Phenomena of stability of the coal seam roof with a yielding support

Purpose. Determining the conditions and parameters for ensuring the stability of the coal seam roof with a yielding support in the area adjacent to face and behind it under the influence of dynamic loads based on the analytical and laboratory studies. Methods. To achieve the purpose set, analytical studies have been carried out using the basic principles of the theory of elasticity and vibrations, the hypothesis of girders and the hinged-block displacement of the stratified rock stratum. Also, the laboratory studies of models from equivalent materials have been performed, in which the coal seam roof is presented in the form of a girder having a yielding support with variable rigidity from the filling material under dynamic load. Findings. As a result of performed studies, the phenomenon has been determined that the condition for the stability of the coal seam roof is a geometric parameter that reflects moving of the girder with a yielding support, under the force impact of a falling load with a known mass and the physical-geometrical characteristics of the deformable system. It has been determined that as a result of a change in the spans length, a change in the flexural rigidity of the girder occurs, which means that the yield influence of the same supports on the stability of the coal seam roof is different. The values have been set and the relationship has been studied of the physical-mechanical characteristics of the filling mass as a yielding support. Originality. It has been proven scientifically that the stress-strain state (SSS) of a system in which the coal seam roof is studied as a girder depends on the physical-geometrical characteristics of the system, as well as the type and place of applying the external load, in case when the law of the girder movement in time is determined. Practical implications. The effective supporting of the undermined rock stratum in the working part of the longwall face and behind the face is achieved by placing the yielding supports in the mined-out space or by using the backfill in the mined-out space while conducting the stope operations, thus, increasing the efficiency of measures to protect the labour of miners in coal mines.Мета. Визначення умов і параметрів забезпечення стійкості покрівлі пласта з податливою опорою у привибійному просторі та позаду очисного вибою під впливом динамічних навантажень на основі аналітичних і лабораторних досліджень. Методика. Для досягнення поставленої мети були виконані аналітичні дослідження із застосуванням основних положень теорії пружності й коливань, гіпотези балок і шарнірно-блокового зсування породної товщі, що розшаровується, а так само лабораторні дослідження моделей з еквівалентних матеріалів, в яких покрівля вугільного пласта представлена у вигляді балки, що має податливу опору змінної жорсткості із закладного матеріалу при динамічному навантаженні. Результати. В результаті виконаних досліджень визначено феномен, що умовою стійкості покрівлі вугільного пласта, є геометричний параметр, що відображає переміщення балки з піддатливою опорою, при силовому впливі падаючого вантажу відомої маси і фізико-геометричні характеристики деформованої системи. Визначено, що в результаті зміни довжини прольотів, відбувається зміна згинальної жорсткості балки, а значить вплив податливості одних і тих же опор, на стійкість покрівлі вугільного пласта різний. Встановлено величини і досліджено взаємозв’язок фізико-механічних характеристик закладного масиву як піддатливої опори. Наукова новизна. Науково доведено, що напружено-деформований стан системи, в якій покрівля вугільного пласта досліджується як балка, залежить від фізико-геометричних характеристик системи, виду і місця докладання зовнішнього навантаження, коли визначено закон руху балки в часі. Практична значимість. Ефективне підтримання підробленої породної товщі в робочій частині лави і позаду очисного забою, досягається за рахунок розміщення у виробленому просторі піддатливих опор або застосування закладки виробленого простору при веденні очисних робіт, що так само підвищує ефективність заходів з охорони праці гірників у вугільних шахтах.Цель. Определение условий и параметров обеспечения устойчивости кровли пласта с податливой опорой в призабойном пространстве и позади очистного забоя под воздействием динамических нагрузок на основе аналитических и лабораторных исследований. Методика. Для достижения поставленной цели были выполнены аналитические исследования с применением основных положений теории упругости и колебаний, гипотезы балок и шарнирно-блокового сдвижения расслоившейся породной толщи, а также лабораторные исследования моделей из эквивалентных материалов, в которых кровля угольного пласта представлена в виде балки, имеющей податливую опору переменной жесткости из закладочного материала при динамической нагрузке. Результаты. В результате выполненных исследований определен феномен, что условием устойчивости кровли угольного пласта является геометрический параметр, отражающий перемещение балки с податливой опорой, при силовом воздействии падающего груза известной массы и физико-геометрические характеристики деформируемой системы. Определено, что в результате изменения длины пролетов, происходит изменение изгибной жесткости балки, а значит влияние податливости одних и тех же опор, на устойчивость кровли угольного пласта различно. Установлены величины и исследована взаимосвязь физико-механических характеристик закладочного массива как податливой опоры. Научная новизна. Научно доказано, что напряженно-деформированное состояние системы, в которой кровля угольного пласта исследуется как балка, зависит от физико- геометрических характеристик системы, вида и места приложения внешней нагрузки, когда определен закон движения балки во времени. Практическая значимость. Эффективное поддержание подработанной породной толщи в рабочей части лавы и позади очистного забоя, достигается за счет размещения в выработанном пространстве податливых опор или применения закладки выработанного пространства при ведении очистных работ, что так же повышает эффективность мероприятий по охране труда горнорабочих в угольных шахтах.The authors express their gratitude to the staff of the Mining Department of Donetsk National Technical University and Krasnoarmiisk (Pokrovsk) Industrial Institute for assistance in conducting the laboratory research

