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Background and Objectives. There is a global trend towards an increase in the number of patients diagnosed with ovarian cancer during their reproductive years. One of the current clinical technologies is the technology of cryopreservation of removed healthy ovaries in order to preserve fertility and their subsequent transplantation after treatment for cancer of other organs. Glycerol is often used as a non-penetrating agent in freezing to improve follicle survival. Materials and Methods. The work examined the ovaries of cats with diagnoses confirmed by histological studies: follicular phase, luteal phase, serous carcinoma, leimyosarcoma. Diffuse reflectance spectroscopy was used to determine the kinetic parameters of dehydration and optical properties of tissues upon interaction with glycerol. Based on the change in mass over a long period of time, the diffusion coefficient of glycerol in the samples was determined. Results. The effective diffusion coefficient of interstitial water in cat ovarian tissue has been measured: D = (2.6 ± 0.4)·10−6 cm2/s (follicular phase), D = (3.3 ± 0.4)·10−6 cm2/s (luteal phase), D = (3.0 ± 0.3)·10−6 cm2/s (leiomyosarcoma), and D = (1.6 ± 0.2)·10−6 cm2/s (serous carcinoma), which is initiated within 1.5–2 hours of interaction. Diffusion of glycerol occurs over a long period of time, about 400 hours, and for the samples under study is: D = (8.3 ± 2.5)·10−8 cm2/s (follicular phase), D = (5.6 ± 1.7)·10−8 cm2/s (luteal phase), D = (2.2 ± 0.2)·10−8 cm2/s (leiomyosarcoma), and D = (1.1 ± 0.4)·10−7 cm2/s (serous carcinoma). Conclusion. The established perfusion-kinetic parameters of glycerol/interstitial water for the studied samples can be used in clinical practice in the preparation of ovarian tissue for transplantation (cryopreservation), in the transmembrane transfer of drugs, the development of new reproductive technologies, etc.

A comparative analysis of the diffuse reflectance spectra and their changes after irradiation with electrons with an energy of 30 keV of coatings based on polymethylphenylsiloxane resin and pigment powders of two-layer hollow ZnO/SiO2 particles is carried out. The analysis is performed in situ in the range of 250–2500 nm. The samples are irradiated using a Spectrum space-conditions simulator. The radiation resistance of the studied coatings based on two-layer hollow ZnO/SiO2 particles is estimated relative to coatings based on ZnO polycrystals by analyzing the difference diffuse reflectance spectra obtained by subtracting the spectra after irradiation from the spectra of the unirradiated samples. It is found that the intensity of the induced absorption bands in coatings based on hollow ZnO/SiO2 particles is less than in coatings based on ZnO microparticles, and the radiation resistance when estimating changes in the integral absorption coefficient of solar radiation (ΔαS) is twice as high. The increase in the radiation resistance is probably determined by the different nature of defect accumulation: in the case of solid microparticles, defects can accumulate inside grains; in hollow particles, the accumulation of defects can occur only within the thin shell of the sphere. [ABSTRACT FROM AUTHOR]

The results of comparative studies of the phase composition, diffuse reflectance spectra, radiation-induced absorption spectra, and the integral absorption coefficient of solar radiation upon irradiation of micro- and nanopowders of gadolinium oxide are presented. To assess the radiation stability of optical properties, the samples were placed in a chamber of an installation simulating space conditions, where diffuse reflection spectra were recorded in the range of 0.2–2.5 μm in a vacuum of 2 × 10–6 Torr before and after each period of electron irradiation (E = 30 keV, Φ = (1–3) × 1016 cm–2). Micropowders of rare earth elements are used to increase the radiation stability of materials by absorbing free electrons formed in them during irradiation during their transitions from the d- to f-shell. Nanopowders of rare earth elements added to micropowders of various compounds provide an additional mechanism for increasing radiation stability due to the annihilation of primary defects formed during irradiation on nanoparticles. The result obtained in this work is opposite to these mechanisms—the radiation stability of a micropowder is significantly (more than 4 times) higher compared to a nanopowder due to more intense absorption in the ultraviolet region for the nanopowder caused by their own defects. The paper gives an explanation of the results obtained. [ABSTRACT FROM AUTHOR]

