keyword
MENU ▼
Read by QxMD icon Read
search

Oxylator

keyword
https://www.readbyqxmd.com/read/28322007/one-electron-initiated-two-electron-oxidation-of-water-by-aluminum-porphyrins-with-earth-s-most-abundant-metal-ion
#1
Fazalurahman Kuttassery, Siby Mathew, Shogo Sagawa, Sebastian Nybin Remello, Arun Thomas, Daisuke Yamamoto, Satomi Onuki, Yu Nabetani, Hiroshi Tachibana, Haruo Inoue
We report here a new molecular catalyst for efficient water splitting, aluminum porphyrins (tetra-methylpyridiniumylporphyrinatealuminum: AlTMPyP), containing the Earth's most abundant metal as the central ion. One-electron oxidation of the aluminum porphyrin initiates the two-electron oxidation of water to form hydrogen peroxide as the primary reaction product with the lowest known overpotential (97 mV). The aluminum-peroxo complex was clearly detected by a cold-spray ionization mass-spectrometry in HRMS mode and the structure of the intermediate was further confirmed using laser-Raman spectroscopy, indicating the hydroperoxy complex of AlTMPyP to be the key intermediate in the reaction...
March 20, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28287515/a-protocol-for-electrochemical-evaluations-and-state-of-charge-diagnostics-of-a-symmetric-organic-redox-flow-battery
#2
Wentao Duan, Rama S Vemuri, Dehong Hu, Zheng Yang, Xiaoliang Wei
Redox flow batteries have been considered as one of the most promising stationary energy storage solutions for improving the reliability of the power grid and deployment of renewable energy technologies. Among the many flow battery chemistries, non-aqueous flow batteries have the potential to achieve high energy density because of the broad voltage windows of non-aqueous electrolytes. However, significant technical hurdles exist currently limiting non-aqueous flow batteries to demonstrate their full potential, such as low redox concentrations, low operating currents, under-explored battery status monitoring, etc...
February 13, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28267498/lignocellulosic-nanofibers-from-triticale-straw-the-influence-of-hemicelluloses-and-lignin-in-their-production-and-properties
#3
Quim Tarrés, Nanci Vanesa Ehman, María Evangelina Vallejos, Maria Cristina Area, Marc Delgado-Aguilar, Pere Mutjé
The present work aims to determine the influence of hemicellulose and lignin content in the production of lignocellulosic nanofibers (LCNF) from triticale straws. Triticale straws were digested and then gradually delignified, preserving as much hemicelluloses as possible. The obtained LCNF was characterized and used as paper strength additive, observing that hemicellulose and lignin have a key role on the final properties thereof, as well as on their reinforcing potential as paper additive, obtaining LCNF with the same paper reinforcing potential than CNF obtained by TEMPO ((2,2,6,6-Tetramethyl-piperidin-1-yl)oxyl) mediated oxidation...
May 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28257840/non-invasive-imaging-of-the-levels-and-effects-of-glutathione-on-the-redox-status-of-mouse-brain-using-electron-paramagnetic-resonance-imaging
#4
Miho C Emoto, Yuta Matsuoka, Ken-Ichi Yamada, Hideo Sato-Akaba, Hirotada G Fujii
Glutathione (GSH) is the most abundant non-protein thiol that buffers reactive oxygen species in the brain. GSH does not reduce nitroxides directly, but in the presence of ascorbates, addition of GSH increases ascorbate-induced reduction of nitroxides. In this study, we used electron paramagnetic resonance (EPR) imaging and the nitroxide imaging probe, 3-methoxycarbonyl-2,2,5,5-tetramethyl-piperidine-1-oxyl (MCP), to non-invasively obtain spatially resolved redox data from mouse brains depleted of GSH with diethyl maleate compared to control...
April 15, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28257189/the-role-of-the-secondary-coordination-sphere-in-a-fungal-polysaccharide-monooxygenase
#5
Elise A Span, Daniel L M Suess, Marc C Deller, R David Britt, Michael A Marletta
Polysaccharide monooxygenases (PMOs) are secreted metalloenzymes that catalyze the oxidative degradation of polysaccharides in a copper-, oxygen-, and reductant-dependent manner. Cellulose-active fungal PMOs degrade cellulosic substrates to be utilized as a carbon source for fungal growth. To gain insight into the PMO mechanism, the role of conserved residues in the copper coordination sphere was investigated. Here, we report active-site hydrogen-bonding motifs in the secondary copper coordination sphere of MtPMO3*, a C1-oxidizing PMO from the ascomycete fungus Myceliophthora thermophila...
