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Vivian Midtbø, Guttorm Raknes, Steinar Hunskaar
BACKGROUND: The primary care out-of-hours (OOH) services in Norway are characterized by high contact rates by telephone. The telephone contacts are handled by local emergency medical communication centres (LEMCs), mainly staffed by registered nurses. When assessment by a medical doctor is not required, the nurse often handles the contact solely by nurse telephone counselling. Little is known about this group of contacts. Thus, the aim of this study was to investigate characteristics of encounters with the OOH services that are handled solely by nurse telephone counselling...
September 6, 2017: BMC Family Practice
Nadia Gruber, Liliana R Orelli, Roberto Cipolletti, Pierluigi Stipa
Amidinoquinoxaline N-oxides represent a novel family of heterocyclic spin traps. In this work, their ability to trap O- and C-centered radicals was tested using selected derivatives with different structural modifications. All the studied nitrones were able to trap radicals forming persistent spin adducts, also in the case of OH and OOH radicals which are of wide biological interest as examples of ROS. The stability of the adducts was mainly attributed to the wide delocalization of the unpaired electron over the whole quinoxaline moiety...
September 5, 2017: Organic & Biomolecular Chemistry
Hongbo Peng, Peng Gao, Gang Chu, Bo Pan, Jinhui Peng, Baoshan Xing
In this research, adsorption of Cu(II) and Cd(II) by biochars was investigated. To enhance the adsorption of these two metal ions, a simple modification of biochars by phosphoric acid (H3PO4) was carried out. The surface area was larger and the contents of oxygen-containing functional groups of modified biochars were more than pristine biochars. In comparison with pristine biochar, modified biochars sorbed Cu(II) and Cd(II) much more strongly. Surface area had significant effects on the sorption of Cu(II) and Cd(II) by modified biochars, it also resulted in the higher sorption for the pristine biochar at high pyrolysis temperature...
October 2017: Environmental Pollution
Lindie Marais, Jordi Burés, Johan H L Jordaan, Selwyn Mapolie, Andrew J Swarts
Herein a bis(pyridyl)-N-alkylamine/Cu(I)/TEMPO/NMI catalyst system is reported for aerobic oxidation of a variety of primary alcohols to the corresponding aldehydes using readily available reagents, at room temperature and ambient air as the oxidant. ESI-MS analysis of the reaction showed the formation of a [(L1)(NMI)Cu(II)-OOH](+) species, which is a key intermediate in the alcohol oxidation reaction. Evaluation of the effect of reaction parameters on the initial rate of the reaction allowed us to obtain the optimum conditions for catalytic activity...
August 23, 2017: Organic & Biomolecular Chemistry
Zhen Chen, Yue Wu, Yi-Shing Ma, Yuu Kobayashi, Yao-Yao Zhao, Yusuke Miura, Hitoshi Chiba, Shu-Ping Hui
Cardiolipin (CL) exists as crucial functional phospholipid in mitochondria. The oxidation of CL is concerned with mitochondrial dysfunction and various diseases. As main oxidation products, CL hydroperoxide (CL-OOH) plays a key role in intermediating oxidative reaction. Thus, direct analysis of CL-OOH is of great interest. In the present study, CL and CL-OOH profiles were analyzed in oxidized HepG2 cell lipid via HPLC-Orbitrap MS/MS. Furthermore, the contents of individual molecular species were compared between intact and AAPH-oxidized HepG2 cells...
July 31, 2017: Analytical and Bioanalytical Chemistry
Jaeshin Kim, Shihe Xu
An accurate understanding of the fate of volatile methylsiloxanes (VMS) in air is crucial for determining their persistence and concentrations in the environment. Although oxidation by atmospheric hydroxyl radicals (•OH) is considered as a major degradation mechanism for airborne VMS, the existing bimolecular rate constants with •OH measured and modeled for any given VMS compound varied greatly, depending on the approaches used to generate the data. The objectives of the present study were to measure •OH reaction rate constants for 4 cyclic and 4 linear VMS based on a relative rate method using a newly designed atmospheric chamber and to establish structure-reactivity relationships for the kinetics...
July 18, 2017: Environmental Toxicology and Chemistry
X R J Moors, K Rijs, D Den Hartog, R J Stolker
PURPOSE: To determine the outcome of out-of-hospital (OOH) cardiopulmonary resuscitation (CPR) and the advanced life support (ALS) procedures provided in pediatrics by the Rotterdam Helicopter Emergency Medical Service (HEMS) METHODS: Retrospective evaluation of all pediatric (0-17 years) OOH cardiopulmonary arrests within a 6-year period and attended by the Rotterdam HEMS team. RESULTS: There were 201 OOH CPRs from October 2008 until October 2014. Endotracheal intubation was performed in 164 cases and done by HEMS in 104 patients (63%), intraosseous/intravenous cannulation 43/27 times, and additional medication given by HEMS in 70 patients (35%)...
