Rapid one-step biotinylation of biological and non-biological surfaces

We describe a rapid one-step method to biotinylate virtually any biological or non-biological surface. Contacting a solution of biotin-spacer-lipid constructs with a surface will form a coating within seconds on non-biological surfaces or within minutes on most biological membranes including membrane viruses. The resultant biotinylated surface can then be used to interact with avidinylated conjugates, beads, vesicles, surfaces or cells

Ultra-fast Glyco-coating of Non-biological Surfaces

The ability to glycosylate surfaces has medical and diagnostic applications, but there is no technology currently recognized as being able to coat any surface without the need for prior chemical modification of the surface. Recently, a family of constructs called function-spacer-lipids (FSL) has been used to glycosylate cells. Because it is known that lipid-based material can adsorb onto surfaces, we explored the potential and performance of cell-labelling FSL constructs to “glycosylate” non-biological surfaces. Using blood group A antigen as an indicator, the performance of a several variations of FSL constructs to modify a large variety of non-biological surfaces was evaluated. It was found the FSL constructs when optimised could in a few seconds glycosylate almost any non-biological surface including metals, glass, plastics, rubbers and other polymers. Although the FSL glycan coating was non-covalent, and therefore temporary, it was sufficiently robust with appropriate selection of spacer and surface that it could capture anti-glycan antibodies, immobilize cells (via antibody), and withstand incubation in serum and extensive buffer washing, making it suitable for diagnostic and research applications

Analysis of photometric observations of the variable HS 2231+2441

В работе выполнены анализ фотометрических наблюдений и определение параметров молодой предкатаклизмической переменной с sdB-субкарликом, HS 2231+2441. При дифференциальной обработке наблюдений построены кривые блеска объекта в полосах V и R. Их модельный анализ проведен с применением моделей облучаемых звездных атмосфер при совместном учете эффектов отражения и несферичности компонент. В итоге оптимального описания наблюдаемых кривых блеска переопределена часть параметров системы: угол наклона и большая полуось орбиты, радиусы и массы компонент HS 2231+2441. Полученный набор параметров хорошо соответствует современным представлениям о характеристиках подобных систем.The paper analyzes photometric observations and determines the parameters of a young precataclesmic variable with the subdwarf B, HS 2231+2441. During differential processing of observations, the light curves of the object in the V and R bands were constructed. Their model analysis was carried using models of irradiated stellar atmospheres with the combined consideration of the effects of reflection and nonsphericity of the components. As a result of the optimal description of the observed light curves, some of the parameters of the system were redefined: the inclination angle and semi-major axis of the orbit, the radii and masses of the components of HS 2231+2441. The resulting set of parameters is in good agreement with modern ideas about the characteristics of such systems

Antimicrobial resistance of <I>Salmonella</I> isolates recovered from animal products

The article provides data on antimicrobial resistance (AMR) of Salmonella isolates recovered from animal products tested in the Laboratory for Microbiological Testing of the FGBI “ARRIAH” from 2019 to 2020. 106 isolates of Salmonella enterica subsp. Enterica were recovered from 4,500 tested samples of raw materials and products of animal origin, 23% of them wereuntyped, and 77% belonged to 17 serological variants. Isolates of S. enteritidis (n = 37) and S. virchow (n = 9) serovariants dominated among the typed cultures of Salmonella, which is consistent with the data from other authors. Antimicrobial susceptibility of the microorganisms was determined in a disk diffusion test in accordance with the recommendations of the European Committee on Antimicrobial Susceptibility Testing. Different Salmonella serovars demonstrated different proportions of susceptible and resistant isolates, in terms of antibiotics from ten pharmacological groups. The largest number of polyresistant isolates was noted in Salmonella serovars S. virchow, S. nigeria, S. infantis, S. colindale. Both resistant and polyresistant Salmonella isolates were most often isolated from poultry products. S. typhimurium serovar, which is referred to in literature as polyresistant, was resistant to one or two antimicrobial agents as the research demonstrates. Isolates of 9 Salmonella serovars out of 17 (65%) showed resistance to nalidixic acid. 97% (n = 36) of S. enteritid isisolates were resistant to this antimicrobial agent. Isolates of S. Colindale serovar (n = 2) were resistant to 8 antimicrobials, S. papuana (n = 5) – to 6 antibiotics, and S. agona (n = 3) – to 5 antimicrobials. Untyped Salmonella isolates were resistant to 9 antibiotics, 2 cultures out of them showed resistance to ciprofloxacin

