bluuebunny/crossref_metadata_2025 huggingface dataset:
Passivation in Non-Random Solid-Solution Alloys
Authors: Artymowicz Dorota M , Sieradzki Karl , Newman Roger C.
Published: October 2013

Results from large-cell Monte Carlo renormalization group calculations for the effects of ordering and clustering on site percolation thresholds in bcc alloys are presented. The results demonstrate that for the case of relatively small positive heats of mixing (0.015 eV/atom), the site percolation threshold is lowered from its conventional value of ~0.25 to 0.16. Conversely, for a small negative heat of mixing (-0.015 eV/atom), the threshold increases to ~0.30. The implications of these results on corrosion/passivation in the context of the integrity of materials for nuclear power systems are indicated.
Nitric Acid Reduction on 316L Stainless Steel under Conditions Representative of Reprocessing
Authors: Woodhouse Rebecca C. , Boxall Colin , Wilbraham Richard J.
Published: October 2013

Steels comprise the largest class of metal-based materials encountered on nuclear sites. An understanding of how process steels interact with HNO3 in spent fuel treatment plant environments is required to enable informed decisions to be made about the design and effective application of different steel types within nuclear environments. Stainless steels readily passivate in nitric acid. However, increasing the oxidising power of the media can lead to passive film dissolution, resulting in rapid transpassive corrosion. The corrosion of steels in nitric acid is further complicated by the autocatalytic reduction of HNO3 to aqueous HNO2 which attacks the steel surface. This paper describes the effect of this behaviour on process steels in stagnant and/or flowing conditions using electrochemical and microgravimetric based methods. We describe linear sweep voltammetry studies performed on a 316L stainless steel rotating disk electrodes in varying concentrations of nitric acid and rotation speeds and provide a qualitative interpretation of the results and what these imply about the mechanism of HNO3 reduction. These findings will be used in follow on studies to determine the kinetic parameters of the nitric acid reduction reaction at the surface of 316L stainless steel.
Corrosion Behavior of AGR Simulated Fuels – Evolution of the Fuel Surface
Authors: Rauff-Nisthar Nadya , Boxall Colin , Farnan Ian , Hiezl Zoltan , Lee William , Perkins Chris , Wilbraham Richard J.
Published: October 2013

We have prepared a range of Advanced Gas-cooled Reactor (AGR) SIMFUELs at a range of simulated burn ups and, using Raman spectroscopy, have studied the effect of the SIMFUEL dopants on the UO2 crystal structure. We have also studied the effect of deliberately added hydrogen peroxide on the SIMFUEL surface. The intensity of the fundamental U-O stretch (445 cm-1) decreases as the amount of dopant increases in each SIMFUEL burn up composition. A simultaneous increase in the lattice damage (500 – 700 cm-1) peak is observed as the UO2 cubic fluorite lattice structure becomes more distressed and moves towards a tetragonal structure. Exposure to 100 µmol dm-3 H2O2 further decreases the fundamental U-O stretch and increases the lattice damage peak, suggesting that additional point defects are established as the concentration of interstitial oxygen is increased in the lattice via the H2O2 induced corrosion of the SIMFUEL.
Microwave Assisted Self-Combustion Synthesis and Electrochemical Performance of LSCF-SDC Composite Cathodes
Authors: Macedo Daniel Araújo de , Cesário Moises R , Melo Dulce Maria de Araujo , Nascimento Rubens M. , Paskocimas Carlos A. , Martinelli Antonio Eduardo , Fagg Duncan Paul
Published: October 2013

La0.6Sr0.4Co0.2Fe0.8O3-Ce0.8Sm0.2O1.9 (LSCF-SDC, 50 wt.% SDC) composite powders were synthesized by microwave assisted self-combustion. Powder characterization was carried out by XRD and TEM. Screen-printed LSCF-SDC composite electrodes with different microstructures were obtained on CGO pellets. The electrochemical performance for the oxygen reduction reaction was investigated by impedance spectroscopy varying both the temperature (600 – 800 °C) and oxygen partial pressure at 750 °C. The results of the electrochemical characterization indicated a significant reduction in the area specific resistance (ASR) of the cathodes prepared at different sintering conditions, highlighting that the electrode resistance can be manipulated by microstructural design. The lowest value of ASR in pure oxygen, 0.18 ohm.cm2 at 750 °C, is attributed to specific microstructural features, such as good connectivity between LSCF and SDC grains and a well developed open pore network, observed for the composite cathode sintered at 1150 °C for 2 h. The dependence of ASR on pO2 shows that the charge-transfer process is the rate limiting step for oxygen reduction.
Photoelectrochemical Properties of α-Fe2O3:Sn/CuFe2O4 Composite Nanorod Arrays as Photoanodes
Authors: Wu Kun , Liu Chunting , Shang Mingwei , Zhu Qianqian , Dong Lifeng
Published: October 2013

α-Fe2O3:Sn/CuFe2O4 composite electrodes are prepared to improve the photoelectrochemical properties via a simple solution/heat treatment performed for α-Fe2O3:Sn nanorod electrodes on fluoride tin oxide glass substrates. Based on the characterizations and analysis of X-ray diffraction and field emission scanning electron microscopy with energy-dispersive spectroscopy, it was found that a crystalline CuFe2O4 phase for composite electrodes was formed after treatment. Compared to the bare α-Fe2O3:Sn electrode, significantly enhanced photocurrent density for α-Fe2O3:Sn/CuFe2O4 composite electrodes was also found in the photoelectrochemical measurements because CuFe2O4 has conduction and valence band edges shifted from those of Fe2O3, which allows for the efficient separation of electron-hole pairs at the α-Fe2O3:Sn/CuFe2O4 interface.
Dimensionally Stable Anodes (DSA®) for Electrochemical Water Splitting: Redox Properties, OER Kinetics and Mechanism at RuO2/ NiO Modified Electrodes in Aqueous Base
Authors: Godwin Ian , Lyons Michael E.G.
Published: October 2013

