The sensitivity of luminescence thermometry is enhanced at high temperatures when using a three-level luminescence intensity ratio approach with Dy- activated yttrium aluminum perovskite. This material was synthesized via the Pechini method, and the structure was verified using X-ray diffraction analysis. The average crystallite size was calculated to be around 46 nm.
View Article and Find Full Text PDFBackground: Gold-based complexes represent a new class of potential metallodrugs. Although their action mechanism is not entirely understood, it was shown that gold complexes inhibit some enzymes' activities. Among them, Na,K-ATPase is emerging as an essential target for various anticancer drugs.
View Article and Find Full Text PDFA promising way to improve the performance of luminescent materials is to combine them with noble metal nanoparticles. Herein, a set of silver/europium-doped lanthanum orthophosphate (Ag/LaEuPO) nanostructures with different concentrations of silver nanoparticles were prepared and investigated. The presented overlap between the strongest europium (Eu) excitation line and the broad silver nanoparticle surface plasmon resonance makes the combination prospective for coupling.
View Article and Find Full Text PDFFluorescence excitation-emission matrices were measured for 111 samples of different types of beer and studied by the parallel factor analysis (PARAFAC). The 5-component PARAFAC model was found to suitably describes the beer fluorescence, accounting for 99.4% of the fluorescence variance in the measured set of samples, and providing the completely resolved excitation and emission spectra of each component.
View Article and Find Full Text PDFThis paper presents parallel factor analysis (PARAFAC) of fluorescence of cereal flours. Excitation-emission matrices (EEM's) of different cereal flours (wheat, corn, rye, rice, oat, spelt, barley and buckwheat) were measured in a front-face configuration over the ultraviolet-visible spectral range. EEM's showed that flours strongly fluoresce in two spectral regions, where amino acids, tocopherols, pyridoxine and 4-aminobenzoic acid show intense emissions.
View Article and Find Full Text PDFJ Esthet Restor Dent
September 2016
Objective: The aim of this study was to evaluate changes of color and fluorescence of resin based composite exposed to beer.
Materials And Methods: 84 samples (13 mm in diameter and 1.5 mm thick) of microhybrid composite Gradia Direct extra bleach white were immersed in 5 different beers (dark and light) or distilled water.
Mater Sci Eng C Mater Biol Appl
January 2016
This study investigated the degree of conversion, depth of cure, Vickers hardness, flexural strength, flexural modulus and volumetric shrinkage of experimental composite containing a low shrinkage monomer FIT-852 (FIT; Esstech Inc.) and photoinitiator 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO; Sigma Aldrich) compared to conventional composite containing Bisphenol A-glycidyl methacrylate (BisGMA) and camphorquinone-amine photoinitiator system. The degree of conversion was generally higher in FIT-based composites (45-64% range) than in BisGMA-based composites (34-58% range).
View Article and Find Full Text PDFFluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) and Partial least squares Discriminant Analysis (PLS DA) were used for characterization and classification of honey. Excitation emission spectra were obtained for 95 honey samples of different botanical origin (acacia, sunflower, linden, meadow, and fake honey) by recording emission from 270 to 640 nm with excitation in the range of 240-500 nm. The number of fluorophores present in honey, excitation and emission spectra of each fluorophore, and their relative concentration are determined using a six-component PARAFAC model.
View Article and Find Full Text PDFNovel optical spectroscopy and imaging methods may be valuable in the early detection of cancer. This paper reports differences in the luminescence responses of pigmented skin lesions (melanomas and nevi) and apparently normal non-pigmented human skin, based on analyses of synchronous luminescence spectroscopy measurements. Measurements were performed in the excitation range of 330-545 nm, with synchronous intervals varying from 30-120 nm.
View Article and Find Full Text PDFFront-face synchronous fluorescence spectroscopy combined with chemometrics is used to classify honey samples according to their botanical origin. Synchronous fluorescence spectra of three monofloral (linden, sunflower, and acacia), polyfloral (meadow mix), and fake (fake acacia and linden) honey types (109 samples) were collected in an excitation range of 240-500 nm for synchronous wavelength intervals of 30-300 nm. Chemometric analysis of the gathered data included principal component analysis and partial least squares discriminant analysis.
View Article and Find Full Text PDFOpalized white tuff (OWT) with 40 μm average particle size and 39.3 m(2)/g specific surface area has been introduced into polyisoprene rubber (NR). Their reinforcing effects were evaluated by comparisons with those from precipitated silica (PSi).
View Article and Find Full Text PDFExcitation-emission matrices (EEM) and total synchronous fluorescence spectra (SFS) of normal and malignant breast tissue specimens are measured in UV-VIS spectral region to serve as data inputs in development of Support Vector Machine (SVM) based breast cancer diagnostics tool. Various input data combinations are tested for classification accuracy using SVM prediction against histopathology findings to discover the best combination regarding diagnostics sensitivity and specificity. It is shown that with EEM data SVM provided 67% sensitivity and 62% specificity diagnostics.
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