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https://www.readbyqxmd.com/read/28104245/assessing-kinematics-and-kinetics-of-functional-electrical-stimulation-rowing
#1
Adina E Draghici, Glen Picard, J Andrew Taylor, Sandra J Shefelbine
Hybrid functional electrical stimulation (FES) rowing has positive effects on cardiovascular fitness, producing significantly greater aerobic power than either upper body or FES exercise alone. However, there is minimal information on the kinematics, kinetics, and mechanical efficiency of FES-rowing in the spinal cord injured (SCI) population. This study examined the biomechanics of FES-rowing to determine how motions, forces, and aerobic demand change with increasing intensity. Six individuals with SCI and six able-bodied subjects performed a progressive aerobic capacity rowing test...
January 7, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28102675/mechanistic-elucidation-of-zirconium-catalyzed-direct-amidation
#2
Helena Lundberg, Fredrik Tinnis, Jiji Zhang, Andrés G Algarra, Fahmi Himo, Hans Adolfsson
The mechanism of the zirconium-catalyzed condensation of carboxylic acids and amines for direct formation of amides was studied using kinetics, NMR-spectroscopy and DFT-calculations. The reaction is found to be first order with respect to catalyst and has a positive rate dependence on amine concentration and a negative rate dependence on carboxylic acid concentration. Kinetic experiments using Reaction Progress Kinetic Analysis (RPKA) protocols demonstrate that inhibition of the catalyst by the amide product can be avoided using a high amine concentration...
January 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28101949/highly-active-three-dimensional-nife-cu2o-nanowires-cu-foam-electrode-for-water-oxidation
#3
Yan Gao, Hu Chen, Licheng Sun
Water splitting is of paramount importance for exploiting renewable energy conversion and storage systems, but is greatly hindered by the kinetically sluggish oxygen evolution reaction. Here, we develop a three-dimensional, greatly efficient and durable NiFe/Cu2O nanowires/Cu foam anode (NiFe/Cu2O NWs/CF) for water oxidation in 1.0 M KOH. The obtained electrode exhibited a current density of 10 mA/cm2 at a uniquely low overpotential of 215 mV and can keep a steady current density of 100 mA/cm2 for 50 h at an overpotential of 260 mV...
January 18, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28096387/kinetic-assay-shows-that-increasing-red-cell-volume-could-be-a-treatment-for-sickle-cell-disease
#4
Quan Li, Eric R Henry, James Hofrichter, Jeffrey F Smith, Troy Cellmer, Emily B Dunkelberger, Belhu B Metaferia, Stacy Jones-Straehle, Sarah Boutom, Garrott W Christoph, Terri H Wakefield, Mary E Link, Dwayne Staton, Erica R Vass, Jeffery L Miller, Matthew M Hsieh, John F Tisdale, William A Eaton
Although it has been known for more than 60 years that the cause of sickle cell disease is polymerization of a hemoglobin mutant, hydroxyurea is the only drug approved for treatment by the US Food and Drug Administration. This drug, however, is only partially successful, and the discovery of additional drugs that inhibit fiber formation has been hampered by the lack of a sensitive and quantitative cellular assay. Here, we describe such a method in a 96-well plate format that is based on laser-induced polymerization in sickle trait cells and robust, automated image analysis to detect the precise time at which fibers distort ("sickle") the cells...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28095747/effects-of-roller-massager-on-muscle-recovery-after-exercise-induced-muscle-damage
#5
Nuno Casanova, Joana F Reis, João R Vaz, Rita Machado, Bruno Mendes, Duane C Button, Pedro Pezarat-Correia, Sandro R Freitas
Two experiments (n = 10) were conducted to determine the effects of roller massager (RM) on ankle plantar flexor muscle recovery after exercise-induced muscle damage (EIMD). Experiment 1 examined both functional [i.e., ankle plantar flexion maximal isometric contraction and submaximal (30%) sustained force; ankle dorsiflexion maximal range of motion and resistance to stretch; and medial gastrocnemius pain pressure threshold] and morphological [cross-sectional area, thickness, fascicle length, and fascicle angle] variables, before and immediately, 1, 24, 48, and 72 h after an EIMD stimulus...
