The creation of multi-stimuli-sensitive composite polymer–inorganic materials is a practical scientific task. The combination of photoactive magneto-piezoelectric nanomaterials and ferroelectric polymers offers new properties that can help solve environmental and energy problems. Using the doctor blade casting method with the thermally induced phase separation (TIPS) technique, we synthesized a hybrid polymer–inorganic nanocomposite porous membrane based on polyvinylidene fluoride (PVDF) and bismuth ferrite (BiFeO3/BFO). We studied the samples using transmission and scanning electron microscopy (TEM/SEM), infrared Fourier spectroscopy (FTIR), total transmission and diffuse reflection, fluorescence microscopy, photoluminescence (PL), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), vibrating-sample magnetometer (VSM), and piezopotential measurements. Our results demonstrate that the addition of BFO increases the proportion of the polar phase from 76.2% to 93.8% due to surface ion–dipole interaction. We also found that the sample exhibits laser-induced fluorescence, with maxima at 475 and 665 nm depending on the presence of nanoparticles in the polymer matrix. Furthermore, our piezo-photocatalytic experiments showed that under the combined actions of ultrasonic treatment and UV–visible light irradiation, the reaction rate increased by factors of 68, 13, 4.2, and 1.6 compared to sonolysis, photolysis, piezocatalysis, and photocatalysis, respectively. This behavior is explained by the piezoelectric potential and the narrowing of the band gap of the composite due to the mechanical stress caused by ultrasound.

Diffuse reflection spectra of biotissues in vivo and transmission and reflection coefficients for biotissues in vitro are measured over 300-800 nm. These data are used to determine the spectral absorption and scattering indices and the scattering anisotropy factor for stomach mucous membranes under normal and various pathological conditions (chronic atrophic and ulcerous defects, malignant neoplasms). The most important physiological (hemodynamic and oxygenation levels) and structural-morphological (scatterer size and density) parameters are also determined. The results of a morphofunctional study correlate well with the optical properties and are consistent with data from a histomorphological analysis of the corresponding tissues.Keywords: in vivo/in vitro tissues, pathology, spectrophotometry, diffuse reflection, absorption and scattering indices, scattering anisotropy factor, blood content, oxygenation, scatterer density and size.Introduction. In the development of new laser techniques in medicine, which require preliminary testing, exact information on the propagation of optical radiation in biological tissues is of primary importance. The propagation of light in tissue is determined by its optical parameters, specifically the absorption (μ a ) and scattering (μ s ) coefficients and the scattering anisotropy factor (g). Furthermore, these optical indices contain important information on the micro-and macrostructure of the medium being studied and its constituents, as well as on its physiological, morphological, and biochemical parameters, and are key factors in the solution of basic and applied problems in biotechnology [1][2][3][4][5].Determining the optical indices of biological tissues is an extremely time-consuming task because of the complicated structure of biotissues, themselves, and the variety of ways photons interact with them. Most biological objects, including plant and animal tissue, are optically turbid, randomly inhomogeneous media, for which the scattering index can be hundreds of times the absorption index [1-3]. Because of this, separating the contributions of absorption and scattering to the attenuation of the intensity of light becomes a very difficult problem.At present there are two approaches to studying the optical parameters of biological objects in steady-state spectroscopy: spatial probing and classical spectrophotometry. The first involves measuring the diffuse reflection coefficient with spatial resolution and analyzing the data in the approximation of a semi-infinite medium with a diffusion or P 3 -approximation for the radiative transfer equations [3,6]. The second approach involves measuring the optical transmission and reflection coefficients assuming media with finite thicknesses and solving the inverse problem for the radiative transfer equations in various numerical or analytical model approximations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Although the experimental and theoretical approaches are well developed, these methods have a number of well-known and mutu...

No abstract

Diffuse reflection spectra, diffuse and collimated transmittance spectra of the mucous tissue of stomach anthrus in norm and at a low-differential form of stomach cancer are measured in 300–800 nm spectrum range. The optical coefficients of absorption (μa), scattering (μs) and anisotropy factor (g) for tissues with pathological changes have been calculated by the three-flux model and diffusion approximation methods. It has been determined that the magnitude of optical parameters grows with the development of malignant processes in stomach tissues which indicates the prevalence of forward light scattering and the increase in Mi scatter contribution to the total scattering coefficient of malignant tissues. It has also been shown that the application of two independent theories as methods of tissues' optical parameters determination (μa,μs,g) gives satisfactorily similar results.

The electrochemical method was used to synthesize hematite (α-Fe2O3 nanoparticles in the 0.1 M NaCl solution. The α-Fe2O3 were synthesized by dissolution the iron anode with formation the Fe(OH)x and its calcinations at different temperatures. The samples were characterized by means by X-ray diffraction (XRD), Raman and UV-vis spectroscopy, electron microscopy, EDX and FTIR. The photocatalytic oxidation of the mordant dye Chrome blue (CB) using electrochemical synthesize hematite was studied under ultraviolet light (UV-light) irradiations. The effect of hematite calcination temperature and hydrogen peroxide concentration on photocatalytic degradation of chrome blue was carried out. Increasing the annealing temperature are increases the degree of dye decolorization which connected with the gradually increasing proportion of the crystalline phase at the expense of the amorphous phase.