The RuO2/NiO electrode was found to be extremely effective as a water oxidation catalyst in alkaline conditions. Addition of 25 mol % of RuO2 to a NiO electrode lowered the oxygen evolution reaction (OER) overpotential by ca. 30 %. Based on kinetic data obtained we have proposed a mechanism for both RuO2 and NiO utilizing the surfaquo group concept which envisages water oxidation occurring at hydrated interlinked oxy-metal surface active groups.
The Electrolytic Dissociation of 1,2-Cyclopentanedicarboxylic Acids
Authors: Kvaratskhelia Elene , Kvaratskhelia Ramaz , Kurtanidze Rusudan
Published: October 2013

The dissociation parameters for the dilute (0.0001-0.01M) solutions of cis and trans-1,2-cyclopentanedicarboxylic acids were calculated with the aid of the original accurate and empirical equations suggested by authors for cases of electrolytic dissociation of weak multibasic organic acids with the effect of “overlapping” equilibria. The equations for determination the regions of predominance of various charged and uncharged forms of these acids were also suggested.
Electro-Reduction of Dialkyl-2,4,5,7-Tetranitrofluorene-9,9-Dipropionates: Simulation
Authors: Haque Inam ul , Azam Rabia
Published: October 2013

Simulations of cyclic voltammograms of 9,9-bis(alkylpropionate)-2,4,5,7-tetranitrofluorenes in N,N-dimethylformamide, using 0.1 M tetrabutylammonium perchlorate as supporting electrolyte at a mercury-bead cathode, from literature (1), were carried out. Both cathodic and anodic peaks were analyzed using two shareware programs CVSIM and ESP 2.4. CVSIM program written in Turbo Pascal was run using Turbo Pascal free downloaded from web. The ESP 2.4 written in DOS was run using DOS. All the simulations were executed on a PC Pentium IV. Our simulations are consistent with an Electrochemical-Electrochemical (EE) type pathway for compound A and Electrochemical-Electrochemical-Chemical (EEC) mechanism for compound B.
Nanostructured Electrodes and Photoactive Layers for Efficient, Stable and Flexible Organic Photovoltaic Devices
Authors: Servati Peyman , Gholamkhass Bobak , Soltanian Saeid , Rahmanian Rowshan , Mohseni Kiasari Nima , Jiang Zenan , Ko Frank K. , Shen Jun , Aljaafari Abdullah I.
Published: October 2013

This work presents our latest results for conventional and inverted organic photovoltaic (OPV) devices based on polymers such as poly(3-hexylthiophene) (P3HT) and poly[N-9”-hepta-decanyl-2,7-carbazole-alt-5,5-(4’,7’-di-2-thienyl-2’,1’,3’-benzothiadiazole) (PCDTBT) blended with fullerene derivatives such as [6,6]-phenyl C61-butyric acid methyl ester (PC61BM) and PC71BM. It is observed that by controlling the morphology of acceptor and donor domains in the BHJ photoactive films higher power conversion efficiency (PCE) and performance for OPV devices can be achieved, with the best efficiencies demonstrated for the P3HT:PC61BM and PCDTBT:PC71BM devices exceeding 4% and 7%, respectively. Here, the interplay between fabrication processes and the performance of the devices is investigated to achieve optimum PCE, short-circuit current and open-circuit voltage for the OPV devices. In addition to contact and BHJ films, a flexible solar cell requires a flexible transparent conductor (TC). We report our results for conductive electrospun nanofiber based TCs as replacements for the brittle indium tin oxide (ITO) used for solar cells on glass substrates. These novel nanofiber TC web and their associated flexible substrates act as new platforms for fabrication of low cost, flexible solar cells. Performance of the TC is compared to other novel TCs in terms of transparency, sheet resistance and flexibility. The performance of the nanofiber TC webs is manifested in OPV devices that employ these TCs as the transparent electrode and demonstrate comparable performance to the devices using ITO electrodes. This work demonstrates the significance of novel materials and deposition technologies for enabling efficient and stable OPV devices for roll-to-roll manufacturing on flexible substrates.
Ethanol Oxidation in Direct Ethanol Fuel Cells
Authors: Reeb Berthold B.L. , Kluy Norbert , Schneider Oliver , Stimming Ulrich
Published: October 2013

Membrane electrode assemblies (MEAs) for an intermediate temperature fuel cell were prepared and evaluated as direct ethanol fuel cell (DEFC) and as hydrogen fuel cell. As proton conductor, a temperature stable electrolyte for intermediate temperatures with superior ionic conductivity was prepared from ammonium polyphosphate (APP) and metal oxides (e.g. SiO2, TiO2) by a thermal solid state reaction, forming inorganic composite materials with the formula (NH4)2Si(1-x)TixP4O13 (ASi(1-x)TixPP). For membrane fabrication, the electrolyte was embedded in an organic polymer matrix, obtaining flexible membranes. Finally, MEAs were obtained by attaching commercial electrodes on the membrane. The thermal properties of the membranes were investigated by thermogravimetric analysis (TGA), which predicts thermal stability up to 300°C. First preliminary fuel cell results showed a maximum power density of ≈ 8 mW/cm² with hydrogen and oxygen and ≈ 0.6 mW/cm² with a stoichiometric mixture of ethanol/water and oxygen.
Activated Carbons from Orange Peel Waste as Supercapacitor Electrodes
Authors: Arie Arenst Andreas , Kristianto Hans , Lee Joong Kee
Published: October 2013