The peculiarities of macroscopic status of the upper gastrointestinal tract mucosa in patients with hepatic and extrahepatic portal hypertension.

Identification of endoscopic signs of concomitant pathology of the upper gastrointestinal tract allows to determine the tactics of managing patients with different forms of portal hypertension (PG). The analysis of macroscopic picture of esophagus, stomach and duodenum mucosa was carried out in 104 patients with portal hypertension (88 patients with hepatic  portal hypertension, 46 – with extrahepatic portal hypertension, 16 – without  portal hypertension). The frequency of changes in the esophagus, specific for  gastroesophageal reflux disease did  not differ significantly in the researched groups. The frequency and severity  of varicose veins of the esophagus were diagnosed more often in patients with hepatic form of portal hypertension (OR=10.0, p<0.05). The predominance of different pathological changes of the gastric mucosa in patients with extrahepatic form of portal hypertension was revealed. Portal gastropathy in this group was 5.3 times higher than in patients with hepatic hypertension and 21 times higher than in the III group (without portal hypertension) (p<0.01). There were no significant differences of endoscopic picture of the duodenum  mucosa between the researched groups

A COMPREHENSIVE STUDY OF THE STABILITY OF LATERAL ROCKS WITH A SUPPLE SUPPORT

A complex of analytical studies of the stability of lateral rocks with a supple support, where the coal seam roof was a beam model, some laboratory experiments on samples made from optical and equivalent materials, as well as some mine experiments were was carried out. As a result of the studies, it was found that the stability of lateral rocks with a supple support of crushed rock depended on the compaction of the backfill array on which the roof rocks were based. It was experimentally proved that with external force, the coefficient of compaction of the backfill array changes according to the hyperbolic dependence, the maximum values of which were determined as a result of compaction of the supple support consisting of heterogeneous fractions of the starting material of a certain bulk density. The change in the stress-strain state of the lateral rocks in the coal array with a roadway depended on the bending stiffness of the stratified rock mass and the parameters of flexible structures used to support the roadway. When supporting the roadways with supple support structures, the convergence of the lateral rocks on the contour of the stoop roadway was observed exponentially until the support was completely compressed, while supporting the roadways with coal pillars, the displacement of the rocks on the contour of the roadway increased having linear dependence due to the destruction of the pillar. The stability of the lateral rocks, which determines the operational state of the excavation roadways, was ensured by the use of supple supports or stowing the mined-out space, taking into account the reasonable granulometric content of crushed rock, which ensured the maximum values of the compaction coefficient of the backfill array when the roof and coal seat got deformed.A complex of analytical studies of the stability of lateral rocks with a supple support, where the coal seam roof was a beam model, some laboratory experiments on samples made from optical and equivalent materials, as well as some mine experiments were was carried out. As a result of the studies, it was found that the stability of lateral rocks with a supple support of crushed rock depended on the compaction of the backfill array on which the roof rocks were based. It was experimentally proved that with external force, the coefficient of compaction of the backfill array changes according to the hyperbolic dependence, the maximum values of which were determined as a result of compaction of the supple support consisting of heterogeneous fractions of the starting material of a certain bulk density. The change in the stress-strain state of the lateral rocks in the coal array with a roadway depended on the bending stiffness of the stratified rock mass and the parameters of flexible structures used to support the roadway. When supporting the roadways with supple support structures, the convergence of the lateral rocks on the contour of the stoop roadway was observed exponentially until the support was completely compressed, while supporting the roadways with coal pillars, the displacement of the rocks on the contour of the roadway increased having linear dependence due to the destruction of the pillar. The stability of the lateral rocks, which determines the operational state of the excavation roadways, was ensured by the use of supple supports or stowing the mined-out space, taking into account the reasonable granulometric content of crushed rock, which ensured the maximum values of the compaction coefficient of the backfill array when the roof and coal seat got deformed

