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Juanjuan Gao, Jingkun Fang, Xuehai Ju, Weiqing Zhu, Xuezhen Lin, Shupeng Zhang, Chuang Ma, Haiou Song
An electrochemically active sensing nanomaterial (denoted as CD-MPEA-NG) has been successfully constructed by an hierarchical self-assembly of cyclodextrin (CD) and N, N-dimethyl-4-(phenylethynyl)aniline (MPEA) on N-doped graphene (NG) in a low-temperature hydrothermal process. The unique nanostructure of the high-performance CD-MPEA-NG was confirmed by utilizing the Fourier transform infrared spectra, an X-ray diffractometer, a differential pulse voltammetry (DPV), etc. In particular, the method of density functional theory with dispersion energy (DFT-D) of wB97XD/LanL2DZ was employed to optimize and describe the face-to-face packing structure of heterodimers of NG and MPEA...
October 16, 2017: ACS Applied Materials & Interfaces
Vinh X Truong, Fanyi Li, Francesca Ercole, John S Forsythe
We introduce a click and visible-light triggered unclick approach via thio-bromo reaction and hydroquinone photoreduction/trimethyl lock cleavage for polymer modifications. Both reactions can be carried out in water and at ambient temperature, enabling preparation of bioorthogonal hydrogels for encapsulation and controlled release of various cells.
October 16, 2017: Chemical Communications: Chem Comm
Nasrin Saki, Mohammad Darayesh, Alireza Heiran
INTRODUCTION: Melasma is a benign, acquired, and chronic hypermelanosis. Topical hydroquinone (HQ) is a conventional choice to treat melasma. Tranexamic acid (TA) is a relatively new brightening agent that interferes with keratinocyte- melanocyte interactions. The aim of the present study was to compare the efficacy and safety of TA intradermal injections with HQ in treating melasma. MATERIALS AND METHODS: In this split-face controlled trial, thirty-seven patients were randomized to receive three monthly sessions of TA intradermal injections either on the right or the left side of their face, and topical HQ once a night for three months on the other side...
October 13, 2017: Journal of Dermatological Treatment
Dandan Chen, Xin Li, Xiaoyun Liu, Xiaoyu Liu, Xiuying Jiang, Juan Du, Qian Wang, Yuanjing Liang, Wei Ma
NRH: quinone oxidoreductase 2 (NQO2) is a cytosolic and ubiquitously expressed flavoprotein that catalyzes the two-electron reduction of quinone to hydroquinones. Herein, we assessed the protein expression, subcellular localization and possible functions of NQO2 in mouse oocyte meiotic maturation and embryo development. Western blot analysis detected high and stable protein expression of NQO2 in mouse oocytes during meiotic progression. Immunofluorescence illustrated NQO2 distribution on nuclear membrane, chromosomes and meiotic spindles...
September 4, 2017: Biology of Reproduction
Thep Chalermchai, Paisal Rummaneethorn
BACKGROUND: Picosecond laser is a novel modality for pigmented skin disorders with extremely short pulse duration. Little is known about the effects of picosecond laser in melasma. OBJECTIVE: This study aimed to investigate the efficacy of fractional picosecond 1,064 nm laser in melasma treatment. STUDY DESIGN: A prospective, randomized, assessor-blinded, intra-individual split face comparative study. METHODS: Female subjects with melasma were enrolled and received fractional picosecond 1,064 nm laser plus 4% hydroquinone cream on one randomly-assigned side of the face; results were compared to use of hydroquinone cream only on the contralateral side...
October 11, 2017: Journal of Cosmetic and Laser Therapy: Official Publication of the European Society for Laser Dermatology
DongShuai Bao, Meishan Wang, Chuanlu Yang, Yunfan Yang, Xiaoguang Ma
The concerted mechanisms of excited state intramolecular proton transfer (ESIPT) of bis-2, 4-(2-benzoxazolyl)-hydroquinone (BBHQ') and its derivatives (BBHQ'- and DHBO') have been investigated using the density functional theory (DFT) and the time-dependent density functional theory (TDDFT). The calculated absorption and emission spectra of BBHQ' and its derivatives are in good agreement with the experimental results. The calculated bond lengths, bond angles and IR vibrational spectra linked with hydrogen bond of molecular BBHQ' in the S0 and S1 states demonstrate that the hydrogen bond is strengthened in the S1 state...
October 10, 2017: Journal of Physical Chemistry. A
Ludovic Troian-Gautier, Epiphanie Mugeniwabagara, Luca Fusaro, Emilie Cauët, Andrée Kirsch-De Mesmaeker, Michel Luhmer
The excited-state quenching of [Ru(TAP)2(HAT)](2+) (TAP = 1,4,5,8-tetraazaphenanthrene, HAT= 1,4,5,8,9,12-hexaazatriphenylene) by hydroquinone (H2Q), N-acetyl-tyrosine (N-Ac-Tyr) or guanosine-5'-monophosphate (GMP) was investigated at various pH values. The quenching occurs via electron/proton transfer, as evidenced by transient absorption spectroscopy and confirmed by (1)H photochemically induced dynamic nuclear polarization (photo-CIDNP). Reductive quenching also occurs in strongly acidic solution despite a much shorter lifetime of the protonated excited-state complex...
