Experimental observation of parametric X-ray radiation directed along the propagation velocity of relativistic electrons in a tungsten crystal

Parametric X-ray radiation (PXR) due to dynamic diffraction of relativistic electrons is experimentally observed at small angles to the propagation velocity of electrons in a tungsten crystal. The specific features of the experimental method are described, and forward PXR reflections from two crystallographic planes of tungsten are reliably measuredyesBelgorod State Universit

Influence of various factors on chemical decomposition of oxyethylated isononylphenols

Oxidative decomposition of difficultly biodegradable nonionic surfactants, oxyethylated phenols with various degrees of oxyethylation (Neonols AF 9-6, 9-10, 9-12), was examined. The initial rate and extent of the oxidation depend on the degree of oxyethylation, anion of the iron salt added, and temperatureye

Parameters of blood short-chain peptides and digestive hydrolases in patients with chronic hepatitis B virus infection

The aim of the study was to examine specifics of changes in the level of stomach- and pancreas-released blood hydrolases in chronic viral hepatitis B and analyze the mechanisms underlying such changes. We assessed serum markers of HBV infection, liver enzymes tests as well as gastric and pancreatic hydrolase level. The patients examined were divided into three groups: control (healthy) and two study groups — HBV post-infection and chronic HBV infection. Patients with HBV post-infection had no significant deviations from normal range for blood level of gastric and pancreatic hydrolases. Patients with chronic HBV infection were found to contain increased blood level of amylase and lipase, which may evidence about increasing pancreatic functional activity and development of covert pancreatitis. At the same time, decline in the concentration of serum pepsinogen-1 below 40 μg/l could indicate about prominently decreased secretion of hydrochloric acid and development of atrophic gastritis, and it was found that the major factor contributing to development of such disorders was the short-chain peptide CCK-8, which utilization declines in patients with chronic HBV infection. CCK-8 can play a pivotal role in inhibiting stimulation of gastric acid secretion and controls gastric acid, plasma gastrin and somatostatin secretion. Cholecystokinin has been found to inhibit acid secretion by activating CCK type A receptors as well as via somatostatin-involving mechanism. The secretion of gastric somatostatin-14 increased by fivefold due to CCK-8 alone, but was blocked by the CCK-A receptor blocker loxiglumide. These data show that CCK-8 directly inhibits acid reactions by stimulating the release of gastric somatostatin indirectly through the CCK-A receptor. Thus, it can be assumed that normally CCK-8 is mainly utilized by the liver, which is altered during chronic hepatitis B resulting in elevated blood CCK-8 concentration. As a consequence, it enhances pancreatic secretion resulting in developing pancreatitis that is paralleled with inhibited gastric secretion and emerged atrophic gastritis

РЕГЕНЕРАТИВНЫЕ ОСОБЕННОСТИ ТКАНИ ПЕЧЕНИ ПОСЛЕ ОСТАНОВКИ КРОВОТЕЧЕНИЯ НЕРАВНОВЕСНОЙ ПЛАЗМОЙ НА 90-е И 180-е СУТКИ (ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ)