Neoglycolipids Micelle-like Structures as a Basis for Drug Delivery Systems

Targeted drug delivery is one of the most promising tasks of nanomedicine, as this is a real way to increase the effectiveness of therapeutic effects against many diseases. In this regard, the development of new inexpensive highly effective stimulating and non-immunogenic drug delivery systems (DDS) is of great importance. In this work new molecular candidates were proposed and studied for the creation of such systems based on the use of new compounds, neoglycolipids. It is shown that these compounds are capable of self-association in aqueous solutions and can serve as potential carriers of drug compounds with targeted delivery determined by their terminal groups (in particular, glycans). The processes of their associates formation and features of their structure are investigated. The results show that these selforganizing nanoscale systems can be used as a basis for developing new drug delivery systems. Keywords: neoglycolipids, micelle-like structures, small-angle X-ray scattering, molecular dynamics simulatio

Features of the ancestral bilaterian inferred from Platynereis dumerilii ParaHox genes

Background The ParaHox gene cluster is the evolutionary sister to the Hox cluster. Whilst the role of the Hox cluster in patterning the anterior-posterior axis of bilaterian animals is well established, and the organisation of vertebrate Hox clusters is intimately linked to gene regulation, much less is known about the more recently discovered ParaHox cluster. ParaHox gene clustering, and its relationship to expression, has only been described in deuterostomes. Conventional protostome models (Drosophila melanogaster and Caenorhabditis elegans) are secondarily derived with respect to ParaHox genes, suffering gene loss and cluster break-up. Results We provide the first evidence for ParaHox gene clustering from a less-derived protostome animal, the annelid Platynereis dumerilii. Clustering of these genes is thus not a sole preserve of the deuterostome lineage within Bilateria. This protostome ParaHox cluster is not entirely intact however, with Pdu-Cdx being on the opposite end of the same chromosome arm from Pdu-Gsx and Pdu-Xlox. From the genomic sequence around the P. dumerilii ParaHox genes the neighbouring genes are identified, compared with other taxa, and the ancestral arrangement deduced. Conclusion We relate the organisation of the ParaHox genes to their expression, and from comparisons with other taxa hypothesise that a relatively complex pattern of ParaHox gene expression existed in the protostome-deuterostome ancestor, which was secondarily simplified along several invertebrate lineages. Detailed comparisons of the gene content around the ParaHox genes enables the reconstruction of the genome surrounding the ParaHox cluster of the protostome-deuterostome ancestor, which existed over 550 million years ago.Publisher PDFPeer reviewe

Метрологическое обеспечение газовых калориметров и анализаторов числа Воббе

The paper describes research on metrological assurance of such measuring instruments as gas calorimeters and Wobbe index analysers. The purpose of the performed research is development of reference materials for gases with certified value of net volume-basis calorific value traceable to Russian state primary standard. Input set of candidate gases is hydrogen, methane, ethane and propane, as well as the target uncertainty of lower volumetric combustion energy value equal to 0,3 % – both were selected basing on results of metrological characteristics analysis of calorimetric equipment. The certified value of lower volumetric combustion energy is traceable to the State Primary Standard of combustion energy, specific combustion energy and volumetric combustion energy units GET 16. The certified value of selected gases and the uncertainty of this value were estimated with usage of comparing calorimeters for the combustion of high- and low-calorie gases «USVG» and «USNG» included in GET 16. Results obtained during investigational study and reference materials characterisation confirmed the stated accuracy. The continuance in prospect may allow development of reference materials for gas imitating mixtures of natural and casing-head gases as well as include Wobbe index in the list of certified characteristics.В статье рассматриваются вопросы метрологического обеспечения средств измерений – газовых калориметров и анализаторов числа Воббе. Цель проведенного исследования – разработка стандартных образцов газов с аттестованным значением низшей объемной энергии сгорания, прослеживаемым к государственному первичному эталону. Исходные чистые газы-кандидаты – водород, метан, этан и пропан, а также целевая неопределенность значения низшей объемной энергии сгорания – 0,3 %, были выбраны на основе результатов анализа метрологических характеристик парка калориметрического оборудования. Аттестованное значение низшей объёмной энергии сгорания прослеживается к государственному первичному эталону единиц энергии сгорания, удельной энергии сгорания и объемной энергии сгорания ГЭТ 16. Аттестованное значение для выбранных газов и его неопределенность были оценены с применением эталонных калориметров-компараторов для сжигания высоко- и низкокалорийных газов «УСВГ» и «УСНГ» из состава ГЭТ 16. Результаты, полученные в ходе экспериментальных исследований и характеризации стандартных образцов, подтвердили заявленные показатели точности. Продолжение исследований позволит в перспективе разработать стандартные образцы газовых смесей-имитаторов природного, попутного и других газов, а также включить число Воббе в список аттестуемых характеристик

Стандартные образцы температуры плавления органических веществ: перспективы разработки