Caffeine is the most widely consumed psychoactive substance worldwide, affecting numerous tissues and organs, with notable impacts on the central nervous system, heart, and blood vessels. The effect of caffeine on vascular smooth muscle cells is an initial transient contraction followed by significant vasodilatation. In this study we investigate the use of diffuse reflectance spectroscopy (DRS) for monitoring of vascular changes in human skin induced by caffeine consumption. DRS spectra were recorded on volar sides of the forearms of eight healthy volunteers at time intervals of 0, 30, 60, 120, and 180 min after consumption of caffeine, while one subject served as a negative control. Analytical diffusion approximation solutions for diffuse reflectance from three-layer structures were used to assess skin composition (e.g. dermal blood volume fraction and oxygen saturation) by fitting these solutions to experimental data. The results demonstrate that cutaneous vasodynamics induced by caffeine consumption can be monitored by DRS, while changes in the control subject not consuming caffeine were insignificant. [ABSTRACT FROM AUTHOR]

A series of mixed orthovanadates with nominal composition Lu0.5R0.5VO4 (R = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were synthesized by a solid-state reaction method in the three-stage annealing process. The single-phase powders with smaller Eu, Tb, Dy, Ho, Er, Tm, Yb were obtained after the second calcined stage at 1200 C for 5h, while for large Ce, Pr, Nd, Sm needed a third calcining. Rietveld refinement analysis of the crystal structure confirms a zircon-type structure (space group I41/amd). Furthermore, a linear dependence of the obtained lattice parameters on the ionic radius of the substituted lanthanide R was observed in the mixed Lu0.5R0.5VO4 series. The lattice parameters optimized by ab initio methods are slightly smaller than parameters obtained by Rietveld refinement, which can be explained by inaccuracies in the description of f-electrons using density functional theory (DFT). The transmission and diffuse reflectance spectra of mixed compounds Lu0.5R0.5VO4 are similar to such spectra obtained for corresponding orthovanadates RVO4. Both obtained spectra indicated significant differences in transmission/reflection intensities between samples annealed at 1200 °C and 1400 °C, but the band gap width remained unchanged, suggesting an improvement their crystallinity. Both experimental and theoretical results reveal a barely noticeable reduction in the band gap observed with a reduction of the ionic radius of the lanthanides. A thorough analysis of the electronic structure of the materials and diffuse reflectance spectra suggests that the position of the f-levels of lanthanides is the determining factor in the formation of valence and conduction bands. [ABSTRACT FROM AUTHOR]

Background and Objectives: The reproductive system of women is a subject of diverse multidisciplinary research worldwide. These are oncological diseases, infertility of an unspecified nature, ovarian cryopreservation to preserve fertility, improvement of early diagnosis of diseases, etc. Elucidation of the mechanisms of diffusion of tissue water and hyperosmotic agents in luteal phase ovarian tissues controlled by аngiogenic growth factors can bring us closer to understanding biophysical processes in general. Materials and Methods. The work used spectroscopy of diffuse reflection, a free diffusion model and the modified Bouguer–Lambert–Beer law. Results. The diffusion coefficient of 40% glucose/tissue water intothe ovariantissue ofthe luteal phase D andthe diffusion time τ have been determined, which was D = (8.6 ± 1.4)·107 cm2 /s and τ = 50.4 ± 1.7 min with a samplethickness of(0.8 ± 0.1)mm. The efficiency of optical clearing of cat ovariantissues with 40% glucose immersion has been determined. Conclusions. Studies have shown that 40%-glucose is an effective optical clearing agent for topical use in differentiating normal and pathological ovarian tissues and in clinical applications.

Lanthanides (Ce, Pr, Nd and Gd) 1, 3, 5 and 10 wt% of each were loaded into a pristine sodium aluminium phosphate glass matrix in order to simulate the immobilization of minor actinides (Am, Np, Cm) produced from spent nuclear fuel reprocessing. The optical parameters pertaining to these glasses were derived from the diffuse reflectance spectra. The systematic dependence of the physical and structural properties of these glasses on the dopants and the concentration of the latter was studied by XRD and Raman spectroscopy. The results on Rare Earth (RE) doped sodium aluminium phosphate are being reported for the first time. The physical parameters such as density, molar volume and oxygen packing density were evaluated. The XRD patterns showed the absence of any crystalline phase in these glasses. The relative % areas of (PO3)−2(Q2) bonds increase, whereas Q0 and Q1 tend to decrease with the addition of lanthanide oxides as compared to the pristine glass. The addition of different lanthanide oxides was found to depolymerize the network by forming more Q2 short chains. The results showed that the band gap energy (Eg) depends strongly on the cation field strength (CFS) of the lanthanides. The band gap energy decreases with an increase in the lanthanide concentration in the glass matrix. Praseodymium-doped glasses showed the highest Eg values (5.28–5.23 eV). The photoluminescence spectra confirm the characteristic excitation and emission peaks for the cations Ce+3, Pr+3 and Gd+3 and their variation with concentration was analysed. [ABSTRACT FROM AUTHOR]

