Science.gov

Sample records for reactively scattered products

  1. Quantum state-resolved reactive scattering of FCH4\\HF,,v,J...CH3: Nascent HF,,v,J... product state distributions

    E-print Network

    Nizkorodov, Sergey

    in solving the quantum reactive scattering problem in more than 3 internal degrees of freedom. Nevertheless parallel advances in both state- of-the-art experiments1­8 and theory,9­13 in particular the ability to i

  2. State-to-state dynamics of high-n Rydberg H-atom scattering with H2: inelastic scattering and reactive scattering.

    PubMed

    Yu, Shengrui; Su, Shu; Dai, Dongxu; Yuan, Kaijun; Yang, Xueming

    2015-04-21

    The state-to-state dynamics of high-n Rydberg H-atom scattering with para-H2 at the collision energies of 0.45 and 1.07 eV have been studied using the H-atom Rydberg tagging time-of-flight technique. Both the inelastic scattering and reactive scattering are observed in the experimental time-of-flight spectra. The products H2(v', j' = odd) come only from reactive scattering and present clearly forward-backward asymmetric angular distributions, which differ from those of the corresponding ion-molecule reaction. The products H2(v', j' = even), however, come from both reactive scattering and inelastic scattering. Simulating the rotational distribution from reactive scattering, we found that most of the H2(v', j' = even) products come from inelastic scattering. The angular distributions of the product H2(v', j' = even) are consistent with what is predicted by the conventional textbook mechanism of inelastic scattering, and are a little different from those of the corresponding ion-molecule inelastic scattering. These results suggest that the effect of Rydberg electron could not be neglected in describing the differential cross sections of H* + para-H2 scattering. From the simulation, the branching ratios of the inelastic scattering channel were determined to be 66% and 79% at the collision energies of 0.45 and 1.07 eV, respectively. PMID:25162182

  3. The mutual influence of reactive and non-reactive scattering channels in atom--molecule collisions.

    NASA Astrophysics Data System (ADS)

    Simbotin, I.; Côté, R.; Dalgarno, A.

    2008-05-01

    In this work, we study D+H2 collisions for the main purpose of understanding the influence of the reactive scattering channels on the non-reactive scattering channels. We will present a detailed quantitative comparison between the results of full calculations (including rearrangement) and non-reactive calculations. We perform this comparison by artificially eliminating the possibility of rearrangement and by allowing only for inelastic scattering.

  4. State-to-state inelastic and reactive molecular beam scattering from surfaces

    SciTech Connect

    Lykke, K.R. ); Kay, B.D. )

    1990-01-01

    Resonantly enhanced multiphoton ionization (REMPI) laser spectroscopic and molecular beam-surface scattering techniques are coupled to study inelastic and reactive gas-surface scattering with state-to-state specificity. Rotational, vibrational, translational and angular distributions have been measured for the inelastic scattering of HCI and N {sub 2} from Au(111). In both cases the scattering is direct-inelastic in nature and exhibits interesting dynamical features such as rotational rainbow scattering. In an effort to elucidate the dynamics of chemical reactions occurring on surfaces we have extended our quantum-resolved scattering studies to include the reactive scattering of a beam of gas phase H-atoms from a chlorinated metal surface M-CI. The nascent rotational and vibrational distributions of the HCI product are determined using REMPI. The thermochemistry for this reaction on Au indicates that the product formation proceeding through chemisorbed H-atoms is slightly endothermic while direct reaction of a has phase H-atom with M-CI is highly exothermic (ca. 50 kcal/mole). Details of the experimental techniques, results and implications regarding the scattering dynamics are discussed. 55 ref., 8 fig.

  5. Inelastic and reactive scattering of hyperthermal atomic oxygen from amorphous carbon

    NASA Technical Reports Server (NTRS)

    Minton, Timothy K.; Nelson, Christine M.; Brinza, David E.; Liang, Ranty H.

    1991-01-01

    The reaction of hyperthermal oxygen atoms with an amorphous carbon-13 surface was studied using a modified universal crossed molecular beams apparatus. Time-of-flight distributions of inelastically scattered O-atoms and reactively scattered CO-13 and CO2-13 were measured with a rotatable mass spectrometer detector. Two inelastic scattering channels were observed, corresponding to a direct inelastic process in which the scattered O-atoms retain 20 to 30 percent of their initial kinetic energy and to a trapping desorption process whereby O-atoms emerge from the surface at thermal velocities. Reactive scattering data imply the formation of two kinds of CO products, slow products whose translational energies are determined by the surface temperature and hyperthermal (Approx. 3 eV) products with translational energies comprising roughly 30 percent of the total available energy (E sub avl), where E sub avl is the sum of the collision energy and the reaction exothermicity. Angular data show that the hyperthermal CO is scattered preferentially in the specular direction. CO2 product was also observed, but at much lower intensities than CO and with only thermal velocities.

  6. Modern integral equation techniques for quantum reactive scattering theory

    SciTech Connect

    Auerbach, S.M.

    1993-11-01

    Rigorous calculations of cross sections and rate constants for elementary gas phase chemical reactions are performed for comparison with experiment, to ensure that our picture of the chemical reaction is complete. We focus on the H/D+H{sub 2} {yields} H{sub 2}/DH + H reaction, and use the time independent integral equation technique in quantum reactive scattering theory. We examine the sensitivity of H+H{sub 2} state resolved integral cross sections {sigma}{sub v{prime}j{prime},vj}(E) for the transitions (v = 0,j = 0) to (v{prime} = 1,j{prime} = 1,3), to the difference between the Liu-Siegbahn-Truhlar-Horowitz (LSTH) and double many body expansion (DMBE) ab initio potential energy surfaces (PES). This sensitivity analysis is performed to determine the origin of a large discrepancy between experimental cross sections with sharply peaked energy dependence and theoretical ones with smooth energy dependence. We find that the LSTH and DMBE PESs give virtually identical cross sections, which lends credence to the theoretical energy dependence.

  7. CLASSIFICATION AND REACTIVITY OF SECONDARY ALUMINUM PRODUCTION WASTE

    E-print Network

    in the ASCE Journal of Hazardous, Toxic, and Radioactive Waste November 8, 2012 #12;2 ClassificationCLASSIFICATION AND REACTIVITY OF SECONDARY ALUMINUM PRODUCTION WASTE Navid H. Jafari Student Member and Reactivity of Secondary Aluminum Production Waste1 Navid H. Jafari1 , Timothy D. Stark2 and Ralph Roper3 2 3

  8. Production and Consumption of Reactive Oxygen Species by Fullerenes

    EPA Science Inventory

    Reactive oxygen species (ROS) are one of the most important intermediates in chemical, photochemical, and biological processes. To understand the environmental exposure and toxicity of fullerenes better, the production and consumption of ROS (singlet oxygen, superoxide, hydrogen ...

  9. Production of reactive sintered nickel aluminide

    SciTech Connect

    1995-10-01

    This is the final report pertaining to the development of aluminides by reactive synthesis. Included in this report is an overview of results during the scope of this effort, details on specific task accomplishments, and a summary of customer evaluations. Opportunities for future work are also included at the end of this report.

  10. Reactive scattering theory for molecular transitions in time-dependent fields

    E-print Network

    Miller, William H.

    time-dependent perturbation theory. Bound-to-bound i.e., photoexcitation and bound-to-continuum i in an extended Hilbert space with an additional time-coordinate, t .4­7 New computational algorithms wereReactive scattering theory for molecular transitions in time-dependent fields Uri Peskin

  11. Reactive Phosphorus Removal from Aquaculture and Poultry Productions

    E-print Network

    Rubloff, Gary W.

    Reactive Phosphorus Removal from Aquaculture and Poultry Productions Systems Using Polymeric and poultry production wastewater effluents. The sorbent used was a cross-linked polyamine (PAA,HCl) polymeric poultry and aquaculture wastewater effluents. Upon treatment, phosphorus anion concentrations were reduced

  12. Light scattering measurement of sodium polyacrylate products

    NASA Astrophysics Data System (ADS)

    Lama, Nisha; Norwood, David; Boone, Steven; Massie-Boyer, Valerie

    2015-03-01

    In the presentation, we will describe the use of a multi-detector HPLC incorporating the DAWN EOS multi-angle laser light scattering (MALLS) detector to measure the properties such as molecular weight, RMS radius, contour and persistence length and polydispersity of sodium polyacrylate products. The samples of sodium polyacrylate are used in various industries as thickening agents, coating dispersants, artificial snow, laundry detergent and disposable diapers. Data and results obtained from the experiment will be presented.

  13. Production of reactive sintered nickel aluminide

    SciTech Connect

    Cooper, R.M.

    1993-01-01

    Effort over the past 3 months was directed at increasing manufacturing capacity (ball milling) and improving product quality. Orders for the powder have increased, mainly for plasma spray powders. NiAl is an excellent coat between a metal and a ceramic, and its use instead of cobalt should extending operating range for carbide tools. The feather phase in the sintered Ni[sub 3]Al was identified to be a Ni-rich phase nucleated on the grain boundaries with 10 wt % Al composition. The ductile to brittle temperature of powder extruded NiAl was found to be between 500 and 600 C, and shows a 50% elongation at 600 C.

  14. Reactivity margins in heavy water moderated production reactors

    SciTech Connect

    Benton, F.D.

    1981-11-01

    The design of the reactor core and components of the heavy water moderated reactors at the Savannah River Plant (SFP) can be varied to produce a number of isotopes. For the past decade, the predominant reactor core design has been the enriched-depleted lattice. In this lattice, fuel assemblies of highly enriched uranium and target assemblies of depleted uranium, which produce plutonium, occupy alternate lattice positions. This heterogeneous lattice arrangement and a nonuniform control rod distribution result in a reactor core that requires sophisticated calculational methods for accurate reactivity margin and power distribution predictions. For maximum accuracy, techniques must exist to provide a base of observed data for the calculations. Frequent enriched-depleted lattice design changes are required as product demands vary. These changes provided incentive for the development of techniques to combine the results of calculations and observed reactivity data to accurately and conveniently monitor reactivity margins during operation.

  15. Reactivity effects of fission product decay in PWRs

    SciTech Connect

    Aragones, J.M.; Ahnert, C.

    1988-01-01

    The purpose of the work reported in this paper is to analyze the effects of fission product chains with radioactive decay on the reactivity in pressurized water reactor (PWR) cores, calculating their accumulation and absorption rates along fuel burnup at continuous operation and after shutdown periods extending from 1 day to a few months. The authors PWR version of the WIMS-D4 code is first used to obtain the individual number densities, absorption rates, and averaged cross sections for every nuclide of the fission product chains with significant decay rates, as a function of fuel burnup at continuous irradiation. Next, by an auxiliary ad hoc code, these data, have been processed together with the required one for fissile nuclides and boron, also taken from WIMS at each burnup step, to calculate the average or effective values relevant for the analysis and the decay and change in overall absorption after several shutdown times. (1) The reactivity effect of fission product decay changes significantly with the shutdown time. The maximum absorption increase by decay is reached in /approx/ 10 days' shutdown. (2) The dependence with fuel type, enrichment, and burnup is slight, but the change with previous power density is nearly linear, which might be significant after coast-down in previous cycles. (3) For long shutdown periods, the overall reactivity effect of decay in the three fission product chains considered is much less than if only the samarium peak due to /sup 149/Nd is considered.

  16. Reactive ion etching-assisted surface-enhanced Raman scattering measurements on the single nanoparticle level

    SciTech Connect

    Wang, Si-Yi; Jiang, Xiang-Xu; Wei, Xin-Pan; Lee, Shuit-Tong E-mail: yaohe@suda.edu.cn; He, Yao E-mail: yaohe@suda.edu.cn; Xu, Ting-Ting

    2014-06-16

    Single-nanoparticle surface-enhanced Raman scattering (SERS) measurement is of essential importance for both fundamental research and practical applications. In this work, we develop a class of single-particle SERS approaches, i.e., reactive ion etching (RIE)-assisted SERS measurements correlated with scanning electron microscopy (SEM) strategy (RIE/SERS/SEM), enabling precise and high-resolution identification of single gold nanoparticle (AuNP) in facile and reliable manners. By using AuNP-coated silicon wafer and quartz glass slide as models, we further employ the developed RIE/SERS/SEM method for interrogating the relationship between SERS substrates and enhancement factor (EF) on the single particle level. Together with theoretical calculation using an established finite-difference-time-domain (FDTD) method, we demonstrate silicon wafer as superior SERS substrates, facilitating improvement of EF values.

  17. Transition state dynamics of O( 3P) + H2S reactive scattering

    NASA Astrophysics Data System (ADS)

    Zhu, Z. Z.; McDouall, J. J. W.; Smith, D. J.; Grice, R.

    1992-01-01

    A simple model is proposed for the direct rebound dynamics of O( 3P) atoms reacting with H 2S molecules whereby an H atom is displaced at a bending angle ? with respect to the direction of the OS axis of the triplet H 2SO transition state. Comparison with the recent angular distribution measurements of HSO reactive scattering by Casavecchia et al. at an initial translational energy E = 50 kJ mol -1, suggests that the bending angle lies in the range ? = 60° ± 10°, where ? = 0° refers to the collinear OSH configuration. Ab initio calculations indicate a more strongly bent transition state which is initially pyramidal but passes through a planar configuration before dissociating, with the bending angle decreasing from ? ? 96° to ? ? 80°. Excitation of both the HSH bending and asymmetric stretch modes of the transition state results in final dissociation through less strongly bent configurations.

  18. Reactive oxygen species in bovine embryo in vitro production.

    PubMed

    Dalvit, G C; Cetica, P D; Pintos, L N; Beconi, M T

    2005-08-01

    Oxidative modifications of cell components due to the action of reactive oxygen species (ROS) is one of the most potentially damaging processes for proper cell function. However, in the last few years it has been observed that ROS participate in physiological processes. The aim of this work was to determine ROS generation during in vitro production of bovine embryos. Cumulus-oocyte complexes were recovered by aspiration of antral follicles from ovaries obtained from slaughtered cows and cultured in medium 199 for 22 h at 39 degrees C in 5% CO2: 95% humidified air. In vitro fertilization was carried out in IVF-mSOF with frozen-thawed semen in the same culture conditions and embryo in vitro culture in IVC-mSOF at 90% N2: 5% CO2: 5% O2. ROS was determined in denuded oocytes and embryos at successive stages of development by the 2',7'-dichlorodihydrofluorescein diacetate fluorescent assay. ROS production was not modified during oocyte maturation. However, a gradual increase in ROS production was observed up to the late morula stage during embryo in vitro culture (P < 0.05). In expanded blastocysts, ROS level decreased to reach values similar to the corresponding in oocytes. In the bovine species, the variation in ROS level during the complete process of embryo in vitro production was determined for the first time. PMID:16187501

  19. Kinetic analysis of phagosomal production of reactive oxygen species.

    PubMed

    Tlili, Asma; Dupré-Crochet, Sophie; Erard, Marie; Nüsse, Oliver

    2011-02-01

    Phagocytes produce large quantities of reactive oxygen species for pathogen killing; however, the kinetics and amplitude of ROS production on the level of individual phagosomes are poorly understood. This is mainly due to the lack of appropriate methods for quantitative ROS detection with microscopic resolution. We covalently attached the ROS-sensitive dye dichlorodihydrofluorescein (DCFH(2)) to yeast particles and investigated their fluorescence due to oxidation in vitro and in live phagocytes. In vitro, the dye was oxidized by H(2)O(2) plus horseradish peroxidase but also by HOCl. The latter produced a previously unrecognized oxidation product with red-shifted excitation and emission spectra and a characteristic difference in the shape of the excitation spectrum near 480 nm. Millimolar HOCl bleached the DCFH(2) oxidation products. Inside phagosomes, DCFH(2)-labeled yeast were oxidized for several minutes in a strictly NADPH oxidase-dependent manner as shown by video microscopy. Inhibition of the NADPH oxidase rapidly stopped the fluorescence increase of the particles. At least two characteristic kinetics of oxidation were distinguished and the variability of DCFH(2) oxidation in phagosomes was much larger than the variability upon oxidation in vitro. We conclude that DCFH(2)-yeast is a valuable tool to investigate the kinetics and amplitude of ROS production in individual phagosomes. PMID:21111807

  20. A MATLAB-based finite-element visualization of quantum reactive scattering. I. Collinear atom-diatom reactions

    SciTech Connect

    Warehime, Mick; Alexander, Millard H.

    2014-07-14

    We restate the application of the finite element method to collinear triatomic reactive scattering dynamics with a novel treatment of the scattering boundary conditions. The method provides directly the reactive scattering wave function and, subsequently, the probability current density field. Visualizing these quantities provides additional insight into the quantum dynamics of simple chemical reactions beyond simplistic one-dimensional models. Application is made here to a symmetric reaction (H+H{sub 2}), a heavy-light-light reaction (F+H{sub 2}), and a heavy-light-heavy reaction (F+HCl). To accompany this article, we have written a MATLAB code which is fast, simple enough to be accessible to a wide audience, as well as generally applicable to any problem that can be mapped onto a collinear atom-diatom reaction. The code and user's manual are available for download from http://www2.chem.umd.edu/groups/alexander/FEM.

  1. A MATLAB-based finite-element visualization of quantum reactive scattering. I. Collinear atom-diatom reactions.

    PubMed

    Warehime, Mick; Alexander, Millard H

    2014-07-14

    We restate the application of the finite element method to collinear triatomic reactive scattering dynamics with a novel treatment of the scattering boundary conditions. The method provides directly the reactive scattering wave function and, subsequently, the probability current density field. Visualizing these quantities provides additional insight into the quantum dynamics of simple chemical reactions beyond simplistic one-dimensional models. Application is made here to a symmetric reaction (H+H2), a heavy-light-light reaction (F+H2), and a heavy-light-heavy reaction (F+HCl). To accompany this article, we have written a MATLAB code which is fast, simple enough to be accessible to a wide audience, as well as generally applicable to any problem that can be mapped onto a collinear atom-diatom reaction. The code and user's manual are available for download from http://www2.chem.umd.edu/groups/alexander/FEM. PMID:25028010

  2. Enzymatic Production of Extracellular Reactive Oxygen Species by Marine Microorganisms

    NASA Astrophysics Data System (ADS)

    Diaz, J. M.; Andeer, P. F.; Hansel, C. M.

    2014-12-01

    Reactive oxygen species (ROS) serve as intermediates in a myriad of biogeochemically important processes, including cell signaling pathways, cellular oxidative stress responses, and the transformation of both nutrient and toxic metals such as iron and mercury. Abiotic reactions involving the photo-oxidation of organic matter were once considered the only important sources of ROS in the environment. However, the recent discovery of substantial biological ROS production in marine systems has fundamentally shifted this paradigm. Within the last few decades, marine phytoplankton, including diatoms of the genus Thalassiosira, were discovered to produce ample extracellular quantities of the ROS superoxide. Even more recently, we discovered widespread production of extracellular superoxide by phylogenetically and ecologically diverse heterotrophic bacteria at environmentally significant levels (up to 20 amol cell-1 hr-1), which has introduced the revolutionary potential for substantial "dark" cycling of ROS. Despite the profound biogeochemical importance of extracellular biogenic ROS, the cellular mechanisms underlying the production of this ROS have remained elusive. Through the development of a gel-based assay to identify extracellular ROS-producing proteins, we have recently found that enzymes typically involved in antioxidant activity also produce superoxide when molecular oxygen is the only available electron acceptor. For example, large (~3600 amino acids) heme peroxidases are involved in extracellular superoxide production by a bacterium within the widespread Roseobacter clade. In Thalassiosira spp., extracellular superoxide is produced by flavoproteins such as glutathione reductase and ferredoxin NADP+ reductase. Thus, extracellular ROS production may occur via secreted and/or cell surface enzymes that modulate between producing and degrading ROS depending on prevailing geochemical and/or ecological conditions.

  3. Towards a specific reaction parameter density functional for reactive scattering of H2 from Pd(111)

    NASA Astrophysics Data System (ADS)

    Boereboom, J. M.; Wijzenbroek, M.; Somers, M. F.; Kroes, G. J.

    2013-12-01

    Recently, an implementation of the specific reaction parameter (SRP) approach to density functional theory (DFT) was used to study several reactive scattering experiments of H2 on Cu(111). It was possible to obtain chemical accuracy (1 kcal/mol ? 4.2 kJ/mol), and therefore, accurately model this paradigmatic example of activated H2 dissociation on a metal surface. In this work, the SRP-DFT methodology is applied to the dissociation of hydrogen on a Pd(111) surface, in order to test whether the SRP-DFT approach is also applicable to non-activated H2-metal systems. In the calculations, the Born-Oppenheimer static surface approximations are used. A comparison to molecular beam sticking experiments, performed at incidence energies ?125 meV, on H2 + Pd(111) suggested the PBE-vdW [where the Perdew, Burke, and Ernzerhof (PBE) correlation is replaced by van der Waals correlation] functional as a candidate SRP density functional describing the reactive scattering of H2 on Pd(111). Unfortunately, quantum dynamics calculations are not able to reproduce the molecular beam sticking results for incidence energies <125 meV. From a comparison to initial state-resolved (degeneracy averaged) sticking probabilities it seems clear that for H2 + Pd(111) dynamic trapping and steering effects are important, and that these effects are not yet well modeled with the potential energy surfaces considered here. Applying the SRP-DFT method to systems where H2 dissociation is non-activated remains difficult. It is suggested that a density functional that yields a broader barrier distribution and has more non-activated pathways than PBE-vdW (i.e., non-activated dissociation at some sites but similarly high barriers at the high energy end of the spectrum) should allow a more accurate description of the available experiments. Finally, it is suggested that new and better characterized molecular beam sticking experiments be done on H2 + Pd(111), to facilitate the development of a more accurate theoretical description of this system.

  4. Comparison of Alternative Control Structures for an Ideal Two-Product Reactive Distillation Column

    E-print Network

    Al-Arfaj, Muhammad A.

    Comparison of Alternative Control Structures for an Ideal Two-Product Reactive Distillation Column distillation columns have been explored in many papers, very few papers have dealt with closed-loop control. Most of these control papers consider reactive distillation columns in which there is only one product

  5. Orientation and state-selection of hydroxyl radicals by electric hexapole focusing - applications in reactive surface scattering.

    NASA Astrophysics Data System (ADS)

    Curtiss, Thomas J.; Backstrand, Kyle M.; Hain, Toby D.; Weibel, Michael A.

    1997-03-01

    Hydroxyl radicals generated in a corona-discharge free jet expansion have been focused and rotationally state-selected with an electrostatic hexapole. Tuning the hexapole resonance voltage selectively focused either of two populated |J ? M_J> states onto a scattering target, either the |3/2 3/2 3/2> state or the |3/2 3/2 1/2> state. Trajectory calculations reproduce experimental focusing spectra for OH and OD seeded in He and Ar well. We will report results from work in progress on reactive scattering studies exploring the oxygen / hydrogen / platinum catalysis system. abstract.

  6. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings Pt. 59, Subpt. E, Table 1 Table 1 to Subpart E of Part 59—Product-Weighted Reactivity Limits by...

  7. In situ reactive oxygen species production for tertiary wastewater treatment.

    PubMed

    Guitaya, Léa; Drogui, Patrick; Blais, Jean François

    2015-05-01

    The goal of this research was to develop a new approach for tertiary water treatment, particularly disinfection and removal of refractory organic compounds, without adding any chemical. Hydrogen peroxide can indeed be produced from dissolved oxygen owing to electrochemical processes. Using various current intensities (1.0 to 4.0 A), it was possible to in situ produce relatively high concentration of H2O2 with a specific production rate of 0.05?×?10(-5) M/min/A. Likewise, by using ultraviolet-visible absorption spectroscopy method, it was shown that other reactive oxygen species (ROS) including HO(*) radical and O3 could be simultaneously formed during electrolysis. The ROS concentration passed from 0.45?×?10(-5) M after 20 min of electrolysis to a concentration of 2.87?×?10(-5) M after 100 min of electrolysis. The disinfection and the organic matter removal were relatively high during the tertiary treatment of municipal and domestic wastewaters. More than 90 % of organic compounds (chemical oxygen demand) can be removed, whereas 99 % of faecal coliform abatement can be reached. Likewise, the process was also effective in removing turbidity (more than 90 % of turbidity was removed) so that the effluent became more and more transparent. PMID:25483973

  8. Molten salt extraction of transuranic and reactive fission products from used uranium oxide fuel

    DOEpatents

    Herrmann, Steven Douglas

    2014-05-27

    Used uranium oxide fuel is detoxified by extracting transuranic and reactive fission products into molten salt. By contacting declad and crushed used uranium oxide fuel with a molten halide salt containing a minor fraction of the respective uranium trihalide, transuranic and reactive fission products partition from the fuel to the molten salt phase, while uranium oxide and non-reactive, or noble metal, fission products remain in an insoluble solid phase. The salt is then separated from the fuel via draining and distillation. By this method, the bulk of the decay heat, fission poisoning capacity, and radiotoxicity are removed from the used fuel. The remaining radioactivity from the noble metal fission products in the detoxified fuel is primarily limited to soft beta emitters. The extracted transuranic and reactive fission products are amenable to existing technologies for group uranium/transuranic product recovery and fission product immobilization in engineered waste forms.

  9. Production of Charged Hadrons in Muon Deep Inelastic Scattering

    E-print Network

    Mohammed Sultan Al-Buriahi; Mohammed Tarek Hussein; Mohammed Tawfik Ghoneim

    2015-08-06

    The production of charged hadrons, in muon Deep inelastic scattering (DIS), at light and heavy target is presented. The particles produced by the interaction with Xenon (Xe) is compared with that produced by the interaction with Deuteron (D), to obtain information on cascading process, forward-backward productions, and the rapidity distribution in different bins of the invariant mass of the interacting system W.

  10. Production of Charged Hadrons in Muon Deep Inelastic Scattering

    E-print Network

    Al-Buriahi, Mohammed Sultan; Ghoneim, Mohammed Tawfik

    2015-01-01

    The production of charged hadrons, in muon Deep inelastic scattering (DIS), at light and heavy target is presented. The particles produced by the interaction with Xenon (Xe) is compared with that produced by the interaction with Deuteron (D), to obtain information on cascading process, forward-backward productions, and the rapidity distribution in different bins of the invariant mass of the interacting system W.

  11. Reactive oxygen species production by catechol stabilized copper nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Cheng; Ahmed, Ishtiaq; Fruk, Ljiljana

    2013-11-01

    Stable Cu nanoparticles (NPs) prepared using catechol containing dopamine-based linkers could generate reactive oxygen species (ROS) that can activate peroxidase enzymes and catalyze the degradation of fluorescent dye pollutants.Stable Cu nanoparticles (NPs) prepared using catechol containing dopamine-based linkers could generate reactive oxygen species (ROS) that can activate peroxidase enzymes and catalyze the degradation of fluorescent dye pollutants. Electronic supplementary information (ESI) available: Details of the synthesis of dopamine linkers and Cu NPs, peroxidase activity tests, H2O2 calibration and degradation tests for resorufin, RB and MB. See DOI: 10.1039/c3nr03563h

  12. Leptoquark Pair Production in ??Scattering: Threshold Resummation

    E-print Network

    Johannes Blümlein; Alexandre Kryukov

    2000-08-10

    The possibilities to pair-produce leptoquarks in photon-photon collisions are discussed. QCD threshold corrections lead to a strong enhancement of the production cross section. Suitably long-lived leptoquarks ($\\Gamma_\\Phi \\lsim 100 \\MeV$) may form Leptoquarkonium states.

  13. Solar light-induced production of reactive oxygen species by single walled carbon nanotubes in water

    EPA Science Inventory

    Photosensitizing processes of engineered nanomaterials (ENMs) which include photo-induced production of reactive oxygen species (ROS) convert light energy into oxidizing chemical energy that mediates transformations of nanomaterials. The oxidative stress associated with ROS may p...

  14. Fullerol-sensitized production of reactive oxygen species in aqueous solution.

    PubMed

    Pickering, K D; Wiesner, M R

    2005-03-01

    The relative production rate of reactive oxygen in aqueous solution sensitized by fullerol (a polyhydroxylated, water-soluble form of the fullerene C60) was measured and compared to known reactive oxygen sensitizers using an oxygen consumption method. The solutions were irradiated by polychromatic visible and ultraviolet light. Reactive oxygen species were generated under both visible and ultraviolet light sources. The greatest rates of oxygen consumption were observed at acidic pH. We show for the first time evidence of both singlet oxygen and superoxide production by fullerol under both UV and polychromatic light sources. PMID:15787378

  15. Atmospheric OH reactivity in central London: observations, model predictions and estimates of in situ ozone production

    NASA Astrophysics Data System (ADS)

    Whalley, L. K.; Stone, D.; Bandy, B.; Dunmore, R.; Hamilton, J. F.; Hopkins, J.; Lee, J. D.; Lewis, A. C.; Heard, D. E.

    2015-11-01

    Near-continuous measurements of OH reactivity in the urban background atmosphere of central London during the summer of 2012 are presented. OH reactivity behaviour is seen to be broadly dependent on airmass origin with the highest reactivity and the most pronounced diurnal profile observed when air had passed over central London to the East, prior to measurement. Averaged over the entire observation period of 26 days, OH reactivity peaked at ~ 27 s-1 in the morning with a minimum of ~ 15 s-1 during the afternoon. A maximum OH reactivity of 116 s-1 was recorded on one day during morning rush hour. A detailed box model using the Master Chemical Mechanism was used to calculate OH reactivity, and was constrained with an extended measurement dataset of volatile organic compounds (VOCs) derived from GC-FID and a two-dimensional GC instrument which included heavier molecular weight (up to C12) aliphatic VOCs, oxygenated VOCs and the biogenic VOCs of ? pinene and limonene. Comparison was made between observed OH reactivity and modelled OH reactivity using (i) a standard suite of VOC measurements (C2-C8 hydrocarbons and a small selection of oxygenated VOCs) and (ii) a more comprehensive inventory including species up to C12. Modelled reactivities were lower than those measured (by 33 %) when only the reactivity of the standard VOC suite was considered. The difference between measured and modelled reactivity was improved, to within 15 %, if the reactivity of the higher VOCs (≥ C9) was also considered, with the reactivity of the biogenic compounds of ? pinene and limonene and their oxidation products almost entirely responsible for this improvement. Further improvements in the model's ability to reproduce OH reactivity (to within 6 %) could be achieved if the reactivity and degradation mechanism of unassigned two-dimensional GC peaks were estimated. Neglecting the contribution of the higher VOCs (≥ C9) (particularly ? pinene and limonene) and model-generated intermediates worsened the agreement between modelled and observed OH concentrations (by 41 %) and the magnitude of in situ ozone production calculated from the production of RO2 was significantly lower (60 %). This work highlights that any future ozone abatement strategies should consider the role that biogenic emissions play alongside anthropogenic emissions in influencing London's air quality.

  16. Double scattering production of two $\\rho^0$ mesons in UPC

    E-print Network

    K?usek-Gawenda, Mariola

    2015-01-01

    We review our recent results for double-scattering mechanism in the exclusive $AA \\to AA \\rho^0\\rho^0$ reaction in ultrarelativistic ultraperipheral heavy ion collisions. The cross section for single and double-$\\rho^0$ production is calculated in the impact parameter space equivalent photon approximation. We compare the results of our calculation with the STAR and ALICE Collaboration results on one $\\rho^0(770)$ meson and four-charged-pion production.

  17. Double scattering production of two $?^0$ mesons in UPC

    E-print Network

    Mariola K?usek-Gawenda; Antoni Szczurek

    2015-09-24

    We review our recent results for double-scattering mechanism in the exclusive $AA \\to AA \\rho^0\\rho^0$ reaction in ultrarelativistic ultraperipheral heavy ion collisions. The cross section for single and double-$\\rho^0$ production is calculated in the impact parameter space equivalent photon approximation. We compare the results of our calculation with the STAR and ALICE Collaboration results on one $\\rho^0(770)$ meson and four-charged-pion production.

  18. Reactivity impact of {sup 16}O thermal elastic-scattering nuclear data for some numerical and critical benchmark systems

    SciTech Connect

    Kozier, K. S.; Roubtsov, D.; Plompen, A. J. M.; Kopecky, S.

    2012-07-01

    The thermal neutron-elastic-scattering cross-section data for {sup 16}O used in various modern evaluated-nuclear-data libraries were reviewed and found to be generally too high compared with the best available experimental measurements. Some of the proposed revisions to the ENDF/B-VII.0 {sup 16}O data library and recent results from the TENDL system increase this discrepancy further. The reactivity impact of revising the {sup 16}O data downward to be consistent with the best measurements was tested using the JENDL-3.3 {sup 16}O cross-section values and was found to be very small in MCNP5 simulations of the UO{sub 2} and reactor-recycle MOX-fuel cases of the ANS Doppler-defect numerical benchmark. However, large reactivity differences of up to about 14 mk (1400 pcm) were observed using {sup 16}O data files from several evaluated-nuclear-data libraries in MCNP5 simulations of the Los Alamos National Laboratory HEU heavy-water solution thermal critical experiments, which were performed in the 1950's. The latter result suggests that new measurements using HEU in a heavy-water-moderated critical facility, such as the ZED-2 zero-power reactor at the Chalk River Laboratories, might help to resolve the discrepancy between the {sup 16}O thermal elastic-scattering cross-section values and thereby reduce or better define its uncertainty, although additional assessment work would be needed to confirm this. (authors)

  19. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Product-Weighted Reactivity Limits by Coating Category 1 Table 1 to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS...

  20. Reactivation of latent herpes simplex virus by adenovirus recombinants encoding mutant IE-0 gene products.

    PubMed Central

    Zhu, X X; Chen, J X; Young, C S; Silverstein, S

    1990-01-01

    We have previously shown that adenovirus recombinants expressing functional ICP0 reactivate latent herpes simplex virus type 2 (HSV-2) in an in vitro latency system. This study demonstrated that ICP0, independent of other HSV gene products, is sufficient to reactivate latent HSV-2 in this in vitro system. To assess the effects of defined mutations in the sequence encoding ICP0 (IE-0) on reactivation, seven in-frame insertion and three in-frame deletion mutants were moved into an adenovirus expression vector. Each recombinant directed the synthesis of stable ICP0 of the correct size. The transactivation activity of the mutated sequences in these recombinants was similar to that when they were tested in plasmids. When these recombinants were examined for their ability to reactivate in the in vitro latency system, mutants with dramatic defects in transactivation (Ad-0/125, Ad-0/89, Ad-0/2/7, and Ad-0/88/93) were unable to reactivate latent HSV-2 independent of the multiplicity of infection. An exception to this correlation was the finding that Ad-0/89, which transactivated poorly, was able to reactivate latent virus after prolonged incubation whereas other transactivation-deficient mutants could not. Moreover, the presence of ICP4 did not compensate for the inability of any of the recombinants tested to reactivate HSV-2. These results show that (i) the transactivation domains of ICP0 are also used in reactivation, (ii) the presence of another essential HSV regulatory protein ICP4 does not alter the pattern of reactivation by ICP0, and (iii) mutations in some regions of IE-0 previously shown to affect viral growth and plaque formation did not alter its ability to reactivate in this in vitro system. Images PMID:2166826

  1. Dijet production in diffractive deep inelastic scattering at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Nuncio-Quiroz, A. E.; Paul, E.; Renner, R.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Blohm, C.; Bonato, A.; Borras, K.; Ciesielski, R.; Coppola, N.; Dossanov, A.; Drugakov, V.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Hüttmann, A.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Borodin, M.; Kozulia, A.; Lisovyi, M.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Y.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Ferrando, J.; Foster, B.; Korcsak-Gorzo, K.; Oliver, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Smith, O.; Stern, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.

    2007-12-01

    The production of dijets in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 61 pb-1. The dijet cross section has been measured for virtualities of the exchanged virtual photon, 5 < Q2 < 100 GeV2, and ?*p centre-of-mass energies, 100 < W < 250 GeV. The jets, identified using the inclusive kT algorithm in the ?*p frame, were required to have a transverse energy E* T,jet > 4 GeV and the jet with the highest transverse energy was required to have E* T,jet > 5 GeV. All jets were required to be in the pseudorapidity range -3.5scattering data.

  2. Probing coal reactivity by time-resolved small angle x-ray scattering.

    SciTech Connect

    Winans, R. E.

