Results 61 to 70 of about 27,101 (268)

Determinação simultânea de ácido kójico e hidroquinona por espectrofotometria visível e calibração multivariada

Química Nova, 2011
A multivariate spectrophotometric method was developed for analysis of kojic acid/hydroquinone associations in skin whitening cosmetics. The method is based on the reaction between kojic acid and Fe3+ and on the reduction of Fe3+ by hydroquinone and ...
Giselle Nathaly Calaça, Sandra Stets, Noemi Nagata   +2 more
doaj   +1 more source

Hydroquinone Oxidation by Redox‐active Guanidines and Thioguanidines: Faster Conversion to High‐Potential Than to Low‐Potential Quinones

Chemistry – A European Journal, EarlyView.
New redox‐active oligothioguanidines are developed and used in dehydrogenative P–P coupling reactions and hydroquinone oxidations. Tetrathioguanidino‐ and tetraguanidinobenzenes oxidize high‐potential halogenated hydroquinones faster than relatively low‐potential hydroquinone.
Ute Wild, Olaf Hübner, Sebastian Jaworski, Elisabeth Kaifer, Hans‐Jörg Himmel   +4 more
wiley   +1 more source

A novel fluorescent probe involving a graphene quantum dot-enzyme hybrid system for the analysis of hydroquinone in the presence of toxic resorcinol and catechol

, 2014
An efficient method for the analysis of hydroquinone at trace levels in water samples has been developed in the form of a fluorescent probe based on graphene quantum dots (GQDs).
Li, Zhuo, Kokot, Serge, Sun, Ruiling, Ni, Yongnian   +3 more
core   +1 more source

Unravelling the initiator‐only stage in alginate grafting: Radical‐induced depolymerization and its impact on acrylamide grafting efficiency

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract Free‐radical grafting of natural polymers often assumes that initiators only create active sites before monomer addition. We tested this by exposing sodium alginate to potassium persulphate (KPS) under typical grafting conditions without monomer (acrylamide).
Gustavo P. Zago, João B. P. Soares
wiley   +1 more source

The formation of gold nanoparticles using hydroquinone as a reducing agent through a localized pH change upon addition of NaOH to a solution of HAuCl4

, 2010
We demonstrate a rapid synthesis of gold nanoparticles using hydroquinone as a reducing agent under acidic conditions without the need for precursor seed particles.
Adam Mechler, Alan M. Bond, Sirajuddin., Mechler, Adam, Bond, Alan M., Angel A.J. Torriero, Lee, Chong-Yong, Bhargava, Suresh K., Torriero, Angel A.J., Ayman Nafady, null Sirajuddin, Chong-Yong Lee, Nafady, Ayman, O'Mullane, Anthony P., Anthony P. O’Mullane, Suresh K. Bhargava   +15 more
core   +1 more source

Nrf2 and HSF-1 Pathway Activation via Hydroquinone-Based Proelectrophilic Small Molecules Is Regulated by Electrochemical Oxidation Potential

ASN Neuro, 2015
Activation of the Kelch-like ECH-associated protein 1/nuclear factor (erythroid-derived 2)-like 2 and heat-shock protein 90/heat-shock factor-1 signal-transduction pathways plays a central role in combatting cellular oxidative damage and related ...
Takumi Satoh, Romain Stalder, Scott R. McKercher, Robert E. Williamson, Gregory P. Roth, Stuart A. Lipton   +5 more
doaj   +1 more source

A Nano˗Sepiolite Clay Electrochemical Sensor for the Rapid Electro–Catalytic Detection of Hydroquinone in Cosmetic Products

Acta Chimica Slovenica, 2018
In this paper, a simple and sensitive electrochemical nano-sensor was developed for the analysis of hydroquinone based on sepiolite clay modified carbon paste sensor by using differential pulse adsorptive stripping voltammetry and square wave adsorptive ...
Sevda Aydar, Dilek Eskiköy Bayraktepe, Hayati Filik, Zehra Yazan   +3 more
doaj   +1 more source

Tunable amylopectin graft copolymers for flocculating and dewatering iron ore tailings

The Canadian Journal of Chemical Engineering, EarlyView.
Abstract Polyacrylamide (PAM), the standard flocculant for mining tailings, often produces turbid supernatants and poorly dewatered sediments, limiting water reuse and tailings densification. We synthesized amylopectin‐graft‐poly[(2‐methacryloyloxy)ethyl]trimethylammonium chloride (AP‐g‐PMETAC) copolymers with systematically varied graft frequency (N = 
Gustavo P. Zago, Reinaldo Giudici, João B. P. Soares   +2 more
wiley   +1 more source

Mit Oliven zur Batterie – Experimente zu Batterien mit unerwarteten Zutaten

CHEMKON, EarlyView.
Der Umstieg auf erneuerbare Energien erfordert neue Speicherlösungen. Besonders im Fokus stehen dabei die Energiespeicherung aus regenerativen Energietechniken wie Solar‐ und Windkraft. Auch hinsichtlich der Speichertechnologie soll auf Nachhaltigkeit gesetzt werden, um eine sichere und umweltschonende Energiespeicherung zu ermöglichen.
Dominique Rosenberg, Tom Severin Gabriel
wiley   +1 more source

ntimelanogenesis effect of ethyl acetate extract of avocado seeds (Persea americana Mill.) on B16F10 melanoma cells [PDF]

Journal of Pharmacy & Pharmacognosy Research
Context: Hyperpigmentation is frequently associated with ultraviolet radiation exposure. Natural tyrosinase inhibitors, such as catechin from avocado seeds (Persea americana Mill.), are increasingly studied due to their antioxidant and tyrosinase ...
Shalina Sebayang, Raendi Rayendra, Ietje Wientarsih, Bambang Pontjo Priosoeryanto   +3 more
doaj   +1 more source