46 research outputs found
Second virial coefficients of light nuclear clusters and their chemical freeze-out in nuclear collisions
Here we develop a new strategy to analyze the chemical freeze-out of light
(anti)nuclei produced in high energy collisions of heavy atomic nuclei within
an advanced version of the hadron resonance gas model. It is based on two
different, but complementary approaches to model the hard-core repulsion
between the light nuclei and hadrons. The first approach is based on an
approximate treatment of the equivalent hard-core radius of a roomy nuclear
cluster and pions, while the second approach is rigorously derived here using a
self-consistent treatment of classical excluded volumes of light (anti)nuclei
and hadrons. By construction, in a hadronic medium dominated by pions, both
approaches should give the same results. Employing this strategy to the
analysis of hadronic and light (anti)nuclei multiplicities measured by ALICE at
TeV and by STAR at GeV, we got rid
of the existing ambiguity in the description of light (anti)nuclei data and
determined the chemical freeze-out parameters of nuclei with high accuracy and
confidence. At ALICE energy the nuclei are frozen prior to the hadrons at the
temperature MeV, while at STAR energy there is a
single freeze-out of hadrons and nuclei at the temperature
MeV. We argue that the found chemical freeze-out volumes of nuclei can be
considered as the volumes of quark-gluon bags that produce the nuclei at the
moment of hadronization.Comment: 15 pages, 4 figures, 3 table
The development of attenuation compensation models of fluorescence spectroscopy signals
This study examines the effect of blood absorption on the endogenous fluorescence signal intensity of biological tissues. Experimental studies were conducted to identify these effects. To register the fluorescence intensity, the fluorescence spectroscopy method was employed. The intensity of the blood flow was measured by laser Doppler flowmetry. We proposed one possible implementation of the Monte Carlo method for the theoretical analysis of the effect of blood on the fluorescence signals. The simulation is constructed as a four-layer skin optical model based on the known optical parameters of the skin with different levels of blood supply. With the help of the simulation, we demonstrate how the level of blood supply can affect the appearance of the fluorescence spectra. In addition, to describe the properties of biological tissue, which may affect the fluorescence spectra, we turned to the method of diffuse reflectance spectroscopy (DRS). Using the spectral data provided by the DRS, the tissue attenuation effect can be extracted and used to correct the fluorescence spectra
Разработка учебного курса «иностранный язык» в электронно-образовательной среде УрГЮУ
Статья посвящена актуальной на сегодняшний день проблеме использования возможностей электронной образовательной платформы Moodle в обучении иностранным языкам в юридическом вузе. Наличие электронной образовательной среды является главным условием для успешного использования технологии e-learning. Своевременность данной работы несомненна, так как в связи с переходом на дистанционное обучение возросла потребность разработки электронных учебных курсов, обеспечивающих планирование самостоятельной деятельности обучающихся, синхронное и асинхронное общение с преподавателем, достаточный спектр контрольных мероприятий. В статье исследуются основные принципы построения учебного курса и структура системы. Авторы раскрывают возможности работы с системой на примере собственного опыта работы.L’article est consacré aux questions actuelles de l’utilisation des opportunités de la plateforme web d’apprentissage en ligne Moodle dans l’enseignement des langues étrangères à la faculté de droit. La mise en place d’un espace numérique de travail est la condition majeure d’une large utilisation des technologies de l’e-enseignement. La pertinence de ce sujet est évidente car dans le cadre de la transition vers la formation à distance, les établissements d’enseignement supérieur sont engagés dans le déploiement des parcours numériques qui favorisent le travail individuel et en équipes des étudiants, leur communication synchrone et asynchrone avec l’enseignant et offrent un éventail approprié de mesures de contrôle. L’article determine les principes de base de la conception d’une ressource numérique éducative et décrit sa structure. Les auteurs tiennent à faire part de leur expérience et à révéler les potentialités pédagogiques des plateformes numériques
Application of optical non-invasive methods to diagnose the state of the lower limb tissues in patients with diabetes mellitus
The paper shows the possibility of assessing the functional state of microcirculatory-tissue systems of patients with diabetes mellitus by laser Doppler flowmetry (LDF), diffuse reflectance spectroscopy (DRS) and fluorescence spectroscopy (FS) methods. A review of the existing non-invasive optical technologies used to assess the state of microcirculation and oxygen metabolism in tissues of patients with diabetes is conducted. A series of experimental studies involving 76 patients with diabetes and 46 healthy volunteers was carried out. A wavelet analysis of LDF-grams was used to evaluate the adaptive changes of microcirculation during the temperature tests. The obtained data revealed that the proposed methodology in the form of combined use of several diagnostic technologies (LDF, FS and DRS) allows us to detect the presence or absence of trophic disorders and to evaluate adaptation processes during thermal tests
