1,765 research outputs found
MAST CELLS AS BIOMARKERS OF INFLAMM-AGEING
Most mechanisms of ageing are believed to be more or less associated with inflammation. With age, a unique form of chronic inflammation develops which is termed as âinflamm-ageingâ. The mechanisms of this process are still not fully clear due to the lack of reliable assessment criteria. Immune system is among those involved in accelerating age-related changes in the body. It also directly participates in the process of inflammation. In its pathogenesis, the reaction of mast cells may be of great importance. The role of mast cells in tissue remodeling deserves special attention, since the latter event is among the main features associated with ageing. Hence, the âinflamm-ageingâ is considered a sufficient indicator of ageing, and the mast cells could provide biomarkers of this process. In order to test the proposed hypothesis, the present study was conducted to determine age-related morpho-functional changes in mast cell populations in various organs in rats. Some morpho-functional parameters of mast cells (number, synthetic and functional activity, degree of maturation) in different animal organs were evaluated in male Wistar rats of different ages (4 months and 2 years). We have found the age-dependent changes upon examination of thymus, adrenal glands, and skin, i.e., a decrease in the number of mast cells and their synthetic capacity, along with significantly increased functional activity. In the stomach, small and large intestines, at the constant number of mast cells, we revealed a decrease in their synthetic ability, and increased functional activity. These changes were accompanied by enlargement of blood vessels in the studied organs. Liver is the only organ which did not exhibit any changes in mast cell populations with age. The detected changes in mast cell populations may play an important role in formation of âinflamm-ageingâ events, which accompany the ageing processes, because these cells are an integral component of inflammatory response. The progression of âinflamm-ageingâ leads to accumulation of cytokines and pro-inflammatory mediators in tissues, which, in turn, activate the mast cells. At the same time, increased degranulation of mastocytes may promote the process of âinflamm-ageingâ. The oberved mutual influence of mast cells and âinflamm-ageingâ makes it possible to consider mastocytes as potential candidates for searching the biomarkers in âinflamm-ageingâ. © 2022, RSI
Shape of primary proton spectrum in multi-TeV region from data on vertical muon flux
It is shown, that primary proton spectrum, reconstructed from sea-level and
underground data on muon spectrum with the use of QGSJET 01, QGSJET II, NEXUS
3.97 and SIBYLL 2.1 interaction models, demonstrates not only model-dependent
intensity, but also model-dependent form. For correct reproduction of muon
spectrum shape primary proton flux should have non-constant power index for all
considered models, except SIBYLL 2.1, with break at energies around 10-15 TeV
and value of exponent before break close to that obtained in ATIC-2 experiment.
To validate presence of this break understanding of inclusive spectra behavior
in fragmentation region in p-air collisions should be improved, but we show,
that it is impossible to do on the basis of the existing experimental data on
primary nuclei, atmospheric muon and hadron fluxes.Comment: Submitted to Phys. Rev.
MORTALITY IN EXPERIMENTAL AND NATURAL INFECTION CAUSED BY HIGHLY PATHOGENIC INFLUENZA VIRUS H5N1
In this paper the data for mortality from experimental infections and natural contamination in different species of poultry is presented. Mortality of natural contamination was identified during the epizootic of influenza in the Novosibirsk area in July 2005. We infected domestic geese, ducks and two breeds of chickens with highly pathogenic influenza virus A/goose/Krasnoozerskoye/627/05 (H5N1) for the experiments constructed
Ozone profiles in the high-latitude stratosphere and lower mesosphere measured by the Improved Limb Atmospheric Spectrometer (ILAS)-II: comparison with other satellite sensors and ozonesondes