March 3, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28246040/degradation-of-contaminants-by-cu-activated-molecular-oxygen-in-aqueous-solutions-evidence-for-cupryl-species-cu-3
#6
Yong Feng, Po-Heng Lee, Deli Wu, Zhengyuan Zhou, Hangkong Li, Kaimin Shih
Copper ions (Cu(2+) and Cu(+)) have shown potential as Fenton-like activators for the circumneutral removal of organic contaminants from aqueous solutions. However, the major active species (cupryl species (Cu(3+)) versus hydroxyl radical (OH)) produced during the activation of hydrogen peroxide by Cu(+) remain unclear. In this study, Cu(+)-O2 oxidation, in which hydrogen peroxide is produced via the activated decomposition of dissolved molecular oxygen, was used to degrade sulfadiazine, methylene blue, and benzoic acid...
February 20, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28240552/ikmtsl-pte-a-phospholipid-based-epr-probe-for-surface-electrostatic-potential-of-biological-interfaces-at-neutral-ph-effects-of-temperature-and-effective-dielectric-constant-of-the-solvent
#7
Maxim A Voinov, Christina T Scheid, Igor A Kirilyuk, Dmitrii G Trofimov, Alex I Smirnov
The synthesis and characterization of a lipidlike electrostatic spin probe, (S)-2,3-bis(palmitoyloxy)propyl 2-((4-(4-(dimethylamino)-2-ethyl-1-oxyl-5,5-dimethyl-2,5-dihydro-1H-imidazol-2-yl)benzyl)disulfanyl)ethyl phosphate (IKMTSL-PTE), are being reported. The intrinsic pKa(0) of IKMTSL-PTE was determined by X-band (9.5 GHz) electron paramagnetic resonance (EPR) titration of a water-soluble model compound, 4-(dimethylamino)-2-ethyl-2-(4-(((2-hydroxyethyl)disulfanyl)methyl)phenyl)-5,5-dimethyl-2,5-dihydro-1H-imidazol-1-oxyl (IKMTSL-ME), an adduct of methanethiosulfonate spin label IKMTSL and 2-mercaptoethanol...
March 10, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28238951/oral-administration-of-the-nitroxide-radical-tempol-exhibits-immunomodulatory-and-therapeutic-properties-in-multiple-sclerosis-models
#8
Sarah Neil, Jaebong Huh, Victoria Baronas, Xinhui Li, Henry F McFarland, Murali Cherukuri, James B Mitchell, Jacqueline A Quandt
Therapies with both immunomodulatory and neuroprotective properties are thought to have the greatest promise in reducing the severity and progression of multiple sclerosis (MS). Several reactive oxygen (ROS) and reactive nitrogen species (RNS) are implicated in inflammatory-mediated damage to the central nervous system (CNS) in MS and its animal model, experimental autoimmune encephalomyelitis (EAE). TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl) is a stable nitroxide radical with potent antioxidant activity...
February 23, 2017: Brain, Behavior, and Immunity
https://www.readbyqxmd.com/read/28220127/nitric-oxide-ameliorates-zinc-oxide-nanoparticles-phytotoxicity-in-wheat-seedlings-implication-of-the-ascorbate-glutathione-cycle
#9
Durgesh K Tripathi, Rohit K Mishra, Swati Singh, Samiksha Singh, Kanchan Vishwakarma, Shivesh Sharma, Vijay P Singh, Prashant K Singh, Sheo M Prasad, Nawal K Dubey, Avinash C Pandey, Shivendra Sahi, Devendra K Chauhan
The present study investigates ameliorative effects of nitric oxide (NO) against zinc oxide nanoparticles (ZnONPs) phytotoxicity in wheat seedlings. ZnONPs exposure hampered growth of wheat seedlings, which coincided with reduced photosynthetic efficiency (Fv/Fm and qP), due to increased accumulation of zinc (Zn) in xylem and phloem saps. However, SNP supplementation partially mitigated the ZnONPs-mediated toxicity through the modulation of photosynthetic activity and Zn accumulation in xylem and phloem saps...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28212027/ferromagnetic-coupling-in-the-heterospin-bis-catecholato-manganese-iv-complex-with-pyridine-substituted-by-nitronyl-nitroxide
#10
Michael P Bubnov, Irina A Teplova, Eugenia A Kopylova, Konstantin A Kozhanov, Artem S Bogomyakov, Marina V Petrova, Vitaly A Morozov, Victor I Ovcharenko, Vladimir K Cherkasov
A new bis(3,6-di-tert-butyl-catecholato)manganese complex with two 4-NIT-Py ligands was synthesized and characterized [4-NIT-Py = pyridine substituted at position 4 with nitronyl-nitroxide radical, 2-(pyridin-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl]. X-ray diffraction indicated an octahedral environment of the manganese atom with a trans arrangement of ligands. Bonds lengths in the inner coordination core of the metal and in the chelate cycles that are representative of the charge distribution between the metal and ligands displayed a Mn(IV)(Cat(2-))2 charge distribution...
