Small HSPs molecular weights as new indication to the hypothesis of segregated status of thermophilic relict Gmelinoides fasciatus among baikal and palearctic amphipods

Among the great diverse of Baikal fauna of amphipods (more than 350 species and subspecies) Gmelinoides fasciatus (Stebbing 1899) takes the special place. It is characterized by a high morphological variability and wide thermal-adaptive possibilities. By common opinion G. fasciatus is a thermophilic relict segregated from other Baikal temperature sensitive amphipods' fauna. In present study we tested hypothesis of segregated status of G. fasciatus among some Baikal and some Palearctic amphipods using of heat-shock proteins’ (HSP) molecular weight as comparative biomarkers. We used heat-shock proteins (HSP) from two families: HSP70 and small HSP (sHSP) immunochemically related to α-crystalline. 15 species of Baikal amphipods from different genera and families and 2 Palearctic species from genus Gammarus were tested. It was shown, that molecular weights of HSP70 were the same in all investigated species and corresponds close to 70 kD. In the contrast, the molecular weights of sHSP in G. fasciatus was 37 kD and differed from all other species, in which molecular weights of sHSP were 35 kD. In sum, this study showed that sHSPs molecular weights may relate to evolutional differences between the close related species. Additionally, obtained data can be taken as new indication of segregated status of thermophilic relict G. fasciatus which linked with its phylogenetic history in Lake Baikal

До 60-річчя від дня народження професора А.В. Єни

60-th anniversary of professor A.V. Yen

Пам’яті Михайла Загульського

The Mikhaylo Zahul’sky long memor

Автоэмиссионные свойства пленок никель - углеродного нанокомпозита

Field-emission properties of Ni-C nanocomposite thin films were experimentally studied. The films were deposited at Si substrates using CVD technique with a metalloorganic precursor and were composed by nm-scale grains of metallic Ni bounded with a carbonic weakly-conducting matrix. In the samples with lower effective thickness, the Ni particles were separated from each other. Such films showed capability of facilitated emission with threshold field values as low as a few V/μm. Thicker coating samples, with metallic particle merged in a conductive layer, required annealing at 470-600 °С in vacuum to produce low-field emission current. The observed emission behavior agrees with the previously proposed model considering low-field emission from nanostructured carbonic materials as a multi-stage process involving generation of hot electrons at interface boundaries.Были исследованы автоэмиссионные свойства тонких пленок никель-углеродного нанокомпозита. Пленки наносились на кремниевые подложки методом химического осаждения с использованием металлорганического прекурсора. Их структура включала в себя наноразмерные зерна металлического никеля, связанные слабопроводящей углеродосодержащей матрицей. В случае покрытий малой эффективной толщины, частицы никеля были отделены друг от друга. Такие пленки демонстрировали способность к низковольтной эмиссии в полях с напряженностью от нескольких В/мкм. В более толстых покрытиях металлические частицы образовывали единый электропроводящий слой. В этом случае для наблюдения низковольтной эмиссии требовался отжиг образцов в вакууме при 470-600 °С. Наблюдавшиеся закономерности эмиссии согласуются с предлагавшейся ранее моделью, которая рассматривает низковольтную эмиссию из наноуглеродных материалов как многостадийный процесс с участием горячих электронов, образующихся на внутренних междоменных границах

COMPARISON OF STRESS PROTEINS PARTICIPATION IN ADAPTATION MECHANISMS OF BAIKALIAN AND PALEARCTIC AMPHIPOD (AMPHIPODA; CRUSTACEA) SPECIES

The aim of the present study was a study of the influence different stressful factor on syntheses and activity of the stress proteins (HSP70, sHSP and peroxidase) of freshwater organism. Six freshwater amphipod species were investigated: Eulimnogammarus cyaneus (Dyb.), E verrucosus (Gerstf.), E vittatus (Dyb.) - endemic species from Lake Baikal which were compared with Palearctic species - Gammarus lacustris Sars., G tigrinus (Sexton), Chaetogammarus ischnus (Stebbins). It was shown expression of sHSP by heat and toxic stresses for all amphipods species. Oxidative stress induced HSP70 for Palearctic species G tigrinus and C ischnus but not for baikalian species. Heat stress did not caused the increase of HSP70 level for Baikalian species of amphipods. The activity of the peroxidase was decrease by heat and toxic stresses. Oxidative stress caused the increase of peroxidase activity for Palearctic species, and the decrease for Baikalian once