A solar occultation sensor, the Improved Limb Atmospheric Spectrometer (ILAS)-II, measured 5890 vertical profiles of ozone concentrations in the stratosphere and lower mesosphere and of other species from January to October 2003. The measurement latitude coverage was 54â71°N and 64â88°S, which is similar to the coverage of ILAS (November 1996 to June 1997). One purpose of the ILAS-II measurements was to continue such high-latitude measurements of ozone and its related chemical species in order to help accurately determine their trends. The present paper assesses the quality of ozone data in the version 1.4 retrieval algorithm, through comparisons with results obtained from comprehensive ozonesonde measurements and four satellite-borne solar occultation sensors. In the Northern Hemisphere (NH), the ILAS-II ozone data agree with the other data within ±10% (in terms of the absolute difference divided by its mean value) at altitudes between 11 and 40 km, with the median coincident ILAS-II profiles being systematically up to 10% higher below 20 km and up to 10% lower between 21 and 40 km after screening possible suspicious retrievals. Above 41 km, the negative bias between the NH ILAS-II ozone data and the other data increases with increasing altitude and reaches 30% at 61â65 km. In the Southern Hemisphere, the ILAS-II ozone data agree with the other data within ±10% in the altitude range of 11â60 km, with the median coincident profiles being on average up to 10% higher below 20 km and up to 10% lower above 20 km. Considering the accuracy of the other data used for this comparative study, the version 1.4 ozone data are suitably used for quantitative analyses in the high-latitude stratosphere in both the Northern and Southern Hemisphere and in the lower mesosphere in the Southern Hemisphere
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Hybrid gas-metal co-implantation with a modified vacuum arc ion source
Energetic beams of mixed metal and gaseous ion species can be generated with a vacuum arc ion source by adding gas to the arc discharge region. This could be an important tool for ion implantation research by providing a method for forming buried layers of mixed composition such as e.g. metal oxides and nitrides. In work to date, we have formed a number of mixed metal-gas ion beams including Ti+N, Pt+N, Al+O, and Zr+O. The particle current fractions of the metal-gas ion components in the beam ranged from 100% metallic to about 80% gaseous, depending on operational parameters. We have used this new variant of the vacuum arc ion source to carry out some exploratory studies of the effect of Al+O and Zr+O co-implantation on tribology of stainless steel. Here we describe the ion source modifications, species and charge state of the hybrid beams produced, and results of preliminary studies of surface modification of stainless steel by co-implantation of mixed Al/O or Zr/O ion beams. 5 figs, 21 refs
Student research in medicine and their contribution to world science
In May 2021, the conference "Fundamental Medicine. History and Prospects, "at which first-year students of the Faculty of Medicine and Prevention made presentations on the history of the formation and development of physiological sciences in the Urals, outlining the biography of the founder of the physiological school at SGMI-UgMU, academician Vasily Vasilyevich Parin, and with a historical analysis of the role of student science in the development of medicine. This article presents brief points of the last reportĐ ĐŒĐ°Đ” 2021 Đł. ĐČ ĐŒŃзДД ĐžŃŃĐŸŃОО ĐŒĐ”ĐŽĐžŃĐžĐœŃ ĐŁĐĐĐŁ ŃĐŸŃŃĐŸŃлаŃŃ ĐșĐŸĐœŃĐ”ŃĐ”ĐœŃĐžŃ Â«Đ€ŃĐœĐŽĐ°ĐŒĐ”ĐœŃĐ°Đ»ŃĐœĐ°Ń ĐŒĐ”ĐŽĐžŃĐžĐœĐ°. ĐŃŃĐŸŃĐžŃ Đž пДŃŃпДĐșŃĐžĐČŃ», ĐœĐ° ĐșĐŸŃĐŸŃĐŸĐč ŃŃŃĐŽĐ”ĐœŃŃ ĐżĐ”ŃĐČĐŸĐłĐŸ ĐșŃŃŃĐ° лДŃĐ”Đ±ĐœĐŸĐłĐŸ-ĐżŃĐŸŃОлаĐșŃĐžŃĐ”ŃĐșĐŸĐłĐŸ ŃĐ°ĐșŃĐ»ŃŃĐ”ŃĐ° ĐČŃŃŃŃпОлО Ń ĐŽĐŸĐșĐ»Đ°ĐŽĐ°ĐŒĐž ĐżĐŸ ĐžŃŃĐŸŃОО ŃŃĐ°ĐœĐŸĐČĐ»Đ”ĐœĐžŃ Đž ŃĐ°Đ·ĐČĐžŃĐžŃ ŃĐžĐ·ĐžĐŸĐ»ĐŸĐłĐžŃĐ”ŃĐșĐžŃ
ĐœĐ°ŃĐș ĐœĐ° ĐŁŃалД Ń ĐžĐ·Đ»ĐŸĐ¶Đ”ĐœĐžĐ”ĐŒ Đ±ĐžĐŸĐłŃĐ°ŃОО ĐŸŃĐœĐŸĐČĐ°ŃĐ”Đ»Ń ŃĐžĐ·ĐžĐŸĐ»ĐŸĐłĐžŃĐ”ŃĐșĐŸĐč ŃĐșĐŸĐ»Ń ĐČ ĐĄĐĐĐ-ĐŁĐĐĐŁ Đ°ĐșĐ°ĐŽĐ”ĐŒĐžĐșĐ° ĐĐ°ŃĐžĐ»ĐžŃ ĐĐ°ŃОлŃĐ”ĐČĐžŃĐ° ĐĐ°ŃĐžĐœĐ° Đž c ĐžŃŃĐŸŃĐžŃĐ”ŃĐșĐžĐŒ Đ°ĐœĐ°Đ»ĐžĐ·ĐŸĐŒ ŃĐŸĐ»Đž ŃŃŃĐŽĐ”ĐœŃĐ”ŃĐșĐŸĐč ĐœĐ°ŃĐșĐž ĐČ ŃĐ°Đ·ĐČĐžŃОО ĐŒĐ”ĐŽĐžŃĐžĐœŃ. ĐĐ°ĐœĐœĐ°Ń ŃŃĐ°ŃŃŃ ĐżŃДЎŃŃĐ°ĐČĐ»ŃĐ”Ń ĐșŃĐ°ŃĐșОД ŃДзОŃŃ ĐżĐŸŃĐ»Đ”ĐŽĐœĐ”ĐłĐŸ ĐŽĐŸĐșлаЎ
