73 research outputs found

    Molecular packing, piezo- and pyroelectric properties of tert-butyl N-(tert-butoxycarbonyl)-(S)-prolinamide

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    The work was financially supported by the Russian Foundation for Basic Research (grant no. 16-33-60122). The equipment of the Ural Centre for Shared Use “Modern Nanotechnologies” UrFU and Centre for Joint Use “Spectroscopy and Analysis of Organic Compounds” was used

    Automated morphometric studies of collagen fibers as an auxiliary method for diagnosing cold injury

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    Background. Cold injury is one of the most significant problems for the northern regions of the Russian Federation. Frostbite is defined as a complex of changes caused by the action of low temperatures, which lead to morphological changes in damaged tissue structures. As a result, the skin with underlying tissues and the intercellular matrix, the components of which are collagen fibers, are damaged, which eventually leads to remodeling and a protracted course of the wound process. Morphometric studies in combination with quantitative analysis of microphotographs (histological specimens) using GIS technologies make it possible to distinguish altered collagen fibers under the influence of low temperatures from relatively healthy tissues. The aim of the study. To assess the possibility of using computer analysis of microphotographs in  a  complex of morphometric studies of collagen fibers in local cold injury. Materials and methods. The study included 84 patients with III and IV degree frostbite of the lower extremities. Morphological study of tissues and microphotography were performed using Leica DM2500 microscope (Leica, Germany). The thickness of  collagen fibers was measured based on  visual measurements of characteristic areas of the microphotograph. Computer analysis of tissue microphotographs of  the  zone of cryoinjury was performed using the ArcINFO software (Esri, USA). Statistical processing of the study results was carried out using the SPSS Statistics software package (IBM Corp., USA). Graphs and diagrams were constructed using MS Office Excel (Microsoft Corp., USA). Results. With frostbite, severe tissue damage occurs, accompanied by the destructive processes of the extracellular matrix components. Low temperatures contribute to  changes in the width and orientation of collagen fibers in the damaged area. In  this  regard, a change in the texture of the histological specimen image leads to achange in the numerical characteristics of the standard deviation of the curvature coefficient in the studied area of the microphotograph. Thus, in the late reactive period, the described complex of morphometric studies makes it possible to classify particular microphotograph as having pathological signs or as a sample of healthy tissue

    ОСОБЕННОСТИ ПРОБОПОДГОТОВКИ ПРИ ОПРЕДЕЛЕНИИ ФЕНОЛА В ВЫСОКОЦВЕТНЫХ ПРИРОДНЫХ ВОДАХ МЕТОДОМ ГАЗОВОЙ ХРОМАТОГРАФИИ

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    Existing the phenol determination methods in water suggest the use of extraction concentration combined with heating the sample and phenol derivatization in alkaline media. It is shown that humic substances of water samples is destructed by the alkaline solutions or heating. Humic substances destruction produces phenol and distorts the results of quantitative chemical analysis. The interfering effect of humic substances need to be eliminate in beginning of the analytical cycle. A method for removing humus by coagulation on the Al2O3 layer with simultaneous impregnation of the sorbent with copper (II) cations is proposed. The method allows to eliminate the interfering effect of humic substances in the phenol quantification in natural waters. The conditions of humic substances complete removal from the water samples is established, the role of copper (II) cations in this process is shown. Under optimal conditions, the native phenol adsorption on alumina surface does not exceed 3 %. For selective and sensitive gas-chromatographic determination of phenol in the eluate we used preliminary bromination. Phenol bromoderivative (2,4,6-tribromophenol) with a halogen-selective electron-capture detector was detected. A procedure was developed for phenol determination in water of 0.2 to 10 μg/dm3, the relative error of measurement in this range does not exceed 30 %. The water sample volume is 25 cm3, the analysis duration is 30 min.Keywords: phenol, gas chromatography, high-color natural water, chemical modification, humic substances, aluminum oxideDOI: http://dx.doi.org/10.15826/analitika.2019.23.2.004(Russian)I.V. Gruzdev, B.M. Kondratenok, O.M. Zueva, E.I. Lyu-Lyan-Min Institute of Biology of Komi Scientific Centre of the Ural Branch of the Russian Academy of Sciences (IB Komi SC UB RAS), Kommunisticheskaya st., 28, Syktyvkar, 167982, Russian FederationРяд методик определения фенольных соединений в водных средах предполагает использование в аналитическом цикле экстракционного концентрирования в сочетании с нагреванием пробы и проведение реакций дериватизации в щелочных средах. Показано, что такие операции, проводимые в присутствии гумусовых веществ, вызывают их деструкцию с образованием фенола. Предложен способ удаления гумуса путем коагуляции на слое Al2O3 при одновременном импрегнировании сорбента катионами меди (II). Способ позволяет устранить мешающее влияние гумусовых веществ при количественном определении фенола в природных водах. Установлены условия, при которых достигается полное удаление гумусовых веществ из анализируемой пробы воды, показана роль катионов меди в этом процессе. При установленных оптимальных условиях адсорбция нативного фенола на оксиде алюминия не превышает 3 %. С целью повышения чувствительности и селективности определения фенола в получаемом элюате проводится его химическая модификация в 2,4,6-трибромфенол с последующим газохроматографическим анализом с галогенселективным электронозахватным детектором. Диапазон определяемых концентраций фенола в воде от 0.2 до 10 мкг/дм3 с относительной погрешностью не более 30 %. Объем пробы воды, необходимый для анализа, – 25 см3, продолжительность анализа – 30 минут.Ключевые слова: фенол, газовая хроматография, высокоцветные природные воды, химическая модификация, гумусовые вещества, оксид алюминияDOI: http://dx.doi.org/10.15826/analitika.2019.23.2.00

