Hanbury Brown and Twiss interferometry at a free-electron laser

We present measurements of second- and higher-order intensity correlation functions (so-called Hanbury Brown and Twiss experiment) performed at the free-electron laser (FEL) FLASH in the non-linear regime of its operation. We demonstrate the high transverse coherence properties of the FEL beam with a degree of transverse coherence of about 80% and degeneracy parameter of the order 10^9 that makes it similar to laser sources. Intensity correlation measurements in spatial and frequency domain gave an estimate of the FEL average pulse duration of 50 fs. Our measurements of the higher-order correlation functions indicate that FEL radiation obeys Gaussian statistics, which is characteristic to chaotic sources.Comment: 19 pages, 6 figures, 1 table, 40 reference

Engagement in Online Learning Through the Lens of Adults' Learning Experience

The article aims to critically examine the role of engagement in the study of the educational experiences of adult learners in online learning. The authors highlight the existence of a gap between the nature of adult educational experiences and the lens through which these experiences are studied and evaluated. This lens is the learners' engagement. The authors highlight the complexity of the construct of learner engagement and point out the inadequacy of assessing it solely through behavioral markers. The theoretical framework of the article is the Community of Inquiry (CoI) model for studying the educational experiences of learners in the digital environment, based on the notion of the socially constructed nature of learning. The article shows how the idea of lifelong learning as the formation of a new professional identity of adults is consistent with the idea of an ontological turn in education. By conceptualizing the educational experiences of adults as active participants in the learning process, the authors propose to consider engagement as a characteristic of these experiences. The authors identify external and internal factors of learner engagement. Based on previous research, internal factors are proposed, namely learners’ prior experience, future self-image, and personal goals. External factors are based on the self-determination theory, where the needs for competence and belongingness become particularly salient for engagement in online learning

IR and UV study of reversible water-induced structural transformations of poly(manganese 1,1′-ferrocenediyl-bis(H-phosphinate)) and poly(cobalt 1,1′-ferrocenediyl-bis(H-phosphinate))

© 2018 Elsevier B.V. Recently new flexible and hydrolytically stable metal-organic framework [M(H2O)2(Fc(PHOO)2)·2H2O]n, M = Co has been synthesized by the use of synthetic technique, described earlier for M = Mn [1]. The heating of both complexes leads to elimination of water molecules and in the case of Co complex is accompanied by change of its color from orange to dark blue. The corresponding structural changes are reversible and are reflected in vibrational and electronic absorption spectra. Analysis of IR, Raman and UV–vis spectra of complexes shows the same structures of Mn and Co complexes before and after heating and suggests that both Mn and Co coordination polyhedra undergo reversible changes under heating from octahedral to tetrahedral form with ferrocene part remaining unchanged

Clinical case of primary immunodeficiency: X-linked agammaglobulinemia

Aclinical case ofprimary immunodeficiency state (PIDS) is described: X-linked agammaglobulinemia in the boy of 8 years old. The results of molecular genetic studies: gene btk (ex 1-19) genome version GRCh38.p5, transcript version ENST00000308731 single nucleotide substitution identified с.1027С > Т in homozygous state leading to premature stop codon p.Gln343Ter (p.Q343*). The presented clinical case reflects the low alertness of pediatricians for PIDS. At the same time, a delay in diagnosis and prescription of treatment aggravates the prognosis of the disease course and reduces the quality of the patient life

Synthesis and structure of ferrocenylphosphinic acids

The series of ferrocenylphosphinic acids Fc(P(R)(O)(OH)) (1a-d) and ferrocene-1,1′-diyl-phosphinic acids Fc(P(R)(O)(OH))2 (2a-d) (R = H (a), Me (b), Et (c), Ph (d)) have been obtained and studied using X-ray single crystal diffraction, IR-spectroscopy and quantum chemistry. The intermolecular hydrogen bonding in 1a-d proceeds highly stereoselectively and results in formation of racemic conglomerate of 1d. The formation of inter- and intra-molecular hydrogen bonds for disubstituted acids 2c-d depends on substituent at phosphorus atoms. © 2014 Elsevier B.V. All rights reserved

CHRONOAMPEROMETRIC METHOD FOR DETERMINING ANTIOXIDANT CAPACITY USING IRON COMPLEXES OF DIFFERENT HYDROPHILITY

It has been established in the work that the value of the Fe(II) oxidation current can be taken as an analytical signal and used as a source of information on AOC. The AOC of some antioxidants was determined. The range of analyzed concentrations and the detection limit of the method are established

Functional state of the chewing muscle group in the musculo-articular dysfunction of the temporomandibular joint in patients with chronic generalized periodontitis

