Гепатозащитная эффективность производных пиримидина при острой интоксикации дихлорэтаном

The paper presents the results of a study of the antioxidative and hematoprotective properties of pyrimidine derivatives: 1,3,6-trimethyl-5-hydroxyuracil and 3,6-dimethyl-5-hydrpxyuracil versus the synthetic antioxidant tonarol, а-tocopherol acetate, and the antihypoxant ethomerzole. In model systems of varying complexity, the antiradical activity of pyrimidines and their effects on spontaneous, ascorbate- and NADPH-dependent lipid peroxidation processes, as well as their protective activity were studied in different types of hypoxia. The pyrimidine derivatives were found to have the high antioxidative activity comparable with that of ionol. 1,3,6-trimethyl-5-hydroxyuracil has antihypoxic activity. Dichloroethane induced acute toxic hepatitis whose major manifestations were cytolysis, cholestasis, lipid metabolic disturbances, and an activated lipid peroxidation response. 1,3,6-trimethyl-5-hydroxyuracil limits the cytotoxic and cholestatic activity of dichloroethane, stabilizes lipid metabolism and lipid peroxidation reactions, and increases life span and survival in rats. Представлены результаты исследования антиоксидантных, антиокислительных, гепатопротекторных свойств пиримиди-новых производных: 1,3,6-триметил-5-гидроксиурацила и 3,6-диметил-5-гидроксиурацила в сравнении с синтетическим антиоксидантом тонаролом, ацетат-а-токоферолом и антигипоксантом этомерзолом. В модельных системах различной сложности исследованы антирадикальная активность пиримидинов, их влияние на процессы спонтанного, аскорбат- и NADPH-зависимого перекисного окисления липидов, а также защитный эффект при различных видах гипоксии. Установлена высокая антиоксидантная активность производных пиримидина, сопоставляемая с ионолом. Соединение 1,3,6-триметил-5-гидроксиурацил обладает антигипоксическим действием. Дихлорэтан вызывает развитие острого токсического гепатита, основным проявлением которого являются цитолиз, холестаз, нарушение липидного обмена, активация реакции перекисного окисления липидов. Соединение 1,3,6-триметил-5-гидроксиурацил ограничивает цитотоксическое и холестатическое действие дихлорэтана, стабилизирует липидный обмен и реакции перекисного окисления липидов, увеличивает продолжительность жизни и выживаемость крыс.

Fundamental Limits on Wavelength, Efficiency and Yield of the Charge Separation Triad

In an attempt to optimize a high yield, high efficiency artificial photosynthetic protein we have discovered unique energy and spatial architecture limits which apply to all light-activated photosynthetic systems. We have generated an analytical solution for the time behavior of the core three cofactor charge separation element in photosynthesis, the photosynthetic cofactor triad, and explored the functional consequences of its makeup including its architecture, the reduction potentials of its components, and the absorption energy of the light absorbing primary-donor cofactor. Our primary findings are two: First, that a high efficiency, high yield triad will have an absorption frequency more than twice the reorganization energy of the first electron transfer, and second, that the relative distance of the acceptor and the donor from the primary-donor plays an important role in determining the yields, with the highest efficiency, highest yield architecture having the light absorbing cofactor closest to the acceptor. Surprisingly, despite the increased complexity found in natural solar energy conversion proteins, we find that the construction of this central triad in natural systems matches these predictions. Our analysis thus not only suggests explanations for some aspects of the makeup of natural photosynthetic systems, it also provides specific design criteria necessary to create high efficiency, high yield artificial protein-based triads

Evaluation of onboard radiometric system for remote sensing detection of heightened radioactivity of soil

A remote sensing method of monitoring heightened soil radioactivity using an onboard radiometer that records indirect effects in the environment is examined. The gamma-spectrometric field surveying was used to determine the soil content of uranium, thorium, and potassium in southeastern Tomsk. Heightened uranium content was found in soil samples from Kuzovlevo village, Nadezhda village, TGOK Il'menit and high thorium in samples from Svetloe village, and Aleksandrrov section of TGOK Ilmenit, Kuskovo City, and Zorkal'tsevo Village. The energy spectra and average characteristics of the beta-decay electrons of potassium-40 in soil were obtained