Experimental study of the thermal stability of materials in high temperature oxygen-containing media

An experimental study is made of the interaction of several materials with a high temperature medium containing oxygen. The temperature of the surface was measured as a function of time. It is found that the higher the velocity of mass removal from the surface, the more effective is the material from the viewpoint of heat resistance

Evidence for Escherichia coli DcuD carrier dependent FOF1-ATPase activity during fermentation of glycerol

During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work reveals the total and N,N’-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5 in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40% and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD is absent. No significant differences were determined in wild type and mutants specific growth rate except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact on H+ fluxes, FOF1-ATPase activity and depends on potassium ions

Transformation of students’ perceptions of disability as a result of inclusive education: a posse ad esse

Introduction. The relevance of the research is determined by the necessity to fill knowledge gaps related to understanding the socio-cultural transformations taking place in the student environment due to the extensive development of inclusive technologies in universities. Aim. The present research aimed to identify transformations in the public consciousness of students associated with the period of application of the inclusive approach and to determine the factors that determine them. Methodology and research methods. The study relies on the theoretical and methodological concept of constructing a metasystem “personality – group – society” in the context of an individual assimilating social experience. In determining the empirical basis of the study, the principle of unity and differentiation was applied to identify potential causal relationships between the socio-demographic characteristics of respondents and the development of predominant sentiments regarding the resolution of integration issues in society for individuals with disabilities. A comparison of the semantic dominants of the attitudes towards disabled students, who studied in 2008 (at the initial stage of awareness of the need for an inclusive approach) and in 2023 (at a mature stage characterised by many years of experience in ensuring a barrier-free educational environment in universities), allowed the authors to identify a number of fundamental socio-cultural characteristics of modern students for further qualitative research. Results. The research outcomes revealed that there have been no qualitative changes in the public consciousness of modern students regarding people with disabilities, despite the extensive development of inclusion in universities. Additionally, there are still persistent manifestations of stigmatisation of students with health problems. The negative impact of overestimating the effect of administrative factors on the inclusive process, on the one hand, and ignoring the need to support the development of social values in the student’s personality, on the other, was revealed. Scientific novelty. The research contributes to the development of scientific reflection methods in line with the phenomenological approach and clarifies the subject area of studying inclusive processes in universities. Practical significance. The presented materials and conclusions may be of scientific and practical interest to both researchers and organisers of inclusive processes in universities.Введение. Актуальность исследования обусловлена необходимостью восполнения пробелов в знаниях, связанных с осмыслением социокультурных трансформаций, происходящих в университетской среде вследствие экстенсивного развития инклюзивных технологий в вузах. Цель исследования – выявление связанных с периодом применения инклюзивного подхода трансформаций в общественном сознании студентов и определение обуславливающих их факторов. Методология, методы и методики. Исследование опирается на теоретико-методологическое представление о построении метасистемы «личность – группа – общество» в контексте усвоения личностью социального опыта. При определении эмпирической базы исследования был применен принцип единства и дифференциации с целью выявления возможных причинно-следственных связей между социально-демографическими характеристиками респондентов и формированием доминирующих настроений по отношению к решению проблем интеграции в обществе людей с инвалидностью. Сопоставление смысловых доминант отношения к инвалидам студентов, обучавшихся в 2008 году (на начальной стадии осознания необходимости применения инклюзивного подхода) и в 2023 году (на зрелой стадии, характеризующейся многолетним опытом обеспечения безбарьерности образовательной среды в вузах), позволило выявить ряд принципиальных для дальнейших качественных исследований социокультурных характеристик современного студенчества. Результаты позволили сделать вывод об отсутствии качественных изменений в общественном сознании современных студентов в отношении инвалидов, несмотря на экстенсивное развитие инклюзии в вузах, и о сохраняющихся проявлениях стигматизации обучающихся с проблемами здоровья. Выявлено негативное влияние переоценки эффекта воздействия административного фактора на инклюзивный процесс, с одной стороны, и игнорирование необходимости поддержки процессов развития общественных ценностей личности студента, с другой. Научная новизна. Исследование вносит вклад в развитие методов научной рефлексии в русле феноменологического подхода и уточняет предметную область изучения инклюзивных процессов в вузах. Практическая значимость. Материалы и выводы настоящей работы могут представлять научно-практический интерес как для исследователей, так и для организаторов инклюзивных процессов в вузах