    1999-01-22

    The objective of this study is to observe changes in coal structure in situ with small angle X-ray scattering (SAXS) during solvent swelling and during pyrolysis. We have built a SAXS instrument at the Basic Energy Sciences Synchrotrons Research Center at the Advanced Photon Source that allows us to obtain scattering patterns in the millisecond time domain. The eight Argonne Premium Coal samples were used in this study. The information that can be derived from these experiments, such as changes in fractal dimensionality and in size and type of porosity, was found to be very rank-dependent. In the swelling experiments, it was noted that for certain coals, structural changes occurred in just a few minutes.

  3. PRODUCTION OF STARCH GRAFT COPOLYMERS USING REACTIVE EXTRUSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is considerable interest in the use of starch graft copolymers for applications as hydrogels, controlled release, and superabsorbents which involve contact with water. Typical production methods use batch processess at relatively low solids content, which produce large amounts of ungrafted ho...

  4. Measurement of D*± production in deep inelastic scattering at HERA

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Antonelli, S.; Antonioli, P.; Antonov, A.; Arneodo, M.; Arslan, O.; Aushev, V.; Aushev, Y.; Bachynska, O.; Bamberger, A.; Barakbaev, A. N.; Barbagli, G.; Bari, G.; Barreiro, F.; Bartosik, N.; Bartsch, D.; Basile, M.; Behnke, O.; Behr, J.; Behrens, U.; Bellagamba, L.; Bertolin, A.; Bhadra, S.; Bindi, M.; Blohm, C.; Bokhonov, V.; Bold, T.; Boos, E. G.; Borras, K.; Boscherini, D.; Bot, D.; Brock, I.; Brownson, E.; Brugnera, R.; Brümmer, N.; Bruni, A.; Bruni, G.; Brzozowska, B.; Bussey, P. J.; Bylsma, B.; Caldwell, A.; Capua, M.; Carlin, R.; Catterall, C. D.; Chekanov, S.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; Cooper-Sarkar, A. M.; Coppola, N.; Corradi, M.; Corriveau, F.; Costa, M.; D'Agostini, G.; Dal Corso, F.; del Peso, J.; Dementiev, R. K.; De Pasquale, S.; Derrick, M.; Devenish, R. C. E.; Dobur, D.; Dolgoshein, B. A.; Dolinska, G.; Doyle, A. T.; Drugakov, V.; Durkin, L. S.; Dusini, S.; Eisenberg, Y.; Ermolov, P. F.; Eskreys, A.; Fang, S.; Fazio, S.; Ferrando, J.; Ferrero, M. I.; Figiel, J.; Foster, B.; Gach, G.; Galas, A.; Gallo, E.; Garfagnini, A.; Geiser, A.; Gialas, I.; Gizhko, A.; Gladilin, L. K.; Gladkov, D.; Glasman, C.; Gogota, O.; Golubkov, Yu. A.; Göttlicher, P.; Grabowska-Bold, I.; Grebenyuk, J.; Gregor, I.; Grigorescu, G.; Grzelak, G.; Gueta, O.; Guzik, M.; Gwenlan, C.; Haas, T.; Hain, W.; Hamatsu, R.; Hart, J. C.; Hartmann, H.; Hartner, G.; Hilger, E.; Hochman, D.; Hori, R.; Hüttmann, A.; Ibrahim, Z. A.; Iga, Y.; Ingbir, R.; Ishitsuka, M.; Iudin, A.; Jakob, H.-P.; Januschek, F.; Jones, T. W.; Jüngst, M.; Kadenko, I.; Kahle, B.; Kananov, S.; Kanno, T.; Karshon, U.; Karstens, F.; Katkov, I. I.; Kaur, M.; Kaur, P.; Keramidas, A.; Khein, L. A.; Kim, J. Y.; Kisielewska, D.; Kitamura, S.; Klanner, R.; Klein, U.; Koffeman, E.; Kondrashova, N.; Kononenko, O.; Kooijman, P.; Korol, Ie.; Korzhavina, I. A.; Kotanski, A.; Kötz, U.; Kovalchuk, N.; Kowalski, H.; Kuprash, O.; Kuze, M.; Lee, A.; Levchenko, B. B.; Levy, A.; Libov, V.; Limentani, S.; Ling, T. Y.; Lisovyi, M.; Lobodzinska, E.; Lohmann, W.; Löhr, B.; Lohrmann, E.; Long, K. R.; Longhin, A.; Lontkovskyi, D.; Lukina, O. Yu.; Maeda, J.; Magill, S.; Makarenko, I.; Malka, J.; Mankel, R.; Margotti, A.; Marini, G.; Martin, J. F.; Mastroberardino, A.; Mattingly, M. C. K.; Melzer-Pellmann, I.-A.; Mergelmeyer, S.; Miglioranzi, S.; Mohamad Idris, F.; Monaco, V.; Montanari, A.; Morris, J. D.; Mujkic, K.; Musgrave, B.; Nagano, K.; Namsoo, T.; Nania, R.; Nigro, A.; Ning, Y.; Nobe, T.; Notz, D.; Nowak, R. J.; Nuncio-Quiroz, A. E.; Oh, B. Y.; Okazaki, N.; Olkiewicz, K.; Onishchuk, Yu.; Papageorgiu, K.; Parenti, A.; Paul, E.; Pawlak, J. M.; Pawlik, B.; Pelfer, P. G.; Pellegrino, A.; Perlanski, W.; Perrey, H.; Piotrzkowski, K.; Plucinski, P.; Pokrovskiy, N. S.; Polini, A.; Proskuryakov, A. S.; Przybycien, M.; Raval, A.; Reeder, D. D.; Reisert, B.; Ren, Z.; Repond, J.; Ri, Y. D.; Robertson, A.; Roloff, P.; Rubinsky, I.; Ruspa, M.; Sacchi, R.; Samson, U.; Sartorelli, G.; Savin, A. A.; Saxon, D. H.; Schioppa, M.; Schlenstedt, S.; Schleper, P.; Schmidke, W. B.; Schneekloth, U.; Schönberg, V.; Schörner-Sadenius, T.; Schwartz, J.; Sciulli, F.; Shcheglova, L. M.; Shehzadi, R.; Shimizu, S.; Singh, I.; Skillicorn, I. O.; Slominski, W.; Smith, W. H.; Sola, V.; Solano, A.; Son, D.; Sosnovtsev, V.; Spiridonov, A.; Stadie, H.; Stanco, L.; Stefaniuk, N.; Stern, A.; Stewart, T. P.; Stifutkin, A.; Stopa, P.; Suchkov, S.; Susinno, G.; Suszycki, L.; Sztuk-Dambietz, J.; Szuba, D.; Szuba, J.; Tapper, A. D.; Tassi, E.; Terrón, J.; Theedt, T.; Tiecke, H.; Tokushuku, K.; Tomaszewska, J.; Trofymov, A.; Trusov, V.; Tsurugai, T.; Turcato, M.; Turkot, O.; Tymieniecka, T.; Vázquez, M.; Verbytskyi, A.; Viazlo, O.; Vlasov, N. N.; Walczak, R.; Wan Abdullah, W. A. T.; Whitmore, J. J.; Wichmann, K.; Wiggers, L.; Wing, M.; Wlasenko, M.; Wolf, G.; Wolfe, H.; Wrona, K.; Yagües-Molina, A. G.; Yamada, S.; Yamazaki, Y.; Yoshida, R.; Youngman, C.; Zakharchuk, N.; ?arnecki, A. F.; Zawiejski, L.; Zenaiev, O.; Zeuner, W.; Zhautykov, B. O.; Zhmak, N.; Zichichi, A.; Zolkapli, Z.; Zotkin, D. S.

    2013-05-01

    The production of D *± mesons in deep inelastic ep scattering has been measured for exchanged photon virtualities 5 < Q 2 < 1000 GeV2, using an integrated luminosity of 363 pb-1 with the ZEUS detector at HERA. Differential cross sections have been measured and compared to next-to-leading-order QCD calculations. The cross-sections are used to extract the charm contribution to the proton structure functions, expressed in terms of the reduced charm cross section, ?_{red}^{{coverline{c}}} . Theoretical calculations based on fits to inclusive HERA data are compared to the results.

  5. Measurement of isolated photon production in deep inelastic ep scattering

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Antonioli, P.; Bari, G.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cindolo, F.; Corradi, M.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Antonelli, S.; Basile, M.; Bindi, M.; Cifarelli, L.; Contin, A.; De Pasquale, S.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Nuncio-Quiroz, A. E.; Paul, E.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Morris, J. D.; Kaur, M.; Kaur, P.; Singh, I.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ibrahim, Z. A.; Idris, F. Mohamad; Kamaluddin, B.; Abdullah, W. A. T. Wan; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Pawlik, B.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Bachynska, O.; Behnke, O.; Behr, J.; Behrens, U.; Blohm, C.; Borras, K.; Bot, D.; Ciesielski, R.; Coppola, N.; Fang, S.; Geiser, A.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Hüttmann, A.; Januschek, F.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Libov, V.; Lisovyi, M.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Parenti, A.; Roloff, P.; Rubinsky, I.; Schneekloth, U.; Spiridonov, A.; Szuba, D.; Szuba, J.; Theedt, T.; Tomaszewska, J.; Wolf, G.; Wrona, K.; Yagües-Molina, A. G.; Youngman, C.; Zeuner, W.; Drugakov, V.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Holm, U.; Klanner, R.; Lohrmann, E.; Perrey, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Stadie, H.; Turcato, M.; Long, K. R.; Tapper, A. D.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Borodin, M.; Kadenko, I.; Korol, Ie.; Kuprash, O.; Lontkovskyi, D.; Makarenko, I.; Onishchuk, Yu.; Salii, A.; Sorokin, Iu.; Verbytskyi, A.; Viazlo, V.; Volynets, O.; Zenaiev, O.; Zolko, M.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; del Peso, J.; Ron, E.; Terrón, J.; Uribe-Estrada, C.; Corriveau, F.; Schwartz, J.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Gladkov, D.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Yu. A.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Abt, I.; Caldwell, A.; Kollar, D.; Reisert, B.; Schmidke, W. B.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Ferrando, J.; Foster, B.; Gwenlan, C.; Horton, K.; Oliver, K.; Robertson, A.; Walczak, R.; Bertolin, A.; Dal Corso, F.; Dusini, S.; Longhin, A.; Stanco, L.; Brugnera, R.; Carlin, R.; Garfagnini, A.; Limentani, S.; Oh, B. Y.; Raval, A.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Hart, J. C.; Abramowicz, H.; Ingbir, R.; Kananov, S.; Levy, A.; Stern, A.; Ishitsuka, M.; Kanno, T.; Kuze, M.; Maeda, J.; Hori, R.; Okazaki, N.; Shimizu, S.; Hamatsu, R.; Kitamura, S.; Ota, O.; Ri, Y. D.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Sola, V.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Stewart, T. P.; Boutle, S. K.; Butterworth, J. M.; Jones, T. W.; Loizides, J. H.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Perlanski, W.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Tymieniecka, T.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Brownson, E.; Reeder, D. D.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Hartner, G.; Noor, U.; Whyte, J.; ZEUS Collaboration

    2010-04-01

    Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320 pb. Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges 45 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q, x, ET? and ?. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range.

  6. Emission of reactive compounds and secondary products from wood-based furniture coatings

    NASA Astrophysics Data System (ADS)

    Salthammer, T.; Schwarz, A.; Fuhrmann, F.

    Emissions of organic fragmentation products, so-called "secondary emission products" and reactive species from wood-based furniture coatings have been studied in 1 m 3 test chambers. the climatic conditions were representative of indoor environments. Relevant compounds and compound groups were the wetting agent 2,4,7,9-tetramethyl-5-dicyne-4,7-diol (T4MDD), the plasticiser di-2-ethyl-hexyl-phthalate (DEHP), aliphatic aldehydes, monoterpenes, photoinitiator fragments, acrylic monomers/reactive solvents and diisocyanate monomers. Such substances may affect human health in several ways. Aliphatic aldehydes and some photoinitiator fragments are of strong odour, while acrylates and diisocyanates cause irritation of skin, eyes and upper airways. Terpenes and reactive solvents like styrene undergo indoor chemistry in the presence of ozone, nitrogen oxides or hydroxy radicals. Secondary emission products and reactive species can achieve significant indoor concentrations. On the other hand, it has been reported that even small quantities can cause health effects. In the cases of indoor studies with special regard to emissions from furniture, chemical analysis should always include these compounds.

  7. Complex generalized minimal residual algorithm for iterative solution of quantum-mechanical reactive scattering equations

    NASA Technical Reports Server (NTRS)

    Chatfield, David C.; Reeves, Melissa S.; Truhlar, Donald G.; Duneczky, Csilla; Schwenke, David W.

    1992-01-01

    Complex dense matrices corresponding to the D + H2 and O + HD reactions were solved using a complex generalized minimal residual (GMRes) algorithm described by Saad and Schultz (1986) and Saad (1990). To provide a test case with a different structure, the H + H2 system was also considered. It is shown that the computational effort for solutions with the GMRes algorithm depends on the dimension of the linear system, the total energy of the scattering problem, and the accuracy criterion. In several cases with dimensions in the range 1110-5632, the GMRes algorithm outperformed the LAPACK direct solver, with speedups for the linear equation solution as large as a factor of 23.

  8. Evidence of Phenotypic and Genetic Relationships between Sociality, Emotional Reactivity and Production Traits in Japanese Quail

    PubMed Central

    Recoquillay, Julien; Leterrier, Christine; Calandreau, Ludovic; Bertin, Aline; Pitel, Frédérique; Gourichon, David; Vignal, Alain; Beaumont, Catherine; Le Bihan-Duval, Elisabeth; Arnould, Cécile

    2013-01-01

    The social behavior of animals, which is partially controlled by genetics, is one of the factors involved in their adaptation to large breeding groups. To understand better the relationships between different social behaviors, fear behaviors and production traits, we analyzed the phenotypic and genetic correlations of these traits in Japanese quail by a second generation crossing of two lines divergently selected for their social reinstatement behavior. Analyses of results for 900 individuals showed that the phenotypic correlations between behavioral traits were low with the exception of significant correlations between sexual behavior and aggressive pecks both at phenotypic (0.51) and genetic (0.90) levels. Significant positive genetic correlations were observed between emotional reactivity toward a novel object and sexual (0.89) or aggressive (0.63) behaviors. The other genetic correlations were observed mainly between behavioral and production traits. Thus, the level of emotional reactivity, estimated by the duration of tonic immobility, was positively correlated with weight at 17 and 65 days of age (0.76 and 0.79, respectively) and with delayed egg laying onset (0.74). In contrast, a higher level of social reinstatement behavior was associated with an earlier egg laying onset (-0.71). In addition, a strong sexual motivation was correlated with an earlier laying onset (-0.68) and a higher number of eggs laid (0.82). A low level of emotional reactivity toward a novel object and also a higher aggressive behavior were genetically correlated with a higher number of eggs laid (0.61 and 0.58, respectively). These results bring new insights into the complex determinism of social and emotional reactivity behaviors in birds and their relationships with production traits. Furthermore, they highlight the need to combine animal welfare and production traits in selection programs by taking into account traits of sociability and emotional reactivity. PMID:24324761

  9. Zero energy resonances in reactive scattering: anomalous temperature dependence of atom--molecule reaction rates

    NASA Astrophysics Data System (ADS)

    Simbotin, I.; Ghosal, S.; Côté, R.

    2010-03-01

    We show that rate coefficients for inelastic processes---reactive, or nonreactive---in the (ultra)cold regime can be greatly affected by the presence of a resonance pole near E=0 in the entrance channel. This problem has been investigated previously [E. Bodo et al., J. Phys. B 37 (2004) 3641] but their analysis was restricted to the energy dependence of the reaction cross section for a particular case. Here, we present the general case, and we emphasize the possibility of a wide intermediate regime of temperatures where the rate coefficient has an anomalous temperature dependence; namely it increases as 1/T when T decreases. Eventually, the temperature dependence reverts back to the standard behavior given by Wigner's law, i.e., the rate coefficient becomes constant, but this may only be recovered at extremely low T (very deep into the ultracold regime). Thus, at least in some exceptional cases, most of the (ultra)cold regime could be dominated by this anomalous behavior.

  10. Towards a specific reaction parameter density functional for reactive scattering of H{sub 2} from Pd(111)

    SciTech Connect

    Boereboom, J. M.; Wijzenbroek, M.; Somers, M. F.; Kroes, G. J.

    2013-12-28

    Recently, an implementation of the specific reaction parameter (SRP) approach to density functional theory (DFT) was used to study several reactive scattering experiments of H{sub 2} on Cu(111). It was possible to obtain chemical accuracy (1 kcal/mol ? 4.2 kJ/mol), and therefore, accurately model this paradigmatic example of activated H{sub 2} dissociation on a metal surface. In this work, the SRP-DFT methodology is applied to the dissociation of hydrogen on a Pd(111) surface, in order to test whether the SRP-DFT approach is also applicable to non-activated H{sub 2}-metal systems. In the calculations, the Born–Oppenheimer static surface approximations are used. A comparison to molecular beam sticking experiments, performed at incidence energies ?125 meV, on H{sub 2} + Pd(111) suggested the PBE-vdW [where the Perdew, Burke, and Ernzerhof (PBE) correlation is replaced by van der Waals correlation] functional as a candidate SRP density functional describing the reactive scattering of H{sub 2} on Pd(111). Unfortunately, quantum dynamics calculations are not able to reproduce the molecular beam sticking results for incidence energies <125 meV. From a comparison to initial state-resolved (degeneracy averaged) sticking probabilities it seems clear that for H{sub 2} + Pd(111) dynamic trapping and steering effects are important, and that these effects are not yet well modeled with the potential energy surfaces considered here. Applying the SRP-DFT method to systems where H{sub 2} dissociation is non-activated remains difficult. It is suggested that a density functional that yields a broader barrier distribution and has more non-activated pathways than PBE-vdW (i.e., non-activated dissociation at some sites but similarly high barriers at the high energy end of the spectrum) should allow a more accurate description of the available experiments. Finally, it is suggested that new and better characterized molecular beam sticking experiments be done on H{sub 2} + Pd(111), to facilitate the development of a more accurate theoretical description of this system.

  11. Mitochondrial complex I inhibitor rotenone induces apoptosis through enhancing mitochondrial reactive oxygen species production.

    PubMed

    Li, Nianyu; Ragheb, Kathy; Lawler, Gretchen; Sturgis, Jennie; Rajwa, Bartek; Melendez, J Andres; Robinson, J Paul

    2003-03-01

    Inhibition of mitochondrial respiratory chain complex I by rotenone had been found to induce cell death in a variety of cells. However, the mechanism is still elusive. Because reactive oxygen species (ROS) play an important role in apoptosis and inhibition of mitochondrial respiratory chain complex I by rotenone was thought to be able to elevate mitochondrial ROS production, we investigated the relationship between rotenone-induced apoptosis and mitochondrial reactive oxygen species. Rotenone was able to induce mitochondrial complex I substrate-supported mitochondrial ROS production both in isolated mitochondria from HL-60 cells as well as in cultured cells. Rotenone-induced apoptosis was confirmed by DNA fragmentation, cytochrome c release, and caspase 3 activity. A quantitative correlation between rotenone-induced apoptosis and rotenone-induced mitochondrial ROS production was identified. Rotenone-induced apoptosis was inhibited by treatment with antioxidants (glutathione, N-acetylcysteine, and vitamin C). The role of rotenone-induced mitochondrial ROS in apoptosis was also confirmed by the finding that HT1080 cells overexpressing magnesium superoxide dismutase were more resistant to rotenone-induced apoptosis than control cells. These results suggest that rotenone is able to induce apoptosis via enhancing the amount of mitochondrial reactive oxygen species production. PMID:12496265

  12. Measurement of beauty production in deep inelastic scattering at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Loizides, J. H.; Magill, S.; Miglioranzi, S.; Musgrave, B.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Pavel, N.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Giusti, P.; Iacobucci, G.; Margotti, A.; Montanari, A.; Nania, R.; Palmonari, F.; Pesci, A.; Rinaldi, L.; Sartorelli, G.; Zichichi, A.; Aghuzumtsyan, G.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Kind, O.; Meyer, U.; Paul, E.; Rautenberg, J.; Renner, R.; Stifutkin, A.; Tandler, J.; Voss, K. C.; Wang, M.; Bailey, D. S.; Brook, N. H.; Cole, J. E.; Heath, G. P.; Namsoo, T.; Robins, S.; Wing, M.; Capua, M.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Kim, J. Y.; Lim, I. T.; Ma, K. J.; Pac, M. Y.; Helbich, M.; Ning, Y.; Ren, Z.; Schmidke, W. B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; Kowal, A. M.; Kowal, M.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Szuba, D.; Szuba, J.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Borras, K.; Chiochia, V.; Dannheim, D.; Drews, G.; Fourletova, J.; Fricke, U.; Geiser, A.; Göttlicher, P.; Gutsche, O.; Haas, T.; Hain, W.; Hillert, S.; Horn, C.; Kahle, B.; Kötz, U.; Kowalski, H.; Kramberger, G.; Labes, H.; Lelas, D.; Lim, H.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Nguyen, C. N.; Notz, D.; Nuncio-Quiroz, A. E.; Polini, A.; Raval, A.; Schneekloth, U.; Stösslein, U.; Wolf, G.; Youngman, C.; Zeuner, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Genta, C.; Pelfer, P. G.; Bamberger, A.; Benen, A.; Karstens, F.; Dobur, D.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Ferrando, J.; Hamilton, J.; Hanlon, S.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Carli, T.; Gosau, T.; Holm, U.; Krumnack, N.; Lohrmann, E.; Milite, M.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Stonjek, S.; Wichmann, K.; Wick, K.; Ziegler, A.; Ziegler, Ar.; Collins-Tooth, C.; Foudas, C.; Gonçalo, R.; Long, K. R.; Tapper, A. D.; Cloth, P.; Filges, D.; Kataoka, M.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; González, O.; Labarga, L.; del Peso, J.; Tassi, E.; Terrón, J.; Zambrana, M.; Barbi, M.; Corriveau, F.; Gliga, S.; Lainesse, J.; Padhi, S.; Stairs, D. G.; Walsh, R.; Tsurugai, T.; Antonov, A.; Danilov, P.; Dolgoshein, B. A.; Gladkov, D.; Sosnovtsev, V.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Katkov, I. I.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Liu, X.; Sutiak, J.; Coppola, N.; Grigorescu, G.; Grijpink, S.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Maddox, E.; Pellegrino, A.; Schagen, S.; Tiecke, H.; Vázquez, M.; Wiggers, L.; de Wolf, E.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Ling, T. Y.; Cooper-Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Grzelak, G.; Gwenlan, C.; Kohno, T.; Patel, S.; Straub, P. B.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Parenti, A.; Posocco, M.; Stanco, L.; Turcato, M.; Heaphy, E. A.; Metlica, F.; Oh, B. Y.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cormack, C.; Hart, J. C.; McCubbin, N. A.; Heusch, C.; Park, I. H.; Abramowicz, H.; Gabareen, A.; Kananov, S.; Kreisel, A.; Levy, A.; Kuze, M.; Fusayasu, T.; Kagawa, S.; Tawara, T.; Yamashita, T.; Hamatsu, R.; Hirose, T.; Inuzuka, M.; Kaji, H.; Kitamura, S.; Matsuzawa, K.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Koop, T.; Martin, J. F.; Mirea, A.; Butterworth, J. M.; Hall-Wilton, R.; Jones, T. W.; Lightwood, M. S.; Sutton, M. R.; Targett-Adams, C.; Ciborowski, J.; Ciesielski, R.; ?u?niak, P.; Nowak, R. J.; Pawlak, J. M.; Sztuk, J.; Tymieniecka, T.; Ukleja, A.; Ukleja, J.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Riveline, M.; Everett, A.; Gladilin, L. K.; Kçira, D.; Lammers, S.; Li, L.; Reeder, D. D.; Rosin, M.; Ryan, P.; Savin, A. A.; Smith, W. H.; Dhawan, S.; Bhadra, S.; Catterall, C. D.; Fourletov, S.; Hartner, G.; Menary, S.; Soares, M.; Standage, J.; ZEUS Collaboration

    2004-10-01

    The beauty production cross section for deep inelastic scattering events with at least one hard jet in the Breit frame together with a muon has been measured, for photon virtualities Q2 > 2?GeV2, with the ZEUS detector at HERA using integrated luminosity of 72 pb-1. The total visible cross section is ?bbbar (ep ? e?jet? ?X) = 40.9 ± 5.7(stat.)-4.4+6.0 (syst.)?pb. The next-to-leading order QCD prediction lies about 2.5 standard deviations below the data. The differential cross sections are in general consistent with the NLO QCD predictions; however at low values of Q2, Bjorken x, and muon transverse momentum, and high values of jet transverse energy and muon pseudorapidity, the prediction is about two standard deviations below the data.

  13. Reactivity and stability of glucosinolates and their breakdown products in foods.

    PubMed

    Hanschen, Franziska S; Lamy, Evelyn; Schreiner, Monika; Rohn, Sascha

    2014-10-20

    The chemistry of glucosinolates and their behavior during food processing is very complex. Their instability leads to the formation of a bunch of breakdown and reaction products that are very often reactive themselves. Although excessive consumption of cabbage varieties has been thought for long time to have adverse, especially goitrogenic effects, nowadays, epidemiologic studies provide data that there might be beneficial health effects as well. Especially Brassica vegetables, such as broccoli, radish, or cabbage, are rich in these interesting plant metabolites. However, information on the bioactivity of glucosinolates is only valuable when one knows which compounds are formed during processing and subsequent consumption. This review provides a comprehensive, in-depth overview on the chemical reactivity of different glucosinolates and breakdown products thereof during food preparation. PMID:25163974

  14. Energy evolution of the large-t elastic scattering and its correlation with multiparticle production

    SciTech Connect

    Troshin, S. M.

    2013-04-15

    It is emphasized that the collective dynamics associated with color confinement is dominating over a point-like mechanism related to a scattering of the proton constituents at the currently available values of the momentum transferred in proton elastic scattering at the LHC. Deep-elastic scattering and its role in the dissimilation of the absorptive and reflective asymptotic scattering mechanisms are discussed with emphasis on the experimental signatures associated with the multiparticle production processes.

  15. Impact of maternal dexamethasone on coronary PGE2 production and prostaglandin-dependent coronary reactivity

    PubMed Central

    Volk, Kenneth A.; Lamb, Fred S.; Segar, Jeffrey L.

    2012-01-01

    Intrauterine growth restriction is associated with increased fetal glucocorticoid exposure and an increased risk of adult coronary artery disease. Coronary arteries from sheep exposed to early gestation dexamethasone (Dex) have increased constriction to angiotensin II (ANG II). Prostaglandin E2 (PGE2) helps maintain coronary dilation, but PGE2 production is acutely decreased by Dex administration. We hypothesized early gestation Dex exposure impairs adult coronary PGE2 production with subsequent increases in coronary reactivity. Dex was administered to ewes at 27–28 days gestation (term 145 days). Coronary reactivity was assessed by wire myography in offspring at 4 mo of age (N = 5 to 7). Coronary smooth muscle cells were cultured and prostaglandin production was measured after 90 min incubation with radiolabeled arachidonate. Coronary myocytes from Dex-exposed lambs had a significant decrease in PGE2 production that was reversed with ANG II incubation. Dex-exposed coronary arteries had increased constriction to ANG II and attenuated dilatation to arachidonic acid, with the greatest difference seen after the endothelium was inactivated by rubbing. Preincubation with the cyclooxygenase (COX) inhibitor indomethacin altered control responses and recapitulated the heightened coronary tone seen following Dex exposure. We conclude that impaired coronary smooth muscle COX-mediated PGE2 production contributes to the coronary dysfunction elicited by early gestation Dex. Programmed inhibition of vasodilatory prostanoid production may link an adverse intrauterine environment with adult coronary artery disease. PMID:22832534

  16. Reactant coordinate based state-to-state reactive scattering dynamics implemented on graphical processing units.

    PubMed

    Zhang, Pei-Yu; Han, Ke-Li

    2014-10-01

    A parallel code for state-to-state quantum dynamics with propagation of time-dependent wavepacket in reactant coordinates has been developed on graphical processing units (GPUs). The propagation of wavepacket and the transformation of wavepacket from reactant to product Jacobi coordinates are entirely calculated on GPUs. A new interpolation procedure is introduced for coordinate transformation to decrease the five-loop computation to two four-loop computations. This procedure has a negligible consumption of extra GPU memory in comparison with that of the wavepacket and produces a considerable acceleration of the computational speed of the transformation. The code is tested to get differential cross sections of H+HD reaction and state-resolved reaction probabilities of O+HD for total angular momenta J = 0, 10, 20, and 30. The average speedups are 57.0 and 83.5 for the parallel computations on two C2070 and K20m GPUs relative to serial computation on Intel E5620 CPU, respectively. PMID:24940722

  17. S-matrix approach for pion re-scattering in {pi}0 production

    SciTech Connect

    Malafaia, V.; Pena, M.T.; Adam, J. Jr.

    2005-05-06

    The pion re-scattering operator for pion production, obtained in time-ordered perturbation theory, is used as a reference result to study retardation effects in the exchanged pion propagator and off-shell dependencies intrinsic to production models. We found that the S-matrix construction of the re-scattering operator describes these effects well.

  18. Catalytic reactive separation system for energy-efficient production of cumene

    DOEpatents

    Buelna, Genoveva (Nuevo Laredo, MX); Nenoff, Tina M. (Albuquerque, NM)

    2009-07-28

    The present invention relates to an atmospheric pressure, reactive separation column packed with a solid acid zeolite catalyst for producing cumene from the reaction of benzene with propylene. Use of this un-pressurized column, where simultaneous reaction and partial separation occur during cumene production, allow separation of un-reacted, excess benzene from other products as they form. This high-yielding, energy-efficient system allows for one-step processing of cumene, with reduced need for product purification. Reacting propylene and benzene in the presence of beta zeolite catalysts generated a selectivity greater than 85% for catalytic separation reactions at a reaction temperature of 115 degrees C and at ambient pressure. Simultaneously, up to 76% of un-reacted benzene was separated from the product; which could be recycled back to the reactor for re-use.

  19. Computational simulation of reactive species production by methane-air DBD at high pressure and high temperature

    NASA Astrophysics Data System (ADS)

    Takana, H.; Tanaka, Y.; Nishiyama, H.

    2012-01-01

    Computational simulations of a single streamer in DBD in lean methane-air mixture at pressure of 1 and 3 atm and temperature of 300 and 500 K were conducted for plasma-enhanced chemical reactions in a closed system. The effects of surrounding pressure and temperature are characterized for reactive species production by a DBD discharge. The results show that the production characteristics of reactive species are strongly influenced by the total gas number density and the higher concentration of reactive species are produced at higher pressure and lower gas temperature for a given initial reduced electric field.

  20. Scale-up of the production of highly reactive biogenic magnetite nanoparticles using Geobacter sulfurreducens

    PubMed Central

    Byrne, J. M.; Muhamadali, H.; Coker, V. S.; Cooper, J.; Lloyd, J. R.

    2015-01-01

    Although there are numerous examples of large-scale commercial microbial synthesis routes for organic bioproducts, few studies have addressed the obvious potential for microbial systems to produce inorganic functional biomaterials at scale. Here we address this by focusing on the production of nanoscale biomagnetite particles by the Fe(III)-reducing bacterium Geobacter sulfurreducens, which was scaled up successfully from laboratory- to pilot plant-scale production, while maintaining the surface reactivity and magnetic properties which make this material well suited to commercial exploitation. At the largest scale tested, the bacterium was grown in a 50 l bioreactor, harvested and then inoculated into a buffer solution containing Fe(III)-oxyhydroxide and an electron donor and mediator, which promoted the formation of magnetite in under 24 h. This procedure was capable of producing up to 120 g of biomagnetite. The particle size distribution was maintained between 10 and 15 nm during scale-up of this second step from 10 ml to 10 l, with conserved magnetic properties and surface reactivity; the latter demonstrated by the reduction of Cr(VI). The process presented provides an environmentally benign route to magnetite production and serves as an alternative to harsher synthetic techniques, with the clear potential to be used to produce kilogram to tonne quantities. PMID:25972437

  1. Analytical Expressions for the Hard-Scattering Production of Massive Partons

    E-print Network

    Cheuk-Yin Wong

    2015-10-16

    We obtain explicit expressions for the two-particle differential cross section and the two-particle angular correlation function in the hard-scattering production of massive partons in order to exhibit the ``ridge" structure on the away side in the hard-scattering process. The single-particle production cross section is also obtained and compared with the ALICE experimental data for charm production in pp collisions at 7 TeV at LHC.

  2. Mitochondrial uncoupling does not decrease reactive oxygen species production after ischemia-reperfusion

    PubMed Central

    Quarrie, Ricardo; Lee, Daniel S.; Reyes, Levy; Erdahl, Warren; Pfeiffer, Douglas R.; Zweier, Jay L.

    2014-01-01

    Cardiac ischemia-reperfusion (IR) leads to myocardial dysfunction by increasing production of reactive oxygen species (ROS). Mitochondrial H+ leak decreases ROS formation; it has been postulated that increasing H+ leak may be a mechanism of decreasing ROS production after IR. Ischemic preconditioning (IPC) decreases ROS formation after IR, but the mechanism is unknown. We hypothesize that pharmacologically increasing mitochondrial H+ leak would decrease ROS production after IR. We further hypothesize that IPC would be associated with an increase in the rate of H+ leak. Isolated male Sprague-Dawley rat hearts were subjected to either control or IPC. Mitochondria were isolated at end equilibration, end ischemia, and end reperfusion. Mitochondrial membrane potential (m??) was measured using a tetraphenylphosphonium electrode. Mitochondrial uncoupling was achieved by adding increasing concentrations of FCCP. Mitochondrial ROS production was measured by fluorometry using Amplex-Red. Pyridine dinucleotide levels were measured using HPLC. Before IR, increasing H+ leak decreased mitochondrial ROS production. After IR, ROS production was not affected by increasing H+ leak. H+ leak increased at end ischemia in control mitochondria. IPC mitochondria showed no change in the rate of H+ leak throughout IR. NADPH levels decreased after IR in both IPC and control mitochondria while NADH increased. Pharmacologically, increasing H+ leak is not a method of decreasing ROS production after IR. Replenishing the NADPH pool may be a means of scavenging the excess ROS thereby attenuating oxidative damage after IR. PMID:25085966

  3. Mitochondrial uncoupling does not decrease reactive oxygen species production after ischemia-reperfusion.

    PubMed

    Quarrie, Ricardo; Lee, Daniel S; Reyes, Levy; Erdahl, Warren; Pfeiffer, Douglas R; Zweier, Jay L; Crestanello, Juan A

    2014-10-01

    Cardiac ischemia-reperfusion (IR) leads to myocardial dysfunction by increasing production of reactive oxygen species (ROS). Mitochondrial H(+) leak decreases ROS formation; it has been postulated that increasing H(+) leak may be a mechanism of decreasing ROS production after IR. Ischemic preconditioning (IPC) decreases ROS formation after IR, but the mechanism is unknown. We hypothesize that pharmacologically increasing mitochondrial H(+) leak would decrease ROS production after IR. We further hypothesize that IPC would be associated with an increase in the rate of H(+) leak. Isolated male Sprague-Dawley rat hearts were subjected to either control or IPC. Mitochondria were isolated at end equilibration, end ischemia, and end reperfusion. Mitochondrial membrane potential (m??) was measured using a tetraphenylphosphonium electrode. Mitochondrial uncoupling was achieved by adding increasing concentrations of FCCP. Mitochondrial ROS production was measured by fluorometry using Amplex-Red. Pyridine dinucleotide levels were measured using HPLC. Before IR, increasing H(+) leak decreased mitochondrial ROS production. After IR, ROS production was not affected by increasing H(+) leak. H(+) leak increased at end ischemia in control mitochondria. IPC mitochondria showed no change in the rate of H(+) leak throughout IR. NADPH levels decreased after IR in both IPC and control mitochondria while NADH increased. Pharmacologically, increasing H(+) leak is not a method of decreasing ROS production after IR. Replenishing the NADPH pool may be a means of scavenging the excess ROS thereby attenuating oxidative damage after IR. PMID:25085966

  4. Cometary dust organics analogues: production, composition and scattered light

    NASA Astrophysics Data System (ADS)

    Hadamcik, E.; Renard, J.-B.; Carrasco, N.; Kuga, M.; Tissandier, L.; Szopa, C.

