The response to stress involves the activation of pathways leading either to protection from the stress origin, eventually resulting in development of stress resistance, or activation of the rapid ...death of the organism. Here we hypothesize that mitochondrial reactive oxygen species (mtROS) play a key role in stress-induced programmed death of the organism, which we called "phenoptosis" in 1997. We demonstrate that the synthetic mitochondria-targeted antioxidant SkQ1 (which specifically abolishes mtROS) prevents rapid death of mice caused by four mechanistically very different shocks: (a) bacterial lipopolysaccharide (LPS) shock, (b) shock in response to intravenous mitochondrial injection, (c) cold shock, and (d) toxic shock caused by the penetrating cation C
TPP. Importantly, under all these stresses mortality was associated with a strong elevation of the levels of pro-inflammatory cytokines and administration of SkQ1 was able to switch off the cytokine storms. Since the main effect of SkQ1 is the neutralization of mtROS, this study provides evidence for the role of mtROS in the activation of innate immune responses mediating stress-induced death of the organism. We propose that SkQ1 may be used clinically to support patients in critical conditions, such as septic shock, extensive trauma, cooling, and severe infection by bacteria or viruses.
Search for bound states in
,
, and
systems is performed by employing coupled homogeneous integral Faddeev equations written in terms of
-matrix components. Instead of the traditional partial-wave ...expansion, a direct integration with respect to angular variables is used in these equations, and three-body coupling in the phase space of each of the
–
–
,
–
–
, and
–
–
systems is taken precisely into account within this approach. Two-body
matrices are the only ingredient of the proposed method. In the case of two-body
interaction, they are found by solving the coupled Lippmann–Schwinger integral equations for the
–
–
system in the (
,
) state, the
system in the (
,
) state, the
–
system in the (
,
) state, and the
–
–
system in the (
,
) state. An updated version of the ESC16 microscopic model is used to obtain two-body
,
YY
, and
YN
interactions generating
matrices. Two-body
NN
interaction is reconstructed on the basis of the charge-dependent Bonn model. Direct numerical calculations of the binding energy for the systems being considered clearly indicate that either of the
and
systems has one bound state with binding energies of 4.5 and 5.5 MeV, respectively, and that the
system has two bound states with binding energies of 2.7 and 4.4 MeV.
Plastoquinone, a very effective electron carrier and antioxidant of chloroplasts, was conjugated with decyltriphenylphosphonium to obtain a cation easily penetrating through membranes. This cation, ...called SkQ1, is specifically targeted to mitochondria by electrophoresis in the electric field formed by the mitochondrial respiratory chain. The respiratory chain also regenerates reduced SkQ1H(2) from its oxidized form that appears as a result of the antioxidant activity of SkQ1H(2). SkQ1H(2) prevents oxidation of cardiolipin, a mitochondrial phospholipid that is especially sensitive to attack by reactive oxygen species (ROS). In cell cultures, SkQ1 and its analog plastoquinonyl decylrhodamine 19 (SkQR1) arrest H(2)O(2)-induced apoptosis. When tested in vivo, SkQs (i) prolong the lifespan of fungi, crustaceans, insects, fish, and mice, (ii) suppress appearance of a large number of traits typical for age-related senescence (cataract, retinopathies, achromotrichia, osteoporosis, lordokyphosis, decline of the immune system, myeloid shift of blood cells, activation of apoptosis, induction of β-galactosidase, phosphorylation of H2AX histones, etc.) and (iii) lower tissue damage and save the lives of young animals after treatments resulting in kidney ischemia, rhabdomyolysis, heart attack, arrhythmia, and stroke. We suggest that the SkQs reduce mitochondrial ROS and, as a consequence, inhibit mitochondria-mediated apoptosis, an obligatory step of execution of programs responsible for both senescence and fast "biochemical suicide" of an organism after a severe metabolic crisis.
The coherent photoproduction of
and
on nuclei in the mass-number region of
is studied systematically over the range between the threshold and the laboratory photon energy of
GeV. The amplitude for ...photoproduction on nuclei is constructed on the basis of the impulse approximation with allowance for a number of processes responsible for meson–nucleus final-state interaction. The pion-rescattering processes
and
occurring on spectator nucleons,
and
production followed by
absorption by spectator nucleons, and three-body
–
NN
and
–
NN
interactions are described for the first time within a unified microscopic approach.
Kaon Electroproduction on the Proton Egorov, M. V.; Postnikov, V. I.