Noninvasive assessment of skin structure using hyperspectral images has been intensively studied in recent years. Due to the high computational cost of the classical methods, such as the inverse Monte Carlo (IMC), much research has been done with the aim of using machine learning (ML) methods to reduce the time required for estimating parameters. This study aims to evaluate the accuracy and the estimation speed of the ML methods for this purpose and compare them to the traditionally used inverse adding-doubling (IAD) algorithm. We trained three models – an artificial neural network (ANN), a 1D convolutional neural network (CNN), and a random forests (RF) model – to predict seven skin parameters. The models were trained on simulated data computed using the adding-doubling algorithm. To improve predictive performance, we introduced a stacked dynamic weighting (SDW) model combining the predictions of all three individually trained models. SDW model was trained by using only a handful of real-world spectra on top of the ANN, CNN and RF models that were trained using simulated data. Models were evaluated based on the estimated parameters' mean absolute error (MAE), considering the surface inclination angle and comparing skin spectra with spectra fitted by the IAD algorithm. On simulated data, the lowest MAE was achieved by the RF model (0.0030), while the SDW model achieved the lowest MAE on in vivo measured spectra (0.0113). The shortest time to estimate parameters for a single spectrum was 93.05 μs. Results suggest that ML algorithms can produce accurate estimates of human skin optical parameters in near real-time. [ABSTRACT FROM AUTHOR]

The characteristics of modern portable spectrometers based on photodetector arrays make it possible to create on their basis a new class of devices for operational control of the optical properties of various media. The introduction into the practice of diffuse reflectance spectroscopy with spatial resolution is hampered by the lack of an analysis of the influence of the width of the spectral region used and other sources of measurement uncertainty on the unambiguous determination of the optical properties of finely dispersed scattering materials. This article describes a method of determining the coefficient of local diffuse reflection and calculating the spectral parameters of the reduced scattering and absorption of radiation based on the differences in their shape, which are clearly manifested in a wide range of the spectrum. This allows the reduction in the determination of the desired spectral dependencies to the formation of a residual function that requires varying the values of only two parameters. A method for normalising the recorded spectral dependencies is described, which makes it possible to minimise the influence of the spectral characteristics of the equipment used on the recorded spectral–spatial profiles. Approbation of the method was carried out on examples of processing spectral–spatial diffuse reflection profiles of four samples of finely dispersed scattering structural materials, as well as diffuse reflection profiles of living tissue in the palm thenar region. The sources of uncertainty that affect the uniqueness of the obtained solutions are found, and solutions are proposed to minimise their influence on the desired spectral dependencies. The results obtained indicate the prospects of using the described method for creating equipment for non-destructive control of the optical properties of finely dispersed materials and media, including living tissues and food products. [ABSTRACT FROM AUTHOR]