In this work, activated carbon was prepared from Indonesian local orange peel using ZnCl2 activation method at various chemical ratio. Carbonization was done for 1 hour at 500oC. The structural and morphological characteristics of orange peel based activated carbons were investigated using scanning electron microscope (SEM), Brunaeuer-Emmett-Teller surface analyzer. The highest surface area was found about 1200 m2/gr, obtained from the mass ratio of 1:2 (biomass : ZnCl2). Electrochemical measurement was examined by half cells, using 1M LiPF6 in EC/EMC/DMC solution (1:1:1 v/v) as electrolyte, and Li/Li+ as reference electrode. It was shown from cyclic voltammetry (CV) results that activated carbon from orange peel demonstrated a stable electrochemical characteristics, with specific capacitance of 56 F/g at scan rate of 1mVs-1 at voltage window between 2,5 and 4 V.
A Low Temperature Inorganic Molten Salt Supercapacitor
Authors: Kirk Donald W. , Graydon John W.
Published: October 2013

Porous activated carbon is an important electrode material for devices such as supercapacitors, batteries and fuel cells. Despite the research and commercialization work that has been carried out, there is still a need to understand some of the fundamental characteristics of the role of activated carbon and the electrolyte in charge storage and ion migration within these structures. There has been two general types of electrolytes used; aqueous electrolytes with high concentrations of conductive salts and organic electrolytes modified to be conductive or directly conductive as in the form of ionic liquids. The former have high ionic conductance, the latter have a larger voltage range for stability. In this work we introduce an alternative to theses electrolytes, a low temperature molten inorganic salt. Potential advantages include high conductivity and a large potential operating range. The work demonstrates that inorganic salts can be used as electrolytes in supercapacitors at temperatures as low as 120oC . The charge discharge characteristics were similar to aqueous electrolyte performance and higher charging voltages than the aqueous limits are possible. The work also showed that the activated carbon pore sizes that can be used for charge discharge are similar for the molten salt ions and the aqueous ions.
Reversible Change in Surface Roughness and the Inductive Loop at Electrodes under Corrosion Conditions
Authors: Chazalviel Jean-Noel
Published: October 2013

Electrodes under active dissolution conditions are known to systematically exhibit an inductive behavior in the low-frequency range. The variation of the steady-state specific surface area as a function of potential is explored as the origin of this inductive behavior, using numerical simulations. The results confirm the validity of the mechanism. Especially, the observed relationship between the characteristic frequency of the inductive loop and the steady-state current density is reproduced quantitatively by the simulations.
Citrate Gel Conversion Coating on AZ31 Magnesium Alloys
Authors: Chu Yu-Ren , Lin Chao-Sung
Published: October 2013

A citrate gel conversion system was developed in this study. The citrate gel, which was obtained by adding ethanol into sodium citrate aqueous solution, was dissolved in glycerin to form the conversion solution. After the consecutive steps of roll coating and heating, a citrate gel conversion coating was made on AZ31 magnesium alloys. Microstructure characterization showed that the citrate gel coating was thin and free of cracks resulting from dehydration. As evaluated by electrochemical analyses, this coating apparently reduced the corrosion current density and enhanced the polarization resistance. With the addition of copper sulfate, copper-containing clusters were formed on top of the coating due to the replacement reaction between magnesium substrate and cupric ions, and resulted in a further increase in both the corrosion potential and polarization resistance.
Fe-Doped TiO2 Nanotube Array Films for Photocathodic Protection of Stainless Steel
Authors: Zhu Yan-Feng , Xu Lu , Zhang Juan , Qi Hai-Qing , Du Rong-Gui , Shao Yi-Ze , Lin Chang-Jian
Published: October 2013

A TiO2 film and a Fe-doped TiO2 film were prepared by an electrochemical anodic oxidation method. The effect of Fe on the surface morphology and crystalline structure of the doped film was investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Electrode potential and electrochemical impedance spectroscopy (EIS) measurements were performed to study the protection effect of the film on stainless steel. When 304 stainless steel in a 0.5 M NaCl solution was coupled to the Fe-doped TiO2 film photoanode under illumination, its potential decreased by 450 mV, showing a good photocathodic protection effect. EIS measurements revealed that the charge transfer resistance of the steel coupled to the photoanode decreased considerably.
Investigation of Cyclohexylidenecyclohexanon Steel Corrosion Inhibitor as Surfactant
Authors: Ostapenko Gennady Ivanovich , Gloukhov Pavel Alexandrovich , Bunev Alexander Siyasatovich
Published: October 2013

A modified organic waste of the caprolactam production is investigated by electrochemical impedance spectroscopy technique as a corrosion inhibitor of carbon steel in 20% hydrochloric solution. It is shown that cyclohexylidenecyclohexanon is a basic inhibiting component in such inhibitor. The inhibitor is investigated also as surfactant at the solution – air interface by means of the maximum bubble pressure technique. It is shown that the Langmuir adsorption of inhibitor takes place at solution – air and solution – steel interfaces. Equilibrium adsorption constant values make (1.7±0.4)×103 M-1 and (4.0±0.8)×103 M-1 respectively. Free adsorption energy was estimated as (–28±0.5) kJ mol-1 and (–30±0.6) kJ mol-1 respectively. The closeness of the adsorption constant and the free adsorption energy values suggest that the inhibitor adsorption on steel is caused basically by the hydrophobic interaction of inhibitor molecules with the solution molecules and less depends on the interaction with steel.
(Invited) Porous Carbon and Its Nanocomposites for Energy Storage Applications
Authors: Candelaria Stephanie L. , Huang Yunxia , Zhang Lili , Cao Guozhong
Published: October 2013

