Bleaching effectiveness and cytotoxicity of new experimental formulation of niobium-based bleaching gel.

Objectives: The development of new bleaching agents with minimum concentration of hydrogen peroxide (HP), without adverse effects, and with bleaching effectiveness, has great clinical relevance. The aim of this study was to evaluate the bleaching efficacy and cytotoxicity of a new niobium-based bleaching gel, compared to already available HP-based gels.

Materials And Methods: For the bleaching efficacy analysis, 40 bovine incisors were randomly divided into 4 groups according to the established bleaching protocol: control, untreated; 35HP, 35% HP bleaching gel; 6HP, 6% HP bleaching gel; NbHP, niobium gel associated with 3% HP gel.

Effect of pH, ionic strength, and temperature on the adsorption behavior of Acid Blue 113 onto mesoporous carbon.

Mesoporous carbon (MC) derived from cassava starch was used to remove Acid Blue 113 azo dye from aqueous solutions. The influence of temperature, pH, ionic strength, and the adsorbent dose was investigated in a set of batch experiments. Experimental data showed that Acid Blue 113 adsorption was higher in the acid pH range than in the alkaline one, that dye adsorption increases when the ionic strength and temperature increase, and that adsorption results presented a good correlation with the Langmuir isotherm model.

Magnetic photocatalysts from δ-FeOOH and TiO and application in reactions for degradation of methylene blue and paracetamol with UV-C and sunlight.

Water contamination is a common problem, especially considering dyes and drugs disposal. A possible and effective treatment method to remove these organic pollutants from water is photocatalytic reaction. This study aimed to improve the photocatalytic properties of TiO using iron oxides (Ti/Fe composite).

Use of iron ore tailing from tailing dam as catalyst in a fenton-like process for methylene blue oxidation in continuous flow mode.

The global demand for iron ore with high iron contents to supply the steel industry is associated, in most countries, with the generation of tailings from mineral processing. The chemical compositions of iron ore tailings (basically FeO and SiO) make them an excellent candidate as a catalyst for advanced oxidation processes (AOPs), especially the Fenton process and its derivatives. Therefore, this paper aimed to transform iron ore tailings from tailing dams into catalysts able to activate HO for the purpose of treating, in a continuous flow, effluents contaminated with organic dyes, employing methylene blue as a model molecule.

Bioengineered carboxymethyl cellulose-doxorubicin prodrug hydrogels for topical chemotherapy of melanoma skin cancer.

Melanoma is the most aggressive type of skin cancer with high rates of mortality. Despite encouraging advances demonstrated by anticancer drug carriers in recent years, developing ideal drug delivery systems to target tumor microenvironment by overcoming physiological barriers and chemotherapy side effects still remain intimidating challenges. Herein, we designed and developed a novel carbohydrate-based prodrug composed of carboxymethylcellulose (CMC) polymer bioconjugated with anticancer drug doxorubicin hydrochloride (DOX) by covalent amide bonds and crosslinked with citric acid for producing advanced hydrogels.

Activated carbon prepared from coffee pulp: potential adsorbent of organic contaminants in aqueous solution.

The processing of coffee beans generates large amounts of solid and liquid residues. The solid residues (pulp, husk and parchment) represent a serious environmental problem and do not have an adequate disposal mechanism. In this work, activated carbons (ACs) for adsorption of organic compounds were prepared from coffee pulp by controlled temperature at different pulp/Na2HPO4 ratios (4:1, 2:1, 5:4 and 1:1).

Controlling the morphology and pore size of mesostructured silica nanoparticles: the role of the iron oxidation state.

We demonstrate morphology and pore size dependence of silica nanoparticles (SNPs) synthesized via control of the iron oxidation state. In the absence of any Fe species, only spherical SNPs are produced, whereas in the presence of Fe³⁺ and Fe²⁺ ions, SNPs with rod-like and nanosheet morphologies, respectively, are formed. The average pore size increases from 1.

A friendly environmental material: iron oxide dispersed over activated carbon from coffee husk for organic pollutants removal.

A friendly environmental material for organic contaminants removal was prepared in this work: small particles of iron oxide dispersed over activated carbon from coffee waste for Fenton-like application. The materials were characterized by means of XRD, N2 physisorption, Mössbauer spectroscopy and H2 pulse titration. The composites showed very good catalytic performances for methylene blue organic dye oxidation.