Goethite/hematite ratios in soils are widely used to reconstruct past climatic changes, but their accurate measurements have remained challenging due to the matrix effect. Here we present a new method for measuring soil goethite/hematite ratios by characterizing the band position of electron pair transition (EPT) based on the diffuse reflectance spectra processed by continuum removal. We introduce a "half‐band‐area wavelength", λ1/2, to characterize the EPT band position and validate the method using synthetic standards made from mixing pure goethite and hematite and four sets of goethite‐ and hematite‐free matrices derived from arid aeolian deposits and tropical saprolite. A consistent λ1/2‐goethite/hematite relation across four matrices demonstrates that our method eliminates the matrix effect. We further validate our method by applying it to quantify goethite/hematite ratios in 180‐Kyr loess‐paleosol sequences and comparing the results to the reported paleoclimatic records. Our new method is promising for improving the measurement of goethite/hematite ratios in sediments. Plain Language Summary: Hematite (α‐Fe2O3) and goethite (α‐FeOOH) are common iron oxides in soils and sediments. Their formation processes are sensitive to climatic conditions such as soil humidity. Thus, goethite/hematite ratios in terrestrial and marine deposits have been widely used to infer past climatic changes. However, their use relies on the accurate quantification of goethite/hematite ratios, which has been challenging using existing methods. Conventional X‐ray diffraction methods have high detection limits, whereas rock magnetic methods are limited by the weak magnetization of these minerals and the difficulty in converting magnetic moments to moles. Instead, methods based on diffuse reflectance spectra (DRS) have been frequently used to directly quantify goethite/hematite ratios given the high sensitivity, but major uncertainties exist due to the interference from the sample matrix. We developed a new DRS‐based method to quantify goethite/hematite ratios by characterizing the band position of electron pair transition (EPT). We find consistent statistically significant correlations between a proxy derived from the EPT band positions and goethite/hematite ratios across synthetic standards of different soil matrices, supporting that our method eliminates the matrix effect. Overall, we provided a promising method for precisely quantifying goethite/hematite ratios in soil and sediments. Key Points: We present a new method for measuring goethite/hematite ratios using the band positions of electron pair transitionThe electron pair transition band position characterized by λ1/2 is determined solely by the goethite/hematite ratios, not their contentsThe new method is independent of soil matrices and is validated by synthetic and geological samples [ABSTRACT FROM AUTHOR]

Abstract Goethite/hematite ratios in soils are widely used to reconstruct past climatic changes, but their accurate measurements have remained challenging due to the matrix effect. Here we present a new method for measuring soil goethite/hematite ratios by characterizing the band position of electron pair transition (EPT) based on the diffuse reflectance spectra processed by continuum removal. We introduce a “half‐band‐area wavelength”, λ1/2, to characterize the EPT band position and validate the method using synthetic standards made from mixing pure goethite and hematite and four sets of goethite‐ and hematite‐free matrices derived from arid aeolian deposits and tropical saprolite. A consistent λ1/2‐goethite/hematite relation across four matrices demonstrates that our method eliminates the matrix effect. We further validate our method by applying it to quantify goethite/hematite ratios in 180‐Kyr loess‐paleosol sequences and comparing the results to the reported paleoclimatic records. Our new method is promising for improving the measurement of goethite/hematite ratios in sediments.

The method of immersion optical clearing reduces light scattering in tissues, which improves the use of optical technologies in the practice of clinicians. In this work, we studied the optical and molecular diffusion properties of cat ovarian tissues in the follicular (F-ph) and luteal (L-ph) phases under the influence of glycerol using reflectance spectroscopy in a broad wavelength range from 200 to 800 nm. It was found that the reflectance and transmittance of the ovaries are significantly lower in the range from 200 to 600 nm than for longer wavelengths from 600 to 800 nm, and the efficiency of optical clearing is much lower for the ovaries in the luteal phase compared to the follicular phase. For shorter wavelengths, the following tissue transparency windows were observed: centered at 350 nm and wide (46 ± 5) nm, centered at 500 nm and wide (25 ± 7) nm for the F-ph state and with a center of 500 nm and a width of (21 ± 6) nm for the L-ph state. Using the free diffusion model, Fick's law of molecular diffusion and the Bouguer–Beer–Lambert radiation attenuation law, the glycerol/tissue water diffusion coefficient was estimated as D = (1.9 ± 0.2)10−6 cm2/s for ovaries at F-ph state and D = (2.4 ± 0.2)10−6 cm2/s—in L-ph state, and the time of complete dehydration of ovarian samples, 0.8 mm thick, as 22.3 min in F-ph state and 17.7 min in L-ph state. The ability to determine the phase in which the ovaries are stated, follicular or luteal, is also important in cryopreservation, new reproductive technologies and ovarian implantation. [ABSTRACT FROM AUTHOR]