Liver damages occur to 17.8% of blunt abdominal trauma cases. Postoperative mortality in liver damage is a high. It amounts to 4–10% in case of stab wounds, to 30.4–35,2% in case of closed injury, to 39.3% in case of concomitant injury. Complete hemostasis without damage to organ parenchyma is needed for liver surgical operation.The aim of research is to evaluate the regenerative characteristics of liver tissue after hemostasis by nonequilibrium plasma in a long-term period.Material and methods. Research was performed on 20 laboratory rats, 3 experimental groups. 10 intact animals and 5 animals in groups on 90th and 180th day. Surgery is resection of liver left lobe and coagulation with cold plasma coagulator. The biochemical control (glucose, ALT, AST, total bilirubin, direct, alkaline phosphatase, total protein, urea, α-amylase, CRP, fibrinogen, aPTT, PTT, INR), morphological study of rat liver were performed.Results. After surgery with cold plasma hemostasis animals are active, early begin to eat. Fatal cases are not. Analysis of biochemical markers doesn't reveal statistically significant differences from the norm for the majority of indicators. Decrease of glucose concentration in the blood serum is observed in a long-term period. Histological analysis reveals an increase of the central and interlobular veins and moderate signs of edema on the 90th day. Hepatocytes with pronounced signs of protein and fatty degeneration are identified. Liver histology corresponds to the usual structure and is represented by liver lobules, separated by a small layer of connective tissue on the 180th day.Conclusion. Cold plasma coagulation in liver surgery showed effective hemostasis, minimal trauma of organ parenchyma, the lack of systemic effect and the subsequent complete regeneration of liver tissue in the treatment area.Частота повреждений печени при тупой травме живота может достигать 17,8% случаев. Послеоперационная летальность при повреждениях печени высока и составляет при колото-резаных ранах 4–10%, закрытой травме – 30,4–35,2%, сочетанной травме – до 39,3%. Для обеспечения хирургического пособия на печени необходим полный гемостаз без повреждения паренхимы органа.Цель исследования – оценить регенеративные особенности ткани печени после остановки кровотечения неравновесной плазмой в отдаленные сроки.Материал и методы. Эксперимент проводили на 20 лабораторных крысах-самцах, которые были разделены на 3 группы: 10 интактных животных (контроль) и по 5 крыс в группах на 90-е и 180-е сут после оперативного вмешательства. Выполняли атипичную резекцию левой доли печени и коагуляцию холодной плазмой. Проводили биохимический контроль (глюкоза, АЛТ, АСТ, билирубин общий, прямой, ЩФ, общий белок, мочевина, α-амилаза, СРБ), для исследования печени животных использовали морфологический метод.Результаты. После оперативного вмешательства с применением холодноплазменной коагуляции животные были активны, рано начинали питаться, летальные случаи отсутствовали. При анализе биохимических показателей крови не выявлено статистически значимых отличий от нормы для большинства показателей. На отдаленные сроки отмечалось снижение концентрации глюкозы в сыворотке крови. При гистологическом исследовании на 90-е сут наблюдались увеличение центральных и междольковых вен и умеренные признаки отека. Определялись гепатоциты с выраженными признаками белковой и жировой дистрофии. На 180-е сут гистология железы соответствовала обычному строению и была представлена печеночными дольками, разделенными небольшими прослойками соединительной ткани.Заключение. Холодноплазменная коагуляция при оперативных вмешательствах на печени показала эффективную остановку кровотечения, минимальную травму паренхимы органа, отсутствие системного эффекта и последующую полную регенерацию тканей печени в области обработки

Модель биомедицинского клеточного продукта для доклинических исследований на крупном лабораторном животном

