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Aim To investigate an interaction between the calcium and sulphide signalling pathways, particularly effects of the slow H2S release donor morpholin-4-ium-4-methoxyphenyl-(morpholino)-phosphinodithioate ( GYY4137) on the expression of inositol 1,4,5-trisphosphate receptors ( IP3R) with the possible impact on the apoptosis induction in HeLa cells. Methods Gene expression, Western blot analysis, apoptosis determination by Annexin- V- FLUOS and drop in mitochondrial membrane potential by 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolyl-carbocyanine iodide ( JC1) and immunofluorescence were used to determine differences in control and GYY4137-treated He La cells. Results In He La cell line, GYY4137 (10 μ m) up-regulated expression of the IP3 R1 and IP3 R2, but not IP3 R3 on both m RNA and protein levels. Concurrently, cytosolic calcium increased and reticular calcium was depleted in concentration-dependent manner, partially by the involvement of IP3 R. Depletion of calcium from reticulum was accompanied by increase in endoplasmic reticulum ( ER) stress markers, such as X-box, CHOP and ATF4, thus pointing to the development of ER stress due to GYY4137 treatment. Also, GYY4137 treatment of He La cells increased the number of apoptotic cells. Conclusion These results suggest an involvement of H2S in both IP3-induced calcium signalling and induction of apoptosis, possibly through the activation of ER stress. [ABSTRACT FROM AUTHOR]

Kinetic equations for the electromagnetic drift modes are derived and analyzed for the stability of tokamaks in the local approximation. In the dissipationless, hydrodynamic limit, the fifth-order polynomial dispersion relation previously studied is recovered. The kinetic velocity space integrals in the ion dynamics are shown to modify the five principal modes of oscillation and their polarizations. It is shown that in kinetic stability theory the critical plasma pressure defined in magnetohydrodynamic theory determines a transition from microinstability to macroinstability. [ABSTRACT FROM AUTHOR]

The multiplicity distributions of charged particles produced from π, K and $$\bar p$$ interactions with the nuclei Li, C, S, Cu, CsI, Pb at 40 GeV/c were studied. It was found that the linear relation D=a〈n〉+b is satisfied for the distributions of different kinds of secondary particles including knocked out protons. Consequently, the use of the scaling variable z′=(an+b)/(a〈n〉+b) ensures the scaling of the distributions with respect to the mass number A at least up to the second moment. [ABSTRACT FROM AUTHOR]

It is shown that ion temperature gradient driven turbulence supports fluctuations with broader radial scales than those inferred previously on the basis of mixing length arguments derived from the eigenfunction with lowest radial eigenmode number. These fluctuations of greater radial extent are more strongly excited and are shown to result in fluctuation levels and transport coefficients that can be considerably larger than those previously predicted. It is expected that transport of this nature would maintain ion temperature and density profiles near marginal stability in neutral beam heated and ion cyclotron resonance heated plasmas. [ABSTRACT FROM AUTHOR]

Differential rotation characteristic of the tandem mirror central cell is shown to have a significant stabilizing effect on the rotation and unfavorable curvature driven drift modes. Stability boundaries and parametric dependence of the growth rate and frequency of the m=1 and m=2 modes are given as a function of the passing electron density fraction, wall-to-plasma radius, and rotation speed. [ABSTRACT FROM AUTHOR]

Nonlinear equations describing the flute dynamics of rotating plasma are derived and solitary vortex solutions are obtained. The solution takes the form of a shielded dipole vortex, similar to that found for nonlinear Rossby waves. The nonlinear dispersion relation, relating propagation speed to vortex radius, is obtained. Vortex speeds are shown to take values complementary to the phase velocities of the linear modes of the system. The E×B circulation velocity of the plasma trapped in the vortex is comparable to the diamagnetic drift velocity in the equilibrium plasma. [ABSTRACT FROM AUTHOR]

Equilibria with minimum energy are constructed from a variational principle in which the potential energy of a plasma is minimized, subject to a small set of global invariants. These invariants are preserved exactly, by ideal motions of the plasma, and approximately, by a tearing mode of the m = 1, n = 1 type. Estimates of decay rates for the energy and the invariants are given. A tokamak window with low q and zero current on the boundary is found and shown to be ideally and resistively stable. The reversed-field pinch (RFP) window and the transition region between the two windows is found to be unstable to high-n modes. [ABSTRACT FROM AUTHOR]

Turbulence associated with sheared radial electric fields such as those arising in tokamak edge plasmas is investigated analytically. Two driving mechanisms are considered: in the region of maximum vorticity (maximum electric field shear), the electric field is the dominant driving mechanism. Away from the maximum, turbulence is driven by the density gradient. In the latter case, previous work is extended to include the effects of the electric field on the spatial scales of density correlation in the frequency-Doppler-shifted, density-gradient-driven turbulence. For radial-electric-field-driven turbulence, the effects of magnetic shear on linear instability and on fully developed turbulence are examined. In the case of weak magnetic shear, saturation occurs through an enstrophy cascade process which couples regions of driving and dissipation in wavenumber space. For stronger magnetic shear, such that the width of the dissipation region resulting from parallel resistivity is comparable to the radial electric field scale length, saturation occurs through nonlinear broadening of the mode structure, which pushes enstrophy into the region of dissipation. Estimates of mode widths, fluctuation levels, and scalings are obtained for both mechanisms. Comparison is made with the results of fluctuation measurements in the TEXT tokamak [Phys. Fluids 27, 2956 (1984)]. [ABSTRACT FROM AUTHOR]

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There are many sources of free energy available in the form of heat that is often simply wasted. The aim of this paper is to design and build a low temperature differential Stirling engine that would be powered exclusively from heat sources such as waste hot water or focused solar rays. A prototype is limited to a low temperature differential modification because of a choice of ABSplus plastic as a construction material for its key parts. The paper is divided into two parts. The first part covers a brief history of Stirling engine and its applications nowadays. Moreover, it describes basic principles of its operation that are supplemented by thermodynamic relations. Furthermore, an analysis of applied Fused Deposition Modelling has been done since the parts with more complex geometry had been manufactured using this additive technology. The second (experimental) part covers 4 essential steps of a rapid prototyping method - Computer Aided Design of the 3D model of Stirling engine using parametric modeller Autodesk Inventor, production of its components using 3D printer uPrint, assembly and final testing. Special attention was devoted to last two steps of the process since the surfaces of the printed parts were sandpapered and sprayed. Parts, where an ABS plus plastic would have impeded the correct function, had been manufactured from aluminium and brass by cutting operations. Remaining parts had been bought in a hardware store as it would be uneconomical and unreasonable to manufacture them. Last two chapters of the paper describe final testing, mention the problems that appeared during its production and propose new approaches that could be used in the future to improve the project.

This contribution presents a new methodology of fatigue tests evaluation based on digital image correlation application. The full-field strain analysis brings the possibility of 3D strain measurement evaluation on a curved part of specimen standardly used under axial-torsional loading. Resulting strain response curves can subsequently serve for evaluation of cyclic plasticity model predictions. The crucial idea is the way of FE model creation to can evaluate simulation in the same points of the structure as in the DIC measurement. The new methodology saves amount of material and leads to a shorter experimental time.

We have described the pre- and postgadolinium MR appearance in one case of acute myositis ossificans. The unenhanced sequences can be helpful in excluding malignancy, particularly when viewed serially. While use of gadolinium allowed primary sarcoma to be ruled out in this case, it was not useful in the exclusion of early abscess formation or necrotic metastasis. [ABSTRACT FROM AUTHOR]