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General increase of longevity in Ukraine and around the world along with the increasing number of women over 50 necessitates implementation of comprehensive scientifically based programs aimed to improve health and quality of life of this part of population. The aim of this review of international and Ukrainian studies was to investigate in depth hormone associated mechanisms of pathologic conditions formation in peri- and postmenopausal women. Materials and methods. Studies on association of climacteric symptoms and symptoms of dental pathology were analyzed. Results. Our literature review showed worse condition of dental health in menopausal women. The pres­ence of estrogen receptors in oral mucosa and salivary glands increases the risk of dental pathology when ovarian function diminishes. Gradual decrease of ovarian steroids in female body causes changes in oral microbiota and changes microbial landscape of periodontal pockets and effects local immunity. This causes increase of oral mucosa pathology such as glossodynia or burning mouth syndrome, lichen planus and angular cheilitis. It also causes the increase of periodontal diseases rate. Conclusions. Cross-disciplinary interaction of dentists and gynecologists-endocrinologists will provide possibilities to discover more common causes and pathogenic mechanisms of periodontal diseases and oral mucosa in menopausal women. This will provide possibilities for the development of comprehensive approach to diagnosis, treatment and prophylaxis.

Fe-doped TiO2 (2, 5, 10, 15 and 20% wt. of Fe) photocatalysts have been synthesized by sol-gel method using titanium aquacomplex precursor. The structure and morphology have been characterized by XRD, BET, SEM, and EDS analyses, Mossbauer and IR spectroscopies. XRD analysis confirmed the anatase structure. The introduction of ferric ions into the titania structure causes its amorphization. The crystallite sizes of obtained samples are around 3 nm. Fe-doped TiO2 samples possess mesoporous structure and high specific surface area (from 274 m2g-1 for 5Fe-TiO2 to 416.4 m2g-1 for 20Fe-TiO2). Mossbauer spectroscopy data confirms the incorporation of Fe3+ ions in the anatase structure. Photocatalytic degradation of Congo red dye using Fe-doped TiO2 photocatalysts was studied under the UV-A light. Optimized conditions for photocatalytic degradation of CR in the presence of hydrogen peroxide are obtained. It was found that the 2Fe-TiO2 sample in the presence of 20 mM H2O2 solution showed highest efficiency in dye photodegradation (99.4%) under UV-A light. The photodegradation kinetics was analyzed using a smartphone and fits well with first-order kinetics model.

Cobalt ferrite nanoparticles were obtained by the green synthesis method using extracts of grape peel and grape pulp. The obtained samples have been investigated by means of X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), and Mossbauer spectroscopy. All samples contain pure CoFe2O4 with the cubic spinel structure of the space group Fd3m. XRD analysis indicates that cobalt ferrite nanoparticles synthesized using grape peel extract and grape pulp extract have crystallite sizes of ~ 5 and ~ 25 nm, respectively. Cation distribution and crystalline structure parameters of the samples were calculated on the basis of Mossbauer spectroscopy data. After annealing, the CoFe2O4 sample obtained with grape pulp extract has a higher degree of inversion than that obtained with grape peel extract. The decrease in the degree of inversion is related to a decrease in the average size of crystallites. The CoFe2O4 sample synthesized using grape peel extract is a more active catalyst for the decomposition of hydrogen peroxide. The first-order rate constants are 1.11·10−4 s−1 and 3.43·10−4 s−1 for the CoFe2O4-pulp and CoFe2O4-peel samples, respectively. A 100 mM H2O2 solution was decomposed to 97.4%. The surface morphology of the cobalt ferrites remains unchanged after the catalytic decomposition of H2O2. The synthesized cobalt ferrites can be used in Fenton processes as stable magnetic catalysts.