The field of the melting point measurements of high-purity organic substances today includes a large number of measuring instruments used in the field of medicine, biology, and the production of perfumery and cosmetic products.The purpose of the research is to identify the features and justify approaches to the development of melting point certified reference materials of organic substances provided with metrological traceability to the SI base measurement units «temperature» (°C).The objectives of the research included justification of the choice of substances-candidates for CRMs; determination of the certification procedure for RMs; establishment of restrictions affecting the certification procedure; estimation of uncertainty for certified values of the melting point CRMs.In the course of the research, a state analysis of metrological assurance in the field of melting point measurements was performed. An overview of the reference complex designed to measure the melting point and purity of organic substances in the range from +40 °C to +250 °C is presented, its functional diagram is given. The basic requirements for substancescandidates for CRMs are identified. The study presents the results of determining the melting point of benzophenone, benzoic acid, succinic acid, anthracene, and caffeine obtained by direct measurements of the phase transition temperature and by indirect measurements based on recording the moment of optical transparency of the substances under study. The results of interlaboratory comparisons on samples of the studied substances are presented, which made it possible to obtain reliable data on the temperature of the emergence of optical transparency at different heating rates. A method for reconciling the results is proposed; it consists in presenting the certified value of the melting point determined by the method of direct measurements of the phase transition temperature in the thermodynamic mode, as well as the certified values of the optical transparency temperature at various heating rates as additional characteristics of the substance in the passports of the developed CRMs. Research objectives for further work are formulated.The theoretical significance of the results obtained lies in the development of theoretical and methodological approaches to the certification of melting point CRMs based on pure organic substances, which make it possible to improve the measurement accuracy in the field of thermal analysis at a higher quality level.Область измерений температуры плавления высокочистых органических веществ на сегодняшний день включает большое количество средств измерений, используемых в сфере медицины, биологии, производства парфюмерно-косметической продукции.Цель данного исследования – выявление особенностей и обоснование подходов к разработке стандартных образцов температуры плавления органических веществ, обеспеченных метрологической прослеживаемостью к основным единицам SI величины «температура» (°C).В задачи исследования входило обоснование выбора веществ-кандидатов на роль СО; определение процедуры аттестации СО; установление ограничений, влияющих на процедуру аттестации; оценка неопределенности для аттестованных значений температуры плавления СО.В ходе исследования выполнен анализ состояния метрологического обеспечения в области измерений температуры плавления. Представлено краткое описание эталонного комплекса, предназначенного для измерений температуры плавления и степени чистоты органических веществ в диапазоне от +40 °C до +250 °C, приведена его функциональная схема. Сформулированы основные требования к веществам –  кандидатам на роль СО. Рассмотрены результаты определения температуры плавления бензофенона, бензойной кислоты, янтарной кислоты, антрацена и кофеина, полученные методом прямых измерений температуры фазового перехода и методом косвенных измерений, основанным на регистрации момента оптической прозрачности исследуемых веществ. Представлены результаты межлабораторных сличительных испытаний на образцах исследуемых веществ, позволившие получить достоверные данные по температуре возникновения оптической прозрачности при различной скорости нагрева. Предложен способ согласования результатов, заключающийся в представлении в паспортах разрабатываемыхСО аттестованного значения температуры плавления, определяемой методом прямых измерений температуры фазового перехода в термодинамическом режиме, а также аттестованных значений температуры оптической прозрачности при различных скоростях нагрева, как дополнительных характеристик вещества. Сформулированы исследовательские задачи для дальнейшей работы.Теоретическая значимость полученных результатов заключается в разработке теоретико-методологических подходов к процедуре аттестации СО температуры плавления на основе чистых органических веществ, позволяющих на более качественном уровне повысить точность проводимых измерений в области термического анализа

