56 research outputs found
Анализ причин обводненности добывающих скважин на нефтяных месторождениях
В процессе исследования рассмотрены причины преждевременного обводнения скважин, алгоритм подбора скважин-кандидатов для проведения водоизоляционных работ (ВИР), методы диагностики водопритоков, факторы, влияющие на эффективность ВИР и мероприятия по снижению обводненности скважинной продукции. Рассмотрен опыт применения технологии выравнивания профиля приемистости на месторождении АО "Газпромнефть-ННГ".During the research, the causes of premature well flooding, the algorithm for selecting candidate wells for water shutoff, methods for diagnosing water inflow, factors affecting the effectiveness of water shutoff and measures to reduce the water content of well products are considered. The experience of applying the technology of conformance control at the field of JSC Gazpromneft-NNG is considered
Role of TRAIL and the pro-apoptotic Bcl-2 homolog Bim in acetaminophen-induced liver damage
Acetaminophen (N-acetyl-para-aminophenol (APAP), paracetamol) is a commonly used analgesic and antipyretic agent. Although considered safe at therapeutic doses, accidental or intentional overdose causes acute liver failure characterized by centrilobular hepatic necrosis with high morbidity and mortality. Although many molecular aspects of APAP-induced cell death have been described, no conclusive mechanism has been proposed. We recently identified TNF-related apoptosis-inducing ligand (TRAIL) and c-Jun kinase (JNK)-dependent activation of the pro-apoptotic Bcl-2 homolog Bim as an important apoptosis amplification pathway in hepatocytes. In this study, we, thus, investigated the role of TRAIL, c-JNK and Bim in APAP-induced liver damage. Our results demonstrate that TRAIL strongly synergizes with APAP in inducing cell death in hepatocyte-like cells lines and primary hepatocyte. Furthermore, we found that APAP strongly induces the expression of Bim in a c-JNK-dependent manner. Consequently, TRAIL- or Bim-deficient mice were substantially protected from APAP-induced liver damage. This study identifies the TRAIL-JNK-Bim axis as a novel target in the treatment of APAP-induced liver damage and substantiates its general role in hepatocyte death
Анализ конкурентоспособности предприятия на рынке телекоммуникационных услуг
В результате исследования дана характеристика рынка телекоммуникационных услуг, определены методики оценки конкурентоспособности услуг и товаров предприятия, выявлены факторы, определяющие конкурентоспособность товаров и услуг, представлены особенности конкуренции на рынке телекоммуникационных услуг, дана характеристика деятельности компании ПАО "Ростелеком", проведен анализ конкурентоспособности ПАО "Ростелеком" и предоставляемых услуг, выполнена разработка мероприятий по повышению конкурентоспособности предприятия.As a result of the research, the characteristics of the telecommunications services market are given, the methods for assessing the competitiveness of services and goods of the enterprise are defined, the factors determining the competitiveness of goods and services are identified, the features of competition in the telecommunications market are presented, the performance of the company PJSC "Rostelecom" is given, the competitiveness analysis of PJSC "Rostelecom" "And the services provided, the development of measures to increase the competitiveness of the enterpris
TAK1 Is Required for Survival of Mouse Fibroblasts Treated with TRAIL, and Does So by NF-κB Dependent Induction of cFLIPL
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is known as a “death ligand”—a member of the TNF superfamily that binds to receptors bearing death domains. As well as causing apoptosis of certain types of tumor cells, TRAIL can activate both NF-κB and JNK signalling pathways. To determine the role of TGF-β-Activated Kinase-1 (TAK1) in TRAIL signalling, we analyzed the effects of adding TRAIL to mouse embryonic fibroblasts (MEFs) derived from TAK1 conditional knockout mice. TAK1−/− MEFs were significantly more sensitive to killing by TRAIL than wild-type MEFs, and failed to activate NF-κB or JNK. Overexpression of IKK2-EE, a constitutive activator of NF-κB, protected TAK1−/− MEFs against TRAIL killing, suggesting that TAK1 activation of NF-κB is critical for the viability of cells treated with TRAIL. Consistent with this model, TRAIL failed to induce the survival genes cIAP2 and cFlipL in the absence of TAK1, whereas activation of NF-κB by IKK2-EE restored the levels of both proteins. Moreover, ectopic expression of cFlipL, but not cIAP2, in TAK1−/− MEFs strongly inhibited TRAIL-induced cell death. These results indicate that cells that survive TRAIL treatment may do so by activation of a TAK1–NF-κB pathway that drives expression of cFlipL, and suggest that TAK1 may be a good target for overcoming TRAIL resistance
Cell-Intrinsic NF-κB Activation Is Critical for the Development of Natural Regulatory T Cells in Mice