Objective: to develop a model of a biomedical cell product that is consistent with the «homologous drug» strategy  based on protocols for preparing the cell component and scaffold carrier for preclinical studies on a large laboratory  animal (pig). Materials and methods. Biomedical cell products and skin equivalents (SE), were formed using  plasma cryoprecipitate prepared from blood plasma of healthy donors and mesenchymal stem cells (MSCs) of  human adipose tissue. Cryoprecipitate from pig blood plasma and human adipose tissue-derived MSCs were used   to form model skin equivalents (mSE). Bright-field microscopy, phase-contrast microscopy (Leica DMI 3000B)  and fluorescence microscopy (Cytation 5 imager; BioTek, USA) were used to monitor the state of cells in the  culture and in the composition of the equivalents. Scaffolds for equivalents were tested for cytotoxicity (MTT test,  direct contact method). The cell distribution density was characterized by author’s method (Patent No. 2675376  of the Russian Federation). Results. An mSE was developed for preclinical studies on a large laboratory animal  (pig). In the mSE, components that change from halogen to xenogenic conditions during transplantation to the  animal were replaced. A comprehensive approach to preparing mSE was presented. It includes sampling of primary  pig biomaterial, extraction and characterization of adipose tissue-derived MSCs, preparation of a scaffold  carrier for the corresponding «homologous drug» strategy. Cytotoxicity of the mSE scaffold was evaluated. It  was shown that mSE provides mechanical support (similar to SE) to cells, as well as comparable development of  cellular events during cultivation. Conclusion. A model of a biomedical cell product was developed. This model  is consistent with the «homologous drug» strategy for preclinical studies on a large laboratory animal (pig). The  paper presented a comprehensive approach to developing a model equivalent based on protocols for preparation  and testing of the cellular component, the scaffold carrier and the ready-to-use model equivalent.Цель: разработать модель биомедицинского клеточного продукта, согласующуюся со стратегией «гомологичный препарат» на основе протоколов подготовки клеточной составляющей и скаффолда-носителя для доклинических исследований на крупном лабораторном животном (свинье). Материалы и методы. Биомедицинские клеточные продукты – эквиваленты кожи (ЭК) формировали с использованием криопреципитата плазмы крови здоровых доноров и мезенхимальных стволовых клеток (MSCs) жировой ткани человека. Для формирования модельных эквивалентов кожи (мЭК) использовали криопреципитат плазмы крови свиней и MSCs жировой ткани свиней. Наблюдение за состоянием клеток в культуре и в составе эквивалентов проводили с использованием методов светлого поля, фазового контраста (Leica DMI 3000B) и флуоресцентной микроскопии (имиджер Cytation 5; BioTek, USA). Скаффолды эквивалентов тестировали на цитотоксичность (МТТ-тест, метод прямого контакта). Характеристику плотности распределения клеток проводили авторским способом (Пат. № 2675376 РФ). Результаты. Разработан модельный эквивалент кожи (мЭК) для проведения доклинических исследований на крупном лабораторном животном (свинье). В мЭК замещены компоненты, переходящие из алогенных условий в ксеногенные при трансплантации животному. Представлен комплексный подход для подготовки мЭК, включающий забор первичного биоматериала свиньи, выделение и характеристику MSCs жировой ткани, подготовку скаффолда-носителя, соответствующего стратегии «гомологичный препарат». Проведена оценка цитотоксичности скаффолда мЭК. Показано, что мЭК обеспечивает аналогичную эквиваленту кожи (ЭК) механическую поддержку клеток и сопоставимое развитие клеточных событий при культивировании. Вывод. Разработана модель биомедицинского клеточного продукта, согласующаяся со стратегией «гомологичный препарат» для доклинических исследований на крупном лабораторном животном (свинье). Представлен комплексный подход, для разработки модельного эквивалента основанный на протоколах подготовки и тестирования клеточной составляющей, скаффолда-носителя и готового модельного эквивалента

Морфофункциональная характеристика печени после гемостаза неравновесной плазмой на отдаленные сроки в условиях эксперимента

Research of morphofunctional properties that indicate intensity of liver injury when performing cold plasma hemostasis. The operation is an atypical resection of liver left lobe with cold plasma hemostasis. It is performed on white rats. There are a biochemical blood analysis, histological study and MRI-scanning in late period. Morphofunctional changes on the 90th and 180th day are described in the issue.Изучены морфофункциональные параметры, отражающие выраженность повреждений печени при гемостазе неравновесной плазмой. Оперативное вмешательство заключалось в атипичной резекции левой доли печени с гемостазом холодной плазмой и выполнялось на белых крысах. В отдаленные сроки проводили биохимическое исследование крови, гистологическое исследование и магнитно-резонансную томографию. В результате описаны морфофункциональные изменения на 90-е и 180-е сут

DETECTION OF CLIPPED FRAGMENTS IN ACOUSTIC SIGNALS

The paper deals with investigation of the method for detecting clipped fragments in acoustic signals with better characteristics as compared with the other known methods. This method is based on the histogram construction for the analyzed signal amplitudes and calculating the distances between the local peaks of the histogram on its tails and in the central part. The difference between histograms of non-clipped and clipped signals is that the histogram of a non-clipped signal has smoothly decaying tails while the histogram of a clipped signal has visible and easily detectable outbursts on its tails. The value of these outbursts and consequently the quality of detection of clipped fragments depends on the parameters of the method under investigation. The main aim of this paper is finding the optimal parameters of the method. Characteristics of the method are studied in detail by mathematical modeling; density functions of target values for different lengths of a studied signal frame and the number of histogram counts and levels of clipping of acoustic signals are built. It is shown that good separation between clipped and non-clipped signal fragments of acoustic signals can be achieved for the frame length between 6000 and 8000 samples and the number of histogram bins between 200 and 300. In this case the threshold level for the best separation can vary between 0.45–0.55. Examples of clipping detector operation based on the proposed method and on real acoustic signals are shown for the case of different clipping level