July 15, 2017: European Journal of Trauma and Emergency Surgery: Official Publication of the European Trauma Society
Giorgio Cozza, Monica Rossetto, Valentina Bosello-Travain, Matilde Maiorino, Antonella Roveri, Stefano Toppo, Mattia Zaccarin, Lucio Zennaro, Fulvio Ursini
GPx4 is a monomeric glutathione peroxidase, unique in reducing the hydroperoxide group (-OOH) of fatty acids esterified in membrane phospholipids. This reaction inhibits lipid peroxidation and accounts for enzyme's vital role. Here we investigated the interaction of GPx4 with membrane phospholipids. A cationic surface near the GPx4 catalytic center interacts with phospholipid polar heads. Accordingly, SPR analysis indicates cardiolipin as the phospholipid with maximal affinity to GPx4. Consistent with the electrostatic nature of the interaction, KCl increases the KD...
July 12, 2017: Free Radical Biology & Medicine
Nicholas Drachman, Stephen Kadlecek, Ian Duncan, Rahim Rizi
The transient nature of intermediate states in chemical reactions has made their detailed investigation difficult. In this study, we demonstrate the utility of hyperpolarized (13)C-NMR to directly observe and quantify the kinetics of the intermediate compound in the non-enzymatic decarboxylation of pyruvate via H2O2 with time resolutions of <1 s. Reactants were sequentially added to a reaction vessel within a 9.4 T NMR magnet while continuously acquiring spectra with a low flip angle, producing the first direct observation at room temperature of the previously proposed reaction intermediate, 2-hydroperoxy-2-hydroxypropanoate...
July 26, 2017: Physical Chemistry Chemical Physics: PCCP
Sudipta Chatterjee, Kushal Sengupta, Biswajit Mondal, Subal Dey, Abhishek Dey
Reactivity as well as selectivity are crucial in the activation and electrocatalytic reduction of molecular oxygen. Recent developments in the understanding of the mechanism of electrocatalytic O2 reduction by iron porphyrin complexes in situ using surface enhanced resonance Raman spectroscopy coupled to rotating disc electrochemistry (SERRS-RDE) in conjunction with H/D isotope effects on electrocatalytic current reveals that the rate of O2 reduction, ∼10(4) to 10(5) M(-1) s(-1) for simple iron porphyrins, is limited by the rate of O-O bond cleavage of an intermediate ferric peroxide species (Fe(III)-OOH)...
July 7, 2017: Accounts of Chemical Research
Yang Yang, Changqing Dai, Adrian Fisher, Yanchun Shen, Daojian Cheng
Oxygen reduction and hydrogen peroxide reduction are technologically important reactions in energy-conversion devices. In this work, a full understanding of oxygen reduction reaction (ORR) mechanism on Au(1 1 1) surface is investigated by density functional theory (DFT) calculations, including the reaction mechanisms of O2 dissociation, OOH dissociation, and H2O2 dissociation. Among these ORR mechanisms on Au(1 1 1), the activation energy of [Formula: see text] hydrogenation reaction is much lower than that of [Formula: see text] dissociation, indicating that [Formula: see text] hydrogenation reaction is more appropriate at the first step than [Formula: see text] dissociation...
September 13, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Xiaoxu Sun, Kai Li, Cong Yin, Ying Wang, Feng He, Hao Tang, Zhijian Wu
Non-precious metal catalysts have attracted particular interest in recent years due to their promising ORR (oxygen reduction reaction) activity in fuel cells. In this work, the structural stability and ORR mechanism of CoN3 embedded graphene have been studied theoretically in acid media. The results indicate that CoN3 embedded graphene is stable thermodynamically. The kinetically most favorable reaction pathway for the ORR is a four-electron process. The process of OOH hydrogenation to generate O + H2O is the most favorable pathway...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
Tristan Asset, Raphael Chattot, Jakub Drnec, Pierre Bordet, Nathalie Job, Frederic Maillard, Laetitia Dubau
The oxygen reduction reaction (ORR) activity of Pt-alloy electrocatalysts depends on (i) the strain/ligand effects induced by the non-noble metal (3d-transition metal or a rare-earth element) alloyed to Pt, (ii) the orientation of the catalytic surfaces, and (iii) the density of structural defects (SDs) (e.g., vacancies, voids, interconnections). These SDs influence the "generalized" coordination number of Pt atoms, the Pt-alloy lattice parameter, and thus the adsorption strength of the ORR intermediates (O*, OH*, OOH*)...