In this paper, the effect of SnO2 impurity on the surface charge and adsorption properties of TiO2 samples is investigated. The experimental value of the zero charge point for TiO2 with 3%, 6% and 12% of SnO2 equals 3.53, 3.97 and 3.2, respectively. The adsorption activity of the samples was studied on model solutions of the anionic dye – Congo red. The maximum adsorption capacity (qexp) equals 24.6 mg/g for 3Sn/TiO2, 25.0 mg/g for 6Sn/TiO2 and 39.1 mg/g for 12Sn/TiO2. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to describe the adsorption mechanism of Congo red dye on the surface of Sn/TiO2 samples. Based on the results of the studies of Congo red adsorption by the surface of titanium dioxide doped with Sn, all samples agree best with the Langmuir model. The correlation coefficients for the Langmuir isotherms are in the range of 0.9927 - 0.9996, while the values ​​of R2 for the Freundlich and Dubinin-Radushkevich isotherms are in the range of 0.721 - 0.8329 and 0.8283 - 0.9433, respectively. Experimental data obtained from adsorption isotherms show that the TiO2 sample containing 12% SnO2 is the most active. The best result of Congo red removal occurred at a concentration of Co = 5 mg/l (% of removed dye ≈ 83% for 12Sn/TiO2; 81% for 6Sn/TiO2 and 71% for 3Sn/TiO2). Therefore, the studied samples of TiO2 doped with SnO2 can be used as effective adsorbents of Congo red from aqueous solutions.

Color images taken by a smartphone camera were used to estimate the rate of advanced photo-oxidation reaction of Direct Red 23 (DR23) azo dye as a model organic pollutant. The red, green, blue color coordinates were tested to quantify the dye. Images of the reaction mixture were taken at specified intervals to obtain kinetic lines and reaction rate constants. Both the reaction rate constant and the final degree of degradation were plotted as functions of the photocatalyst dose and the concentration of H2O2. The smartphone measurements are fully consistent with the reference spectrophotometry data. The maximum degradation efficiency of the DR23 dye was recorded at C0(H2O2) = 2.5 mM and photocatalyst dose equal to 1.0 mg/L. Higher H2O2 concentrations reduce the degradation rate as a result of the side reaction of H2O2 with OH radicals. A two-factor experimental design was used to study the effects of photocatalyst dose and H2O2 concentration with five and seven levels, respectively. The analysis of variance results indicated that the concentration of H2O2 had the greater influence. The smartphone provides quick and easy measurement of the photodegradation rate directly in the solutions without sampling. The proposed approach can be applied under field conditions in wastewater treatment plants. Highlights Smartphone-based colorimetry was used to determine the DR23 dye.; Dye decomposition rate was used to optimize TiO2 dose and H2O2 concentration.; The proposed approach can be useful in optimizing advanced photo-oxidation processes.

In this paper, the synthesis of spinel magnesium ferrite (MgFe2O4) nanoparticles is reported, along with its structural, magnetic and hyperthermic properties, which ensure them being effectively used in various fields. Firstly, magnesium ferrite was synthesized via sol-gel auto-combustion method, using honey as the reducing agent. The crystallite size was calculated via the Scherrer method, the modified Scherrer method, the Williamson-Hall method, and the size-strain plot (SSP) method. X-ray analysis was used to confirm the structure of the spinel. For morphological study of ferrite nanoparticles, scanning electron microscopy (SEM) was used. Finally, hyperthermic properties of magnesium ferrite were analyzed for potential usage in medicine. According to these results, spinel magnesium ferrite (MgFe2O4) nanoparticles proved to be suitable for destruction of cancer cells, as they can be heated to the desired temperature, which will increase the sensitivity of those cells.

Zinc ferrite (ZF) was obtained by a green synthesis using the Ginkgo Biloba extract as reductant and fuel. ZF was characterized by XRD, SEM, EDS, and IR-spectroscopy. The XRD analysis indicates tha...

The oxidative degradation of Rhodamine B dye under ultraviolet irradiation was studied. The degradation rate was measured with using of smartphone camera. Photocatalytic degradation of the Rhodamine B dye over the P25-TiO2 catalyst has been found to accelerate substantially in the presence of hydrogen peroxide. The relationship between the photocatalytic degradation rate and H2O2 concentration has been studied. The optimal concentration of H2O2 has been found to in the range of 10-25 mM. The proposed mixture of P25 photocatalyst and H2O2 oxidizer can be used to remove organic pollutions from industrial waste water.

