39 research outputs found
ANALYSIS OF THE RESULTS OF SURGICAL PROCEDURES ADVISABLE FOR CHRONIC PANCREATITIS WITH THE PREDOMINANT LESION OF THE PANCREATIC HEAD
Recently, studies comparing various variants of operations to establish the optimal method of surgical treatment for chronic pancreatitis with pancreatic head lesions from the point of view of evidence-based medicine have been carried out in the world. However, these comparative studies do not take into account differences in the clinical and morphological forms of the disease, in particular, chronic pancreatitis with a predominant and isolated lesion of the head. Subtotal resection of the pancreatic head with proximal pancreatojejunostomy, suitable for an isolated lesion of the head, does not solve all the problems of chronic pancreatitis with a predominant lesion of the head. In this case, the violation of the outflow of pancreatic juice along the pathologically changed main pancreatic duct from the left half of the gland is not eliminated. It is impossible to unambiguously support the hypothesis of the feasibility of performing subtotal resection of the pancreatic head with proximal pancreatojejunostomy in chronic pancreatitis with a predominant lesion of the head with a uniformly expanded main pancreatic duct. With this form of chronic pancreatitis, cicatricial strictures can form in the main pancreatic duct, which can lead to ductal hypertension and serve as an indication for reoperation. The feasibility of using Beger operation in chronic pancreatitis with a predominant lesion of the head is doubtful, since the intersection of the isthmus and the need for a T-shaped longitudinal pancreatojejunostomy makes this intervention technically difficult and unsafe. Based on the studies performed, it is impossible to say with certainty about the reliable advantages of one type of operations over another. To obtain reliable results, it’s necessary to conduct evidence-based studies comparing subtotal resection of the pancreatic head with longitudinal pancreatojejunostomy with other types of interventions only for chronic pancreatitis with a predominant head lesion, excluding from the study patients with chronic pancreatitis with isolated head lesion
Conjugation of Organoruthenium(II) 3-(1H-Benzimidazol-2-yl)pyrazolo[3,4-b]pyridines and Indolo[3,2-d]benzazepines to Recombinant Human Serum Albumin: a Strategy To Enhance Cytotoxicity in Cancer Cells
Five organoruthenium complexes [RuCl(η6-arene)(L)]Cl with a modified arene ligand, namely, 4-formylphenoxyacetyl-η6-benzylamide, and L = 3-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines or indolo[3,2-d]benzazepines were synthesized and conjugated to recombinant human serum albumin in order to improve their drug targeting and delivery to cancer cells, and a marked increase in cytotoxicity was observed
Исследование локальной гидродинамики теплоносителя в смешанной активной зоне реактора ВВЭР
The article presents the results of experimental studies of the local hydrodynamics of the coolant flow in the mixed core of the VVER reactor, consisting of the TVSA-T and TVSA-T mod.2 fuel assemblies. Modeling of the flow of the coolant flow in the fuel rod bundle was carried out on an aerodynamic test stand. The research was carried out on a model of a fragment of a mixed core of a VVER reactor consisting of one TVSA-T segment and two segments of the TVSA-T.mod2. The flow pressure fields were measured with a five-channel pneumometric probe. The flow pressure field was converted to the direction and value of the coolant velocity vector according to the dependencies obtained during calibration. To obtain a detailed data of the flow, a characteristic cross-section area of the model was selected, including the space cross flow between fuel assemblies and four rows of fuel rods of each of the TVSA fuel assemblies. In the framework of this study the analysis of the spatial distribution of the projections of the velocity of the coolant flow was fulfilled that has made it possible to pinpoint regularities that are intrinsic to the coolant flowing around spacing, mixing and combined spacing grates of the TVSA. Also, the values of the transverse flow of the coolant caused by the flow along hydraulically nonidentical grates were determined and their localization in the longitudinal and cross sections of the experimental model was revealed. Besides, the effect of accumulation of hydrodynamic flow disturbances in the longitudinal and cross sections of the model caused by the staggered arrangement of hydraulically non-identical grates was determined. The results of the study of the coolant cross flow between fuel assemblies interaction, i.e. between the adjacent TVSA-T and TVSA-T mod.2 fuel assemblies were adopted for practical use in the JSC of “Afrikantov OKB Mechanical Engineering” for assessing the heat engineering reliability of VVER reactor cores; also, they were included in the database for verification of computational hydrodynamics programs (CFD codes) and for detailed cell-based calculation of the reactor core.