Modern endoscopic criteria for stratifiation of patients with atrophic gastritis in the development of precancerous changes of the stomach

Purpose: to identify the most signifiant endoscopic diagnostic criteria for the development of precancerous changes of the of the stomach mucosa (SM). Material and methods. 80 patients with atrophic gastritis were examined (34 (42.5 %) men and 46 (57.5 %) women, the average age (57.7 ± 2.1) years. The diagnosis was set during endoscopic examinations and was morphologically confimed in all cases. Esophagogastroduodenoscopy was performed using EVIS EXERA III video endoscopic system with Olympus 190 gastroscope (Japan). Examination of the stomach was carried out in white light regimen, magnifiation (near focus) and NBI regimen. All examined patients were divided into groups according to the presence and prevalence of intestinal metaplasia (IM) and the presence of SM dysplasia: group I – SM atrophy without IM (10 patients), II – SM atrophy with IM, limited of the antral part (20 patients), III – SM atrophy with diffse (multifocal) IM (39 patients), IV – SM dysplasia (11 patients). Results. For the formation of group of patients with high risk of developing gastric cancer, diagnostic criteria of structural changes of gastric mucosa with pre-cancerous potential were identifid. In white light upper endoscopy, the knotted / tuberous relief of the stomach mucosa can be considered as a diagnostic criterion for sensitivity (81.4 %) and specifiity (60.0 %) indicators. The xanthomatosis of the stomach mucosa increases by 5 times the risk of IM or dysplasia in patients with atrophic gastritis (sensitivity – 47.1 %, specifiity – 90.0 %). Magnifiation endoscopy and endoscopy with narrow-band imaging allowed us to establish another diagnostic criterion for the formation of the group with high risk of developing gastric cancer: pyloric metaplasia (pseudopylorisation) of the gastric corpus. Pyloric metaplasia increases the frequency of detection of structural precancerous changes in a patient with atrophic gastritis by almost 7 times (sensitivity – 71.4 %, specifiity – 70.0 %). Conclusion. The established endoscopic criteria (nodular relief of the stomach (OR = 4.96), xanthomatosis of the stomach (OR = 4.94), pyloric metaplasia of the stomach body (OR = 6.72)) can be applied in the formation of a group of patients with atrophic gastritis who have high potential for the development of gastric cancer and require careful examination using modern endoscopic equipment and dynamic surveillance

UROGENITAL TRACT MICROFLORA IN SEXUAL PARTNERS WITH CHRONIC GENITOURINARY TRICHOMONIASIS

Trichomonas infection is a scientific and clinical problem in dermatology, urology, obstetrics and gynecology. This infection in men and women is often causes to urethritis, cystitis, prostatitis, post-abortion infection, premature labor and other diseases. This literature review has shown that in spite of a lot of numbers of scientific data concerning the impact of trichomoniasis to urogenital bioceonosis of both men and women, there is no enough data about influence of trichomoniasis to urinary microecology in sexual partners. Meanwhile, this question is in the field of scientific and applied interest and need to be studied

DIAGNOSTIC CHARACTERISTICS OF A LATEX ANTIGEN HELICOBACTER TEST-SYSTEM

Purpose: The study of operation diagnostic characteristics of a newly constructed helicobacter test-system which is designed to determine the total antibodies in the blood serum in volumetric agglomeration reaction.Materials and methods: Blood sera of 224 gastroenterological patients were studied with the help of diagnostic system constructed. Commercial immune-enzyme blood assay systems were used to be the referent method.Results: Diagnostic operation characteristics of a latex antigen helicobacter test-system were determined with the help of referent serological diagnostic methods. At the cut-off point 1:160 the sensitivity, specificity and diagnostic effectiveness are 94,9%, 79,3% и 88,2%, respectively.Summary: The cut-off point 1:160 is shown to be used as a diagnostic threshold

