SLOW QUASIKINETIC CHANGES IN WATER-LACTOSE COMPLEXES DURING STORAGE

Objective: To investigate kinetic changes in the spectral characteristics by Fourier Transform Infrared spectroscopy (FTIR) of water-lactose complexes (SMC), derived during the manufacturing process of the drug, containing release-active forms of antibodies. Methods: lactose monohydrate substance, saturated with release-active forms of affinity-purified polyclonal rabbit antibodies to recombinant human interferon-gamma (RA forms of Abs); tablets produced from this substance by direct compression after the addition of excipients (microcrystalline cellulose, magnesium stearate). Powdered and tableted placebo samples saturated with technologically processed water or phosphate-buffered saline, as well as with intact ethanol were used as control. Kinetic changes in SMC were studied using an Agilent Cary 630 FTIR spectrophotometer with a diamond ATR accessory (Agilent Technologies, USA). We used the method of X-ray fluorescence spectroscopy (EDX-7000 Shimadzu energy dispersive X-ray fluorescence spectrometer) to track changes in the fluorescence signal at certain wavelengths. The range of measured elements–11Na-92U. Results: Control of some technological characteristics of the obtained active substance (moisture, flowability) and dosage form (mean mass, disintegration rate) was used as indirect indicators of quality, but they did not allow reliably distinguishing intact lactose from the saturated one. Long-period oscillations on FTIR spectra were characteristic for all types of samples; oscillations occur at approximately two-week intervals; S/N indices were more stable for samples of RA forms of Abs than for placebo samples. On some days, the substance saturated with RA forms of Abs significantly differed from the intact lactose powder. The kinetics of the X-ray fluorescence intensity at certain wavelengths indicates the possibility of a periodic cooperative trigger transition of the system. Reversible conformational transitions are observed for powders on the 30th and 130th days (Kα 3.313 keV). For tablets at Kα 3.313 keV and Kα 1.740 keV small changes were visualized on those days (100–110th day) when hysteresis phenomena were recorded in the IR spectra of these samples. Conclusion: As a result, the evidence for a long-period dramatic conformational mobility of the water-lactose complex was obtained. Based on the data on the semiannual kinetics of IR spectra, a universal criterion for the identity of lactose powder saturated with RA forms of Abs was obtained. Also, it was confirmed that the lactose conformation state was changed by saturation with RA forms of Abs

Bjurböle L/LL4 ordinary chondrite properties studied by Raman spectroscopy, X-ray diffraction, magnetization measurements and Mössbauer spectroscopy

Bjurbole L/LL4 ordinary chondrite was studied using scanning electron microscopy with energy dispersive spectroscopy, Raman spectroscopy, X-ray diffraction, magnetization measurements and Mossbauer spectroscopy. The phase composition and the relative iron fractions in the iron-bearing phases were determined. The unit cell parameters for olivine, orthopyroxene and clinopyroxene are similar to those observed in the other ordinary chondrites. The higher contents of forsterite and enstatite were detected by Raman spectroscopy. Magnetization measurements showed that the temperature of the ferrimagnetic-paramagnetic phase transition in chromite is around 57 K and the saturation magnetic moment is similar to 7 emu/g. The values of the Fe-57 hyperfine parameters for all components in the Bjurbole Mossbauer spectrum were determined and related to the corresponding iron-bearing phases. The relative iron fractions in Bjurbole and the Fe-57 hyperfine parameters of olivine, orthopyroxene and troilite were compared with the data obtained for the selected L and LL ordinary chondrites. The Fe2+ occupancies of the M1 and M2 sites in silicate crystals were determined using both X-ray diffraction and Mossbauer spectroscopy. Then, the temperatures of equilibrium cation distribution were determined, using two independent techniques, for olivine as 666 K and 850 K, respectively, and for orthopyroxene as 958 K and 1136 K, respectively. Implications of X-ray diffraction, magnetization measurements and Mossbauer spectroscopy data for the classification of the studied Bjurbole material indicate its composition being close to the LL group of ordinary chondrites. (C) 2020 Elsevier B.V. All rights reserved.Peer reviewe