    2015-10-01

    Polarimetric observations of cometary comae may be used to infer dust particles properties through experimental simulations. Cometary organic solid materials are poorly known. Here different organic materials found in nature or synthetic are studied. Their light scattering response was correlated to their chemical composition (under heating or not). Some cometary dust analogues were obtained by mixing them with silicates and lifted in the PROGRA2 light scattering experiment.

  5. Production and characterisation of a recombinant scFv reactive with human gastrointestinal carcinomas.

    PubMed

    Kim, D-J; Chung, J-H; Ryu, Y-S; Rhim, J-H; Kim, C-W; Suh, Y; Chung, H-K

    2002-08-12

    SC142-reactive antigen are highly glycosylated glycoproteins expressed on tissues of gastric and colon cancers but not on normal tissues. Murine SC142 antibody specific for the SC142-reactive antigen has been produced by immunisation with SNU16 stomach cancer cells. However, SC142 antibody has several potential problems such as high immunogenicity and poor tumour penetration owing to their large size. To improve tumour penetration potential in vivo, recombinant single-chain fragments have been produced using the original hybridoma cells as a source of variable heavy- and variable light-chain-encoding antibody genes. The use of the polymerase chain reaction, expression cloning technology and gene expression systems in E. coli has led to the production of SC142 single-chain fragments, which was similar in activity to the SC142 parent antibody confirmed by immunohistochemistry. Analysis by DNA sequencing, SDS-PAGE and Western blotting has demonstrated the integrity of the single-chain fragments. Competitive ELISA showed that SC142 single-chain fragments originated from parent SC142 antibody. BIAcore biosensor binding experiments showed that the SC142 single-chain fragments had an ideal dissociation rate constant as a tumour imaging reagent. These results illustrate the potential application of these novel products as an immunodiagnostic and further immunotherapeutic reagent. PMID:12177777

  6. Production of charged spin-two gauge bosons in gluon-gluon scattering

    E-print Network

    Spyros Konitopoulos; George Savvidy

    2009-10-22

    We consider the production of charged spin-two gauge bosons in the gluon-gluon scattering and calculate polarized cross sections for each set of helicity orientations of initial and final particles. The angular dependence of this cross section is compared with the gluon-gluon scattering cross section in QCD .

  7. Exclusive Vector Meson Production and Deep Virtual Compton Scattering in Electron-Ion Collisions

    SciTech Connect

    Cazaroto, E. R.; Navarra, F. S.; Carvalho, F.; Kugeratski, M. S.; Goncalves, V. P.

    2010-11-12

    We calculate the nuclear cross section for coherent and incoherent deep virtual Compton scattering as well as for coherent and incoherent vector meson production for the mesons J/{Psi}, {phi} and {rho} within the QCD color dipole picture, including saturation effects. Theoretical estimates for scattering on both light and heavy nuclei are given over a wide range of energy.

  8. Mitochondrial metabolic suppression in fasting and daily torpor: consequences for reactive oxygen species production.

    PubMed

    Brown, Jason C L; Staples, James F

    2011-01-01

    Abstract Daily torpor results in an ?70% decrease in metabolic rate (MR) and a 20%-70% decrease in state 3 (phosphorylating) respiration rate of isolated liver mitochondria in both dwarf Siberian hamsters and mice even when measured at 37°C. This study investigated whether mitochondrial metabolic suppression also occurs in these species during euthermic fasting, when MR decreases significantly but torpor is not observed. State 3 respiration rate measured at 37°C was 20%-30% lower in euthermic fasted animals when glutamate but not succinate was used as a substrate. This suggests that electron transport chain complex I is inhibited during fasting. We also investigated whether mitochondrial metabolic suppression alters mitochondrial reactive oxygen species (ROS) production. In both torpor and euthermic fasting, ROS production (measured as H(2)O(2) release rate) was lower with glutamate in the presence (but not absence) of rotenone when measured at 37°C, likely reflecting inhibition at or upstream of the complex I ROS-producing site. ROS production with succinate (with rotenone) increased in torpor but not euthermic fasting, reflecting complex II inhibition during torpor only. Finally, mitochondrial ROS production was twofold more temperature sensitive than mitochondrial respiration (as reflected by Q(10) values). These data suggest that electron leak from the mitochondrial electron transport chain, which leads to ROS production, is avoided more efficiently at the lower body temperatures experienced during torpor. PMID:21897084

  9. Occurrence, pathways and implications of biological production of reactive oxygen species in natural waters

    NASA Astrophysics Data System (ADS)

    Zhang, T.; Hansel, C. M.; Voelker, B. M.; Lamborg, C. H.

    2014-12-01

    Reactive oxygen species (ROS), such as superoxide (O2-) and hydrogen peroxide (H2O2) play a critical role in the redox cycling of both toxic (e.g., Hg) and nutrient (e.g., Fe) metals. Despite the discovery of extracellular ROS production in various microbial cultures, including fungi, algae and bacteria, photo-dependent processes are generally considered as the predominant source of ROS in natural waters. Here we show that biological production of ROS is ubiquitous and occurs at a significant rate in freshwater and brackish water environments. Water samples were collected from three freshwater and one brackish water ponds in Cape Cod, Massachusetts, USA, periodically from 2012 to 2014. Production of O2- and H2O2 were measured in dark incubations of natural water using a chemiluminescent and a colorimetric probe, respectively. Rates of biological ROS production were obtained by comparing unfiltered with 0.2-?m filtered samples. The role of biological activity in ROS production was confirmed by the cessation of ROS production upon addition of formaldehyde. In surface water, production rates of O2- ranged from undetectable to 96.0 ± 30.0 nmol L-1 h-1, and production rates of H2O2 varied between 9.9 ± 1.3 nmol L-1 h-1 and 145.6 ± 11.2 nmol L-1 h-1. The maximum production rates of both ROS were observed in mid-summer 2013, which coincides with peak biological activity. ROS production in the water from aphotic zone was greater than in the water from photic zone. Thus, non-light dependent biological processes are likely the major contributors to ROS production in this system. Moreover, O2- production appeared to be enhanced by NADH and inhibited by proteinase-K, suggesting the possible involvement of NADH oxidoreductases in this process. The potential role of different microbial communities in ROS production, and the implications of biological ROS production for mercury speciation will also be discussed.

  10. The essential oil of bergamot stimulates reactive oxygen species production in human polymorphonuclear leukocytes.

    PubMed

    Cosentino, Marco; Luini, Alessandra; Bombelli, Raffaella; Corasaniti, Maria T; Bagetta, Giacinto; Marino, Franca

    2014-08-01

    Bergamot (Citrus aurantium L. subsp. bergamia) essential oil (BEO) is used in folk medicine as an antiseptic and anthelminthic and to facilitate wound healing. Evidence indicates that BEO has substantial antimicrobial activity; however its effects on immunity have never been examined. We studied the effects of BEO on reactive oxygen species (ROS) production in human polymorphonuclear leukocytes (PMN) and the role of Ca(2+) in the functional responses evoked by BEO in these cells. Results show that BEO increased intracellular ROS production in human PMN, an effect that required the contribution of extracellular (and, to a lesser extent, of intracellular) Ca(2+) . Bergamot essential oil also significantly increased ROS production induced by the chemotactic peptide N-formyl-Met-Leu-Phe and reduced the response to the protein kinase C activator phorbol myristate acetate. In conclusion, this is the first report showing the ability of BEO to increase ROS production in human PMN. This effect could both contribute to the activity of BEO in infections and in tissue healing as well as underlie an intrinsic proinflammatory potential. The relevance of these findings for the clinical uses of BEO needs careful consideration. PMID:24458921

  11. Oxygen Pathway Modeling Estimates High Reactive Oxygen Species Production above the Highest Permanent Human Habitation

    PubMed Central

    Cano, Isaac; Selivanov, Vitaly; Gomez-Cabrero, David; Tegnér, Jesper; Roca, Josep; Wagner, Peter D.; Cascante, Marta

    2014-01-01

    The production of reactive oxygen species (ROS) from the inner mitochondrial membrane is one of many fundamental processes governing the balance between health and disease. It is well known that ROS are necessary signaling molecules in gene expression, yet when expressed at high levels, ROS may cause oxidative stress and cell damage. Both hypoxia and hyperoxia may alter ROS production by changing mitochondrial Po2 (). Because depends on the balance between O2 transport and utilization, we formulated an integrative mathematical model of O2 transport and utilization in skeletal muscle to predict conditions to cause abnormally high ROS generation. Simulations using data from healthy subjects during maximal exercise at sea level reveal little mitochondrial ROS production. However, altitude triggers high mitochondrial ROS production in muscle regions with high metabolic capacity but limited O2 delivery. This altitude roughly coincides with the highest location of permanent human habitation. Above 25,000 ft., more than 90% of exercising muscle is predicted to produce abnormally high levels of ROS, corresponding to the “death zone” in mountaineering. PMID:25375931

  12. The ozone productivity of n-propyl bromide: Part 2--An exception to the Maximum Incremental Reactivity Scale.

    PubMed

    Whitten, Gary Z; Yarwood, Greg

    2008-07-01

    In an earlier paper the ozone-forming potential of n-propyl bromide (NPB) was studied with a new methodology designed to address issues associated with a marginal smog-forming compound. However, the U.S. Environmental Protection Agency (EPA) subsequently revised its policy and now recommends using the Maximum Incremental Reactivity (MIR) scale to rank the ozone-forming potential of all volatile organic compounds (VOCs), including those of marginal ozone productivity. Nevertheless, EPA contemplated exceptions to the box-model-derived MIR scale by allowing use of photochemical grid-model simulations for case specific reactivity assessments. The California Air Resources Board (CARB) also uses the MIR scale and CARB has a Reactivity Scientific Advisory Committee that can consider exceptions to the MIR scale. In this study, grid-model simulations that were recommended by EPA are used to evaluate the incremental ozone impacts of NPB using an update to the chemical mechanism developed in an earlier paper. New methods of analysis of the grid-model output are further developed here to quantify the relative reactivities between NPB and ethane over a wide range of conditions. The new grid-model-based analyses show that NPB is significantly different and generally less in ozone-forming potential (i.e., reactivity) than predicted by the box-model-based MIR scale relative to ethane, EPA's "bright-line" test for non-VOC status. Although NPB has low reactivity compared to typical VOCs on any scale, the new grid-model analyses developed here show that NPB is far less reactive (and even has negative reactivity) compared to the reactivity predicted by the MIR scale. PMID:18672713

  13. Relating multichannel scattering and production amplitudes in a microscopic OZI-based model

    SciTech Connect

    Beveren, Eef van Rupp, George

    2008-05-15

    Relations between scattering and production amplitudes are studied in a microscopic multichannel model for meson-meson scattering, with coupling to confined quark-antiquark channels. Overlapping resonances and a proper threshold behaviour are treated exactly in the model. Under the spectator assumption, it is found that the two-particle production amplitude shares a common denominator with the elastic scattering amplitude, besides a numerator consisting of a linear combination of all elastic and some inelastic matrix elements. The coefficients in these linear combinations are shown to be generally complex. Finally, the standard operator expressions relating production and scattering amplitudes, viz. A=T/VandIm(A)=T*A, are fulfilled, while in the small-coupling limit the usual isobar model is recovered.

  14. Reactive oxidation products promote secondary organic aerosol formation from green leaf volatiles

    NASA Astrophysics Data System (ADS)

    Hamilton, J. F.; Lewis, A. C.; Carey, T. J.; Wenger, J. C.; Garcia, E. Borrás. I.; Muñoz, A.

    2009-06-01

    Green leaf volatiles (GLVs) are an important group of chemicals released by vegetation which have emission fluxes that can be significantly increased when plants are damaged or stressed. A series of simulation chamber experiments has been conducted at the European Photoreactor in Valencia, Spain, to investigate secondary organic aerosol (SOA) formation from the atmospheric oxidation of the major GLVs cis-3-hexenylacetate and cis-3-hexen-1-ol. Liquid chromatography-ion trap mass spectrometry was used to identify chemical species present in the SOA. Cis-3-hexen-1-ol proved to be a more efficient SOA precursor due to the high reactivity of its first generation oxidation product, 3-hydroxypropanal, which can hydrate and undergo further reactions with other aldehydes resulting in SOA dominated by higher molecular weight oligomers. The lower SOA yields produced from cis-3-hexenylacetate are attributed to the acetate functionality, which inhibits oligomer formation in the particle phase. Based on observed SOA yields and best estimates of global emissions, these compounds may be calculated to be a substantial unidentified global source of SOA, contributing 1-5 TgC yr-1, equivalent to around a third of that predicted from isoprene. Molecular characterization of the SOA, combined with organic mechanistic information, has provided evidence that the formation of organic aerosols from GLVs is closely related to the reactivity of their first generation atmospheric oxidation products, and indicates that this may be a simple parameter that could be used in assessing the aerosol formation potential for other unstudied organic compounds in the atmosphere.

  15. Reactive oxidation products promote secondary organic aerosol formation from green leaf volatiles

    NASA Astrophysics Data System (ADS)

    Hamilton, J. F.; Lewis, A. C.; Carey, T. J.; Wenger, J. C.; Garcia, E. Borrás. I.; Muñoz, A.

    2009-02-01

    Green leaf volatiles (GLVs) are an important group of chemicals released by vegetation which have emission fluxes that can be significantly increased when plants are damaged or stressed. A series of simulation chamber experiments has been conducted at the European Photoreactor in Valencia, Spain, to investigate secondary organic aerosol (SOA) formation from the atmospheric oxidation of the major GLVs cis-3-hexenylacetate and cis-3-hexen-1-ol. Liquid chromatography-ion trap mass spectrometry was used to identify chemical species present in the SOA. Cis-3-hexen-1-ol proved to be a more efficient SOA precursor due to the high reactivity of its first generation oxidation product, 3-hydroxypropanal, which can hydrate and undergo further reactions with other aldehydes resulting in SOA dominated by higher molecular weight oligomers. The lower SOA yields produced from cis-3-hexenylacetate are attributed to the acetate functionality, which inhibits oligomer formation in the particle phase. Based on observed SOA yields and best estimates of global emissions, these compounds may be calculated to be a substantial unidentified global source of SOA, contributing 1-5 TgC yr-1, equivalent to around a third of that predicted from isoprene. Molecular characterization of the SOA, combined with organic mechanistic information, has provided evidence that the formation of organic aerosols from GLVs is closely related to the reactivity of their first generation atmospheric oxidation products, and indicates that this may be a simple parameter that could be used in assessing the aerosol formation potential for other unstudied organic compounds in the atmosphere.

  16. Interactions of U.S. Agricultural Production with Climatic Stresses and Reactive Nitrogen

    NASA Astrophysics Data System (ADS)

    Gehl, R. J.; Robertson, G. P.; Bruulsema, T. W.; Kanter, D.; Mauzerall, D. L.; Rotz, C. A.; Williams, C. O.

    2011-12-01

    Agricultural production both contributes to and responds to climatic variations across spatial and temporal continuums. The agriculture sector is responsible for over 6% of total U.S. greenhouse gas emissions, primarily as methane (CH4) and nitrous oxide (N2O) gases emitted by agricultural activities. Agriculture activities specifically account for about 69% of U.S. N2O emissions, largely as a result of production practices including fertilizer management, cropping systems, and manure management. Fertilizers, together with manure and legume fixation, are the three main inputs of N to US agricultural soils. All three sources have been increasing over the past two decades, while the rate at which they are removed in the form of harvested crops has been increasing at a slightly slower rate. The outlook for continued large areas of cultivation in the U.S., specifically for corn production and supported by biofuel production goals, is a major factor in sustaining demand for N fertilizer. However, rising fertilizer prices and environmental pressures on producers are encouraging increased adoption of emerging technologies such as precision agriculture, cultivars with higher N use efficiency, and enhanced-efficiency N sources such as controlled-release forms or forms with urease or nitrification inhibitors. Crop productivity also responds to climatic changes, as crop growth is affected by variables including heat, drought, ozone (O3), and increased ambient carbon dioxide (CO2). We summarize sources and fates of N for cropping systems and intensive animal systems and assess how climate change will affect crop response to and recovery of N and subsequent cascading effects on Nr. The complex interactions between agricultural Nr and climate present opportunities for mitigation/adaption relative to N use. N fertilizer and manure management, tillage, technology, and decision support models provide significant opportunities for climate mitigation and adaption in U.S. agriculture. Here we summarize reactive nitrogen (Nr)-climate interactions as they relate to U.S. agricultural production.

  17. Mechanisms of photochemistry and reactive oxygen production by fullerene suspensions in water.

    PubMed

    Hotze, Ernest M; Labille, Jerome; Alvarez, Pedro; Wiesner, Mark R

    2008-06-01

    Buckminsterfullerene (C60) is a known photosensitizer that produces reactive oxygen species (ROS) in the presence of light; however, its properties in aqueous environments are still not well understood or modeled. In this study, production of both singlet oxygen and superoxide by UV photosensitization of colloidal aggregates of C60 in water was measured by two distinct methods: electron paramagnetic resonance (EPR) with a spin trapping compound, and spectrophotometric detection of the reduced form of the tetrazolium compound XTT. Both singlet oxygen and superoxide were generated by fullerol suspensions while neither was detected in the aqu/nC60 suspensions. A mechanistic framework for photosensitization that takes into account differences in C60 aggregate structure in water is proposed to explain these results. While theory developed for single molecules suggests that alterations to the C60 cage should reduce the quantum yield for the triplet state and associated ROS production, the failure to detect ROS production by aqu/nC60 is explained in part by a more dense aggregate structure compared with the hydroxylated C60. PMID:18589984

  18. Reactive transport modelling of the interaction of fission product ground contamination with alkaline and cementitious leachates

    SciTech Connect

    Kwong, S.; Small, J.

    2007-07-01

    The fission products Cs-137 and Sr-90 are amongst the most common radionuclides occurring in ground contamination at the UK civil nuclear sites. Such contamination is often associated with alkaline liquids and the mobility of these fission products may be affected by these chemical conditions. Similar geochemical effects may also result from cementitious leachate associated with building foundations and the use of grouts to remediate ground contamination. The behaviour of fission products in these scenarios is a complex interaction of hydrogeological and geochemical processes. A suite of modelling tools have been developed to investigate the behaviour of a radioactive plume containing Cs and Sr. Firstly the effects of sorption due to cementitious groundwater is modelled using PHREEQC. This chemical model is then incorporated into PHAST for the 3-D reactive solute transport modeling. Results are presented for a generic scenario including features and processes that are likely to be relevant to a number of civil UK nuclear sites. Initial results show that modelling can be a very cost-effective means to study the complex hydrogeological and geochemical processes involved. Modelling can help predict the mobility of contaminants in a range of site end point scenarios, and in assessing the consequences of decommissioning activities. (authors)

  19. Nicorandil prevents sirolimus-induced production of reactive oxygen species, endothelial dysfunction, and thrombus formation.

    PubMed

    Aizawa, Ken; Takahari, Youko; Higashijima, Naoko; Serizawa, Kenichi; Yogo, Kenji; Ishizuka, Nobuhiko; Endo, Koichi; Fukuyama, Naoto; Hirano, Katsuya; Ishida, Hideyuki

    2015-03-01

    Sirolimus (SRL) is widely used to prevent restenosis after percutaneous coronary intervention. However, its beneficial effect is hampered by complications of thrombosis. Several studies imply that reactive oxygen species (ROS) play a critical role in endothelial dysfunction and thrombus formation. The present study investigated the protective effect of nicorandil (NIC), an anti-angina agent, on SRL-associated thrombosis. In human coronary artery endothelial cells (HCAECs), SRL stimulated ROS production, which was prevented by co-treatment with NIC. The preventive effect of NIC on ROS was abolished by 5-hydroxydecanoate but not by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one. NIC also inhibited SRL-induced up-regulation of NADPH oxidase subunit p22(phox) mRNA. Co-treatment with NIC and SRL significantly up-regulated superoxide dismutase 2. NIC treatment significantly improved SRL-induced decrease in viability of HCAECs. The functional relevance of the preventive effects of NIC on SRL-induced ROS production and impairment of endothelial viability was investigated in a mouse model of thrombosis. Pretreatment with NIC inhibited the SRL-induced acceleration of FeCl3-initiated thrombus formation and ROS production in the testicular arteries of mice. In conclusion, NIC prevented SRL-induced thrombus formation, presumably due to the reduction of ROS and to endothelial protection. The therapeutic efficacy of NIC could represent an additional option in the prevention of SRL-related thrombosis. PMID:25837924

  20. Positronium Production and Scattering below Its Breakup Threshold

    NASA Astrophysics Data System (ADS)

    Brawley, S. J.; Fayer, S. E.; Shipman, M.; Laricchia, G.

    2015-11-01

    Recent findings on the similarity between electron and positronium scattering at the same velocity [Brawley et al., Science 330, 789 (2010)] have guided us towards the realization of a detectable flux of positronium atoms at beam energies five times lower than previously obtained, enabling total cross sections to be measured in the energy range ˜(1 - 7 ) eV for the first time. In collision with Ar and Xe, the total cross sections of positronium are found to be smallest at the lowest energy probed, approaching those of the Ramsauer-Townsend minima for electron projectiles. Additional structure has been observed in the case of positronium scattering at incident energies around 5 eV.

  1. Reactive scattering of H2 from Cu(100): Comparison of dynamics calculations based on the specific reaction parameter approach to density functional theory with experiment

    NASA Astrophysics Data System (ADS)

    Sementa, L.; Wijzenbroek, M.; van Kolck, B. J.; Somers, M. F.; Al-Halabi, A.; Busnengo, H. F.; Olsen, R. A.; Kroes, G. J.; Rutkowski, M.; Thewes, C.; Kleimeier, N. F.; Zacharias, H.

    2013-01-01

    We present new experimental and theoretical results for reactive scattering of dihydrogen from Cu(100). In the new experiments, the associative desorption of H2 is studied in a velocity resolved and final rovibrational state selected manner, using time-of-flight techniques in combination with resonance-enhanced multi-photon ionization laser detection. Average desorption energies and rotational quadrupole alignment parameters were obtained in this way for a number of (v = 0, 1) rotational states, v being the vibrational quantum number. Results of quantum dynamics calculations based on a potential energy surface computed with a specific reaction parameter (SRP) density functional, which was derived earlier for dihydrogen interacting with Cu(111), are compared with the results of the new experiments and with the results of previous molecular beam experiments on sticking of H2 and on rovibrationally elastic and inelastic scattering of H2 and D2 from Cu(100). The calculations use the Born-Oppenheimer and static surface approximations. With the functional derived semi-empirically for dihydrogen + Cu(111), a chemically accurate description is obtained of the molecular beam experiments on sticking of H2 on Cu(100), and a highly accurate description is obtained of rovibrationally elastic and inelastic scattering of D2 from Cu(100) and of the orientational dependence of the reaction of (v = 1, j = 2 - 4) H2 on Cu(100). This suggests that a SRP density functional derived for H2 interacting with a specific low index face of a metal will yield accurate results for H2 reactively scattering from another low index face of the same metal, and that it may also yield accurate results for H2 interacting with a defected (e.g., stepped) surface of that same metal, in a system of catalytic interest. However, the description that was obtained of the average desorption energies, of rovibrationally elastic and inelastic scattering of H2 from Cu(100), and of the orientational dependence of reaction of (v = 0, j = 3 - 5, 8) H2 on Cu(100) compares less well with the available experiments. More research is needed to establish whether more accurate SRP-density functional theory dynamics results can be obtained for these observables if surface atom motion is added to the dynamical model. The experimentally and theoretically found dependence of the rotational quadrupole alignment parameter on the rotational quantum number provides evidence for rotational enhancement of reaction at low translational energies.

  2. Nuclear A dependence of exclusive vector meson production in muon scattering

    SciTech Connect

    Schellman, H.; E665 Collaboration

    1994-07-01

    Results on exclusive vector meson production from Fermilab muon scattering experiment E665 are presented. The {Alpha} dependence of exclusive vector meson production is studied as a function of Q{sup 2}. The data show a significant change in the dependence on {Alpha} at higher values of Q{sup 2}. The observed behavior is consistent with the idea of color transparency.

  3. Reactive oxygen species and IRF1 stimulate IFN? production by proximal tubules during ischemic AKI

    PubMed Central

    Winterberg, Pamela D.; Wang, Yanxia; Lin, Keng-Mean; Hartono, John R.; Nagami, Glenn T.; Zhou, Xin J.; Shelton, John M.; Richardson, James A.

    2013-01-01

    We previously reported that expression of the transcription factor interferon regulatory factor 1 (IRF1) is an early, critical maladaptive signal expressed by renal tubules during murine ischemic acute kidney injury (AKI). We now show that IRF1 mediates signals from reactive oxygen species (ROS) generated during ischemic AKI and that these signals ultimately result in production of ?-subtypes of type I interferons (IFN?s). We found that genetic knockout of the common type I IFN receptor (IFNARI?/?) improved kidney function and histology during AKI. There are major differences in the spatial-temporal production of the two major IFN subtypes, IFN? and IFN?s: IFN? expression peaks at 4 h, earlier than IFN?s, and continues at the same level at 24 h; expression of IFN?s also increases at 4 h but continues to increase through 24 h. The magnitude of the increase in IFN?s relative to baseline is much greater than that of IFN?. We show by immunohistology and study of isolated cells that IFN? is produced by renal leukocytes and IFN?s are produced by renal tubules. IRF1, IFN?s, and IFNARI were found on the same renal tubules during ischemic AKI. Furthermore, we found that ROS induced IFN? expression by renal tubules in vitro. This expression was inhibited by small interfering RNA knockdown of IRF1. Overexpression of IRF1 resulted in the production of IFN?s. Furthermore, we found that IFN? stimulated production of maladaptive proinflammatory CXCL2 by renal tubular cells. Altogether our data support the following autocrine pathway in renal tubular cells: ROS > IRF1 > IFN? > IFNARI > CXCL2. PMID:23657854

  4. Analysis of acidity production during enhanced reductive dechlorination using a simplified reactive transport model

    NASA Astrophysics Data System (ADS)

    Brovelli, A.; Barry, D. A.; Robinson, C.; Gerhard, J. I.

    2012-07-01

    Build-up of fermentation products and hydrochloric acid at a contaminated site undergoing enhanced reductive dechlorination can result in groundwater acidification. Sub-optimal pH conditions can inhibit microbial activity and lead to reduced dechlorination rates. The extent of acidification likely to occur is site-specific and depends primarily on the extent of fermentation and dechlorination, the geochemical composition of soil and groundwater, and the pH-sensitivity of the active microbial populations. Here, the key chemical and physical mechanisms that control the extent of groundwater acidification in a contaminated site were examined, and the extent to which the remediation efficiency was affected by variations in groundwater pH was evaluated using a simplified process-based reactive-transport model. This model was applied successfully to a well-documented field site and was then employed in a sensitivity analysis to identify the processes likely to significantly influence acidity production and subsequent microbial inhibition. The accumulation of organic acids produced from the fermentation of the injected substrate was the main cause of the pH change. The concentration of dissolved sulphates controlled substrate utilisation efficiency because sulphate-reducing biomass competed with halo-respiring biomass for the fermentation products. It was shown further that increased groundwater velocity increases dilution and reduces the accumulation of acidic products. As a consequence, the flow rate corresponding to the highest remediation efficiency depends on the fermentation and dechlorination rates. The model enables investigation and forecasting of the extent and areal distribution of pH change, providing a means to optimise the application of reductive dechlorination for site remediation.

  5. Differential production of reactive oxygen species in distinct brain regions of hypoglycemic mice.

    PubMed

    Amador-Alvarado, Leticia; Montiel, Teresa; Massieu, Lourdes

    2014-09-01

    Hypoglycemia is a serious complication of insulin therapy in patients suffering from type 1 Diabetes Mellitus. Severe hypoglycemia leading to coma (isoelectricity) induces massive neuronal death in vulnerable brain regions such as the hippocampus, the striatum and the cerebral cortex. It has been suggested that the production of reactive oxygen species (ROS) and oxidative stress is involved in hypoglycemic brain damage, and that ROS generation is stimulated by glucose reintroduction (GR) after the hypoglycemic coma. However, the distribution of ROS in discrete brain regions has not been studied in detail. Using the oxidation sensitive marker dihydroethidium (DHE) we have investigated the distribution of ROS in different regions of the mouse brain during prolonged severe hypoglycemia without isoelectricity, as well as the effect of GR on ROS levels. Results show that ROS generation increases in the hippocampus, the cerebral cortex and the striatum after prolonged severe hypoglycemia before the coma. The hippocampus showed the largest increases in ROS levels. GR further stimulated ROS production in the hippocampus and the striatum while in the cerebral cortex, only the somatosensory and parietal areas were significantly affected by GR. Results suggest that ROS are differentially produced during the hypoglycemic insult and that a different response to GR is present among distinct brain regions. PMID:24590689

  6. Urea degradation by electrochemically generated reactive chlorine species: products and reaction pathways.

    PubMed

    Cho, Kangwoo; Hoffmann, Michael R

    2014-10-01

    This study investigated the transformation of urea by electrochemically generated reactive chlorine species (RCS). Solutions of urea with chloride ions were electrolyzed using a bismuth doped TiO2 (BiOx/TiO2) anode coupled with a stainless steel cathode at applied anodic potentials (Ea) of either +2.2 V or +3.0 V versus the normal hydrogen electrode. In NaCl solution, the current efficiency of RCS generation was near 30% at both potentials. In divided cell experiments, the pseudo-first-order rate of total nitrogen decay was an order of magnitude higher at Ea of +3.0 V than at +2.2 V, presumably because dichlorine radical (Cl2(-)·) ions facilitate the urea transformation primary driven by free chlorine. Quadrupole mass spectrometer analysis of the reactor headspace revealed that N2 and CO2 are the primary gaseous products of the oxidation of urea, whose urea-N was completely transformed into N2 (91%) and NO3(-) (9%). The higher reaction selectivity with respect to N2 production can be ascribed to a low operational ratio of free available chlorine to N. The mass-balance analysis recovered urea-C as CO2 at 77%, while CO generation most likely accounts for the residual carbon. In light of these results, we propose a reaction mechanism involving chloramines and chloramides as reaction intermediates, where the initial chlorination is the rate-determining step in the overall sequence of reactions. PMID:25219459

  7. [FEATURES OF CHANGES IN THE IMMUNE REACTIVITY IN EMPLOYEES IN MODERN PRODUCTION OF SULPHATE CELLULOSE].

    PubMed

    Meshchakova, N M; Bodienkova, G M

    2015-01-01

    There are reported changes in the indices of the immunoreactivity of the body in employees in modern productions of sulphate cellulose in dependence on the specificity of exposing factors of the production environment. At that the main adverse factor affecting the state of the immune reactivity of workers was found to be is air pollution of the working area with methyl-sulfur compounds in the pulping process, with chlorine and chlorine dioxide--in the process of bleaching, lime and limestone dust--in the process of caustic regeneration. There were shown differences in the character and severity of the immune response to the impact of different chemical compounds. The exertion of protective immune mechanisms is most pronounced in workers employed in the process of boiling and bleaching, in whom there were revealed significant changes in humoral compartment of immunity (pronounced inhibition of the IgA synthesis, which plays an important role in the state of broncho-pulmonary immunity). At the same time, the inhibition of the functional activity of phagocytic neutrophils was the most significant in workers who was experienced to the exposure to lime and limestone dust, testifying about the depression of nonspecific mechanisms of anti-infectious protection. The revealed changes in the immune system are the basis for the formation in workers certain health disorders, mainly with broncho-pulmonary pathology. PMID:26625622

  8. Nuclear elastic scattering effects on fusion product transport in compact tori

    SciTech Connect

    DeVeaux, J.; Greenspan, E.; Miley, G.H.

    1980-01-01

    This paper seeks to advance previous work including the effects of nuclear elastic scattering (NES) on fusion-product transport. We have found that NES may dominate the slowing-down process for high-temperature, advance-fuel plasmas which burn Cat.D or D-/sup 3/He. A modified version of the Monte Carlo fusion product transport code, MCFRM, was used to evaluate the effects of NES on discrete fusion-product orbits in the FRM.

  9. Quantum reactive scattering of O({sup 3}P)+H{sub 2} at collision energies up to 4.4 eV

    SciTech Connect

    Gacesa, Marko; Kharchenko, Vasili

    2014-10-28

    We report the results of quantum scattering calculations for the O({sup 3}P)+H{sub 2} reaction for a range of collision energies from 0.4 to 4.4 eV, important for astrophysical and atmospheric processes. The total and state-to-state reactive cross sections are calculated using a fully quantum time-independent coupled-channel approach on recent potential energy surfaces of {sup 3}A{sup ?} and {sup 3}A{sup ?} symmetry. A larger basis set than in the previous studies was used to ensure single-surface convergence at higher energies. Our results agree well with the published data at lower energies and indicate the breakdown of reduced dimensionality approach at collision energies higher than 1.5 eV. Differential cross sections and momentum transfer cross sections are also reported.

  10. Production and immunological analysis of IgE reactive recombinant egg white allergens expressed in Escherichia coli.

    PubMed

    Dhanapala, Pathum; Doran, Tim; Tang, Mimi L K; Suphioglu, Cenk

    2015-05-01

    IgE-mediated allergy to chicken egg affects a large number of children and adults worldwide. The current management strategy for egg allergy is strict avoidance, however this is impractical due to the presence of eggs in a range of foods and pharmaceutical products including vaccines. Strict avoidance also poses nutritional disadvantages due to high nutritional value of eggs. Allergen specific immunotherapy is being pursued as a curative treatment, in which an allergic individual is gradually exposed to the allergen to induce tolerance. Use of recombinant proteins for immunotherapy has been beneficial due to the purity of the recombinant proteins compared to natural proteins. In this study, we produced IgE reactive recombinant egg white proteins that can be used for future immunotherapy. Using E. coli as an expression system, we successfully produced recombinant versions of Gal d 1, 2 and 3, that were IgE reactive when tested against a pool of egg allergic patients' sera. The IgE reactivity indicates that these recombinant proteins are capable of eliciting an immune response, thus being potential candidates for immunotherapy. We have, for the first time, attempted to produce recombinant versions of all 4 major egg white allergens in E. coli, and successfully produced 3, with only Gal d 4 showing loss of IgE reactivity in the recombinant version. The results suggest that egg allergy in Australian populations may mainly be due to IgE reactivity to Gal d 3 and 4, while Gal d 1 shows higher IgE reactivity. This is the first report of a collective and comparative immunological analysis of all 4 egg white allergens. The significance of this study is the potential use of the IgE reactive recombinant egg white proteins in immunotherapy to treat egg allergic patients. PMID:25656803

  11. Effects of Pectic Polysaccharides Isolated from Leek on the Production of Reactive Oxygen and Nitrogen Species by Phagocytes

    PubMed Central

    Nikolova, Mariana; Ambrozova, Gabriela; Kratchanova, Maria; Denev, Petko; Kussovski, Veselin; Ciz, Milan

    2013-01-01

    Abstract The current survey investigates the effect of four polysaccharides isolated from fresh leek or alcohol insoluble substances (AIS) of leek on the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) from phagocytes. The ability of the polysaccharides to activate serum complement was also investigated. Despite the lack of antioxidant activity, the pectic polysaccharides significantly decreased the production of ROS by human neutrophils. Polysaccharides isolated from AIS markedly activated RAW 264.7 macrophages for RNS production in a concentration-dependent manner. The Western blot analysis revealed that this effect was due to the stimulation of the inducible nitric oxide synthase protein expression of macrophages. The polysaccharides extracted from AIS with water showed the ability to fix serum complement, especially through the alternative pathway. It was found that the polysaccharide that has the highest complement-fixing effect is characterized by the highest content of uronic acids and the highest molecular weight. PMID:23905651

  12. Autophagy proteins control goblet cell function by potentiating reactive oxygen species production

    PubMed Central

    Patel, Khushbu K; Miyoshi, Hiroyuki; Beatty, Wandy L; Head, Richard D; Malvin, Nicole P; Cadwell, Ken; Guan, Jun-Lin; Saitoh, Tatsuya; Akira, Shizuo; Seglen, Per O; Dinauer, Mary C; Virgin, Herbert W; Stappenbeck, Thaddeus S

    2013-01-01

    Delivery of granule contents to epithelial surfaces by secretory cells is a critical physiologic process. In the intestine, goblet cells secrete mucus that is required for homeostasis. Autophagy proteins are required for secretion in some cases, though the mechanism and cell biological basis for this requirement remain unknown. We found that in colonic goblet cells, proteins involved in initiation and elongation of autophagosomes were required for efficient mucus secretion. The autophagy protein LC3 localized to intracellular multi-vesicular vacuoles that were consistent with a fusion of autophagosomes and endosomes. Using cultured intestinal epithelial cells, we found that NADPH oxidases localized to and enhanced the formation of these LC3-positive vacuoles. Both autophagy proteins and endosome formation were required for maximal production of reactive oxygen species (ROS) derived from NADPH oxidases. Importantly, generation of ROS was critical to control mucin granule accumulation in colonic goblet cells. Thus, autophagy proteins can control secretory function through ROS, which is in part generated by LC3-positive vacuole-associated NADPH oxidases. These findings provide a novel mechanism by which autophagy proteins can control secretion. PMID:24185898

  13. Silver nanoparticles affect glucose metabolism in hepatoma cells through production of reactive oxygen species

    PubMed Central

    Lee, Mi Jin; Lee, Seung Jun; Yun, Su Jin; Jang, Ji-Young; Kang, Hangoo; Kim, Kyongmin; Choi, In-Hong; Park, Sun

    2016-01-01

    The silver nanoparticle (AgNP) is a candidate for anticancer therapy because of its effects on cell survival and signaling. Although numerous reports are available regarding their effect on cell death, the effect of AgNPs on metabolism is not well understood. In this study, we investigated the effect of AgNPs on glucose metabolism in hepatoma cell lines. Lactate release from both HepG2 and Huh7 cells was reduced with 5 nm AgNPs as early as 1 hour after treatment, when cell death did not occur. Treatment with 5 nm AgNPs decreased glucose consumption in HepG2 cells but not in Huh7 cells. Treatment with 5 nm AgNPs reduced nuclear factor erythroid 2-like 2 expression in both cell types without affecting its activation at the early time points after AgNPs’ treatment. Increased reactive oxygen species (ROS) production was detected 1 hour after 5 nm AgNPs’ treatment, and lactate release was restored in the presence of an ROS scavenger. Our results suggest that 5 nm AgNPs affect glucose metabolism by producing ROS.