В статье представлены результаты экспериментальных исследований локальной гидродинамики потока теплоносителя в смешанной активной зоне реактора ВВЭР, состоящей из ТВСА-Т и ТВСА-Т.mod.2. Моделирование процессов течения потока теплоносителя в пучке твэлов проводилось на аэродинамическом стенде. Исследования осуществлялись на модели фрагмента смешанной активной зоны реактора ВВЭР, состоящей из одного сегмента ТВСА-Т и двух ТВСА-Т.mod.2. Поля давлений потока измеряли пятиканальным пневмометрическим зондом. Поле давлений потока согласно зависимостям, полученным при тарировке, пересчитывалось в направление и величину вектора скорости теплоносителя. Для создания детальной картины течения потока была выделена характерная область поперечного сечения модели, включающая межкассетное пространство и четыре ряда твэлов каждой из топливных сборок ТВСА. В рамках реализации данного исследования проведен анализ пространственного распределения проекций скорости потока теплоносителя, который позволил выявить закономерности обтекания теплоносителем дистанционирующих, перемешивающих и комбинированных дистанционирующих решеток ТВСА, определены величины поперечных потоков теплоносителя, вызванных обтеканием гидравлически неидентичных решеток, установлена их локализация в продольном и поперечном сечениях экспериментальной модели. Кроме того, выявлен эффект накопления гидродинамических возмущений потока в продольном и поперечном сечениях модели, вызванный шахматным расположением гидравлически неидентичных решеток. Результаты исследования межкассетного взаимодействия теплоносителя между соседними ТВСА-Т и ТВСА-Т.mod.2 приняты для практического использования в АО «ОКБМ Африкантов» при оценке теплотехнической надежности активных зон реакторов ВВЭР и включены в базу данных для верификации программ вычислительной гидродинамики (CFD-кодов) и детального поячеечного расчета активной зоны реакторов
Virus-induced permeability transition in mitochondria
AbstractIsolated rat liver mitochondria undergo permeability transition after supplementation with a suspension of tobacco mosaic virus. Four mitochondrial parameters proved the opening of the permeability transition pore in the inner mitochondrial membrane: increased oxygen consumption, collapse of the membrane potential, release of calcium ions from mitochondria, and high amplitude mitochondrial swelling. All virus-induced changes in mitochondria were prevented by cyclosporin A. These effects were not observed if the virus was treated with EGTA or disrupted by heating. Protein component of the virus particle in the form of 20S aggregate A-protein, or helical polymer, as well as supernatant of the heat-disrupted virus sample, had no effect on mitochondrial functioning. Electron microscopy revealed the direct interaction of the virus particles with isolated mitochondria. The possible role of the mitochondrial permeability transition pore in virus-induced apoptosis is discussed
Investigation of Coolant Local Hydrodynamics in the Mixed Core of the VVER Reactor
The article presents the results of experimental studies of the local hydrodynamics of the coolant flow in the mixed core of the VVER reactor, consisting of the TVSA-T and TVSA-T mod.2 fuel assemblies. Modeling of the flow of the coolant flow in the fuel rod bundle was carried out on an aerodynamic test stand. The research was carried out on a model of a fragment of a mixed core of a VVER reactor consisting of one TVSA-T segment and two segments of the TVSA-T.mod2. The flow pressure fields were measured with a five-channel pneumometric probe. The flow pressure field was converted to the direction and value of the coolant velocity vector according to the dependencies obtained during calibration. To obtain a detailed data of the flow, a characteristic cross-section area of the model was selected, including the space cross flow between fuel assemblies and four rows of fuel rods of each of the TVSA fuel assemblies. In the framework of this study the analysis of the spatial distribution of the projections of the velocity of the coolant flow was fulfilled that has made it possible to pinpoint regularities that are intrinsic to the coolant flowing around spacing, mixing and combined spacing grates of the TVSA. Also, the values of the transverse flow of the coolant caused by the flow along hydraulically nonidentical grates were determined and their localization in the longitudinal and cross sections of the experimental model was revealed. Besides, the effect of accumulation of hydrodynamic flow disturbances in the longitudinal and cross sections of the model caused by the staggered arrangement of hydraulically non-identical grates was determined. The results of the study of the coolant cross flow between fuel assemblies interaction, i.e. between the adjacent TVSA-T and TVSA-T mod.2 fuel assemblies were adopted for practical use in the JSC of “Afrikantov OKB Mechanical Engineering” for assessing the heat engineering reliability of VVER reactor cores; also, they were included in the database for verification of computational hydrodynamics programs (CFD codes) and for detailed cell-based calculation of the reactor core