Highly porous carbon has been modified on the surface with several different elements, including boron, nitrogen, sulfur, and copper. Surface modification is shown to affect the pore structure, pyrolysis and activation processes, and wetting behavior of the underlying porous carbon. When tested for energy storage applications, the surface modified carbon exhibits increased capacitance, energy density, and power density due to enhanced pore structure and the addition of pseudocapacitive reactions.
Template-Assisted Synthesis and Catalytic Property of Copper Nanowires
Authors: Fan Guowei , Yu Liyan , Dong Lifeng
Published: October 2013

Porous anodic aluminum (PAA) templates with uniform diameter pores were prepared by two step anodic oxidation method. The resultant PAA was characterized using ﬁeld emission scanning electron microscopy (FESEM), and the preparation parameters of PAA templates were investigated. The barrier of PAA was dissolved by electrolyzing neutral solutions with PAA as a cathode and carbon electrode as an anode. Copper nanowires were synthesized with PAA templates by direct current electrodeposition. The resultant copper nanowires were characterized using FESEM. Carbon nanofibers were synthesized by using acetylene as carbon source and copper nanowires as catalysts through chemical vapor deposition. The morphology of carbon nanofibers was characterized using FESEM. It is observed that the product was a film-like and the diameter of fibers was tens of nanometers.
Dietary fat sources differentially modulate intestinal barrier and hepatic inflammation in alcohol-induced liver injury in rats
Authors: Zhong Wei , Li Qiong , Xie Guoxiang , Sun Xiuhua , Tan Xiaobing , Sun Xinguo , Jia Wei , Zhou Zhanxiang
Published: October 2013

Endotoxemia is a causal factor in the development of alcoholic liver injury. The present study aimed at determining the interactions of ethanol with different fat sources at the gut-liver axis. Male Sprague-Dawley rats were pair fed control or ethanol liquid diet for 8 wk. The liquid diets were based on a modified Lieber-DeCarli formula, with 30% total calories derived from corn oil (rich in polyunsaturated fatty acids). To test the effects of saturated fats, corn oil in the ethanol diet was replaced by either cocoa butter (CB, rich in long-chain saturated fatty acids) or medium-chain triglycerides (MCT, exclusively medium-chain saturated fatty acids). Ethanol feeding increased hepatic lipid accumulation and inflammatory cell infiltration and perturbed hepatic and serum metabolite profiles. Ethanol feeding with CB or MCT alleviated ethanol-induced liver injury and attenuated ethanol-induced metabolic perturbation. Both CB and MCT also normalized ethanol-induced hepatic macrophage activation, cytokine expression, and neutrophil infiltration. Ethanol feeding elevated serum endotoxin level, which was normalized by MCT but not CB. In accordance, ethanol-induced downregulations of intestinal occludin and zonula occludens-1 were normalized by MCT but not CB. However, CB normalized ethanol-increased hepatic endotoxin level in association with upregulation of an endotoxin detoxifying enzyme, argininosuccinate synthase 1 (ASS1). Knockdown ASS1 in H4IIEC3 cells resulted in impaired endotoxin clearance and upregulated cytokine expression. These data demonstrate that the protection of saturated fats against alcohol-induced liver injury occur via different actions at the gut-liver axis and are chain length dependent.
Inhibition of NF-κB activation by a novel IKK inhibitor reduces the severity of experimental autoimmune myocarditis via suppression of T-cell activation
Authors: Watanabe Ryo , Azuma Ryoko Wakizono , Suzuki Jun-ichi , Ogawa Masahito , Itai Akiko , Hirata Yasunobu , Komuro Issei , Isobe Mitsuaki
Published: October 2013

NF-κB, which is activated by the inhibitor of NF-κB kinase (IKK), is involved in the progression of inflammatory disease. However, the effect of IKK inhibition on the progression of myocarditis is unknown. We examined the effect of IKK inhibition on the progression of myocarditis. Lewis rats were immunized with porcine cardiac myosin to induce experimental autoimmune myocarditis (EAM). We administered the IKK inhibitor (IMD-0354; 15 mg·kg−1·day−1) or vehicle to EAM rats daily. Hearts were harvested 21 days after immunization. Although the untreated EAM group showed increased heart weight-to-body weight ratio, and severe myocardial damage, these changes were attenuated in the IKK inhibitor-treated group. Moreover, IKK inhibitor administration significantly reduced NF-κB activation and mRNA expression of IFN-γ, IL-2, and monocyte chemoattractant protein-1 in myocardium compared with vehicle administration. In vitro study showed that the IKK inhibitor treatment inhibited T-cell proliferation and Th1 cytokines production induced by myosin stimulation. The IKK inhibitor ameliorated EAM by suppressing inflammatory reactions via suppression of T-cell activation.
Role of 20-HETE, TRPC channels, and BKCa in dysregulation of pressure-induced Ca2+ signaling and myogenic constriction of cerebral arteries in aged hypertensive mice
Authors: Toth Peter , Csiszar Anna , Tucsek Zsuzsanna , Sosnowska Danuta , Gautam Tripti , Koller Akos , Schwartzman Michal Laniado , Sonntag William E. , Ungvari Zoltan
Published: October 2013

