219 research outputs found

    Oil-generating potential of bituminous rocks from Permian and Domanic deposits in Tatarstan by the data of the pyrolytic Rock-Eval method

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    Using the Rock-Eval pyrolytic method, a comparative analysis of bituminous rock samples from the Permian deposits of the Ashalchinskoye oil deposit and the house (Domanic) deposits of the Romashkinskoye oil field was carried out and their oil-generating potential was estimated. It is shown that according to the content of organic matter, rocks differentiate from very good productive deposits to satisfactory. Permian rocks contain a high content of free hydrocarbons, after extraction, which the oil-producing potential of rocks sharply decreases. The residual organic matter is characterized by low values of the hydrogen index, high values of the oxygen index and a low degree of maturity, which is typical for kerogen of type III, formed from the sediments of the continental type. A distinctive feature of the dominant rocks is the low content of free hydrocarbons and the high content of insoluble kerogen of types I and II associated with organic matter of marine origin and possessing high oil and gas generation potential, the realization of which with the formation of free hydrocarbons is possible using technologies simulating artificial maturation of kerogen directly in productive layers. The heterogeneity of rocks from the Permian and Domanic deposits by the oil-generating potential determined by the different organic matter contents in rocks, by its nature and resistance to thermal effects, indicates the various possibilities and conditions for its implementation

    The Interaction of Plasma Sialylated and Desialylated Lipoproteins with Collagen from the Intima and Media of Uninvolved and Atherosclerotic Human Aorta

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    We have evaluated the binding of sialylated and desialylated lipoproteins to collagen isolated from the proteoglycan and musculoelastic layers of intima and media of uninvolved human aorta and atherosclerotic lesions. Comparing various collagen preparations from the uninvolved intima-media, the binding of sialylated apoB-containing lipoproteins was best to collagen from the intimal PG-rich layer. Binding of sialylated apoB-containing lipoproteins to collagen from this layer of fatty streak and fibroatheroma was 1.4- and 3.1-fold lower, respectively, in comparison with normal intima. Desialylated VLDL versus sialylated one exhibited a greater binding (1.4- to 3.0-fold) to all the collagen preparations examined. Desialylated IDL and LDL showed a higher binding than sialylated ones when collagen from the intimal layers of fibroatheroma was used. Binding of desialylated HDL to collagen from the intimal PG-rich layer of normal tissue, initial lesion, and fatty streak was 1.2- to 2.0-fold higher compared with sialylated HDL

    A complex model of a drilling rig rotor with adjustable electric drive

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    A modified mathematical model of an asynchronous electric drive of the rotor – a drill string – a bit – a rock is considered and implemented, which develops and generalizes the results of previously performed studies. The model includes the following subsystems: a model of an asynchronous drive with vector control; a model of formation of the resistance moment at the bottom of the bit, taking into account the peculiarities of the interaction between the bit and the rock; a model of a multi-mass mechanical part that takes into account the deformation of the drill string; subsystem for the  drilling rig energy-technological parameters formation. The integrated model makes it possible to calculate and evaluate the selected drilling modes, taking into account their electro-mechanical, energy and technological efficiency and the dynamics of drilling processes. The performed computer simulation of drilling modes confirmed the possibility of a stick-slip effect accompanied by high-frequency vibrations during bit stops, which may change the direction of rotation of the bit, its accelerated wear and unscrewing of the drilling tool. Long bit stops lead to a significant decrease in the average bit rotation speed, which can explain the decrease in the ROP and increase in energy consumption when drilling in the zone of unstable bit rotation. The model can be used as a base for further improvement of rotary drilling control systems

    Transformations of hydrocarbons of Ashal’hinskoe heavy oil under catalytic aquathermolysis conditions

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    © 2017, Pleiades Publishing, Ltd. The influence of temperatures of 250, 300, and 350°C on the character of changes in the group and hydrocarbon compositions of heavy oil from the Ashal’chinskoe field in laboratory experiments on the simulation of oil aquathermolysis processes under reservoir conditions has been revealed. The experiments have been carried out in the presence of kaolin as a rock-forming mineral, using oil-soluble iron carboxylate and tetralin as a proton donor. It has been shown that temperature elevation to 300 and 350°C increases the amount of saturated fractions by factors of 1.5 and 1.75, respectively, and decreases the resin content almost by half in comparison with the initial oil. The proportion of n-alkanes and light alkylcyclohexane and trimethylalkylbenzene homologues in the saturated fractions increases as a result of cracking reactions involving the preferential degradation of high-molecular-weight resins. A noticeable increase in the amount of newly formed hydrocarbons and asphaltenes at the temperature of 350°C indicates that not only intensive cracking processes, but also condensation processes occur under these conditions. Changes in the quantitative and qualitative composition of the proton donor tetralin by its dehydrogenation to form naphthalene and hydrogenation to yield the cis- and trans-isomers of decalin have been revealed

    Geoantineutrino Spectrum, 3He/4He-ratio Distribution in the Earth's Interior and Slow Nuclear Burning on the Boundary of the Liquid and Solid Phases of the Earth's Core

