The study of influence of residual tumor mass, determined by magnetic resonance imaging (MRI), on the progression-free survival (PFS) remains an actual problem. Since the visual assessment of tumor bone marrow lesion can be one of the criteria for the subsequent personalized treatment choice in multiple myeloma patients.The objective of study was to determine the effect of bone marrow lesions detected by MRI after autologous hematopoietic stem cells transplantation (auto-HSCT) on PFS in multiple myeloma patients.Materials and methods . The prospective study included 60 patients who underwent spine and pelvic bones MRI on the 100 th day after autoHSCT.Results . Focal bone marrow changes were found in 47 of them – from 1 to 56 lesions (mean 6 ± 9). Significant (p = 0.01) differences of PFS in multiple myeloma patients depending on the presence or absence of tumor mass on 100 th day after auto-HSCT were revealed: with MRI negative status, 2-year PFS was 89 % versus 50 % in a group of patients with residual tumor mass.Conclusion . MRI-negative status after auto-HSCT is a favorable prognostic factor contributing to prolonged disease-free survival

On the roots of the Poincare structure of asymptotically flat spacetimes

The analysis of vacuum general relativity by R. Beig and N. O Murchadha (Ann. Phys. vol 174, 463 (1987)) is extended in numerous ways. The weakest possible power-type fall-off conditions for the energy-momentum tensor, the metric, the extrinsic curvature, the lapse and the shift are determined, which, together with the parity conditions, are preserved by the energy-momentum conservation and the evolution equations. The algebra of the asymptotic Killing vectors, defined with respect to a foliation of the spacetime, is shown to be the Lorentz Lie algebra for slow fall-off of the metric, but it is the Poincare algebra for 1/r or faster fall-off. It is shown that the applicability of the symplectic formalism already requires the 1/r (or faster) fall-off of the metric. The connection between the Poisson algebra of the Beig-O Murchadha Hamiltonians and the asymptotic Killing vectors is clarified. The value H[K^a] of their Hamiltonian is shown to be conserved in time if K^a is an asymptotic Killing vector defined with respect to the constant time slices. The angular momentum and centre-of-mass, defined by the value of H[K^a] for asymptotic rotation-boost Killing vectors K^a, are shown to be finite only for 1/r or faster fall-off of the metric. Our center-of-mass expression is the difference of that of Beig and O Murchadha and the spatial momentum times the coordinate time. The spatial angular momentum and this centre-of-mass form a Lorentz tensor, which transforms in the correct way under Poincare transformations.Comment: 34 pages, plain TEX, misleading notations changed, discussion improved and corrected, appearing in Class. Quantum Gra

Prevalence of professional burnout among practicing cardiologists in the constituent entities of the Russian Federation

The burnout syndrome among healthcare professionals is a headline problem in the world, as it leads to poor health of medical workers, affects patient satisfaction with health care and the healthcare system as a whole. At the same time, existing preventive measures can improve the well-being of staff.Aim. To study the prevalence of professional burnout syndrome among practicing cardiologists in the Russian Federation (RF).Material and methods. This cross-sectional study was carried out using the method of online anonymous surveying. The inclusion criterion was the current practical activity in the RF. The study involved 452 cardiologists from 8 federal districts (women; n=377, 83,4%), 48,2% of which worked in a hospital. Occupational burnout was assessed using the Maslach Burnout Inventory (MBI) questionnaire in the Russian language adaptation for healthcare workers by N. E. Vodopyanova and E. S. Starchenkova. The score was calculated on three subscales (emotional exhaustion, depersonalization, personal accomplishment), the maximum score for the subscales was 54, 30 and 48, respectively. The personal accomplishment subscale is the opposite as follows: the higher the score, the less the symptom severity. Additionally, demographic parameters, working conditions, the desire to change job and field of activity were taken into account. Regression analysis was used to establish associations of burnout with factors.Results. The median score of the emotional exhaustion subscale was 29,5 (23,0; 35,0) points, depersonalization — 12,0 (8,0; 16,0) and personal accomplishment — 32,0 (28,0; 37,0). Men had higher depersonalization score than women as follows: 15,0 (10,0; 18,0) vs 11,0 (8,0; 15,0), p=0,001. High degrees of emotional exhaustion and depersonalization (burnout) were found in 235 (52%) cardiologists, while all three symptoms simultaneously — in 132 (29,2%) doctors. There were no symptoms of burnout in 84 (18,6%) cardiologists. A high degree of burnout was associated with a desire to change job (p<0,001).Conclusion. A high prevalence of professional burnout among practicing cardiologists in the RF was revealed, which, in turn, is associated with the desire to change job or occupation

The rare decay η→ππγγ\eta\to\pi\pi\gamma\gamma in chiral perturbation theory

We investigate the rare radiative eta decay modes $\eta\to\pi^+\pi^-\gamma\gamma$ and $\eta\to\pi^0\pi^0\gamma\gamma$ within the framework of chiral perturbation theory at $O(p^4)$. We present photon spectra and partial decay rates for both processes as well as a Dalitz contour plot for the charged decay.Comment: 26 pages, RevTex, 10 figures, to appear in Phys. Rev.