Understanding tumors and their microenvironment are essential for successful and accurate disease diagnosis. Tissue physiology and morphology are altered in tumors compared to healthy tissues, and there is a need to monitor tumors and their surrounding tissues, including blood vessels, non‐invasively. This preliminary study utilizes a multimodal optical imaging system combining hyperspectral imaging (HSI) and three‐dimensional (3D) optical profilometry (OP) to capture hyperspectral images and surface shapes of subcutaneously grown murine tumor models. Hyperspectral images are corrected with 3D OP data and analyzed using the inverse‐adding doubling (IAD) method to extract tissue properties such as melanin volume fraction and oxygenation. Blood vessels are segmented using the B‐COSFIRE algorithm from oxygenation maps. From 3D OP data, tumor volumes are calculated and compared to manual measurements using a vernier caliper. Results show that tumors can be distinguished from healthy tissue based on most extracted tissue parameters (p<0.05). Furthermore, blood oxygenation is 50% higher within the blood vessels than in the surrounding tissue, and tumor volumes calculated using 3D OP agree within 26% with manual measurements using a vernier caliper. Results suggest that combining HSI and OP could provide relevant quantitative information about tumors and improve the disease diagnosis. [ABSTRACT FROM AUTHOR]

The color characteristics of organosilicate coatings of various colors are analyzed before and after field tests in Vietnam in a tropical marine climate. The effect of pigments (Cr2O3, SrCrO4, MoCrO4) for color fastness and weather resistance of coatings is demonstrated. [ABSTRACT FROM AUTHOR]

Manganese (Mn)‐modified bismuth potassium titanate, i.e., Bi0.5K0.5Ti1−xMnxO3 (x = 0, 0.05, 0.10, and 0.15), compounds are fabricated by a mixed‐oxide method. The Rietveld analyses of X‐ray diffraction data and the Raman spectroscopy support the formation of the compounds in the tetragonal phase. The crystallite and the grain size are found to be higher for compounds having more oxygen vacancies. With increase in Mn concentration, the bulk resistance decreases drastically and the energy bandgap reduces. The dielectric constant increases substantially with substitution of Mn. The analysis of complex impedance spectroscopy confirms the non‐Debye‐type relaxation mechanisms in the compounds. Based on the activation energy of the conduction process, analysis of leakage current, and energy‐dispersive X‐ray spectroscopy (EDX) data, the ionization of oxygen vacancy and the hopping of trapped electrons between multivalent Ti and Mn ions in electrical properties of the compounds are discussed. The compounds follow the correlated barrier hopping conduction mechanism. While the leakage current in Bi0.5K0.5TiO3 fits the Poole–Frenkel model, that in Mn‐substituted samples exhibits Ohmic conduction mechanism. [ABSTRACT FROM AUTHOR]

A comparative analysis of the diffuse reflectance spectra in the range from 200 to 2500 nm is carried out on aluminum-oxide microspheres, microparticles and nanoparticles exposed to irradiation with protons and electrons with energies of 100 keV. It is established that the amount of intrinsic absorption centers in the microspheres is higher compared to microparticles and nanoparticles, while the concentration of induced absorption centers is lower. [ABSTRACT FROM AUTHOR]

Coordination compounds of iron(II) and nickel(II) with 3-amino-4-ethoxycarbonylpyrazole (L), FeL2A2 (A = Cl– (I), (II)), [FeL2(NCS)2(H2O)2] (III), and NiL2Br2 (IV), are synthesized. The compounds are studied by X-ray diffraction analysis, IR spectroscopy, and UV spectroscopy (diffuse reflectance spectra). A single crystal is observed for complex III, and its crystal structure is determined by X-ray structure analysis (СIF file CCDC no. 1857220). It is shown that L coordinates to the metal via the monodentate mode by the N(2) atom of the pyrazole cycle. The study of the temperature dependence µeff(Т) in a temperature range of 2–300 K shows exchange interactions of the antiferro- or ferromagnetic character between the M2+ ions in the complexes. The type of exchange interactions depends on the composition of the compound. [ABSTRACT FROM AUTHOR]

The adulteration of meat products using colourants and curing agents has heightened concerns over food safety, thereby necessitating the development of advanced detection methods. This study introduces a deep-learning-based spectroscopic method for swiftly identifying counterfeit beef altered to appear fresh. The experiment involved 60 beef samples, half of which were artificially adulterated using a colouring solution. Despite meticulous analysis of the beef's colour attributes, no significant differences were observed between the fresh and adulterated samples. However, our method, utilising a 344–1040 nm spectral range, achieved a classification accuracy of 98.84%. To enhance practicality, we employed gradient-weighted class activation mapping and identified the 580–600 nm range as particularly influential for classification. Remarkably, even when we narrowed the input to the model to this spectral range, a high level of classification accuracy was maintained. To further validate the model's robustness and generalisability, we allocated 70 beef samples to an external validation set. Comparative performance analysis revealed that our model outperformed traditional machine learning algorithms, such as SVM and logistic regression, by 9.3% and 28.4%, respectively. Overall, this study offers invaluable insights for detecting counterfeited beef, thereby contributing to the preservation of meat product quality and integrity within the food industry. • Novel deep-learning-driven spectroscopic approach for identifying adulterated beef. • Diffuse reflectance spectra of adulterated beef differ from those of fresh beef. • Gradient-weighted class activation mapping identified 580–600 nm as significant. • The 580–600 nm spectral region holds critical information on beef quality. • Model's robustness and applicability validated through external validation set. [ABSTRACT FROM AUTHOR]

