The experimental model of laboratory animals’ intoxication by polyacrylonitrile pyrolysis products

Purpose of research – To develop an experimental model of intoxication of laboratory animals by polyacrylonitrile pyrolysis products. Materials and methods. The study was performed on the rats. Pyrolysis of polyacrylonitrile fibers was carried out at temperature of 270–350 °C. The laboratory animals were exposed to static inhalation intoxication by pyrolysis products for 15 min. Vital signs were determined in animals before and 5 minutes after intoxication. Arterial blood oxygenation index and acid-base state parameters were evaluated at 10 min after exposure. Qualitative detection of cyanides in brain and myocardial samples obtained 15 minutes after intoxication was carried out by gas chromatography. Results and discussion. It was found that the weight of the material (containing 85 % polyacrylonitrile), which pyrolysis products lead to the death of 50 % of laboratory animals within 24 hours after exposure, was 0.81 ± 0.15 g. The animals showed signs of poisoning by substances interrupting the processes of cell bioenergy when exposed to pyrolysis products obtained under specified conditions. The evident bradycardia and bradypnea (p < 0,05), and significant decrease in rectal temperature was marked. The exposed animals did not differ (p > 0,05) from the rats of the control group by the parameters of oxygenation. The signs of decompensated metabolic acidosis were detected in blood. The cyanide peak was detected by gas chromatography with a retention time of 3.78 min in brain and heart muscle biopsies. The experimental model, in which inhalation exposure of pyrolysis products of polyacrylonitrile fibers led to severe intoxication of laboratory animals, was developed. The model can be used to search for means of etiotropic and pathogenetic therapy of poisoning by combustion products of nitrogen-containing polymeric materials

Anisotropy of reflection spectrum and band structure of SbSI

Access full text - https://doi.org/10.1007/BF00820060Anisotropy of the SbSI reflection spectra at various temperatures (300, 273, and 90 °K) is studied. Selection rules are examined for matrix transition elements at extreme points for crystals with symmetry D2h16, C2v9, and C22corresponding to different states of SbSI during phase transitions. A comparison of experimental data with theoretical and group-theoretical analysis results made possible a conclusion on the character of the band spectrum

Биомаркеры острого респираторного дистресс-синдрома: проблемы и перспективы их применения

The review analyzes the results of modern clinical and experimental studies on the search and informative value of biomarkers for acute respiratory distress syndrome (ARDS). It describes ARDS biomarkers of the main morphological changes in the lungs and severity of the systemic inflammatory response syndrome. Biomarkers of injury of bronchial epithelium, alveolar epithelium, vascular endothelium and pulmonary extracellular matrix were analyzed to determine the most informative indicators of ARDS of different etiology. It was found that for diagnosis and prognosis of the course of ARDS, the following biomarkers were the most informative: interleukin-6, a soluble form of the receptor for advanced glycation end products (sRAGE), surfactant protein D, protein KL-6, vascular endothelial growth factor, and angiopoietin-2. Using a multimarker panel for simultaneous determination of these indicators can promote rapid diagnostics of ARDS.В обзоре проведен анализ результатов современных клинических и экспериментальных исследований, посвященных поиску и оценке информативности биомаркеров острого респираторного дистресс-синдрома (ОРДС). Приведены сведения о биомаркерах ОРДС, характеризующих основные морфологические изменения легких и степень выраженности синдрома системного воспалительного ответа. С целью определения наиболее информативных показателей ОРДС различной этиологии проанализированы данные о биомаркерах, свидетельствующих о повреждении бронхиального эпителия, альвеолярного эпителия, эндотелия сосудов и экстрацеллюлярного матрикса легких. Установлено, что для диагностики и прогноза течения ОРДС наибольшим потенциалом обладают: интерлейкин-6, растворимая форма рецептора конечных продуктов гликозилирования (sRAGE), сурфактантный белок D, белок KL-6, фактор роста эндотелия сосудов, ангиопоэтин-2. Для экспресс-диагностики ОРДС следует считать перспективным одновременное определение перечисленных показателей, которое может быть реализовано в виде мультимаркерной панели

Кількісний аналіз джерел іонізуючого випромінювання камер поділу

Проведено аналіз радіаційної небезпеки джерел іонізуючого випромінювання, застосовуваних у камерах поділу типу КНТ31 і КНТ31-1, де матеріалом радіатора є уран, збагачений до 90 % ізотопом 235U, з вмістом близько 1 % домішок 234U. Розраховано сумарну й питому активність, а також потужність еквівалентної дози на відстані 0,1 м від поверхні джерел іонізуючого випромінювання.</jats:p