On inconsistency of experimental data on primary nuclei spectra with sea level muon intensity measurements
For the first time a complete set of the most recent direct data on primary
cosmic ray spectra is used as input into calculations of muon flux at sea level
in wide energy range GeV. Computations have been performed
with the CORSIKA/QGSJET and CORSIKA/VENUS codes. The comparison of the obtained
muon intensity with the data of muon experiments shows, that measurements of
primary nuclei spectra conform to sea level muon data only up to several tens
of GeV and result in essential deficit of muons at higher energies. As it
follows from our examination, uncertainties in muon flux measurements and in
the description of nuclear cascades development are not suitable to explain
this contradiction, and the only remaining factor, leading to this situation,
is underestimation of primary light nuclei fluxes. We have considered
systematic effects, that may distort the results of the primary cosmic ray
measurements with the application of the emulsion chambers. We suggest, that
re-examination of these measurements is required with the employment of
different hadronic interaction models. Also, in our point of view, it is
necessary to perform estimates of possible influence of the fact, that sizable
fraction of events, identified as protons, actually are antiprotons. Study of
these cosmic ray component begins to attract much attention, but today nothing
definite is known for the energies GeV. In any case, to realize whether
the mentioned, or some other reasons are the sources of disagreement of the
data on primaries with the data on muons, the indicated effects should be
thoroughly analyzed
Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors
We report on the first measurement of 39Ar in argon from underground natural
gas reservoirs. The gas stored in the US National Helium Reserve was found to
contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be
<=4x10-17 (84% C.L.), less than 5% the value in atmospheric argon
(39Ar/Ar=8x10-16). The total quantity of argon currently stored in the National
Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most
important backgrounds in argon detectors for WIMP dark matter searches. The
findings reported demonstrate the possibility of constructing large multi-ton
argon detectors with low radioactivity suitable for WIMP dark matter searches.Comment: 6 pages, 2 figures, 2 table
Measurement of CP Asymmetries and Branching Fractions in Charmless Two-Body B-Meson Decays to Pions and Kaons
We present improved measurements of CP-violation parameters in the decays
, , and , and of
the branching fractions for and . The
results are obtained with the full data set collected at the
resonance by the BABAR experiment at the PEP-II asymmetric-energy factory
at the SLAC National Accelerator Laboratory, corresponding to
million pairs. We find the CP-violation parameter values and
branching fractions where in each case, the first uncertainties are statistical
and the second are systematic. We observe CP violation with a significance of
6.7 standard deviations for and 6.1 standard deviations for
, including systematic uncertainties. Constraints on the
Unitarity Triangle angle are determined from the isospin relations
among the rates and asymmetries. Considering only the solution
preferred by the Standard Model, we find to be in the range
at the 68% confidence level.Comment: 18 pages, 11 postscript figures, submitted to Phys. Rev.
Measurement of Branching Fractions and Rate Asymmetries in the Rare Decays B -> K(*) l+ l-
In a sample of 471 million BB events collected with the BABAR detector at the
PEP-II e+e- collider we study the rare decays B -> K(*) l+ l-, where l+ l- is
either e+e- or mu+mu-. We report results on partial branching fractions and
isospin asymmetries in seven bins of di-lepton mass-squared. We further present
CP and lepton-flavor asymmetries for di-lepton masses below and above the J/psi
resonance. We find no evidence for CP or lepton-flavor violation. The partial
branching fractions and isospin asymmetries are consistent with the Standard
Model predictions and with results from other experiments.Comment: 16 pages, 14 figures, accepted by Phys. Rev.
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