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    The description problem of geoantineutrino spectrum and reactor antineutrino experimental spectrum in KamLAND, which takes place for antineutrino energy \~2.8 MeV, and also the experimental results of the interaction of uranium dioxide and carbide with iron-nickel and silicaalumina melts at high pressure (5-10 GP?) and temperature (1600-2200C) have motivated us to consider the possible consequences of the assumption made by V.Anisichkin and coauthors that there is an actinid shell on boundary of liquid and solid phases of the Earth's core. We have shown that the activation of a natural nuclear reactor operating as the solitary waves of nuclear burning in 238U- and/or 232Th-medium (in particular, the neutron- fission progressive wave of Feoktistov and/or Teller-Ishikawa-Wood) can be such a physical consequence. The simplified model of the kinetics of accumulation and burnup in U-Pu fuel cycle of Feoktistov is developed. The results of the numerical simulation of neutron-fission wave in two-phase UO2/Fe medium on a surface of the Earth's solid core are presented. The georeactor model of 3He origin and the 3He/4He-ratio distribution in the Earth's interior is offered. It is shown that the 3He/4He ratio distribution can be the natural quantitative criterion of georeactor thermal power. On the basis of O'Nions-Evensen-Hamilton geochemical model of mantle differentiation and the crust growth supplied by actinid shell on the boundary of liquid and solid phases of the Earth's core as a nuclear energy source (georeactor with power of 30 TW), the tentative estimation of geoantineutrino intensity and geoantineutrino spectrum on the Earth surface are given.Comment: 28 pages, 12 figures. Added text, formulas, figures and references. Corrected equations. Changed content of some section

    NON-STATIONARY PHOTOCONDUCTIVITY OF GaN NANOCOMPOSITES IN ARTIFICIAL OPAL MATRIX

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    Abstract It was recently proposed to use synthetic opals as a host matrix for obtaining 3D arrays of electronic nanodevice

    Micro-Raman Mapping of 3C-SiC Thin Films Grown by Solid–Gas Phase Epitaxy on Si (111)

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    A series of 3C-SiC films have been grown by a novel method of solid–gas phase epitaxy and studied by Raman scattering and scanning electron microscopy (SEM). It is shown that during the epitaxial growth in an atmosphere of CO, 3C-SiC films of high crystalline quality, with a thickness of 20 nm up to few hundreds nanometers can be formed on a (111) Si wafer, with a simultaneous growth of voids in the silicon substrate under the SiC film. The presence of these voids has been confirmed by SEM and micro-Raman line-mapping experiments. A significant enhancement of the Raman signal was observed in SiC films grown above the voids, and the mechanisms responsible for this enhancement are discussed

    Alterations in Adenosine Metabolism and Signaling in Patients with Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis

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    Background: Adenosine is generated in response to cellular stress and damage and is elevated in the lungs of patients with chronic lung disease. Adenosine signaling through its cell surface receptors serves as an amplifier of chronic lung disorders, suggesting adenosine-based therapeutics may be beneficial in the treatment of lung diseases such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Previous studies in mouse models of chronic lung disease demonstrate that the key components of adenosine metabolism and signaling are altered. Changes include an upregulation of CD73, the major enzyme of adenosine production and down-regulation of adenosine deaminase (ADA), the major enzyme for adenosine metabolism. In addition, adenosine receptors are elevated. Methodology/Principal Findings: The focus of this study was to utilize tissues from patients with COPD or IPF to examine whether changes in purinergic metabolism and signaling occur in human disease. Results demonstrate that the levels of CD73 and A2BR are elevated in surgical lung biopsies from severe COPD and IPF patients. Immunolocalization assays revealed abundant expression of CD73 and the A2BR in alternatively activated macrophages in both COPD and IPF samples. In addition, mediators that are regulated by the A 2BR, such as IL-6, IL-8 and osteopontin were elevated in these samples and activation of the A 2BR on cells isolated from the airways of COPD and IPF patients was shown to directly induce the production of these mediators. Conclusions/Significance: These findings suggest that components of adenosine metabolism and signaling are altered in

    Первичные результаты D3-лимфодиссекции при хирургическом лечении рака правой ободочной кишки