Перспективы разработки стандартных образцов числа Воббе

The thermophysical properties of gaseous fuel, including the calorific value and the Wobbe index, are one of its main properties for industrial use. The correctness of measurements of the volumetric energy of gas combustion is currently ensured by using sets of certified reference materials of the lowest volumetric energy of combustion based on pure gases: hydrogen, methane, ethane and propane GSO 11662–2020 / GSO 11665–2020 and gaseous mixtures GSO 11904–2022 / GSO 11907–2022 with metrological traceability to GET 16–2018. However, it becomes necessary to measure the gas relative density to air with established traceability to GET 18–2014 when determining the Wobbe index.The purpose of this research is to improve the accuracy of the pycnometer method for measuring the density of gases for further development and creation of metrological assurance in the field of measuring the Wobbe index.In the course of the research, an analysis of existing methods for determining the gas density was performed, as a result of which the pycnometer method set forth in GOST 17310–2002, GOST 34721–2021 was taken as the basis for the developed method. The uncertainty budget of gas density measurements was estimated using the pycnometer method. It has been established that the mass determination of the gas under study makes the greatest contribution to the total uncertainty. It was decided to increase the internal volume of the pycnometer and use a modified method for determining its volume to minimize the uncertainty.An imitator of a pycnometer with an increased volume was manufactured in an original design to solve the task of developing a modified pycnometer method for measuring the gas density. A gravimetrically produced gaseous mixture of the following composition was chosen for testing the developed method: CO2 –  40.22 mol. %, CH4 –  rest.The theoretical significance of the results obtained lies in approbation of a modified pycnometer method to improve the measurement accuracy of such a gaseous fuel property as the Wobbe index. In the process of developing a modified pycnometer method, the measurement algorithm was tested, the density values of the studied gas were obtained, and the uncertainty budget of density measurements was estimated.The practical significance of the results of this research will expand the possibility of establishing metrological characteristics during the metrological assurance of Wobbe index analyzers, as well as apply the developed method in future accuracy control of the measurement results of the gas relative density to air.Теплофизические параметры газового топлива, в том числе энергия сгорания и число Воббе, являются одними из его основных параметров при использовании в промышленности. Правильность измерений объемной энергии сгорания газов в настоящее время обеспечена применением комплектов стандартных образцов утвержденного типа низшей объемной энергии сгорания на основе чистых газов: водорода, метана, этана и пропана ГСО 11662–2020 / ГСО 11665–2020 и газовых смесей ГСО 11904–2022 / ГСО 11907–2022, имеющих метрологическую прослеживаемость к ГЭТ 16–2018. Однако при определении числа Воббе возникает необходимость измерения относительной плотности газов по воздуху с установленной прослеживаемостью к ГЭТ 18–2014.Целью настоящего исследования является повышение точности пикнометрического метода измерения плотности газов для дальнейшей разработки и создания метрологического обеспечения в области измерений числа Воббе. В ходе исследования проведен анализ существующих методов определения плотности газа, в результате которого в основу разрабатываемой методики был положен пикнометрический метод, изложенный в ГОСТ  17310–2002, ГОСТ 3 4721–2021. Проведена оценка бюджета неопределенности измерений плотности газа пикнометрическим методом. Установлено, что наибольший вклад в суммарную неопределенность вносит определение массы исследуемого газа. Для минимизации неопределенности было решено увеличить внутренний объем пикнометра и использовать модифицированный способ определения его объема.Для решения поставленной задачи по разработке модифицированной пикнометрической методики измерения плотности газов был изготовлен имитатор пикнометра увеличенного объема в оригинальном конструктивном исполнении. Для опробования разрабатываемой методики была выбрана изготовленная гравиметрическим способом газовая смесь следующего состава: СО2 –  40,22 мол. %, СН4 –  ост.Теоретическая значимость полученных результатов заключается в апробации применения модифицированной пикнометрической методики для повышения точности измерений такого параметра газового топлива, как число Воббе. В процессе разработки модифицированной пикнометрической методики опробован алгоритм проведения измерений, получены значения плотности исследуемого газа, проведена оценка бюджета неопределенности измерений плотности.Практическая значимость полученных результатов настоящего исследования позволит расширить возможность установления метрологических характеристик при проведении метрологического сопровождения анализаторов числа Воббе, а также применить разрабатываемую методику в дальнейшем при контроле точности результатов измерений относительной плотности газов по воздуху

A Novel Small Molecule Supports the Survival of Cultured Dopamine Neurons and May Restore the Dopaminergic Innervation of the Brain in the MPTP Mouse Model of Parkinson's Disease

We previously showed that monoterpenoid (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 1 alleviates motor manifestations of Parkinson's disease in animal models. In the present study, we designed and synthesized monoepoxides of (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol 1 and evaluated their biological activity in the MPTP mouse model of Parkinson's disease. We also assessed the ability of these compounds to penetrate the blood-brain barrier (BBB). According to these data, we chose epoxide 4, which potently restored the locomotor activity in MPTP-treated mice and efficiently penetrated the BBB, to further explore its potential mechanism of action. Epoxide 4 was found to robustly promote the survival of cultured dopamine neurons, protect dopamine neurons against toxin-induced degeneration, and trigger the mitogen-activated protein kinase (MAPK) signaling cascade in cells of neuronal origin. Meanwhile, neither the survival-promoting effect nor MAPK activation was observed in non-neuronal cells treated with epoxide 4. In the MPTP mouse model of Parkinson's disease, compound 4 increased the density of dopamine neuron fibers in the striatum, which can highlight its potential to stimulate striatal reinnervation and thus halt disease progression. Taken together, these data indicate that epoxide 4 can be a promising compound for further development, not only as a symptomatic but also as a neuroprotective and neurorestorative drug for Parkinson's disease.Peer reviewe