Neutralization of Botulinum Neurotoxin by a Human Monoclonal Antibody Specific for the Catalytic Light Chain

Background: Botulinum neurotoxins (BoNT) are a family of category A select bioterror agents and the most potent biological toxins known. Cloned antibody therapeutics hold considerable promise as BoNT therapeutics, but the therapeutic utility of antibodies that bind the BoNT light chain domain (LC), a metalloprotease that functions in the cytosol of cholinergic neurons, has not been thoroughly explored. Methods and Findings: We used an optimized hybridoma method to clone a fully human antibody specific for the LC of serotype A BoNT (BoNT/A). The 4LCA antibody demonstrated potent in vivo neutralization when administered alone and collaborated with an antibody specific for the HC. In Neuro-2a neuroblastoma cells, the 4LCA antibody prevented the cleavage of the BoNT/A proteolytic target, SNAP-25. Unlike an antibody specific for the HC, the 4LCA antibody did not block entry of BoNT/A into cultured cells. Instead, it was taken up into synaptic vesicles along with BoNT/A. The 4LCA antibody also directly inhibited BoNT/A catalytic activity in vitro. Conclusions: An antibody specific for the BoNT/A LC can potently inhibit BoNT/A in vivo and in vitro, using mechanisms not previously associated with BoNT-neutralizing antibodies. Antibodies specific for BoNT LC may be valuable components o

Attomolar Detection of Botulinum Toxin Type A in Complex Biological Matrices

BACKGROUND: A highly sensitive, rapid and cost efficient method that can detect active botulinum neurotoxin (BoNT) in complex biological samples such as foods or serum is desired in order to 1) counter the potential bioterrorist threat 2) enhance food safety 3) enable future pharmacokinetic studies in medical applications that utilize BoNTs. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a botulinum neurotoxin serotype A assay with a large immuno-sorbent surface area (BoNT/A ALISSA) that captures a low number of toxin molecules and measures their intrinsic metalloprotease activity with a fluorogenic substrate. In direct comparison with the "gold standard" mouse bioassay, the ALISSA is four to five orders of magnitudes more sensitive and considerably faster. Our method reaches attomolar sensitivities in serum, milk, carrot juice, and in the diluent fluid used in the mouse assay. ALISSA has high specificity for the targeted type A toxin when tested against alternative proteases including other BoNT serotypes and trypsin, and it detects the holotoxin as well as the multi-protein complex form of BoNT/A. The assay was optimized for temperature, substrate concentration, size and volume proportions of the immuno-sorbent matrix, enrichment and reaction times. Finally, a kinetic model is presented that is consistent with the observed improvement in sensitivity. CONCLUSIONS/SIGNIFICANCE: The sensitivity, specificity, speed and simplicity of the BoNT ALISSA should make this method attractive for diagnostic, biodefense and pharmacological applications

A Transcriptional “Scream” Early Response of E. coli Prey to Predatory Invasion by Bdellovibrio

We have transcriptionally profiled the genes differentially expressed in E. coli prey cells when predatorily attacked by Bdellovibrio bacteriovorus just prior to prey cell killing. This is a brief, approximately 20–25 min period when the prey cell is still alive but contains a Bdellovibrio cell in its periplasm or attached to and penetrating its outer membrane. Total RNA was harvested and labelled 15 min after initiating a semi-synchronous infection with an excess of Bdellovibrio preying upon E. coli and hybridised to a macroarray spotted with all predicted ORFs of E. coli. SAM analysis and t-tests were performed on the resulting data and 126 E. coli genes were found to be significantly differentially regulated by the prey upon attack by Bdellovibrio. The results were confirmed by QRT-PCR. Amongst the prey genes upregulated were a variety of general stress response genes, potentially “selfish” genes within or near prophages and transposable elements, and genes responding to damage in the periplasm and osmotic stress. Essentially, the presence of the invading Bdellovibrio and the resulting damage to the prey cell elicited a small “transcriptional scream”, but seemingly no specific defensive mechanism with which to counter the Bdellovibrio attack. This supports other studies which do not find Bdellovibrio resistance responses in prey, and bodes well for its use as a “living antibiotic”