This paper presents the experimental results on the impact of modified coal fly ash on mechanical performance of cement materials. Fly ash used in the experiments was received from Burshtyn thermal power plant (Ukraine). The surface modification was carried out by the acidic treatment in order to increase its pozzolanic activity. The impact of raw fly ash and surface-modified fly ash on the cement mortar strength have been compared. It was found in the experiments that the replacement of cement by 5% (wt) of modified fly ash increase the compressive strength value from 61.3 MPa to 63.2 MPa compared to unmodified fly ash at age 28 days. The mineral phase formation, structure and chemical compositions of the modified fly ash/cement composites were analyzed by XRD, SEM and EDS. This research is of great importance and opens a new way for the future investigation and utilization of coal fly ash.

Magnesium aluminate nanoparticles were prepared by the sol–gel autocombustion method using mixture of alanine and urea as a fuel. The sample was characterized using XRD, FE-SEM, EDS, and IR spectroscopy. XRD analysis confirmed the formation of single-phase spinel compound with average particle size of 28 nm estimated from FE-SEM analysis. IR spectrum revealed the stretching vibration of MA-O and MB-O bonds at 517 and 691 cm−1 respectively. The adsorption process of Congo Red dye on the spinel surface was studied under static conditions using UV–Vis spectrophotometry. The maximum equilibrium adsorption capacity obtained from the Langmuir model was calculated 24.5 mg∙g−1. In addition, the salicylic acid and mixture of polyaromatic hydrocarbons as polar and nonpolar compounds, respectively, were used to investigate the adsorption properties of MgAl2O4 by liquid chromatography (UFLC) analysis. The results suggest that the magnesium aluminate can be used as efficient adsorbent for anionic dyes and polar compounds due tothe presence of active centers on its surface.

A simple approach to test photocatalyst activity has been described. Photocatalytic degradation of a model dye was measured using a smartphone. The color changes were registered directly in the micro-photoreactor. The model dye Rhodamine B was degraded under UV irradiation (365 nm). The effect of H2O2 concentration and titanium dioxide photocatalyst dosage has been studied. Among three color systems, RGB, CIE L*a*b* and HSV, the first one proved to be the most suitable for the dye determination. The reference measurements were carried out with a UV-Vis spectrophotometer. Two smartphones and two tablets with different camera resolutions have been examined. The best calibration curve was obtained using a Samsung Galaxy A6 smartphone with a 16MP camera. The t-test has shown with 95 % confidence that there are no significant differences between the dye concentrations measured with the smartphone and spectrophotometer. The values of the relative standard deviation of the smartphone measurements were less than 0.5 %. Therefore, the proposed method for fast estimation of photocatalyst activity can be used in the control of advanced oxidation reactions.

TiO2-based nanomaterials are attracting much attention in many areas, such as photocatalysis, photoelectricity, probing, electrochromism, photochromism, etc. They are widely used in paints, polymers, sunscreens, and toothpaste. There are various ways of synthesis that affect the size, shape, and crystallinity of TiO2 nanoparticles. The main methods of obtaining titanium dioxide (with the structure of anatase, rutile or brookite) in the form of spheres, rods, fibers, and tubes include: sol-gel technology, hydrothermal and solvothermal methods, microwave method involving high-frequency electromagnetic waves, template method, electrodeposition, a sonochemical method using ultrasound, chemical and physical vapor deposition, "green" methods, etc. This literature review presents modern scientific results on the production of TiO2 nanoparticles by various methods.

