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.
We performed a search for a new generic X boson, which could be a scalar (S), pseudoscalar (P), vector (V), or an axial vector (A) particle produced in the 100 GeV electron scattering off nuclei, e− ...Z → e− ZX, followed by its invisible decay in the NA64 experiment at CERN. No evidence for such a process was found in the full NA64 dataset of 2.84 × 1011 electrons on target. We place new bounds on the S, P, V, A coupling strengths to electrons, and set constraints on their contributions to the electron anomalous magnetic moment ae,|ΔaX|≲ 10−15 –10−13 for the X mass region 1 MeV ≲ mX ≲ 1 GeV. These results are an order of magnitude more sensitive compared to the current accuracy on a e from the electron g − 2 experiments and recent high-precision determination of the fine structure constant.
Results of numerical simulations for acceleration of proton beams at the irradiation of Al target by a superintense laser pulse are presented. There is a good agreement with the experimental data in ...a broad range of laser intensities from
W/cm
to
W/cm
at the fixed laser pulse duration. The obtained parameters of proton beams were used for calculation of the total yield of
particles and neutrons for the nuclear reactions
B(
) and
B(
)
C at the collisions of proton beams with boron targets. It is shown that the number of
particles escaping boron target and arriving at track detectors is less than 5
of the total amount of
particles, because the majority of these particles remain inside the target owing to ionization losses. The derived values of the yield of
particles’ which arrive at detectors are in good agreement with the experimental data. We also calculate the total yield of neutrons in the reaction
B(
)
C. It is found that, at the intensity
W/cm
of the picosecond laser pulse, the yield is equal to
, this value is approximately of 3
of the total yield of
particles.
The results of investigations of spark plasma sintering (SPS) kinetics of tungsten carbide nanopowders with different Co content (0.3, 0.6, and 1.0 wt%) and graphite (0.3 and 0.5 wt%) are described. ...The α-WC nanopowders were obtained by direct current (DC) arc plasma synthesis followed by annealing in hydrogen. Ultrathin Co layers were deposited onto the nanoparticles by a chemical-metallurgical method from a salt solution. The excess carbon was introduced by mixing the WC-Co powders with graphite that resulted in the increase of the oxygen concentration. The carbonization of the tungsten carbide hard alloy specimens was demonstrated to take place in SPS. It resulted in different phase compositions, along with hardness within surface and central layers of sintered ceramic specimens. The effects of the initial particle size, of the Co concentration, and of the graphite one on the stages of the SPS of the ultra-low Co hard alloys were studied. The specimens with uniform fine-grained structure, increased density, and improved mechanical characteristics were obtained. The hardness Hv for WC-0.6%Co-0.3%C hard alloy with averaged grain size 1.0–1.5 μm was 20.2–20.5 GPa at the minimum fracture toughness coefficient KIC = 9.2–10.4 MPa m1/2.
•Intense sintering of the WC-Co nanoparticles at Stage II takes place via the creep of cobalt according to Coble.•The sintering of the particles at Stage III-1 goes via the creep, the intensity of which depends on the volume diffusion.•The sintering of the particles at Stage III-2 goes via the diffusion of carbon along the grain boundaries in WC carbide.•The positive effect of graphite is compensated by an increased oxygen concentration at the surfaces of the WC-Co particles.•The specimens have high hardness (20.2–20.5 GPa) and increased fracture toughness (9.2–10.4 MPa m1/2).
The results obtained by experimentally and theoretically studying the yield of the promising nuclear-fusion reaction
B(
) initiated by powerful picosecond laser radiation of intensity
W/cm
are ...presented. A new procedure that relies on a simultaneous detection of the yield of alpha particles and the neutron yield in the reference reaction
B
C and which permits reaching a high precision of measurements is employed. The measured alpha-particle yield per pulse in the reaction
B(
) is 10
particles in 4
sr at the above laser-pulse parameters. The results of a numerical particle-in-cell (PIC) simulation of the nuclear-fusion reaction
B(
) proceeding in a solid-state boron target are presented. These results on the alpha-particle yield per pulse in the reaction
B(
) agree fairly well with experimental results.
Electron capture into the mode of synchronous gyromagnetic autoresonance in a combined mirror-type magnetic trap with a high-frequency field in a cylindrical resonator is studied. The averaged ...equations of motion of electrons in such a trap are obtained taking into account the terms of the first order of smallness in the high-frequency field amplitude. An equation for the resonant phase, which has the form of an equation for a nonlinear oscillator with a constant force, is derived to change the magnetic field with time according to a linear law in a weakly relativistic approximation. Based on the analysis of its solutions, a general criterion for the electron capture into the gyromagnetic autoresonance mode is obtained. Using the Bogolyubov method, the change in the energy of particles is studied, taking into account the time dependence of the parameters of the combined trap. It is shown that during autoresonance, the change in the electron energy with time occurs synchronously with the change in the magnetic field.
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