January 18, 2017: Journal of Sports Sciences
https://www.readbyqxmd.com/read/28093675/solar-photocatalytic-degradation-of-textile-effluent-with-tio2-zno-and-nb2o5-catalysts-assessment-of-photocatalytic-activity-and-mineralization
#6
Renata P Souza, Elizangela Ambrosio, Maisa T F Souza, Thábata K F S Freitas, Ana M Ferrari-Lima, Juliana C Garcia
The photocatalytic degradation of textile effluent was investigated using TiO2, ZnO, and Nb2O5 catalysts under solar irradiation. The procedures were carried out at ambient conditions in April 2014, with pH 3.0 and catalyst concentration of 0.250 g L(-1). The photocatalytic activity of the oxides was evaluated by means of kinetic efficiency (rate constant and half-life time), chemical oxygen demand reduction, and absorbance reduction at 228, 254, 284, 310, 350, 500, and 660 nm (λmáx). Mineralization in terms of the formation of inorganic ions and toxicity reduction using bioassays with Artemia salina were performed...
January 16, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28092755/coagulation-flocculation-sequential-with-fenton-or-photo-fenton-processes-as-an-alternative-for-the-industrial-textile-wastewater-treatment
#7
Edison GilPavas, Izabela Dobrosz-Gómez, Miguel Ángel Gómez-García
In this study, the industrial textile wastewater was treated using a chemical-based technique (coagulation-flocculation, C-F) sequential with an advanced oxidation process (AOP: Fenton or Photo-Fenton). During the C-F, Al2(SO4)3 was used as coagulant and its optimal dose was determined using the jar test. The following operational conditions of C-F, maximizing the organic matter removal, were determined: 700 mg/L of Al2(SO4)3 at pH = 9.96. Thus, the C-F allowed to remove 98% of turbidity, 48% of Chemical Oxygen Demand (COD), and let to increase in the BOD5/COD ratio from 0...
January 13, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28092434/3d-probed-lipid-dynamics-in-small-unilamellar-vesicles
#8
Meng-Hsuan Chao, Yen-Ting Lin, Namasivayam Dhenadhayalan, Hsin-Lung Lee, Hsin-Yen Lee, King-Chuen Lin
Single-molecule fluorescence correlation spectroscopy overcomes the resolution barrier of optical microscopy (10≈-20 nm) and is utilized to look into lipid dynamics in small unilamellar vesicles (SUVs; diameter < 100 nm). The fluorescence trajectories of lipid-like tracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine (DiD) in the membrane bilayers are acquired at a single-molecule level. The autocorrelation analysis yields the kinetic information on lipid organization, oxygen transport, and lateral diffusion in SUVs' membrane...
January 16, 2017: Small
https://www.readbyqxmd.com/read/28088851/monitoring-the-reaction-process-during-the-s2%C3%A2-s3-transition-in-photosynthetic-water-oxidation-using-time-resolve-infrared-spectroscopy
#9
Hiroki Sakamoto, Tatsuki Shimizu, Ryo Nagao, Takumi Noguchi
Photosynthetic water oxidation performed at the Mn4CaO5 cluster in photosystem II plays a crucial role in energy production as electron and proton sources necessary for CO2 fixation. Molecular oxygen, a byproduct, is a source of the oxygenic atmosphere that sustains life on earth. However, the molecular mechanism of water oxidation is not yet well understood. In the reaction cycle of intermediates called S states, the S2→S3 transition is particularly important; it consists of multiple processes of electron transfer, proton release, and water insertion, and generates an intermediate leading to O-O bond formation...
January 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28088096/mycelium-transformation-of-streptomyces-toxytricini-into-pellet-role-of-culture-conditions-and-kinetics
#10
Punit Kumar, Kashyap Kumar Dubey
The present study envisages the role of different carbon sources, nitrogen sources, metals, pH, inoculum volume and agitation rate in pellet formation of S. toxytricini at shake-flask level. It was found that galactose, ammonium sulphate, sodium nitrate, Cu(2+), Zn(2+), higher inoculum volume (5% v/v) and agitation rate at 300rpm caused significant reduction in pellet size (up to the range of 30μm-0.5mm) but biomass formations was also reduced subsequently. Interestingly diffused type of morphology was obtained in Fe(2+) supplemented medium with reduced biomass (1...
