New experimental limits on neutron - mirror neutron oscillations in the presence of mirror magnetic field

Present probes do not exclude that the neutron ($n$) oscillation into mirror neutron ($n'$), a sterile state exactly degenerate in mass with the neutron, can be a very fast process, in fact faster than the neutron decay itself. This process is sensitive to the magnetic field. Namely, if the mirror magnetic field $\vec{B}'$ exists at the Earth, $n-n'$ oscillation probability can be suppressed or resonantly amplified by the applied magnetic field $\vec{B}$, depending on its strength and on the angle $\beta$ between $\vec{B}$ and $\vec{B}'$. We present the results of ultra-cold neutron storage measurements aiming to check the anomalies observed in previous experiments which could be a signal for $n-n'$ oscillation in the presence of mirror magnetic field $B'\sim 0.1$~G. Analyzing the experimental data on neutron loses, we obtain a new lower limit on $n-n'$ oscillation time $\tau_{nn'} > 17$ s (95 % C.L.) for any $B'$ between 0.08 and 0.17 G, and $\tau_{nn'}/\sqrt{\cos\beta} > 27$s (95 % C.L.) for any $B'$ in the interval ($0.06\div0.25$) G

Hyperspectral system for Imaging of skin chromophores and blood oxygenation

We developed a compact, fast, hand-held hyperspectral imaging system for 2D neural network-based visualization of skin chromophores and blood oxygenation. Here, we present results of the system tests on healthy volunteers

Novel wearable VCSEL-based blood perfusion sensor

A wearable 850 nm VCSEL-based blood perfusion sensor operating on the principles of laser Doppler flowmetry (LDF) and Dynamic Light Scattering (DLS) has been developed and tested. The sensitivity of the sensor to changes in skin blood perfusion has been demonstrated

Sterile neutrino and dark matter

We consider the equation that describes the dynamics of the sterile neutrino density in primeval plasma. The analysis of this equation results in the 5% contribution of the sterile neutrino with mixing parameters $\Delta m^2_{14} = 7.3\text{eV}^2$ and $\sin^2 2\theta_{14} = 0.33$ to the energy density of the Universe. The considered parameters of the sterile neutrino correspond to the warm dark matter.Comment: 7 pages, 11 figure

Microstructure evolution and mechanical behavior of ultrafine Tie6Ale4V during low-temperature superplastic deformation

The influence of microstructure evolution on the low-temperature superplasticity of ultrafine Tie6Ale4V was established. For this purpose, the static and dynamic coarsening response and plastic-flow behavior of the alloy with a mean size of a (sub)grains and b particles of 0.1-0.4 μm were determined via a series of tension tests at temperatures between 450 and 700°

Non-invasive control of influence of polyethylene glycol on transport function of fluorescent colored liposomal nanoparticles

The studies were carried out on groups of clinically healthy mice line of outbred CD-1 stock. The model animals were divided into 2 groups and received experimental liposomal formulations. Using the method of fluorescence spectroscopy, we investigated the effectiveness of penetration into the circulatory system of fluorescently stained liposomes with polyethylene glycol (PEG) and without PEG when administered orally. Fluorescence channel with a fiber probe series of multifunctional laser non-invasive diagnostic system "LAKK-M" (SPE "LAZMA" Ltd, Russia) was used as the measuring equipment

Noninvasive control of the transport function of fluorescent coloured liposomal nanoparticles

The use of liposomal nanoparticles with an incorporated active substance is an innovative and promising approach to diagnostics and therapy. The application of liposomal nanoparticle-based drugs allows for targeted localized delivery, overcomes the natural barriers within the body effectively, and minimizes possible side effects. Liposomes are able to contain a variety of ingredients with practically no limitations to their chemical composition, chemical properties, or size of constituent molecules. This study evaluated the ability to control the passage of fluorescent dye-filled liposomes through the intestinal mucosal barrier after oral administration. For this purpose, the increase in transcutaneous registered fluorescence from tetrabromofluorescein dye was recorded and analysed. Fluorescence intensity was measured at the proximal end of the tail of an animal model after oral administration of the liposomes. Measurements were taken at the excitation wavelengths of 365 and 450 nm. The fluorescence intensity in the group treated with the fluorescent contrast agent encapsulated in liposomal particles increased 140% of the initial level, but in the group treated with pure contrast agent, the increase in detected fluorescence intensity did not exceed 110%. Mice that received empty liposomes as well as the control group did not demonstrate statistically significant changes in fluorescence intensity. A potential application of our results is an express laser optical method of monitoring the transport of orally administered liposomal particles. The results can be used to help create new optical tools for use in the development of new drugs and in high-throughput screening used during their testing

Evolution of microstructure and mechanical properties of Tibased metal-matrix composites during high-pressure torsion

The microstructure and microhardness evolution of a Ti/TiB and Ti15(wt.%) Mo/TiB metal-matrix composites (MMC) during high-pressure torsion (HPT) at 400 °C was studie