  14. Compton Scattering from the Deuteron below Pion-Production Threshold

    E-print Network

    Luke Myers; John Annand; Jason Brudvik; Gerald Feldman; Kevin Fissum; Harald Grießhammer; Kurt Hansen; Seth Henshaw; Lennart Isaksson; Ramsey Jebali; Michael Kovash; Magnus Lundin; Duncan Middleton; Alan Nathan; Bent Schröder; Sean Stave

    2015-03-27

    Differential cross sections for elastic scattering of photons from the deuteron have recently been measured at the Tagged-Photon Facility at the MAX IV Laboratory in Lund, Sweden. These first new measurements in more than a decade further constrain the isoscalar electromagnetic polarizabilities of the nucleon and provide the first-ever results above 100 MeV, where the sensitivity to the polarizabilities is increased. We add 23 points between 70 and 112 MeV, at angles 60deg, 120deg and 150deg. Analysis of these data using a Chiral Effective Field Theory indicates that the cross sections are both self-consistent and consistent with previous measurements. Extracted values of \\alpha_s = [12.1 +/- 0.8(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 and \\beta_s = [2.4 +/- 0.8(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 are obtained from a fit to these 23 new data points. This paper presents in detail the experimental conditions and the data analysis used to extract the cross sections.

  15. Reactive oxygen species production and redox state in parthenogenetic and sperm-mediated bovine oocyte activation.

    PubMed

    Morado, S; Cetica, P; Beconi, M; Thompson, J G; Dalvit, G

    2013-05-01

    The knowledge concerning redox and reactive oxygen species (ROS)-mediated regulation of early embryo development is scarce and remains controversial. The aim of this work was to determine ROS production and redox state during early in vitro embryo development in sperm-mediated and parthenogenetic activation of bovine oocytes. Sperm-mediated oocyte activation was carried out in IVF-modified synthetic oviductal fluid (mSOF) with frozen-thawed semen. Parthenogenetic activation was performed in TALP plus ionomycin and then in IVF-mSOF with 6-dimethylaminopurine plus cytochalasin B. Embryos were cultured in IVF-mSOF. ROS and redox state were determined at each 2-h interval (7-24?h from activation) by 2',7'-dichlorodihydrofluorescein diacetate and RedoxSensor Red CC-1 fluorochromes respectively. ROS levels and redox state differed between activated and non-activated oocytes (P<0.05 by ANOVA). In sperm-activated oocytes, an increase was observed between 15 and 19?h (P<0.05). Conversely, in parthenogenetically activated oocytes, we observed a decrease at 9?h (P<0.05). In sperm-activated oocytes, ROS fluctuated throughout the 24?h, presenting peaks around 7, 19, and 24?h (P<0.05), while in parthenogenetic activation, peaks were detected at 7, 11, and 17?h (P<0.05). In the present work, we found clear distinctive metabolic patterns between normal and parthenogenetic zygotes. Oxidative activity and ROS production are an integral part of bovine zygote behavior, and defining a temporal pattern of change may be linked with developmental competence. PMID:23630331

  16. Regulation of soybean seed germination through ethylene production in response to reactive oxygen species

    PubMed Central

    Ishibashi, Yushi; Koda, Yuka; Zheng, Shao-Hui; Yuasa, Takashi; Iwaya-Inoue, Mari

    2013-01-01

    Background and Aims Despite their toxicity, reactive oxygen species (ROS) play important roles in plant cell signalling pathways, such as mediating responses to stress or infection and in programmed cell death, at lower levels. Although studies have indicated that hydrogen peroxide (H2O2) promotes seed germination of several plants such as Arabidopsis, barley, wheat, rice and sunflower, the role of H2O2 in soybean seed germination is not well known. The aim of this study therefore was to investigate the relationships between ROS, plant hormones and soybean seed germination. Methods An examination was made of soybean seed germination, the expression of genes related to ethylene biosynthesis, endogenous ethylene contents, and the number and area of cells in the root tip, using N-acetylcysteine, an antioxidant, to counteract the effect of ROS. Key Results H2O2 promoted germination, which N-acetylcysteine suppressed, suggesting that ROS are involved in the regulation of soybean germination. H2O2 was produced in the embryonic axis after imbibition. N-Acetylcysteine suppressed the expression of genes related to ethylene biosynthesis and the production of endogenous ethylene. Interestingly, ethephon, which is converted to ethylene, and H2O2 reversed the suppression of seed germination by N-acetylcysteine. Furthermore, morphological analysis revealed that N-acetylcysteine suppressed cell elongation at the root tip, and this suppression was also reversed by ethephon or H2O2 treatments, as was the case in germination. Conclusions In soybean seeds, ROS produced in the embryonic axis after imbibition induce the production of endogenous ethylene, which promotes cell elongation in the root tip. This appears to be how ROS regulate soybean seed germination. PMID:23131300

  17. Non-thermal plasma induces apoptosis in melanoma cells via production of intracellular reactive oxygen species.

    PubMed

    Sensenig, Rachel; Kalghatgi, Sameer; Cerchar, Ekaterina; Fridman, Gregory; Shereshevsky, Alexey; Torabi, Behzad; Arjunan, Krishna Priya; Podolsky, Erica; Fridman, Alexander; Friedman, Gary; Azizkhan-Clifford, Jane; Brooks, Ari D

    2011-02-01

    Non-thermal atmospheric pressure dielectric barrier discharge (DBD) plasma may provide a novel approach to treat malignancies via induction of apoptosis. The purpose of this study was to evaluate the potential of DBD plasma to induce apoptosis in melanoma cells. Melanoma cells were exposed to plasma at doses that did not induce necrosis, and cell viability and apoptotic activity were evaluated by Trypan blue exclusion test, Annexin-V/PI staining, caspase-3 cleavage, and TUNEL® analysis. Trypan blue staining revealed that non-thermal plasma treatment significantly decreased the viability of cells in a dose-dependent manner 3 and 24 h after plasma treatment. Annexin-V/PI staining revealed a significant increase in apoptosis in plasma-treated cells at 24, 48, and 72 h post-treatment (p < 0.001). Caspase-3 cleavage was observed 48 h post-plasma treatment at a dose of 15 J/cm(2). TUNEL® analysis of plasma-treated cells demonstrated an increase in apoptosis at 48 and 72 h post-treatment (p < 0.001) at a dose of 15 J/cm(2). Pre-treatment with N-acetyl-L: -cysteine (NAC), an intracellular reactive oxygen species (ROS) scavenger, significantly decreased apoptosis in plasma-treated cells at 5 and 15 J/cm(2). Plasma treatment induces apoptosis in melanoma cells through a pathway that appears to be dependent on production of intracellular ROS. DBD plasma production of intracellular ROS leads to dose-dependent DNA damage in melanoma cells, detected by ?-H2AX, which was completely abrogated by pre-treating cells with ROS scavenger, NAC. Plasma-induced DNA damage in turn may lead to the observed plasma-induced apoptosis. Since plasma is non-thermal, it may be used to selectively treat malignancies. PMID:21046465

  18. Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging.

    PubMed

    Lee, Sang-Hyun; Jang, Hae-Dong

    2015-02-15

    Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-?B ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos-nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen species (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)-cSrc-phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression. PMID:25576385

  19. HIV antiretroviral drug combination induces endothelial mitochondrial dysfunction and reactive oxygen species production, but not apoptosis

    SciTech Connect

    Jiang Bo; Hebert, Valeria Y.; Li, Yuchi; Mathis, J. Michael; Alexander, J. Steven; Dugas, Tammy R.

    2007-10-01

    Numerous reports now indicate that HIV patients administered long-term antiretroviral therapy (ART) are at a greater risk for developing cardiovascular diseases. Endothelial dysfunction is an initiating event in atherogenesis and may contribute to HIV-associated atherosclerosis. We previously reported that ART induces direct endothelial dysfunction in rodents. In vitro treatment of human umbilical vein endothelial cells (HUVEC) with ART indicated endothelial mitochondrial dysfunction and a significant increase in the production of reactive oxygen species (ROS). In this study, we determined whether ART-induced endothelial dysfunction is mediated via mitochondria-derived ROS and whether this mitochondrial injury culminates in endothelial cell apoptosis. Two major components of ART combination therapy, a nucleoside reverse transcriptase inhibitor and a protease inhibitor, were tested, using AZT and indinavir as representatives for each. Microscopy utilizing fluorescent indicators of ROS and mitochondria demonstrated the mitochondrial localization of ART-induced ROS. MnTBAP, a cell-permeable metalloporphyrin antioxidant, abolished ART-induced ROS production. As a final step in confirming the mitochondrial origin of the ART-induced ROS, HUVEC were transduced with a cytosolic- compared to a mitochondria-targeted catalase. Transduction with the mitochondria-targeted catalase was more effective than cytoplasmic catalase in inhibiting the ROS and 8-isoprostane (8-iso-PGF{sub 2{alpha}}) produced after treatment with either AZT or indinavir. However, both mitochondrial and cytoplasmic catalase attenuated ROS and 8-iso-PGF{sub 2{alpha}} production induced by the combination treatment, suggesting that in this case, the formation of cytoplasmic ROS may also occur, and thus, that the mechanism of toxicity in the combination treatment group may be different compared to treatment with AZT or indinavir alone. Finally, to determine whether ART-induced mitochondrial dysfunction and ROS production culminate in apoptosis, we performed the terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL), annexin V and 4',6-diamidino-2-phenylindole (DAPI) staining, and caspase-3 activity assays. However, none of these assays showed appreciable levels of ART-induced apoptosis. Our studies thus suggest that in endothelial cells, ART induces mitochondrial dysfunction with a concomitant increase in mitochondria-derived ROS. This compromised mitochondrial function may be one important factor culminating in endothelial dysfunction, without inducing an increase in apoptosis.

  20. Coherent pion production by neutrino scattering off nuclei

    SciTech Connect

    Kartavtsev, A.; Paschos, E. A.; Gounaris, G. J.

    2006-09-01

    The main part of coherent pion production by neutrinos on nuclei is essentially determined by partial conservation of the axial current (PCAC), provided that the leptonic momentum transferred square Q{sup 2} remains sufficiently small. We give the formulas for the charged and neutral current cross sections, including also the small non-PCAC transverse current contributions and taking into account the effect of the {mu}{sup -}-mass. Our results are compared with the experimental ones and other theoretical treatments.

  1. Two-fireball model for hadron production in lepton-hadron scattering

    SciTech Connect

    Mongan, T.R.

    1982-05-01

    A two-fireball model for hadron production, related to the model developed in Phys. Rev. D 20, 1093 (1979), reproduces the average charged-secondary-hadron multiplicity and the dispersion D = (-/sup 2/)/sup 1/2/ observed in deep-inelastic neutrino-proton scattering.

  2. Leading proton production in deep inelastic scattering at HERA

    E-print Network

    ZEUS Collaboration

    2008-12-12

    The semi-inclusive reaction e+ p -> e+ X p was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb-1. The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, xL>0.32, and its transverse momentum squared satisfied pT^2proton system was 45proton production cross section and rates are presented as a function of xL, pT^2, Q^2 and the Bjorken scaling variable, x.

  3. Patterns of accumulation of miRNAs encoded by herpes simplex virus during productive infection, latency, and on reactivation

    PubMed Central

    Du, Te; Han, Zhiyuan; Zhou, Grace; Roizman, Bernard

    2015-01-01

    The key events in herpes simplex virus (HSV) infections are (i) replication at a portal of entry into the body modeled by infection of cultured cells; (ii) establishment of a latent state characterized by a sole latency-associated transcript and microRNAs (miRNAs) modeled in murine peripheral ganglia 30 d after inoculation; and (iii) reactivation from the latent state modeled by excision and incubation of ganglia in medium containing anti-NGF antibody for a timespan of a single viral replicative cycle. In this report, we examine the pattern of synthesis and accumulation of 18 HSV-1 miRNAs in the three models. We report the following: (i) H2-3P, H3-3P, H4-3P, H5-3P, H6-3P, and H7-5P accumulated in ganglia harboring latent virus. All but H4-3P were readily detected in productively infected cells, and most likely they originate from three transcriptional units. (ii) H8-5P, H15, H17, H18, H26, and H27 accumulated during reactivation. Of this group, only H26 and H27 could be detected in productively infected cells. (iii) Of the 18 we have examined, only 10 miRNAs were found to accumulate above background levels in productively infected cells. The disparity in the accumulation of miRNAs in cell culture and during reactivation may reflect differences in the patterns of regulation of viral gene expression during productive infection and during reactivation from the latent state. PMID:25535379

  4. Chemical Characterization and Reactivity Testing of Fuel-Oxidizer Reaction Product (Test Report)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The product of incomplete reaction of monomethylhydrazine (MMH) and nitrogen tetroxide (NTO) propellants, or fuel-oxidizer reaction product (FORP), has been hypothesized as a contributory cause of an anomaly which occurred in the chamber pressure (PC) transducer tube on the Reaction Control Subsystem (RCS) aft thruster 467 on flight STS-51. A small hole was found in the titanium-alloy PC tube at the first bend below the pressure transducer. It was surmised that the hole may have been caused by heat and pressure resulting from ignition of FORP. The NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) was requested to define the chemical characteristics of FORP, characterize its reactivity, and simulate the events in a controlled environment which may have lead to the Pc-tube failure. Samples of FORP were obtained from the gas-phase reaction of MMH with NTO under laboratory conditions, the pulsed firings of RCS thrusters with modified PC tubes using varied oxidizer or fuel lead times, and the nominal RCS thruster firings at WSTF and Kaiser-Marquardt. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), ion chromatography (IC), inductively coupled plasma (ICP) spectrometry, thermogravimetric analysis (TGA) coupled to FTIR (TGA/FTIR), and mechanical impact testing were used to qualitatively and quantitatively characterize the chemical, thermal, and ignition properties of FORP. These studies showed that the composition of FORP is variable but falls within a limited range of compositions that depends on the fuel loxidizer ratio at the time of formation, composition of the post-formation atmosphere (reducing or oxidizing), and reaction or postreaction temperature. A typical composition contains methylhydrazinium nitrate (MMHN), ammonium nitrate (AN), methylammonium nitrate (MAN), and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. The thermal decomposition reactions of FORP compositions used in this study were unremarkable, Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant-system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid MMH and liquid NTO in a confined space. The test hardware was constructed with pressure- and temperature-measurement devices to determine if the expected fuel oxidizer reaction would result in increased energy release when FORP, FORP constituents, or propellant-system corrosion products were present. These tests demonstrated that FORP, MMHN, AN, or Inconel corrosion products can induce a mixture of MMH and NTO to produce component-damaging energies. The simulation-test program was not extensive enough to provide statistical probabilities for these events but did show that such events can occur. Damaging events required FORP or metal salts to be present at the initial mixing of MMH and NTO. Based on the results of these studies, it is suggested that removal or mitigation of a buildup of these materials may decrease the incidence of these high-energy, potentially damaging events.

  5. On the Temperature Dependence of Organic Reactivity, Ozone Production, and the Impact of Emissions Controls in San Joaquin Valley California

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Gentner, D. R.; Wooldridge, P. J.; Browne, E. C.; Min, K.; Rollins, D. W.; Russell, A.; Thomas, J.; Zhang, L.; Brune, W. H.; Henry, S. B.; DiGangi, J. P.; Keutsch, F. N.; Harrold, S.; Thornton, J. A.; Beaver, M. R.; St Clair, J. M.; Wennberg, P. O.; Ren, X.; Sanders, J.; VandenBoer, T. C.; Markovic, M. Z.; Guha, A.; Weber, R.; Goldstein, A. H.; Cohen, R. C.

    2013-12-01

    The San Joaquin Valley (SJV) experiences some of the worst ozone air quality in the U.S., frequently exceeding the California 8-h standard of 70.4 ppb. To improve our understanding of trends in the number of ozone violations in the SJV, we investigate observed relationships between organic reactivity, nitrogen oxides (NOx), and daily maximum temperature in the southern SJV using measurements made as part of California at the Nexus of Air Quality and Climate Change in 2010 (CalNex-SJV). We find the daytime speciated organic reactivity with respect OH during CalNex-SJV has a temperature-independent portion with molecules typically associated with motor vehicles being the major component. At high temperatures, characteristic of days with high ozone, the majority of the organic reactivity increases exponentially with temperature and is dominated by small oxygenated organics and molecules that are unidentified. We use this simple temperature classification to consider changes in organic emissions over the last and next decade. With the CalNex-SJV observations as constraints, we examine the sensitivity of ozone production (PO3) to future NOx and organic reactivity controls, finding that PO3 is NOx-limited at all temperatures on weekends and on weekdays when daily maximum temperatures are greater than 28oC. As a consequence, we show NOx reductions are the most effective control option for reducing the frequency of ozone violations in the southern SJV.

  6. Stress induced lipid production in Chlorella vulgaris: relationship with specific intracellular reactive species levels.

    PubMed

    Menon, Kavya R; Balan, Ranjini; Suraishkumar, G K

    2013-06-01

    Microalgae have significant potential to be an important alternative energy source, but the challenges to the commercialization of bio-oil from microalgae need to be overcome for the potential to be realized. The application of stress can be used to improve bio-oil yields from algae. Nevertheless, the understanding of stress effects is fragmented due to the lack of a suitable, direct quantitative marker for stress. The lack of understanding seems to have limited the development of stress based strategies to improve bio-oil yields, and hence the commercialization of microalgae-based bio-oil. In this study, we have proposed and used the specific intracellular reactive species levels (siROS) particularly hydroxyl and superoxide radical levels, separately, as direct, quantitative, markers for stress, irrespective of the type of stress induced. Although ROS reactions are extremely rapid, the siROS level can be assumed to be at pseudo-steady state compared to the time scales of metabolism, growth and production, and hence they can be effective stress markers at particular time points. Also, the specific intracellular (si-) hydroxyl and superoxide radical levels are easy to measure through fluorimetry. Interestingly, irrespective of the conditions employed in this study, that is, nutrient excess/limitation or different light wavelengths, the cell concentrations are correlated to the siROS levels in an inverse power law fashion. The composite plots of cell concentration (y) and siROS (x) yielded the correlations of y?=?k1 ?·?x(-0.7) and y?=?k2 ?·?x(-0.79) , for si-hydroxyl and si-superoxide radical levels, respectively. The specific intracellular (si-) neutral lipid levels, which determine the bio-oil productivity, are related in a direct power law fashion to the specific hydroxyl radical levels. The composite plot of si-neutral lipid levels (z) and si-hydroxyl radical level (x) yielded a correlation of z?=?k3 ?·?x(0.65) . More interestingly, a nutrient shift caused a significant change in the sensitivity of neutral lipid accumulation to the si-hydroxyl radical levels. PMID:23297178

  7. Imaging the proton via hard exclusive production in diffractive pp scattering

    SciTech Connect

    Charles Hyde; Leonid Frankfurt; Mark Strikman; Christian Weiss

    2007-05-21

    We discuss the prospects for probing Generalized Parton Distributions (GPDs) via exclusive production of a high-mass system (H = heavy quarkonium, di-photon, di-jet, Higgs boson) in diffractive pp scattering, pp -> p + H + p. In such processes the interplay of hard and soft interactions gives rise to a diffraction pattern in the final-state proton transverse momenta, which is sensitive to the transverse spatial distribution of partons in the colliding protons. We comment on the plans for diffractive pp measurements at RHIC and LHC. Such studies could complement future measurements of GPDs in hard exclusive ep scattering (JLab, COMPASS, EIC).

  8. Evaluating the double parton scattering contribution to Mueller-Navelet jets production at the LHC

    NASA Astrophysics Data System (ADS)

    Ducloué, B.; Szymanowski, L.; Wallon, S.

    2015-10-01

    We propose a model to study the importance of double parton scattering (DPS) in Mueller-Navelet jets production at the LHC which is consistent with the Balitsky-Fadin-Kuraev-Lipatov framework used to compute the single parton scattering contribution to this process. We study this model in kinematics corresponding to existing and possible future measurements at the LHC and estimate the importance of this DPS contribution on relevant observables for this process, namely the cross section and the azimuthal correlation of the jets.

  9. Effects of moderate electrical stimulation on reactive species production by primary rat skeletal muscle cells: cross talk between superoxide and nitric oxide production.

    PubMed

    Lambertucci, Rafael Herling; Silveira, Leonardo Dos Reis; Hirabara, Sandro Massao; Curi, Rui; Sweeney, Gary; Pithon-Curi, Tania Cristina

    2012-06-01

    The effects of a moderate electrical stimulation on superoxide and nitric oxide production by primary cultured skeletal muscle cells were evaluated. The involvement of the main sites of these reactive species production and the relationship between superoxide and nitric oxide production were also examined. Production of superoxide was evaluated by cytochrome c reduction and dihydroethidium oxidation assays. Electrical stimulation increased superoxide production after 1?h incubation. A xanthine oxidase inhibitor caused a partial decrease of superoxide generation and a significant amount of mitochondria-derived superoxide was also observed. Nitric oxide production was assessed by nitrite measurement and by using 4,5-diaminofluorescein diacetate (DAF-2-DA) assay. Using both methods an increased production of nitric oxide was obtained after electrical stimulation, which was also able to induce an increase of iNOS content and NF-?B activation. The participation of superoxide in nitric oxide production was investigated by incubating cells with DAF-2-DA in the presence or absence of electrical stimulation, a superoxide generator system (xanthine-xanthine oxidase), a mixture of NOS inhibitors and SOD-PEG. Our data show that the induction of muscle contraction by a moderate electrical stimulation protocol led to an increased nitric oxide production that can be controlled by superoxide generation. The cross talk between these reactive species likely plays a role in exercise-induced maintenance and adaptation by regulating muscular glucose metabolism, force of contraction, fatigue, and antioxidant systems activities. PMID:21898396

  10. Moderate dependence of reactive oxygen species production on membrane potential in avian muscle mitochondria oxidizing glycerol 3-phosphate.

    PubMed

    Kikusato, Motoi; Toyomizu, Masaaki

    2015-11-01

    Mitochondria are a major source of reactive oxygen species production in cells, and the production level is sensitive to the magnitude of the membrane potential (??). The present study investigated the level of superoxide production in mitochondria oxidizing glycerol 3-phosphate (GP) and its dependence on ?? in isolated avian muscle mitochondria. The levels of superoxide produced in mitochondria oxidizing GP were lower than those obtained with succinate and were similar to those obtained with NADH-linked substrates (glutamate/malate/pyruvate). The dependence of superoxide production on ?? in mitochondria oxidizing GP was lower than that of mitochondria oxidizing succinate, and a weak dependence of GP-supported superoxide production on ?? was observed in the presence of NADH-linked substrates or succinate. These results suggest that the levels of superoxide generated in response to GP are quantitatively low, but they are unsusceptible to changes in ?? in avian muscle mitochondria. PMID:26335765

  11. Dynamical Model of Coherent Pion Production in Neutrino-Nucleus Scattering

    E-print Network

    Nakamura, S X; Lee, T -S H; Szczerbinska, B; Kubodera, K

    2009-01-01

    We study coherent pion production in neutrino-nucleus scattering in the energy region relevant to neutrino oscillation experiments of current interest. Our approach is based on a combined use of the Sato-Lee model of electroweak pion production on a nucleon and the Delta-hole model of pion-nucleus reactions. Thus we develop a model which describes pion-nucleus scattering and electroweak coherent pion production in a unified manner. Numerical calculations are carried out for the case of the 12C target. All the free parameters in our model are fixed by fitting to both total and elastic differential cross sections for pi-12C scattering. Then we demonstrate the reliability of our approach by confronting our prediction for the coherent pion photo-productions with data. Finally, we calculate total and differential cross sections for neutrino-induced coherent pion production, and some of the results are (will be) compared with the recent (forthcoming) data from K2K, SciBooNE and MiniBooNE. We also study effect of th...

  12. Studying re-scattering effect in heavy-ion collision through K* production

    NASA Astrophysics Data System (ADS)

    Singha, Subhash; Mohanty, Bedangadas; Lin, Zi-Wei

    2015-05-01

    We have studied the K* production within a multi-phase transport model (AMPT) for Au+Au collisions at ? {sNN} = 200 GeV to understand the hadronic re-scattering effect on the measured yields of the resonance. The hadronic re-scattering of the K* decay daughter particles (? and K) will alter their momentum distribution thereby making it difficult to reconstruct the K* signal through the invariant mass method. An increased hadronic re-scattering effect thus leads to a decrease in the reconstructed yield of K* in the heavy-ion collisions. Through this simulation study, we argue that a decrease in K*/K ratio with the increase in collision centrality necessarily reflects the hadronic re-scattering effect. Since the re-scattering occurs in the hadronic phase and K* has a lifetime of 4 fm/c, we present a toy model-based discussion on using measured K*/K to put a lower limit on the hadronic phase lifetime in high energy nuclear collisions.

  13. Loss of Memory in H + CH4 ? H2 + CH3 State-to-State Reactive Scattering.

    PubMed

    Welsch, Ralph; Manthe, Uwe

    2015-02-01

    State-to-state reaction probabilities for the H + CH4? H2 + CH3 reaction are calculated by accurate full-dimensional quantum dynamics calculations employing the multilayer multiconfigurational time-dependent Hartree approach and the quantum transition-state concept. Reactions starting from different vibrational and rotational states of the methane reactant are investigated for vanishing total angular momentum. The vibrational state distributions of the products are found to be essentially independent of the initial rovibrational state of the reactants. The reaction products only show vibrational excitation in the methyl umbrella mode. No excitation in H2 vibration or another CH3 vibration is observed. Analyzing the results, the observed loss of vibrational memory can be explained by a transition-state-based view of the reaction process. PMID:26261943

  14. Pion scattering and electro-production on nucleons in the resonance region in chiral quark models

    E-print Network

    Simon Sirca; Bojan Golli; Manuel Fiolhais; Pedro Alberto

    2011-09-01

    Pion scattering and electro-production amplitudes have been computed in a coupled-channel framework incorporating quasi-bound quark-model states, based on the Cloudy Bag model. All relevant low-lying nucleon resonances in the P33, P11, and S11 partial waves have been covered, including the Delta(1232), the N*(1440), N*(1535), and N*(1650). Consistent results have been obtained for elastic and inelastic scattering (two-pion, eta-N, and K-Lambda channels), as well as for electro-production. The meson cloud has been shown to play a major role, in particular in electro-magnetic observables in the P33 and P11 channels.

  15. Coherent anti-Stokes Raman scattering (CARS) detection or hot atom reaction product internal energy distributions

    SciTech Connect

    Quick, C.R. Jr.; Moore, D.S.

    1983-01-01

    Coherent anti-Stokes Raman spectroscopy (CARS) is being utilized to investigate the rovibrational energy distributions produced by reactive and nonreactive collisions of translationally hot atoms with simple molecules. Translationally hot H atoms are produced by ArF laser photolysis of HBr. Using CARS we have monitored, in a state-specific and time-resolved manner, rotational excitation of HBr (v = 0), vibrational excitation of HBr and H/sub 2/, rovibrational excitation of H/sub 2/ produced by the reaction H + HBr ..-->.. H/sub 2/ + Br, and Br atom production by photolysis of HBr.

  16. Interaction of insulin with methyl tert-butyl ether promotes molten globule-like state and production of reactive oxygen species.

    PubMed

    Valipour, Masoumeh; Maghami, Parvaneh; Habibi-Rezaei, Mehran; Sadeghpour, Mostafa; Khademian, Mohamad Ali; Mosavi, Khadijeh; Sheibani, Nader; Moosavi-Movahedi, Ali Akbar

    2015-09-01

    Interaction of methyl tert-butyl ether (MTBE) with proteins is a new look at its potential adverse biological effects. When MTBE is released to the environment it enters the blood stream through inhalation, and could affect the properties of various proteins. Here we investigated the interaction of MTBE with insulin and its effect on insulin structural changes. Our results showed that insulin formed a molten globule (MG)-like structure in the presence of 8 ?M MTBE under physiological pH. The insulin structural changes were studied using spectroscopy methods, viscosity calculation, dynamic light scattering and differential scanning calorimetry. To delineate the mechanisms involved in MTBE-protein interactions, the formation of reactive oxygen specious (ROS) and formation of protein aggregates were measured. The chemiluminscence experiments revealed an increase in ROS production in the presence of MTBE especially in the MG-like state. These results were further confirmed by the aggregation tests, which indicated more aggregation of insulin at 40 ?M MTBE compared with 8 ?M. Thus, the formation of initial aggregates and exposure of the hydrophobic patches upon formation of the MG-like state in the presence of MTBE drives protein oxidation and ROS generation. PMID:26193678

  17. Elastic scattering and ?-particle production in 6He + 208Pb collisions at 22 MeV

    NASA Astrophysics Data System (ADS)

    Acosta, L.; Sánchez-Benítez, A. M.; Gómez, M. E.; Martel, I.; Pérez-Bernal, F.; Pizarro, F.; Rodríguez-Quintero, J.; Rusek, K.; Alvarez, M. A. G.; Andrés, M. V.; Espino, J. M.; Fernández-García, J. P.; Gómez-Camacho, J.; Moro, A. M.; Angulo, C.; Cabrera, J.; Casarejos, E.; Demaret, P.; Borge, M. J. G.; Escrig, D.; Tengblad, O.; Cherubini, S.; Figuera, P.; Gulino, M.; Freer, M.; Metelko, C.; Ziman, V.; Raabe, R.; Mukha, I.; Smirnov, D.; Kakuee, O. R.; Rahighi, J.

    2011-10-01

    Experimental results of the elastic scattering of 6He on 208Pb at ELAB=22 MeV, measured at the CRC facility (Louvain-la-Neuve, Belgium), are presented, including results on the 4He production channel. These data were taken with full angular coverage and high angular resolution. Both experimental cross sections are compared with continuum discretized coupled channels and distorted-wave Born approximation calculations, where direct breakup and transfer to the continuum processes are considered. The elastic data confirm the absence of the Coulomb rainbow, while the distribution of ? particles indicates that such production is mostly generated by transfer to the continuum.

  18. Controlling reactivity of nanoporous catalyst materials by tuning reaction product-pore interior interactions: Statistical mechanical modeling

    SciTech Connect

    Wang, Jing; Ackerman, David M.; Lin, Victor S.-Y.; Pruski, Marek; Evans, James W.

    2013-04-02

    Statistical mechanical modeling is performed of a catalytic conversion reaction within a functionalized nanoporous material to assess the effect of varying the reaction product-pore interior interaction from attractive to repulsive. A strong enhancement in reactivity is observed not just due to the shift in reaction equilibrium towards completion but also due to enhanced transport within the pore resulting from reduced loading. The latter effect is strongest for highly restricted transport (single-file diffusion), and applies even for irreversible reactions. The analysis is performed utilizing a generalized hydrodynamic formulation of the reaction-diffusion equations which can reliably capture the complex interplay between reaction and restricted transport.

  19. D^* production in deep-inelastic scattering at low Q^2

    SciTech Connect

    Jung, Andreas W.; /Fermilab

    2011-07-01

    Inclusive production of D* mesons in deep-inelastic scattering at HERA is studied in the range 5 < Q{sup 2} < 100 GeV{sup 2} of the photon virtuality and 0.02 < y < 0.70 of the inelasticity of the scattering process. The visible range for the D* meson is p{sub T} (D*) > 1.25 GeV and |{eta}(D*)| < 1.8. The data were taken with the H1 detector in the years 2004 to 2007 and correspond to an integrated luminosity of 347 pb{sup -1}. Single and double differential cross sections are measured. The results are compared to QCD predictions.

  20. Measurement of D meson production in ep scattering at low Q

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Miglioranzi, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Rinaldi, L.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Paul, E.; Renner, R.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Namsoo, T.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Blohm, C.; Bonato, A.; Borras, K.; Coppola, N.; Dossanov, A.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Kahle, B.; Klein, U.; Kötz, U.; Kowalski, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Montanari, A.; Notz, D.; Nuncio-Quiroz, A. E.; Rubinsky, I.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Ferrando, J.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Katkov, I. I.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Korcsak-Gorzo, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Ciesielski, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Kuze, M.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Hall-Wilton, R.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Targett-Adams, C.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.; ZEUS Collaboration

    2007-05-01

    The production of D(2010) mesons in ep scattering in the range of exchanged photon virtuality 0.05scattered electron. Differential D cross sections as functions of Q, inelasticity, y, transverse momentum of the D meson, p(D), and pseudorapidity of the D meson, ?(D), have been measured in the kinematic region 0.02

  1. Single-inclusive production of hadrons and jets in lepton-nucleon scattering at NLO

    NASA Astrophysics Data System (ADS)

    Hinderer, Patriz; Schlegel, Marc; Vogelsang, Werner

    2015-07-01

    We present next-to-leading order (NLO) perturbative-QCD calculations of the cross sections for ?N ?h X and ?N ?jet X . The main feature of these processes is that the scattered lepton is not observed, so that the hard scale that makes them perturbative is set by the transverse momentum of the hadron or jet. Kinematically, the two processes thus become direct analogs of single-inclusive production in hadronic collisions which, as has been pointed out in the literature, makes them promising tools for exploring transverse spin phenomena in QCD when the incident nucleon is transversely polarized. We find that the NLO corrections are sizable for the spin-averaged cross section. We also investigate in how far the scattering is dominated by the exchange of almost real (Weizsäcker-Williams) photons. We present numerical estimates of the cross sections for present-day fixed target experiments and for a possible future electron-ion collider.

