234 research outputs found
The role of physical perfection in personal development
It’s very important to understand the necessity of physical improvement, as harmonious development of all parties of human life. Health is the main result of physical improvement. The highest point of development human’s health is a reference healthОчень важно понимать необходимость физического совершенствования, как гармоничного развития всех сторон человеческой жизни. Главным результатом физического совершенствования является здоровье. Наивысшая точка развития здоровья человека – эталонное здоровь
Structural and thermodynamic insight into the process of “weak” dimerization of the ErbB4 transmembrane domain by solution NMR
AbstractSpecific helix–helix interactions between the single-span transmembrane domains of receptor tyrosine kinases are believed to be important for their lateral dimerization and signal transduction. Establishing structure–function relationships requires precise structural-dynamic information about this class of biologically significant bitopic membrane proteins. ErbB4 is a ubiquitously expressed member of the HER/ErbB family of growth factor receptor tyrosine kinases that is essential for the normal development of various adult and fetal human tissues and plays a role in the pathobiology of the organism. The dimerization of the ErbB4 transmembrane domain in membrane-mimicking lipid bicelles was investigated by solution NMR. In a bicellar DMPC/DHPC environment, the ErbB4 membrane-spanning α-helices (651–678)2 form a right-handed parallel dimer through the N-terminal double GG4-like motif A655GxxGG660 in a fashion that is believed to permit proper kinase domain activation. During helix association, the dimer subunits undergo a structural adjustment (slight bending) with the formation of a network of inter-monomeric polar contacts. The quantitative analysis of the observed monomer–dimer equilibrium provides insights into the kinetics and thermodynamics of the folding process of the helical transmembrane domain in the model environment that may be directly relevant to the process that occurs in biological membranes. The lipid bicelles occupied by a single ErbB4 transmembrane domain behave as a true (“ideal”) solvent for the peptide, while multiply occupied bicelles are more similar to the ordered lipid microdomains of cellular membranes and appear to provide substantial entropic enhancement of the weak helix–helix interactions, which may be critical for membrane protein activity
Project management in academic physical education system: benefits analysis
Objective of the study was to analyze benefits of a project management technology for the modern academic physical education syste
Academic physical education benefits for faculty/ research/ management personnel’s progress agendas: survey and analysis
Objective of the study was to survey and analyze the academic physical education service benefits for the faculty/ research/ management staf
Academic physical education system: questionnaire survey to rate student satisfaction
Objective of the study was to analyze the student satisfaction with the academic physical education servic
LC nanocomposites: induced optical singularities, managed nano/micro structure, and electrical conductivity
Microstructure, phase transitions, electrical conductivity, and optical and
electrooptical properties of multiwalled carbon nanotubes (NTs), dispersed in
the cholesteric liquid crystal (cholesteryl oleyl carbonate, COC), nematic 5CB
and their mixtures, were studied in the temperature range between 255 K and 363
K. The relative concentration X=COC/(COC+5CB)was varied within 0.0-1.0. The
concentration of NTs was varied within 0.01-5% wt. The value of X
affected agglomeration and stability of NTs inside COC+5CB. High-quality
dispersion, exfoliation, and stabilization of the NTs were observed in COC
solvent ("good" solvent). From the other side, the aggregation of NTs was very
pronounced in nematic 5CB solvent ("bad" solvent). The dispersing quality of
solvent influenced the percolation concentration , corresponding to
transition between the low conductive and high conductive states: e.g.,
percolation was observed at and for pure COC and 5CB,
respectively. The effects of thermal pre-history on the heating-cooling
hysteretic behavior of electrical conductivity were studied. The mechanism of
dispersion of NTs in COC+5CB mixtures is discussed. Utilization of the mixtures
of "good" and "bad" solvents allowed fine regulation of the dispersion,
stability and electrical conductivity of LC+NTs composites. The mixtures of COC
and 5CB were found to be promising for application as functional media with
controllable useful chiral and electrophysical properties.Comment: 10 pages, 9 figure
Results of experimental investigations of a flexible active harrow with loosening teeth
ArticleSoil tillage processes significantly affect the growth of cultivated plants; therefore,
improvement of various designs and combinations of ploughs is still an actual practical and
scientific task. This paper presents investigations of the design of a soil tillage machine consisting
of three plough bodies equipped from the lateral side with a module with a flexible active harrow
driven by a support wheel. The technological process of tillage by this machine is carried out in
such a way that the module of the flexible active harrow is installed at a certain depth of soil
tillage. The purpose of this work is an experimental comparative investigation of the quality
indicators of the work of a design of the soil tillage working body with a flexible active harrow
having loosening teeth. In the process of comparative experimental investigations of the operation
of ploughs with a standard flexible harrow and an experimental active harrow having loosening
teeth, the soil lumpiness (characterising the quality of crumbling) and water permeability of the
obtained soil structure were estimated. An experimental model of this working tool was tested
under the production conditions, and it showed advantages of loosening and crumpling the soil
compared to the conventional harrows. This can be explained by the fact that the harrow tines,
freely mounted on the axes of its links, ensure their oscillatory movements when moving in two
different planes, thereby creating conditions for more intense soil disintegration
Research of the movement of agricultural aggregates using the methods of the movement stability theory
ArticleThe theory of the movement stability is of crucial practical importance for mobile
agricultural machines and machine aggregates, since it determines how qualitative and stable
their performance is in a particular technological process. It is especially urgent To ensure stable
movement for operation at high speeds of contemporary agricultural aggregates. The aim of this
investigation is detailed examination of criteria for the stability assessment of a mechanical
system used in agriculture, enabling their wide application in order to study the performance of
the system in the case when it is affected by random forces that were not taken into account in
the original model. The considered calculation methods and examples of their application make
it possible to evaluate the performance of complex dynamic systems without numerical solution
of complicated differential equations of the movement in the presence of external disturbances.
The considered example of the stability determination of the movement of a trailed cultivator
showed that this research method can be successfully used for practical purposes. Besides, a
differential equation of disturbed movement has been composed for an actually symmetrical
trailed agricultural machine with a particular mass, which moves at a constant forward speed
under the impact of summary resistance force running along the symmetry axis of the cultivator
and is applied at its centre of gravity. Reduced to normal Cauchy form, this equation was solved
on the PC, which made it possible to determine immediately the conditions for stable movement
of the trailed cultivator
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