This article is devoted to the diagnosis of musculo-articular dysfunction (MSD) of the temporomandibular joint (TMJ) in patients with chronic generalized periodontitis (CGP). The purpose of our work was to study the functional state of the masticatory group of muscles and facial muscles in MSD of the TMJ in patients with CGP. MATERIALS AND METHODS: A clinical examination of 89 patients aged 35-45 years with CHP and MSD was performed. Diagnostic models were studied in the articulator PROTAR (Germany), electromyography was performed. Results: In patients with MSJ, the EMJ significantly changes the electromyographic (EMG) pattern: there appears spontaneous EMG activity of the masticatory muscles and facial muscles during the period of physiological dormancy, the activity of the temporal muscles increases. In the presence of MSD of the TMJ and bruxism in patientsДанная статья посвящена диагностике мышечно-суставной дисфункции (МСД) височно-нижнечелюстного сустава (ВНЧС) у пациентов с хроническим генерализованным пародонтитом (ХГП). Целью нашей работы явилось изучение функционального состояния жевательной группы мышц и мимических мышц при МСД ВНЧС у пациентов с ХГП. Материалы и методы: произведено клиническое обследование 89 пациентов в возрасте 35-45 лет с ХГП и МСД. Изучали диагностические модели в артикуляторе PR0TAR (Германия), проводили электромиографию. Результаты: у пациентов с МСД ВНЧС значительно изменяется злектромиографическая (ЭМГ) - картина: появляется спонтанная ЭМГ-активность жевательных мышц и мимических мышц в период физиологического покоя, повышается активность височных мышц. При наличии МСД ВНЧС и бруксизма у пациентов с ХГП присутствует спонтанная ЭМГ-активность жевательных и мимических мышц в период физиологического покоя

Determination of the Antioxidant Capacity of Compounds of Different Hydrophilicity in the Combined Presence on the Example of Vitamins C and E

Determination of the antioxidant capacity of different hydrophilicity compounds (phyt-amines C and E) was carried out by the potentiometric method using mixed solvents with a surfactant. The Phosphate Buffer-Ethanol and Acetonitrile (3:2) with Triton X-100 selected as promising for analysis

Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity

A series of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines has been synthesized through oxidation reaction of the corresponding 3,6-disubstituted 1,2,4,5-tetrazines bearing amidine fragments. It is shown that the heterocyclic systems obtained can be modified easily at C(3) position in the reactions with aliphatic alcohols and amines. Also, the reactivity of [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines towards CH-active compounds has been studied. The obtained triazolo[1,5-b]annulated 1,2,4,5-tetrazines proved to be active in micromolar concentrations in vitro against filamentous anthropophilic and zooanthropophilic dermatophyte fungi (Trichophyton, Microsporum and Epidermofiton), which cause skin and its appendages (hair, nails) diseases. © 2022 Korotina et al.; licensee Beilstein-Institut.Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2020-777; Ural Branch, Russian Academy of Sciences, UB RASThis work was supported by the Ministry of Education and Science of the Russian Federation (Agreement No. 075-15-2020-777).Analytical studies were carried out using equipment of the Center for Joint Use “Spectroscopy and Analysis of Organic Compounds”, located in Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences. This work was supported by the Ministry of Education and Science of the Russian Federation (Agreement No. 075-15-2020-777)

Portable potentiometric device for determining the antioxidant capacity

Received: 25.11.22. Revised: 12.12.22. Accepted: 12.12.22. Available online: 21.12.22.The open microcell and the microfluidic device were developed for the determination of the antioxidants capacity of various objects.The potentiometric method implemented in the devices allows estimating the AOC of model and multicomponent objects.The relative standard deviation of the AOC in the devices did not exceed 10%.At present, the development of portable devices for the express assessment of the content of biologically active objects, such as antioxidants, is one of the relevant technological problems of modern chemistry, medicine, and engineering. The main advantages of such devices are the simplicity and rapidity of analysis, small volumes of analyte, as well as miniaturization of equipment, making it possible to carry out the on-site analysis and, thus, to take a step towards the personalized medicine. The potentiometric method using the K3[Fe(CN)6]/K4[Fe(CN)6] system, which in the laboratory-scale version proved to be the most accurate, reproducible, and express, was the basis for the developed prototypes of portable devices. In this study, two versions of prototypes of the portable device are proposed, namely, the open microcell with the 0.2 ml volume and the microfluidic device with flow control. The correctness of the antioxidant capacity (AOC) determination in both systems was confirmed by comparing the results of the "introduced-found" method on model solutions of antioxidants and their mixtures with the AOC results obtained in a standard laboratory electrochemical cell. The relative standard deviation did not exceed 10%. The AOC of some beverage industry was determined using the microfluidic device. The correlation coefficient of the results, obtained in the microfluidic device and the laboratory cell, was 0.90, which indicates good data convergence and the possibility of using the potentiometric method implemented in the microfluidic device to assess the AOC of multicomponent objects.The research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program) is gratefully acknowledged