Luminescence and vacuum ultraviolet excitation spectroscopy of cerium doped Gd3Ga3Al2O12 single crystalline scintillators under synchrotron radiation excitations

Authors gratefully acknowledge the financial support from the Latvian Science Council grant LZP-2018/2-0358 . The research leading to this result has been supported by the project CALIPSO plus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON2020 . The work of A.P.K. was supported by the Ministry of Science and Higher Education of the Russian Federation , state contracts No. 11.6181.2017/ITR .Cerium doped Gd3Ga3Al2O12 (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg2+, Ca2+), trivalent (Sc3+) or tetravalent (Zr4+, Ti4+) ions have been studied by means of the excitation luminescence spectroscopy in vacuum ultraviolet spectral range. Synchrotron radiation from the undulator beam was utilized for the luminescence excitation in the energy range from 4.5 to 800 eV. The influence of the co-dopant ions on the excitonic transitions as well as on the intrinsic defects in GGAG was revealed examining the luminescence emission and excitation spectra of both Gd3+ and Ce3+ ions in all single crystals studied. Special attention was paid to the analysis of Ce3+ excitation spectra in VUV spectral range (4.5–45 eV) where multiplication of electronic excitation (MEE) processes occur. It was obtained that GGAG:Ce single crystals having different co-dopant ions reveal distinguished efficiency of MEE. The role of intrinsic defects in MEE processes in the co-doped GGAG:Ce single crystals was elucidated.Latvian Science Council LZP-2018/2-0358,730872; Ministry of Science and Higher Education of the Russian Federation 11.6181.2017/ITR; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²https://www.sciencedirect.com/science/article/pii/S2211379719334527?via%3Dihu

Metabolic and cardiovascular features of the course of type 2 diabetes mellitus in men with hypogonadism

Introduction. Androgenic deficiency is an important pathogenetic element in the development of metabolic syndrome and cardiovascular diseases in men. It has been proven that in male patients with type 2 diabetes, hypogonadism develops much more often. Objective – to study the metabolic and cardiovascular features of the course of type 2 diabetes mellitus (T2DM) in men with androgen deficiency.Materials and methods. The study included 124 men with type 2 diabetes. To diagnose hypogonadism, the levels of total testosterone (T), sex hormone binding globulin (SHBG), albumin and luteinizing hormone (LH) were measured. Free testosterone (free T) levels were calculated using a calculator from Ghent University Hospital, Belgium. A retrospective analysis of case histories was carried out (spectrum of late complications, the presence of heart attacks and strokes, laboratory data – total cholesterol (CS), triglycerides (TG), fasting blood plasma glucose, basal insulin level, glycated hemoglobin (HbA1c)). The HOMA-IR index was used to determine the degree of insulin resistance.Results. The average age of men was 57.39 ± 9.41 years. The incidence of laboratory-confirmed hypogonadism is 50.81%. An average positive correlation was found between androgen deficiency and the incidence of non-fatal cardiovascular events (r = 0.45, p < 0.05). There was no statistically significant relationship between the presence of hypogonadism and the incidence and degree of late complications of T2DM. Patients with low T levels tended to have higher HOMA-IR values compared to patients with normal T levels (p < 0.05). At the same time, the indicators of carbohydrate and lipid metabolism did not differ significantly in these groups (p > 0.05).Conclusions. The revealed incidence of hypogonadism in men with T2DM corresponds to the data of international studies. The presence of a significant correlation between low testosterone levels and cardiovascular events in patients with T2DM suggests that hypogonadism can be used as an additional criterion for cardiovascular risk. Testosterone deficiency exacerbates insulin resistance, which can lead to weight gain and impair carbohydrate metabolism

Liver pathomorphology of Mus musculus C57BL6 on atherogenic diet

Atherosclerosis is one of the leading causes of disability and death worldwide. Liver plays a huge role in pathogenesis of atherogenic dislipidemia, development and progression of atherosclerotic lesions. We studied the effect of atherogenic diet on liver morphology in animal model of diet-induced atherosclerosis in mice Mus musculus C57BI6. This strain has a natural ability to develop atherosclerosis, while some other mouse stains has not. After 14 weeks on atherogenic diet a severe hepathomegaly (9% of body mass) and lobular structure deformation was found. We also observed signs of micro- and macrovesicular steatosis, cell apoptosis, fibrosis and inflammatory leukocyte infiltration. So, liver not only plays an important role in dislipidemia, but it is also a target-organ in lipid metabolism imbalance

Approaches to Assessing the Safety of Medicines during the COVID-19 Pandemic Using the Example of Azithromycin