The blood perfusion and NADH/FAD content combined analysis in patients with diabetes foot
Skin blood microcirculation and the metabolism activity of tissue were examined on the patients with type 2 diabetes. Laser Doppler flowmetry (LDF) with 1064 nm laser light source and fluorescence spectroscopy (FS) with excitation light of 365 nm and 450 nm have been used to monitor the blood perfusion and the content of coenzymes NADH and FAD. Concluding, the proposed combined LDF and tissue FS approach allows to identify the significant violations in the blood microcirculation and metabolic activity for type 2 diabetes patients
Induced surface and curvature tension equation of state for hadron resonance gas in finite volumes and its relation to morphological thermodynamics
Here we develop an original approach to investigate the grand canonical
partition function of the multicomponent mixtures of Boltzmann particles with
hard-core interaction in finite and even small systems of the volumes above 20
fm. The derived expressions of the induced surface tension equation of
state are analyzed in details. It is shown that the metastable states, which
can emerge in the finite systems with realistic interaction, appear at very
high pressures at which the hadron resonance gas, most probably, is not
applicable at all. It is shown how and under what conditions the obtained
results for finite systems can be generalized to include into a formalism the
equation for curvature tension. The applicability range of the obtained
equations of induced surface and curvature tensions for finite systems is
discussed and their close relations to the equations of the morphological
thermodynamics are established. The hadron resonance gas model on the basis of
the obtained advanced equation of state is worked out. Also, this model is
applied to analyze the chemical freeze-out of hadrons and light nuclei with the
number of (anti-)baryons not exceeding 4, including the most problematic ratios
of hyper-triton and its antiparticle. Their multiplicities were measured by the
ALICE Collaboration in the central lead-lead collisions at the center-of-mass
energy 2.76 TeV.Comment: 24 pages, 3 figures and 1 tabl
Clinical and epidemiological characteristics and effectiveness of antiviral therapy for COVID-19 in children: The experience of the first year of the pandemic
Background. The use of antiviral agents can shorten the duration of the viral infection. The aim: to study the clinical and epidemiological features and the effectiveness of antiviral therapy for new coronavirus infection (COVID-19) in outpatient children.Materials and methods. From April 2020 to March 2021, 9334 outpatient children aged from 0 months to 17 years were randomly tested for new coronavirus infection. SARS-CoV-2 RNA was detected in oropharyngeal and nasal material by PCR. Patients with confirmed new coronavirus infection were prescribed interferon-alpha (IFN-α) intranasally, antiviral agents of systemic action. The control group consisted of children with COVID-19 who did not receive treatment.Results. When examining clinically healthy contact children, SARS-CoV-2 RNA was detected in 7.4 % of cases. In the structure of ARI, the specific weight of COVID-19 was 12.3 % with the peak incidence in April-May (up to 22.8 %) and NovemberDecember (up to 30.0 %). In half of the cases, children became infected in the family, and usually adults were the index patient. In 47.7 % of cases, an asymptomatic form of COVID-19 was registered without significant differences in patients of different ages. In one third of children with concomitant pathology, the disease was asymptomatic, in half it was mild, in other cases moderate severity was diagnosed. The clinical picture of COVID-19 did not differ from other ARIs. Anosmia (9.4 %) in half of the cases was combined with ageusia (4.4 %) and was significantly more common in boys. The duration of clinical manifestations in children of the control group and those who received antiviral therapy did not statistically significantly differ in mild and severity of the disease. Also, various antiviral therapy options did not significantly affect the duration of SARS-CoV-2 detection in children with various forms of COVID-19.Conclusion. In the first year of the pandemic, the novel coronavirus infection did not dominate the pattern of respiratory diseases in outpatient children. Further research is required to develop pediatric guidelines for the treatment of COVID-19 at the outpatient stage
Multimodal optical measurement for study of lower limb tissue viability in patients with diabetes mellitus
According to the International Diabetes Federation, the challenge of early stage diagnosis and treatment effectiveness monitoring in diabetes is currently one of the highest priorities in modern healthcare. The potential of combined measurements of skin fluorescence and blood perfusion by the laser Doppler flowmetry method in diagnostics of low limb diabetes complications was evaluated. Using Monte Carlo probabilistic modeling, the diagnostic volume and depth of the diagnosis were evaluated. The experimental study involved 76 patients with type 2 diabetes mellitus. These patients were divided into two groups depending on the degree of complications. The control group consisted of 48 healthy volunteers. The local thermal stimulation was selected as a stimulus on the blood microcirculation system. The experimental studies have shown that diabetic patients have elevated values of normalized fluorescence amplitudes, as well as a lower perfusion response to local heating. In the group of people with diabetes with trophic ulcers, these parameters also significantly differ from the control and diabetes only groups. Thus, the intensity of skin fluorescence and level of tissue blood perfusion can act as markers for various degrees of complications from the beginning of diabetes to the formation of trophic ulcers