January 6, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28075553/double-layer-graphene-outperforming-monolayer-as-catalyst-on-silicon-photocathode-for-hydrogen-production
#11
Uk Sim, Joonhee Moon, Joohee Lee, JungHyun An, Hyo-Yong Ahn, Dong Jin Kim, Insu Jo, Cheolho Jeon, Seungwu Han, Byung Hee Hong, Ki Tae Nam
Photoelectrochemical cells are used to split hydrogen and oxygen from water molecules to generate chemical fuels to satisfy our ever-increasing energy demands. However, it is a major challenge to design efficient catalysts to use in the photoelectochemical process. Recently, research has focused on carbon-based catalysts, as they are non-precious and environmentally benign. Interesting advances have also been made in controlling nanostructure interfaces and in introducing new materials as catalysts in the photoelectrochemical cell...
January 11, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28067933/mechanism-and-kinetics-of-the-electrocatalytic-reaction-responsible-for-the-high-cost-of-hydrogen-fuel-cells
#12
Tao Cheng, William A Goddard, Qi An, Hai Xiao, Boris Merinov, Sergey Morozov
The sluggish oxygen reduction reaction (ORR) is a major impediment to the economic use of hydrogen fuel cells in transportation. In this work, we report the full ORR reaction mechanism for Pt(111) based on Quantum Mechanics (QM) based Reactive metadynamics (RμD) simulations including explicit water to obtain free energy reaction barriers at 298 K. The lowest energy pathway for 4 e(-) water formation is: first, *OOH formation; second, *OOH reduction to H2O and O*; third, O* hydrolysis using surface water to produce two *OH and finally *OH hydration to water...
January 9, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28067647/decomposition-of-xenobiotics-during-visible-light-irradiation-in-the-presence-of-immobilised-photosensitisers-kinetics-study
#13
M Olak-Kucharczyk, M Foszpańczyk, M Gmurek, S Ledakowicz
The objective of this work was to study the photosensitised oxidation of the xenobiotics benzylparaben (BeP) and 2,4dichlorophenol (2,4DCP) in aqueous solutions using photosensitisers immobilised into chitosan carrier particles and visible light radiation. Zn(II) phthalocyanine tetrasulfonate tetrasodium salt and Al(III) phthalocyanine chloride tetrasulfonic acid were used as photosensitisers. The major role of the singlet oxygen during photodegradation was proven by using scavengers of reactive oxygen species...
January 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28067641/kinetic-degradation-of-guar-gum-in-oilfield-wastewater-by-photo-fenton-process
#14
Shunwu Wang, Ziwang Li, Qinglong Yu
Guar gum is considered as a main component of oilfield wastewater. This work is intended to optimize the experimental conditions (H2O2 dosage, Fe(2+) dosage, initial concentration of organics, initial pH and temperature) for the maximum oxidative degradation of guar gum by Fenton's reagent. The kinetics of guar gum removal were evaluated by means of the chemical oxygen demand (COD) and the absorbance measurements. The batch experiment results showed that the optimum conditions were: H2O2 dosage, 10,000 mg/L; Fe(2+)dosage, 2,000 mg/L; initial concentration of organics, 413 mg/L; pH, 3 and temperature, 35 °C, under which the COD removal could reach 61...
January 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28066550/a-microfluidic-based-cell-encapsulation-platform-to-achieve-high-long-term-cell-viability-in-photopolymerized-pegnb-hydrogel-microspheres
#15
Zhongliang Jiang, Bingzhao Xia, Ralph McBride, John Oakey
Cell encapsulation within photopolymerized polyethylene glycol (PEG)-based hydrogel scaffolds has been demonstrated as a robust strategy for cell delivery, tissue engineering, regenerative medicine, and developing in vitro platforms to study cellular behavior and fate. Strategies to achieve spatial and temporal control over PEG hydrogel mechanical properties, chemical functionalization, and cytocompatibility have advanced considerably in recent years. Recent microfluidic technologies have enabled the miniaturization of PEG hydrogels, thus enabling the fabrication of miniaturized cell-laden vehicles...
January 7, 2017: Journal of Materials Chemistry. B, Materials for Biology and Medicine
https://www.readbyqxmd.com/read/28063007/oxygen-exchange-and-energy-metabolism-in-erythrocytes-of-rett-syndrome-and-their-relationships-with-respiratory-alterations
#16
Chiara Ciaccio, Donato Di Pierro, Diego Sbardella, Grazia Raffaella Tundo, Paolo Curatolo, Cinzia Galasso, Marta Elena Santarone, Maurizio Casasco, Paola Cozza, Alessio Cortelazzo, Marcello Rossi, Claudio De Felice, Joussef Hayek, Massimo Coletta, Stefano Marini
Rett syndrome (RTT) is a neurodevelopmental disorder, mainly affecting females, which is associated to a mutation on the methyl-CpG-binding protein 2 gene. In the pathogenesis and progression of classic RTT, red blood cell (RBC) morphology has been shown to be an important biosensor for redox imbalance and chronic hypoxemia. Here we have evaluated the impact of oxidation and redox imbalance on several functional properties of RTT erythrocytes. In particular, we report for the first time a stopped-flow measurement of the kinetics of oxygen release by RBCs and the analysis of the intrinsic affinity of the hemoglobin (Hb)...