Hypertension in the elderly substantially increases the risk of stroke and vascular cognitive impairment in part due to an impaired functional adaptation of aged cerebral arteries to high blood pressure. To elucidate the mechanisms underlying impaired autoregulatory protection in aging, hypertension was induced in young (3 mo) and aged (24 mo) C57BL/6 mice by chronic infusion of angiotensin II and pressure-induced changes in smooth muscle cell (SMC) intracellular Ca2+ concentration ([Ca2+]i) and myogenic constriction of middle cerebral arteries (MCA) were assessed. In MCAs from young hypertensive mice, pressure-induced increases in vascular SMC [Ca2+]i and myogenic tone were increased, and these adaptive responses were inhibited by the cytochrome P-450 ω-hydroxylase inhibitor HET0016 and the transient receptor potential (TRP) channel blocker SKF96365. Administration of 20- hydroxyeicosatetraenoic acid (HETE) increased SMC [Ca2+]i and constricted MCAs, and these responses were inhibited by SKF96365. MCAs from aged hypertensive mice did not show adaptive increases in pressure-induced calcium signal and myogenic tone and responses to HET0016 and SKF96365 were blunted. Inhibition of large-conductance Ca2+-activated K+ (BK) channels by iberiotoxin enhanced SMC [Ca2+]i and myogenic constriction in MCAs of young normotensive animals, whereas it was without effect in MCAs of young hypertensive mice. Iberiotoxin did not restore myogenic adaptation in MCAs of aged hypertensive mice. Thus functional maladaptation of aged cerebral arteries to hypertension is due to the dysregulation of pressure-induced 20-HETE and TRP channel-mediated SMC calcium signaling, whereas overactivation of BK channels is unlikely to play a role in this phenomenon.
Protein nitration impairs the myogenic tone of rat middle cerebral arteries in both ischemic and nonischemic hemispheres after ischemic stroke
Authors: Coucha Maha , Li Weiguo , Johnson Maribeth H. , Fagan Susan C. , Ergul Adviye
Published: October 2013

The myogenic response is crucial for maintaining vascular resistance to achieve constant perfusion during pressure fluctuations. Reduced cerebral blood flow has been reported in ischemic and nonischemic hemispheres after stroke. Ischemia-reperfusion injury and the resulting oxidative stress impair myogenic responses in the ischemic hemisphere. Yet, the mechanism by which ischemia-reperfusion affects the nonischemic side is still undetermined. The goal of the present study was to determine the effect of ischemia-reperfusion injury on the myogenic reactivity of cerebral vessels from both hemispheres and whether protein nitration due to excess peroxynitrite production is the underlying mechanism of loss of tone. Male Wistar rats were subjected to sham operation or 30-min middle cerebral artery occlusion/45-min reperfusion. Rats were administered saline, the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)prophyrinato iron (III), or the nitration inhibitor epicatechin at reperfusion. Middle cerebral arteries isolated from another set of control rats were exposed to ex vivo oxygen-glucose deprivation with and without glycoprotein 91 tat (NADPH oxidase inhibitor) or Nω-nitro-l-arginine methyl ester. Myogenic tone and nitrotyrosine levels were determined. Ischemia-reperfusion injury impaired the myogenic tone of vessels in both hemispheres compared with the sham group ( P < 0.001). Vessels exposed to ex vivo oxygen-glucose deprivation experienced a similar loss of myogenic tone. Inhibition of peroxynitrite parent radicals significantly improved the myogenic tone. Peroxynitrite scavenging or inhibition of nitration improved the myogenic tone of vessels from ischemic ( P < 0.001 and P < 0.05, respectively) and nonischemic ( P < 0.01 and P < 0.05, respectively) hemispheres. Nitration was significantly increased in both hemispheres versus the sham group and was normalized with epicatechin treatment. In conclusion, ischemia-reperfusion injury impairs vessel reactivity in both hemispheres via nitration. We suggest that sham operation rather than the nonischemic side should be used as a control in preclinical stroke studies.
The mouse aortocaval fistula recapitulates human arteriovenous fistula maturation
Authors: Yamamoto Kota , Protack Clinton D. , Tsuneki Masayuki , Hall Michael R. , Wong Daniel J. , Lu Daniel Y. , Assi Roland , Williams Willis T. , Sadaghianloo Nirvana , Bai Hualong , Miyata Tetsuro , Madri Joseph A. , Dardik Alan
Published: October 2013

Several models of arteriovenous fistula (AVF) have excellent patency and help in understanding the mechanisms of venous adaptation to the arterial environment. However, these models fail to exhibit either maturation failure or fail to develop stenoses, both of which are critical modes of AVF failure in human patients. We used high-resolution Doppler ultrasound to serially follow mice with AVFs created by direct 25-gauge needle puncture. By day 21, 75% of AVFs dilate, thicken, and increase flow, i.e., mature, and 25% fail due to immediate thrombosis or maturation failure. Mature AVF thicken due to increased amounts of smooth muscle cells. By day 42, 67% of mature AVFs remain patent, but 33% of AVFs fail due to perianastomotic thickening. These results show that the mouse aortocaval model has an easily detectable maturation phase in the first 21 days followed by a potential failure phase in the subsequent 21 days. This model is the first animal model of AVF to show a course that recapitulates aspects of human AVF maturation.
Discharge of RVLM vasomotor neurons is not increased in anesthetized angiotensin II-salt hypertensive rats
Authors: Pedrino Gustavo R. , Calderon Alfredo S. , Andrade Mary Ann , Cravo Sergio L. , Toney Glenn M.
Published: October 2013

