Обоснование применения потокоотклоняющих технологий на Западно-Катыльгинском нефтяном месторождении (Томская область)

Объектом исследования являются нагнетательные скважины, на которых применяются потокоотклоняющие технологии для выравнивания профиля приёмистости и увеличения нефтеотдачи. Цель работы – обосновать применение потокоотклоняющих технологий на нефтяном месторождении, оценить возможность применения различных составов для выравнивания профиля приёмистости нагнетательных скважин. В процессе исследования были рассмотрены современные потокоотклоняющие технологии и наиболее благоприятные геолого-физические условия их применения.The object of the study is injection wells, which use diverting technologies to align the injectivity profile and increase oil recovery. The purpose of the work is to justify the use of flow diverting technologies in an oil field, to assess the possibility of using various compositions to align the injectivity profile of injection wells. During the study, modern flow diverting technologies and the most favorable geological and physical conditions for their application were considered

Human Neurospheres as Three-Dimensional Cellular Systems for Developmental Neurotoxicity Testing

Bac k g r o u n d: Developmental neurotoxicity (DNT) of environmental chemicals is a serious threat to human health. Current DNT testing guidelines propose investigations in rodents, which require large numbers of animals. With regard to the “3 Rs ” (reduction, replacement, and refinement) of animal testing and the European regulation of chemicals [Registration, Evaluation, and Authorisation of Chemicals (REACH)], alternative testing strategies are needed in order to refine and reduce animal experiments and allow faster and less expensive screening. Objectives: The goal of this study was to establish a three-dimensional test system for DNT screening based on human fetal brain cells. Met h o d s: We established assays suitable for detecting disturbances in basic processes of brain development by employing human neural progenitor cells (hNPCs), which grow as neurospheres. Furthermore, we assessed effects of mercury and oxidative stress on these cells. Re s u l t s: We found that human neurospheres imitate proliferation, differentiation, and migration in vitro. Exposure to the proapoptotic agent staurosporine further suggests that human neurospheres possess functioning apoptosis machinery. The developmental neurotoxicants methylmercury chloride and mercury chloride decreased migration distance and number of neuronal-like cells in differentiated hNPCs. Furthermore, hNPCs undergo caspase-independent apoptosis when exposed toward high amounts of oxidative stress. Co n c l u s i o n s: Human neurospheres are likely to imitate basic processes of brain development, and these processes can be modulated by developmental neurotoxicants. Thus, this three-dimensional cell system is a promising approach for DNT testing. Key w o r d s: apoptosis, differentiation, DNT, human neurospheres, mercury, migration, proliferation. Environ Health Perspect 117:1131–1138 (2009). doi:10.1289/ehp.0800207 available vi

Bioactive Semisynthetic Dervatives of (S)-(+)-Curcuphenol

8 pages, figures, and tables statistics.New semisynthetic sesquiterpene derivatives (3-7, 10), together with two known ones (8-9) were prepared from (S)-(+)- curcuphenol (1), isolated from the Caribbean sponge Didiscus oxeata. The natural sesquiterpenes 1 and (S)-(+)-curcudiol (2), as well as semisynthetic derivatives 3-10, were evaluated against the herbivorous insect species Spodoptera littoralis, Leptinotarsa decemlineata and Rhopalosiphum padi. All compounds had an antifeedant effect on L. decemlineata. With R. padi, a structure-dependent antifeedant response was observed, with 1 being the most active, followed by 4 and 5. Furthermore, compounds 1, 4, 5, 7, 8 and 10 reduced S. littoralis larval weight, with 10 also reducing ingestion by S. littoralis larvae. Of the derivatives studied here, none showed stronger effects (either antifeedant or postingestive) than the parent compound 1. It can, therefore, be concluded that the structure of the side chain and the presence of the phenol ring of curcuphenol are important structural requirements for its insect antifeedant and growth regulation effects.Peer reviewe

BDE-47 and 6-OH-BDE-47 modulate calcium homeostasis in primary fetal human neural progenitor cells via ryanodine receptor-independent mechanisms

Polybrominated diphenyl ethers (PBDEs) are bioaccumulating flame retardants found in rising concentrations in human tissue. Epidemiological and animal studies have raised concern for their potential to induce developmental neurotoxicity (DNT). Considering the essential role of calcium homeostasis in neurodevelopment, PBDE-induced disturbance of intracellular calcium concentration ([Ca2+]i) may underlie PBDE-induced DNT. To test this hypothesis, we investigated acute effects of BDE-47 and 6-OH-BDE-47 on [Ca2+]i in human neural progenitor cells (hNPCs) and unraveled involved signaling pathways. Short-time differentiated hNPCs were exposed to BDE-47, 6-OH-BDE-47, and multiple inhibitors/stimulators of presumably involved signaling pathways to determine possible effects on [Ca 2+]i by single-cell microscopy with the fluorescent dye Fura-2. Initial characterization of calcium signaling pathways confirmed the early developmental stage of hNPCs. In these cells, BDE-47 (2 μM) and 6-OH-BDE-47 (0.2 μM) induce [Ca2+]i transients. This increase in [Ca2+]i is due to extracellular Ca 2+ influx and intracellular release of Ca2+, mainly from the endoplasmic reticulum (ER). While extracellular Ca2+ seems to enter the cytoplasm upon 6-OH-BDE-47 by interfering with the cell membrane and independent of Ca2+ ion channels, ER-derived Ca2+ is released following activation of protein lipase C and inositol 1,4,5-trisphosphate receptor, but independently of ryanodine receptors. These findings illustrate that immature developing hNPCs respond to low concentrations of 6-OH-BDE-47 by an increase in [Ca2+]i and provide new mechanistic explanations for such BDE-induced calcium disruption. Thus, these data support the possibility of a critical window of PBDE exposure, i.e., early human brain development, which has to be acknowledged in risk assessment