Gut microbiota of patients with Parkinson’s disease and healthy volunteers was analyzed by the method of high throughput 16S rRNA sequencing of bacterial genomes. In patients with Parkinson’s ...diseases, changes in the content of 9 genera and 15 species of microorganisms were revealed: reduced content of
Dorea
,
Bacteroides
,
Prevotella
,
Faecalibacterium
,
Bacteroides massiliensis
,
Stoquefichus massiliensis
,
Bacteroides coprocola
,
Blautia glucerasea
,
Dorea longicatena
,
Bacteroides dorei
,
Bacteroides plebeus
,
Prevotella copri
,
Coprococcus eutactus
, and
Ruminococcus callidus
, and increased content of
Christensenella
,
Catabacter
,
Lactobacillus
,
Oscillospira
,
Bifidobacterium
,
Christensenella minuta
,
Catabacter hongkongensis
,
Lactobacillus mucosae
,
Ruminococcus bromii
, and
Papillibacter cinnamivorans
. This microbiological pattern of gut microflora can trigger local inflammation followed by aggregation of α-synuclein and generation of Lewy bodies.
Water is characterized by large molecular electric dipole moments and strong interactions between molecules; however, hydrogen bonds screen the dipole-dipole coupling and suppress the ferroelectric ...order. The situation changes drastically when water is confined: in this case ordering of the molecular dipoles has been predicted, but never unambiguously detected experimentally. In the present study we place separate H
O molecules in the structural channels of a beryl single crystal so that they are located far enough to prevent hydrogen bonding, but close enough to keep the dipole-dipole interaction, resulting in incipient ferroelectricity in the water molecular subsystem. We observe a ferroelectric soft mode that causes Curie-Weiss behaviour of the static permittivity, which saturates below 10 K due to quantum fluctuations. The ferroelectricity of water molecules may play a key role in the functioning of biological systems and find applications in fuel and memory cells, light emitters and other nanoscale electronic devices.
The purpose of the work is to analyze long-term radiocesium wash-off from the catchments contaminated due to the Chernobyl accident in 1986 and Fukushima Dai-ichi NPP (FDNPP) accident in 2011. A ...semiempirical diffusional model for radionuclide wash-off is proposed enabling estimation of
137
Cs dissolved and particulate wash-off coefficients for Chernobyl and Fukushima contaminated catchments, explaining the differences in these parameters and predicting their long-term trend. The model is based on the premise that the erosion of catchment topsoil is the source of sediments in the rivers, and the radionuclide concentration in the topsoil can be described by a simple diffusion equation. The normalized coefficients of particulate
137
Cs wash-off for the Fukushima contaminated catchments are slightly lower than those for Chernobyl. The normalized coefficients of the dissolved
137
Cs wash-off from Fukushima catchments are at least an order of magnitude lower those for Chernobyl, mainly due to an order of magnitude difference in the
137
Cs distribution coefficients for Fukushima and Chernobyl rivers. The proposed semiempirical diffusional model for radionuclide wash-off satisfactorily describes the temporal trends in the variations of the
137
Cs wash-off coefficients, both in the Chernobyl and Fukushima, and can be used for predicting
137
Cs wash-off after a nuclear accident.
In this paper, we present the resistance measurements of the amorphous ferromagnetic Co-rich microwires (metallic nucleus diameters 15–30 μm) during Joule heating by direct current. The heating ...currents were provided by a programming power supply, which allowed setting up a different heating and cooling regimes. The Wheatstone bridge circuit was used for continuous resistance monitoring during the heating process. We observed the dependences of the microwire resistance versus the time and the applied power of heating for the samples having common composition Co69Fe4Cr4Si12B11 and different diameters. It was shown that the irreversible changes of the microwire resistance were occurred during heat treatment. The microwires have gone through a crystallization phase under linear varying power in the range between 0 and 4.5 W and their relative resistance reduced by up to 10% relative to the initial values. The one-time annealing run increases the relative resistance of the microwires samples from 0.1% to 1% at the various values of maximum power. The repeated heating processes result to the reversibility of the resistance values; in that case each value of maximum applied power provides finite rise of the microwire resistance value.
•Joule heating set-up for in-situ resistance measurements of amorphous ferromagnetic microwires has been developed.•Small electrical resistance changes during heating process has been monitored in Co69Fe4Cr4Si12B11 amorphous microwires.•The microwire resistance changes indicate the structural transformations occurring in the material.
Electrical transport mechanisms of 2D carbon nanotube networks are presently under intensive studies. The related experimental data are ambiguous and controversial. We report on terahertz-infrared ...spectra of optical conductivity and dielectric permittivity of thin transparent films composed of pristine and CuCl- or iodine-doped single-walled carbon nanotubes (SWCNTs) measured in the frequency range from 7 to 25 000 cm−1 and at temperatures from 5 to 300 K. Controversially to the existing results, we have not observed a clear signature of the so-called terahertz conductivity peak. Instead, a typical metallic-like frequency- and temperature-dependent behavior of the conductivity and permittivity has been discovered. It was attributed to the high quality interconnected SWCNT network providing the almost free pathways for charge carriers. Applying Drude conductivity model, we have determined the temperature and doping dependences of effective parameters of the carriers in the films: plasma frequency, scattering rate, mobility, mean-free path. The obtained results demonstrate a great potential of the material in the field of electromagnetic applications at frequencies up to few terahertz.