Three cobalt(II) coordination polymers containing compounds {Co(3-mboba)(1,2-bix) 2 } n ( 1 ), {Co 2 (1,3-pda)(px3ampy)(H 2 O) 2 } n ( 2 ), {Co 2 (hfipbb) 2 (bpbix) 2 } n ( 3 ), that are formed from three different bent carboxylic acids [3,3′-methylenebis(oxy)dibenzoic acid (3-H 2 mboba), 2,2′-(1,3-phenylene)diacetic acid (1,3-H 2 pda) and 4,4′-(perfluoropropane-2,2-diyl)dibenzoic acid (H 2 hfipbb)] as primary ligands and three different {N,N}-donor linkers [1,2-bis((1H-imidazol-1-yl)methyl)benzene(1,2-bix), N,N′-(1,4-phenylenebis(methylene)) dipyridin-3-amine (px3ampy) and 4,4′-bis((1H-imidazol-1-yl)methyl)biphenyl (bpbix)] as secondary ligands, have been synthesized under hydrothermal conditions. Compounds 1 – 3 are characterized by single crystal X-ray diffraction analysis, IR spectroscopy, thermogravimetric (TG) and elemental analysis. Single crystal X-ray crystallography shows that diverse metallo-macrocycles are formed in compounds 1 , 2 and 3 . In the crystal structure of compound 1 , two different metallo-macrocyles, 28-membered metal–acid {Co 2 (3-mboba) 2 } ring and 24-membered metal-N-linker {Co 2 (1,2-bix) 2 } ring, are formed. The alternative arrangement of these macrocylic rings leads to the formation of 1D chainlike coordination polymer (compound 1 ). In the crystal of compound 2 , a 25-membered macrocycle ring {Co(1,3-pda)(px3ampy)} is formed from one dicarboxylic acid ligand and one {N,N}ligand, which further undergoes coordination with itself resulting in the formation of 1D chain. The {Co 3 (hfipbb)(bpbix) 2 } metallamacrocycle, observed in the crystal structure of compound 3 , is more diversified in the sense that it is relatively bigger in size and this trinuclear metallo-macrocycle is formed by one dicaryboxylic acid ligand and two {N,N} donor linkers, but not in a plane. Interestingly, the inter-linking of these non-planar macrocycles results in the construction of a supramolecular pipe. [ABSTRACT FROM AUTHOR]

Two interpenetrated coordination polymers (CPs) {[Zn1(L)(NO2pbda)]n[Zn2(L)(NO2pbda)]n} (1) and [Zn(L)(Brpbda)]n (2) were prepared by reactions of zinc sulfate heptahydrate with N-donor ligands of 1,4-di(1H-imidazol-4-yl)benzene (L) and auxiliary carboxylic acids of nitroterephthalic acid (H2NO2pbda) and 2,5-dibromoterephthalic acid (H2Brpbda), respectively. The structures of the CPs were characterized by Fourier-Transform Infrared (IR) spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The coordination polymer 1 has two different (4, 4) sql 2D layer structures based on the [Zn(L)(NO2pbda)] moiety, which results in inclined interpenetration with a 2D + 2D → 3D architecture, while the CP 2 exhibits a 3-fold interpenetrating dmp network. The diffuse reflectance spectra are also investigated for the CPs 1 and 2.