  2. The impact of dehydration rate on the production and cellular location of reactive oxygen species in an aquatic moss

    PubMed Central

    Cruz de Carvalho, Ricardo; Catalá, Myriam; Marques da Silva, Jorge; Branquinho, Cristina; Barreno, Eva

    2012-01-01

    Background and Aims The aquatic moss Fontinalis antipyretica requires a slow rate of dehydration to survive a desiccation event. The present work examined whether differences in the dehydration rate resulted in corresponding differences in the production of reactive oxygen species (ROS) and therefore in the amount of cell damage. Methods Intracellular ROS production by the aquatic moss was assessed with confocal laser microscopy and the ROS-specific chemical probe 2,7-dichlorodihydrofluorescein diacetate. The production of hydrogen peroxide was also quantified and its cellular location was assessed. Key Results The rehydration of slowly dried cells was associated with lower ROS production, thereby reducing the amount of cellular damage and increasing cell survival. A high oxygen consumption burst accompanied the initial stages of rehydration, perhaps due to the burst of ROS production. Conclusions A slow dehydration rate may induce cell protection mechanisms that serve to limit ROS production and reduce the oxidative burst, decreasing the number of damaged and dead cells due upon rehydration. PMID:22875812

  3. Identification of 4-quinolone derivatives as inhibitors of reactive oxygen species production from human umbilical vein endothelial cells.

    PubMed

    Onda, Kenichi; Narazaki, Fumie; Ishibashi, Naoki; Nakanishi, Keita; Sawada, Yuki; Imamura, Ken-ichiro; Momose, Kazuhiro; Furukawa, Shigetada; Shimada, Yoshiaki; Moriguchi, Hiroyuki; Yuda, Masamichi; Kayakiri, Hiroshi; Ohta, Mitsuaki

    2011-11-15

    Oxidative stress is widely recognized as being associated with a number of disorders, including metabolic dysfunction and atherosclerosis. A series of substituted 4-quinolone derivatives were prepared and evaluated as inhibitors of reactive oxygen species (ROS) production from human umbilical vein endothelial cells (HUVECs). One compound in particular, 2-({[4-(3-hydroxy-3-methylbutoxy)pyridin-2-yl]oxy}methyl)-3-methylquinolin-4(1H)-one (25b), inhibited ROS production from HUVECs with an IC(50) of 140 nM. This compound also exhibited low CYP2D6 inhibitory activity, high aqueous solubility, and good in vitro metabolic stability. An in vivo pharmacokinetic study of this compound in SD rats revealed high oral bioavailability and a long plasma half-life. PMID:21963985

  4. Smac mimetic with TNF-? targets Pim-1 isoforms and reactive oxygen species production to abrogate transformation from blebbishields.

    PubMed

    Jinesh, Goodwin G; Laing, Naomi M; Kamat, Ashish M

    2016-01-01

    Cancer cells are capable of sphere formation (transformation) through reactive oxygen species (ROS) and glycolysis shift. Transformation is linked to tumorigenesis and therapy resistance, hence targeting regulators of ROS and glycolysis is important for cancer therapeutic candidates. Here, we demonstrate that Smac mimetic AZ58 in combination with tumour necrosis factor-? (TNF-?) was able to inhibit the production of ROS, inhibit glycolysis through Pim-1 kinase-mediated Ser-112 phosphorylation of BAD, and increase depolarization of mitochondria. We also identified mitochondrial isoforms of Pim-1 kinase that were targeted for degradation by AZ58 in combination with TNF-? or AZ58 in combination with Fas ligand (FasL) plus cycloheximide (CHX) through caspase-3 to block transformation. Our study demonstrates that Smac mimetic in combination with TNF-? is an ideal candidate to target Pim-1 expression, inhibit ROS production and to block transformation from blebbishields. PMID:26508734

  5. Streptococcus sanguinis induces foam cell formation and cell death of macrophages in association with production of reactive oxygen species.

    PubMed

    Okahashi, Nobuo; Okinaga, Toshinori; Sakurai, Atsuo; Terao, Yutaka; Nakata, Masanobu; Nakashima, Keisuke; Shintani, Seikou; Kawabata, Shigetada; Ooshima, Takashi; Nishihara, Tatsuji

    2011-10-01

    Streptococcus sanguinis, a normal inhabitant of the human oral cavity, is a common streptococcal species implicated in infective endocarditis. Herein, we investigated the effects of infection with S. sanguinis on foam cell formation and cell death of macrophages. Infection with S. sanguinis stimulated foam cell formation of THP-1, a human macrophage cell line. At a multiplicity of infection >100, S. sanguinis-induced cell death of the macrophages. Viable bacterial infection was required to trigger cell death because heat-inactivated S. sanguinis did not induce cell death. The production of cytokines interleukin-1? and tumor necrosis factor-? from macrophages was also stimulated during bacterial infection. Inhibition of the production of reactive oxygen species (ROS) resulted in reduced cell death, suggesting an association of ROS with cell death. Furthermore, S. sanguinis-induced cell death appeared to be independent of activation of inflammasomes, because cleavage of procaspase-1 was not evident in infected macrophages. PMID:22092716

  6. NADPH oxidase activity and reactive oxygen species production in brain and kidney of adult male hypertensive Ren-2 transgenic rats.

    PubMed

    Vokurková, M; Rauchová, H; ?ezá?ová, L; Van??ková, I; Zicha, J

    2015-12-29

    Hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play an important role in brain control of blood pressure (BP). One of the important mechanisms involved in the pathogenesis of hypertension is the elevation of reactive oxygen species (ROS) production by nicotine adenine dinucleotide phosphate (NADPH) oxidase. The aim of our present study was to investigate NADPH oxidase-mediated superoxide (O(2)(-)) production and to search for the signs of lipid peroxidation in hypothalamus and medulla oblongata as well as in renal medulla and cortex of hypertensive male rats transgenic for the murine Ren-2 renin gene (Ren-2 TGR) and their age-matched normotensive controls - Hannover Sprague Dawley rats (HanSD). We found no difference in the activity of NADPH oxidase measured as a lucigenin-mediated O(2)(-) production in the hypothalamus and medulla oblongata. However, we observed significantly elevated NADPH oxidase in both renal cortex and medulla of Ren-2 TGR compared with HanSD. Losartan (LOS) treatment (10 mg/kg body weight/day) for 2 months (Ren-2 TGR+LOS) did not change NADPH oxidase-dependent O(2)(-) production in the kidney. We detected significantly elevated indirect markers of lipid peroxidation measured as thiobarbituric acid-reactive substances (TBARS) in Ren-2 TGR, while they were significantly decreased in Ren-2 TGR+LOS. In conclusion, the present study shows increased NADPH oxidase activities in renal cortex and medulla with significantly increased TBARS in renal cortex. No significant changes of NADPH oxidase and markers of lipid peroxidation were detected in the studied brain regions. PMID:26713567

  7. Double-scattering mechanism of production of two $?^0$ mesons in ultraperipheral, ultrarelativistic heavy ion collisions

    E-print Network

    Antoni Szczurek; Mariola Klusek-Gawenda

    2015-10-13

    We study, for the first time, differential distributions for two $\\rho^0$ meson production in exclusive ultraperipheral, ultrarelativistic heavy ion collisions via a double-scattering mechanism. The calculations are done in the impact parameter space. The cross section for $\\gamma A \\to \\rho^0 A$ is parametrized based on an existing model. Smearing of $\\rho^0$ masses is taken into account. The results of calculations for single and double-$\\rho^0$ production are compared to experimental data at the RHIC and LHC energies. The mechanism considered gives a significant contribution to the $AA \\to AA \\pi^+\\pi^-\\pi^+\\pi^-$ reaction. Some observables related to charged pions are presented too. We compare results of our calculations with the STAR collaboration results for four charged pion production.

  8. Deeply Virtual Compton Scattering and Meson Production at Jlab/CLAS

    SciTech Connect

    Hyon-Suk Jo

    2012-04-01

    This report reviews the recent experimental results from the CLAS collaboration (Hall B of Jefferson Lab, or JLab) on Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP) and discusses their interpretation in the framework of Generalized Parton Distributions (GPDs). The impact of the experimental data on the applicability of the GPD mechanism to these exclusive reactions is discussed. Initial results obtained from JLab 6 GeV data indicate that DVCS might already be interpretable in this framework while GPD models fail to describe the exclusive meson production (DVMP) data with the GPD parameterizations presently used. An exception is the {phi} meson production for which the GPD mechanism appears to apply. The recent global analyses aiming to extract GPDs from fitting DVCS CLAS and world data are discussed. The GPD experimental program at CLAS12, planned with the upcoming 12 GeV upgrade of JLab, is briefly presented.

  9. Production of $c \\bar c$ pairs at LHC: $k_t$-factorization and double-parton scattering

    E-print Network

    Antoni Szczurek

    2012-06-01

    We discuss charm production at LHC. The production of single $c \\bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. Differential distributions for several charmed mesons are presented and compared to recent results of the ALICE and LHCb collaborations. Some missing strength can be observed. Furthermore we discuss production of two $c \\bar c$ pairs within a simple formalism of double-parton scattering (DPS). Surprisingly large cross sections, comparable to single-parton scattering (SPS) contribution to $c \\bar c$ production, are predicted for LHC energies.

  10. Heavy Quarkonium Production in Single Transverse Polarized HighEnergy Scattering

    SciTech Connect

    Yuan, Feng

    2008-01-17

    We formulate the single transverse spin asymmetry in heavyquarkoniumproduction in lepton-nucleon and nucleon-nucleon collisionsinthe non-relativistic limit. We findthat the asymmetry is very sensitiveto the production mechanism. The finalstate interactions with the heavyquark and antiquark cancel out among themselves whenthe pair are producedin a color-single configuration, or cancel out with the initialstateinteraction in pp scattering when they are in color-octet. As aconsequence, the asymmetry is nonzero in ep collisions only in thecolor-octet model, whereas in pp collisions only in the color-singletmodel.

  11. A phenomenological study of photon production in low energy neutrino nucleon scattering

    SciTech Connect

    Jenkins, James P; Goldman, Terry J

    2009-01-01

    Low energy photon production is an important background to many current and future precision neutrino experiments. We present a phenomenological study of t-channel radiative corrections to neutral current neutrino nucleus scattering. After introducing the relevant processes and phenomenological coupling constants, we will explore the derived energy and angular distributions as well as total cross-section predictions along with their estimated uncertainties. This is supplemented throughout with comments on possible experimental signatures and implications. We conclude with a general discussion of the analysis in the context of complimentary methodologies. This is based on a talk presented at the DPF 2009 meeting in Detroit MI.

  12. QCD CORRECTIONS TO DILEPTON PRODUCTION NEAR PARTONIC THRESHOLD IN PP SCATTERING.

    SciTech Connect

    SHIMIZU, H.; STERMAN, G.; VOGELSANG, W.; YOKOYA, H.

    2005-10-02

    We present a recent study of the QCD corrections to dilepton production near partonic threshold in transversely polarized {bar p}p scattering, We analyze the role of the higher-order perturbative QCD corrections in terms of the available fixed-order contributions as well as of all-order soft-gluon resummations for the kinematical regime of proposed experiments at GSI-FAIR. We find that perturbative corrections are large for both unpolarized and polarized cross sections, but that the spin asymmetries are stable. The role of the far infrared region of the momentum integral in the resummed exponent and the effect of the NNLL resummation are briefly discussed.

  13. Pentaerythritol Tetranitrate Targeting Myocardial Reactive Oxygen Species Production Improves Left Ventricular Remodeling and Function in Rats With Ischemic Heart Failure.

    PubMed

    Fraccarollo, Daniela; Galuppo, Paolo; Neuser, Jonas; Bauersachs, Johann; Widder, Julian D

    2015-11-01

    Reduced nitric oxide bioavailability contributes to progression of cardiac dysfunction and remodeling in ischemic heart failure. Clinical use of organic nitrates as nitric oxide donors is limited by development of nitrate tolerance and reactive oxygen species formation. We investigated the effects of long-term therapy with pentaerythritol tetranitrate (PETN), an organic nitrate devoid of tolerance, in rats with congestive heart failure after extensive myocardial infarction. Seven days after coronary artery ligation, rats were randomly allocated to treatment with PETN (80 mg/kg BID) or placebo for 9 weeks. Long-term PETN therapy prevented the progressive left ventricular dilatation and improved left ventricular contractile function and relaxation in rats with congestive heart failure. Mitochondrial superoxide anion production was markedly increased in the failing left ventricular myocardium and nearly normalized by PETN treatment. Gene set enrichment analysis revealed that PETN beneficially modulated the dysregulation of mitochondrial genes involved in energy metabolism, paralleled by prevention of uncoupling protein-3, thioredoxin-2, and superoxide dismutase-2 downregulation. Moreover, PETN provided a remarkable protective effect against reactive fibrosis in chronically failing hearts. Mechanistically, induction of heme oxygenase-1 by PETN prevented mitochondrial superoxide generation, NOX4 upregulation, and ensuing formation of extracellular matrix proteins in fibroblasts from failing hearts. In summary, PETN targeting reactive oxygen species generation prevented the changes of mitochondrial antioxidant enzymes and progressive fibrotic remodeling, leading to amelioration of cardiac functional performance. Therefore, PETN might be a promising therapeutic option in the treatment of ischemic heart diseases involving oxidative stress and impairment in nitric oxide bioactivity. PMID:26351025

  14. Effects of volatiles on melt production and reactive flow in the mantle

    E-print Network

    Keller, Tobias

    2015-01-01

    Magmatism in the Earth interior has a significant impact on its dynamic, thermal and compositional evolution. Experimental studies of petrology of mantle melting find that small concentrations of water and carbon dioxide have a significant effect on the solidus temperature and distribution of melting in the upper mantle. However, it has remained unclear what effect small fractions of deep, volatile-rich melts have on melting and melt transport in the shallow asthenosphere. We present a method to simulate the thermochemical evolution of the upper mantle in the presence of volatiles. The method is based on a novel, thermodynamically consistent framework for reactive, disequilibrium, multi-component melting/crystallisation. This is coupled with a system of equations representing conservation of mass, momentum, and energy for a partially molten grain aggregate. Application of this method to upwelling-column models demonstrates that it captures leading-order features of hydrated and carbonated peridotite melting. ...

  15. Production and characterization of thin film group IIIB, IVB and rare earth hydrides by reactive evaporation

    SciTech Connect

    Provo, James L.

    2015-07-15

    A recent short history of reactive evaporation by D. M. Mattox [History Corner—A Short History of Reactive Evaporation, SVC Bulletin (Society of Vacuum Coaters, Spring 2014), p. 50–51] describes various methods for producing oxides, nitrides, carbides, and some compounds, but hydrides were not mentioned. A study was performed in the mid-1970s at the General Electric Company Neutron Devices Department in Largo, FL, by the author to study preparation of thin film hydrides using reactive evaporation and to determine their unique characteristics and properties. Films were produced of scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), and the rare earth praseodymium (Pr), neodymium (Nd), gadolinium (Gd), dysprosium (Dy), and erbium (Er) hydrides by hot crucible filament and electron beam evaporation in atmospheres of deuterium and tritium gases. All-metal vacuum systems were used and those used with tritium were dedicated for this processing. Thin film test samples 1000?nm thick were prepared on 1.27?cm diameter molybdenum disk substrates for each occluder (i.e., an element that can react with hydrogen to form a hydride) material. Loading characteristics as determined by gas-to-metal atomic ratios, oxidation characteristics as determined by argon–sputter Auger analysis, film structure as determined by scanning electron microscope analysis, and film stress properties as determined by a double resonator technique were used to define properties of interest. Results showed hydrogen-to-metal atomic ratios varied from 1.5 to 2.0 with near maximum loading for all but Pr and Nd occluders which correlated with the oxidation levels observed, with all occluder oxidation levels being variable due to vacuum system internal processing conditions and the materials used. Surface oxide levels varied from ?80?Å to over 1000?Å. For most films studied, results showed that a maximum loading ratio of near 2.0 and a minimum surface oxide level of ?80?Å could be obtained with a bulk film oxygen level of ?0.54 oxygen as determined by microprobe analysis when an evaporation rate of ?0.313?mg/cm{sup 2} min was used in an atmosphere of D{sub 2} or T{sub 2} gas at a system deposition pressure of 1?×?10{sup ?3?}Torr (1.33?×?10{sup ?1?}Pa) in an evaporation time of ?2 min. Platelet type (i.e., a film microstructure showing an overlay of flat plates with large grain sizes) film structures were observed for most films with some film mechanical properties determined (i.e., grain size and Vickers ?-hardness), and reduced stress levels were seen with initial normalized differential (tensile) stress levels being (1.0–4.0)?×?10{sup 8?}dyne/cm{sup 2} for tritium loaded samples and (1.5?±?0.5)?×?10{sup 9?}dyne/cm{sup 2} for deuterium loaded samples. Also, stress aging characteristics were determined for some hydride films prepared in a radioactive tritium gas atmosphere. Tritium loading, however, had the undesirable characteristic of having to dispose of the internal processing system fixtures, which can be minimized, but the reactive evaporation technique produced desirable thin films.

  16. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings...

  17. Frequency effects on the production of reactive oxygen species in atmospheric radio frequency helium-oxygen discharges

    SciTech Connect

    Zhang, Yuantao T.; He Jin

    2013-01-15

    Several experimental and computational studies have shown that increasing frequency can effectively enhance the discharge stability in atmospheric radio-frequency (rf) discharges, but the frequency effects on the reactivity of rf discharges, represented by the densities of reactive oxygen species (ROS), are still far from fully understood. In this paper, a one-dimensional fluid model with 17 species and 65 reactions taken into account is used to explore the influences of the driving frequency on the production and destruction of ROS in atmospheric rf helium-oxygen discharges. From the computational results, with an increase in the frequency the densities of ROS decrease always at a constant power density, however, in the relatively higher frequency discharges the densities of ROS can be effectively improved by increasing the input power density with an expanded oxygen admixture range, while the discharges operate in the {alpha} mode, and the numerical data also show the optimal oxygen admixture for ground state atomic oxygen, at which the peak atomic oxygen density can be obtained, increases with the driving frequency.

  18. Arylhydrocarbon receptor (AhR) activation in airway epithelial cells induces MUC5AC via reactive oxygen species (ROS) production.

    PubMed

    Chiba, Takahito; Uchi, Hiroshi; Tsuji, Gaku; Gondo, Hisaki; Moroi, Yoichi; Furue, Masutaka

    2011-02-01

    The dioxins and dioxin-like compounds in cigarette smoke regulate various immunological responses via the arylhydrocarbon receptor (AhR). These environmental toxicants are known to cause bronchitis, asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. Recent studies have demonstrated that AhR activation upregulates the expression of mucin 5AC, oligomeric mucus/gel-forming (MUC5AC) in the airway epithelial cell line. However, the mechanism for the production of mucin has not been clarified. In this study, we investigated the role and pathway of AhR in airway epithelial cells by using selective agonists and antagonists. After stimulation with or without benzopyrene (B[a]P), an AhR agonist, MUC5AC expression was measured by real-time RT-PCR. The mechanism of AhR-induced MUC5AC expression in airway epithelial cells was studied in terms of the production of cytokine and reactive oxygen species (ROS). Treatment with B[a]P increased ROS generation in NCI-H??? cells. Furthermore, B[a]P-induced MUC5AC upregulation and mucin production were inhibited by AhR siRNA or the use of an antioxidative agent. These results suggest that the AhR-induced increase of mucin production is partially mediated by ROS generation. An antioxidant therapy approach may help to cure AhR-induced mucus hypersecretory diseases. PMID:20709182

  19. Effect of an inhaled glucocorticoid on reactive oxygen species production by bronchoalveolar lavage cells from smoking COPD patients.

    PubMed Central

    Verhoeven, G T; Wijkhuijs, A J; Hooijkaas, H; Hoogsteden, H C; Sluiter, W

    2000-01-01

    Oxidative stress in the lung is important in the pathogenesis of COPD. Published data indicate that glucocorticoids inhibit blood cells in their capacity to produce reactive oxygen species (ROS). We investigated the effect of Fluticasone propionate (FP) on the ROS production capabilities of pulmonary cells. Bronchoalveolar lavage (BAL) was performed in smoking COPD patients, before and after a six month, placebo-controlled treatment with FP. BAL cells were stimulated with phorbol myristrate acetate (PMA) alone, and together with superoxide dismutase (SOD). From kinetic plots of ferricytochrome-c conversion we calculated the maximal rate of superoxide production: V(max). We also examined BAL cell subsets and performed correlation analyses on ROS production and relevant clinical determinants. Paired results were obtained from 6 FP- and 9 placebo-treated patients. No significant change of V(max) was found in both patient groups. Also BAL cellularity was unchanged. Correlation analyses showed a significant (inverse) association of V(max) with the number of cigarettes smoked per day. We concluded that a potent inhaled glucocorticoid had no effect on the ROS production capability of BAL cells from smoking COPD patients. Apparently, heavy smoking impaired the ability of alveolar macrophages to produce ROS, which was not further decreased by FP. PMID:10958384

  20. NADPH Oxidase-Dependent Production of Reactive Oxygen Species Induces Endoplasmatic Reticulum Stress in Neutrophil-Like HL60 Cells

    PubMed Central

    Kuwabara, Wilson Mitsuo Tatagiba; Zhang, Liling; Schuiki, Irmgard; Curi, Rui; Volchuk, Allen; Alba-Loureiro, Tatiana Carolina

    2015-01-01

    Reactive oxygen species (ROS) primarily produced via NADPH oxidase play an important role for killing microorganisms in neutrophils. In this study we examined if ROS production in Human promyelocytic leukemia cells (HL60) differentiated into neutrophil-like cells (dHL60) induces ER stress and activates the unfolded protein response (UPR). To cause ROS production cells were treated with PMA or by chronic hyperglycemia. Chronic hyperglycemia failed to induce ROS production and did not cause activation of the UPR in dHL60 cells. PMA, a pharmacologic NADPH oxidase activator, induced ER stress in dHL60 cells as monitored by IRE-1 and PERK pathway activation, and this was independent of calcium signaling. The NADPH oxidase inhibitor, DPI, abolished both ROS production and UPR activation. These results show that ROS produced by NADPH oxidase induces ER stress and suggests a close association between the redox state of the cell and the activation of the UPR in neutrophil-like HL60 cells. PMID:25668518

  1. Reactive oxygen species production has a critical role in hypoxia-induced Stat3 activation and angiogenesis in human glioblastoma.

    PubMed

    Yu, Mi Ok; Park, Kyung-Jae; Park, Dong-Hyuk; Chung, Yong-Gu; Chi, Sung-Gil; Kang, Shin-Hyuk

    2015-10-01

    Glioblastoma is the most aggressive primary brain tumor with hypoxia-associated morphologic features including pseudopalisading necrosis and endothelial hyperplasia. It has been known that hypoxia can activate signal transducer and activator of transcription 3 (Stat3) and subsequently induce angiogenesis. However, the molecular mechanism underlying hypoxia-induced Stat3 activation has not been defined. In this study, we explored the possible implication of reactive oxygen species (ROS) in hypoxia-driven Stat3 activation in human glioblastoma. We found that hypoxic stress increased ROS production as well as Stat3 activation and that ROS inhibitors (diphenyleneiodonium, rotenone and myxothiazol) and an antioxidant (N-acetyl-L-cysteine) blocked Stat3 activation under hypoxic conditions. To determine a major route of ROS production, we tested whether nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) is involved in hypoxia-induced ROS production. Nox4 expression was found to be increased at both mRNA and protein levels in hypoxic glioblastoma cells. In addition, siRNA-mediated knockdown of Nox4 expression abolished hypoxia induced Stat3 activation and vascular endothelial growth factor expression, which is associated with tumor cells' ability to trigger tube formation of endothelial cells in vitro. Our findings indicate that elevated ROS production plays a crucial role for Stat3 activation and angiogenesis in hypoxic glioblastoma cells. PMID:26297045

  2. beta-aminobutyric acid primes an NADPH oxidase-dependent reactive oxygen species production during grapevine-triggered immunity.

    PubMed

    Dubreuil-Maurizi, Carole; Trouvelot, Sophie; Frettinger, Patrick; Pugin, Alain; Wendehenne, David; Poinssot, Benoît

    2010-08-01

    The molecular mechanisms underlying the process of priming are poorly understood. In the present study, we investigated the early signaling events triggered by beta-aminobutyric acid (BABA), a well-known priming-mediated plant resistance inducer. Our results indicate that, in contrast to oligogalacturonides (OG), BABA does not elicit typical defense-related early signaling events nor defense-gene expression in grapevine. However, in OG-elicited cells pretreated with BABA, production of reactive oxygen species (ROS) and expression of the respiratory-burst oxidase homolog RbohD gene were primed. In response to the causal agent of downy mildew Plasmopara viticola, a stronger ROS production was specifically observed in BABA-treated leaves. This process was correlated with an increased resistance. The NADPH oxidase inhibitor diphenylene iodonium (DPI) abolished this primed ROS production and reduced the BABA-induced resistance (BABA-IR). These results suggest that priming of an NADPH oxidase-dependent ROS production contributes to BABA-IR in the Vitis-Plasmopara pathosystem. PMID:20615112

  3. Measurement of D + and ? c + production in deep inelastic scattering at HERA

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Antonelli, S.; Antonioli, P.; Antonov, A.; Arneodo, M.; Aushev, V.; Aushev, Y.; Bachynska, O.; Bamberger, A.; Barakbaev, A. N.; Barbagli, G.; Bari, G.; Barreiro, F.; Bartsch, D.; Basile, M.; Behnke, O.; Behr, J.; Behrens, U.; Bellagamba, L.; Bertolin, A.; Bhadra, S.; Bindi, M.; Blohm, C.; Bold, T.; Boos, E. G.; Borodin, M.; Borras, K.; Boscherini, D.; Bot, D.; Boutle, S. K.; Brock, I.; Brownson, E.; Brugnera, R.; Brümmer, N.; Bruni, A.; Bruni, G.; Brzozowska, B.; Bussey, P. J.; Butterworth, J. M.; Bylsma, B.; Caldwell, A.; Capua, M.; Carlin, R.; Catterall, C. D.; Chekanov, S.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; Cooper-Sarkar, A. M.; Coppola, N.; Corradi, M.; Corriveau, F.; Costa, M.; D'Agostini, G.; Dal Corso, F.; de Favereau, J.; Del Peso, J.; Dementiev, R. K.; de Pasquale, S.; Derrick, M.; Devenish, R. C. E.; Dobur, D.; Dolgoshein, B. A.; Doyle, A. T.; Drugakov, V.; Durkin, L. S.; Dusini, S.; Eisenberg, Y.; Ermolov, P. F.; Eskreys, A.; Fang, S.; Fazio, S.; Ferrando, J.; Ferrero, M. I.; Figiel, J.; Forrest, M.; Foster, B.; Fourletov, S.; Gach, G.; Galas, A.; Gallo, E.; Garfagnini, A.; Geiser, A.; Gialas, I.; Gladilin, L. K.; Gladkov, D.; Glasman, C.; Gogota, O.; Golubkov, Yu. A.; Göttlicher, P.; Grabowska-Bo?d, I.; Grebenyuk, J.; Gregor, I.; Grigorescu, G.; Grzelak, G.; Gwenlan, C.; Haas, T.; Hain, W.; Hamatsu, R.; Hart, J. C.; Hartmann, H.; Hartner, G.; Hilger, E.; Hochman, D.; Holm, U.; Hori, R.; Horton, K.; Hüttmann, A.; Iacobucci, G.; Ibrahim, Z. A.; Iga, Y.; Ingbir, R.; Ishitsuka, M.; Jakob, H.-P.; Januschek, F.; Jimenez, M.; Jones, T. W.; Jüngst, M.; Kadenko, I.; Kahle, B.; Kamaluddin, B.; Kananov, S.; Kanno, T.; Karshon, U.; Karstens, F.; Katkov, I. I.; Kaur, M.; Kaur, P.; Keramidas, A.; Khein, L. A.; Kim, J. Y.; Kisielewska, D.; Kitamura, S.; Klanner, R.; Klein, U.; Koffeman, E.; Kollar, D.; Kooijman, P.; Korol, Ie.; Korzhavina, I. A.; Kota?ski, A.; Kötz, U.; Kowalski, H.; Kulinski, P.; Kuprash, O.; Kuze, M.; Lee, A.; Levchenko, B. B.; Levy, A.; Libov, V.; Limentani, S.; Ling, T. Y.; Lisovyi, M.; Lobodzinska, E.; Lohmann, W.; Löhr, B.; Lohrmann, E.; Loizides, J. H.; Long, K. R.; Longhin, A.; Lontkovskyi, D.; Lukina, O. Yu.; ?u?niak, P.; Maeda, J.; Magill, S.; Makarenko, I.; Malka, J.; Mankel, R.; Margotti, A.; Marini, G.; Martin, J. F.; Mastroberardino, A.; Matsumoto, T.; Mattingly, M. C. K.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Mohamad Idris, F.; Monaco, V.; Montanari, A.; Morris, J. D.; Musgrave, B.; Nagano, K.; Namsoo, T.; Nania, R.; Nicholass, D.; Nigro, A.; Ning, Y.; Noor, U.; Notz, D.; Nowak, R. J.; Nuncio-Quiroz, A. E.; Oh, B. Y.; Okazaki, N.; Oliver, K.; Olkiewicz, K.; Onishchuk, Yu.; Ota, O.; Papageorgiu, K.; Parenti, A.; Paul, E.; Pawlak, J. M.; Pawlik, B.; Pelfer, P. G.; Pellegrino, A.; Perlanski, W.; Perrey, H.; Piotrzkowski, K.; Plucinski, P.; Pokrovskiy, N. S.; Polini, A.; P Roskuryakov, A. S.; Przybycie?, M.; Raval, A.; Reeder, D. D.; Reisert, B.; Ren, Z.; Repond, J.; Ri, Y. D.; Robertson, A.; Roloff, P.; Ron, E.; Rubinsky, I.; Ruspa, M.; Sacchi, R.; Salii, A.; Samson, U.; Sartorelli, G.; Savin, A. A.; Saxon, D. H.; Schioppa, M.; Schlenstedt, S.; Schleper, P.; Schmidke, W. B.; Schneekloth, U.; Schönberg, V.; Schörner-Sadenius, T.; Schwartz, J.; Sciulli, F.; Shcheglova, L. M.; Shehzadi, R.; Shimizu, S.; Singh, I.; Skillicorn, I. O.; Slomi?ski, W.; Smith, W. H.; Sola, V.; Solano, A.; Son, D.; Sosnovtsev, V.; Spiridonov, A.; Stadie, H.; Stanco, L.; Stern, A.; Stewart, T. P.; Stifutkin, A.; Stopa, P.; Suchkov, S.; Susinno, G.; Suszycki, L.; Sztuk, J.; Szuba, D.; Szuba, J.; Tapper, A. D.; Tassi, E.; Terrón, J.; Theedt, T.; Tiecke, H.; Tokushuku, K.; Tomalak, O.; Tomaszewska, J.; Tsurugai, T.; Turcato, M.; Tymieniecka, T.; Uribe-Estrada, C.; Vázquez, M.; Verbytskyi, A.; Viazlo, O.; Vlasov, N. N.; Volynets, O.; Walczak, R.; Wan Abdullah, W. A. T.; Whitmore, J. J.; Whyte, J.; Wiggers, L.; Wing, M.; Wlasenko, M.; Wolf, G.; Wolfe, H.; Wrona, K.; Yagües-Molina, A. A.; Yamada, S.; Yamazaki, Y.; Yoshida, R.; Youngman, C.; ?arnecki, A. A.; Zawiejski, L.; Zenaiev, O.; Zeuner, W.; Zhautykov, B. O.; Zhmak, N.; Zhou, C.; Zichichi, A.; Zolko, M.; Zotkin, D. S.; Zulkapli, Z.

    2010-11-01

    Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb-1. The hadronic decay channels D + ? K S 0 ? +, ? c + ? pK S 0 and ? c + ? ? ? +, and their charge conjugates, were reconstructed. The presence of a neutral strange hadron in the final state reduces the combinatorial background and extends the measured sensitivity into the low transverse momentum region. The kinematic range is 0 < p T ( D +, ? c +) < 10 GeV, | ?( D +, ? c +)| < 1 .6, 1.5 < Q 2 < 1000 GeV2 and 0 .02 < y < 0.7. Inclusive and differential cross sections for the production of D + mesons are compared to next-to-leading-order QCD predictions. The fraction of c quarks hadronising into ? c + baryons is extracted.

  4. Multi-jet production rates in deep-inelastic muon-proton scattering

    SciTech Connect

    Salgado, C.W.; E665 Collaboration

    1992-10-01

    Measurements of forward multi-jet production rates in deep-inelastic muonproton scattering are presented. Data were taken with a 490 GeV muon beam incident on a hydrogen target. Jets were defined using the JADE jet finding algorithm. The measured rates are presented as function of W, the hadronic center-of-mass energy and the jet resolution parameter, y{sub cut}, in energies up to W=33 GeV. Good agreement is found in comparisons with predictions of the QCD-inspired Lund Monte Carlo models. Non-perturbative QCD production mechanisms, inside the Lund Model, can not reproduce the results for energies greater than W {approx_equal} 20 GeV. Sensitivities of the jet rate measurements to the low x (x {approx_equal} 0.02) gluon content of the nucleon and the evolution of {alpha}{sub s}, are studied.

  5. Defining the mechanisms by which the reactive oxygen species by-product, 4-hydroxynonenal, affects human sperm cell function.

    PubMed

    Baker, Mark A; Weinberg, Anita; Hetherington, Louise; Villaverde, Ana-Izabel; Velkov, Tony; Baell, Jonathan; Gordon, Christopher P

    2015-04-01

    Lipid peroxidation products such as the naturally occurring aldehyde 4-hydroxynonenal (4-HNE) are known to be cytotoxic toward different cell types, including spermatozoa. In order to understand this at the molecular level, we have employed a proteomic approach to characterize direct 4-HNE adducts on human spermatozoa. Several proteins were identified to be of particular interest, including aldehyde labeling of histone methyltransferase and dynein heavy chain. In addition, we found that 4-HNE bound to part of the activation segment, cysteine residue 199, of protein kinase A (PKA). Interestingly, at low levels, addition of 4-HNE had a stimulatory effect on PKA. However, this did not correlate to increased phosphotyrosine levels during capacitation. This data explains the link between reactive oxygen species and sperm toxicity. Given that epigenetic regulation is likely affected in oxidative-stressed spermatozoa, this data show that spermatozoa appear to shut down under these conditions before reaching the egg. PMID:25673561

  6. Phenylethynyl reactive diluents

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (inventor.); Jensen, Brian J. (inventor.); Hergenrother, Paul M. (inventor.)

    1995-01-01

    A composition of matter having a specified general structure is employed to terminate a nucleophilic reagent, resulting in the exclusive production of phenylethynyl terminated reactive oligomers which display unique thermal characteristics. A reactive diluent having a specified general structure is employed to decrease the melt viscosity of a phenylethynyl terminated reactive oligomer and to subsequently react with to provide a thermosetting material of enhanced density. These materials have features which make them attractive candidates for use as composite matrices and adhesives.

  7. Hypoxia dysregulates the production of adiponectin and plasminogen activator inhibitor-1 independent of reactive oxygen species in adipocytes

    SciTech Connect

    Chen Baoying; Lam, Karen S.L.; Wang Yu; Wu Donghai; Lam, Michael C.; Shen Jiangang; Wong Laiching; Hoo, Ruby L.C.; Zhang Jialiang; Xu Aimin . E-mail: amxu@hkucc.hku.hk

    2006-03-10

    Low plasma levels of adiponectin (hypoadiponectinemia) and elevated circulating concentrations of plasminogen activator inhibitor (PAI)-1 are causally associated with obesity-related insulin resistance and cardiovascular disease. However, the mechanism that mediates the aberrant production of these two adipokines in obesity remains poorly understood. In this study, we investigated the effects of hypoxia and reactive oxygen species (ROS) on production of adiponectin and PAI-1 in 3T3-L1 adipocytes. Quantitative PCR and immunoassays showed that ambient hypoxia markedly suppressed adiponectin mRNA expression and its protein secretion, and increased PAI-1 production in mature adipocytes. Dimethyloxallyl glycine, a stabilizer of hypoxia-inducible factor 1{alpha} (HIF-1{alpha}), mimicked the hypoxia-mediated modulations of these two adipokines. Hypoxia caused a modest elevation of ROS in adipocytes. However, ablation of intracellular ROS by antioxidants failed to alleviate hypoxia-induced aberrant production of adiponectin and PAI-1. On the other hand, the antioxidants could reverse hydrogen peroxide (H{sub 2}O{sub 2})-induced dysregulation of adiponectin and PAI-1 production. H{sub 2}O{sub 2} treatment decreased the expression levels of peroxisome proliferator-activated receptor gamma (PPAR{gamma}) and CCAAT/enhancer binding protein (C/EBP{alpha}), but had no effect on HIF-1{alpha}, whereas hypoxia stabilized HIF-1{alpha} and decreased expression of C/EBP{alpha}, but not PPAR{gamma}. Taken together, these data suggest that hypoxia and ROS decrease adiponectin production and augment PAI-1 expression in adipocytes via distinct signaling pathways. These effects may contribute to hypoadiponectinemia and elevated PAI-1 levels in obesity, type 2 diabetes, and cardiovascular diseases.

