Synthesis of cationic plastoquinone derivatives (SkQs) containing positively charged phosphonium or rhodamine moieties connected to plastoquinone by decane or pentane linkers is described. It is ...shown that SkQs (i) easily penetrate through planar, mitochondrial, and outer cell membranes, (ii) at low (nanomolar) concentrations, posses strong antioxidant activity in aqueous solution, BLM, lipid micelles, liposomes, isolated mitochondria, and cells, (iii) at higher (micromolar) concentrations, show pronounced prooxidant activity, the “window” between anti- and prooxidant concentrations being very much larger than for MitoQ, a cationic ubiquinone derivative showing very much lower antioxidant activity and higher prooxidant activity, (iv) are reduced by the respiratory chain to SkQH₂, the rate of oxidation of SkQH₂ being lower than the rate of SkQ reduction, and (v) prevent oxidation of mitochondrial cardiolipin by OH·. In HeLa cells and human fibroblasts, SkQs operate as powerful inhibitors of the ROS-induced apoptosis and necrosis. For the two most active SkQs, namely SkQ1 and SkQR1, C ₁/₂ values for inhibition of the H₂O₂-induced apoptosis in fibroblasts appear to be as low as 1·10⁻¹¹ and 8·10⁻¹³ M, respectively. SkQR1, a fluorescent representative of the SkQ family, specifically stains a single type of organelles in the living cell, i.e. energized mitochondria. Such specificity is explained by the fact that it is the mitochondrial matrix that is the only negatively-charged compartment inside the cell. Assuming that the Δψ values on the outer cell and inner mitochondrial membranes are about 60 and 180 mV, respectively, and taking into account distribution coefficient of SkQ1 between lipid and water (about 13,000: 1), the SkQ1 concentration in the inner leaflet of the inner mitochondrial membrane should be 1.3·10⁸ times higher than in the extracellular space. This explains the very high efficiency of such compounds in experiments on cell cultures. It is concluded that SkQs are rechargeable, mitochondria-targeted antioxidants of very high efficiency and specificity. Therefore, they might be used to effectively prevent ROS-induced oxidation of lipids and proteins in the inner mitochondrial membrane in vivo.
The thermodynamic properties of the liquid and solid Ag-In-Sn alloys were determined, using an electromotive force (EMF) method with an eutectic mixture of (KCl + LiCl) as a liquid electrolyte. The ...measurements were performed over the temperature range from 635 K to 856 K along the cross-sections Ag0.5Sn0.5-In, Ag0.5In0.5-Sn and In0.5Sn0.5-Ag. The partial thermodynamic functions of indium and liquidus temperatures of the investigated alloys were found from the obtained EMF values. The integral thermodynamic properties of alloys at 750 K along the Ag0.5Sn0.5-In cross-section were calculated by Gibbs-Duhem integration.
Experimental points E(T) of the Inx(Ag0.5Sn0.5)1-x isopleth; xIn=0.10 (+); 0.20 (□); 0.333(○); 0.40 (△); 0.50 (▽). Display omitted
•The electromotive force method (EMF) with a liquid electrolyte was used to determine the activity of indium in liquid and solid alloys of the Ag-In-Sn system.•The partial thermodynamic functions of indium were calculated from the obtained EMF values.•The Gibbs-Duhem integration was used to calculate the integral thermodynamic properties of alloys at 750 K along the Ag0.5Sn0.5-In cross-section.
Phase equilibria in the Cu-In-Zn system are calculated using a thermodynamic modeling approach. The thermodynamic model parameters for the constituent binaries Cu-In,Cu-Zn and In-Zn are taken from ...earlier assessments. Thermodynamic descriptions of the ternary liquid and copper-based solutions are obtained based on the experimental thermodynamic and phase equilibria data available in literature for the Cu-In-Zn system. The liquidus surface projection, isothermal sections at 373 and 573 K, as well as vertical sections xCu/xIn = 1:2, 1:1, 2:1 and xIn = 0.75, 0.5 are calculated.
Display omitted
•Thermodynamic modeling of the system Cu-In-Zn.•Calculation of five vertical sections and two isothermal sections.•Calculated liquidus surface projection.
Any compact body with regular boundary in ℝ
N
defines a two-valued function on the space of affine hyperplanes: the volumes of the two parts into which these hyperplanes cut the body. This function ...is never algebraic if
N
is even and is very rarely algebraic if
N
is odd: all known bodies defining algebraic volume functions are ellipsoids (and have been essentially found by Archimedes for
N
= 3). We demonstrate a new series of
locally
algebraically integrable bodies with algebraic boundaries in spaces of arbitrary dimensions, that is, of bodies such that the corresponding volume functions coincide with algebraic ones in some open domains of the space of hyperplanes intersecting the body.
An approach to the implementation of the defuzzification procedure in microprocessor systems of fuzzy information processing is proposed. A computationally efficient model of the defuzzification ...operation is considered, based on the use of the concept of the measure of validity of a logical conclusion as a composition of the current values of the reliability of all elements of the conditional part of the rule that proposes this conclusion. The application of the approach provides a significant improvement in the quality of fuzzy approximation with little complexity of algorithmic and hardware-software tools. Examples of the use of this approach in practical problems are given.
Abstract
We prove that there are no bounded domains with smooth boundaries in even-dimensional Euclidean spaces, such that the volumes cut off from them by affine hyperplanes depend algebraically on ...these hyperplanes. For convex ovals in ${{{\mathbb R}}}^2$, this is Lemma XXVIII from Newton's 'Philosophiae naturalis principia mathematica'.
The calculated vertical section of the Cu–In–Pb system at xCu/xPb=1.
•Thermodynamic modeling of the system Cu–In–Pb.•Calculation of four vertical sections and two isothermal sections.•Calculated ...liquidus surface projection.
Phase equilibria in the Cu–In–Pb system are calculated using a thermodynamic modeling approach. The thermodynamic model parameters for the constituent binaries Cu–In, Cu–Pb and In–Pb are taken from earlier assessments. Thermodynamic description of the ternary liquid phase is obtained based on the phase equilibria data available in literature for the xIn=0.75 vertical section of the Cu–In–Pb system. The liquidus surface projection, isothermal sections at 373 and 573K, as well as vertical sections xCu/xPb=1, xIn=0.75, xIn=0.5, and xIn=0.25 are calculated.
We calculate homology groups with certain twisted coefficients of configuration spaces of projective spaces. This completes a calculation of rational homology groups of spaces of odd maps of spheres
...S
m
→
S
M
,
m
<
M
, and of the stable homology of spaces of non-resultant polynomial maps ℝ
m
+1
→ ℝ
M
+1.
Also, we calculate the homology of spaces of ℤ
r
-equivariant maps of odd-dimensional spheres, and discuss further generalizations.
The rational homology group of the order complex of non-even partitions of a finite set is calculated. A twisted version of Goresky–MacPherson approach to similar homology calculations is proposed.
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