February 17, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28210984/effect-of-solution-ionic-strength-on-the-pka-of-the-nitroxide-ph-epr-probe-2-2-3-4-5-5-hexamethylimidazolidin-1-oxyl
#11
Kaleigh Margita, Maxim A Voinov, Alex I Smirnov
Spin probe and spin labeling Electron Paramagnetic Resonance methods are indispensable research tools for solving a wide range of bioanalytical problems-from measuring microviscosity and polarity of phase-separated liquids to oxygen concentrations in tissues. One of the emerging uses of spin probes are the studies of proton transfer-related and surface electrostatic phenomena. The latter Electron Paramagnetic Resonance methods rely on molecular probes containing an additional functionality capable of reversible ionization (protonation, in particular) in the immediate proximity to an Electron Paramagnetic Resonance-active reporter group, such as (N-O(•)) for nitroxides...
February 17, 2017: Cell Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28210728/self-initiation-of-uv-photopolymerization-reactions-using-tetrahalogenated-bisphenol-a-meth-acrylates
#12
Théophile Pelras, Wolfgang Knolle, Sergej Naumov, Katja Heymann, Olesya Daikos, Tom Scherzer
The potential of tetrachlorinated and tetrabrominated bisphenol A diacrylates and dimethacrylates for self-initiation of a radical photopolymerization was investigated. The kinetics of the photopolymerization of an acrylic model varnish containing halogenated monomers was studied by real-time FTIR spectroscopy, whereas the formation of reactive species and secondary products was elucidated by laser flash photolysis and product analysis by GC-MS after steady-state photolysis. The interpretation of the experimental data and the analysis of possible reaction pathways were assisted by quantum chemical calculations...
February 17, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28195581/cultivation-and-characterization-of-candidatus-nitrosocosmicus-exaquare-an-ammonia-oxidizing-archaeon-from-a-municipal-wastewater-treatment-system
#13
Laura A Sauder, Mads Albertsen, Katja Engel, Jasmin Schwarz, Per H Nielsen, Michael Wagner, Josh D Neufeld
Thaumarchaeota have been detected in several industrial and municipal wastewater treatment plants (WWTPs), despite the fact that ammonia-oxidizing archaea (AOA) are thought to be adapted to low ammonia environments. However, the activity, physiology and metabolism of WWTP-associated AOA remain poorly understood. We report the cultivation and complete genome sequence of Candidatus Nitrosocosmicus exaquare, a novel AOA representative from a municipal WWTP in Guelph, Ontario (Canada). In enrichment culture, Ca...
February 14, 2017: ISME Journal
https://www.readbyqxmd.com/read/28150497/characterization-of-nanocellulose-using-small-angle-neutron-x-ray-and-dynamic-light-scattering-techniques
#14
Yimin Mao, Kai Liu, Chengbo Zhan, Lihong Geng, Benjamin Chu, Benjamin S Hsiao
Nanocellulose extracted from wood pulps using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and sulfuric acid hydrolysis methods was characterized by small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and dynamic light scattering (DLS) techniques. The dimensions of this nanocellulose (TEMPO-oxidized cellulose nanofiber (TOCN) and sulfuric acid hydrolyzed cellulose nanocrystal (SACN)) revealed by the different scattering methods were compared with those characterized by transmission electron microscopy (TEM)...
February 2, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28115098/tempo-oxidized-bacterial-cellulose-nanofibers-supported-gold-nanoparticles-with-superior-catalytic-properties
#15
Yan Chen, Shiyan Chen, Baoxiu Wang, Jingjing Yao, Huaping Wang
A novel nanohybrid was successfully fabricated by deposition of gold nanoparticles (AuNPs) onto the surface of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized bacterial cellulose nanofibers (TOBCNs). The prepared AuNPs/TOBCNs nanohybrids were characterized by UV-vis spectral analysis, XRD, TEM and HRTEM. Their catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) was estimated by UV-vis spectrometry. The results showed that the AuNPs/TOBCNs nanohybrids possessed AuNPs with an average diameter of 4...
March 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28095321/cellulose-to-depolymerize%C3%A2-or-not-to
#16
REVIEW
Sergiu Coseri
Oxidation of the primary OH groups in cellulose is a pivotal reaction both at lab and industrial scale, leading to the value-added products, i.e. oxidized cellulose which have tremendous applications in medicine, pharmacy and hi-tech industry. Moreover, the introduction of carboxyl moieties creates prerequisites for further cellulose functionalization through covalent attachment or electrostatic interactions, being an essential achievement designed to boost the area of cellulose-based nanomaterials fabrication...