  8. Single Diffractive Lambda_c^+ Production in Polarized pp Scattering with Polarized Gluon Distribution in the Proton

    E-print Network

    Kazumasa Ohkuma; Toshiyuki Morii

    2002-08-01

    Based on the hard-scattering factorization which decomposes the diffractive structure function into a pomeron flux and a pomeron structure function, we study the single diffractive Lambda_c^+ production in polarized pp scattering: p + p -> p + Lambda_c^+ + X, which will be observed at forthcoming RHIC experiment. By analyzing the cross section and correlation of the spin polarization between the initial proton and produced Lambda_c^+, we found that the process is quite effective for testing both hard-scattering factorization and models of the polarized gluon distribution in the proton.

  9. Continuous Production of Biodiesel Via an Intensified Reactive/Extractive Process

    SciTech Connect

    Tsouris, Costas; McFarlane, Joanna; Birdwell Jr, Joseph F; Jennings, Hal L

    2008-01-01

    Biodiesel is considered as a means to diversify our supply of transportation fuel, addressing the goal of reducing our dependence on oil. For a number of reasons ranging from production issues to end use, biodiesel represents only a small fraction of the transportation fuel used worldwide. This work addresses the aspect of biodiesel production that limits it to a slow batch process. Conventional production methods are batch in nature, based on the assumption that the rates of the key chemical reactions are slow. The hypothesis motivating this work is that the reaction kinetics for the transesterification of the reagent triglyceride is sufficiently fast, particularly in an excess of catalyst, and that interfacial mass transfer and phase separation control the process. If this is the case, an intensified two-phase reactor adapted from solvent extraction equipment may be utilized to greatly increase biodiesel production rates by increasing interphase transport and phase separation. To prove this idea, we are investigating two aspects: (1) determining the rate-limiting step in biodiesel production by evaluating the reaction kinetics, and (2) enhancing biodiesel production rates by using an intensified reactor. A centrifugal contactor combining interphase mass transfer, chemical reaction, and phase separation is employed for process intensification.

  10. Entropy and chemical change. 1: Characterization of product (and reactant) energy distributions in reactive molecular collisions: Information and enthropy deficiency

    NASA Technical Reports Server (NTRS)

    Bernstein, R. B.; Levine, R. D.

    1972-01-01

    Optimal means of characterizing the distribution of product energy states resulting from reactive collisions of molecules with restricted distributions of initial states are considered, along with those for characterizing the particular reactant state distribution which yields a given set of product states at a specified total energy. It is suggested to represent the energy-dependence of global-type results in the form of square-faced bar plots, and of data for specific-type experiments as triangular-faced prismatic plots. The essential parameters defining the internal state distribution are isolated, and the information content of such a distribution is put on a quantitative basis. The relationship between the information content, the surprisal, and the entropy of the continuous distribution is established. The concept of an entropy deficiency, which characterizes the specificity of product state formation, is suggested as a useful measure of the deviance from statistical behavior. The degradation of information by experimental averaging is considered, leading to bounds on the entropy deficiency.

  11. Asian Dust Particles Induce Macrophage Inflammatory Responses via Mitogen-Activated Protein Kinase Activation and Reactive Oxygen Species Production

    PubMed Central

    Higashisaka, Kazuma; Fujimura, Maho; Taira, Mayu; Yoshida, Tokuyuki; Tsunoda, Shin-ichi; Baba, Takashi; Yamaguchi, Nobuyasu; Nabeshi, Hiromi; Yoshikawa, Tomoaki; Nasu, Masao; Tsutsumi, Yasuo

    2014-01-01

    Asian dust is a springtime meteorological phenomenon that originates in the deserts of China and Mongolia. The dust is carried by prevailing winds across East Asia where it causes serious health problems. Most of the information available on the impact of Asian dust on human health is based on epidemiological investigations, so from a biological standpoint little is known of its effects. To clarify the effects of Asian dust on human health, it is essential to assess inflammatory responses to the dust and to evaluate the involvement of these responses in the pathogenesis or aggravation of disease. Here, we investigated the induction of inflammatory responses by Asian dust particles in macrophages. Treatment with Asian dust particles induced greater production of inflammatory cytokines interleukin-6 and tumor necrosis factor-? (TNF-?) compared with treatment with soil dust. Furthermore, a soil dust sample containing only particles ?10??m in diameter provoked a greater inflammatory response than soil dust samples containing particles >10??m. In addition, Asian dust particles-induced TNF-? production was dependent on endocytosis, the production of reactive oxygen species, and the activation of nuclear factor-?B and mitogen-activated protein kinases. Together, these results suggest that Asian dust particles induce inflammatory disease through the activation of macrophages. PMID:24987712

  12. Sanguinarine-induced apoptosis in lung adenocarcinoma cells is dependent on reactive oxygen species production and endoplasmic reticulum stress.

    PubMed

    Gu, Shuang; Yang, Xiao-Chun; Xiang, Xi-Yan; Wu, Yao; Zhang, Yu; Yan, Xiao-Yu; Xue, Ya-Nan; Sun, Lian-Kun; Shao, Guo-Guang

    2015-08-01

    Sanguinarine (SAN), an alkaloid isolated from plants of the Papaveraceae family, is a compound with multiple biological activities. In the present study, we explored the anticancer properties of SAN in lung cancer using the human lung adenocarcinoma cell line SPC-A1. Our results revealed that SAN inhibited SPC-A1 cell growth and induced apoptosis in a dose-dependent manner. We found that SAN triggered reactive oxygen species (ROS) production, while elimination of ROS by N-acetylcysteine (NAC) reversed the growth inhibition and apoptosis induced by SAN. SAN-induced endoplasmic reticulum (ER) stress resulted in the upregulation of many genes and proteins involved in the unfolded protein response (UPR) pathway, including glucose-regulated protein 78 (GRP78), p-protein kinase R (PKR)-like ER kinase (PERK), p-eukaryotic translation initiation factor 2? (eIF2?), activating transcription factor 4 (ATF4) and CCAAT/enhancer binding protein homologous protein (CHOP). Blocking ER stress with tauroursodeoxycholic acid (TUDCA) markedly reduced SAN-induced inhibition of growth and apoptosis. Furthermore, TUDCA decreased SAN-induced ROS production, and NAC attenuated SAN-induced GRP78 and CHOP expression. Overall, our data indicate that the anticancer effects of SAN in lung cancer cells depend on ROS production and ER stress and that SAN may be a potential agent against lung cancer. PMID:26081590

  13. Reactive oxygen species production by potato tuber mitochondria is modulated by mitochondrially bound hexokinase activity.

    PubMed

    Camacho-Pereira, Juliana; Meyer, Laudiene Evangelista; Machado, Lilia Bender; Oliveira, Marcus Fernandes; Galina, Antonio

    2009-02-01

    Potato tuber (Solanum tuberosum) mitochondria (PTM) have a mitochondrially bound hexokinase (HK) activity that exhibits a pronounced sensitivity to ADP inhibition. Here we investigated the role of mitochondrial HK activity in PTM reactive oxygen species generation. Mitochondrial HK has a 10-fold higher affinity for glucose (Glc) than for fructose (KMGlc=140 microM versus KMFrc=1,375 microM). Activation of PTM respiration by succinate led to an increase in hydrogen peroxide (H2O2) release that was abrogated by mitochondrial HK activation. Mitochondrial HK activity caused a decrease in the mitochondrial membrane potential and an increase in oxygen consumption by PTM. Inhibition of Glc phosphorylation by mannoheptulose or GlcNAc induced a rapid increase in H2O2 release. The blockage of H2O2 release sustained by Glc was reverted by oligomycin and atractyloside, indicating that ADP recycles through the adenine nucleotide translocator and F0F1ATP synthase is operative during the mitochondrial HK reaction. Inhibition of mitochondrial HK activity by 60% to 70% caused an increase of 50% in the maximal rate of H2O2 release. Inhibition in H2O2 release by mitochondrial HK activity was comparable to, or even more potent, than that observed for StUCP (S. tuberosum uncoupling protein) activity. The inhibition of H2O2 release in PTM was two orders of magnitude more selective for the ADP produced from the mitochondrial HK reaction than for that derived from soluble yeast (Saccharomyces cerevisiae) HK. Modulation of H2O2 release and oxygen consumption by Glc and mitochondrial HK inhibitors in potato tuber slices shows that hexoses and mitochondrial HK may act as a potent preventive antioxidant mechanism in potato tubers. PMID:19109413

  14. A role for human mitochondrial complex II in the production of reactive oxygen species in human skin

    PubMed Central

    Anderson, Alasdair; Bowman, Amy; Boulton, Sarah Jayne; Manning, Philip; Birch-Machin, Mark A.

    2014-01-01

    The mitochondrial respiratory chain is a major generator of cellular oxidative stress, thought to be an underlying cause of the carcinogenic and ageing process in many tissues including skin. Previous studies of the relative contributions of the respiratory chain (RC) complexes I, II and III towards production of reactive oxygen species (ROS) have focussed on rat tissues and certainly not on human skin which is surprising as this tissue is regularly exposed to UVA in sunlight, a potent generator of cellular oxidative stress. In a novel approach we have used an array of established specific metabolic inhibitors and DHR123 fluorescence to study the relative roles of the mitochondrial RC complexes in cellular ROS production in 2 types of human skin cells. These include additional enhancement of ROS production by exposure to physiological levels of UVA. The effects within epidermal and dermal derived skin cells are compared to other tissue cell types as well as those harbouring a compromised mitochondrial status (Rho-zero A549). The results show that the complex II inhibitor, TTFA, was the only RC inhibitor to significantly increase UVA-induced ROS production in both skin cell types (P<0.05) suggesting that the role of human skin complex II in terms of influencing ROS production is more important than previously thought particularly in comparison to liver cells. Interestingly, two-fold greater maximal activity of complex II enzyme was observed in both skin cell types compared to liver (P<0.001). The activities of RC enzymes appear to decrease with increasing age and telomere length is correlated with ageing. Our study showed that the level of maximal complex II activity was higher in the MRC5/hTERT (human lung fibroblasts transfected with telomerase) cells than the corresponding wild type cells (P=0.0012) which can be considered (in terms of telomerase activity) as models of younger and older cells respectively. PMID:25460738

  15. A role for human mitochondrial complex II in the production of reactive oxygen species in human skin.

    PubMed

    Anderson, Alasdair; Bowman, Amy; Boulton, Sarah Jayne; Manning, Philip; Birch-Machin, Mark A

    2014-08-28

    The mitochondrial respiratory chain is a major generator of cellular oxidative stress, thought to be an underlying cause of the carcinogenic and ageing process in many tissues including skin. Previous studies of the relative contributions of the respiratory chain (RC) complexes I, II and III towards production of reactive oxygen species (ROS) have focussed on rat tissues and certainly not on human skin which is surprising as this tissue is regularly exposed to UVA in sunlight, a potent generator of cellular oxidative stress. In a novel approach we have used an array of established specific metabolic inhibitors and DHR123 fluorescence to study the relative roles of the mitochondrial RC complexes in cellular ROS production in 2 types of human skin cells. These include additional enhancement of ROS production by exposure to physiological levels of UVA. The effects within epidermal and dermal derived skin cells are compared to other tissue cell types as well as those harbouring a compromised mitochondrial status (Rho-zero A549). The results show that the complex II inhibitor, TTFA, was the only RC inhibitor to significantly increase UVA-induced ROS production in both skin cell types (P<0.05) suggesting that the role of human skin complex II in terms of influencing ROS production is more important than previously thought particularly in comparison to liver cells. Interestingly, two-fold greater maximal activity of complex II enzyme was observed in both skin cell types compared to liver (P<0.001). The activities of RC enzymes appear to decrease with increasing age and telomere length is correlated with ageing. Our study showed that the level of maximal complex II activity was higher in the MRC5/hTERT (human lung fibroblasts transfected with telomerase) cells than the corresponding wild type cells (P=0.0012) which can be considered (in terms of telomerase activity) as models of younger and older cells respectively. PMID:25460738

  16. Reactive Oxygen Species-Dependent Nitric Oxide Production Contributes to Hydrogen-Promoted Stomatal Closure in Arabidopsis1[W

    PubMed Central

    Xie, Yanjie; Mao, Yu; Zhang, Wei; Lai, Diwen; Wang, Qingya; Shen, Wenbiao

    2014-01-01

    The signaling role of hydrogen gas (H2) has attracted increasing attention from animals to plants. However, the physiological significance and molecular mechanism of H2 in drought tolerance are still largely unexplored. In this article, we report that abscisic acid (ABA) induced stomatal closure in Arabidopsis (Arabidopsis thaliana) by triggering intracellular signaling events involving H2, reactive oxygen species (ROS), nitric oxide (NO), and the guard cell outward-rectifying K+ channel (GORK). ABA elicited a rapid and sustained H2 release and production in Arabidopsis. Exogenous hydrogen-rich water (HRW) effectively led to an increase of intracellular H2 production, a reduction in the stomatal aperture, and enhanced drought tolerance. Subsequent results revealed that HRW stimulated significant inductions of NO and ROS synthesis associated with stomatal closure in the wild type, which were individually abolished in the nitric reductase mutant nitrate reductase1/2 (nia1/2) or the NADPH oxidase-deficient mutant rbohF (for respiratory burst oxidase homolog). Furthermore, we demonstrate that the HRW-promoted NO generation is dependent on ROS production. The rbohF mutant had impaired NO synthesis and stomatal closure in response to HRW, while these changes were rescued by exogenous application of NO. In addition, both HRW and hydrogen peroxide failed to induce NO production or stomatal closure in the nia1/2 mutant, while HRW-promoted ROS accumulation was not impaired. In the GORK-null mutant, stomatal closure induced by ABA, HRW, NO, or hydrogen peroxide was partially suppressed. Together, these results define a main branch of H2-regulated stomatal movement involved in the ABA signaling cascade in which RbohF-dependent ROS and nitric reductase-associated NO production, and subsequent GORK activation, were causally involved. PMID:24733882

  17. Land, irrigation water, greenhouse gas, and reactive nitrogen burdens of meat, eggs, and dairy production in the United States

    PubMed Central

    Eshel, Gidon; Shepon, Alon; Makov, Tamar; Milo, Ron

    2014-01-01

    Livestock production impacts air and water quality, ocean health, and greenhouse gas (GHG) emissions on regional to global scales and it is the largest use of land globally. Quantifying the environmental impacts of the various livestock categories, mostly arising from feed production, is thus a grand challenge of sustainability science. Here, we quantify land, irrigation water, and reactive nitrogen (Nr) impacts due to feed production, and recast published full life cycle GHG emission estimates, for each of the major animal-based categories in the US diet. Our calculations reveal that the environmental costs per consumed calorie of dairy, poultry, pork, and eggs are mutually comparable (to within a factor of 2), but strikingly lower than the impacts of beef. Beef production requires 28, 11, 5, and 6 times more land, irrigation water, GHG, and Nr, respectively, than the average of the other livestock categories. Preliminary analysis of three staple plant foods shows two- to sixfold lower land, GHG, and Nr requirements than those of the nonbeef animal-derived calories, whereas irrigation requirements are comparable. Our analysis is based on the best data currently available, but follow-up studies are necessary to improve parameter estimates and fill remaining knowledge gaps. Data imperfections notwithstanding, the key conclusion—that beef production demands about 1 order of magnitude more resources than alternative livestock categories—is robust under existing uncertainties. The study thus elucidates the multiple environmental benefits of potential, easy-to-implement dietary changes, and highlights the uniquely high resource demands of beef. PMID:25049416

  18. Rat colonic reactive oxygen species production and DNA damage are mediated by diet and age 

    E-print Network

    Henderson, Cara Aletha Everett

    2001-01-01

    increase with age, and it is possible that ROS and/or DNA damage accumulate in aged animals and lead to carcinogenic mutations. Dietary factors, particularly fat and fiber, are important risk modifiers of colon cancer. Differences in the production of ROS...

  19. Photosensitized Production of Atmospherically Reactive Organic Compounds at the Air/Aqueous Interface

    PubMed Central

    2015-01-01

    We report on experiments that probe photosensitized chemistry at the air/water interface, a region that does not just connect the two phases but displays its own specific chemistry. Here, we follow reactions of octanol, a proxy for environmentally relevant soluble surfactants, initiated by an attack by triplet-state carbonyl compounds, which are themselves concentrated at the interface by the presence of this surfactant. Gas-phase products are determined using PTR-ToF-MS, and those remaining in the organic layer are determined by ATR-FTIR spectroscopy and HPLC-HRMS. We observe the photosensitized production of carboxylic acids as well as unsaturated and branched-chain oxygenated products, compounds that act as organic aerosol precursors and had been thought to be produced solely by biological activity. A mechanism that is consistent with the observations is detailed here, and the energetics of several key reactions are calculated using quantum chemical methods. The results suggest that the concentrating nature of the interface leads to its being a favorable venue for radical reactions yielding complex and functionalized products that themselves could initiate further secondary chemistry and new particle formation in the atmospheric environment. PMID:26068588

  20. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings... Propellor Coatings APC 2.50 Corrosion Resistant Brass, Bronze, or Copper Coatings CRB 1.80 Exact...

  1. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings... APC 2.50 Corrosion Resistant Brass, Bronze, or Copper Coatings CRB 1.80 Exact Match...

  2. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings... Propellor Coatings APC 2.50 Corrosion Resistant Brass, Bronze, or Copper Coatings CRB 1.80 Exact...

  3. 40 CFR Table 1 to Subpart E of... - Product-Weighted Reactivity Limits by Coating Category

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS National Volatile Organic Compound Emission Standards for Aerosol Coatings... APC 2.50 Corrosion Resistant Brass, Bronze, or Copper Coatings CRB 1.80 Exact Match...

  4. ORGANIC MATTER REACTIVITY SURROGATE FOR THE ESTIMATION OF DISINFECTION BY-PRODUCTS FORMATION POTENTIAL

    EPA Science Inventory

    The EPA Office of Ground Water and Drinking Water must have a total organic carbon (TOC) method that can meet the monitoring requirements as originally proposed in the Stage 1, Disinfection By-Products (D/DBP) Rule, as stated in the Federal Register. Research under this task, th...

  5. Relation between cell death progression, reactive oxygen species production and mitochondrial membrane potential in fermenting Saccharomyces cerevisiae cells under heat-shock conditions.

    PubMed

    Pyatrikas, Darya V; Fedoseeva, Irina V; Varakina, Nina N; Rusaleva, Tatyana M; Stepanov, Alexei V; Fedyaeva, Anna V; Borovskii, Gennadii B; Rikhvanov, Eugene G

    2015-06-01

    Moderate heat shock increased reactive oxygen species (ROS) production that led to cell death in glucose-grown Saccharomyces cerevisiae cells. Conditions that disturb mitochondrial functions such as treatment by uncouplers and petite mutation were shown to inhibit ROS production and protects cell from thermal death. Hence, mitochondria are responsible for ROS production and play an active role in cell death. An increase in ROS production was accompanied by hyperpolarization of inner mitochondrial membrane. All agents suppressing hyperpolarization also suppressed heat-induced ROS production. It was supposed that generation of ROS under moderate heat shock in glucose-grown S. cerevisiae cells is driven by the mitochondrial membrane potential. PMID:25991811

  6. PROBING REACTIVITY OF DISSOLVED ORGANIC MATTER FOR DISINFECTION BY-PRODUCT FORMATION USING XAD-8 RESIN ADSORPTION AND ULTRAFILTRATION FRACTIONATION. (R828045)

    EPA Science Inventory

    The disinfection by-product (DBP) reactivity (yield and speciation upon reaction with chlorine) of dissolved organic matter (DOM) isolated from two surface waters was investigated. The source waters, each having significantly different specific ultraviolet absorbance (SUVA

  7. Mitochondrial reactive oxygen species production by fish muscle mitochondria: Potential role in acute heat-induced oxidative stress.

    PubMed

    Banh, Sheena; Wiens, Lilian; Sotiri, Emianka; Treberg, Jason R

    2016-01-01

    Acute heat challenge is known to induce cell-level oxidative stress in fishes. Mitochondria are well known for the capacity to make reactive oxygen species (ROS) and as such are often implicated as a source of the oxidants associated with this thermally-induced oxidative stress. This implication is often asserted, despite little direct data for mitochondrial ROS metabolism in fishes. Here we characterize mitochondrial ROS metabolism in three Actinopterygian fish species at two levels, the capacity for superoxide/H2O2 production and the antioxidant thiol-reductase enzyme activities. We find that red muscle mitochondria from all three species have measurable ROS production and respond to different assay conditions consistent with what might be anticipated; assuming similar relative contributions from difference ROS producing sites as found in rat skeletal muscle mitochondria. Although there are species and assay specific exceptions, fish mitochondria may have a greater capacity to produce ROS than that found in the rat when either normalized to respiratory capacity or determined at a common assay temperature. The interspecific differences in ROS production are not correlated with thiol-based antioxidant reductase activities. Moreover, mimicking an acute in vivo heat stress by comparing the impact of increasing assay temperature on these processes in vitro, we find evidence supporting a preferential activation of mitochondrial H2O2 production relative to the increase in the capacity of reductase enzymes to supply electrons to the mitochondrial matrix peroxidases. This supports the contention that mitochondria may be, at least in part, responsible for the ROS that lead to oxidative stress in fish tissues exposed to acute heat challenge. PMID:26456509

  8. Eicosanoids up-regulate production of reactive oxygen species by NADPH-dependent oxidase in Spodoptera exigua phagocytic hemocytes.

    PubMed

    Park, Youngjin; Stanley, David W; Kim, Yonggyun

    2015-08-01

    Eicosanoids mediate cellular immune responses in insects, including phagocytosis of invading microbes. Phagocytosis entails two major steps, the internalization of microbes and the subsequent killing of them via formation of reactive oxygen species (ROS). Here, we posed the hypothesis that eicosanoids mediate ROS production by activating NADPH-dependent oxidase (NOX) and tested the idea in the model insect, Spodoptera exigua. A NOX gene (we named SeNOX4) was identified and cloned, yielding a full open reading frame encoding 547 amino acid residues with a predicted molecular weight of 63,410Da and an isoelectric point at 9.28. A transmembrane domain and a large intracellular domain containing NADPH and FAD-binding sites were predicted. Phylogenetic analysis indicated SeNOX4 clusters with other NOX4 genes. SeNOX4 was expressed in all life stages except eggs, and exclusively in hemocytes. Bacterial challenge and, separately, arachidonic acid (AA, a precursor of eicosanoid biosynthesis) injection increased its expression. The internalization step was assessed by counting hemocytes engulfing fluorescence-labeled bacteria. The phagocytic behavior was inhibited by dsRNA suppression of SeNOX4 expression and, separately by dexamethasone (DEX, a specific inhibitor of eicosanoid biosynthesis) treatments. However, injecting AA to dsSeNOX4-treated larvae did not rescue the phagocytic activity. Hemocytic ROS production increased following bacterial challenge, which was sharply reduced in dsSeNOX4-treated, and separately, in DEX-treated larvae. AA partially reversed the suppressed ROS production in dsSeNOX4-treated larvae. Treating larvae with either the ROS-suppressing dsSeNOX4 construct or DEX rendered experimental larvae unable to inhibit bacterial proliferation in their hemocoels. We infer that eicosanoids mediate ROS production during phagocytosis by inducing expression of SeNOX4. PMID:26071791

  9. Oxidative phosphorylation efficiency, proton conductance and reactive oxygen species production of liver mitochondria correlates with body mass in frogs.

    PubMed

    Roussel, Damien; Salin, Karine; Dumet, Adeline; Romestaing, Caroline; Rey, Benjamin; Voituron, Yann

    2015-10-01

    Body size is a central biological parameter affecting most biological processes (especially energetics) and the mitochondrion is a key organelle controlling metabolism and is also the cell's main source of chemical energy. However, the link between body size and mitochondrial function is still unclear, especially in ectotherms. In this study, we investigated several parameters of mitochondrial bioenergetics in the liver of three closely related species of frog (the common frog Rana temporaria, the marsh frog Pelophylax ridibundus and the bull frog Lithobates catesbeiana). These particular species were chosen because of their differences in adult body mass. We found that mitochondrial coupling efficiency was markedly increased with animal size, which led to a higher ATP production (+70%) in the larger frogs (L. catesbeiana) compared with the smaller frogs (R. temporaria). This was essentially driven by a strong negative dependence of mitochondrial proton conductance on body mass. Liver mitochondria from the larger frogs (L. catesbeiana) displayed 50% of the proton conductance of mitochondria from the smaller frogs (R. temporaria). Contrary to our prediction, the low mitochondrial proton conductance measured in L. catesbeiana was not associated with higher reactive oxygen species production. Instead, liver mitochondria from the larger individuals produced significantly lower levels of radical oxygen species than those from the smaller frogs. Collectively, the data show that key bioenergetics parameters of mitochondria (proton leak, ATP production efficiency and radical oxygen species production) are correlated with body mass in frogs. This research expands our understanding of the relationship between mitochondrial function and the evolution of allometric scaling in ectotherms. PMID:26347565

  10. Spatial Coordination of Aluminum Uptake, Production of Reactive Oxygen Species, Callose Production and Wall Rigidification in Maize Roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum toxicity associated with acid soils represents one of the biggest limitations to crop production worldwide. Although Al specifically inhibits the elongation of root cells, the exact mechanism by which this growth reduction occurs remains controversial. The aim of this study was to investiga...

  11. Multijet production at low x in deep inelastic scattering at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Nuncio-Quiroz, A. E.; Paul, E.; Renner, R.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Namsoo, T.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Blohm, C.; Bonato, A.; Borras, K.; Ciesielski, R.; Coppola, N.; Dossanov, A.; Drugakov, V.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Hüttmann, A.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Notz, D.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Ferrando, J.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Korcsak-Gorzo, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.; ZEUS Collaboration

    2007-12-01

    Inclusive dijet and trijet production in deep inelastic ep scattering has been measured for 10

  12. Measurement of D ± production in deep inelastic ep scattering with the ZEUS detector at HERA

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Antonelli, S.; Antonioli, P.; Antonov, A.; Arneodo, M.; Arslan, O.; Aushev, V.; Aushev, Y.; Bachynska, O.; Bamberger, A.; Barakbaev, A. N.; Barbagli, G.; Bari, G.; Barreiro, F.; Bartosik, N.; Bartsch, D.; Basile, M.; Behnke, O.; Behr, J.; Behrens, U.; Bellagamba, L.; Bertolin, A.; Bhadra, S.; Bindi, M.; Blohm, C.; Bokhonov, V.; Bold, T.; Boos, E. G.; Borras, K.; Boscherini, D.; Bot, D.; Brock, I.; Brownson, E.; Brugnera, R.; Brümmer, N.; Bruni, A.; Bruni, G.; Brzozowska, B.; Bussey, P. J.; Bylsma, B.; Caldwell, A.; Capua, M.; Carlin, R.; Catterall, C. D.; Chekanov, S.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; Cooper-Sarkar, A. M.; Coppola, N.; Corradi, M.; Corriveau, F.; Costa, M.; D'Agostini, G.; Corso, F. Dal; del Peso, J.; Dementiev, R. K.; De Pasquale, S.; Derrick, M.; Devenish, R. C. E.; Dobur, D.; Dolgoshein, B. A.; Dolinska, G.; Doyle, A. T.; Drugakov, V.; Durkin, L. S.; Dusini, S.; Eisenberg, Y.; Ermolov, P. F.; Eskreys, A.; Fang, S.; Fazio, S.; Ferrando, J.; Ferrero, M. I.; Figiel, J.; Foster, B.; Gach, G.; Galas, A.; Gallo, E.; Garfagnini, A.; Geiser, A.; Gialas, I.; Gizhko, A.; Gladilin, L. K.; Gladkov, D.; Glasman, C.; Gogota, O.; Golubkov, Yu. A.; Göttlicher, P.; Grabowska-Bold, I.; Grebenyuk, J.; Gregor, I.; Grigorescu, G.; Grzelak, G.; Gueta, O.; Guzik, M.; Gwenlan, C.; Haas, T.; Hain, W.; Hamatsu, R.; Hart, J. C.; Hartmann, H.; Hartner, G.; Hilger, E.; Hochman, D.; Hori, R.; Hüttmann, A.; Ibrahim, Z. A.; Iga, Y.; Ingbir, R.; Ishitsuka, M.; Iudin, A.; Jakob, H.-P.; Januschek, F.; Jones, T. W.; Jüngst, M.; Kadenko, I.; Kahle, B.; Kananov, S.; Kanno, T.; Karshon, U.; Karstens, F.; Katkov, I. I.; Kaur, M.; Kaur, P.; Keramidas, A.; Khein, L. A.; Kim, J. Y.; Kisielewska, D.; Kitamura, S.; Klanner, R.; Klein, U.; Koffeman, E.; Kondrashova, N.; Kononenko, O.; Kooijman, P.; Korol, Ie.; Korzhavina, I. A.; Kotanski, A.; Kötz, U.; Kovalchuk, N.; Kowalski, H.; Kuprash, O.; Kuze, M.; Lee, A.; Levchenko, B. B.; Levy, A.; Libov, V.; Limentani, S.; Ling, T. Y.; Lisovyi, M.; Lobodzinska, E.; Lohmann, W.; Löhr, B.; Lohrmann, E.; Long, K. R.; Longhin, A.; Lontkovskyi, D.; Lukina, O. Yu.; Maeda, J.; Magill, S.; Makarenko, I.; Malka, J.; Mankel, R.; Margotti, A.; Marini, G.; Martin, J. F.; Mastroberardino, A.; Mattingly, M. C. K.; Melzer-Pellmann, I.-A.; Mergelmeyer, S.; Miglioranzi, S.; Idris, F. Mohamad; Monaco, V.; Montanari, A.; Morris, J. D.; Mujkic, K.; Musgrave, B.; Nagano, K.; Namsoo, T.; Nania, R.; Nigro, A.; Ning, Y.; Nobe, T.; Notz, D.; Nowak, R. J.; Nuncio-Quiroz, A. E.; Oh, B. Y.; Okazaki, N.; Olkiewicz, K.; Onishchuk, Yu.; Papageorgiu, K.; Parenti, A.; Paul, E.; Pawlak, J. M.; Pawlik, B.; Pelfer, P. G.; Pellegrino, A.; Perlanski, W.; Perrey, H.; Piotrzkowski, K.; Plucinski, P.; Pokrovskiy, N. S.; Polini, A.; Proskuryakov, A. S.; Przybycien, M.; Raval, A.; Reeder, D. D.; Reisert, B.; Ren, Z.; Repond, J.; Ri, Y. D.; Robertson, A.; Roloff, P.; Rubinsky, I.; Ruspa, M.; Sacchi, R.; Samson, U.; Sartorelli, G.; Savin, A. A.; Saxon, D. H.; Schioppa, M.; Schlenstedt, S.; Schleper, P.; Schmidke, W. B.; Schneekloth, U.; Schönberg, V.; Schörner-Sadenius, T.; Schwartz, J.; Sciulli, F.; Shcheglova, L. M.; Shehzadi, R.; Shimizu, S.; Singh, I.; Skillicorn, I. O.; Slominski, W.; Smith, W. H.; Sola, V.; Solano, A.; Son, D.; Sosnovtsev, V.; Spiridonov, A.; Stadie, H.; Stanco, L.; Stefaniuk, N.; Stern, A.; Stewart, T. P.; Stifutkin, A.; Stopa, P.; Suchkov, S.; Susinno, G.; Suszycki, L.; Sztuk-Dambietz, J.; Szuba, D.; Szuba, J.; Tapper, A. D.; Tassi, E.; Terrón, J.; Theedt, T.; Tiecke, H.; Tokushuku, K.; Tomaszewska, J.; Trofymov, A.; Trusov, V.; Tsurugai, T.; Turcato, M.; Turkot, O.; Tymieniecka, T.; Vázquez, M.; Verbytskyi, A.; Viazlo, O.; Vlasov, N. N.; Walczak, R.; Abdullah, W. A. T. Wan; Whitmore, J. J.; Wichmann, K.; Wiggers, L.; Wing, M.; Wlasenko, M.; Wolf, G.; Wolfe, H.; Wrona, K.; Yagües-Molina, A. G.; Yamada, S.; Yamazaki, Y.; Yoshida, R.; Youngman, C.; Zakharchuk, N.; ?arnecki, A. F.; Zawiejski, L.; Zenaiev, O.; Zeuner, W.; Zhautykov, B. O.; Zhmak, N.; Zichichi, A.; Zolkapli, Z.; Zotkin, D. S.

    2013-05-01

    Charm production in deep inelastic ep scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb-1. Charm quarks were identified by reconstructing D ± mesons in the D ± ? K ??±?± decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5 < Q 2 < 1000 GeV2, 0 .02 < y < 0 .7, 1 .5 < p T ( D ±) < 15 GeV and | ?( D ±)| < 1 .6, where Q 2 is the photon virtuality, y is the inelasticity, and p T ( D ±) and ?( D ±) are the transverse momentum and the pseudorapidity of the D ± meson, respectively. Next-to-leading-order QCD predictions are compared to the data. The charm contribution, F_2^{{coverline{c}}} , to the proton structure-function F 2 was extracted.

  13. Mechanism of pion production in {alpha}p scattering at 1 GeV/nucleon

    SciTech Connect

    Alkhazov, G. D.; Prokofiev, A. N. Smirnov, I. B.; Strokovsky, E. A.

    2012-09-15

    An analysis of the experimental data on one-pion and two-pion production in the p({alpha}, {alpha} Prime )X reaction studied in a semi-exclusive experiment at an energy of E{sub {alpha}} = 4.2 GeV has been performed. The obtained results demonstrate that the inelastic {alpha}-particle scattering on the proton at the energy of the experiment proceeds either through excitation and decay of the {Delta} resonance in the projectile {alpha} particle, or through excitation in the target proton of the Roper resonance, which decays into a nucleon and a pion, or a nucleon and a {sigma} meson-a system of two pions in the isospin I = 0, S-wave state.

  14. Effects of nitrogen dioxide and its acid mist on reactive oxygen species production and antioxidant enzyme activity in Arabidopsis plants.

    PubMed

    Liu, Xiaofang; Hou, Fen; Li, Guangke; Sang, Nan

    2015-08-01

    Nitrogen dioxide (NO2) is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species (ROS) production and antioxidant enzyme activity in Arabidopsis thaliana (Col-0) exposed to 1.7, 4, 8.5, and 18.8mg/m(3) NO2. The results indicate that NO2 exposure affected plant growth and chlorophyll (Chl) content, and increased oxygen free radical (O2(-)) production rate in Arabidopsis shoots. Furthermore, NO2 elevated the levels of lipid peroxidation and protein oxidation, accompanied by the induction of antioxidant enzyme activities and change of ascorbate (AsA) and glutathione (GSH) contents. Following this, we mimicked nitric acid mist under experimental conditions, and confirmed the antioxidant mechanism of the plant to the stress. Our results imply that NO2 and its acid mist caused pollution risk to plant systems. During the process, increased ROS acted as a signal to induce a defense response, and antioxidant status played an important role in plant protection against NO2/nitric acid mist-caused oxidative damage. PMID:26257351

  15. Structural Evolution of Iron Antimonides from Amorphous Precursors to Crystalline Products Studied by Total Scattering Techniques.