July 18, 2017: ACS Applied Materials & Interfaces
Guttorm Raknes, Steinar Hunskaar
BACKGROUND: Frequencies of reasons for encounter (RFEs) in emergency primary care out-of-hours (OOH) services are relevant for planning of capacities as well as to target the training of staff at casualty clinics. We aimed to present frequencies of RFEs in the different organ systems, and to identify the most frequent RFEs at different urgency levels. METHODS: We analyzed data on RFEs in Norwegian OOH services. International Classification of Primary Care (ICPC-2) RFE codes were recorded in all contacts to eight representative OOH casualty clinics in 2014 and 2015 covering 20 municipalities with a total population of 260 196...
June 24, 2017: BMC Emergency Medicine
Natav Yatom, Yuval Elbaz, Shelly Navon, Maytal Caspary Toroker
Hematite's (α-Fe2O3) major limitation to efficiently splitting water using sunlight is the low rate of the oxygen evolution reaction (OER). Thus, identifying the OER rate limiting step is a cornerstone to enhancing the current under low applied potential. Different measurement techniques showed similar absorption difference spectra during a change in applied potential on the hematite anode below and above the onset of the OER in the dark and under light. This absorption change was shown to result from surface modification during the OER, but the specific surface species could not be resolved...
June 22, 2017: Physical Chemistry Chemical Physics: PCCP
Shaohong Liu, Zhiyu Wang, Si Zhou, Fengjiao Yu, Mengzhou Yu, Chang-Yang Chiang, Wuzong Zhou, Jijun Zhao, Jieshan Qiu
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are cornerstone reactions for many renewable energy technologies. Developing cheap yet durable substitutes of precious-metal catalysts, especially the bifunctional electrocatalysts with high activity for both ORR and OER reactions and their streamlined coupling process, are highly desirable to reduce the processing cost and complexity of renewable energy systems. Here, a facile strategy is reported for synthesizing double-shelled hybrid nanocages with outer shells of Co-N-doped graphitic carbon (Co-NGC) and inner shells of N-doped microporous carbon (NC) by templating against core-shell metal-organic frameworks...
June 19, 2017: Advanced Materials
Yuqian Liu, Xiuyun Cao, Hui Li, Zijun Zhou, Siyang Wang, Zhicong Wang, Chunlei Song, Yiyong Zhou
Phosphorus (P) fractionation and sorption behavior as well as the abundance and community composition of phosphorus-solubilizing bacteria (PSB) in sediments, including inorganic phosphate-solubilizing bacteria (IPB) and organic phosphate-mineralizing bacteria (OPB), were investigated in 27 sampling sites of five sections in the Three Gorges Reservoir (TGR) in December 2012. The calcium-bound phosphorus (CaCO3∼P) accounted for the largest part for P fractions in the sediment of TGR, which was paralleled with IPB outnumbering OPB...
July 2017: Environmental Science and Pollution Research International
J F Ebert, L Huibers, F K Lippert, B Christensen, M B Christensen
BACKGROUND: Out-of-hours (OOH) health care for acute medical problems is often challenged by long waiting time for callers in need of advice and triage. Allowing patients to bypass the OOH telephone waiting line may increase patient satisfaction and provide them with a feeling of safety. We aimed to develop an "emergency access button" enabling patients to bypass the normal telephone waiting line in out-of-hours primary care (OOH-PC) if they perceive their condition to be critical and to evaluate the effect of introducing the button in terms of patient satisfaction and their feeling of safety...
May 31, 2017: BMC Health Services Research
Bishnu Thapa, H Bernhard Schlegel
Acid dissociation constants (pKa's) are key physicochemical properties that are needed to understand the structure and reactivity of molecules in solution. Theoretical pKa's have been calculated for a set of 72 organic compounds with -OH and -OOH groups (48 with known experimental pKa's). This test set includes 17 aliphatic alcohols, 25 substituted phenols, and 30 hydroperoxides. Calculations in aqueous medium have been carried out with SMD implicit solvation and three hybrid DFT functionals (B3LYP, ωB97XD, and M06-2X) with two basis sets (6-31+G(d,p) and 6-311++G(d,p))...
June 8, 2017: Journal of Physical Chemistry. A
Xuqiang Ji, Shuai Hao, Fengli Qu, Jingquan Liu, Gu Du, Abdullah M Asiri, Liang Chen, Xuping Sun
The exploration of high-performance and earth-abundant water oxidation catalysts operating under mild conditions is highly attractive and challenging. In this communication, core-shell CoFe2O4@Co-Fe-Bi nanoarray on carbon cloth (CoFe2O4@Co-Fe-Bi/CC) was successfully fabricated by in situ surface amorphization of CoFe2O4 nanoarray on CC (CoFe2O4/CC). As a 3D water oxidation electrode, CoFe2O4@Co-Fe-Bi/CC shows outstanding activity with an overpotential of 460 mV to drive a geometrical catalytic current density of 10 mA cm(-2) in 0...
May 31, 2017: Nanoscale
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