Most of the medicines used to treat the novel coronavirus infection (COVID-19) are either approved under an accelerated procedure or not approved for the indication. Consequently, their safety requires special attention.The aim of the study was to review methodological approaches to collecting data on the safety of medicines, using COVID-19 treatment regimens involving azithromycin as a case study.Materials and methods: PubMed® (MEDLINE), Scopus, eLIBRARY, and Cyberleninka databases were searched for publications on azithromycin as part of combination therapy for COVID-19 in 2020–2021. Search queries included names of the medicinal product or its pharmacotherapeutic group and words describing adverse drug reactions (ADRs) during treatment.Results: the analysis included 7 publications presenting the results of studies covering the use of azithromycin as part of COVID-19 combination therapy in more than 4000 patients. Most commonly, the patients receiving COVID-19 therapy including azithromycin developed cardiovascular ADRs (up to 30% of azithromycin prescription cases). In 3 of the analysed publications, safety information was collected through spontaneous reporting and active identification based on the findings of laboratory and instrumental investigations performed during the clinical studies; in other 3, only spontaneous reports were used; and in the last one, ADR database information was studied.Conclusion: currently, information on ADRs associated with the use of medicines is mainly gathered via spontaneous reporting. Direct sourcing of information on personal experiences with a certain product from patients, among other means through social media analysis, opens a promising direction towards the improvement of existing approaches to collecting safety data

Superconductivity in ultra-thin carbon nanotubes and carbyne-nanotube composites: An ab-initio approach

The superconductivity of the 4-Å single-walled carbon nanotubes (SWCNTs) was discovered more than a decade ago, and marked the breakthrough of finding superconductivity in pure elemental undoped carbon compounds. The van Hove singularities in the electronic density of states at the Fermi level in combination with a large Debye temperature of the SWCNTs are expected to cause an impressively large superconducting gap. We have developed an innovative computational algorithm specially tailored for the investigation of superconductivity in ultrathin SWCNTs. We predict the superconducting transition temperature of various thin carbon nanotubes resulting from electron-phonon coupling by an ab-initio method, taking into account the effect of radial pressure, symmetry, chirality (N,M) and bond lengths. By optimizing the geometry of the carbon nanotubes, a maximum Tc of 60 K is found. We also use our method to calculate the Tc of a linear carbon chain embedded in the center of (5,0) SWCNTs. The strong curvature in the (5,0) carbon nanotubes in the presence of the inner carbon chain provides an alternative path to increase the Tc of this carbon composite by a factor of 2.2 with respect to the empty (5,0) SWCNTs. © 2017 Elsevier Lt

INFLUENCE OF ERBIUM QUANTITY ON LUMINESCENCE PROPERTIES OF ER-DOPED GADOLINIUM OXIDE

The study focuses on the characterization of the gadolinium oxide and Er - doped gadolinium oxide powders prepared by coprecipitation of hydroxides. The specific surface of gadolinium oxide, the average size and oxides phase were determined. It was found that Er – doping improves luminescence

Реальная практика проведения клинико-экономических исследований лекарственных средств, входящих в федеральную программу высокозатратных нозологий

Objective: to assess the compliance of the actual practice of conducting clinical and economic research with the requirements applicable in the Russian Federation (RF) when including drugs in the Federal Program of High-Cost Nosologies (HCN).Material and methods. In the CyberLeninka and eLibrary databases, a search was made for clinical and economic studies of medicines included in the HCN list published in the RF in the period from 2011 to June 2021.Results. Information was obtained on 23 published clinical and economic studies of the effectiveness of drugs, which is less than 30% of all drugs included in the HCN program during the specified period. More than half of the studies of chronic disabling diseases had a modeling horizon of 1 year. The sensitivity analysis of the results in over 1/3 of cases considered only the deviation of the price of the strategies under consideration, and in a quarter of cases it was not carried out at all. Only 4 studies evaluated the increase in quality-adjusted life year, although, for chronic disabling diseases, quality of life is one of the key performance indicators.Conclusion. In the RF, less than 30% of the results of pharmacoeconomical studies of drugs included in the HCN Program are published, which does not allow to make adequate evaluation of pharmacoeconomical approaches to its formation. To analyze the effectiveness of the tools used in assessing the economic efficiency of expensive medical technologies, a further retrospective research of the studies conducted in the RF is required.Цель: оценка соответствия реальной практики проведения клинико-экономических исследований действующим в Российской Федерации (РФ) требованиям, предъявляемым при включении лекарственных средств (ЛС) в федеральную программу высокозатратных нозологий (ВЗН).Материал и методы. В базах данных КиберЛенинка и eLibrary проведен поиск клинико-экономических исследований ЛС, включенных в перечень ВЗН, которые были опубликованы в РФ в период с 2011 г. по июнь 2021 г.Результаты. Получены сведения о 23 клинико-экономических исследованиях эффективности ЛС, что составляет менее 30% от всех ЛС, включенных в указанный период в программу ВЗН. Более половины исследований хронических инвалидизирующих заболеваний имели горизонт моделирования 1 год. Анализ чувствительности результатов более чем в 1/3 случаев учитывал только отклонение цены рассматриваемых стратегий, а в 1/4 случаев такой анализ вообще не проводился. Только в 4 исследованиях оценивали прирост лет качественной жизни, несмотря на то что для хронических инвалидизирующих заболеваний качество жизни – один из ключевых показателей эффективности.Заключение. В РФ публикуется менее 30% результатов фармакоэкономических исследований ЛС, включенных в программу ВЗН, что не позволяет в полной мере оценить фармакоэкономические подходы к ее формированию. Для анализа эффективности инструментов, используемых при оценке экономической эффективности дорогостоящих медицинских технологий, требуется дальнейшее ретроспективное изучение проведенных в РФ исследований.