Mechanical pressure superficially applied on the human skin surface by a fiber-optic probe influences the spatial distribution of blood within the cutaneous tissues. Upon gradual load of weight on the probe, a stepwise increase in the skin reflectance spectra is observed. The decrease in the load follows the similar inverse staircase-like tendency. The observed stepwise reflectance spectra changes are due to, respectively, sequential extrusion of blood from the topical cutaneous vascular beds and their filling afterward. The obtained results are confirmed by Monte Carlo modeling. This implies that pressure-induced influence during the human skin diffuse reflectance spectra measurements in vivo should be taken into consideration, in particular, in the rapidly developing area of wearable gadgets for real-time monitoring of various human body parameters. [ABSTRACT FROM AUTHOR]

Phototherapy is a renowned treatment for curing skin diseases since ancient times. Phototherapeutic treatment for psoriasis and many other diseases require narrow band ultra violet-B (NB-UVB) light with peak intensity at 313 nm to be exposed to the affected part of body. In this paper, we report combustion synthesis of NB-UVB − 313 nm emitting Ca 9 Mg(PO 4 ) 6 F 2 phosphors doped with Gd 3 + , Pr 3 + and Li + ions. The phase formation was confirmed by obtaining X-ray diffraction (XRD) pattern and morphology was studied with the Scanning electron microscopy (SEM) images. Photoluminescence (PL) emission spectra show intense narrow band emission at 313 nm under 274 nm excitation wavelengths. Emission intensity was enhanced when Ca 9 Mg(PO 4 ) 6 F 2 compound is co-doped with Pr 3 + ions. Excitation spectra of Ca 9 Mg(PO 4 ) 6 F 2 :Gd 3 + , Pr 3 + doped samples shows broad excitation in ultra violet C (UVC) region. Diffuse reflectance spectra (DRS), obtained by UV–visible spectrophotometer, measures the absorption properties of the material. By applying Kubelka Munk function on the diffuse reflectance spectra, band gap of the material is determined. PL decay curves were examined which indicates efficient energy transfer between Pr 3 + and Gd 3 + ions. Charge compensation effect was also studied by co-doping Li + ion in host. Emission intensity was found to increase with the addition of charge compensator. The prepared phosphor has potential to convert UVC light into NB-UVB. The luminescence intensity of Gd 3 + shows remarkable increase when it is sensitized with Pr 3 + , and an addition of charge compensator in the form of Li + , show even better results. This phosphor surely has the potential to be used as phototherapy lamp phosphor. [ABSTRACT FROM AUTHOR]

Zincochromite nanoparticles ( NPs) were precipitated on surfaces of the as-prepared Al2O3 micron-sized particles by a heterogeneous precipitation technique using urea as a homogeneous precipitation agent. This procedure leads to decrease the pore diameter and increase the pore volume and specific surface area ( a s), realizing the potential access to ZnCr2O4 catalytic sites. Although the obtained band gap energy (Eg) of Al2O3-ZnCr2O4 composite is about 2.3 eV (more than ZnCr2O4), the absorbance is enhanced about 1.5 orders of magnitude. These characteristics make it an effective photocatalyst of inorganic dyes from an aqueous media. Dye removal performance of the nanocomposite powder is higher than that of pure ZnCr2O4, which is attributed to an increase in the photocatalytic sites and the absorbance intensity. It was believed that the surface area created from Al2O3 support realized the potential access to ZnCr2O4 catalytic sites. To confirm these assertions, X-ray diffractometry ( XRD), scanning electron microscopy ( SEM), diffuse reflectance spectroscopy ( DRS), and N2 adsorption-desorption analysis were applied. [ABSTRACT FROM AUTHOR]

The objective of this paper is to evaluate the penetration and accumulation of SiO 2 nanoparticles (NPs) in vitro human placental tissue as a function of NP size and electroporation (EP) and microneedle (MN) treatments. The results show that the penetration and accumulation of SiO2 NPs has a significant influence on the optical properties. Optical coherence tomography (OCT) monitoring and diffuse reflectance (DR) spectra measurements indicate that 30 nm SiO2 NPs have a tendency to generate greater signal intensities, while 15 nm NPs penetrated faster and had a higher penetration depth. The reduction in average attenuation coefficients of human placental tissue when the SiO 2 NPs size is constant is found to show the following trend: SiO2 NPs in combination with EP and MN treatment $>$ SiO 2 NPs in combination with MN $>$ SiO 2 NPs with EP $>$ only SiO2 NPs. It can be concluded that EP and MN treatments dramatically increase the penetration of SiO 2 NPs into human placental tissue. The results prove that OCT and DR spectra can be combined with EP and MN treatments to establish a theoretical basis for the safe use of SiO 2 NPs on human placental tissue and can potentially become a powerful tool for early diagnosis and monitoring of tissue diseases. [ABSTRACT FROM PUBLISHER]