СРАВНИТЕЛЬНЫЕ ХАРАКТЕРИСТИКИ ИЗВЕСТНЫХ МУКОЛИТИКОВ В БАЗИСНОЙ ТЕРАПИИ МУКОВИСЦИДОЗА У ДЕТЕЙ

The primary objective in the mucoviscidosis therapy is to ensure normal rheology of respiratory secretion for effective evacuationthereof from the bronchial tree and nasal sinuses. Enzyme drug dornase alfa features the best evidence base for effectiveness and safety of use to treat mucoviscidosis among mucolytics; it rapidly transforms thick viscous sputum into liquid secretion. Along with that, numerous studies have confirmed anti-inflammatory and antibacterial effects thereof: the enzyme breaks down biofilm of the mucoid Pseudomonas aeruginosa, thus reducing volume of the destructive component in pulmonary tissue in the event of an inflammation; it is capable of decreasing concentration of neutrophil elastase and interleukin 8 in sputum, as well as of matrix metal proteinases in bronchoalveolar lavage. Continuous intake of this drug in combination with kinesitherapy and other baseline drugs ensures the patient’s well-being, lower rate of bronchopulmonary process exacerbations, reduction in the hospital admission rate and significant improvement of the quality of life. При терапии муковисцидоза главной задачей является обеспечение нормальной реологии секрета дыхательных путей для эффективной его эвакуации из бронхиального дерева и пазух носа. Среди муколитических средств наилучшей доказательной базой эффективности и безопасности при муковисцидозе обладает ферментный препарат дорназа альфа, которая быстро превращает густую вязкую мокроту в жидкий секрет. Кроме того, в многочисленных исследованиях доказаны противовоспалительный и антибактериальный эффекты: фермент разрушает биофильм мукоидной синегнойной палочки, тем самым уменьшая деструктивный компонент в легочной ткани при воспалении; способен снижать концентрацию нейтрофильной эластазы и интерлейкина  8 в мокроте, а также матричных металлопротеиназ в бронхоальвеолярном лаваже. Постоянный прием препарата в сочетании с кинезитерапией и другими базисными лекарственными средствами обеспечивает больному хорошее самочувствие, урежение обострений бронхолегочного процесса, уменьшение числа госпитализаций и значительное повышение качества жизни.

Ion-Pair Chromatography for the Determination of Capreomycin Sulfate Components and Related Substances

Chromatographic methods for the analysis of antibiotic degradation products are widely used to evaluate the quality of medicines. Natural multicomponent antibiotics, such as capreomycin, are the most challenging compounds in terms of developing analytical procedures for related substances. Capreomycin sulfate monographs of the leading pharmacopoeias do not contain specifications for related substances. The key requirement concerns the sum of the main components of capreomycin calculated by normalising the peak areas in the test solution chromatogram. Therefore, it is important to develop an analytical procedure for determining not only the main components but also related substances of capreomycin.The aim of the study was to develop an analytical procedure for determining both the main components (IA, IB, IIA, and IIB) and related substances of capreomycin by ion-pair ultra-high-performance liquid chromatography (UHPLC).Materials and methods. This study examined capreomycin sulfate powder, an active pharmaceutical ingredient (API). Capreomycin sulfate solutions were analysed after artificial degradation (alkaline or acid hydrolysis) to demonstrate the resolution, selectivity, and efficiency of the experimental chromatographic system. The authors used an Agilent 1100 liquid chromatography instrument (Agilent Technologies) and chromatographic columns: Kinetex C18, YMC-Triart С18, ACQUITY UPLC BEH C18, ACQUITY UPLC BEH C8, ACQUITY UPLC BEH Phenyl, and ACQUITY UPLC CSH C18 (experimental procedure) or Acclaim C18, Zorbax SB-C18, and XBridge BEH130 C18 (The International Pharmacopoeia procedure).Results. In contrast to pharmacopoeial procedures, which evaluate only the component composition, the experimental procedure under the selected chromatography conditions can determine both the component composition and related substances of capreomycin. This advantage results from substituting a column packed with 1.7 µm particles for a 5 µm column required for pharmacopoeial procedures. The experimental procedure remains suitable for liquid chromatography instruments with a pressure limit of no more than 400 bar in the gradient elution mode with two mobile phases. According to the efficiency and selectivity evaluation, ACQUITY UPLC BEH C18 columns (150 × 2.1 mm, 1.7 μm) provide optimal peak resolution for capreomycin isoforms and related substances after artificial degradation of capreomycin.Conclusions. This experimental procedure based on ion-pair UHPLC may be used in the production and stability testing of capreomycin medicines to evaluate the API quality by the content of its main components and related substances

Clinical case of facial granuloma after filler injection

The article contains up-to-date information about injectable facial fillers and fillers-related complications. Various sources were analyzed, data on the epidemiology, clinical features and diagnosis of filler-related foreign body granulomas (FBG) are presented. Histopathology of FBG is described. Rare clinical case of foreign body granuloma that occurred after skin injections of stabilized hyaluronic acid filler is demonstrated. Modern patient management’s approaches are describedПредставлена актуальная информация о применении филлеров в косметологии, возможных осложнениях после их введения. Рассмотрены данные эпидемиологии, клинической и патоморфологической картины, диагностики гранулем инородного тела, возникающих после введения гелевых имплантов в кожу. В статье продемонстрирован редкий клинический случай гранулемы, развившейся после инъекций в кожу и мягкие ткани лица препарата стабилизированной гиалуроновой кислоты. Описаны современные подходы к ведению пациентов с данным осложнение