Finsler geometry modeling of reverse piezoelectric effect in PVDF

We apply the Finsler geometry (FG) modeling technique to study the electric field-induced strain in ferroelectric polymers. Polyvinylidene difluoride (PVDF) has a negative longitudinal piezoelectric coefficient, which is unusual in ferroelectrics, and therefore the shape changes in this material are hard to predict. We find that the results of Monte Carlo simulations for the FG model are in good agreement with experimental strain-electric field curves of PVDF-based polymers in both longitudinal and transverse directions. This implies that FG modeling is suitable for reproducing the reverse piezoelectric effect in PVDF

Hysteretic characteristics of a double stripline in the critical state

Analytical investigations of the critical state are carried out for a superconducting stripline consisting of two individual coplanar strips with an arbitrary distance between them. Two different cases are considered: a stripline with transport current and strips exposed to a perpendicular magnetic field. In the second case, the obtained solutions correspond to "fieldlike" (for unclosed strips) and "currentlike" (for a long rectangular superconducting loop) states in an isolated strip to which both a transport current and a magnetic field are applied with constant ratio.Comment: 8 pages, 6 figures. accepted by SS

Cell-mediated and humoral immunity during COVID-19 in the Republic of Crimea

The COVID-19 (coronavirus disease 2019) pandemic has spurred the development of highly effective quantitative methods for assessing the adaptive immune response to the SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus 2) virus. In order to assess the humoral component of the immune response, various methods for detecting immunoglobulins A, M, G are widely used. ELISPOT seems to be the most accessible and effective method to assess the level of T cells that specifically respond to the SARS-CoV-2 virus antigens.The aim. To assess cell-mediated and humoral immunity in COVID-19 in residents of the Republic of Crimea.Methods. The study was performed on 24 volunteers: the presence of coronavirus antibodies was determined by ELISA method, and the presence of contact with coronavirus proteins – by the ELISPOT “TigraTest®  SARS-CoV-2” method (Generium, Russia). For retrospective study of  humoral immunity in the population, we assessed 10 000 ELISA tests (ECOlab IgM and IgG, Russia) performed in our laboratory for the period from July 2020 to January 2022.Results. The results show the effectiveness of using the ELISPOT method to detect latent forms of coronavirus infection. It is important to note that there is statistically significant relationship between the timing of the disease and the number of spots in  both antigen panels. After vaccination against SARS-CoV-2, cell-mediated immunity lasts up to 6 months or more.Conclusions. As a result of the study, it was found that during 2021, the level of  immunization of the population of the Republic of Crimea against COVID-19 has significantly increased; the proportion of residents who have positive IgG test has increased from 27 % to 87 %. The results of ELISPOT studies using a set of reagents for in vitro detection of blood T-lymphocytes that specifically respond to SARS-COV-2 virus antigens (“TigraTest® SARS-CoV-2”) showed that this method is more sensitive than ELISA in detecting latent diseases

Balloon Dilatation of Esophageal Strictures in Children With Bullous Epidermolysis: Description of Case Series

Esophageal strictures are the most common complications of bullous epidermolysis in children. Strictures cause the development of dysphagia that prevents oral alimentation and receipt of an adequate amount of nutrients that is accompanied by a violation of nutritional status, weight loss, and delayed physical development of a child. Disturbed swallowing can also cause aspiration syndrome, pneumonia, and airway obstruction. To eliminate dysphagia and reduce the risk of complications, it is necessary to restore esophageal patency. The article describes the results of X-ray with assisted balloon dilatation in 19 children with bullous epidermolysis and dysphagia. It is shown that this method of esophagus recanalization allows to effectively and safely restore oral alimentation of children already in the first day after intervention with a gradual expansion of the diet

Опыт применения препарата бедаквилин у ребенка раннего возраста с лекарственно-устойчивым туберкулезом на фоне первичного иммунодефицита

