Spatial beam self-cleaning and supercontinuum generation with Yb-doped multimode graded-index fiber taper based on accelerating self-imaging and dissipative landscape

We experimentally demonstrate spatial beam self-cleaning and supercontinuum generation in a tapered Ytterbium-doped multimode optical fiber with parabolic core refractive index profile when 1064 nm pulsed beams propagate from wider (122 µm) into smaller (37 µm) diameter. In the passive mode, increasing the input beam peak power above 20 kW leads to a bell-shaped output beam profile. In the active configuration, gain from the pump laser diode permits to combine beam self-cleaning with supercontinuum generation between 520-2600 nm. By taper cut-back, we observed that the dissipative landscape, i.e., a non-monotonic variation of the average beam power along the MMF, leads to modal transitions of self-cleaned beams along the taper length

About optimal loss function for training physics-informed neural networks under respecting causality

A method is presented that allows to reduce a problem described by differential equations with initial and boundary conditions to the problem described only by differential equations. The advantage of using the modified problem for physics-informed neural networks (PINNs) methodology is that it becomes possible to represent the loss function in the form of a single term associated with differential equations, thus eliminating the need to tune the scaling coefficients for the terms related to boundary and initial conditions. The weighted loss functions respecting causality were modified and new weighted loss functions based on generalized functions are derived. Numerical experiments have been carried out for a number of problems, demonstrating the accuracy of the proposed methods.Comment: 25 pages, 7 figures, 6 table

Bacterial Degradation of PCB 70 and its Hydroxy Derivatives is an Environmentally Friendly Way to Destroy Pops

One of the problems of our time is the environmentally safe destruction of polychlorinated biphenyls (PCBs) and their hydroxylated derivatives. The aim of the study was to investigate the features and prospects of the decomposition of PCB 70 (2,5,3’,4’-tetrachlorobiphenyl) and hydroxylated chlorobiphenyls derived from it by Rhodococcus wratislaviensis strain CH628. As a result of the application of methods of periodic cultivation, gas chromatography and light spectrometry, it was found that the efficiency of destruction of PCB 70 1 g of cells of strain CH628 was 90 mg PCB/day, and the same indicator for a mixture consisting of hydroxy derivatives obtained from PCB 70 was 56 mg PCB/day. It was shown that the strain uses all components of the mixture of hydroxy-PCB 70 as a growth substrate, but with different degradation rates. When cultivated in a mineral medium with PCB 70 or a mixture of hydroxy-PCB 70, strain CH628 forms biofilms. The analysis of the obtained results shows that the use of the Rhodococcus wratislaviensis CH628 strain will make it possible to develop a technology for the environmentally safe destruction of PCB 70 and hydroxy-PCBs derived from it

Склеродерма-панникулит: взгляд ревматолога

Difficulties in diagnosis and therapy of scleroderma-panniculitis (S-PN), one of the variants of the septal PN, are discussed. Feasibility of ultrasonography, magnetic resonance imaging of soft tissues and histological examination of the lesions in order to set the diagnosis of PN in time is considered. The clinical case of S-PN combined with antiphospholipid syndrome is presented.В статье обсуждаются трудности диагностики и терапии склеродермы-панникулита (С-Пн), одного из вариантов септального Пн. Рассматривается целесообразность использования УЗИ, магнитно-резонансной томографии мягких тканей и гистологического исследования уплотнений с целью своевременного выявления Пн. Представлено клиническое наблюдение сочетания С-Пн и антифосфолипидного синдрома

The effectiveness of combination of 7% hypertonic saline and 0.1% natrii hyaluronas in patients with chronic obstructive pulmonary disease who have suffered a new coronavirus infection

Introduction. New coronavirus infection (COVID-19) contributes to the aggravation of respiratory symptoms in patients with COPD, including affecting the intensity and nature of cough. Hypertonic solution (HS) has a positive effect on the rheological properties of sputum and mucociliary clearance. However, there are no studies in the available literature on the use of HS in patients who have undergone COVID-19.Goal. To evaluate the effect of the combination of 7% hypertonic saline and 0.1% natrii hyaluronas on the intensity and productive nature of cough in patients with COPD who have undergone a new coronavirus infection and the safety of its use in this cohort of patients.Materials and methods. 50 patients with severe COPD in remission who suffered a new coronavirus infection were examined. The rehabilitation stage of treatment was carried out in the conditions of the pulmonology department. From the moment of receiving the last negative PCR result for SARS-CoV-2 to admission to the hospital for rehabilitation, it took from 2 to 3 weeks. The duration of follow-up of patients was 10 days. The patients were divided into two groups: group 1 (n = 25) – patients who received combination of 7% hypertonic saline and 0.1% natrii hyaluronas 7% by inhalation through a nebulizer; group 2 (n = 25) – patients who did not receive combination of 7% hypertonic saline and 0.1% natrii hyaluronas. The severity of cough was assessed (cough severity scale; shortness of breath, cough and sputum scale), clinical and biochemical blood tests, ECG, spirometry.Results. In patients treated with combination of 7% hypertonic saline and 0.1% natrii hyaluronas, a significant decrease in the severity of cough, the amount of sputum was revealed. The tendency to reduce shortness of breath and improve the quality of life is determined. No serious adverse events were detected when using the drug.Conclusions. The use of the combination of 7% hypertonic saline and 0.1% natrii hyaluronas in patients with COPD who have suffered a new coronavirus infection at the rehabilitation stage leads to a decrease in the intensity of cough and improved sputum discharge, which helps to reduce the severity of shortness of breath and improve the quality of life. The use of the drug is safe and does not lead to clinically significant adverse events