Carbon Dioxide Utilisation -The Formate Route

UIDB/50006/2020 CEEC-Individual 2017 Program Contract.The relentless rise of atmospheric CO2 is causing large and unpredictable impacts on the Earth climate, due to the CO2 significant greenhouse effect, besides being responsible for the ocean acidification, with consequent huge impacts in our daily lives and in all forms of life. To stop spiral of destruction, we must actively reduce the CO2 emissions and develop new and more efficient “CO2 sinks”. We should be focused on the opportunities provided by exploiting this novel and huge carbon feedstock to produce de novo fuels and added-value compounds. The conversion of CO2 into formate offers key advantages for carbon recycling, and formate dehydrogenase (FDH) enzymes are at the centre of intense research, due to the “green” advantages the bioconversion can offer, namely substrate and product selectivity and specificity, in reactions run at ambient temperature and pressure and neutral pH. In this chapter, we describe the remarkable recent progress towards efficient and selective FDH-catalysed CO2 reduction to formate. We focus on the enzymes, discussing their structure and mechanism of action. Selected promising studies and successful proof of concepts of FDH-dependent CO2 reduction to formate and beyond are discussed, to highlight the power of FDHs and the challenges this CO2 bioconversion still faces.publishersversionpublishe

Teacher Professional Development Models and Practices in Foreign Educational Systems

Introduction. The formation and implementation of the national teacher growth system (NTGS) in the Russian Federation involves global practices, which are based on effective teacher professional development models. The present research analyses approaches and models used in the training and continuing professional development of teachers in Hong Kong and Finland.The aim of the current article is to identify the meaningful issues of the formation of a teacher growth national system in the context of the best foreign experiences, as well as to reveal the possibilities, which allow applying these effective experiences to Russian realities.Methodology and research methods. In the course of the study, the authors relied on a socio-cultural approach to the organisation of the additional professional pedagogical education, the concept of continuing and non-formal learning throughout life, as well as methodological approaches and methods developed and applied in comparative pedagogy. Understanding and summarising the content of the research materials was carried out on the basis of a comparative retrospective analysis with a search depth of 10-12 years.Results. The analysis of effective models of teacher professional growth and development in Hong Kong and Finland has revealed the following similar positions: strict selection rules and requirements for teaching major and specialties; expanding the component of teaching practice in the learning process; inclusion of the research-based component in training programmes at university and post-graduate levels of teacher professional development; actualisation of the problems concerning specific groups of teachers; creation of continuing (life-long) teacher professional development systems; awareness of the special relevance of “entry into the profession” programmes as a dynamically developing component in the teacher continuing professional growth; creation of specific motivation mechanisms for successful professional teaching activities, which are based on national historical and cultural characteristics and values.Scientific novelty. The main stages, modules, key characteristics of teacher professional development models in Hong Kong and Finland are analysed systematically. The peculiarities of teacher professional development practices, which are widespread in Anglosphere, are revealed in terms of Hong Kong realities. The motivation mechanisms for effective teacher professional activities, which are based on national cultural and historical values, have been described. The similarities and differences in the application of these mechanisms are demonstrated.Practical significance. The results and conclusions of the research undertaken by the authors can be put into the basis for further reforms aimed at the formation and implementation of the teacher growth national system in the Russian Federation. Also, these research findings have important implications to create the mechanisms for adapting teachers to changes and to increase their motivation for continuing professional growth