January 7, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28061402/sequentially-crosslinked-bioactive-hydrogels-as-nano-patterned-substrates-with-customizable-stiffness-and-degradation-for-corneal-tissue-engineering-applications
#17
Muhammad Rizwan, Gary S L Peh, Heng-Pei Ang, Nyein Chan Lwin, Khadijah Adnan, Jodhbir S Mehta, Wui Siew Tan, Evelyn K F Yim
Naturally-bioactive hydrogels like gelatin provide favorable properties for tissue-engineering but lack sufficient mechanical strength for use as implantable tissue engineering substrates. Complex fabrication or multi-component additives can improve material strength, but often compromises other properties. Studies have shown gelatin methacrylate (GelMA) as a bioactive hydrogel with diverse tissue growth applications. We hypothesize that, with suitable material modifications, GelMA could be employed for growth and implantation of tissue-engineered human corneal endothelial cell (HCEC) monolayer...
March 2017: Biomaterials
https://www.readbyqxmd.com/read/28061341/enhanced-reactivity-of-microscale-fe-cu-bimetallic-particles-mfe-cu-with-persulfate-ps-for-p-nitrophenol-pnp-removal-in-aqueous-solution
#18
Qingqing Ji, Jun Li, Zhaokun Xiong, Bo Lai
In this study, batch experiments were conducted to examine the enhanced reactivity of microscale Fe/Cu bimetallic particles (mFe/Cu) with persulfate (PS) for p-nitrophenol (PNP) removal in aqueous solution. The key operating parameters (i.e., theoretical Cu mass loadings (TMLCu), mFe/Cu dosage, PS dose, initial pH and temperature) were optimized by the batch experiments, respectively. The experimental data were followed well the pseudo-first-order kinetic model. Result reveals that refractory PNP (500 mg L(-1)) was effectively degraded by mFe/Cu-PS system with removal of 98...
December 27, 2016: Chemosphere
https://www.readbyqxmd.com/read/28060508/an-exploration-of-the-singlet-o2-oxidation-of-8-oxoguanine-by-guided-ion-beam-scattering-and-density-functional-theory-changes-of-reaction-intermediates-energetics-and-kinetics-upon-ionization-and-hydration
#19
Yan Sun, Wenchao Lu, Jianbo Liu
8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) is one of the most common DNA lesions resulting from reactive oxygen species and ionizing radiation, and is involved in mutagenesis, carcinogenesis and cell death. Notably, 8-oxodGuo is more reactive toward singlet (a(1)Δg) O2 than the undamaged guanosine, and the lesions arising from the secondary oxidation of 8-oxodGuo are more mutagenic. Herein the (1)O2 oxidation of free base 8-oxoguanine (8-oxoG) was investigated at different initial conditions including protonated [8-oxoG + H](+), deprotonated [8-oxoG - H](-) and their monohydrates...
January 6, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28059464/adults-with-initial-metabolic-syndrome-have-altered-muscle-deoxygenation-during-incremental-exercise
#20
Alessandro da Costa Machado, Thales Coelho Barbosa, Allan Robson Kluser Sales, Marcio Nogueira de Souza, Antonio Claudio Lucas da Nóbrega, Bruno Moreira Silva
OBJECTIVE: Reduced aerobic power is independently associated with metabolic syndrome (MetS) incidence and prevalence in adults. This study investigated whether muscle deoxygenation (proxy of microvascular O2 extraction) during incremental exercise is altered in MetS and associated with reduced oxygen consumption ( V˙O2peak ). METHODS: Twelve men with initial MetS (no overt diseases and medication-naive; mean ± SD, age 38 ± 7 years) and 12 healthy controls (HCs) (34 ± 7 years) completed an incremental cycling test to exhaustion, in which pulmonary ventilation and gas exchange (metabolic analyzer), as well as vastus lateralis deoxygenation (near infrared spectroscopy), were measured...
January 6, 2017: Obesity
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