Hydroxyl
Mostrando 1-12 de 1431 artigos, teses e dissertações.
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1. Tuning the Photocatalytic Activity of Tin Oxide through Mechanical Surface Activation
Tin oxide (SnO2) nanoparticles were synthesized by the co-precipitation method and mechanically modified by high-energy ball milling. The experimental results demonstrate that the collision with zirconia balls produces slight changes in the crystalline, electronic, morphological, and surface properties of SnO2, which lead to an increase in the redox potentia
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Enhancement of Visible Light-Responsive Photocatalytic Efficiency by Using a Laccaic Acid-Modified Titanium Dioxide Photocatalyst
In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Antioxidant Properties of Croton zehntneri Pax et Hoffm. Essential Oil and Its Inclusion Complex with β-Cyclodextrin Prepared by Spray Drying
Croton zehntneri Pax et Hoffm. is a plant from Northeastern Brazil, whose main component of its essential oil is estragole. Its thermal instability and low aqueous solubility prevent its technological application. This study aimed to prepare and characterize the Croton zehntneri essential oil (CZEO) complexed with β-cyclodextrin (β-CD), and to evaluate ant
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Challenges of TiO2-composite, as a visible active photocatalyst material for SARS-CoV-2 antiviral compared with the other viruses
The efforts in dealing with COVID-19 in various aspects are continuously being carried out, such as the photocatalytic process. Interestingly, TiO2 plays an important role as an environmentally friendly photocatalyst with a visible and UV absorption range. The increase in the antiviral performance of this compound is further maximized by formulating TiO2-bas
Química Nova. Publicado em: 2022
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5. Fundamental bioflotation aspects of hematite using an extracted Rhodococcus opacus by-product
Abstract The aim of this study is to assess the floatability of hematite using a crude biosurfactant (BS) extracted from Rhodococcus opacus. Throughout high-pressure ethanol extraction, unrefined surfactant was extracted from the bacteria with a yield of 0.3 g/L. An FTIR analysis on this extract, shows the presence of alcohol (–OH) and ketone (C=O) groups,
REM, Int. Eng. J.. Publicado em: 2021-09
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6. Synthesis and characterization of niobium-doped fish scale-derived hydroxyapatite by physical ultrasound interference
Abstract Fish scales of the Arapaima gigas (pirarucu) species were heat-treated to obtain natural hydroxyapatite (HAp), and it was doped with niobium (Nb) by physical ultrasound interference to confirm an effective route to the production of Nb-doped HAp powders. The effect of ultrasound application on doping was investigated. The structure of the powders wa
Cerâmica. Publicado em: 2021-03
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7. HSCCC Separations of Rutin Esters Obtained by Enzymatic Reaction Catalyzed by Lipase
The flavonoid rutin presents several pharmacological effects, despite this, its application in the pharmaceutical industry can be significantly limited by its low bioavailability. The development of lipophilic derivatives by esterification of hydroxyl groups with fatty acid chains may be an effective strategy to change their physicochemical properties. This
J. Braz. Chem. Soc.. Publicado em: 2021-03
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8. Inhibition of Acetylcholinesterase by Coumarin-Linked Amino Acids Synthetized via Triazole Associated with Molecule Partition Coefficient
A previous study for the identification of acetylcholinesterase (AChE) inhibitors demonstrated that the hybrid between tyrosol, the 1,2,3-triazole nucleus, and the coumarin group, namely 7-({1-[2-(4-hydroxyphenyl)ethyl]-1H-1,2,3-triazol-4-yl}methoxy)-4-methyl-2H-chromen-2-one (10), has a high enzyme inhibitory activity. Here, we synthesized analogues of 10 v
J. Braz. Chem. Soc.. Publicado em: 2021-03
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9. 25-Hydroxyl Vitamin D Deficiency in Nasal Polyposis
Abstract Introduction Vitamin D is known to have immunomodulatory functions and has action on chronic inflammatory processes, such as nasal polyposis. Objective The present study assessed the levels of 25-hydroxy vitamin D and high-sensitivity C-reactive protein (hs-CRP) in patients with nasal polyposis, as compared with healthy control subjects, and ident
Int. Arch. Otorhinolaryngol.. Publicado em: 2020-09
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10. A Highly Selective Fluorescent Chemosensor for Al3+ Based on 2,2’:6’,2”-Terpyridine with a Salicylal Schiff Base
Two 2,2’:6’,2”-terpyridine-based Schiff bases (TPySSB and TPySB) have been synthesized. The TPySSB shows remarkable selective ‘off-on’ fluorescence for Al3+ in combination with photoinduced electron transfer (PET) mechanism and C=N isomerization mechanism. Chemosensor TPySSB binds Al3+ in a 1:2 ratio with an association constant 6.8 × 105 (correla
J. Braz. Chem. Soc.. Publicado em: 2020-09
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11. Structural characterization and bioactivities of a polysaccharide from the stalk residue of Pleurotus eryngii
Abstract The structural characterization and bioactivities of a polysaccharide from the stalk residue of Pleurotus eryngii were investigated. Firstly the stalk residue of P. eryngii was collected from the top portion of spent mushroom substrate and processed to yield water-soluble polysaccharide. Subsequently this crude polysaccharide was purified by DEAE Se
Food Sci. Technol. Publicado em: 2020-06
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12. ELECTROCHEMICAL INCINERATION OF SHORT-CHAIN CARBOXYLIC ACIDS WITH NB‑SUPPORTED BORON DOPED DIAMOND ANODE: SUPPORTING ELECTROLYTE EFFECT INTO THE ELECTROGENERATED OXIDANT SPECIES (HYDROXYL RADICALS, HYDROGEN PEROXIDE AND PERSULFATE)
This work describes the electrochemical oxidation study of three short chain carboxylic acids (acetic, oxalic and formic 0.18 mol L-1) using different electrolysis conditions (electrolyte composition and current density) in an electrochemical reactor fitted with niobiumsupported/BDD electrode (Nb/BBD) as anode and titanium plate as cathode. The experiments w
Quím. Nova. Publicado em: 2020-03