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    Introduction. Despite recent significant progress in chemotherapy treatment of primary non-metastatic cancer of the right half of the segmented intestine, surgery remains the primary method of treatment. Radical surgery includes removal of the tumour within the healthy tissues and regional lymph glands. Considering localisation of the primary tumour in the right half of the segmented intestine, hemicolectomy is typically performed on the right side. W. Hohenberger et al. have formulated a new concept of radical surgical treatment of the segmented intestine, consisting of the following components: complete mesocolic excision, early ligation of the lymphovascular pedicle and lymph dissection in the D3 volume.Purpose of the research: to analyse the early results of surgical treatment of cancer in the right half of the segmented intestine in the volume of the right-side hemicolectomy with D3 lymph node dissection depending on the method of surgical treatment.Materials and methods. At the premises of the Surgical Department No. 3 of the Republican Oncologic Dispensary (city of Ufa) a retrospective analysis of data of 59 patients was performed following right-side hemicolectomy using complete mesocolic excision, ligation lymphovascular pedicles and lymph node dissection in the D3 volume. Depending on the surgical access, all patients were divided into two main groups: group I (48 patients) — surgeries were performed using open method; group II (11 patients) — using laparoscopy.Results and discussion. Table 2 shows that the surgery performed with laparoscopy takes longer. However, statistically it results in significantly less blood loss. Patients who underwent open surgery were characterised by a longer stay in hospital. One of the effectiveness criteria is the number of removed lymph glands not differing for either group.Conclusion. Extended lymph dissection in the D3 volume for segmented intestine on the right side during cancer is a possible and safe method in case of laparoscopic and open procedures.Введение. Несмотря на значительный прогресс химиотерапии в последние годы, в лечении первичного неметастатического рака правой половины ободочной кишки хирургический метод является основным методом лечения. Радикальное хирургическое вмешательство включает в себя удаление опухоли в пределах здоровых тканей и регионарных лимфатических узлов. В условиях локализации первичной опухоли в правой половине ободочной кишки традиционно выполняется гемиколэктомия справа. W. Hohenberger и др. сформулировали новую концепцию радикального оперативного лечения ободочной кишки, состоящую из следующих компонентов: полная мезоколонэктомия, раннее лигирование лимфоваскулярной ножки и лимфодиссекция в объеме D3.Цель исследования: провести анализ ранних результатов хирургического лечения рака правой половины ободочной кишки в объеме правосторонней гемиколэктомии с D3-лимфодиссекцией в зависимости от метода оперативного лечения.Материалы и методы. На базе хирургического отделения № 3 Республиканского онкологического диспансера (г.  Уфа) проведен ретроспективный анализ данных 59 пациентов после правосторонней гемиколэктомии по технике complete mesocolic excision лигированием лимфоваскулярной ножки и лимфодиссекцией в объеме D3. В зависимости от оперативного доступа все пациенты были разделены на две основные группы: I группа (48 пациентов) — оперативное вмешательство проводилось открытым способом и II группа (11 пациентов) — лапароскопическим способом.Результаты и обсуждение. Из данных таблицы 2 видно, что хирургическое вмешательство, выполненное лапароскопически, оказывается более продолжительным. Однако статистически значимо сопровождалось меньшей кровопотерей. Пациенты, подвергшиеся открытой операции, характеризовались более длительным пребыванием в стационаре. Один из критериев эффективности — количество удаленных лимфоузлов — не различался для обеих групп.Заключение. Расширенная лимфодиссекция в объеме D3 при раке ободочной кишки справа является возможным и безопасным методом в случае выполнения как лапароскопических, так и открытых вмешательств

    Recent improvements in the development of A2B adenosine receptor agonists

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    Adenosine is known to exert most of its physiological functions by acting as local modulator at four receptor subtypes named A1, A2A, A2B and A3 (ARs). Principally as a result of the difficulty in identifying potent and selective agonists, the A2B AR is the least extensively characterised of the adenosine receptors family. Despite these limitations, growing understanding of the physiological meaning of this target indicates promising therapeutic perspectives for specific ligands. As A2B AR signalling seems to be associated with pre/postconditioning cardioprotective and anti-inflammatory mechanisms, selective agonists may represent a new therapeutic group for patients suffering from coronary artery disease. Herein we present an overview of the recent advancements in identifying potent and selective A2B AR agonists reported in scientific and patent literature. These compounds can be classified into adenosine-like and nonadenosine ligands. Nucleoside-based agonists are the result of modifying adenosine by substitution at the N6-, C2-positions of the purine heterocycle and/or at the 5′-position of the ribose moiety or combinations of these substitutions. Compounds 1-deoxy-1-{6-[N′-(furan-2-carbonyl)-hydrazino]-9H-purin-9-yl}-N-ethyl-β-D-ribofuranuronamide (19, hA1Ki = 1050 nM, hA2AKi = 1550 nM, hA2B EC50 = 82 nM, hA3Ki > 5 μM) and its 2-chloro analogue 23 (hA1Ki = 3500 nM, hA2AKi = 4950 nM, hA2B EC50 = 210 nM, hA3Ki > 5 μM) were confirmed to be potent and selective full agonists in a cyclic adenosine monophosphate (cAMP) functional assay in Chinese hamster ovary (CHO) cells expressing hA2B AR. Nonribose ligands are represented by conveniently substituted dicarbonitrilepyridines, among which 2-[6-amino-3,5-dicyano-4-[4-(cyclopropylmethoxy)phenyl]pyridin-2-ylsulfanyl]acetamide (BAY-60–6583, hA1, hA2A, hA3 EC50 > 10 μM; hA2B EC50 = 3 nM) is currently under preclinical-phase investigation for treating coronary artery disorders and atherosclerosis
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