3,695 research outputs found
Restoration of physical performance capacity of athletes after prolonged restriction of their motor activity
The effects of different regimens of treatment following prolonged hypokinesia were studied in order to determine the most effective program. The types of programs considered were passive means, consisting of physical therapy; active means, consisting of athletic training; and a combined program. In the first stage of the experiment, the effects of a 10 day period of hypokinesia were studied. It was determined that the restoration programs must address the problems of: (1) increasing defense function and general tone of the body; (2) restore orthostatic stability; and (3) increase general endurance. In later stages, groups of athletes and nonathletes underwent 30 day periods of hypokinesia. Restoration was carefully monitored for groups treated with the various regimens. It was determined that the most effective treatment was a comprehensive program of passive and active therapy
Single-electron transistor effect in a two-terminal structure
A peculiarity of the single-electron transistor effect makes it possible to
observe this effect even in structures lacking a gate electrode altogether. The
proposed method can be useful for experimental study of charging effects in
structures with an extremely small central island confined between tunnel
barriers like a nanometer-sized quantum dot or a macromolecule probed with a
tunneling microscope), where it is impossible to provide a gate electrode for
control of the tunnel current.Comment: 5 pages, 2 figure
Graphite under uniaxial compression along the c axis: A parameter to relate out-of-plane strain to in-plane phonon frequency
Stacking graphene sheets forms graphite. Two in-plane vibrational modes of
graphite, E1u and E2g(2), are derived from graphene E2g mode, the shifts of
which under compression are all considered as results of in-plane bond
shortening. Values of Gruneisen parameter have been reported to quantify such
relation. However, the reason why the shift rates of these three modes with
pressure differ is unclear. In this work, we introduce a new parameter to
quantify the contribution of out-of-plane strain to the in-plane vibrational
frequencies, suggesting that the compression of \pi-electrons plays a
non-negligible part in both graphite and graphene under high pressure.Comment: 8 pages, 5 figures, 1 tabl
Shuttle Mechanism for Charge Transfer in Coulomb Blockade Nanostructures
Room-temperature Coulomb blockade of charge transport through composite
nanostructures containing organic inter-links has recently been observed. A
pronounced charging effect in combination with the softness of the molecular
links implies that charge transfer gives rise to a significant deformation of
these structures. For a simple model system containing one nanoscale metallic
cluster connected by molecular links to two bulk metallic electrodes we show
that self-excitation of periodic cluster oscillations in conjunction with
sequential processes of cluster charging and decharging appears for a
sufficiently large bias voltage. This new `electron shuttle' mechanism of
discrete charge transfer gives rise to a current through the nanostructure,
which is proportional to the cluster vibration frequency.Comment: 4 pages, 4 figure
Potentiating interaction of ethoxydol and rosuvastatin in an experimental model of Langendorf-isolated rat heart total ischemia-reperfusion
The study of cardioprotective activity showed that in vitro ethoxydol at a dose of 3.8 × 10-4 g/l can significantly improve the morphofunctional state of cardiomyocytes, which is manifested in an increase in the proportion of postischemic cardiac resumption, reduction of ischemic contracture, and recovery of contractility during the reperfusion perio
Use of high throughput sequencing to observe genome dynamics at a single cell level
With the development of high throughput sequencing technology, it becomes
possible to directly analyze mutation distribution in a genome-wide fashion,
dissociating mutation rate measurements from the traditional underlying
assumptions. Here, we sequenced several genomes of Escherichia coli from
colonies obtained after chemical mutagenesis and observed a strikingly
nonrandom distribution of the induced mutations. These include long stretches
of exclusively G to A or C to T transitions along the genome and orders of
magnitude intra- and inter-genomic differences in mutation density. Whereas
most of these observations can be explained by the known features of enzymatic
processes, the others could reflect stochasticity in the molecular processes at
the single-cell level. Our results demonstrate how analysis of the molecular
records left in the genomes of the descendants of an individual mutagenized
cell allows for genome-scale observations of fixation and segregation of
mutations, as well as recombination events, in the single genome of their
progenitor.Comment: 22 pages, 9 figures (including 5 supplementary), one tabl
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