Spectral
Mostrando 13-24 de 2608 artigos, teses e dissertações.
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13. Structure of prodigiosin from Serratia marcescens NJZT-1 and its cytotoxicity on TSC2-null cells
Abstract Prodigiosin, a secondary metabolite extracted from Serratia marcescens (S. marcescens), could induce apoptosis in various cancer cells, with however low toxicity on normal cells. The red pigment was extracted from a strain S. marcescens NJZT-1 isolated from soil, which had antibacterial activity. Spectral analyses (LC-ESI-MS, UV-VIS spectrophotometr
Food Sci. Technol. Publicado em: 2021-06
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14. Determination of carrageenan in jellies with new methylene blue dye using spectrophotometry, smartphone-based colorimetry and spectrophotometric titration
Abstract Carrageenan is a seaweed polysaccharide widely used as a food gelling and thickening agent. The New Methylene Blue dye was tested as an analytical reagent for the quantification of carrageenan in commercial jelly samples. The main spectral peaks of the dye decrease with increasing carrageenan-to-dye molar ratio up to 1. Three analytical procedures w
Food Sci. Technol. Publicado em: 2021-06
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15. New Pair of 2-Amino-naphthoxazoles Derived from β-Lapachone: Synthesis, Spectral Evaluation and Crystal Structure
This work describes a novel synthetic route for obtaining 2-amino-naphthoxazoles derived from β-lapachone, which consists of a condensation reaction between β-lapachone and thiourea in a basic medium. This synthetic approach can be seen as a potential route for obtaining 2-amino-oxazoles from quinones. The obtained amino-naphthoxazoles were characterized b
J. Braz. Chem. Soc.. Publicado em: 2021-05
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16. ATR-FTIR FOR CHARACTERIZING AND DIFFERENTIATING DRIED AND GROUND COFFEE CHERRY PULP OF DIFFERENT VARIETIES (Coffea Arabica L.)
ABSTRACT This study aimed to evaluate the performance of the infrared spectrum in the range of 4000−650 cm−1 for characterizing and differentiating dried and ground coffee cherry pulp of different varieties. The spectral data were subjected to first and second derivative treatments to perform the statistical analyses. Three varieties of coffee pulp were
Eng. Agríc.. Publicado em: 2021-02
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17. Evaluation of Auditory Stream Segregation in Musicians and Nonmusicians
Abstract Introduction One of the major cues that help in auditory stream segregation is spectral profiling. Musicians are trained to perceive a fine structural variation in the acoustic stimuli and have enhanced temporal perception and speech perception in noise. Objective To analyze the differences in spectral profile thresholds in musicians and nonmusic
Int. Arch. Otorhinolaryngol.. Publicado em: 2021-01
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18. Evaluation of the Metabolic Profile of Arabica Coffee via NMR in Relation to the Time and Temperature of the Roasting Procedure
Coffee is one of the most popular and consumed products in the world, with high nutritional value and economic importance. However, some factors can change the organoleptic properties of a coffee species, without causing significant damage such as loss of important components. The present study evaluated the chemical profile, via nuclear magnetic resonance (
J. Braz. Chem. Soc.. Publicado em: 2021-01
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19. EVALUATION OF THE RADIOMETRIC ACCURACY OF IMAGES OBTAINED BY A SEQUOIA MULTISPECTRAL CAMERA
ABSTRACT Geometric and radiometric corrections of images obtained by remotely piloted aircraft systems (RPAS) are required for the measurement of the spectral reflectance and calculation of vegetation indices. This study aimed to determine which radiometric calibration procedures allow obtaining suborbital images with more accurate reflectance data and spect
Eng. Agríc.. Publicado em: 2020-12
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20. X-ray Scattering and Chemometrics as Tools to Assist in the Identification of Gunshot Residues by Wavelength Dispersive X-ray Fluorescence Spectrometry
Wavelength dispersion X-ray fluorescence spectrometry (WDXRF) is a non-destructive technique and therefore attractive for gunshot residues (GSR) analysis. It is well known for determination of inorganic constituents of samples. However, X-ray scattering region spectral data is not commonly used, although it may provide information about organic constituents
J. Braz. Chem. Soc.. Publicado em: 2020-12
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21. AUTENTICAÇÃO DE ORÉGANO (Origanum vulgare L.) ORGÂNICO UTILIZANDO ESPECTROSCOPIA NIR E QUIMIOMETRIA
In recent years, the consumption of organic foods has considerably increased. The basic difference between organic and non-organic food products is the way in which they are produced and processed, and the authenticity of these products is a current trend in food science and analytical chemistry. In this sense, the objective of this work was to propose an an
Quím. Nova. Publicado em: 2020-12
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22. MÉTODO MANUAL PARA DEPOSIÇÃO DE TINTAS FOTOLUMINESCENTES BASEADAS EM LOFS MISTAS APLICADO A CODIFICAÇÃO DE DOCUMENTOS
In this work, the process of synthesis of Metal-Organic Frameworks containing lanthanide ions (LOFs), accelerated via a precipitating agent, capable of accelerating the process of nucleation of MOF crystals, in order to explore the optical properties of this precursor solution (SP_Gd/EU-MOF), as a quick-response photoluminescent material in the coding of off
Quím. Nova. Publicado em: 2020-12
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23. Sunlight-Driven Dehydrogenative Oxidation Photocatalysis by a Mononuclear Complex Acting as both Chromophore and Catalyst
Under simulated solar irradiation in the visible spectral region, the catalytically active RuIV-oxo species [Ru(O)(bpy)(tppz)]2+ (tppz = tetrapyridylpyrazine, a strongly π-accepting tridentate N, N, N-ligand) is produced directly from a single metal-to-ligand charge-transfer (MLCT) photoexcitation of the resting RuII-aquo complex [Ru(H2O)(bpy)(tppz)]2+ in a
J. Braz. Chem. Soc.. Publicado em: 2020-11
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24. Pesquisa em doenças inflamatórias intestinais no Brasil: um passo à frente rumo ao cuidado dos pacientes
Maytenus distichophylla is a medicinal species used in Northeast of Brazil. The hexane (HE), chloroform (CE), ethyl acetate (EAE) and methanol (ME) extracts and compounds from its roots were evaluated for their protective activity against Staphylococcus aureus and Candida albicans. The cytotoxicity for chronic myeloid leukemia (K562), acute monocytic leukemi
Arq. Gastroenterol.. Publicado em: 2020-09