October 11, 2017: Journal of the American Chemical Society
Jiaxian Liu, Qian Yuan, Xiaoxuan Ling, Qiang Tan, Hairong Liang, Jialong Chen, Lianzai Lin, Yongmei Xiao, Wen Chen, Linhua Liu, Huanwen Tang
Hydroquinone (HQ), a major reactive metabolite of benzene, contributes to benzene‑induced leukemia. The molecular mechanisms that underlie this activity remain to be elucidated. Poly ADP‑ribosylation (PARylation) is a type of reversible posttranslational modification that is performed by enzymes in the PAR polymerase (PARP) family and mediates different biological processes, including apoptosis. Zona occludens 2 (ZO‑2) is a tight junction scaffold protein, which is involved in cell proliferation and apoptosis...
September 27, 2017: Molecular Medicine Reports
Taru Garg, Soumya Agarwal, Shiwangi Rana, Ram Chander
BACKGROUND: Footwear dermatitis represents a common but often undiagnosed or misdiagnosed condition. Patch testing aids in its confirmation and identification of the offending allergen. AIMS: This study aimed to find the frequency of positive patch test reactions in cases with suspected allergic contact dermatitis (ACD) to footwear, as well as the common responsible allergens. MATERIALS AND METHODS: This is a retrospective record based study of 37 patients, with suspected ACD to footwear, who underwent patch testing with Indian standard series and Indian footwear series from July 2012 to July 2015...
September 2017: Indian Dermatology Online Journal
Hiroki Tsujinaka, Asako Itaya-Hironaka, Akiyo Yamauchi, Sumiyo Sakuramoto-Tsuchida, Ryogo Shobatake, Mai Makino, Naonori Masuda, Hiromasa Hirai, Shin Takasawa, Nahoko Ogata
AIMS: Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, possess pleiotropic effects that have been extended to modulation of various cellular behaviors. This study aimed to examine whether statins modulate vascular endothelial growth factor A (VEGF-A) expression in human retinal pigment epithelium (RPE) cells. MAIN METHODS: Human RPE cells (h1RPE7), damaged by hydroquinone (HQ) + advanced glycation endproducts (AGE) in an in vitro AMD model, were treated with atorvastatin or lovastatin for 24 h...
September 2017: Heliyon
José Luiz Sousa, André Aguiar
The influence of diverse aromatic additives on Fenton processes (Fe(2+)/H2O2, Fe(3+)/H2O2) has been evaluated by using the Bismarck Brown Y (BBY) di azo dye as target pollutant. Results indicate that all tested Fe(3+)-reducing additives (gallic, 3,4-dihydroxyphenylacetic, 2,3-dihydroxybenzoic, and 2,5-dihydroxybenzoic acids, catechol, and hydroquinone) exhibited pro-oxidant properties during BBY dye color removal, mainly during Fe(3+)/H2O2 treatments. For example, in the presence of hydroquinone BBY color removal was increased from 22 to 83% for 60 min through the Fe(3+)/H2O2 process...
September 29, 2017: Environmental Science and Pollution Research International
Mohamed Tarek Moustafa, Claudio Ramirez, Kevin Schneider, Shari R Atilano, Gloria Astrid Limb, Baruch D Kuppermann, Maria Cristina Kenney
PURPOSE: Memantine (MEM) acts on the glutamatergic system by blocking N-methyl-d-aspartate (NMDA) glutamate receptors. The role that MEM plays in protecting retinal cells is unknown. Hydroquinone (HQ) is one of the cytotoxic components in cigarette smoke. In the present study, we tested whether pretreatment with MEM could protect against the cytotoxic effects of HQ on human retinal pigment epithelium cells (ARPE-19) and human retinal Müller cells (MIO-M1) in vitro. METHODS: Cells were plated, pretreated for 6 h with 30 μM of MEM, and then exposed for 24 h to 200, 100, 50, and 25 μM of HQ while MEM was still present...
October 2017: Journal of Ocular Pharmacology and Therapeutics
Jin-Pei Wang, Wen-Mao Zhang, Hong-Jun Chao, Ning-Yi Zhou
A LysR-type transcriptional regulator (LTTR), PnpR, has previously been shown to activate the transcription of operons pnpA, pnpB, and pnpCDEFG for para-nitrophenol (PNP) degradation in Pseudomonas sp. strain WBC-3. Further preliminary evidence suggested the possible presence of an LTTR additional binding site in the promoter region of pnpCDEFG. In this study, an additional LTTR PnpM, which shows 44% homology to PnpR, was determined to activate the expression of pnpCDEFG. Interestingly, a pnpM-deleted WBC-3 strain was unable to grow on PNP but accumulating hydroquinone (HQ), which is the catabolic product from PNP degradation by PnpAB and the substrate for PnpCD...
