55 research outputs found
ACTION OF 1-VINYL-1,2,4-TRIAZOLE COPOLYMER WITH N-VINYLPIROLIDONE AND METAL-CONTAINING NANOCOMPOSITES ON FUNCTIONAL STATE OF PHAGOCYTIC CELLS
The creation of immuno-biological drugs to increase the effectiveness of specific immunotherapy and immunoprophylaxis is a current trend in medicine to date. Therefore, the search and development of new safe and effective artificial bioorganic complexes (immunomodulators) capable of stimulating individual responses of immune system to reduce infectious morbidity is an important area of research. At the moment, such promising preparations can be considered water-soluble polymeric materials and organo-inorganic polymer nanocomposites with nanoparticles of various metals which possess immunomodulating and bactericidal properties. The study results of the effects of 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone and nanocomposites based on it with gold and silver nanoparticles on acute toxicity and functional state of immunophagocytic cells of experimental animals, as well as the production of IFN-γ, TNF-α and IL-4 by human blood lymphocytes are represented in this article. It was established that the tested preparations do not cause increase in body temperature, decrease in mass and death of animals. It was shown that they also have the multidirectional action on cytokine production by human blood cells in vitro, the ability to increase activity of оxidative stress-related enzymes and antioxidant protection of phagocytes. The data obtained by us allow to explain the need for further investigation of the actions of nanocomposites and copolymer in vitro and in vivo
Assessment of Toxic and Immunoadjuvant Properties of Nanocomposites
Introduction. The current direction in medicine is the creation of immunobiological preparations to increase the effectiveness of specific immunotherapy and immunoprophylaxis, containing immunomodulators in their composition. These natural or synthetic substances can have a regulating effect on the immune system. At present, water-soluble organic-inorganic polymeric materials with nanoparticles of various chemical substances with bactericidal and immunomodulating properties can serve as such promising compounds.The aimof the work is to study the acute toxicity of polymer nanocomposites based on 1-vinil-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles and their effect on the functional state of immune system cells in vitro.Materials and methods.The study of acute toxicity was performed on outbred white mice. The activity of superoxide dismutase and glucose-6-phosphate dehydrogenase were studied in guinea pig peritoneal macrophages. The study of spontaneous and nanocomposite-induced production of pro- (interferon gamma and tumor necrosis factor alpha) and anti-inflammatory (interleukin-4) cytokines by blood cells was carried out using clinical material obtained from volunteers using the ELISA method. Results. It has been established that nanocomposites with silver and gold nanoparticles do not cause the death of white mice, their temperature increase and body weight decrease. The average lethal dose for a nanocomposite with selenium nanoparticles was determined as 1 gram per 1 kilogram of animal mass. It was shown that the tested nanocomposites have a stimulating effect on the production of cytokines by human blood cells in vitro. It was established that a nanocomposite with selenium nanoparticles increases the activity of superoxide dismutase and glucose-6-phosphate dehydrogenase. A comparative analysis of their actions with the actions of commercial preparations of biological origin, with immunomodulatory properties.Conclusion. The data obtained allow us to substantiate the need for further research on the effects of nanocomposites based on 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles on the macroorganism in both in vitro and in vivo conditions
Exact solution of the geometrically frustrated spin-1/2 Ising-Heisenberg model on the triangulated Kagome (triangles-in-triangles) lattice
The geometric frustration of the spin-1/2 Ising-Heisenberg model on the
triangulated Kagome (triangles-in-triangles) lattice is investigated within the
framework of an exact analytical method based on the generalized star-triangle
mapping transformation. Ground-state and finite-temperature phase diagrams are
obtained along with other exact results for the partition function, Helmholtz
free energy, internal energy, entropy, and specific heat, by establishing a
precise mapping relationship to the corresponding spin-1/2 Ising model on the
Kagome lattice. It is shown that the residual entropy of the disordered spin
liquid phase is for the quantum Ising-Heisenberg model significantly lower than
for its semi-classical Ising limit (S_0/N_T k_B = 0.2806 and 0.4752,
respectively), which implies that quantum fluctuations partially lift a
macroscopic degeneracy of the ground-state manifold in the frustrated regime.
The investigated model system has an obvious relevance to a series of polymeric
coordination compounds Cu_9X_2(cpa)_6 (X=F, Cl, Br and cpa=carboxypentonic
acid) for which we made a theoretical prediction about the temperature
dependence of zero-field specific heat.Comment: 13 pages, 7 figures, submitted to Phys. Rev.