A series of Pr 3+ activated alkaline-sodium-phosphate (NaMPO 4 , where M = Mg, Ca, Sr and Ba) phosphors were prepared by conventional solution combustion method with the fixed doping concentration of Pr 3+ (1.0 mol%). The crystal phase formation and morphology of the phosphates were analyzed by X-ray powder diffraction (XRD) and field emission scanning electron microscope (FE-SEM), respectively. The optical properties including reflectance, excitation and emission and the color coordinates were investigated. The band gap of the phosphors was calculated from diffuse reflectance spectra data using the Kubelka–Munk function. The photoluminescence (PL) excitation spectra showed the excitation peaks ranging from 420 to 475 nm and emission peaks were observed in the visible region and were found to vary for different hosts. Pr 3+ -doped phosphors can display very distinct dominant red emission due to the 3 P 0 → 3 H 5 , 3 P 0 → 3 H 6 , 1 D 2 → 3 H 4 and 1 D 2 → 3 H 5 transitions. The Pr 3+ PL emission spectrum was observed from NaMPO 4 phosphors at 605 nm. This emission under 445 nm excitation makes these materials possible candidates to serve as sources of red light in tricolor system used for solid state lighting. Different results on the luminescence features of Pr 3+ :NaMPO 4 are discussed on the basis of crystal structure. The Pr 3+ ion has structure-dependent transitions due to the special microstructures present in a given host. The results indicated that among the four different alkaline cations, Ca +2 not only provides the most intense emission from Pr 3+ but it also produces electric-dipole dominated transition ( 3 P 0 → 3 H 5 ) resulting in the most intense reddish-orange emission. [ABSTRACT FROM AUTHOR]

One way to improve photo- and radiation resistance of materials is by the modification of their nanoparticles. The purpose of work is to study the optical properties and radiation resistance of ZrO 2 powder mixtures with SiO 2 nanoparticles without high-temperature heating. The ZrO 2 powders with micron sizes were mixed in a ratio of 100:7 mas.% with SiO 2 nanopowders. The nanopowders were obtained by combustion of silicon tetrachloride in air plasma. Samples were characterized using X-ray diffraction (XRD), high resolution scanning electron microscopy (SEM), and a simulator of the environment of outer space “Spectrum”. The radiation resistance increase of zirconia dioxide powders with micron-sized grains by the addition of silica nanoparticles without heating at a high temperature was found. For these purposes only water evaporation at 150 °C was used. The effectiveness of the modification reaches values of 2.1 times. This value is close to or even more in comparison to its values in the modification by using high-temperature heating. This result is significant for the practical use of this method of incensement of the radiation resistance of oxide reflecting powders. [ABSTRACT FROM AUTHOR]

One of the marks left by prehistoric man in the Amazonas landscape are the dark-colored soil stains, Archeological Dark Earth (ADE), which are rich in organic matter, phosphorus and calcium. The color in this soil is presented as an attribute of difficult interpretation on the horizon, and the studies towards a better identification are important. In this sense, the objective of this study was to characterize the color and iron oxides of the ADE clay fraction in Apuí region in southern Amazonas. Six trenches were opened, where these profiles were characterized morphologically, and also samples were collected per horizon for later performance of grain size analysis, flocculation, water clay dispersion and chemicals (pH in water and potassium chloride, calcium, magnesium, potassium, phosphorus, potential acidity, f, organic carbon and organic matter) and mineralogical analyses. The data were submitted to principal component analysis. Similar behavior in the studied profiles was found both in physical and chemical attributes. It was concluded that the hematite and goethite, determined by x-ray diffraction and diffuse reflectance spectroscopy, besides not presenting significant variations between the studied soils, present similar characteristics to non-anthropogenic Brazilian soils. The color measured by diffuse reflectance spectroscopy proved efficient to indicate variations among the ADEs, proving to be an innovative technique, efficient and promising for indirect quantification of soil characteristics in a simple and low cost manner. The results show that iron oxides demonstrate be sensitive indicators of pedoenvironmental conditions and pedogenic processes of Archeological Dark Earth. [ABSTRACT FROM AUTHOR]