Magnetic-field dependence of the critical currents in a periodic coplanar array of narrow superconducting strip

We calculate the magnetic-field dependence of the critical current due to both geometrical edge barriers and bulk pinning in a periodic coplanar array of narrow superconducting strips. We find that in zero or low applied magnetic fields the critical current can be considerably enhanced by the edge barriers, but in modest applied magnetic fields the critical current reduces to that due to bulk pinning alone.Comment: 23 pages, 7 figure

Experience of working with talented children within the Urals project shift — 2018

This article concerns the experience of project-oriented teaching talented children within the Urals project shift in the medical field of science.В статье рассматривается опыт проектно-ориентированной работы с талантливыми детьми в рамках Уральской проектной смены по медицинскому направлению

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

The morphofunctional and biochemical characteristics of opisthorchiasis-associated cholangiocarcinoma in a Syrian hamster model

The validity of experimental models of pathologies is one of the key challenges in translational medicine. Cholangiocarcinoma, or bile duct cancer, ranks second among oncological diseases of the liver. There is a strong association between bile duct cancer and parasitic infestation of the liver caused by trematodes in the family Opisthorchiidae. We have recently demonstrated that cholangiocarcinoma can develop in Syrian hamsters (Mesocricetus auratus) infected by Opisthorchis felineus and administered with dimethylnitrosamine. However, there is still no description of how this experimental model can possibly be used in translational research. The aim of this work was to study the morphological, functional and biochemical characteristics during cholangiocarcinoma development in Syrian hamsters infected by O. felineus and administered with dimethylnitrosamine. The experi­ment lasted 30 weeks with combined exposure to dimethylnitrosamine in drinking water at a dose of 12.5 ppm and a single injection of 50 metacercariae O. felineus. It was shown that the development of cholangiocarcinoma (18 weeks) increased the total number of basophils, eosinophils and monocytes, the relative number of granulocytes, the amount of total and direct bilirubin, and cholesterol and ALT levels, but reduced the relative number of lymphocytes. Based on pathological, morphometric and biochemical analyses, our model has characteristics similar to those in patients with opisthorchiasisassociated cholangiocarcinoma. Thus, this model can be used to test anticancer drugs, to study the mechanisms of cholangiocarcinogenesis and to search for molecular markers for early diagnosis of bile duct cancer

Fecal microbiome change in patients with ulcerative colitis after fecal microbiota transplantation

Intestinal human microbiota is a dynamic system that is under the pressures of its host organism and external factors. Microbiota disruption caused by these factors can lead to severe diseases including inflammatory and oncological diseases of the gastrointestinal tract. One of the possible approaches in managing the intestinal microbiota is fecal microbiota transplantation (FT) – transfer of the microbiota from the stool of a healthy donor to the intestinal tract of a recipient patient. Currently, this procedure is recognized as an efficacious method to normalize the intestinal microbiota mainly in inflammatory diseases of the gastrointestinal tract. In Russia, pilot studies of the effectiveness of FT in patients with ulcerative colitis have been conducted for several years, and these studies were started in Novosibirsk. The aim of this study was to assess the change of intestinal microbiome in 20 patients with ulcerative colitis after a single FT procedure. The main method is a comparative analysis of 16S ribosomal RNA sequence libraries constructed using fecal samples obtained from patients with ulcerative colitis before and after FT and sequenced on the Illumina MiSeq platform. The obtained results showed that FT led to an increase in average biodiversity in samples after FT compared to samples before FT; however, the difference was not significant. In the samples studied, the proportion of Firmicutes sequences, the major gastrointestinal microbiota of healthy people, was decreased (~32 % vs. >70 %), while the proportion of Proteobacteria sequences was increased (>9 % vs. <5 %). In some samples collected before FT, sequences of pathogenic Firmicutes and Proteobacteria were detected, including Acinetobacter spp., Enterococcusspp., Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Stenotrophomonas maltophylia, Streptococcusspp. In most cases, the proportion of such sequences after FT substantially decreased in appropriate samples. The exception was the Clostridiumdifficilesequences, which accounted for <0.5 % of the sequences in samples from almost half of the patients and after FT, the share of such C. difficilesequences was significantly reduced only in samples from three patients. It should be noted that the proportion of Lactobacillusspp. increased ten-fold and their species composition significantly expanded. According to the obtained results, a preliminary conclusion can be made that even a single FT procedure can lead to an increase in the biodiversity of the gastrointestinal microbiota in patients and to the optimization of the taxonomic composition of the microbiota

Social Network-Based Digital Stroke Prevention: Opportunities, Results and Prospects

