A comparative study of photocatalytic activity of Na+-Ag+ ion-exchanged glass-ceramics with metallic Ag, semiconductor AgBr, and hybrid Ag-AgBr nanoparticles.

Photocatalytic glass-ceramics doped with metallic Ag, semiconductor AgBr, and hybrid metal-semiconductor Ag-AgBr nanostructures were synthesized via low-temperature Na+-Ag+ ion exchange. The spectral features of the nanostructures in the silicate glass matrix as well as their photocatalytic performance were studied in detail. Glass-ceramics containing hybrid metal-semiconductor nanostructures were shown to possess one order of magnitude higher photocatalytic activity compared to their counterparts with metallic and semiconductor nanostructures. Hybrid metal-semiconductor nanostructures allow enhancement of the net density of photogenerated hot electrons.

[THE EFFICIENCY OF THERAPY WITH VITAMIN D METABOLITES OF STRUCTURAL AND FUNCTIONAL CHANGES IN THE BONE TISSUE IN WOMEN WITH ARTERIAL HYPERTENSION, OBESITY AND DEFICIENCY VITAMIN D].

The aim of work was to evaluate the efficacy of combination therapy with vitamin D metabolites on mineral bone density and markers of bone remodeling in postmenopausal women with arterial hypertension, obesity and vitamin D deficiency working in adverse environmental conditions. We examined 95 women aged from 48 to 60 years, 79 people (main group) had arterial hypertension, obesity and deficiency vitamin D and worked in adverse conditions of production, 16 were healthy women. The main group depending on the conducted treatment were divided into 3 groups: А group - received standard antihypertensive therapy, Cholecalciferol and Alfacalcidol; group B - standard antihypertensive therapy and Cholecalciferol; group C - standard antihypertensive therapy. The examination included anthropometric measurements (body weight, height, calculation of body mass index, waist circumference, hip circumference, calculation of index waist circumference / hip circumference), measurement of blood pressure, laboratory tests - determination of the 25-hydroxyvitamin D, parathyroid hormone, C-terminal telopeptide, osteocalcin, osteoprotegerin, instrumental study of mineral density of bone tissue (the definition of T-criterion). The dynamics of the level of 25-hydroxyvitamin D, parathyroid hormone, C-terminal telopeptide, osteocalcin, osteoprotegerin and mineral density of bone tissue after 6 and 12 months. The results showed a positive effect of Cholecalciferol and Alfacalcidol on the level of 25-hydroxyvitamin D, markers of bone formation in serum and parameters of mineral bone density in women. However, combination therapy with vitamin D metabolites showed a more pronounced effect on the processes of bone formation and mineral density of bone tissue (p<0.05). Found that the lack of correction of deficiency and insufficiency of vitamin D contributes to the progressive decrease in mineral density of bone tissue and disruption of the processes of bone formation. Combination therapy with vitamin D metabolites is effective (p<0.05) and pathogenetically justified in the treatment of vitamin D deficiency and structural and functional changes of bone tissue in postmenopausal women with arterial hypertension and obesity, working in adverse environmental conditions.

Photostructurable photo-thermo-refractive glass.

Photostructurable properties of photo-thermo-refractive glass are discovered for the first time. The etching kinetics in HF solutions for virgin photo-thermo-refractive glass and glass ceramics are investigated. The etching rate of the glass ceramics is shown to be more than ten times higher than that of glass. Future prospects of applying the chemical etching technology for developing various PTR glass-based photonic and mechatronic elements are discussed.

Evidence for an oxygen diffusion model for the electric pulse induced resistance change effect in transition-metal oxides.

Electric-pulse induced resistance hysteresis switching loops for Pr0.7Ca0.3MnO3 perovskite oxide films were found to exhibit an additional sharp "shuttle tail" peak around the negative pulse maximum for films deposited in an oxygen-deficient ambient. The resistance relaxation in time of this "shuttle tail" peak as well as resistance relaxation in the transition regions of the resistance hysteresis loop show evidence of oxygen diffusion under electric pulsing, and support a proposed oxygen diffusion model with oxygen vacancy pileup at the metal electrode interface region as the active process for the nonvolatile resistance switching effect in transition-metal oxides.

Is violation of Newton's second law possible?

Astrophysical observations (usually explained by dark matter) suggest that classical mechanics could break down when the acceleration becomes extremely small [the approach known as modified Newtonian dynamics (MOND)]. I present the first analysis of MOND manifestations in terrestrial (rather than astrophysical) settings. A new effect is reported: around each equinox date, 2 spots emerge on the Earth where static bodies experience spontaneous acceleration due to the possible violation of Newton's second law. Preliminary estimates indicate that an experimental search for this effect can be feasible.

Micro Photo Detector Fabricated of Ferroelectric-Metal Heterostructure.

The anomalous photovoltaic effect (APE) in ferroelectric thin films has been utilized for the development of an optical micro-detector active in the visible range (from 350 to 800 nm). La-doped Pb(Zr,Ti)O(3) (PLZT) ferroelectric films epitaxially grown on Pt(001)/Mg(001) substrate were fabricated into micro-detector arrays and characterized as to their optical response. The Au/PLZT/Pt/MgO device was self-polarized in the as-deposited form with the polarization vector perpendicular to film surface. The heterostructure photovoltage response ranged from 100 to 200 mV, and the photocurrent was ~30 nA/cm(2) for devices of ~250 µm diameter under illumination of 100 mW/cm(2) at wavelengths from 400 to 580 nm. Such micro-detectors can be used for optical sensors in MEMS devices as well as for electrical stimulators of biological cells.

Realization of a polarizer employing the combined effects of birefringence and diffraction.

A polarizer that uses the combined effects of birefringence and diffraction has been realized experimentally. A sheet of calcite was taken as the substrate, and a series of grooves with a sawtooth profile was manufactured on its surface by optical grinding and polishing. The sample polarizer shows good polarizing performance in test. The measured extinction ratio is better than 2 x 10(-4) and can be improved further.

Grazing Incidence XUV Spectroheliograph RES-C for the CORONAS-I Mission.

The RES-C grazing incidence XUV spectroheliograph has been developed in the P. N. Lebedev Physical Institute (FIAN) as a part of the CORONAS-I project. Its objective is to obtain images of the full Sun in monochromatic lines over the spectral range of 180–210Å, which includes prominent emission from ions of Fe VIII–Fe~XIII, O VI, and Fe XXIV. Here, we describe the optical scheme of the spectroheliograph, and show results of XUV testing of its individual component elements as well as of the complete assembled instrument. XUV measurements were made of the absolute diffraction efficiency and stray-light level for both holographic and mechanically ruled gratings, the spectral reflectivity of the multilayer-coated mirrors, the transmittance of the thin aluminum blocking filters, and the combined spectral efficiency of the whole instrument. The spectral and spatial resolutions of the spectroheliograph were measured by recording spectrally dispersed images of a laser plasma source in monochromatic lines of fluorine ions between 185–200Å. For comparison, we also present spectral images of the Sun obtained with the spectroheliograph as flown on the CORONAS-I satellite mission.

Hypometabolic and hypothermic factors from small intestine of hibernating ground squirrels (Citellus undulatus).

Low molecular mass components of the acetic acid extract from the small intestine of hibernating ground squirrels (Citellus undulatus) produced a decrease in oxygen consumption and body temperature of white mice and a dose-dependent delay in embryonic development of sea urchin (Strongylocentrotus intermedius). Equivalent doses of low molecular mass components obtained by the same method from active (summer) animals did not have such an effect.