Dihydroquercetin (DHQ) is a bioflavonoid with high antioxidant, capillary-protective, and anti-inflammatory activity. DHQ has previously been used for treating Middle East respiratory syndrome ...coronavirus (MERS-CoV) infection and is currently considered a potential regulator of oxidative stress as part of COVID-19 multipurpose therapy. DHQ has a high safety profile but low bioavailability that limits its use. Innovative techniques (liposomization, crystal engineering, etc.) can be used to increase its bioavailability.
We consider a model elliptic pseudodifferential equation and the simplest boundary value problems in a quadrant in a Sobolev–Slobodetsky space of different orders of smoothness in different ...variables. In the case of a special representation of the symbol, we describe a general solution of the equation and consider the simplest boundary value problem with the Dirichlet and Neumann conditions on the sides of the quadrant. This boundary value problem is reduced to a system of integral equations, which, under additional assumptions about the structure of the symbol, can also be reduced to a system of first-order difference equations.
•D plasma ions impact on BMG leads to D absorption and modification of some properties.•At D ion energy< 120 eV, the amount of D absorbed increases linearly with ion fluence.•At D ion energy> 450 eV, ...the sputtering process dominates.•Plane BMG samples exposed in D plasma are bent due to D trapping in near-surface layer.
Samples of two kinds of bulk metallic glasses (BMG) with different compositions, Zr48Cu36Al8Ag8 and Zr57Cu15.4Al10Ni12.6Nb5, were polished to mirror-like quality and, after measuring the initial reflectance at normal light incidence, were subjected to impact of ions of deuterium or argon plasma with fixed energy. The main attention was paid to phenomenon on deuterium absorption that reveals as the weight gain after every exposure of the samples in deuterium plasma. For a fixed ion energy (in the range<100 eV), the amount of absorbed deuterium increased linearly with increasing of the ion fluence. Bending of the samples was observed when one side of sample was bombarded by deuterium plasma ions. At that, the radius of curvature of samples was decreasing with increasing the amount of trapped deuterium in such a way that its curvature was increasing proportionally to the amount of trapped deuterium. This is an evidence of near-surface distribution of the trapped deuterium. The results demonstrate that D ions within a fluence of ∼2·1025 ions/m2 are initially accumulated in a thin near-surface layer of the samples. Further, they are noted effects of stress relaxation and of deuterium redistribution.
The processes involved in the solution combustion synthesis of α-Al2O3 using urea as an organic fuel were investigated. The data describing the influence of the relative urea content on the ...characteristic features of the combustion process, the crystalline structure and the morphology of the aluminium oxide are presented herein. Our data demonstrate that the combustion of stable aluminium nitrate and urea complexes leads to the formation of α-alumina at temperatures of approximately 600–800°C. Our results, obtained using differential thermal analysis and IR spectroscopy methods, reveal that the low-temperature formation of α-alumina is associated with the thermal decomposition of an α-AlO(OH) intermediate, which was crystallised in the crystal structure of the diaspore.
New multiarm stars have been synthesized based on polylithium derivatives of high-generation carbosilane dendrimers. In the synthesis of multiarm stars based on the eighth-generation dendrimer, ...steric hindrances were observed even during the synthesis of a polylithium initiator. Subsequently, this led to chain transfer reactions between growing arms, as well as other side effects. As a result, dense nanogel formations with a higher tendency of ordering than in classical objects of this type were isolated from the reaction mixture. The study of the rheology of multiarm stars based on sixth-generation dendrimers made it possible to determine the activation energies of viscous flow in these objects, which makes it possible to consider them as objects with a macromolecular nature and a reptation flow mechanism.
New cross-linked polymers with different morphology based on cyclotriphosphazene and polysiloxane precursors were obtained by the thiol-ene radical addition. A series of samples such as aerogels with ...various density, a xerogel, a monolith and a film were prepared and their physico-mechanical properties were studied. Phosphazene-containing polymeric aerogels were prepared directly in supercritical carbon dioxide (scCO2) media. The morphology of the samples was investigated by scanning electron microscopy (SEM). The average particle size in the aerogels was in the range of 2–15 μm. The mechanical properties of all the samples were studied by the compression test. It was shown that the Young modulus of the monolith (95 MPa) was 7 times larger than that of the xerogel (14 MPa). The aerogels are porous elastic polymers with the Young modulus of 0.032 and 0.257 MPa, correspondingly. The thermal stability of the samples was evaluated by thermal gravimetric analysis (TGA). Weight loss was observed in the range of 255–298 °C in air and 251–295 °C in argon for all the samples. Aerogel samples have a greater water contact angle (130° for A1 and 136° for A2) than xerogel (122°), monolith (121°) and film samples (84°), which can be explained by the lotus effect.