Blue-colored ceramic nanopigments with the composition of CoAl2O4 were synthesized by solution combustion method using glycine (CoAl2O4-Gly), poly(vinyl alcohol) (CoAl2O4-PVA) and urea (CoAl2O4-Urea) as reductants and fuels. The morphology and chemical composition of the nanopigments were studied using SEM and EDS, respectively. The composition of the crystalline phase was examined using XRD. The crystallite sizes were calculated using the modified Scherrer method, Williamson-Hall method and size-strain plot method. Particles of the CoAl2O4-PVA sample have smaller crystallite sizes, whereas particles of the CoAl2O4-Urea sample have larger crystallite sizes. Thermal gravimetric analysis showed that thermal decomposition of cobalt(II) and aluminum nitrates is accompanied by the release of gases. As a result of material loosening, finely dispersed powders with high porosity were formed. FTIR-spectra of all the nanopigments contain absorption bands related to stretching vibrations of the Me-О bonds (400-700 cm−1). Stretching and deformation vibrations of water molecules are present as well. Color characteristics of the obtained nanopigments depend on the fuel used for the combustion synthesis. The pigment CoAl2O4-PVA has saturated blue-green color. The obtained spinel-type nanomaterials possess high suspension stability and can be used as pigments in ceramic technology.

Honey green synthesis of CoCrxFe2−xO4 (x = 0.0 − 1.0) ferrites with increasing Cr content was done by sol-gel auto-combustion method, without any post-preparation thermal treatment. Nanocrystalline...

Increased request for metal and metal oxide nanoparticles nanoparticles has led to their large-scale production using high-energy methods with various toxic solvents. This cause environmental contamination, thus eco-friendly “green” synthesis methods has become necessary. An alternative way to synthesize metal nanoparticles includes using bioresources, such as plants and plant products, bacteria, fungi, yeast, algae, etc. “Green” synthesis has low toxicity, is safe for human health and environment compared to other methods, meaning it is the best approach for obtaining metal and metal oxide nanoparticles. This review reveals 12 principles of “green” chemistry and examples of biological components suitable for “green” synthesis, as well as modern scientific research of eco-friendly synthesis methods of magnetic and metal nanoparticles. Particularly, using extracts of green tea, fruits, roots, leaves, etc., to obtain Fe3O4 NPs. The various precursors as egg white (albumen), leaf and fruit extracts, etc., can be used for the „green” synthesis of spinel magnetic NPs. “Green” nanoparticles are being widely used as antimicrobials, photocatalysts and adsorbents. “Green” magnetic nanoparticles demonstrate low toxicity and high biocompatibility, which allows for their biomedical application, especially for targeted drug delivery, contrast imaging and magnetic hyperthermia applications. The synthesis of silver, gold, platinum and palladium nanoparticles using extracts from fungi, red algae, fruits, etc., has been described.

In this study, hierarchical-structured Co3O4 nanocapsules and various rare earth metal (La, Nd, Gd, Sm)–doped Co3O4 materials were synthesized by a polymer-assisted combustion route. These rare earth metal–doped Co3O4 materials were tested as active electrode materials for high performance electrochemical supercapacitors. The Sm-Co3O4 electrode has shown an extraordinary electrochemical supercapacitor performance with high specific capacitance and exhibited a good cycling stability with the capacitance retention of 93.18% after 5000 cycles. The doping of rare earth metals in Co3O4 can reduce the charge transfer resistance and crystalline nature which are expected to improve the transfer of ions and electrons. Also, the large number of structural defects can promote the diffusion of electrolyte ion and electrochemical supercapacitance behavior. Furthermore, the antistructural modeling has shown that isovalent cation substitution leads to the formation of cation vacancies and interstitial defects, which enhance the electrochemical properties of doped Co3O4 materials.