Journal of experimental and theoretical physics,
07/2021, Letnik:
133, Številka:
1
Journal Article
Recenzirano
A model of kaon photoproduction in the
p
(
e
,
e
′
K
+
)Λ,
p
(
e
,
e
′
K
+
)Σ
0
, and
p
(
e
,
e
′
K
0
)Σ
+
processes with the square of the momentum transfer
Q
2
up to 2.5 GeV
2
is proposed. The ...photoproduction amplitude includes the
s
-,
t
-, and
u
-channel Born and
s
- and
u
-channel resonance contributions calculated in the tree approximation. The unitarity of the photoproduction amplitude is partially recovered by introducing the momentum dependence of the hadron decay widths of resonances and an additional effective width taking into account the effect of coupling between open channels without strangeness. The specificities of the calculations are allowance for the longitudinal electromagnetic coupling of photons to hadrons and the introduction of strongly
Q
2
-dependent suppression factors for the Born and resonance components of the photoproduction amplitude. This approach provides an accurate description of the existing data on the angular and
Q
2
distributions for the
p
(
e
,
e
′
K
+
)Λ and
p
(
e
,
e
′
K
+
)Σ
0
reactions. This model also correctly reproduces the dependence of the ratio σ(Σ
0
)/σ(Λ) separately for longitudinally and transversely polarized components of the kaon photoproduction cross section in the
p
(
e
,
e
′
K
+
)Λ and
p
(
e
,
e
′
K
+
)Σ
0
processes.
This work is devoted to the study of the distribution of residual plastic strains on outer and inner surface over the length of a cylindrical shell in the process of dynamic deformation generated by ...a longitudinal impact on its end face. As a mathematical model, the Timoschenko's model was used to describe the dynamic deformation of elastic thin shells, modified for the case of plastic deformations using the Bingham's model. As the boundary conditions, we selected a longitudinal impact applied at the end face of the shell with longitudinal strains constant in time. As a method for solving the resulting system of differential equations in partial derivatives of a hyperbolic type, the third-order ray method was implemented. The paper represents options for the numerical calculation of the distribution of residual plastic strains for various thicknesses, as well as the corresponding shell shape after unloading.
Effects of 10-(6′-plastoquinonyl) decyltriphenylphosphonium (SkQ1) and 10-(6′-plastoquinonyl) decylrhod-amine 19 (SkQR1) on rat models of H
2
O
2
- and ischemia-induced heart arrhythmia, heart ...infarction, kidney ischemia, and stroke have been studied
ex vivo
and
in vivo
. In all the models listed, SkQ1 and/or SkQR1 showed pronounced protective effect. Supplementation of food with extremely low SkQ1 amount (down to 0.02 nmol SkQ1/kg per day for 3 weeks) was found to abolish the steady heart arrhythmia caused by perfusion of isolated rat heart with H
2
O
2
or by ischemia/reperfusion. Higher SkQ1 (125–250 nmol/kg per day for 2–3 weeks) was found to decrease the heart infarction region induced by an
in vivo
ischemia/reperfusion and lowered the blood levels of lactate dehydrogenase and creatine kinase increasing as a result of ischemia/reperfusion. In single-kidney rats, ischemia/reperfusion of the kidney was shown to kill the majority of the animals in 2–4 days, whereas one injection of SkQ1 or SkQR1 (1 μmol/kg a day before ischemia) saved lives of almost all treated rats. Effect of SkQR1 was accompanied by decrease in ROS (reactive oxygen species) level in kidney cells as well as by partial or complete normalization of blood creatinine and of some other kidney-controlled parameters. On the other hand, this amount of SkQ1 (a SkQ derivative of lower membrane-penetrating ability than SkQR1) saved the life but failed to normalize ROS and creatinine levels. Such an effect indicates that death under conditions of partial kidney dysfunction is mediated by an organ of vital importance other than kidney, the organ in question being an SkQ1 target. In a model of compression brain ischemia/reperfusion, a single intraperitoneal injection of SkQR1 to a rat (1 μmol/kg a day before operation) effectively decreased the damaged brain area. SkQ1 was ineffective, most probably due to lower permeability of the blood-brain barrier to this compound.
The article is devoted to mathematical modeling of the dynamic stress-strain state of an elastoviscoplastic rotation shell of finite length upon impact on its face. The mathematical model based on S. ...P. Timoshenko's equations with using Binham's model. The impact is simulated by presence on face of the shell of depending of time stress. On the opposite end of the shell the boundary condition is a hard seal. The solution is presented in the form of third order of accuracy Taylor's row, constructed for the disturbed transfer wave fronts behind the incident and reflected from the boundary. Taylor's row consists of terms, which were obtained with using differentiation of modified S. P. timoshenko's equations. Under the taper degree refers to the difference of the radii at the ends of the shell divided by length. The article presents numerical results for various taper degrees.
Structure formation during solidification of a Pd-Ni-Cu-P melt is studied. It is demonstrated that changes in the heat transfer conditions lead to a nonlinear change in the characteristics of the ...structure. The article presents the regimes of cooling the samples and the results of their structure and composition studies. It is found that a decrease in the cooling rate of the alloy leads to an increase in the size, proportion and composition of nanoinclusions in an amorphous matrix. X-ray diffraction method, electron probe microanalysis, transmission microscopy and scanning calorimetry are used for samples characterization. This article is part of the theme issue 'Transport phenomena in complex systems (part 2)'.
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