Neurons of the rostral ventrolateral medulla (RVLM) are critical for generating and regulating sympathetic nerve activity (SNA). Systemic administration of ANG II combined with a high-salt diet induces hypertension that is postulated to involve elevated SNA. However, a functional role for RVLM vasomotor neurons in ANG II-salt hypertension has not been established. Here we tested the hypothesis that RVLM vasomotor neurons have exaggerated resting discharge in rats with ANG II-salt hypertension. Rats in the hypertensive (HT) group consumed a high-salt (2% NaCl) diet and received an infusion of ANG II (150 ng·kg−1·min−1 sc) for 14 days. Rats in the normotensive (NT) group consumed a normal salt (0.4% NaCl) diet and were infused with normal saline. Telemetric recordings in conscious rats revealed that mean arterial pressure (MAP) was significantly increased in HT compared with NT rats ( P < 0.001). Under anesthesia (urethane/chloralose), MAP remained elevated in HT compared with NT rats ( P < 0.01). Extracellular single unit recordings in HT ( n = 28) and NT ( n = 22) rats revealed that barosensitive RVLM neurons in both groups (HT, 23 cells; NT, 34 cells) had similar cardiac rhythmicity and resting discharge. However, a greater ( P < 0.01) increase of MAP was needed to silence discharge of neurons in HT (17 cells, 44 ± 5 mmHg) than in NT (28 cells, 29 ± 3 mmHg) rats. Maximum firing rates during arterial baroreceptor unloading were similar across groups. We conclude that heightened resting discharge of sympathoexcitatory RVLM neurons is not required for maintenance of neurogenic ANG II-salt hypertension.
Insulin resistance protects the heart from fuel overload in dysregulated metabolic states
Authors: Taegtmeyer Heinrich , Beauloye Christophe , Harmancey Romain , Hue Louis
Published: October 2013

Reversing impaired insulin sensitivity has been suggested as treatment for heart failure. However, recent clinical evidence suggests the opposite. Here we present a line of reasoning in support of the hypothesis that insulin resistance protects the heart from the consequences of fuel overload in the dysregulated metabolic state of obesity and diabetes. We discuss pathways of myocardial fuel toxicity, as well as several layers of defense against fuel overload. Our reassessment of the literature suggests that in the heart, insulin-sensitizing agents result in an elimination of some of the defenses, leading to cytotoxic damage. In contrast, a normalization of fuel supply should either prevent or reverse the process. Taken together, we offer a new perspective on insulin resistance of the heart.
Metformin-stimulated AMPK-α1 promotes microvascular repair in acute lung injury
Authors: Jian Ming-Yuan , Alexeyev Mikhail F. , Wolkowicz Paul E. , Zmijewski Jaroslaw W. , Creighton Judy R.
Published: October 2013

Acute lung injury secondary to sepsis is a leading cause of mortality in sepsis-related death. Present therapies are not effective in reversing endothelial cell dysfunction, which plays a key role in increased vascular permeability and compromised lung function. AMP-activated protein kinase (AMPK) is a molecular sensor important for detection and mediation of cellular adaptations to vascular disruptive stimuli. In this study, we sought to determine the role of AMPK in resolving increased endothelial permeability in the sepsis-injured lung. AMPK function was determined in vivo using a rat model of endotoxin-induced lung injury, ex vivo using the isolated lung, and in vitro using cultured rat pulmonary microvascular endothelial cells (PMVECs). AMPK stimulation using N1-(α-d-ribofuranosyl)-5-aminoimidizole-4-carboxamide or metformin decreased the LPS-induced increase in permeability, as determined by filtration coefficient ( Kf) measurements, and resolved edema as indicated by decreased wet-to-dry ratios. The role of AMPK in the endothelial response to LPS was determined by shRNA designed to decrease expression of the AMPK-α1 isoform in capillary endothelial cells. Permeability, wounding, and barrier resistance assays using PMVECs identified AMPK-α1 as the molecule responsible for the beneficial effects of AMPK in the lung. Our findings provide novel evidence for AMPK-α1 as a vascular repair mechanism important in the pulmonary response to sepsis and identify a role for metformin treatment in the management of capillary injury.
Regulation of cellular metabolism: programming and maintaining metabolic homeostasis
Authors: Wilson David F.
Published: October 2013

Mitochondrial oxidative phosphorylation is programmed to set and maintain metabolic homeostasis. This is accomplished through an intrinsic program that determines the metabolic [ATP]/[ADP]/[Pi], where [Pi] is the concentration of inorganic phosphate (energy state) and maintains it through a bidirectional sensory/signaling control network that reaches every aspect of cellular metabolism. The program sets the energy state with high precision (to better than one part in 109) and can respond to transient changes in energy demand (ATP use) to more than 100 times the resting rate. Epigenetic and environmental factors are able to “fine tune” the programmed set point over a narrow range to meet the special needs associated with cell differentiation and chronic changes in metabolic requirements. The result is robust, across platform control of metabolism, essential to cellular differentiation and the evolution of complex organisms.
Multibubbles Segmentation and Characteristic Measurement in Gas-Liquid Two-Phase Flow
Authors: Xue Ting , Chen Yanlong , Ge Penghui
Published: October 2013

Gas-liquid two-phase flow is a typical flow, and bubble characteristic measurement is of great importance to discover flow mechanism and guide the practical fluid mechanical engineering. In this paper, a virtual stereo vision measurement system mainly consists of a high-speed camera, and two optical reflector sets was established, and bubble images in gas-liquid two-phase flow were captured by the optimized virtual stereo vision sensor. Overlapping bubbles segmentation is indispensable for the images, and an effective multibubbles segmentation method was proposed. Firstly the convexities of the overlapped area were identified based on the chain code difference, and the pseudoconcave points were removed based on the concave length constraint. According to the matching principle of concave points, the segmentation area was clarified, and the overlapping bubbles were segmented effectively. Therefore, the modality and motion feature parameters of bubbles were estimated, and three-dimensional bubble trajectories and velocity vector field were reconstructed according to the measurement model of virtual stereo vision. The experimental results show that the segmentation and characteristic measurement method of multibubbles is valid and with high precision.
Branching Fractions andCPAsymmetries ofB→K0*1430ρωandB→K0*1430ϕDecays in the Family NonuniversalZ′Model
Authors: Li Ying , Wang En-Lei , Zhang Hong-Yan
Published: October 2013