Mesoporous titania samples modified by sodium arsenate to form arsenate functionalities were synthesized using titanium aqua complex [Ті(ОН2)6]3+·3Cl− and salt Na3AsO4 as precursors. The structure, morphology, and texture of the samples were characterized using XRD, IR spectroscopy, TG-DTA, TEM, and nitrogen adsorption methods. The adsorption properties of the samples located in the aqueous media were analyzed with respect to Sr(II) removal. The modified titania samples have a large specific surface area (up to 405 m2/g) and appropriate pore volume (up to 0.26 сm3/g) with a major contribution of mesopores. The maximum adsorption capacity of modified titania (with 4% of arsenate groups) towards Sr(II) is 262.9 mg/g. It is much smaller for unmodified titania (92.1 mg/g). The equilibrium adsorption isotherms were fitted using the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. The results revealed that the adsorption equilibrium data match with the Langmuir isotherm model (R2 > 0.993) that corresponds to the localized adsorption onto uniform surface. The adsorption kinetics fitted well by the pseudo-second-order kinetic model. A possible adsorption mechanism was analyzed. Sr(II) removal can be attributed to = Ti(О2AsОOН) groups located at a mesopore surface of the adsorbents. The materials demonstrate the stability of the degree of the Sr(II) adsorption during ten cycles. Thus, arsenate-modified mesoporous titania could be considered as an effective adsorbent for Sr(II) removal from wastewater.

Effect of Zn addition in Mg0.7−xZnxNi0.3Fe2O4 (with x = 0.0–0.7) prepared via solution combustion technique have been studied in terms of structural, magnetic properties, cationic distribution and surface morphology. X-ray diffraction (XRD) (with crystallite size (D)

Adsorption of metal species Ba(II), Sr(II), Zn(II), Ca(II), and Mg(II) and anions Cl−, Br−, and I− at a surface of unmodified and partially silylated nanosilica A-300 was studied in aqueous media upon changes in the degree of substitution of silanols to trimethylsilyl groups (ΘTMS) at ΘTMS = 0.272–0.483. The cation adsorption increases in series Sr(II)

Nanoparticles of Zn 1−x Ni x Fe 2 O 4 (x = 0.0–1.0 in step of 0.2) ferrites are synthesized by microwave combustion method using glycine as a fuel. The structure, site occupancy and ferrimagnetic behavior have been characterized by X-ray diffraction (XRD), Mossbauer Spectroscopy (MS) and Vibrating Sample Magnetometer (VSM). Special emphasis is given to the information provided by each of these techniques concerning the impact of the site occupancy on the magnetic properties. The results reveal the formation of single phase cubic spinel with crystallite sizes in the range of 30–42 nm. The lattice constants and the lattice strains decrease gradually with increasing Ni-content. Two well-defined Mossbauer sextets in the spectra at 78 K belong to octahedral [B] and tetrahedral (A) sites, respectively, confirming the formation of Zn 1−x Ni x Fe 2 O 4 spinel. The isomer shift (δ Fe ) values were assigned to Fe 3+ ions distributed in both A and B sites. The quadrupole splitting (Δ) values showed also that the orientation of the magnetic hyperfine field (H int ) with respect to the principle axes of the electric field gradient (EFG) is random. The nanosize samples In the presence of an externally applied magnetic field prepared exhibit the hysteresis loops of the ferrimagnetic nature. The value of saturation magnetization increases with introducing Ni up to x = 0.8 and then it decreases. The magnetic data parameters of this structure are discussed as a function of the content of Ni ions.

Effect of swift heavy ion irradiation on MgFe2O4 (annealed at 450 °C/3 h) sample prepared by a sol–gel auto-combustion procedure has been studied. Single phase samples were irradiated with 120 MeV 28Si9+ with ion fluence: 1 × 1011, 1 × 1012, and 1 × 1013 ions/cm2 to monitor its effect on the structure, cation distribution, and magnetic properties. Electronic energy loss induced modifications of cation distribution, structural, magnetic properties were examined by XRD, VSM, FE-SEM, and EDS. XRD measurements show the formation of single phase nanocrystalline mixed cubic spinel structure (grain size 31–35 nm). Observed slight changes of experimental lattice parameter with increasing irradiation dose is ascribable to the migration of Mg2+ ions (ionic radius: 0.071 nm) from B to A site with simultaneous migration of Fe3+ ions (ionic radius: 0.063 nm) from A to B site. Sample irradiated at a lower fluence (1 × 1011 ions/cm2) has higher specific surface area (S), is more suitable for catalytic activity. Irradiation leads formation of dead layer, thus affects magnetic properties, via spin canting at surface. Therefore, irradiation can be used to control both structural, magnetic properties. SEM images display agglomerated nano-particles, while EDS pattern confirms the presence of Mg, Fe and O elements in the sample. First time the antistructural modeling for magnesium ferrite is reported to get information on active surface centers.