BIOLOGICAL EFFECTS OF THE NEW SILVER-CONTAINING POLYMER NANOCOMPOSITE
In the materials there are presented, results of the synthesis and biological testing of the new nanocomposite which, contains silver nanoparticles incapsulated. in the synthetic polymer poly-1-vinyl-1,2,4-triazole. The synthesis method, of silvercontaining polymere nanocomposite is shown. With the use of modern equipment evidence of the nanocomposite with the size of 2-10 nm silver production, are substinated. It was revealed, that the new nanocomposite causes slight changes in the tissue structure of experimental animals internal organs and biochemical shift that is characteristic for the compensatory-adaptive reactions development. There are presented, the results of the silver nanoparticles distribution, mainly in the kidney and. liver tissue
Tomography of Ultra-relativistic Nuclei with Polarized Photon-gluon Collisions
A linearly polarized photon can be quantized from the Lorentz-boosted
electromagnetic field of a nucleus traveling at ultra-relativistic speed. When
two relativistic heavy nuclei pass one another at a distance of a few nuclear
radii, the photon from one nucleus may interact through a virtual
quark-antiquark pair with gluons from the other nucleus forming a short-lived
vector meson (e.g. ). In this experiment, the polarization was
utilized in diffractive photoproduction to observe a unique spin interference
pattern in the angular distribution of decays.
The observed interference is a result of an overlap of two wave functions at a
distance an order of magnitude larger than the travel distance
within its lifetime. The strong-interaction nuclear radii were extracted from
these diffractive interactions, and found to be fm () and fm (), larger than the nuclear charge
radii. The observable is demonstrated to be sensitive to the nuclear geometry
and quantum interference of non-identical particles
Observation of Global Spin Alignment of and Vector Mesons in Nuclear Collisions
The strong force, as one of the four fundamental forces at work in the
universe, governs interactions of quarks and gluons, and binds together the
atomic nucleus. Notwithstanding decades of progress since Yukawa first
developed a description of the force between nucleons in terms of meson
exchange, a full understanding of the strong interaction remains a major
challenge in modern science. One remaining difficulty arises from the
non-perturbative nature of the strong force, which leads to the phenomenon of
quark confinement at distance scales on the order of the size of the proton.
Here we show that in relativistic heavy-ion collisions, where quarks and gluons
are set free over an extended volume, two species of produced vector (spin-1)
mesons, namely and , emerge with a surprising pattern of global
spin alignment. In particular, the global spin alignment for is
unexpectedly large, while that for is consistent with zero. The
observed spin-alignment pattern and magnitude for the cannot be
explained by conventional mechanisms, while a model with strong force fields
accommodates the current data. This is the first time that the strong force
field is experimentally supported as a key mechanism that leads to global spin
alignment. We extract a quantity proportional to the intensity of the field of
the strong force. Within the framework of the Standard Model, where the strong
force is typically described in the quark and gluon language of Quantum
Chromodynamics, the field being considered here is an effective proxy
description. This is a qualitatively new class of measurement, which opens a
new avenue for studying the behaviour of strong force fields via their imprint
on spin alignment
Search for the chiral magnetic effect via charge-dependent azimuthal correlations relative to spectator and participant planes in Au+Au collisions at = 200 GeV
The chiral magnetic effect (CME) refers to charge separation along a strong
magnetic field due to imbalanced chirality of quarks in local parity and
charge-parity violating domains in quantum chromodynamics. The experimental
measurement of the charge separation is made difficult by the presence of a
major background from elliptic azimuthal anisotropy. This background and the
CME signal have different sensitivities to the spectator and participant
planes, and could thus be determined by measurements with respect to these
planes. We report such measurements in Au+Au collisions at a nucleon-nucleon
center-of-mass energy of 200 GeV at the Relativistic Heavy-Ion Collider. It is
found that the charge separation, with the flow background removed, is
consistent with zero in peripheral (large impact parameter) collisions. Some
indication of finite CME signals is seen with a significance of 1--3 standard
deviations in mid-central (intermediate impact parameter) collisions.
Significant residual background effects may, however, still be present.Comment: 8 pages, 3 figure
Measurement of electrons from open heavy-flavor hadron decays in Au+Au collisions at GeV with the STAR detector
We report a new measurement of the production of electrons from open
heavy-flavor hadron decays (HFEs) at mid-rapidity ( 0.7) in Au+Au
collisions at GeV. Invariant yields of HFEs are
measured for the transverse momentum range of GeV/ in
various configurations of the collision geometry. The HFE yields in head-on
Au+Au collisions are suppressed by approximately a factor of 2 compared to that
in + collisions scaled by the average number of binary collisions,
indicating strong interactions between heavy quarks and the hot and dense
medium created in heavy-ion collisions. Comparison of these results with models
provides additional tests of theoretical calculations of heavy quark energy
loss in the quark-gluon plasma
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