The article describes a clinical case of the treatment of a young child with a complicated course of tuberculosis with multiple localizations and concurrent primary immunodeficiency. The new anti-tuberculosis drug of bedaquiline was successfully used in the treatment regimen. The child received bedaquiline for 6 months without any adverse events, after 2 months no acid-fast mycobacteria were detected, there were pronounced positive radiological changes which remained until the end of treatment. This clinical case provides evidence that bedaquiline can be used safely and effectively in MDR TB chemotherapy regimens in children under 5 years of age.Представлено клиническое наблюдение лечения ребенка раннего возраста с осложненным течением туберкулеза множественных локализаций на фоне первичного иммунодефицита. В схеме лечения успешно использован новый противотуберкулезный препарат бедаквилин. Ребенок получал бедаквилин в течение 6 мес. без нежелательных явлений, через 2 мес. прекратилось выделение кислотоустойчивых микобактерий, отмечалась выраженная положительная рентгенологическая динамика, сохранявшаяся до конца лечения. Клиническое наблюдение свидетельствует, что бедаквилин может быть безопасно и эффективно использован в схеме химиотерапии МЛУ-туберкулеза у детей младше 5 лет

Study of the processes of repolarization in ferroelectric polymer materials using computer simulation methods

Для дискретной модели, описывающей сегнетоэлектрический полимер, проведено компьютерное моделирование процессов переполяризации в зависимости от параметров внешнего электрического поля и энергетических констант модели. Показано, что при определенной частоте внешнего излучения существует максимум поглощательной способности системы.For a discrete model which describes a ferroelectric polymer, we perform computer simulation of the repolarization processes in dependence on the parameters of the external electric field and the energy constants of the model. We have shown that at the certain frequency the maximum of the absorbing capacity of the system exist.Работа выполнена в рамках гранта РНФ «Методы микроструктурного нелинейного анализа, волновой динамики и механики композитов в исследовании и дизайне современных метаматериалов и элементов конструкций на их основе» (№ 15-19-10008)

Characterization of toxigenic Corynebacterium diphtheriae strains isolated in Russia

The aim of the study was to characterize toxigenic strains of Corynebacterium diphtheriae by examining 12 toxigenic strains of C. diphtheriae isolated in Russia between January, 2017 to June, 2019. The morphological, toxigenic and biochemical properties of C. diphtheriae was studied. Genotyping of C. diphtheriae strains was performed using MLST and dtxR gene sequencing with subsequent phylogenetic analysis. Results. Toxigenic strains of C. diphtheriae were isolated in the Novosibirsk, Samara and Chelyabinsk Regions, the Khanty-Mansi Autonomous Okrug — Yugra as well as the Republic of Northern Ossetia — Alania. Among these strains, 5 were isolated from diphtheria patients (moderate disease found in one case, mild course — remaining patients) and 7 strains were isolated from bacterial carriers. In two cases C. diphtheriae from diphtheria patients were identified as ST25 sequence type, gravis variant; in one case — ST8 type, gravis variant; two cases — ST67 sequence type, mitis variant. In asymptomatic carriers of tox-positive C. diphtheriae strains they belonged to ST25 sequence type, gravis variant — in two cases, ST67 type, mitis variant — in four cases. A sequencing type was not identified in one case. All sequence types were widespread globally being presented by a large number of isolates in the PubMLST and characterized by a substantial amount of derivative sequence types. At the same time, they belonged to different clonal complexes and differed markedly from each other contributing to their reliable difference as assessed by MLST. Study of gene dtxR sequence diversity showed that all allelic variants were typical for the representatives of these sequence types. New alleles of gene dtxR were not revealed in strains examined. It was shown that non-synonymous substitution C440T leading to A147V amino acid substitution was found solely in one allele distributed in ST8, ST185, ST195 and ST451 types suggesting at late mutation. In contrast, the polymorphism C640A resulting in the amino acid substitution L214I was found not only in the same allele, but also in the basal tree branches indicating that isoleucine was in the ancestral sequence of the protein