2017: Frontiers in Microbiology
Xiaori Fu, Xiaogang Gu, Shuguang Lu, Virender K Sharma, Mark L Brusseau, Yunfei Xue, Muhammad Danish, George Y Fu, Zhaofu Qiu, Qian Sui
Complete degradation of benzene by the Fe(III)-activated sodium percarbonate (SPC) system is demonstrated. Removal of benzene at 1.0 mM was seen within 160 min, depending on the molar ratios of SPC to Fe(III). A mechanism of benzene degradation was elaborated by free-radical probe-compound tests, free-radical scavengers tests, electron paramagnetic resonance (EPR) analysis, and determination of Fe(II) and H2O2 concentrations. The degradation products were also identified using gas chromatography-mass spectrometry method...
February 1, 2017: Chemical Engineering Journal
Alex Frichert, Peter G Jones, Mark Brönstrup, Thomas Lindel
Aiming at the discovery of new cytotoxic meroterpenoids, the chemical reactivity of the natural product (-)-terreumol C from the edible mushroom Tricholoma terreum was investigated. A series of high-yielding oxygenations and brominations at the 10-membered ring were discovered. The regioselectivity of hydroxylation could be guided by installing protecting groups at the hydroquinone section. Dihydroxylation led to the stereoselective formation of a novel tricycle containing an 11-oxabicyclo[5.3.1]undecane system...
September 28, 2017: Journal of Natural Products
Jefferson S Plegaria, Markus Sutter, Bryan Ferlez, Clément Aussignargues, Jens Niklas, Oleg G Poluektov, Ciara Fromwiller, Michaela TerAvest, Lisa Marie Utschig, David Michael Tiede, Cheryl A Kerfeld
Bacterial microcompartments (BMCs) are proteinaceous organelles that encapsulate enzymes involved in CO2 fixation (carboxysomes) or carbon catabolism (metabolosomes). Metabolosomes share a common core of enzymes and a distinct signature enzyme for substrate degradation that defines the function of the BMC (e.g. propanediol or ethanolamine utilization BMCs, or glycyl-radical enzyme microcompartments). Loci encoding metabolosomes also typically contain genes for proteins that support organelle function, such as regulation, transport of substrate, and co-factor (e...
September 28, 2017: Biochemistry
Zidan Yuan, Shaofeng Wang, Xu Ma, Xin Wang, Guoqing Zhang, Yongfeng Jia, Wei Zheng
Scorodite (FeAsO4·2H2O) is an important arsenic-bearing solid waste in hydrometallurgical industries, but its stability in reducing environments is not well understood. This study investigated the effect of Fe(III) reduction by enolic hydroxyl groups on the stability of scorodite and arsenic mobilization at various pH values and ascorbic acid/scorodite molar ratios (AH2/Sc). The results showed that 47-89% Fe(III) reduction by ascorbic acid caused approximately 10-69% (~ 37-260 mg L(-1)) arsenic release and 4...
September 26, 2017: Environmental Science and Pollution Research International
Ying-Xu Chen, Ke-Jing Huang, Liu-Liu He, Yi-Han Wang
A novel competitive aptasensor for thrombin detection is developed by using a tetrahedral DNA (T-DNA) probe and hybridization chain reaction (HCR) signal amplification. Sulfur and nitrogen co-doped reduced graphene oxide (SN-rGO) is firstly prepared by a simple reflux method and used for supporting substrate of biosensor. Then, T-DNA probe is modified on the electrode by Au-S bond and a competition is happened between target thrombin and the complementary DNA (cDNA) of aptamer. The aptamer binding to thrombin forms an aptamer-target conjugate and make the cDNA remained, and subsequently hybridizes with the vertical domain of T-DNA...
September 15, 2017: Biosensors & Bioelectronics
Chaofan Ding, Yue Li, Yanhui Wang, Jianbo Li, Yuanling Sun, Yanna Lin, Weiyan Sun, Chuannan Luo
Magnetic hydroxyethyl cellulose/ionic liquid (MHEC/IL) materials were fabricated through a facile and fast process and their application as excellent adsorbents for hydroquinone was also demonstrated. The thermal stability, chemical structure and magnetic property of the MHEC/IL were characterized by the Scanning electron microscope (SEM), Transmission Electron Microscope (TEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD), respectively. The adsorbents were used for the removal of hydroquinone from simulated wastewater with a fast solid-liquid separation in the presence of external magnetic field...
September 19, 2017: International Journal of Biological Macromolecules
Mingshun Chen, Shujuan Yu
Grape seed proanthocyanidins, composed of flavan-3-ols of different degrees of polymerization, are natural food antioxidants. Flavan-3-ols in grape seed are usually polyhydroxy derivatives which exhibit hydrophilic character. Monomeric and oligomeric flavan-3-ols were modified structurally to improve their lipophilicity, expand their application in lipophilic media, and enhance their cellular absorption in the body. The esterification of the water-soluble flavan-3-ols was prepared by Lipozyme TL IM with lauric acid, and their enhanced lipophilicity was confirmed by a 1-octanol/water partition coefficient...
October 11, 2017: Journal of Agricultural and Food Chemistry
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