    Исследование антиоксидантного эффекта митохондриально-направленного антиоксиданта SkQ1 на модели изолированного сердца крысы

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    Mitochondrially targeted antioxidants based on Skulachev ions (SkQ1) are extremely attractive for neutralizing reactive oxygen species directly in the mitochondrial matrix.The aim was to examine the antioxidant and cardioprotective status of the SkQ1 mitochondrially targeted antioxidant in an isolated rat heart model of ischemia and reperfusion after cold cardioplegia.Material and methods. The effects of different concentrations of SkQ1 (1200 ng/ml, 120 ng/ml, 12 ng/ml) were explored on isolated hearts of Wistar rats (n=50) during 240-min cold cardioplegia. The levels of oxidative stress, changes in myocardial damage markers (classical and highly specific) and cardiac function (coronary flow velocity, heart rate, systolic pressure) were assessed.Results. The use of SkQ1 at 12 ng/ml resulted in a significant neutralization of oxidative stress manifestations (P<0.05). The minimum concentration of NO metabolites (nitrates and nitrites) (36.2 [30.8; 39.8] µmol/ml) was maintained at pre-ischemic level throughout the 30-minute reperfusion period, while the malonic dialdehyde concentration (49.5 [41.1; 58.9] µmol/g) was lower compared with SkQ1 use at 120 ng/ml dose. Due to the «mitigation» of oxidative stress, intracellular enzymes and highly specific markers of myocardial damage rose more slowly during reperfusion, while cardiac function recovery occurred at a higher rate and showed stability upon restoration of perfusion.Conclusion. SkQ1 at 12 ng/ml concentration showed strong antioxidant and cardioprotective properties in an ex vivo study.Митохондриально-направленные антиоксиданты на основе ионов Скулачёва (SkQ1) крайне привлекательны для нейтрализации активных форм кислорода непосредственно в матриксе митохондрий.Цель — изучить антиоксидантный и кардиопротективный эффект митохондриально-направленного антиоксиданта — SkQ1 на модели ишемии и реперфузии изолированного сердца крысы в условиях холодовой кардиоплегии.Материалы и методы. Исследование эффектов SkQ1 (1200 нг/мл, 120 нг/мл, 12 нг/мл) провели на изолированных сердцах крыс линии Wistar (n=50) в условиях 240-минутной холодовой кардиоплегии. Оценили уровень окислительного стресса, динамику маркеров повреждения миокарда (классические и высокоспецифичные) и функцию сердечной мышцы (скорость коронарного протока, частоту сердечных сокращений, систолическое давление).Результаты. Использование SkQ1 в концентрации 12 нг/мл привело к статистически значимой нейтрализации проявлений окислительного стресса (р<0,05): минимальное содержание NO-метаболитов — нитратов и нитритов (36,2 [30,8; 39,8] мкмоль/мл) поддерживалось на доишемическом уровне всю 30-минутную реперфузию, а концентрация малонового диальдегида (49,5 [41,1; 58,9] мкмоль/г) была ниже в сравнении с применением SkQ1 в концентрации 120 нг/мл. Вследствие «смягчения» окислительного стресса внутриклеточные ферменты и высокоспецифичные маркеры повреждения миокарда при реперфузии нарастали медленно, а восстановление сердечной функции произошло более высокими темпами и показало свою стабильность при возобновлении перфузии.Заключение. SkQ1 в концентрации 12 нг/мл проявил выраженные антиоксидантные и кардиопротективные свойства в исследовании ex vivo

    Piezoelectric properties of the crystals of ortho-carboranyl (S)-phenylalanine and (S)-valine derivatives

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    Piezoelectric response of the crystals of carborane-containing pseudo-dipeptides was measured using the piezoresponse force microscopy. Observable piezocoefficients of the crystals reached 76.2 pC/N. Structure and stereo configuration of compounds affected the piezoelectric response of the crystals.The equipment of Ural Center for Shared Use "Modern Nanotechnology" UrFU has been used. The work was financially supported by Russian Foundation for Basic Research (grant no. 16-33-60122)

    Synthesis of Pyrimidine Conjugates with 4-(6-Amino-hexanoyl)-7,8-difluoro-3,4-dihydro-3-methyl-2H-[1,4] benzoxazine and Evaluation of Their Antiviral Activity