Synthesis and biological evaluation of novel carboxylate phosphabetaines derivatives with long alkyl chains

© 2016 Taylor & Francis Group, LLC.The purpose of the present study was to investigate the antibacterial activity of novel alkyl esters of carboxylate phosphabetaine: β-(carboxyalkyl)ethyltributylphosphonium bromides 4–8. The in vitro microbiological activity of the synthesized phosphonium bromides against gram-positive, gram-negative bacteria and the yeast Candida albicans was determined in comparison to standard agents. Microbiological results indicate the synthesized phosphonium salts possess a broad spectrum of activity against the testedmicroorganisms. Every newly synthesized compound was characterized by elemental analyses, IR, 1H NMR, 31P NMR spectral studies

Комплексный подход к определению состава факторов, влияющих на величину энергопотребления при внедрении систем оперативного контроля энергоэффективности

Дана стаття присвячена питанням вдосконалення підходів визначення чинників, які суттєво впливають на величину витрати енергії при здійснені відповідних технологічних процесів. Зокрема, проаналізовано необхідність визначення чинників, від яких залежить величина споживання палива та енергії на будь-якому виробничому об’єкті. Розглянуто методи математичного моделювання, які можуть бути застосовані для встановлення «Стандарту» енергоспоживання в системах оперативного контролю енергоефективності. Виконано порівняння наведених методів визначення чинників, які впливають на величину витрати енергії при здійснені відповідних технологічних процесів.This article is devoted to issues of improvement approaches determine the factors that significantly affect the amount of energy expended in making the relevant processes. In particular, analyzes need to identify factors that affect the value of fuel and energy to any production facility. A review of the methods of mathematical modeling, which can be appilied for the establishment of "standard" energy consumption on the systems of planning and control of energy consumption. A comparison of the above methods for determining the factors that affect the amount of energy expended in making the relevant processes.Данная статья посвящена вопросам совершенствования подходов определения факторов, которые существенно влияют на величину расхода энергии при осуществлении соответствующих технологических процессов. В частности, проанализирована необходимость определения факторов, от которых зависит величина потребления топлива и энергии на любом производственном объекте. Рассмотрены методы математического моделирования, которые могут быть применены для установления «Стандарта» энергопотребления в системах оперативного контроля энергоэффективности. Выполнено сравнение приведенных методов определения факторов, влияющих на величину расхода энергии при осуществлении соответствующих технологических процессов

Nonlinear beam cleanup in Yb-doped GRIN multimode fiber taper

We demonstrate beam self-cleaning in a tapered Ytterbium-doped graded- index multimode fiber in both active and passive configurations, without accompanying self-phase modulation induced spectral broadening or frequency conversio