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•Cross-linked polymers based on functional cyclotriphosphazene and polysiloxane were obtained.•Polymers were prepared by the thiol-ene radical addition.•Aerogels with various density, xerogel, monolith and film were prepared.•Properties of all samples were investigated.
—The characteristics of MWIRs focal plane aeeays made in the form of a hybrid chip based on a planar
n
+
–p-
HgCdTe focal matrix with 2048 × 2048 elements and a silicon multiplexer are considered. ...The temperature dependence of the reverse current of elements in the 125–300 K range had a characteristic Arrhenius dependence with an activation energy close to the band gap of the semiconductor and was limited by the diffusion component of the current. At a lower temperature, the current was limited by the generation of carriers with the participation of a deep level near the middle of the forbidden band. The histogram of the detectability of the elements of the matrix had the form of a symmetric curve with a maximum and an average value ≈ 1.3 × 10
12
cm Hz
1/2
/W.
The spectrumω(G) of a finite group G is the set of element orders of G. Finite groups G and H are isospectral if their spectra coincide. Suppose that L is a simple classical group of sufficiently ...large dimension (the lower bound varies for different types of groups but is at most 62) defined over a finite field of characteristic p. It is proved that a finite group G isospectral to L cannot have a nonabelian composition factor which is a group of Lie type defined over a field of characteristic distinct from p. Together with a series of previous results this implies that every finite group G isospectral to L is ‘close’ to L. Namely, if L is a linear or unitary group, then L⩽G⩽AutL, in particular, there are only finitely many such groups G for given L. If L is a symplectic or orthogonal group, then G has a unique nonabelian composition factor S and, for given L, there are at most 3 variants for S (including S≃L).
The subject matter of the reported work refers to studying the interactions followed by the excited-state generation, which are chemical models of oxidative processes leading to a weak light emission ...emerging from living cells, and to explore the possibilities of using them as tools for evaluating the activity of oxygen-metabolism modulators, most prominently, natural bioantioxidants of biomedical value in particular. Methodologically, major attention is paid to analyzing the shapes of the time profiles of the light emission derived from a model sensory system in the presence of lipid samples of vegetable and animal (fish) origin rich in bioantioxidants. As a result, a modified reaction mechanism involving 12 elementary steps is proposed to rationalize the light-emission kinetics in the presence of natural bioantioxidants. We conclude that free radicals formed from bioantioxidants and their dimerization products contribute significantly to the general antiradical activity of lipid samples, which should be taken into account in developing efficient bioantioxidant assays for biomedical applications and while establishing the mechanisms of bioantioxidant effects on metabolic processes in vivo.
Techniques of synthesis of RE diborides (RB2) are developed (R=Tb, Dy, Ho, Er, Lu). Temperature dependence of magnetisation, a heat capacity, a lattice parameters of diborides in the range of 2–300K ...are measured. According to joint calorimetric and X-ray research the analysis of a phonon component of a heat capacity and thermal expansion of RE-diborides is carried out by Debye-Einstein's models, the parameters of the model are determined.
The change of magnetisation of the ferromagnetic RB2 compounds with growth of temperature caused by violation of ordering in the system of the atomic magnetic moments is compared with the change of entropy of a magnetic subsystem calculated from calorimetric data. Analytical expansion for calculation of a magnetic component of a heat capacity by RB2 magnetisation data at the temperatures of 2–300K is obtained.
•1 Techniques of synthesis of RE diborides (RB2) are developed (R=Tb, Dy, Ho, Er, Lu).•2 Temperature dependence of magnetisation of diborides at 2–300K is determined.•3 Calculation method of RB2 magnetic heat capacity from magnetic data is obtained.
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