Особенности отравлений бензодиазепинами у лиц пожилого и старческого возраста

AIM OF THE STUDY To study benzodiazepine poisoning in geriatric patients compared to patients of working age.MATERIAL AND METHODS We examined 82 patients with benzodiazepine poisoning, hospitalized in the Department of Acute Poisoning and Somatopsychiatric Disorders of the N.V. Sklifosovsky Research Institute for Emergency Medicine in 2020–2021, which were divided into age categories: young (18–44 years old), middle (45–59 years old) and older (over 60 years old) age. The presence of benzodiazepines in urine was confirmed by immunochromatographic analysis and gas chromatography–mass spectrometry (GC-MS). The concentration of phenazepam in the blood and urine was determined in 45 patients by GC-MS. Statistical processing of the material was performed using the IBM program SPSS Statistics 27.0. The median (Me), 25th and 75th percentiles were determined. The comparison of quantitative data was performed using non-parametric criteria, the level of significance was taken as p<0.05.RESULTS It was found that acute phenazepam poisoning prevailed in all age groups (90% of patients). Among young and middle-aged patients, moderate and deep stunning (GCS score 12–14) prevailed, and in older people moderate and severe poisoning prevailed (GCS score 3–12), with no statistically significant differences in blood concentrations of phenazepam between the groups. In patients of the older age group with benzodiazepine poisoning, compared to people of working age, the development of respiratory failure was statistically significantly more frequent — 13.8-fold, pneumonia — 12.6-fold, vein thrombosis of the lower extremities — 7.8-fold, trophic skin changes — 29-fold. The duration of treatment in older patients with benzodiazepine poisoning was 3.5-fold higher than in young and middle-aged patients, mortality in the older age group was 41%.CONCLUSION The course of acute poisoning with benzodiazepines, including phenazepam, in the elderly and senile age differs in comparison with persons of working age with a high incidence of complications and adverse outcomes.ЦЕЛЬ ИССЛЕДОВАНИЯ Изучить особенности отравлений бензодиазепинами у гериатрических пациентов по сравнению с лицами трудоспособного возраста.МАТЕРИАЛ И МЕТОДЫ Обследованы 182 пациента с отравлением бензодиазепинами, госпитализированных в отделение острых отравлений и соматопсихиатрических расстройств НИИ СП им. Н.В. Склифосовского в период 2020–2021 гг., которые были разделены на возрастные категории — молодого (18– 44 года), среднего (45–59 лет) и старшего (старше 60 лет) возраста. Наличие бензодиазепинов в моче подтверждали методами иммунохроматографического анализа и газовой хроматографии– масс-спектрометрии (ГХ-МС). Концентрацию феназепама в крови и моче определяли у 45 пациентов методом ГХ-МС. Статистическая обработка материала выполнена с помощью программы IBM SPSS Statistics 27.0. Для данных определяли медиану (Mе), 25-й и 75-й процентили. Сравнение количественных данных проводили с использованием непараметрических критериев, за уровень значимости был принят р<0,05.РЕЗУЛЬТАТЫ Установлено, что во всех возрастных группах превалировали острые отравления феназепамом (90% пациентов). Среди лиц молодого и среднего возраста преобладали больные в умеренном и глубоком оглушении (12–14 баллов по шкале комы Глазго — ШКГ), а в старшем возрасте — отравление средней и тяжелой степени (3–12 баллов по ШКГ), при этом статистически значимых различий концентраций феназепама в крови между группами не обнаружено. У пациентов старшей возрастной группы с отравлением бензодиазепинами по сравнению с лицами трудоспособного возраста статистически значимо чаще регистрировали развитие дыхательной недостаточности — в 13,8 раза, пневмонии — в 12,6 раза, тромбоза вен нижних конечностей — в 7,8 раза, трофических изменений кожных покровов — в 29 раз. Продолжительность лечения у пациентов старшего возраста с отравлением бензодиазепинами была выше в 3,5 раза по сравнению с лицами молодого и среднего возраста, летальность в старшей возрастной группе составила 41%.ЗАКЛЮЧЕНИЕ Течение острых отравлений бензодиазепинами, в том числе феназепамом, в пожилом и старческом возрасте отличается при сравнении с показателями у лиц трудоспособного возраста значительно более высокой частотой развития осложнений и, как правило, наличием неблагоприятных исходов