    PubMed

    Bauers, Sage R; Wood, Suzannah R; Jensen, Kirsten M Ø; Blichfeld, Anders B; Iversen, Bo B; Billinge, Simon J L; Johnson, David C

    2015-08-01

    Homogeneous reaction precursors may be used to form several solid-state compounds inaccessible by traditional synthetic routes, but there has been little development of techniques that allow for a priori prediction of what may crystallize in a given material system. Here, the local structures of FeSbx designed precursors are determined and compared with the structural motifs of their crystalline products. X-ray total scattering and atomic pair distribution function (PDF) analysis are used to show that precursors that first nucleate a metastable FeSb3 compound share similar local structure to the product. Interestingly, precursors that directly crystallize to thermodynamically stable FeSb2 products also contain local structural motifs of the metastable phase, despite their compositional disagreement. While both crystalline phases consist of distorted FeSb6 octahedra with Sb shared between either two or three octahedra as required for stoichiometry, a corner-sharing arrangement indicative of AX3-type structures is the only motif apparent in the PDF of either precursor. Prior speculation was that local composition controlled which compounds nucleate from amorphous intermediates, with different compositions favoring different local arrangements and hence different products. This data suggests that local environments in these amorphous intermediates may not be very sensitive to overall composition. This can provide insight into potential metastable phases which may form in a material system, even with a precursor that does not crystallize to the kinetically stabilized product. Determination of local structure in homogeneous amorphous reaction intermediates from techniques such as PDF can be a valuable asset in the development of systematic methods to prepare targeted solid-state compounds from designed precursors. PMID:26161946

  16. Hypothesis on Skeletal Muscle Aging: Mitochondrial Adenine Nucleotide Translocator Decreases Reactive Oxygen Species Production While Preserving Coupling Efficiency

    PubMed Central

    Diolez, Philippe; Bourdel-Marchasson, Isabelle; Calmettes, Guillaume; Pasdois, Philippe; Detaille, Dominique; Rouland, Richard; Gouspillou, Gilles

    2015-01-01

    Mitochondrial membrane potential is the major regulator of mitochondrial functions, including coupling efficiency and production of reactive oxygen species (ROS). Both functions are crucial for cell bioenergetics. We previously presented evidences for a specific modulation of adenine nucleotide translocase (ANT) appearing during aging that results in a decrease in membrane potential - and therefore ROS production—but surprisingly increases coupling efficiency under conditions of low ATP turnover. Careful study of the bioenergetic parameters (oxidation and phosphorylation rates, membrane potential) of isolated mitochondria from skeletal muscles (gastrocnemius) of aged and young rats revealed a remodeling at the level of the phosphorylation system, in the absence of alteration of the inner mitochondrial membrane (uncoupling) or respiratory chain complexes regulation. We further observed a decrease in mitochondrial affinity for ADP in aged isolated mitochondria, and higher sensitivity of ANT to its specific inhibitor atractyloside. This age-induced modification of ANT results in an increase in the ADP concentration required to sustain the same ATP turnover as compared to young muscle, and therefore in a lower membrane potential under phosphorylating—in vivo—conditions. Thus, for equivalent ATP turnover (cellular ATP demand), coupling efficiency is even higher in aged muscle mitochondria, due to the down-regulation of inner membrane proton leak caused by the decrease in membrane potential. In the framework of the radical theory of aging, these modifications in ANT function may be the result of oxidative damage caused by intra mitochondrial ROS and may appear like a virtuous circle where ROS induce a mechanism that reduces their production, without causing uncoupling, and even leading in improved efficiency. Because of the importance of ROS as therapeutic targets, this new mechanism deserves further studies. PMID:26733871

  17. Promotion of ?-amyloid production by C-reactive protein and its implications in the early pathogenesis of Alzheimer's disease.

    PubMed

    Bi, Bing-Tian; Lin, Huan-Bing; Cheng, Yu-Fang; Zhou, Heng; Lin, Ting; Zhang, Ming-Zi; Li, Tie-Jun; Xu, Jiang-Ping

    2012-02-01

    C-reactive protein (CRP) and ?-amyloid protein (A?) are involved in the development of Alzheimer's disease (AD). However, the relationship between CRP and A? production is unclear. In vitro and in vivo experiments were performed to investigate the association of CRP with A? production. Using the rat adrenal pheochromocytoma cell line (PC12 cells) to mimic neurons, cytotoxicity was evaluated by cell viability and supernatant lactate dehydrogenase (LDH) activity. The levels of amyloid precursor protein (APP), beta-site APP cleaving enzyme (BACE-1), and presenilins (PS-1 and PS-2) were investigated using real-time polymerase chain reaction and Western blotting analysis. A?1-42 was measured by enzyme-linked immunosorbent assay. The relevance of CRP and A? as well as potential mechanisms were studied using APP/PS1 transgenic (Tg) mice. Treatment with 0.5-4.0 ?M CRP for 48 h decreased cell viability and increased LDH leakage in PC12 cells. Incubation with CRP at a sub-toxic concentration of 0.2 ?M increased the mRNA levels of APP, BACE-1, PS-1, and PS-2, as well as A?1-42 production. CRP inhibitor reversed the CRP-induced upregulations of the mRNA levels of APP, BACE-1, PS-1, and PS-2, and the protein levels of APP, BACE-1, PS-1, and A?1-42, but did not reversed A?1-42 cytotoxicity. The cerebral levels of CRP and A?1-42 in APP/PS1 Tg mice were positively correlated, accompanied with the elevated mRNA expressions of serum amyloid P component (SAP), complement component 1q (C1q), and tumor necrosis factor-? (TNF-?). These results suggest that CRP cytotoxicity is associated with A? formation and A?-related markers expressions; CRP and A? were relevant in early-stage AD; CRP may be an important trigger in AD pathogenesis. PMID:22202667

  18. Isochoric Burn, an Internally Consistent Method for the Reactant to Product Transformation in Reactive Flow

    SciTech Connect

    Reaugh, J E; Lee, E L

    2002-07-01

    Mixture rules for partially reacted explosives differ amongst various models. For instance, JWL++ uses a partial pressure addition to compute an average zonal pressure, Ignition and Growth requires pressure equilibration and thermal equilibration of temperature dependent JWL EOSs, CHEETAH In Line RF also assumes temperature and pressure equilibration. It has been suggested in the past that a more realistic equilibration scheme should comprise isentropic pressure equilibration of the separate reacted and unreacted phases. This turns out not to be a proper path for equilibration. Rather, we find that the only internally consistent method is the evaluation of the equilibrium pressure that satisfies the particular conditions of reactant and product resulting from deflagration in a fixed volume.

  19. Reactive scattering calculations for (87)Rb+(87)RbHe?Rb2((3)?(u)(+),v)+He from ultralow to intermediate energies.

    PubMed

    Rodríguez-Cantano, Rocío; González-Lezana, Tomás; Prosmiti, Rita; Delgado-Barrio, Gerardo; Villarreal, Pablo; Jellinek, Julius

    2015-04-28

    We investigate atom-diatom reactive collisions, as a preliminary step,in order to assess the possibility of forming Rb(2) molecules in their lowest triplet electronic state by cold collisions of rubidium atoms on the surface of helium nanodroplets [corrected]. A simple model related to the well-known Rosen treatment of linear triatomic molecules [N. Rosen, J. Chem. Phys. 1, 319 (1933)] in relative coordinates is used, allowing to estimate reactive probabilities for different values of the total angular momentum. The best available full dimensional potential energy surface [Guillon et al., J. Chem. Phys. 136, 174307 (2012)] is employed through the calculations. Noticeable values of the probabilities in the ultracold regime, which numerically fulfill the Wigner threshold law, support the feasibility of the process. The rubidium dimer is mainly produced at high vibrational states, and the reactivity is more efficient for a bosonic helium partner than when the fermion species is considered. PMID:25933761

  20. Momentum space saturation model for deep inelastic scattering and single inclusive hadron production

    NASA Astrophysics Data System (ADS)

    Basso, E. A. F.; Gay Ducati, M. B.; de Oliveira, E. G.

    2011-08-01

    We show how the Santana Amaral-Gay Ducati-Betemps-Soyez (AGBS) model, originally developed for deep inelastic scattering applied to HERA data on the proton structure function, can also describe the RHIC data on single inclusive hadron yield for d+Au and p+p collisions through a new simultaneous fit. The single inclusive hadron production is modeled through the color glass condensate, which uses the quark (and gluon) condensate amplitudes in momentum space. The AGBS model is also a momentum space model based on the asymptotic solutions of the Balitsky-Kovchegov equation, although a different definition of the Fourier transform is used. This aspect is overcome, and a description entirely in transverse momentum of both processes arises for the first time. The small difference between the simultaneous fit and the one for HERA data alone suggests that the AGBS model describes very well both kinds of processes and thus emerges as a good tool to investigate the inclusive hadron production data. We use this model for predictions at LHC energies, which agrees very well with available experimental data.

  1. Autophagy inhibition enhances silibinin-induced apoptosis by regulating reactive oxygen species production in human prostate cancer PC-3 cells.

    PubMed

    Kim, Sang-Hun; Kim, Kwang-Youn; Yu, Sun-Nyoung; Park, Seul-Ki; Choi, Hyeun-Deok; Ji, Jae-Hoon; Ahn, Soon-Cheol

    2015-12-01

    Silibinin is a major bioactive component of silymarin and has anticancer effects on cancer cell line and has been used as a supportive therapy for chronic inflammatory liver condition. These anticancer effects of silibinin have been demonstrated both in vitro and in vivo cancer models. Although various evidences showed apoptosis signaling pathways by silibinin, there is no report to address the clearly mechanism of silibinin-induced autophagy in prostate cancer PC-3 cells. Our study showed that silibinin triggered autophagy through up-regulation of microtubule-associated protein 1 light chain 3 (LC3)-II, formation of acidic vesicular organelles (AVO) and punctuate of GFP-LC3, which was inhibited by 3-methyladenine (3-MA), an inhibitor of specific autophagy. In addition, silibinin induced autophagy through production of reactive oxygen species (ROS). Inhibition of ROS with diphenyleneiodonium (DPI), a ROS inhibitor, attenuated silibinin-triggered autophagy. Inhibition of autophagy with 3-MA enhanced the silibinin-induced apoptosis through the regulation of caspase-3 and PARP. These results suggested that silibinin induced autophagy by regulating ROS and its mechanism played a protective role against apoptosis in PC-3 cells. PMID:26522224

  2. Production of hybrid diesel fuel precursors from carbohydrates and petrochemicals using formic acid as a reactive solvent.

    PubMed

    Zhou, Xiaoyuan; Rauchfuss, Thomas B

    2013-02-01

    We report the one-pot alkylation of mesitylene with carbohydrate-derived 5-(hydroxymethyl)furfural (HMF) as a step toward diesel-range liquids. Using FeCl(3) as a catalyst, HMF is shown to alkylate toluene, xylene, and mesitylene in high yields in CH(2)Cl(2) and MeNO(2) solvents. Efforts to extend this reaction to greener or safer solvents showed that most ether-based solvents are unsatisfactory. Acid catalysts (e.g, p-TsOH) also proved to be ineffective. Using formic acid as a reactive solvent, mesitylene could be alkylated to give mesitylmethylfurfural (MMF) starting from fructose with yields up to approximately 70 %. The reaction of fructose with formic acid in the absence of mesitylene gave rise to low yields of the formate ester of HMF, which indicates the stabilizing effect of replacing the hydroxyl substituent with mesityl. The arene also serves as a second phase into which the product is extracted. Even by using formic acid, the mesitylation of less expensive precursors such as glucose and cellulose proceeded only in modest yields (ca. 20 %). These simpler substrates were found to undergo mesitylation by using hydrogen chloride/formic acid via the intermediate chloromethylfurfural. PMID:23281330

  3. Anethole induces apoptotic cell death accompanied by reactive oxygen species production and DNA fragmentation in Aspergillus fumigatus and Saccharomyces cerevisiae.

    PubMed

    Fujita, Ken-Ichi; Tatsumi, Miki; Ogita, Akira; Kubo, Isao; Tanaka, Toshio

    2014-02-01

    trans-Anethole (anethole), a major component of anise oil, has a broad antimicrobial spectrum, and antimicrobial activity that is weaker than that of other antibiotics on the market. When combined with polygodial, nagilactone E, and n-dodecanol, anethole has been shown to possess significant synergistic antifungal activity against a budding yeast, Saccharomyces cerevisiae, and a human opportunistic pathogenic yeast, Candida albicans. However, the antifungal mechanism of anethole has not been completely determined. We found that anethole stimulated cell death of a human opportunistic pathogenic fungus, Aspergillus fumigatus, in addition to S. cerevisiae. The anethole-induced cell death was accompanied by reactive oxygen species production, metacaspase activation, and DNA fragmentation. Several mutants of S. cerevisiae, in which genes related to the apoptosis-initiating execution signals from mitochondria were deleted, were resistant to anethole. These results suggest that anethole-induced cell death could be explained by oxidative stress-dependent apoptosis via typical mitochondrial death cascades in fungi, including A. fumigatus and S. cerevisiae. PMID:24393541

  4. Ultracold neutron production and up-scattering in superfluid helium between 1.1 K and 2.4 K

    E-print Network

    K. K. H. Leung; S. Ivanov; F. M. Piegsa; M. Simson; O. Zimmer

    2015-07-27

    Ultracold neutrons (UCNs) were produced in a 4 liter volume of superfluid helium using the PF1B cold neutron beam facility at the Institut Laue-Langevin and then extracted to a detector at room temperature. With a converter temperature of 1.08 K the number of accumulated UCNs was counted to be $91,\\!700 \\pm 300$. From this, we derive a volumetric UCN production rate of $(6.9 \\pm 1.7)\\,\\mathrm{cm^{-3}\\,s^{-1}}$, which includes a correction for losses in the converter during UCN extraction caused by a short storage time, but not accounting for UCN transport and detection efficiencies. The up-scattering rate of UCNs due to excitations in the superfluid was studied by scanning the temperature between 1.2-2.4 K. Using the temperature-dependent UCN production rate calculated from inelastic neutron scattering data in the analysis, the only UCN up-scattering process found to be present was from two-phonon scattering. Our analysis rules out contributions from the other scattering processes to $\\lesssim 10\\%$ of their predicted levels.

  5. Chlamydia muridarum infection of macrophages elicits bactericidal nitric oxide production via reactive oxygen species and cathepsin B.

    PubMed

    Rajaram, Krithika; Nelson, David E

    2015-08-01

    The ability of certain species of Chlamydia to inhibit the biogenesis of phagolysosomes permits their survival and replication within macrophages. The survival of macrophage-adapted chlamydiae correlates with the multiplicity of infection (MOI), and optimal chlamydial growth occurs in macrophages infected at an MOI of ?1. In this study, we examined the replicative capacity of Chlamydia muridarum in the RAW 264.7 murine macrophage cell line at different MOIs. C. muridarum productively infected these macrophages at low MOIs but yielded few viable elementary bodies (EBs) when macrophages were infected at a moderate (10) or high (100) MOI. While high MOIs caused cytotoxicity and irreversible host cell death, macrophages infected at a moderate MOI did not show signs of cytotoxicity until late in the infectious cycle. Inhibition of host protein synthesis rescued C. muridarum in macrophages infected at a moderate MOI, implying that chlamydial growth was blocked by activated defense mechanisms. Conditioned medium from these macrophages was antichlamydial and contained elevated levels of interleukin 1? (IL-1?), IL-6, IL-10, and beta interferon (IFN-?). Macrophage activation depended on Toll-like receptor 2 (TLR2) signaling, and cytokine production required live, transcriptionally active chlamydiae. A hydroxyl radical scavenger and inhibitors of inducible nitric oxide synthase (iNOS) and cathepsin B also reversed chlamydial killing. High levels of reactive oxygen species (ROS) led to an increase in cathepsin B activity, and pharmacological inhibition of ROS and cathepsin B reduced iNOS expression. Our data demonstrate that MOI-dependent TLR2 activation of macrophages results in iNOS induction via a novel ROS- and cathepsin-dependent mechanism to facilitate C. muridarum clearance. PMID:26015483

  6. Spatio-temporal relief from hypoxia and production of reactive oxygen species during bud burst in grapevine (Vitis vinifera)

    PubMed Central

    Meitha, Karlia; Konnerup, Dennis; Colmer, Timothy D.; Considine, John A.; Foyer, Christine H.; Considine, Michael J.

    2015-01-01

    Background and Aims Plants regulate cellular oxygen partial pressures (pO2), together with reduction/oxidation (redox) state in order to manage rapid developmental transitions such as bud burst after a period of quiescence. However, our understanding of pO2 regulation in complex meristematic organs such as buds is incomplete and, in particular, lacks spatial resolution. Methods The gradients in pO2 from the outer scales to the primary meristem complex were measured in grapevine (Vitis vinifera) buds, together with respiratory CO2 production rates and the accumulation of superoxide and hydrogen peroxide, from ecodormancy through the first 72?h preceding bud burst, triggered by the transition from low to ambient temperatures. Key Results Steep internal pO2 gradients were measured in dormant buds with values as low as 2·5?kPa found in the core of the bud prior to bud burst. Respiratory CO2 production rates increased soon after the transition from low to ambient temperatures and the bud tissues gradually became oxygenated in a patterned process. Within 3?h of the transition to ambient temperatures, superoxide accumulation was observed in the cambial meristem, co-localizing with lignified cellulose associated with pro-vascular tissues. Thereafter, superoxide accumulated in other areas subtending the apical meristem complex, in the absence of significant hydrogen peroxide accumulation, except in the cambial meristem. By 72?h, the internal pO2 gradient showed a biphasic profile, where the minimum pO2 was external to the core of the bud complex. Conclusions Spatial and temporal control of the tissue oxygen environment occurs within quiescent buds, and the transition from quiescence to bud burst is accompanied by a regulated relaxation of the hypoxic state and accumulation of reactive oxygen species within the developing cambium and vascular tissues of the heterotrophic grapevine buds. PMID:26337519

  7. MuRF1 activity is present in cardiac mitochondria and regulates reactive oxygen species production in vivo

    PubMed Central

    Mattox, Taylor A.; Young, Martin E.; Rubel, Carrie E.; Spaniel, Carolyn; Rodríguez, Jessica E.; Grevengoed, Trisha J.; Gautel, Mathias; Xu, Zhelong; Anderson, Ethan J.; Willis, Monte S.

    2014-01-01

    MuRF1 is a previously reported ubiquitin-ligase found in striated muscle that targets troponin I and myosin heavy chain for degradation. While MuRF1 has been reported to interact with mitochondrial substrates in yeast two-hybrid studies, no studies have identified MuRF1’s role in regulating mitochondrial function to date. In the present study, we measured cardiac mitochondrial function from isolated permeabilized muscle fibers in previously phenotyped MuRF1 transgenic and MuRF1?/? mouse models to determine the role of MuRF1 in intermediate energy metabolism and ROS production. We identified a significant decrease in reactive oxygen species production in cardiac muscle fibers from MuRF1 transgenic mice with increased alpha-MHC driven MuRF1 expression. Increased MuRF1 expression in ex vivo and in vitro experiments revealed no alterations in the respiratory chain complex I and II function. Working perfusion experiments on MuRF1 transgenic hearts demonstrated significant changes in glucose or oleate oxidation; however, total oxygen consumption was decreased. This data provides evidence for MuRF1 as a novel regulator of cardiac ROS, offering another mechanism by which increased MuRF1 expression may be cardioprotective in ischemia reperfusion injury, in addition to its inhibition of apoptosis via proteasome-mediate degradation of c-Jun. The lack of mitochondrial function phenotype identified in MuRF1?/? hearts may be due to the overlapping interactions of MuRF1 and MuRF2 with energy regulating proteins found by yeast two-hybrid studies reported here, implying a duplicity in MuRF1 and MuRF2’s regulation of mitochondrial function. PMID:24733503

  8. A process for enhancing the accessibility and reactivity of hardwood kraft-based dissolving pulp for viscose rayon production by cellulase treatment.

    PubMed

    Miao, Qingxian; Chen, Lihui; Huang, Liulian; Tian, Chao; Zheng, Linqiang; Ni, Yonghao

    2014-02-01

    The commercial pre-hydrolysis kraft-based dissolving pulp production process can be a typical example for the demonstration/implementation of the integrated forest biorefinery concept. In this study, the concept of cellulase treatment of this dissolving pulp for enhancement of accessibility/reactivity in terms of viscose rayon production was demonstrated. The cellulase treatment resulted in the formation of additional openings/surface areas in the fiber structure via the possible action of "etching". As a result, the pore volume of pulp fibers increased, which led to the increase in the accessibility to xanthation, and thus Fock reactivity. Results showed that the cellulase treatment was effective in increasing the Fock reactivity, at a cellulase dosage of 2u/g (based on the dry weight of pulp), the Fock reactivity increased from 47.67% to 79.9%. The adoption of cellulase treatment to hardwood kraft-based dissolving pulp can provide an efficient approach for enhancing its performance in the commercial viscose-rayon process. PMID:24384317

  9. J/?-pair production at large momenta: Indications for double parton scatterings and large ?s5 contributions

    NASA Astrophysics Data System (ADS)

    Lansberg, Jean-Philippe; Shao, Hua-Sheng

    2015-12-01

    We demonstrate that the recent studies of J / ?-pair production by CMS at the LHC and by D0 at the Tevatron reveal the presence of different production mechanisms in different kinematical regions. We find out that next-to-leading-order single parton scattering contributions at ?s5 dominate the yield at large transverse momenta of the pair. Our analysis further emphasises the importance of double parton scatterings - which are expected to dominate the yield at large J / ?-rapidity differences - at large invariant masses of the pair in the CMS acceptance, and thereby solve a large discrepancy between the theory and the CMS data. In addition, we provide the first exact - gauge-invariant and infrared-safe - evaluation of a class of leading-PT (PT-4) next-to-next-to-leading-order contributions at ?s6, which can be relevant in the region of large values of PTmin = min ? (PT1, PT2). Finally, we derive simple relations for the feed-down fractions from the production of an excited charmonium state with a J / ? in the case of the dominance of the double parton scatterings, which significantly deviate from those for single parton scatterings. Such relations can be used to discriminate these extreme scenarios, either DPS or SPS dominance.

  10. Three-dimensional Monte-Carlo simulation of gamma-ray scattering and production in the atmosphere

    SciTech Connect

    Morris, D.J. )

    1989-05-15

    Monte Carlo codes have been developed to simulate gamma-ray scattering and production in the atmosphere. The scattering code simulates interactions of low-energy gamma rays (20 to several hundred keV) from an astronomical point source in the atmosphere; a modified code also simulates scattering in a spacecraft. Four incident spectra, typical of gamma-ray bursts, solar flares, and the Crab pulsar, and 511 keV line radiation have been studied. These simulations are consistent with observations of solar flare radiation scattered from the atmosphere. The production code simulates the interactions of cosmic rays which produce high-energy (above 10 MeV) photons and electrons. It has been used to calculate gamma-ray and electron albedo intensities at Palestine, Texas and at the equator; the results agree with observations in most respects. With minor modifications this code can be used to calculate intensities of other high-energy particles. Both codes are fully three-dimensional, incorporating a curved atmosphere; the production code also incorporates the variation with both zenith and azimuth of the incident cosmic-ray intensity due to geomagnetic effects. These effects are clearly reflected in the calculated albedo by intensity contrasts between the horizon and nadir, and between the east and west horizons.

  11. Fracture Reactivation in Chemically Reactive Rock Systems

    NASA Astrophysics Data System (ADS)

    Eichhubl, P.; Hooker, J. N.

    2013-12-01

    Reactivation of existing fractures is a fundamental process of brittle failure that controls the nucleation of earthquake ruptures, propagation and linkage of hydraulic fractures in oil and gas production, and the evolution of fault and fracture networks and thus of fluid and heat transport in the upper crust. At depths below 2-3 km, and frequently shallower, brittle processes of fracture growth, linkage, and reactivation compete with chemical processes of fracture sealing by mineral precipitation, with precipitation rates similar to fracture opening rates. We recently found rates of fracture opening in tectonically quiescent settings of 10-20 ?m/m.y., rates similar to euhedral quartz precipitation under these conditions. The tendency of existing partially or completely cemented fractures to reactivate will vary depending on strain rate, mineral precipitation kinetics, strength contrast between host rock and fracture cement, stress conditions, degree of fracture infill, and fracture network geometry. Natural fractures in quartzite of the Cambrian Eriboll Formation, NW Scotland, exhibit a complex history of fracture formation and reactivation, with reactivation involving both repeated crack-seal opening-mode failure and shear failure of fractures that formed in opening mode. Fractures are partially to completely sealed with crack-seal or euhedral quartz cement or quartz cement fragmented by shear reactivation. Degree of cementation controls the tendency of fractures for later shear reactivation, to interact elastically with adjacent open fractures, and their intersection behavior. Using kinematic, dynamic, and diagenetic criteria, we determine the sequence of opening-mode fracture formation and later shear reactivation. We find that sheared fracture systems of similar orientation display spatially varying sense of slip We attribute these inconsistent directions of shear reactivation to 1) a heterogeneous stress field in this highly fractured rock unit and 2) variations in the degree of fracture cement infill in fractures of same orientation, allowing fractures to reactivate at times when adjacent, more cemented fractures remain dormant. The observed interaction of chemical and mechanical fracture growth and sealing processes in this chemically reactive and heavily deformed rock unit results in a complex fracture network geometry not generally observed in less chemically reactive, shallower crustal environments.

  12. Production of exclusive dijets in diffractive deep inelastic scattering at HERA

    E-print Network

    ZEUS Collaboration; H. Abramowicz; I. Abt; L. Adamczyk; M. Adamus; S. Antonelli; V. Aushev; Y. Aushev; O. Behnke; U. Behrens; A. Bertolin; I. Bloch; E. G. Boos; K. Borras; I. Brock; N. H. Brook; R. Brugnera; A. Bruni; P. J. Bussey; A. Caldwell; M. Capua; C. D. Catterall; J. Chwastowski; J. Ciborowski; R. Ciesielski; A. M. Cooper-Sarkar; M. Corradi; F. Corriveau; R. K. Dementiev; R. C. E. Devenish; G. Dolinska; S. Dusini; J. Figiel; B. Foster; G. Gach; E. Gallo; A. Garfagnini; A. Geiser; A. Gizhko; L. K. Gladilin; Yu. A. Golubkov; J. Grebenyuk; I. Gregor; G. Grzelak; O. Gueta; M. Guzik; W. Hain; D. Hochman; R. Hori; Z. A. Ibrahim; Y. Iga; M. Ishitsuka; A. Iudin; F. Januschek; N. Z. Jomhari; I. Kadenko; S. Kananov; U. Karshon; M. Kaur; P. Kaur; D. Kisielewska; R. Klanner; U. Klein; N. Kondrashova; O. Kononenko; Ie. Korol; I. A. Korzhavina; A. Kota?ski; U. Kötz; N. Kovalchuk; H. Kowalski; B. Krupa; O. Kuprash; M. Kuze; B. B. Levchenko; A. Levy; V. Libov; S. Limentani; M. Lisovyi; E. Lobodzinska; B. Löhr; E. Lohrmann; A. Longhin; D. Lontkovskyi; O. Yu. Lukina; I. Makarenko; J. Malka; S. Mergelmeyer; F. Mohamad Idris; N. Mohammad Nasir; V. Myronenko; K. Nagano; T. Nobe; D. Notz; R. J. Nowak; Yu. Onishchuk; E. Paul; W. Perla?ski; N. S. Pokrovskiy; M. Przybycie?; P. Roloff; I. Rubinsky; M. Ruspa; D. H. Saxon; M. Schioppa; W. B. Schmidke; U. Schneekloth; T. Schörner-Sadenius; L. M. Shcheglova; R. Shevchenko; O. Shkola; Yu. Shyrma; I. Singh; I. O. Skillicorn; W. S?omi?ski; A. Solano; L. Stanco; N. Stefaniuk; A. Stern; P. Stopa; J. Sztuk-Dambietz; D. Szuba; J. Szuba; E. Tassi; K. Tokushuku; J. Tomaszewska; A. Trofymov; T. Tsurugai; M. Turcato; O. Turkot; T. Tymieniecka; A. Verbytskyi; O. Viazlo; R. Walczak; W. A. T. Wan Abdullah; K. Wichmann; M. Wing; G. Wolf; S. Yamada; Y. Yamazaki; N. Zakharchuk; A. F. ?arnecki; L. Zawiejski; O. Zenaiev; B. O. Zhautykov; N. Zhmak; D. S. Zotkin

    2015-12-17

    Production of exclusive dijets in diffractive deep inelastic $e^\\pm p$ scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 372 pb$^{-1}$. The measurement was performed for $\\gamma^*-p$ centre-of-mass energies in the range $90 photon virtualities $Q^2 > 25$ GeV$^2$. Energy and transverse-energy flows around the jet axis are presented. The cross section is presented as a function of $\\beta$ and $\\phi$, where $\\beta=x/x_{\\rm I\\!P}$, $x$ is the Bjorken variable and $x_{\\rm I\\!P}$ is the proton fractional longitudinal momentum loss. The angle $\\phi$ is defined by the $\\gamma^*-$dijet plane and the $\\gamma^*-e^\\pm$ plane in the rest frame of the diffractive final state. The $\\phi$ cross section is measured in bins of $\\beta$. The results are compared to predictions from models based on different assumptions about the nature of the diffractive exchange.

  13. CT14QED PDFs from Isolated Photon Production in Deep Inelastic Scattering

    E-print Network

    Schmidt, Carl; Stump, Daniel; Yuan, C -P

    2015-01-01

    We describe the implementation of Quantum Electrodynamic (QED) evolution at Leading Order (LO) along with Quantum Chromodynamic (QCD) evolution at Next-to-Leading Order (NLO) in the CTEQ-TEA Global analysis package. The photon Parton Distribution Function (PDF) is described by a two-parameter ansatz, coming from radiation off the valence quarks, and based on the CT14 NLO PDFs. Setting the two parameters equal, allows us to completely specify the photon PDF in terms of the momentum fraction carried by the photon, $p_0^\\gamma$, at the initial scale $Q_0=1.295$ GeV. We obtain constraints on the photon PDF by comparing with ZEUS data~\\cite{Chekanov:2009dq} on the production of isolated photons in deep inelastic scattering, $ep\\rightarrow e\\gamma+X$. For this comparison we present a new perturbative calculation of the process that consistently combines the photon-initiated contribution with the quark-initiated contribution. Comparison with the data allows us to put a constraint at the 90% confidence level of $p_0^...

  14. CT14QED PDFs from Isolated Photon Production in Deep Inelastic Scattering

    E-print Network

    Carl Schmidt; Jon Pumplin; Daniel Stump; C. -P. Yuan

    2015-09-09

    We describe the implementation of Quantum Electrodynamic (QED) evolution at Leading Order (LO) along with Quantum Chromodynamic (QCD) evolution at Next-to-Leading Order (NLO) in the CTEQ-TEA Global analysis package. The photon Parton Distribution Function (PDF) is described by a two-parameter ansatz, coming from radiation off the valence quarks, and based on the CT14 NLO PDFs. Setting the two parameters equal, allows us to completely specify the photon PDF in terms of the momentum fraction carried by the photon, $p_0^\\gamma$, at the initial scale $Q_0=1.295$ GeV. We obtain constraints on the photon PDF by comparing with ZEUS data~\\cite{Chekanov:2009dq} on the production of isolated photons in deep inelastic scattering, $ep\\rightarrow e\\gamma+X$. For this comparison we present a new perturbative calculation of the process that consistently combines the photon-initiated contribution with the quark-initiated contribution. Comparison with the data allows us to put a constraint at the 90% confidence level of $p_0^\\gamma\\lesssim0.14\\%$ for the photon PDF at the initial scale of $Q_0=1.295$ GeV in the one-parameter radiative ansatz. The resulting CT14QED PDFs will be made available to the public.

  15. A transition state view on reactive scattering: Initial state-selected reaction probabilities for the H+CH4-->H2+CH3 reaction studied in full dimensionality

    NASA Astrophysics Data System (ADS)

    Schiffel, Gerd; Manthe, Uwe

    2010-11-01

    Initial state-selected reaction probabilities for the H+CH4?H2+CH3 reaction are computed for vanishing total angular momentum by full-dimensional calculations employing the multiconfigurational time-dependent Hartree approach. An ensemble of wave packets completely describing reactivity for total energies up to 0.58 eV is constructed in the transition state region by diagonalization of the thermal flux operator. These wave packets are then propagated into the reactant asymptotic region to obtain the initial state-selected reaction probabilities. Reaction probabilities for reactants in all rotational states of the vibrational 1A1, 1F2, and 1E levels of methane are presented. Vibrational excitation is found to decrease reactivity when reaction probabilities at equivalent total energies are compared but to increase reaction probabilities when the comparison is done at the basis of equivalent collision energies. Only a fraction of the initial vibrational energy can be utilized to promote the reaction. The effect of rotational excitation on the reactivity differs depending on the initial vibrational state of methane. For the 1A1 and 1F2 vibrational states of methane, rotational excitation decreases the reaction probability even when comparing reaction probabilities at equivalent collision energies. In contrast, rotational energy is even more efficient than translational energy in increasing the reaction probability when the reaction starts from the 1E vibrational state of methane. All findings can be explained employing a transition state based interpretation of the reaction process.

  16. Neutrino-Nucleon (Nucleus) Scattering for non-Neutrino Physics: The case of Neutral Current induced Photon Production

    NASA Astrophysics Data System (ADS)

    Zhang, Xilin

    2015-04-01

    Previously, I have studied the photon production in neutral current (NC) neutrino-nucleon (nucleus) scattering, and addressed its relevance to the MiniBooNE anomaly. (MiniBooNE is a short baseline neutrino oscillation experiment at FNAL.) In this talk I will review this topic, and discuss its connection to parity violating electron-nucleon scattering. Such electron scattering has been used in Qweak experiment at Jlab to measure precisely the proton weak charge. In addition, the nucleon-to-resonance excitations induced by both weak and electromagnetic currents play important roles in the NC photon production process. Understanding all these excitations in a unified microscopic framework is challenging. I will mention our effort along this line, and emphasize the complementarity between neutrino and electron scattering measurements of these excitations and their importance to improve our knowledge of nucleon structure. I acknowledge support from the US Department of Energy under grant DE-FG02-93ER-40756 and from Fermi National Accelerator Laboratory under Intensity Frontier Fellowship.

  17. P11 Resonances with Dubna-Mainz-Taipei dynamical model for ?N scattering and pion electromagnetic production

    NASA Astrophysics Data System (ADS)

    Yang, Shin Nan; Kamalov, S. S.; Tiator, L.

    2012-04-01

    We present the results on P11 resonances obtained with Dubna-Mainz-Taipei (DMT) dynamical model for pion-nucleon scattering and pion electromagnetic production. The extracted values agree well, in general, with PDG values. One pole is found corresponding to the Roper resonance and two more resonances are definitely needed in DMT model. We further find indication for a narrow P11 resonance at around 1700 MeV with a width ~ 50 MeV in both ?N and ?? reactions.

  18. Gamma ray production cross-sections associated with multiple inelastic scattering of 14 MeV neutrons in lead

    NASA Astrophysics Data System (ADS)

    Warner, P. C.; Cox, A. J.

    1985-11-01

    The gamma ray angular distributions and differential production cross-sections have been measured for the inelastic scattering of 14 MeV neutrons in lead, using a gamma ray spectrometer based on an associated particle time-of-flight gating technique. The variation of cross-section with sample thickness was measured and the results compared with the predictions of the Monte Carlo computer code MORSE.

  19. Aging Enhances the Production of Reactive Oxygen Species and Bactericidal Activity in Peritoneal Macrophages by Upregulating Classical Activation Pathways

    SciTech Connect

    Smallwood, Heather S.; Lopez-Ferrer, Daniel; Squier, Thomas C.