Серопревалентность сотрудников первичного звена здравоохранения Санкт-Петербурга в период эпидемического неблагополучия по кори
The measles situation is still unstable — there are imported cases, the formation of nosocomial foci with the involvement of medical personnel, patients and visitors of medical institutions.Objective of the study: to assess the level of seroprevalence of primary health care workers in St. Petersburg during the period of epidemic trouble with measles.Materials and methods: An open retrospective randomized uncontrolled study of the intensity of specific immunity to measles in 980 employees aged 18 to 78 years, examined in July-September 2018, was carried out. The level of anti-measles IgG antibodies was determined by the method of enzyme-linked immunosorbent assay (810 people) and passive hemagglutination reactions (170 people). The results are presented with the indication of the shares (%) and the calculation of the 95% confidence interval according to Clopper — Pearson. Differences between groups were assessed using Pearson's chi-square test (%2). Differences in the groups were considered statistically significant when the criterion level was p < 0.05.Results: It was found that 8.2% of personnel are not protected against measles infection. At the same time, the number of seronegative persons among doctors (8.1 %), nurses (7.7%) and non-medical workers (9.6%) differed statistically. Age-related differences in the immune layer were revealed — the greatest susceptibility was observed in persons under 30 years of age (1 8.3%). Anti-measles antibodies in those who had been ill persisted for a long time and at a high level. At the same time, the intensity of post-vaccination immunity decreased over time, and 20 years after immunization, the number of seronegative individuals increased significantly. Only 64.1 % of those surveyed had two vaccinations, more than a third were immunized once. Nevertheless, the proportion of people unprotected from measles exceeded the criterion of epidemic well-being with the same frequency in both groups (9.2% and 1 0.4%, respectively).The results of a serological study showed that the presence of a record of two vaccinations in the certificate in 9.2% of cases does not guarantee protection in case of contact with a patient with measles. Only a serological examination is evidence of specific immunity to measles infection.Ситуация по кори до настоящего времени остается нестабильной — отмечаются завозные случаи, формирование внутрибольничных очагов с вовлечением медицинского персонала, пациентов и посетителей лечебных учреждений.Цель исследования: оценить уровень серопревалентности сотрудников первичного звена здравоохранения Санкт-Петербурга в период эпидемического неблагополучия по кори.Материалы и методы: Проведено открытое ретроспективное рандомизированное неконтролируемое исследование напряженности специфического иммунитета к кори у 980 сотрудников в возрасте от 18 до 78 лет, обследованных в июле-сентябре 2018 г. Уровень противокоревых антител класса IgG определялся методом иммуноферментного анализа (810 чел.) и реакции пассивной гемагглютинации (170 чел.). Результаты представлены с указанием долей (%) и расчетом 95% доверительного интервала по Клопперу-Пирсону. Различия между группами оценивали с помощью критерия %2 Пирсона. Различия в группах считались статистически значимыми при уровне критерия p < 0,05.Результаты: Установлено, что 8,2% персонала не защищены против коревой инфекции. При этом количество серонегативных лиц среди врачей (8,1%), среднего медицинского персонала (7,7%) и немедицинских работников (9,6%) статистически не различалось. Выявлены возрастные различия в иммунной прослойке — наибольшая восприимчивость отмечена у лиц моложе 30 лет (18,3%). Противокоревые антитела у переболевших сохранялись длительно и на высоком уровне. В то же время напряженность поствакцинального иммунитета с течением времени снижалась и через 20 лет после иммунизации значительно возросло количество серонегативных лиц. Две прививки имели только 64,1 % обследованных, более трети оказались иммунизированы однократно. Тем не менее доля незащищенных от кори лиц превышала критерий эпидемического благополучия с одинаковой частотой в обеих группах (9,2% и 1 0,4% соответственно).Результаты серологического исследования показали, что наличие в сертификате записи о двух прививках в 9,2% случаях не гарантирует защиту при контакте с больным корью. Только серологическое обследование является доказательством наличия специфического иммунитета к коревой инфекции
Production of {\pi}+ and K+ mesons in argon-nucleus interactions at 3.2 AGeV
First physics results of the BM@N experiment at the Nuclotron/NICA complex
are presented on {\pi}+ and K+ meson production in interactions of an argon
beam with fixed targets of C, Al, Cu, Sn and Pb at 3.2 AGeV. Transverse
momentum distributions, rapidity spectra and multiplicities of {\pi}+ and K+
mesons are measured. The results are compared with predictions of theoretical
models and with other measurements at lower energies.Comment: 29 pages, 20 figure