Within the QCD factorization framework, we investigate the branching fractions and the directCPasymmetries of decaysB→K0*1430ρωandB→K0*1430ϕunder two different scenarios in the standard model and the family nonuniversalZ′model. We find that the annihilation terms play crucial roles in these decays and lead to the major uncertainties. For decaysB-→K0*-1430ρ0ω, the newZ′boson could change the branching fractions remarkably. However, for other decays, its contribution might be clouded by large uncertainties from annihilations. Unfortunately, neither the standard model nor theZ′model can reproduce all experimental data simultaneously under one certain scenario. We also noted that the directCPasymmetries ofB-→K0*-1430ρ0ωcould be used to identify theK0*1430meson and search for the contribution of newZ′boson.
Reconstruction and Analysis of Human Kidney-Specific Metabolic Network Based on Omics Data
Authors: Zhang Ai-Di , Dai Shao-Xing , Huang Jing-Fei
Published: October 2013

With the advent of the high-throughput data production, recent studies of tissue-specific metabolic networks have largely advanced our understanding of the metabolic basis of various physiological and pathological processes. However, for kidney, which plays an essential role in the body, the available kidney-specific model remains incomplete. This paper reports the reconstruction and characterization of the human kidney metabolic network based on transcriptome and proteome data. In silico simulations revealed that house-keeping genes were more essential than kidney-specific genes in maintaining kidney metabolism. Importantly, a total of 267 potential metabolic biomarkers for kidney-related diseases were successfully explored using this model. Furthermore, we found that the discrepancies in metabolic processes of different tissues are directly corresponding to tissue's functions. Finally, the phenotypes of the differentially expressed genes in diabetic kidney disease were characterized, suggesting that these genes may affect disease development through altering kidney metabolism. Thus, the human kidney-specific model constructed in this study may provide valuable information for the metabolism of kidney and offer excellent insights into complex kidney diseases.
Titanium Dioxide Nanoparticles Induced Proinflammation of Primary Cultured Cardiac Myocytes of Rat
Authors: Song Wei , Wang Jiangxue , Liu Meili , Li Ping , Zhou Gang , Li Zhou , Fan Yubo
Published: October 2013

Titanium dioxide (TiO2) nanoparticles are widely used in electronics, biology, and medicine owing to their special properties. However, during TiO2 nanoparticles exposure, nanoparticles may enter the blood circulation and translocate to the heart, and they may result in negative effects on the cardiovascular system. In this study, we demonstrated that the anatase and rutile TiO2 nanoparticles had potential toxicological effects on primary cultured cardiac myocytes of rat. After incubating with the anatase and rutile TiO2 nanoparticles, the primary cultured cardiac myocytes had become elongated and appeared to detach from the surface of cell plate. After exposure to 50, 100, and 150 μg/mL anatase and rutile TiO2 nanoparticles for 2 days, the obvious decrease of cell viability was observed. And further studies showed that TiO2 nanoparticles exposure could induce the high expression of proinflammatory cytokines TNF‐α and IL‐6, especially in 150 μg/mL group. The long‐rod rutile TiO2 had more strong effects on cell viability and proinflammatory cytokines induction than red‐blood cells like anatase TiO2. Results indicated that TiO2 nanoparticles exposure could impair the function of primary cultured cardiac myocytes of rat. Therefore, these findings support the view that much more attention should be aroused on the application of these nanoparticles and their potential exposure effects on human beings.
Full Synchronization Studied by a Set of Partitions Connected Together
Authors: Zhang Jianbao , Ma Zhongjun , Cao Jinde
Published: October 2013

A novel approach is brought forward for synchronization of a clustered network in this paper, the objective of which is twofold. The first one is to study cluster synchronization by analyzing the inner coupling matrices of the individual clusters instead of the one of the whole network. The other is to show that full synchronization can be ensured by several types of cluster synchronization, the partitions of which are connected together. Compared with the classical method for full synchronization, our approach reduces the network size to the cluster size and additionally obtains the thresholds for different types of cluster synchronization. As a numerical example, cluster and full synchronization in a special clustered network are investigated through our approach. It turns out that we obtain the same threshold for full synchronization as the one obtained by the classical method. Numerical simulations confirm the validity of our approach.
The Prevalence and Awareness of Cardiometabolic Risk Factors in Southern Chinese Population with Coronary Artery Disease
Authors: Li Xinrui , Zhang Yuan , Wang Min , Lv Xiaofei , Su Dongfang , Li Zhongxia , Ding Ding , Xia Min , Qiu Jian , Hu Gang , Ling Wenhua
Published: October 2013