Bariatric surgery is very efficacious in treating severe obesity. However, its effect on menstruation and ovulation is currently unknown. The purpose of this study was to assess the effect of gastric sleeve resection (GSR) on menstrual pattern in women with stages III–IV obesity and ovulatory dysfunction compared with conventional management. This was a prospective, multicentre, non-randomized trial, in premenopausal women, who fulfilled the criteria for gastric sleeve resection (GSR). Both women with and without polycystic ovary syndrome (PCOS) were evaluated at 3, 6, 9, 12 and 15 months post-surgery. Menstrual cycle irregularities were identified in 122 severely obese women (60 with PCOS; 62 without PCOS). The % total weight loss was greater with GSR than with conventional management (33.4% vs. 3.6% in PCOS; 24.8% vs. 3.6% in non-PCOS, respectively). Intermenstrual interval was shortened towards normal length (≤ 35 days) both in PCOS and non-PCOS GSR groups, by the 6th and 12th post-surgical month, respectively. Furthermore, ovulation at 6 months was achieved in 63.6% of PCOS and 45% of non-PCOS subjects post-GSR, which was higher than in controls (11.1% and 13.6%, respectively; p

Color images taken by a smartphone camera were used to estimate the rate of advanced photo-oxidation reaction of Direct Red 23 (DR23) azo dye as a model organic pollutant. The red, green, blue color coordinates were tested to quantify the dye. Images of the reaction mixture were taken at specified intervals to obtain kinetic lines and reaction rate constants. Both the reaction rate constant and the final degree of degradation were plotted as functions of the photocatalyst dose and the concentration of H

Designing and fabrication of smart hybrid multifunctional materials for energy/fuel production and environmental detoxification is indeed of great significance for sustainable development. Herein, we synthesized a new well-structured S-scheme heterostructure Fe@TiO

Cobalt-zinc ferrite nanoparticles were synthesized using environmentally friendly approach with quince extract as a reducing agent. Crystal structure and morphology of the obtained materials were studied by XRD, SEM-EDS, Mössbauer and IR spectroscopy. The synthesized nanoparticles have a cubic spinel structure and crystallite size ranging from 5 to 9 nm. The infrared spectra contain characteristic absorption bands for the M

The magnesium-zinc ferrites Mg1-xZnxFe2O4 (x = 0…1) were studied as magnetic sorbents for environmental applications. Low-temperature Mossbauer spectroscopy was used to determine the distribution of magnesium and ferric ions in the spinel crystal lattice. The influence of Zn content on magnetic parameters was investigated on the basis of VSM data. As the molar ratio of zinc to magnesium increases from 0 to 1, the pHPZC value decreases from 10.5 to 8.9. Langmuir and Freundlich models were used to check whether single-layer or multi-layer adsorption occurs. The adsorption of Cr(VI) and Ni(II) ions is well fitted by the Langmuir equation. To check the physical or chemical nature of the sorption process, the Dubinin-Radushkevich equation was used. It was found that the processes of adsorption of Cr(VI) and Ni(II) ions are of a chemical nature. The best Cr(VI) ion adsorption capacity was found for the Mg0·2Zn0·8Fe2O4 sample (qe = 30.49 mg/g). The percentage of heavy metal removal by the mixed ferrite samples increases with increasing zinc content. The most effective sorbent for Ni(II) removal is the Mg0·4Zn0·6Fe2O4 sample (93.2%). Modeling the antistructure provides deeper insight into the mechanism of heavy metal adsorption. The obtained magnesium-zinc ferrites are promising magnetic adsorbents for removing chromate and nickel ions from the environment.

The effect of cobalt precursors (cobalt acetate and cobalt nitrate) on the phase stability and evolution of morphology of La-doped Ni0.5Co0.5Fe2O4 nanopowders prepared via sol-gel auto-comb...