regulatory T (Treg) cells develop in the thymus and represent a mature T cell subpopulation critically involved in maintaining peripheral tolerance. The differentiation of Treg cells in the thymus requires T cell receptor (TCR)/CD28 stimulation along with cytokine-promoted Foxp3 induction. TCR-mediated nuclear factor kappa B (NF-κB) activation seems to be involved in differentiation of Treg cells because deletion of components of the NF-κB signaling pathway, as well as of NF-κB transcription factors, leads to markedly decreased Treg cell numbers in thymus and periphery. thymic Treg precursors and their further differentiation into mature Treg cells. Treg cell development could neither be completely rescued by the addition of exogenous Interleukin 2 (IL-2) nor by the presence of wild-type derived cells in adoptive transfer experiments. However, peripheral NF-κB activation appears to be required for IL-2 production by conventional T cells, thereby participating in Treg cell homeostasis. Moreover, pharmacological NF-κB inhibition via the IκB kinase β (IKKβ) inhibitor AS602868 led to markedly diminished thymic and peripheral Treg cell frequencies.Our results indicate that Treg cell-intrinsic NF-κB activation is essential for thymic Treg cell differentiation, and further suggest pharmacological NF-κB inhibition as a potential therapeutic approach for manipulating this process
Recommended from our members
Dietary α‐Linolenic Acid, Marine ω‐3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvención con DIeta MEDiterránea (PREDIMED) Study
Background: Epidemiological evidence suggests a cardioprotective role of α‐linolenic acid (ALA), a plant‐derived ω‐3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine ω‐3 fatty acids (long‐chain n‐3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to all‐cause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for long‐chain n‐3 polyunsaturated fatty acids (≥500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvención con DIeta MEDiterránea (PREDIMED) trial. Multivariable‐adjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9‐y follow‐up, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56–0.92) for all‐cause mortality and 0.95 (95% CI 0.58–1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for long‐chain n‐3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67–1.05) for all‐cause mortality, 0.61 (95% CI 0.39–0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29–0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22–1.01) for sudden cardiac death. The highest reduction in all‐cause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45–0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to all‐cause mortality, whereas protection from cardiac mortality is limited to fish‐derived long‐chain n‐3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639
Phytoplanktonic biomass synthesis: application to deviations from Redfield stoichiometry
17 páginas, 9 figuras, 6 tablas.-- Publicación online disponible en: http://www.icm.csic.es/scimar/index.phpDuring biomass formation as a result of phytoplankton photosynthesis, CO2 and the nutrients NO3 and PO4 are consumed and O2 produced in fixed proportions known as the Redfield ratio. Broecker’s tracers, i.e., “NO” = O2+RN·NO3, “PO” =O2+RP·PO4, and “CO” = O2+RC·CO2, remain constant during photosynthesis, because nutrients consumed are offset by O2 formation. When one or several nutrients become depleted, the Redfield ratio no longer holds, and the tracers cease to remain constant. The main causes are formation of excess carbohydrates or lipids, N2 fixation, or production of CaCO3 plates by phytoplanktonic populations that have developed different strategies for obtaining the nutrients they need. This paper presents new tracers that remain constant, irrespective of whether or not Redfield stoichiometry is satisfied. Differences between the values of the new tracers and the values of the conventional tracers reveal the presence of anomalies in biomass production. They also allow quantification of any such anomalies, both globally and by depth stratum, and assessment of each individual anomaly separately, even when more than one anomaly occur simultaneously.Peer reviewe
Interplay among cardiotrophin-1, prostaglandins, and vascular endothelial growth factor in rat liver regeneration
Prostaglandins are hepatoprotective molecules generated in liver regeneration by the rapid induction of cyclooxygenase-2 (COX-2). Cardiotrophin-1 (CT-1) and vascular endothelial growth factor (VEGF) are other hepatoprotective mediators upregulated at 24 hours after partial hepatectomy. The interactions among these molecules during liver regeneration have not yet been defined. Here we show that rats subjected to partial hepatectomy treated with NS-398, a specific COX-2 inhibitor, exhibited cell cycle arrest, increased hepatocyte apoptosis, persistent extracellular signal-regulated kinase (ERK) 1/2 activation, and increased interleukin-6 production. These changes were associated with downregulation of CT-1 and COX-1 and altered pattern of VEGF expression. Administration of an adenovirus encoding CT-1 to NS-398-treated rats restituted normal levels of COX-1, prostaglandins, and VEGF in the liver after partial hepatectomy and restored normal liver regeneration. Furthermore, the stimulation of isolated rat hepatocytes with CT-1 increased COX-1, COX-2, and VEGF messenger RNAs and prostaglandin synthesis. Conversely, the addition of prostaglandin E1 to the culture increased CT-1 and VEGF production. In conclusion, COX-2 activation and production of prostaglandins soon after partial hepatectomy are essential requirements for hepatocyte proliferation and for the correct induction of both CT-1 and VEGF. CT-1 can restore liver regeneration after COX-2 inhibition by increasing VEGF, COX-1 expression, and prostaglandin synthesis
- …