Background. Cardiometabolic risk factors significantly accelerate the progression of coronary artery disease (CAD); however, whether CAD patients in South China are aware of the prevalence of these risk factors is not clear yet. Methods. The study consisted of 2312 in‐admission CAD patients from 2008 to 2011 in South China. Disease history including hypertension, dyslipidemia, and diabetes was relied on patients′ self‐reported records. Physical and clinical examinations were tested to assess the real prevalence of the cardiometabolic risk factors. Results. 57.9% of CAD patients had more than 3 cardiometabolic risk factors in terms of the metabolic syndrome. The self‐known and real prevalence of hypertension, diabetes, and dyslipidemia were 56.6%, 28.3%, and 25.1% and 91.3%, 40.9%, and 92.0%, respectively. The awareness rates were 64.4%, 66.3%, and 28.5% for hypertension, diabetes, and dyslipidemia. The prevalence of cardiometabolic risk factors was significantly different among gender and among disease status. Conclusions. Most CAD patients in South China had more than three cardiometabolic risk factors. However, the awareness rate of cardiometabolic diseases was low, especially for dyslipidemia. Strategies of routine physical examination programs are needed for the early detection and treatment of cardiometabolic risk factors in order to prevent CAD progression and prognosis.
Evidence and Search for Sterile Neutrinos at Accelerators
Authors: Louis W. C.
Published: October 2013

The LSND short-baseline neutrino experiment has published evidence for antineutrino oscillations at a mass scale of ~1 eV2. The MiniBooNE experiment, designed to test this evidence for oscillations at an order of magnitude higher neutrino energy and distance, observes excesses of events in both neutrino mode and antineutrino mode. While the MiniBooNE neutrino excess has a neutrino energy spectrum that is softer than expected from LSND, the MiniBooNE antineutrino excess is consistent with neutrino oscillations and with the LSND oscillation signal. When combined with oscillation measurements at the solar and atmospheric mass scales, assuming that the LSND and MiniBooNE signals are due to neutrino oscillations, these experiments imply the existence of more than three neutrino mass states and, therefore, one or more sterile neutrinos. Such sterile neutrinos, if proven to exist, would have a big impact on particle physics, nuclear physics, and astrophysics and would contribute to the dark matter of the universe. Future experiments under construction or proposed at Fermilab, ORNL, CERN, and in Japan will provide a definitive test of short-baseline neutrino oscillations and will have the capability of proving the existence of sterile neutrinos.
Existence and Controllability Results for Nonlocal Fractional Impulsive Differential Inclusions in Banach Spaces
Authors: Wang JinRong , Ibrahim Ahmed G.
Published: October 2013

We firstly deal with the existence of mild solutions for nonlocal fractional impulsive semilinear differential inclusions involving Caputo derivative in Banach spaces in the case when the linear part is the infinitesimal generator of a semigroup not necessarily compact. Meanwhile, we prove the compactness property of the set of solutions. Secondly, we establish two cases of sufficient conditions for the controllability of the considered control problems.
Effect ofJatropha curcasPeptide Fractions on the Angiotensin I-Converting Enzyme Inhibitory Activity
Authors: Segura-Campos Maira R. , Peralta-González Fanny , Castellanos-Ruelas Arturo , Chel-Guerrero Luis A. , Betancur-Ancona David A.
Published: October 2013

Hypertension is one of the most common worldwide diseases in humans. Angiotensin I-converting enzyme (ACE) plays an important role in regulating blood pressure and hypertension. An evaluation was done on the effect of Alcalase hydrolysis of defattedJatropha curcaskernel meal on ACE inhibitory activity in the resulting hydrolysate and its purified fractions. Alcalase exhibited broad specificity and produced a protein hydrolysate with a 21.35% degree of hydrolysis and 34.87% ACE inhibition. Ultrafiltration of the hydrolysate produced peptide fractions with increased biological activity (24.46–61.41%). Hydrophobic residues contributed substantially to the peptides’ inhibitory potency. The 5–10 and <1 kDa fractions were selected for further fractionation by gel filtration chromatography. ACE inhibitory activity (%) ranged from 22.66 to 45.96% with the 5–10 kDa ultrafiltered fraction and from 36.91 to 55.83% with the <1 kDa ultrafiltered fraction. The highest ACE inhibitory activity was observed inF2 ( μg/mL) from the 5–10 kDa fraction andF1 ( μg/mL) from the <1 kDa fraction. ACE inhibitory fractions fromJatrophakernel have potential applications in alternative hypertension therapies, adding a new application for theJatrophaplant protein fraction and improving the financial viability and sustainability of a Jatropha-based biodiesel industry.
Oligomannose-Coated Liposome as a Novel Adjuvant for the Induction of Cellular Immune Responses to Control Disease Status
Authors: Kojima Naoya , Ishii Mariko , Kawauchi Yoko , Takagi Hideaki
Published: October 2013

Professional phagocytic cells, such as dendritic cells, are mainly responsible for phagocytosis, antigen presentation, and cytokine secretion, which induce subsequent activation of T cell-mediated immunity. Thus, strategies that deliver antigens and stimulatory signals to the cells have significant implications for vaccine design. In this paper, we summarize the potential for liposomes coated with the neoglycolipids containing oligomannose residues (OMLs) as a novel adjuvant for induction of Th1 immune responses and CTLs specific for the encased antigen. OMLs preferentially take up peripheral phagocytic cells. In response to OML uptake, the cells secrete IL-12 selectively, enhance the expression of costimulatory molecules, and migrate into lymphoid tissues from peripheral tissues. OMLs also have the ability to deliver encapsulated protein antigens to the MHC class I and class II pathways to generate antigen-specific CTLs and Th1 cells, respectively, and lipid antigen to CD1d to activate NKT cells. Since administration of OML-based vaccines can eliminate an established tumor, inhibit elevation of the serum IgE level, and prevent progression of protozoan infections in several murine, human, and bovine models, OML-based vaccines have revealed their potential for clinical use in vaccination for a variety of diseases in which CTLs and/or Th1 cells act as effector cells.