Some Molecular and Cellular Stress Mechanisms Associated with Neurodegenerative Diseases and Atherosclerosis

Chronic stress is a combination of nonspecific adaptive reactions of the body to the influence of various adverse stress factors which disrupt its homeostasis, and it is also a corresponding state of the organism’s nervous system (or the body in general). We hypothesized that chronic stress may be one of the causes occurence of several molecular and cellular types of stress. We analyzed literary sources and considered most of these types of stress in our review article. We examined genes and mutations of nuclear and mitochondrial genomes and also molecular variants which lead to various types of stress. The end result of chronic stress can be metabolic disturbance in humans and animals, leading to accumulation of reactive oxygen species (ROS), oxidative stress, energy deficiency in cells (due to a decrease in ATP synthesis) and mitochondrial dysfunction. These changes can last for the lifetime and lead to severe pathologies, including neurodegenerative diseases and atherosclerosis. The analysis of literature allowed us to conclude that under the influence of chronic stress, metabolism in the human body can be disrupted, mutations of the mitochondrial and nuclear genome and dysfunction of cells and their compartments can occur. As a result of these processes, oxidative, genotoxic, and cellular stress can occur. Therefore, chronic stress can be one of the causes forthe occurrence and development of neurodegenerative diseases and atherosclerosis. In particular, chronic stress can play a large role in the occurrence and development of oxidative, genotoxic, and cellular types of stress.     

The Superconducting Bismuth-Based Mixed Oxides

The present paper describes the synthesis, characterization of mixedvalence bismuthates with 3- or 2-dimensional perovskite-like structures and structural criteria that influence superconductivity in these compounds. Single phase samples of Sr_1–x K _x BiO₃ were prepared for the broad range of K-content: 0.25x0.65. For these bismuthates the symmetry of the structure changes from monoclinic to orthorhombic and finally to tetragonal upon increasing the K-content thus resulting in the decrease of the Bi-O distances and reduction of the network distortions. Superconductivity with maximum T _c=12K exists in the narrow range (x0.5–0.6) within the stability field of the tetragonal phase (0.33x0.65), when the 3-dimensional octahedral framework has close to the ideal perovskite structure arrangement. At the same time compositions with close to optimal Bi-valence (x=0.33 and 0.43) do not show any sign of superconductivity, probably, due to structural distortions. The layered type (Ba, K)₃Bi₂O₇ and (Ba, K)₂BiO₄ bismuthates belonging to the A _n+1B _n O_3n+1 homologous series were investigated. Buckling of the (BiO₂) layers in the structure of the n=2 member was revealed. The formation of the n=1 bismuthate was found by Electron Microscopy and X-ray powder diffraction studies. Both types of compounds are considered to be possible candidates for new superconducting materials among bismuthates.     

Sorption of Np(V), Pu(V), and Pu(IV) on colloids of Fe(III) oxides and hydrous oxides and MnO<Subscript>2</Subscript>

Sorption of Np(V), Pu(V), and Pu(IV) on colloids of synthetic goethite (α-FeOOH), hematite (α-Fe₂O₃), maghemite (γ-Fe₂O₃), and amorphous MnO₂ was studied over wide ranges of solution pH and ionic strength by solvent extraction and X-ray photoelectron spectroscopy (XPS). Plutonium(V) is reduced upon sorption on α-FeOOH, but not on α-Fe₂O₃ and γ-Fe₂O₃. On the MnO₂ surface, Pu occurs as Pu(VI). From the pH dependences of the actinide sorption, the equilibrium constants of the reactions of Np(V)O ₂ ⁺ and Pu(V)O ₂ ⁺ with the surface hydroxy groups of the investigated colloid particles and a set of the equilibrium constants of the reactions of Pu(IV) hydroxo complexes with α-FeOOH were obtained. If no redox reactions occur on the surface of the colloid particles, these constants decrease in the order \(K_{MnO_2 } > K_{\alpha - FeOOH} > K_{\alpha - Fe_2 O_3 } \sim K_{\gamma - Fe_2 O_3 } \).     

Effectiveness of combined action of vitamins A, E and C and cyclophosphane or adriamycin on growth of transplanted tumors in mice

The antitumour, antimetastatic and antileukemic effect of cyclophosphane and adriamycin in combination with vitamins A. E. C was studied according to the scheme developed by the authors. The preliminary administration of vitamins was established to intensify the effect of cytostatics and to lower considerably their toxic action. Cyclophosphane proved to be more effective relative to the Lewis lung carcinoma than adriamycin.     

Effect of solcoseryl on oxygen metabolism and growth of experimental tumors

Antihypoxant and antitumour properties of solcoseryl were studied on intact and tumour-bearing rats and mice. By the polarographic method it is found that solcoseryl increases the oxygen metabolism only in animal hypoxic tissues and improves, probably, energy production of their mitochondria. On many tumour strains it is shown that the injections of solcoseryl decelerate the growth of some tumours, inhibit the metastatic process and produce no toxic effect on the animals.     

Transparent colors for glass decoration

Translated from Steklo i Keramika, No. 11, p. 18, November, 1990.     

Ceramics Based on CaSO4⋅2H2O Powder Synthesized from Ca(NO3)2 and (NH4)2SO4

Inorganic Materials - Ceramics consisting of anhydrous calcium sulfate, CaSO4, after firing in the range 800–1000°C have been prepared from calcium sulfate dihydrate (CaSO4?2H2O)...     

A study of propane aromatization on a zeolite-containing catalyst with different Si/Al ratios

The results of studying the effect of the aluminum content and the Si/Al molar ratio of zeolite-containing catalysts on their activity and the yield of aromatic hydrocarbons in propane conversion at a degree of conversion of 60–70 wt % are described.     

Simulation of the Behavior of Activated Products of Corrosion during RBMK-1000 Startup after Scheduled Major Overhaul

A simple model is proposed for calculating the activation of corrosion products during startup and under normal operation conditions of a reactor. The model parameters, such as the rate of removal of radionuclides from the loop and the wash-off and deposition constants of radionuclides in the reactor core, are determined for certain radionuclides.It is shown that the removal rate of activated corrosion products is 3–10 times higher than previously assumed, and is (2.4–6)·10^–4 sec^–1 for ⁵¹Cr and (7.5–10)·10^–4 sec^–1 for ⁶⁰Co. The removal of ⁵¹Cr from a forced multiple circulation loop as a result of the higher solubility of this radionuclide is determined primarily by bypass purification, and the removal of ⁶⁰Co is determined primarily by removal with steam and subsequent purification of the condensate. The model calculations agree satisfactorily with observations.     

An XPS study of interaction of neptunyl(V) in aqueous solution with goethite (α-FeOOH)

Sorption and physicochemical state of Np on the goethite (-FeOOH) surface were studied. The oxidation state of Np on the -FeOOH surface was studied by the liquid extraction. The neptunium complexes formed on the surface were studied by X-ray photoelectron spectroscopy. The ionic and elemental composition of the goethite surface and NpO ₂ ⁺ complexes with -FeOOH were determined from the XPS data. No Np(IV) and Np(VI) compounds were detected. Neptunyl(V) Np(V)O ₂ ⁺ forms complexes with the surface groups of -FeOOH. The equatorial plane of these complexes is occupied by the oxygen atoms of -FeOOH and water and/or carbonate group CO ₃ ^2– .Translated from Radiokhimiya, Vol. 46, No. 6, 2004, pp. 503–506.Original Russian Text Copyright © 2004 by Yu. Teterin, Kalmykov, Novikov, Sapozhnikov, Vukcevic, A. Teterin, Maslakov, Utkin, Khasanova, Shcherbina.