179 research outputs found
Chemical kinetic theory of aging
A theory of aging based on the principles of the kinetics of chemical
reactions and the rules of natural selection of organisms is proposed. The
theory is based on a hypothesis that the biochemical processes in the organism
can be described in the terms of chemical reaction kinetics. The evolutionary
process of organisms is determined by the goal of continuing life, and the
natural selection forced organisms to develop in an optimized way for survival
and reproduction, after which any further development of the organisms did not
matter for natural selection and therefore was not regulated by it.
Accordingly, the ongoing biochemical processes in the organism after giving
birth were not stabilised and continued casual, which, in the case of complex
systems of biochemical processes, led to imbalances and biochemical processes
that did not contribute to health in the organism, resulting in aging. Based on
this view, it is necessary to look for the key biochemical processes that
regulate the vital activity of the organism. Balancing of these processes in
the period after giving birth can artificially lead to the stabilization of the
kinetics of biochemical reactions, and consequently, the continuation of life
almost indefinitely
Indexes Objectively Reflecting Performance Evaluation of Technical Rubber Goods
AbstractIn order to choose a characteristic index which objectively reflects performance evaluation of technical rubber goods, accelerated thermal-oxidative ageing of rubbers was carried out. It has been demonstrated that as the index accountable for maintaining workability the rate of set at compressing or tension relaxing at pressing of technical rubber goods in a statically deformed state is usually taken. Besides, breaking elongation or tensile strength of technical rubber goods in a free state can be taken as an index, as well. It has been educed that the most sensitive index which reflexes the structural changes in the rubber of the rubber-cord casing (RCC) during the process of ageing is breaking elongation, the value of which is drastically dropping in the initial period of the thermal ageing and monotonously changing thereafter
Composite Materials With Uncured Epoxy Matrix Exposed in Stratosphere During NASA Stratospheric Balloon Flight
A cassette of uncured composite materials with epoxy resin matrixes was exposed in the stratosphere (40 km altitude) over three days. Temperature variations of -76 to 32.5C and pressure up to 2.1 torr were recorded during flight. An analysis of the chemical structure of the composites showed, that the polymer matrix exposed in the stratosphere becomes crosslinked, while the ground control materials react by way of polymerization reaction of epoxy groups. The space irradiations are considered to be responsible for crosslinking of the uncured polymers exposed in the stratosphere. The composites were cured on Earth after landing. Analysis of the cured composites showed that the polymer matrix remains active under stratospheric conditions. The results can be used for predicting curing processes of polymer composites in a free space environment during an orbital space flight
Biospectroscopy of Nanodiamond-Induced Alterations in Conformation of Intra- and Extracellular Proteins: A Nanoscale IR Study
The toxicity of nanomaterials raises major concerns because of the impact that nanomaterials may have on health,
which remains poorly understood. We need to explore the fate of individual nanoparticles in cells at nano and molecular levels to
establish their safety. Conformational changes in secondary protein structures are one of the main indicators of impaired biological
function and hence, the ability to identify these changes at a nanoscale level offers unique insights into the nanotoxicity of materials.
Here, we used nanoscale infrared spectroscopy and demonstrated for the first time that nanodiamonds induced alterations in
both extra- and intracellular secondary protein structures, leading to the formation of antiparallel β-sheet, β-turns, intermolecular β-
sheet and aggregation of proteins. These conformational changes of the protein structure may result in the loss of functionality of
proteins and in turn lead to adverse effects
Mechanisms for covalent immobilization of horseradish peroxi-dase on ion beam treated polyethylene
The mechanism that provides the observed strong binding of biomolecules to
polymer sur-faces modified by ion beams is investigated. The surface of
polyethylene (PE) was modified by plasma immersion ion implantation with
nitrogen ions. Structure changes including car-bonization and oxidation were
observed in the modified surface layer of PE by Raman spec-troscopy, FTIR ATR
spectroscopy, atomic force microscopy, surface energy measurement and XPS
spectroscopy. An observed high surface energy of the modified polyethylene was
attributed to the presence of free radicals on the surface. The surface energy
decay with stor-age time after PIII treatment was explained by a decay of the
free radical concentration while the concentration of oxygen-containing groups
increased with storage time. Horseradish per-oxidase was covalently attached
onto the modified PE surface. The enzymatic activity of co-valently attached
protein remained high. A mechanism based on the covalent attachment by the
reaction of protein with free radicals in the modified surface is proposed.
Appropriate blocking agents can block this reaction. All aminoacid residues can
take part in the covalent attachment process, providing a universal mechanism
of attachment for all proteins. The long-term activity of the modified layer to
attach protein (at least 2 years) is explained by stabilisa-tion of unpaired
electrons in sp2 carbon structures. The native conformation of attached
pro-tein is retained due to hydrophilic interactions in the interface region. A
high concentration of free radicals on the surface can give multiple covalent
bonds to the protein molecule and de-stroy the native conformation and with it
the catalytic activity. The universal mechanism of protein attachment to free
radicals could be extended to various methods of radiation damage of polymers
Development and Implementation of a Program for the Formation of Project Culture Among the Fighters of Student Detachments
Рассмотрены основополагающие навыки и компетенции, которые включает в себя проектная культура. Предложена структура программы по формированию проектной культуры у бойцов студенческих отрядов, состоящая из трех модулей: информационного, интерактивного, проектного. Представлены итоги реализации информационного модуля программы по формированию проектной культуры у участников (студентов) из экспериментальной группы. Показано, что реализация модуля программы повысила уровень сформированности навыка — креативное решение.The article discusses the fundamental skills and competencies that the project culture includes. The structure of the program for the formation of project culture among the fighters of student detachments, consisting of three modules: informational, interactive, project. The results of the implementation of the information module of the program on the formation of project culture among participants (students) from the experimental group are presented. It is shown that the implementation of the program module has increased the level of skill formation — a creative solution
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