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    A series of pyrimidine conjugates containing a fragment of racemic 7,8-difluoro-3,4-dihydro-3-methyl-2H-[1,4]benzoxazine and its (S)-enantiomer attached via a 6-aminohexanoyl fragment were synthesized by the reaction of nucleophilic substitution of chlorine in various chloropyrimidines. The structures of the synthesized compounds were confirmed by1H,19F, and 13 C NMR spectral data. Enantiomeric purity of optically active derivatives was confirmed by chiral HPLC. Antiviral evaluation of the synthesized compounds has shown that the replacement of purine with a pyrimidine fragment leads to a decrease in the anti-herpesvirus activity compared to the lead compound, purine conjugate. The studied compounds did not exhibit significant activity against influenza A (H1N1) virus. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 19-13-00231-PFunding: This research was funded by the Russian Science Foundation, grant number 19-13-00231-P

    Flow cytometry sorting of cells infected with African swine fever virus

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    The African swine fever panzootic  is continuing  to spread,  and the number  of affected countries and material losses are increasing. In particular, India, Papua New Guinea, Malaysia, Greece and Bhutan joined the list of ASF infected countries in 2020–2021. The disease control is hindered  by the lack of commercially available and effective vaccines, which, in its turn, is attributable  to the insufficient knowledge of ASF pathogenesis  and immune defense against the disease. The use of attenuated virus variants enables a thorough  investigation of the factors influencing the virulence of African swine fever virus and the immune  response  to it. This involves the use of naturally attenuated virus variants, as well as of the variants attenuated by a long-term passaging of the virus in cell cultures. However, virulence heterogeneity characteristic of the ASF virus population, necessitates  the additional selection of infected cells for the virus cloning. Conventional culture-based techniques for virus particle cloning are rather time- and labour-consuming;  it is therefore appropriate  to use flow cytometry cell sorting for the selection and cloning of virus infected cells with a view of selecting  homologous  virus lineages.  The paper  presents  the results of sorting  of African green  monkey kidney cells (CV-1) and porcine bone marrow cells infected with African swine fever virus; the cells were sorted into the 96-well culture plates using a MoFlo  Astrios   EQ cell sorter in order to isolate a population of the virus originating from one infected cell. After the single cell sorting of the infected cell cultures into the 96-well plates, ASF positive cell detection  rates in the plate wells were 30% for porcine bone marrow cells and 20% for CV-1

    Плотность кальцификации при компьютерной томографии в зависимости от параметров сканирования: фантомное исследование

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    Purpose of research. The aim of the study is to evaluate changes in density, Agatston score, Volume and Mass scores of coronary calcium at different scanning parameters using phantom measurement.Materials and methods. 8 1-ml insulin syringes filled with potassium hydroorthophosphate solution of different densities were used in the study. The syringes were placed at regular intervals into two phantoms: type 1 phantom – container filled with water; type 2 phantom – Chest Phantom N1 “LUNGMAN”. The phantoms were scanned with a Philips Ingenuity Elite CT 128 scanner using protocols with different voltages (80, 100, 120, 140 kV), amperage (27–45, 166, 330–400 mA), and slice thickness (0.625, 1, 2.5, 3 mm).Results. Density and Agatston indexes were obtained at different scanning parameters (voltage, amperage, slice thickness) for different factors of calcification density in both phantoms. The results are presented as a table with mean density values, standard deviation (SD), Agatston score of coronary calcium, and scanning parameters.Conclusion. The study demonstrates the influence of various scanning parameters on coronary artery calcium scoring results. The obtained information can be used in practice for more accurate quantification of coronary artery calcium, regardless of the scanning parameters.Цель исследования: оценить на фантомах изменения плотности, индекса Агатстона, объемного коронарного индекса, массы фосфата коронарного кальция при разных параметрах сканирования.Материал и методы. В исследовании использовались 8 инсулиновых шприцев объемом 1 мл, наполненных раствором гидроортофосфата калия, с разными характеристиками плотности. В дальнейшем данные шприцы на равном расстоянии друг от друга были помещены в два фантома: фантом 1-го типа – бокс, заполненный водой, фантом 2-го типа – Chest Phantom N1 “LUNGMAN”. Фантомы были просканированы при помощи компьютерного томографа Philips Ingenuity Elite 128 срезов по протоколам с разным напряжением (80, 100, 120, 140 кВ), силой тока (27–45, 166, 330–400 мА), толщи- ной среза (0,625, 1, 2,5, 3 мм).Результаты. Получены показатели плотности, индекса Агатстона при различных параметрах сканирования (напряжение, сила тока, толщина среза) для разных факторов плотности кальцификации в фантомах 1-го и 2-го типа. Результаты представлены в виде таблицы со средними значениями плотности, стандартным отклонением (SD), индексом Агатстона коронарного кальция и параметрами сканирования.Заключение. Исследование демонстрирует вариабельность показателей факторов коронарного кальция при их оценке на различных параметрах сканирования. Полученную информацию возможно использовать на практике для более точного подсчета коронарного кальция вне зависимости от параметров сканирования

    Author Correction: Federated learning enables big data for rare cancer boundary detection.

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