March 2017: Biotechnology Advances
https://www.readbyqxmd.com/read/28069660/antioxidant-treatment-attenuates-lactate-production-in-diabetic-nephropathy
#17
Christoffer Laustsen, Per Mose Nielsen, Thomas Stokholm Nørlinger, Haiyun Qi, Uffe Kjærgaard Pedersen, Lotte Bonde Bertelsen, Jakob Appel Østergaard, Allan Flyvbjerg, Jan Henrik Ardenkjær-Larsen, Fredrik Palm, Hans Stødkilde-Jørgensen
The early progression of diabetic nephropathy is notoriously difficult to detect and quantify before the occurrence of substantial histological damage. Recently, hyperpolarized [1-(13)C]pyruvate has demonstrated increased lactate production in the kidney early after the onset of diabetes, implying increased lactate dehydrogenase activity as a consequence of increased nicotinamide adenine dinucleotide substrate availability due to upregulation of the polyol pathway, i.e., pseudohypoxia. In this study, we investigated the role of oxidative stress in mediating these metabolic alterations using state-of-the-art hyperpolarized magnetic resonance (MR) imaging...
January 1, 2017: American Journal of Physiology. Renal Physiology
https://www.readbyqxmd.com/read/28064177/nitric-oxide-acts-upstream-of-ethylene-in-cell-wall-phosphorus-reutilization-in-phosphorus-deficient-rice
#18
Xiao Fang Zhu, Chun Quan Zhu, Chao Wang, Xiao Ying Dong, Ren Fang Shen
Nitric oxide (NO) and ethylene are both involved in cell wall phosphorus (P) reutilization in P-deficient rice; however, the crosstalk between them remains unclear. In the present study using P-deficient 'Nipponbare' (Nip), root NO accumulation significantly increased after 1 h and reached a maximum at 3 h, while ethylene production significantly increased after 3 h and reached a maximum at 6 h, indicating NO responded more quickly than ethylene. Irrespective of P status, addition of the NO donor sodium nitroprusside (SNP) significantly increased while the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) significantly decreased the production of ethylene, while neither the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) nor the ethylene inhibitor aminoethoxyvinylglycine (AVG) had any influence on NO accumulation, suggesting NO acted upstream of ethylene...
January 7, 2017: Journal of Experimental Botany
https://www.readbyqxmd.com/read/28063096/feasibility-of-in-vivo-three-dimensional-t-2-mapping-using-dicarboxy-proxyl-and-cw-epr-based-single-point-imaging
#19
Harue Kubota, Denis A Komarov, Hironobu Yasui, Shingo Matsumoto, Osamu Inanami, Igor A Kirilyuk, Valery V Khramtsov, Hiroshi Hirata
OBJECTIVES: The aim of this study was to demonstrate the feasibility of in vivo three-dimensional (3D) relaxation time T 2(*) mapping of a dicarboxy-PROXYL radical using continuous-wave electron paramagnetic resonance (CW-EPR) imaging. MATERIALS AND METHODS: Isotopically substituted dicarboxy-PROXYL radicals, 3,4-dicarboxy-2,2,5,5-tetra((2)H3)methylpyrrolidin-(3,4-(2)H2)-(1-(15)N)-1-oxyl ((2)H,(15)N-DCP) and 3,4-dicarboxy-2,2,5,5-tetra((2)H3)methylpyrrolidin-(3,4-(2)H2)-1-oxyl ((2)H-DCP), were used in the study...
January 6, 2017: Magma
https://www.readbyqxmd.com/read/28062279/nitric-oxide-induced-synthesis-of-hydrogen-sulfide-alleviates-osmotic-stress-in-wheat-seedlings-through-sustaining-antioxidant-enzymes-osmolyte-accumulation-and-cysteine-homeostasis
#20
M Nasir Khan, M Mobin, Zahid Khorshid Abbas, Manzer H Siddiqui
Nitric oxide (NO) and hydrogen sulfide (H2S) have been shown to act as signaling molecules in various physiological processes, play significant roles in plant cellular processes, and also mediate responses to both biotic and abiotic stresses in plants. The present investigation was carried out to test the effect of exogenous NO on endogenous synthesis of H2S in osmotic-stressed wheat (Triticum aestivum L.) seedlings. The results show that application of NO to wheat seedlings, suffered from PEG8000-induced osmotic stress, considerably enhanced the activities of H2S-synthesizing enzymes l-cysteine desulfhydrase (LCD) and d-cysteine desulfhydrase (DCD) leading to enhanced level of endogenous H2S content...
January 3, 2017: Nitric Oxide: Biology and Chemistry
keyword
keyword
65976
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"