Многоугловые спектрофотометрические методы отражения для определения коэффициентов преломления

Features of development and application of methods for performing refractive index measurements based on multi-angle spectrophotometric reflection methods are considered. The influence of the shape, size, and surface treatment of samples on their spectral reflection dependences is described. It is shown that it is possible to determine the refractive coefficients using two spectrophotometric methods: the reflection spectrum from one face at a small angle of incidence of light close to normal, and the reflection method at the incidence of light at the Brewster angle. The method of reflection at an angle of incidence close to normal can be used in the case of a non–absorbing sample characterized by an extinction coefficient not exceeding (10-6—10-4). This method is an «express method», because it allows you to immediately obtain the dispersion dependence of the refractive index. The method allows us to measure the dispersion dependences of refractive coefficients for samples whose shape excludes multiple reflections — plates with one polished side; plates of large thickness, polished on two sides; prisms or plates with non-parallel faces. When measuring using the Brewster method, there are no requirements for the value of the extinction coefficient of the sample (absorption), you can use a sample of any shape, including polished plates on both sides. However, the resulting values of refractive indices are discrete, and a large array of measurement results must be accumulated. The measurement accuracy of both methods was determined, which is Δ = ±0,001 with a confidence probability P = 0,95. The applicability of spectrophotometric measurement methods is shown for samples of gadolinium-aluminum-gallium garnet, which is related to cubic crystals, characterized by the presence of a single refractive index. It is shown that the values of the refractive indices obtained by these two methods are well correlated within the accuracy of measurements.Рассмотрены особенности разработки и применения методик выполнения измерений коэффициентов преломления, основанных на многоугловых спектрофотометрических методах отражения. Описано влияние формы, размеров и обработки поверхности образцов на их спектральные зависимости отражения. Показана возможность определения коэффициентов преломления двумя спектрофотометрическими методами: по спектру отражения от одной грани при малом угле падения света, близком к нормальному, и методом отражения при падении света при угле Брюстера. Метод отражения при угле падения, близком к нормальному, может применяться в случае непоглощающего образца, который характеризуется коэффициентом экстинкции не превышающем (10-6—10-4). Этот метод является «экспресс-методом», поскольку позволяет сразу получать дисперсионную зависимость коэффициента преломления. Метод позволяет измерять дисперсионные зависимости коэффициентов преломления для образцов, форма которых исключает многократные отражения: пластин с одной шлифованной стороной; пластин большой толщины, полированных с двух сторон; призм или пластин с неплоскопараллельными гранями. При измерении по методу Брюстера не предъявляются требования к значению коэффициента экстинкции образца (поглощению), можно использовать образцы любой формы, в том числе, полированные с двух сторон пластины малой толщины. Однако получаемые значения коэффициентов преломления дискретны, требуется накопление большого массива результатов измерений. Определена точность измерений обоих методов, которая составляет Δ = ±0,001 при доверительной вероятности P = 0,95. Применимость спектрофотометрических методик измерения показана для образцов гадолиний-алюминий-галлиевого граната, относящегося к кристаллам кубической сингонии и характеризующегося наличием одного коэффициента преломления. Показано, что значения коэффициентов преломления, полученные данными методами, хорошо соотносятся в пределах точности измерений

A SORPTION OF URANIUM BY STRONG BASE ANION ION-EXCHANGE BEADS FROM SULFURIC-ACID LEACHING SOLUTIONS

Sorption of uranuim from sulfuric-acid leaching solutions by two gel type anion ion-exchange beads were explored. The Purolite A660 had a value of uranium capacity larger than AMP. Dynamic and static sorption parameters were identified for both elements