Септальный панникулит как проявление COVID-19: собственные данные

Objective: to study the clinical and laboratory features of erythema nodosum (EN) in a cohort of patients with COVID-19 referred to a rheumatological center.Patients and methods. During 2020–2021 years 21 patients (18 women and 3 men, mean age 43.2±11.4 years) with EN and polyarthralgia/arthritis were examined. Depending on the time of EN and articular syndrome associated with COVID-19 development, patients were divided into three groups: 1) up to 4 weeks – acute COVID (symptoms potentially associated with infection); 2) from 4 to 12 weeks – ongoing symptomatic COVID and 3) more than 12 weeks – post-COVID syndrome (persistent symptoms not associated with an alternative diagnosis). All patients underwent a comprehensive clinical, laboratory and instrumental examination, including ultrasound of the joints and chest computed tomography (CT), as well as pathomorphological examination of skin and subcutaneous adipose tissue from the site of the node (in 9 cases). Results and discussion. Based on the anamnesis data, COVID-19 in the study cohort had mild (in 13 patients) and moderate (in 8) severity. Two patients (21 years old and 23 years old) with mild severity of the disease noted red painful (45 mm on the visual analogue scale of pain) nodes on the legs and polyarthralgia for the first time on the 2nd – 3rd day from respiratory symptoms onset. In 9 (52.3%) patients, mainly with a mild course, similar skin changes were detected 24.5±7.6 days after active COVID-19 relieve, i.e. during the period of ongoing symptomatic COVID. In 8 (38%) patients, including 6 with moderate severity of the disease, the appearance of nodes was noted after 85.6±12.3 days, which corresponded to the post-COVID syndrome.At the time of examination, complaints of skin rashes and joint pain were reported in 100 and 71.4% of patients, respectively. 67% of patients had shortness of breath, weakness, cough, sweating and myalgia. Subfebrile fever had 5 (24%) patients, mainly with ongoing symptomatic COVID (3 patients). In the overwhelming majority of cases (86%), EN was located on the anterior and lateral surfaces of shins, less often on the posterior and medial surfaces. It is noteworthy that the affection of more than 50% of the surface of the lower and upper extremities was associated with the number of nodes (p<0.02), the level of CRP (p<0.03) and the presence of post-COVID syndrome (p<0.2). Fifteen (71.4%) patients had arthralgias, mainly of ankle (80%) and knee (53.3%) joints.Laboratory abnormalities included: median ESR was 34 [12; 49] mm/h, CRP level – 9 [2; 32] mg/l. The results of the polymerase chain reaction for SARS-CoV-2 were negative in all patients. In 100% of cases IgG antibodies to SARS-CoV-2 were detected and in 52.3% – IgM antibodies. On chest CT 5% lung affection was detected in 43% of patients, 5–25% lesion in 57.1% of patients, 8 (38%) of whom were with post-COVID syndrome. Pathomorphological examination of the nodes showed signs of septal panniculitis.Conclusion. When EN, associated with SARS-CoV-2 appears it is important to suspect a post-infectious manifestation in time, based on the clinical picture of the disease and to determine the scope of further examination and adequate treatment.Цель исследования – изучить клинические и лабораторные особенности узловатой эритемы (УЭ) в когорте больных COVID-19, направленных в ревматологический центр.Пациенты и методы. В течение 2020–2021 гг. исследован 21 пациент (18 женщин и 3 мужчины, средний возраст 43,2±11,4 года) с УЭ и полиартралгиями/артритами. В зависимости от времени развития УЭ и суставного синдрома, ассоциированных с COVID-19, пациенты были разделены на три группы: 1) до 4 нед – острый COVID (симптомы, потенциально связанные с инфекцией); 2) от 4 до 12 нед – продолжающийся симптоматический COVID и 3) более 12 нед – постковидный синдром (сохраняющиеся стойкие симптомы, не связанные с альтернативным диагнозом). Всем пациентам проводили комплексное клинико-лабораторное и инструментальное обследование, включая УЗИ суставов и компьютерную томографию (КТ) органов грудной клетки, а также (в 9 случаях) патоморфологическое исследование биоптатов кожи и подкожной жировой клетчатки из области узла.Результаты и обсуждение. На основании данных анамнеза СOVID-19 в исследуемой когорте имел легкую (у 13 пациентов) и среднюю (у 8) степень тяжести. Двое больных (21 года и 23 лет) с легкой степенью тяжести заболевания на 2-е – 3-и сутки развития респираторного симптома впервые отметили красные болезненные (45 мм по визуальной аналоговой шкале) узлы на голенях и полиартралгии. У 9 (52,3%) пациентов, преимущественно с легким течением, аналогичные изменения кожи выявлены через 24,5±7,6 сут после купирования активного СOVID-19, т. е. в период продолжающегося симптоматического COVID. У 8 (38%) пациентов, в том числе у 6 со средней степенью тяжести болезни, узлы возникали через 85,6±12,3 сут, что соответствовало постковидному синдрому.На момент осмотра жалобы на кожные высыпания и боль в суставах предъявляли 100 и 71,4% пациентов соответственно. Одышка, слабость, кашель, потливость и миалгии беспокоили 67% больных. Повышение температуры тела до субфебрильной наблюдалось у 5 (24%) пациентов, преимущественно при продолжающемся симптоматическом COVID (3 больных). В подавляющем большинстве случаев (86%) УЭ располагалась на передней и латеральной поверхностях голеней, реже – на задней и медиальной поверхностях. Примечательно, что поражение более 50% поверхности нижних и верхних конечностей ассоциировалось с количеством узлов (р<0,02), уровнем СРБ (р<0,03) и постковидным синдромом (р<0,2). У 15 (71,4%) больных имелись признаки артралгий, преимущественно голеностопных (80%) и коленных (53,3%) суставов.При лабораторном исследовании медиана СОЭ составила 34 [12; 49] мм/ч, уровня СРБ – 9 [2; 32] мг/л. Результаты полимеразной цепной реакции на SARS-CoV-2 были негативными у всех пациентов. В 100% случаев выявлены антитела IgG и в 52,3% – IgM к вирусу SARS-CoV-2. При КТ органов грудной клетки 5% поражения легких определялось у 43% больных, от 5 до 25% – у 57,1%, из них у 8 (38%) больных с постковидным синдромом. При патоморфологическом исследовании узлов отмечены признаки септального панникулита.Заключение. При развитии УЭ, ассоциированной с SARS-CoV-2, важно вовремя заподозрить постинфекционное проявление на основании клинической картины заболевания и определить объем дальнейшего обследования и адекватное лечение