Aim. To study the possibilities and limitations of the social network as a digital medical tool, which is aimed at improving programs for primary and secondary stroke prevention in young people.Material and methods. The study was carried out in the format of online training for volunteers. At the first stage of the work, the online school “Stroke in Young People” was announced in 8 medical blogs. As part of the school, a special account was created for readers (n=1354). At the second stage, 49 respondents (4% of men, whose average age was 24.4±5.2 years) were selected from 1354 listeners, who were surveyed on “Awareness of risk factors and stroke symptoms among users of social networks” before and after the online school.Results. The online school audience is predominantly female (91%), and 43% of readers were in the 25-34 age group. The total number of people who listened to and read the online school material is 8712 people. 17% worked in the healthcare system, and 22% of respondents had a history of stroke. 38 (78%) people of the 2nd stage among the respondents independently searched for information about stroke earlier, and 30 (61%) received this information passively from medical workers in 2020. Before the online school start, the majority of respondents (over 60%) were aware of 2 out of 7 stroke risk factors (dyslipidemia and arterial hypertension) and 3 out of 6 stroke signs (drooping of the face half, weakness in the limbs and difficulty speaking). Less than 40% of the participants considered the stroke risk factors for diabetes mellitus, other cardiovascular diseases (CVD), obesity, and alcohol use; less than 20% were aware of stroke symptoms such as impaired vision and coordination and very severe headache. After completing online learning, the greatest increase in knowledge was found among the following risk factors – smoking and other CVDs (p<0.05); stroke symptoms - headache and drooping of the face half (p<0.05).Conclusion. The online school aroused interest among healthcare workers and people without medical education, including those with stroke. Most of the respondents believed that they knew how to prevent a stroke (over 80%) and would be able to provide first aid to a person with a stroke (over 90%). At the same time, the awareness of risk factors and stroke symptoms was low prior to the start of learning, even though the study included healthcare workers and stroke survivors. Online learning has led to increased awareness of some risk factors and stroke symptoms. Social media can be one of the tools for medical prevention of stroke in young people, but program planning should take into account the way the material is presented and its readability

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

Clinical and morphological assessment of buccal epithelium in chronic gingivitis

The aim of this work is to evaluate the clinical and cytological significance of buccal epithelium research in chronic gingivitis (CG). 27 patients with CG and 40 healthy volunteers were examined. Buccal cytology was studied before treatment. The cytological abnormalities were evaluated and the apoptosis index and cytogenetic index were calculated. The apoptosis index in CG patients was decreased. The diagnostic sensitivity of this laboratory trait is 76%, and the diagnostic specificity is 75%. The cytogenetic index did not change significantly. The study revealed the features of the buccal epithelium in chronic gingivitis. Comparing these data with the previously studied cytological changes in buccal epithelium in chronic generalized periodontitis, we can formulate an assumption about the mechanisms of progression of periodontal pathology.С целью оценить клинико-цитологическое значение исследования буккального эпителия при хроническом гингивите (ХГ) было обследовано 27 пациентов с ХГ и 40 практически здоровых добровольцев. Исследована буккальная цитограмма до начала лечения. При подсчёте 1000 клеток оценивали цитологические аномалии и рассчитывали интегральные индексы. Количество двуядерных клеток несколько снижалось, а активность апоптоза повышалась в сравнении с контрольной группой (р<0,05). Диагностическая чувствительность данного лабораторного признака — 76%, диагностическая специфичность — 75%. Индекс апоптоза и цитогенетический индекс существенно не менялись. Исследование позволило выявить особенности состояния буккального эпителия при хроническом гингивите. Сопоставляя эти данные с изученными ранее цитологическими изменениями буккального эпителия при хроническом генерализованном пародонтите можно сформулировать предположение о лабораторном мониторинге прогрессирования патологии пародонта

An OBSL1-Cul7Fbxw8 Ubiquitin Ligase Signaling Mechanism Regulates Golgi Morphology and Dendrite Patterning

The elaboration of dendrites in neurons requires secretory trafficking through the Golgi apparatus, but the mechanisms that govern Golgi function in neuronal morphogenesis in the brain have remained largely unexplored. Here, we report that the E3 ubiquitin ligase Cul7Fbxw8 localizes to the Golgi complex in mammalian brain neurons. Inhibition of Cul7Fbxw8 by independent approaches including Fbxw8 knockdown reveals that Cul7Fbxw8 is selectively required for the growth and elaboration of dendrites but not axons in primary neurons and in the developing rat cerebellum in vivo. Inhibition of Cul7Fbxw8 also dramatically impairs the morphology of the Golgi complex, leading to deficient secretory trafficking in neurons. Using an immunoprecipitation/mass spectrometry screening approach, we also uncover the cytoskeletal adaptor protein OBSL1 as a critical regulator of Cul7Fbxw8 in Golgi morphogenesis and dendrite elaboration. OBSL1 forms a physical complex with the scaffold protein Cul7 and thereby localizes Cul7 at the Golgi apparatus. Accordingly, OBSL1 is required for the morphogenesis of the Golgi apparatus and the elaboration of dendrites. Finally, we identify the Golgi protein Grasp65 as a novel and physiologically relevant substrate of Cul7Fbxw8 in the control of Golgi and dendrite morphogenesis in neurons. Collectively, these findings define a novel OBSL1-regulated Cul7Fbxw8 ubiquitin signaling mechanism that orchestrates the morphogenesis of the Golgi apparatus and patterning of dendrites, with fundamental implications for our understanding of brain development