The labile iron pool (LIP) of animal cells has been implicated in cell iron regulation and as a key component of the oxidative-stress response. A major mechanism commonly implied in the downregulation of LIP has been the induced expression of ferritin (FT), particularly the heavy subunits (H-FT) that display ferroxidase activity. The effects of H-FT on LIP and other physiological parameters wer...

. There is little doubt that the bulk of the organic matter in meteorites is indigenous, judging from isotopic measurements on C, H, and S (20, 21). Such proof is not available for individual compounds, however, and it is therefore necessary to resort to less direct arguments to rule out terrestrial contamination. We shall briefly review the most reliably established features of organic matter ...

Моделирование процесса синтеза Фишера-Тропша является довольно сложным. Существует большое разнообразие кинетических моделей, которые были разработаны для описания реакции Фишера-Тропша. В данной статье приводится математическая модель процесса, описывающая начальный период расходования СО и образования основных продуктов в присутствии железо-рутений содержащего катализатора на основе сверхсшит...

The effect of Au in the behavior of Ru as a Fischer-Tropsch catalyst was studied. Two series of catalysts were investigated, one supported on Si02 and the other on MgO. Au did not seem to alter the product distribution on Ru at pressures up to 1 MPa and in the temperature range 490-570 K. However, the turnover frequencies for both CO hydrogenation and methanation showed a precipitous drop with ...

Sequential multiple methylene (CH2) insertions into adsorbed methyl species on clean gallium-rich GaAs(100)-(4 x 1) occurs to form higher alkenes (ethene, propene, butene) and two higher alkyl iodides (iodoethane, iodopropane), not reported for a semiconductor surface previously.

Operando spectroscopic techniques (Diffusive Reflective Infrared Fourier-Transform and Mössbauer emission spectroscopy) were combined to investigate the role of oxygenates deposition on deactivation cobalt titania Fischer-Tropsch catalysts at high pressure. Clear formation carboxylates was seen for prepared via both impregnation precipitation, but more heavier impregnated catalyst. This effect ...

The widespread use of fossil fuels has caused high CO2 concentrations in the atmosphere, which have had a great impact on climate and environment. Methods for efficiently utilizing to produce value-added chemicals received increasing attention. Among products hydrogenation, olefins, an important petrochemical feedstock, are one essential target products. Therefore, hydrogenation olefins been ex...

Fischer-Tropsch synthesis is a promising route for production of light olefins via CO hydrogenation over transition metals. Co is one of the most active metals for Fischer-Tropsch synthesis. Some different variables such as preparation parameters and operational factors can strongly affect the selectivity of Fischer-Tropsch synthesis toward the special products. In the case of preparat...