Display omitted
Abstract
In 2018, the Belle II experiment, aimed at detailed studies of B-mesons, started operation at the Super-KEKB electron–positron collider at KEK (Japan). This was preceded by the long and ...quite successful work of the B-factories of previous generations, including the Belle experiment, to which Belle II is a successor. This experiment is unique, having no counterparts or competitors in the world. The spectrum of problems it is aimed at is quite broad: from studies of hadronic states containing heavy quarks to precision measurements and the search for New Physics beyond the Standard Model. This review describes specific features of the Belle II experiment, its ambitious goals and specific tasks, expected results of its work, and hopes related to its successful implementation.
In order to optimize the testosterone model of benign prostatic hyperplasia, we studied the effect of castration and different doses of testosterone on the induction of the proliferative process in ...the prostate of Wistar rats. It was shown that 4-week subcutaneous administration of testosterone propionate in a dose of 20 mg/kg causes pronounced proliferative and hemodynamic disorders in the dorsolateral gland morphologically similar in castrated and non-castrated males. Administration of testosterone in a dose of 3 mg/kg had no significant effect on the dynamics of the pathological process in non-operated rats and normalized the structure of the gland in castrated animals. Morphological study showed that castration of males provides no visible advantages in reproducing the testosterone model of benign prostatic hyperplasia. The proposed non-traumatic modification of the model with a high dose of testosterone has good reproducibility and sensitivity to therapeutic agents, as shown by the example of finasteride.
Dielectric spectra of SrTiO
3
and SrTiO
3
:Mn single crystals have been studied in the frequency range of 10‒3000 cm
–1
and in the temperature range of 5–297 K using time-domain terahertz ...spectroscopy and Fourier-transform infrared spectroscopy. A comparative analysis of the experimental results made it possible to detect a significant broadening of the absorption lines corresponding to the Slater and Last phonon modes, while the parameters of the Axe mode when replacing Ti with Mn (2 at %) stay invariant. This effect is associated with an enhance in structural disorder in the cation subsystem (B-sublattice) of the SrTiO
3
crystal. It has been established that doping with Mn ions reduces the antiferrodistortive phase transition temperature by about 20 K, but hardly affects the character of the temperature dependence of the parameters of a ferroelectric soft mode at temperatures of about 60–297 K. It has been found that an additional excitation with the frequency below the frequency of the ferroelectric soft mode should be taken into account for an appropriate model description of the dispersion of the permittivity of SrTiO
3
:Mn in the terahertz frequency range. The results obtained in this work indicate that dielectric relaxation in the SrTiO
3
:Mn crystal is due to thermally activated hops of Mn atoms between displaced (noncentral) crystallographic sites; i.e., the mechanism of radiofrequency relaxation in SrTiO
3
:Mn is hopping rather than polaronic, which is also actively discussed in the literature.
The results of measurements of the exclusive cross section for the
e
+
e
−
→
D
(*)±
D
*∓
process near the open charm threshold with initial-state radiation are presented. The analysis is based on the ...experimental data collected with the Belle detector at energies
s
equal to ϒ(4S), ϒ(5S) production energies, and energies of the nearby continuum corresponding to an integrated luminosity of 951 fb
−1
. The accuracy of the measurements of the cross sections is twice higher in comparison with the previous results of the Belle collaboration. An angular analysis is performed for the final state
D
*
+
D
*
−
for the first time with the result that the cross section is decomposed into three components corresponding to the possible combinations of
D
*-meson polarizations in the final state.
Spatial distributions of activity density (kBq/m2) and activity concentration (Bq/kg) are studied on sites with non-cultivated soils. Fitting datasets with lognormal, Weibull and normal distributions ...with sampling size n ≥ 60 showed that radionuclide deposition (90Sr, 137Cs, 238Pu, 239+240Pu, 241Am) due to Chernobyl fallout no more than in 10% of cases are described by Weibull distribution, and in the rest of the cases – by lognormal distribution. However asymptotics of “righthand tail” of empirical (sample) distribution quite often differs from the right-hand tail asymptotics of lognormal distribution. Thereby lognormal distribution is only an approximate statistical model of radionuclides' spatial pattern.
Estimates of site surface area with “hot spots” are considered. Also distributions of 137Cs and 134Cs activity concentration on the territory contaminated by Fukushima fallout are reviewed. Characteristics of activity concentration for Fukushima and Chernobyl fallouts are collated. The results obtained make it possible to suggest that in both cases spatial contaminations of soil are described by approximately the same statistical models.
•90Sr, 137Cs, 238Pu, 239Pu, 241Am datasets are described by lognormal distribution.•The right-hand tail of empirical distribution differs from lognormal distribution.•An assumption of lognormality is an idealization.
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