    2011-10-07

    Maintenance of macrophages in their basal state and their rapid activation in response to pathogen detection are central to the innate immune system, acting to limit nonspecific oxidative damage and promote pathogen killing following infection. To identify possible age-related alterations in macrophage function, we have assayed the function of peritoneal macrophages from young (3?4 months) and aged (14?15 months) Balb/c mice. In agreement with prior suggestions, we observe age-dependent increases in the extent of recruitment of macrophages into the peritoneum, as well as ex vivo functional changes involving enhanced nitric oxide production under resting conditions that contribute to a reduction in the time needed for full activation of senescent macrophages following exposure to lipopolysaccharides (LPS). Further, we observe enhanced bactericidal activity following Salmonella uptake by macrophages isolated from aged Balb/c mice in comparison with those isolated from young animals. Pathways responsible for observed phenotypic changes were interrogated using tandem mass spectrometry, which identified age-dependent increases in levels of proteins linked to immune cell pathways under basal conditions and following LPS activation. Immune pathways upregulated in macrophages isolated from aged mice include proteins critical to the formation of the immunoproteasome. Detection of these latter proteins is dramatically enhanced following LPS exposure for macrophages isolated from aged animals; in comparison, the identification of immunoproteasome subunits is insensitive to LPS exposure for macrophages isolated from young animals. Consistent with observed global changes in the proteome, quantitative proteomic measurements indicate that there are age-dependent abundance changes involving specific proteins linked to immune cell function under basal conditions. LPS exposure selectively increases the levels of many proteins involved in immune cell function in aged Balb/c mice. Collectively, these results indicate that macrophages isolated from old mice are in a preactivated state that enhances their sensitivities to LPS exposure. The hyper-responsive activation of macrophages in aged animals may act to minimize infection by general bacterial threats that arise due to age-dependent declines in adaptive immunity. However, this hypersensitivity and the associated increase in the level of formation of reactive oxygen species are likely to contribute to observed age-dependent increases in the level of oxidative damage that underlie many diseases of the elderly.

  20. Eicosanoids up-regulate production of reactive oxygen species by NADPH-dependent oxidase in Spodoptera exigua phagocytic hemocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eicosanoids mediate cellular immune responses in insects, including phagocytosis of invading microbes. Phagocytosis entails two major steps, the internalization of microbes and the subsequent killing of them via formation of reactive oxygen species (ROS). Here, we posed the hypothesis that eicosanoi...

  1. Spacecraft self-contamination due to back-scattering of outgas products

    NASA Technical Reports Server (NTRS)

    Robertson, S. J.

    1976-01-01

    The back-scattering of outgas contamination near an orbiting spacecraft due to intermolecular collisions was analyzed. Analytical tools were developed for making reasonably accurate quantitative estimates of the outgas contamination return flux, given a knowledge of the pertinent spacecraft and orbit conditions. Two basic collision mechanisms were considered: (1) collisions involving only outgas molecules (self-scattering) and (2) collisions between outgas molecules and molecules in the ambient atmosphere (ambient-scattering). For simplicity, the geometry was idealized to a uniformly outgassing sphere and to a disk oriented normal to the freestream. The method of solution involved an integration of an approximation of the Boltzmann kinetic equation known as the BGK (or Krook) model equation. Results were obtained in the form of simple equations relating outgas return flux to spacecraft and orbit parameters. Results were compared with previous analyses based on more simplistic models of the collision processes.

  2. Electron and Muon production cross-sections in quasielastic ?(?¯)-Nucleus scattering for E? < 1GeV

    NASA Astrophysics Data System (ADS)

    Akbar, F.; Alam, M. Rafi; Athar, M. Sajjad; Chauhan, S.; Singh, S. K.; Zaidi, F.

    2015-10-01

    In this paper, we have studied (anti)neutrino induced charged current quasielastic (CCQE) scattering from some nuclear targets in the energy region of E? < 1GeV. Our aim is to confront electron and muon production cross-sections relevant for ????e or ?¯???¯e oscillation experiments. The effects due to lepton mass and its kinematic implications, radiative corrections, second class currents (SCCs) and uncertainties in the axial and pseudoscalar form factors are calculated for (anti)neutrino induced reaction cross-sections on free nucleon as well as the nucleons bound in a nucleus where nuclear medium effects influence the cross-section. For the nuclear medium effects, we have taken some versions of Fermi gas model (FGM) available in the literature. The results for (anti)neutrino-nucleus scattering cross-section per interacting nucleons are compared with the corresponding results in free nucleon case.

  3. Identification and expression of the genes and purification and characterization of the gene products involved in reactivation of coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii.

    PubMed

    Seifert, C; Bowien, S; Gottschalk, G; Daniel, R

    2001-04-01

    The coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii is subject to suicide inactivation by the natural substrate glycerol during catalysis. We identified dhaF and dhaG as the genes responsible for reactivation of inactivated dehydratase. Northern blot analyses revealed that both genes were expressed during glycerol fermentation. The dhaF gene is transcribed together with the three structural genes coding for glycerol dehydratase (dhaBCE), whereas dhaG is coexpressed with the dhaT gene encoding 1,3-propanediol dehydrogenase. The dhaF and dhaG gene products were copurified to homogeneity from cell-free extracts of a recombinant E. coli strain producing both His6-tagged proteins. Both proteins formed a tight complex with an apparent molecular mass of 150 000 Da. The subunit structure of the native complex is probably alpha2beta2. The factor rapidly reactivated glycerol- or O2-inactivated hologlycerol dehydratase and activated the enzyme-cyanocobalamin complex in the presence of coenzyme B12, ATP, and Mg2+. The DhaF-DhaG complex and DhaF exhibited ATP-hydrolyzing activity, which was not directly linked to the reactivation of dehydratase. The purified DhaF-DhaG complex of C. freundii efficiently cross-activated the enzyme-cyanocobalamin complex and the glycerol-inactivated glycerol dehydratase of Klebsiella pneumoniae. It was not effective with respect to the glycerol dehydratase of Clostridium pasteurianum and to diol dehydratases of enteric bacteria. PMID:11298756

  4. Mitochondrial reactive oxygen species and cancer

    E-print Network

    Chandel, Navdeep S

    Mitochondria produce reactive oxygen species (mROS) as a natural by-product of electron transport chain activity. While initial studies focused on the damaging effects of reactive oxygen species, a recent paradigm shift ...

  5. Antiviral antibodies stimulate production of reactive oxygen species in cultured canine brain cells infected with canine distemper virus.

    PubMed

    Bürge, T; Griot, C; Vandevelde, M; Peterhans, E

    1989-06-01

    Canine distemper is characterized mainly by respiratory, enteric, and nervous symptoms. Infection of the central nervous system results in demyelination, to which inflammation has been shown to contribute significantly. It has been proposed that macrophages play a major role as effector cells in this process. We report that cultured dog brain cells contain a population of macrophages capable of producing reactive oxygen species as measured by luminol-dependent chemiluminescence. In cultures infected with canine distemper virus, a burst of reactive oxygen is triggered by antiviral antibody. This response depends on the presence of viral antigens on the surfaces of infected cells and is mediated by the interaction of antigen-bound antibody with Fc receptors on the macrophages. Since there is no evidence in vitro or in vivo that oligodendrocytes, the cells forming myelin, are infected, our observation supports the hypothesis that "innocent bystander killing" is important in demyelination caused by canine distemper virus. Reactive oxygen species released from macrophages may contribute to destruction of myelin. PMID:2724413

  6. Production and characterization of activated carbon prepared from safflower seed cake biochar and its ability to absorb reactive dyestuff

    NASA Astrophysics Data System (ADS)

    Ang?n, Dilek; Köse, T. Ennil; Selengil, U?ur

    2013-09-01

    The use of activated carbon obtained from biochar for the removal of reactive dyestuff from aqueous solutions at various contact times, pHs and temperatures was investigated. The biochar was chemically modified with potassium hydroxide. The surface area and micropore volume of activated carbon was 1277 m2/g and 0.4952 cm3/g, respectively. The surface characterization of both biochar and activated carbon was undertaken using by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental data indicated that the adsorption isotherms are well described by the Dubinin-Radushkevich (DR) isotherm equation. The adsorption kinetics of reactive dyestuff obeys the pseudo second-order kinetic model. The thermodynamic parameters such as ?G?, ?H? and ?S? were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 1.12 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal reactive dyestuff from wastewater.

  7. Exendin-4 Suppresses Src Activation and Reactive Oxygen Species Production in Diabetic Goto-Kakizaki Rat Islets in an Epac-Dependent Manner

    PubMed Central

    Mukai, Eri; Fujimoto, Shimpei; Sato, Hiroki; Oneyama, Chitose; Kominato, Rieko; Sato, Yuichi; Sasaki, Mayumi; Nishi, Yuichi; Okada, Masato; Inagaki, Nobuya

    2011-01-01

    OBJECTIVE Reactive oxygen species (ROS) is one of most important factors in impaired metabolism secretion coupling in pancreatic ?-cells. We recently reported that elevated ROS production and impaired ATP production at high glucose in diabetic Goto-Kakizaki (GK) rat islets are effectively ameliorated by Src inhibition, suggesting that Src activity is upregulated. In the present study, we investigated whether the glucagon-like peptide-1 signal regulates Src activity and ameliorates endogenous ROS production and ATP production in GK islets using exendin-4. RESEARCH DESIGN AND METHODS Isolated islets from GK and control Wistar rats were used for immunoblotting analyses and measurements of ROS production and ATP content. Src activity was examined by immunoprecipitation of islet lysates followed by immunoblotting. ROS production was measured with a fluorescent probe using dispersed islet cells. RESULTS Exendin-4 significantly decreased phosphorylation of Src Tyr416, which indicates Src activation, in GK islets under 16.7 mmol/l glucose exposure. Glucose-induced ROS production (16.7 mmol/l) in GK islet cells was significantly decreased by coexposure of exendin-4 as well as PP2, a Src inhibitor. The Src kinase–negative mutant expression in GK islets significantly decreased ROS production induced by high glucose. Exendin-4, as well as PP2, significantly increased impaired ATP elevation by high glucose in GK islets. The decrease in ROS production by exendin-4 was not affected by H-89, a PKA inhibitor, and an Epac-specific cAMP analog (8CPT-2Me-cAMP) significantly decreased Src Tyr416 phosphorylation and ROS production. CONCLUSIONS Exendin-4 decreases endogenous ROS production and increases ATP production in diabetic GK rat islets through suppression of Src activation, dependently on Epac. PMID:20978090

  8. Double-scattering mechanism of production of two $\\rho^0$ mesons in ultraperipheral, ultrarelativistic heavy ion collisions

    E-print Network

    Szczurek, Antoni

    2015-01-01

    We study, for the first time, differential distributions for two $\\rho^0$ meson production in exclusive ultraperipheral, ultrarelativistic heavy ion collisions via a double-scattering mechanism. The calculations are done in the impact parameter space. The cross section for $\\gamma A \\to \\rho^0 A$ is parametrized based on an existing model. Smearing of $\\rho^0$ masses is taken into account. The results of calculations for single and double-$\\rho^0$ production are compared to experimental data at the RHIC and LHC energies. The mechanism considered gives a significant contribution to the $AA \\to AA \\pi^+\\pi^-\\pi^+\\pi^-$ reaction. Some observables related to charged pions are presented too. We compare results of our calculations with the STAR collaboration results for four charged pion production.

  9. Combination and QCD analysis of charm production cross section measurements in deep-inelastic ep scattering at HERA

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Alexa, C.; Andreev, V.; Antonelli, S.; Antonioli, P.; Antonov, A.; Arneodo, M.; Arslan, O.; Aushev, V.; Aushev, Y.; Bachynska, O.; Baghdasaryan, A.; Baghdasaryan, S.; Bamberger, A.; Barakbaev, A. N.; Barbagli, G.; Bari, G.; Barreiro, F.; Bartel, W.; Bartosik, N.; Bartsch, D.; Basile, M.; Begzsuren, K.; Behnke, O.; Behr, J.; Behrens, U.; Bellagamba, L.; Belousov, A.; Belov, P.; Bertolin, A.; Bhadra, S.; Bindi, M.; Blohm, C.; Bokhonov, V.; Bondarenko, K.; Boos, E. G.; Borras, K.; Boscherini, D.; Bot, D.; Boudry, V.; Bozovic-Jelisavcic, I.; Bo?d, T.; Brümmer, N.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Britzger, D.; Brock, I.; Brownson, E.; Brugnera, R.; Bruni, A.; Bruni, G.; Brzozowska, B.; Bunyatyan, A.; Bussey, P. J.; Bylinkin, A.; Bylsma, B.; Bystritskaya, L.; Caldwell, A.; Campbell, A. J.; Cantun Avila, K. B.; Capua, M.; Carlin, R.; Catterall, C. D.; Ceccopieri, F.; Cerny, K.; Chekanov, S.; Chekelian, V.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; Contreras, J. G.; Cooper-Sarkar, A. M.; Coppola, N.; Corradi, M.; Corriveau, F.; Costa, M.; Cvach, J.; D'Agostini, G.; Dainton, J. B.; Dal Corso, F.; Daum, K.; Delvax, J.; Dementiev, R. K.; Derrick, M.; Devenish, R. C. E.; De Pasquale, S.; De Wolf, E. A.; del Peso, J.; Diaconu, C.; Dobre, M.; Dobur, D.; Dodonov, V.; Dolgoshein, B. A.; Dolinska, G.; Dossanov, A.; Doyle, A. T.; Drugakov, V.; Durkin, L. S.; Dusini, S.; Eckerlin, G.; Egli, S.; Eisenberg, Y.; Elsen, E.; Ermolov, P. F.; Eskreys, A.; Fang, S.; Favart, L.; Fazio, S.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrando, J.; Ferrero, M. I.; Figiel, J.; Fischer, D.-J.; Fleischer, M.; Fomenko, A.; Foster, B.; Gabathuler, E.; Gach, G.; Galas, A.; Gallo, E.; Garfagnini, A.; Gayler, J.; Geiser, A.; Ghazaryan, S.; Gialas, I.; Gizhko, A.; Gladilin, L. K.; Gladkov, D.; Glasman, C.; Glazov, A.; Goerlich, L.; Gogitidze, N.; Gogota, O.; Golubkov, Y. A.; Göttlicher, P.; Gouzevitch, M.; Grab, C.; Grabowska-Bo?d, I.; Grebenyuk, A.; Grebenyuk, J.; Greenshaw, T.; Gregor, I.; Grigorescu, G.; Grindhammer, G.; Grzelak, G.; Gueta, O.; Guzik, M.; Gwenlan, C.; Hüttmann, A.; Haas, T.; Habib, S.; Haidt, D.; Hain, W.; Hamatsu, R.; Hart, J. C.; Hartmann, H.; Hartner, G.; Henderson, R. C. W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hilger, E.; Hiller, K. H.; Hladký, J.; Hochman, D.; Hoffmann, D.; Hori, R.; Horisberger, R.; Hreus, T.; Huber, F.; Ibrahim, Z. A.; Iga, Y.; Ingbir, R.; Ishitsuka, M.; Jacquet, M.; Jakob, H.-P.; Janssen, X.; Januschek, F.; Jones, T. W.; Jönsson, L.; Jüngst, M.; Jung, A. W.; Jung, H.; Kadenko, I.; Kahle, B.; Kananov, S.; Kanno, T.; Kapichine, M.; Karshon, U.; Karstens, F.; Katkov, I. I.; Kaur, P.; Kaur, M.; Kenyon, I. R.; Keramidas, A.; Khein, L. A.; Kiesling, C.; Kim, J. Y.; Kisielewska, D.; Kitamura, S.; Klanner, R.; Klein, M.; Klein, U.; Kleinwort, C.; Kötz, U.; Koffeman, E.; Kogler, R.; Kondrashova, N.; Kononenko, O.; Kooijman, P.; Korol, I.; Korzhavina, I. A.; Kostka, P.; Kota?ski, A.; Kowalski, H.; Krämer, M.; Kretzschmar, J.; Krüger, K.; Kuprash, O.; Kuze, M.; Landon, M. P. J.; Lange, W.; Laštovi?ka-Medin, G.; Laycock, P.; Lebedev, A.; Lee, A.; Lendermann, V.; Levchenko, B. B.; Levonian, S.; Levy, A.; Libov, V.; Limentani, S.; Ling, T. Y.; Lipka, K.; Lisovyi, M.; List, B.; List, J.; Lobodzinska, E.; Lobodzinski, B.; Löhr, B.; Lohmann, W.; Lohrmann, E.; Long, K. R.; Longhin, A.; Lontkovskyi, D.; Lopez-Fernandez, R.; Lubimov, V.; Lukina, O. Y.; Maeda, J.; Magill, S.; Makarenko, I.; Malinovski, E.; Malka, J.; Mankel, R.; Margotti, A.; Marini, G.; Martin, J. F.; Martyn, H.-U.; Mastroberardino, A.; Mattingly, M. C. K.; Maxfield, S. J.; Mehta, A.; Melzer-Pellmann, I.-A.; Mergelmeyer, S.; Meyer, A. B.; Meyer, H.; Meyer, J.; Miglioranzi, S.; Mikocki, S.; Milcewicz-Mika, I.; Mohamad Idris, F.; Monaco, V.; Montanari, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Morris, J. D.; Mujkic, K.; Müller, K.; Musgrave, B.; Nagano, K.; Namsoo, T.; Nania, R.; Naumann, T.; Newman, P. R.; Niebuhr, C.; Nigro, A.; Nikitin, D.; Ning, Y.; Nobe, T.; Notz, D.; Nowak, G.; Nowak, K.; Nowak, R. J.; Nuncio-Quiroz, A. E.; Oh, B. Y.; Okazaki, N.; Olkiewicz, K.; Olsson, J. E.; Onishchuk, Y.; Ozerov, D.; Pahl, P.; Palichik, V.; Pandurovic, M.; Papageorgiu, K.; Parenti, A.; Pascaud, C.; Patel, G. D.; Paul, E.; Pawlak, J. M.; Pawlik, B.; Pelfer, P. G.; Pellegrino, A.; Perez, E.; Perla?ski, W.; Perrey, H.; Petrukhin, A.; Picuric, I.; Piotrzkowski, K.; Pirumov, H.; Pitzl, D.; Pla?akyt?, R.; Pluci?ski, P.; Pokorny, B.; Pokrovskiy, N. S.; Polifka, R.; Polini, A.; Povh, B.; Proskuryakov, A. S.; Przybycie?, M.; Radescu, V.; Raicevic, N.; Raval, A.

    2013-02-01

    Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections ?_red^{cbar{c}} for charm production are obtained in the kinematic range of photon virtuality 2.5? Q 2?2000 GeV2 and Bjorken scaling variable 3?10-5? x?5?10-2. The combination method accounts for the correlations of the systematic uncertainties among the different data sets. The combined charm data together with the combined inclusive deep-inelastic scattering cross sections from HERA are used as input for a detailed NLO QCD analysis to study the influence of different heavy flavour schemes on the parton distribution functions. The optimal values of the charm mass as a parameter in these different schemes are obtained. The implications on the NLO predictions for W ± and Z production cross sections at the LHC are investigated. Using the fixed flavour number scheme, the running mass of the charm quark is determined.

  10. Impulsive model for reactive collisions

    NASA Technical Reports Server (NTRS)

    Marron, M. T.; Bernstein, R. B.

    1972-01-01

    A simple classical mechanical model of the reactive scattering of a structureless atom A and a quasi-diatomic BC is developed which takes full advantage of energy, linear and angular momentum conservation relations but introduces a minimum of further assumptions. These are as follows: (1) the vibrational degree of freedom of the reactant (BC) and product (AB) molecules is suppressed, so the change in vibrational energy is simply a parameter; (2) straight-line trajectories are assumed outside of a reaction shell; (3) within this zone, momentum transfer occurs impulsively (essentially instantaneously) following mass transfer; (4) the impulse, which may be either positive or negative, is directed along the BC axis, which may, however, assume all orientations with respect to the incident relative velocity. The model yields differential and total cross sections and product rotational energy distributions for a given collision exoergicity Q, or for any known distribution over Q. Numerical results are presented for several prototype reactions whose dynamics have been well-studied.

  11. Production and characterization of thermoplastic cassava starch, functionalized poly(lactic acid), and their reactive compatibilized blends

    NASA Astrophysics Data System (ADS)

    Detyothin, Sukeewan

    Cassava starch was blended with glycerol using a co-rotating twin-screw extruder (TSE). Thermoplastic cassava starch (TPCS) at a ratio of 70/30 by weight of cassava/glycerol was selected and further blended with other polymers. TPCS sheets made from compression molding had low tensile strength (0.45 +/- 0.05 MPa) and Young's modulus (1.24 +/- 0.58 MPa), but moderate elongation at break (83.0 +/- 0.18.6%), medium level of oxygen permeability, and high water vapor permeability with a very high rate of water absorption. TPCS was blended with poly(lactic acid) (PLA) at various ratios by using a TSE. The blend resins exhibited good properties such as increased thermal stability (Tmax) and crystallinity of PLA, and improved water sensitivity and processability of TPCS. PLA and TPCS exhibited a high interfacial tension between the two phases of 7.9 mJ·m -2, indicating the formation of an incompatible, immiscible blend. SEM micrographs showed a non-homogeneous distribution of TPCS droplets in the PLA continuous phase. TEM micrographs of the blend films made by cast-film extrusion showed coalescence of the TPCS droplets in the PLA continuous phase of the blend, indicating that the compatibility between the polymer pair needs to be improved. A response surface methodology (RSM) design was used to analyze the effects of maleic anhydride (MA) and 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox or L101) contents, and TSE screw speed on the degree of grafted MA and number average molecular weight (Mn) of functionalized PLA (PLA-g-MA), a reactive compatibilizer. PLA-g- MA made by reactive extrusion had an array of colors depending on the content of L101 and MA used. New FTIR peaks suggested that MA was grafted onto the PLA backbone and oligomeric MA may occur. Increasing L101 increased the degree of grafting and decreased Mn, but the Mn of the PLA-g-MA's produced with a high amount of L101 was stable during storage. MA exhibited an optimum concentration for maximizing the degree of grafted MA, and increasing MA content retarded the reduction of Mn during processing. However, the Mn of PLA-g-MA during storage decreased more rapidly with a high content of MA. TSE screw speed had an impact on the Mn with the maximum value predicted at 20 rpm. PLA-g-MA compounds differing in Mn and/or grafted MA content were used as reactive polymers with TPCS (to produce binary blends) and as reactive compatibilizers (to produce ternary blends of PLA/TPCS/PLA-g-MA) with TPCS content of 30 wt% using a TSE. As a result of maleation, PLA-g-MA had a higher grafted MA content with a lower Mn, and higher PI. The interaction of anhydride groups from PLA-g-MA and hydroxyl groups from TPCS was found by FTIR. The reactive binary blends exhibited a change in thermal stability, decrease of Tcc, the presence of double melting peaks, and an increase of the Tgs of glycerol and starch. The higher the grafted MA content and/or the higher Mn of the PLA- g-MA used, the better were the distribution and smaller the TPCS domains obtained in the blends. The highest elongation at break was achieved when 30 wt% TPCS was blended with 70 wt% of PLA having 0.1 wt% of grafted MA and Mn of PLA-g-MA with a 45 kDa. Finally, the optimum PLA-g-MA was determined by using the results from PLA-g-MA RSM design and the reactive blending.

  12. Observation by flow sup 1 H NMR and dimerization kinetics and products of reactive ortho-quinodimethanes and benzocyclobutadiene

    SciTech Connect

    Fischer, D.

    1990-09-21

    The reactive o-quinodimethanes, 1,2-dimethylene-1,2-dihydronaphthalene (9) and o-xylylene (1) were observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum of 9 was obtained in the absence of precursor and dimers. However, the {sup 1}H NMR spectrum of the more reactive 1, generated in a similar manner from (o-((trimethylsilyl)methyl)benzyl)trimethylammonium iodide (5.) could be obtained only in the presence of its stable (4 + 2) and (4 + 4) dimers. The dimerization kinetics of 3-methyl- (5{prime}), 3,6-dimethyl- (11), 3-isopropyl- (12), and 3,6-diisoproply-1,2-xylylene (13) in acetonitrile (CH{sub 3}CN) were studied by stopped-flow UV-visible spectroscopy. Fluoride ion induced 1,2-elimination from 2-elimination from 2-trimethylsilylbenzocyclobutenyl-1 mesylate (26) was used to generate the reactive molecule benzocyclobutadiene (1{prime}) in CD{sub 3}CN, which was observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum (in CD{sub 3}CN) of 1,2-dimethylene-1,2-dihydrothiophene (1{double prime}), obtained by fluoride ion induced 1,4-elimination from 3-(trimethylammoniummethyl)-2-(trimethylsilylmethyl)thiophene iodine was observed by flow {sup 1}H NMR spectroscopy at room temperature. The dimerization rate of 1{double prime} in CH{sub 3}CN, generated in the same manner, was measured by UV-visible spectroscopy. 166 refs., 7 figs., 7 tabs.

  13. Polyphosphate-enhanced production of reactive oxidants by nanoparticulate zero-valent iron and ferrous ion in the presence of oxygen: Yield and nature of oxidants.

    PubMed

    Kim, Hak-Hyeon; Lee, Hongshin; Kim, Hyung-Eun; Seo, Jiwon; Hong, Seok Won; Lee, Jeong-Yong; Lee, Changha

    2015-12-01

    The production of reactive oxidants from nanoparticulate zero-valent iron (nZVI) and ferrous ion (Fe(II)) in the presence of oxygen was greatly enhanced by the addition of tetrapolyphosphate (TPP) as an iron-chelating agent. Compared to other ligands, TPP exhibited superior activity in improving the oxidant yields. The nZVI/TPP/O2 and the Fe(II)/TPP/O2 systems showed similar oxidant yields with respect to the iron consumed, indicating that nZVI only serves as a source of Fe(II). The degradation efficacies of selected organic compounds were also similar in the two systems. It appeared that both hydroxyl radical (OH) and ferryl ion (Fe(IV)) are produced, and OH dominates at acidic pH. However, at pH > 6, little occurrence of hydroxylated oxidation products suggests that Fe(IV) is a dominant oxidant. The degradation rates of selected organic compounds by the Fe(II)/TPP/O2 system had two optimum points at pH 6 and 9, and these pH-dependent trends are likely attributed to the speciation of Fe(IV) with different reactivities. PMID:26093796

  14. TCDD decreases ATP levels and increases reactive oxygen production through changes in mitochondrial F F{sub 1}-ATP synthase and ubiquinone

    SciTech Connect

    Shertzer, Howard G. . E-mail: shertzhg@ucmail.uc.edu; Genter, Mary Beth; Shen, Dongxiao; Nebert, Daniel W.; Chen, Ying; Dalton, Timothy P.

    2006-12-15

    Mitochondria generate ATP and participate in signal transduction and cellular pathology and/or cell death. TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) decreases hepatic ATP levels and generates mitochondrial oxidative DNA damage, which is exacerbated by increasing mitochondrial glutathione redox state and by inner membrane hyperpolarization. This study identifies mitochondrial targets of TCDD that initiate and sustain reactive oxygen production and decreased ATP levels. One week after treating mice with TCDD, liver ubiquinone (Q) levels were significantly decreased, while rates of succinoxidase and Q-cytochrome c oxidoreductase activities were increased. However, the expected increase in Q reduction state following TCDD treatment did not occur; instead, Q was more oxidized. These results could be explained by an ATP synthase defect, a premise supported by the unusual finding that TCDD lowers ATP/O ratios without concomitant changes in respiratory control ratios. Such results suggest either a futile cycle in ATP synthesis, or hydrolysis of newly synthesized ATP prior to release. The TCDD-mediated decrease in Q, concomitant with an increase in respiration, increases complex 3 redox cycling. This acts in concert with glutathione to increase membrane potential and reactive oxygen production. The proposed defect in ATP synthase explains both the greater respiratory rates and the lower tissue ATP levels.

  15. C60-Fullerene monomalonate adducts selectively inactivate neuronal nitric oxide synthase by uncoupling the formation of reactive oxygen intermediates from nitric oxide production.

    PubMed

    Wolff, D J; Mialkowski, K; Richardson, C F; Wilson, S R

    2001-01-01

    C(60)-Fullerene monomalonate adducts inactivate selectively the neuronal nitric oxide synthase isoform in a manner completely preventable by the concurrent presence of superoxide dismutase and catalase. This inactivation is time-, fullerene concentration-, and turnover-dependent and is not reversible by dilution. The di(carboxypropan-3-ol)methano-[60]-fullerene (diol adduct) has no effect on NADPH consumption by nNOS as measured in the absence of arginine substrate, but dramatically increases NADPH consumption in the presence of arginine. This fullerene-enhanced NADPH consumption is linked to oxygen as electron acceptor and is accompanied by the increased production of hydrogen peroxide. These effects of fullerene monomalonate adducts are unique to the nNOS isoform and are not observed using either the iNOS or the eNOS isoform. The inhibitory effects of fullerene monomalonate adducts are unaltered and insurmountable by increased concentrations of arginine, tetrahydrobiopterin, or calmodulin. These observations indicate that fullerene monomalonate adducts uncouple in the presence of arginine the formation of reactive oxygen intermediates from NO production by nNOS. These reactive oxygen intermediates dissociate from the enzyme and, acting from solution, inactivate NOS NO forming activity. PMID:11141054

  16. Plastid Genome Instability Leads to Reactive Oxygen Species Production and Plastid-to-Nucleus Retrograde Signaling in Arabidopsis1[C][W][OPEN

    PubMed Central

    Lepage, Étienne; Zampini, Éric; Brisson, Normand

    2013-01-01

    The plastid genome is highly conserved among plant species, suggesting that alterations of its structure would have dramatic impacts on plant fitness. Nevertheless, little is known about the direct consequences of plastid genome instability. Recently, it was reported that the plastid Whirly proteins WHY1 and WHY3 and a specialized type-I polymerase, POLIB, act as safeguards against plastid genome instability in Arabidopsis (Arabidopsis thaliana). In this study, we use ciprofloxacin, an organelle double-strand break-inducing agent, and the why1why3polIb-1 variegated mutant to evaluate the impact of generalized plastid DNA instability. First, we show that in why1why3polIb-1 and ciprofloxacin-treated plants, plastid genome instability is associated with increased reactive oxygen species production. Then, using different light regimens, we show that the elevated reactive oxygen species production correlates with the appearance of a yellow-variegated phenotype in the why1why3polIb-1 population. This redox imbalance also correlates to modifications of nuclear gene expression patterns, which in turn leads to acclimation to high light. Taken together, these results indicate that plastid genome instability induces an oxidative burst that favors, through nuclear genetic reprogramming, adaptation to subsequent oxidative stresses. PMID:23969600

  17. IgE-mediated allergic reactions to fruit gums and investigation of cross-reactivity between gelatine and modified gelatine-containing products.

    PubMed

    Wahl, R; Kleinhans, D

    1989-01-01

    A 32-year-old female reacted with a contact urticaria syndrome after eating 'gummy bears' (fruit gums). The reaction began in the oral mucosa and led to treatment on an inpatient basis. RAST measurements with allergen discs produced with gelatine and gelatine-containing products (among them 'gummy bears') demonstrated the presence of IgE antibodies in the serum of this patient. Proteins with molecular weights in the range of 40-120 kD were identified as the allergens in gelatine by using Western blot analysis. RAST inhibition showed cross-reactivity between gelatine, gelatine-containing products and the modified gelatine used in some plasma substitutes. Allergic reactions towards coloured fruit candies and 'gummy bears' may result from an IgE-mediated hypersensitivity towards gelatine. The long-known anaphylactoid reactions towards gelatine-containing plasma substitutes may, at least in part, be of an allergic nature. PMID:2702514

  18. Phenylethynyl terminated reactive oligomer

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor); Jensen, Brian J. (Inventor); Hergenrother, Paul M. (Inventor)

    1995-01-01

    A composition of matter having the general structure: ##STR1## (wherein X is F, Cl, or NO.sub.2, and Y is CO, SO.sub.2 or C(CF.sub.3).sub.2) is employed to terminate a nucleophilic reagent, resulting in the exclusive production of phenylethynyl terminated reactive oligomers which display unique thermal characteristics. A reactive diluent having the general structure: ##STR2## (wherein R is any aliphatic or aromatic moiety) is employed to decrease the melt viscosity of a phenylethynyl terminated reactive oligomer and to subsequently react therewith to provide a thermosetting material of enhanced density. These materials have features which make them attractive candidates for use as composite matrices and adhesives.

  19. Forward-jet production in deep inelastic ep scattering at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Jechow, M.; Pavel, N.; Yagües Molina, A. G.; Antonelli, S.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Bindi, M.; Boscherini, D.; Bruni, A.; Bruni, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Kind, O. M.; Nuncio-Quiroz, A. E.; Paul, E.; Renner, R.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Ibrahim, Z. A.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Gil, M.; Olkiewicz, K.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Blohm, C.; Bonato, A.; Borras, K.; Ciesielski, R.; Coppola, N.; Dossanov, A.; Drugakov, V.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Horn, C.; Hüttmann, A.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Santamarta, R.; Schneekloth, U.; Spiridonov, A.; Stadie, H.; Szuba, D.; Szuba, J.; Theedt, T.; Wolf, G.; Wrona, K.; Youngman, C.; Zeuner, W.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Gosau, T.; Holm, U.; Klanner, R.; Lohrmann, E.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Wichmann, K.; Wick, K.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Borodin, M.; Kozulia, A.; Lisovyi, M.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Zambrana, M.; Corriveau, F.; Liu, C.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Kollar, D.; Schmidke, W. B.; Sutiak, J.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Ferrando, J.; Foster, B.; Korcsak-Gorzo, K.; Oliver, K.; Patel, S.; Roberfroid, V.; Robertson, A.; Straub, P. B.; Uribe-Estrada, C.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Oh, B. Y.; Raval, A.; Ukleja, J.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Ingbir, R.; Kananov, S.; Levy, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Boutle, S. K.; Butterworth, J. M.; Gwenlan, C.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Tymieniecka, T.; Ukleja, A.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Giller, I.; Hochman, D.; Karshon, U.; Rosin, M.; Brownson, E.; Danielson, T.; Everett, A.; Kçira, D.; Reeder, D. D.; Ryan, P.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.

    2007-11-01

    Forward jet cross sections have been measured in neutral current deep inelastic scattering at low Bjorken-x with the ZEUS detector at HERA using an integrated luminosity of 81.8 pb-1. Measurements are presented for inclusive forward jets as well as for forward jets accompanied by a dijet system. The explored phase space, with jet pseudorapidity up to 4.3 is expected to be particularly sensitive to the dynamics of QCD parton evolution at low x. The measurements are compared to fixed-order QCD calculations and to leading-order parton-shower Monte Carlo models.

  20. Soft X-ray production by photon scattering in pulsating binary neutron star sources

    NASA Technical Reports Server (NTRS)

    Bussard, R. W.; Meszaros, P.; Alexander, S.

    1985-01-01

    A new mechanism is proposed as a source of soft (less than 1 keV) radiation in binary pulsating X-ray sources, in the form of photon scattering which leaves the electron in an excited Landau level. In a plasma with parameters typical of such sources, the low-energy X-ray emissivity of this mechanism far exceeds that of bremsstrahlung. This copious source of soft photons is quite adequate to provide the seed photons needed to explain the power-law hard X-ray spectrum by inverse Comptonization on the hot electrons at the base of the accretion column.

  1. Photosensitization of CdSe/ZnS QDs and reliability of assays for reactive oxygen species production.

    SciTech Connect

    Cooper, D. R.; Dimitrijevic, N. M.; Nadeau, J. L.; McGill Univ.

    2010-01-01

    CdSe/ZnS quantum dots (QDs) conjugated to biomolecules that can act as electron donors are said to be 'photosensitized': that is, they are able to oxidize or reduce molecules whose redox potential lies inside their band edges, in particular molecular oxygen and water. This leads to the formation of reactive oxygen species (ROS) and phototoxicity. In this work, we quantify the generation of different forms of ROS from as-synthesized QDs in toluene; water-solubilized, unconjugated QDs; QDs conjugated to the neurotransmitter dopamine; and dopamine alone. Results of indirect fluorescent ROS assays, both in solution and inside cells, are compared with those of spin-trap electron paramagentic resonance spectroscopy (EPR). The effect of these particles on the metabolism of mammalian cells is shown to be dependent upon light exposure and proportional to the amount of ROS generated.

  2. AMPK is involved in mediation of erythropoietin influence on metabolic activity and reactive oxygen species production in white adipocytes.

    PubMed

    Wang, Li; Di, Lijun; Noguchi, Constance Tom

    2014-09-01

    Erythropoietin, discovered for its indispensable role during erythropoiesis, has been used in therapy for selected red blood cell disorders in erythropoietin-deficient patients. The biological activities of erythropoietin have been found in animal models to extend to non-erythroid tissues due to the expression of erythropoietin receptor. We previously demonstrated that erythropoietin promotes metabolic activity and white adipocytes browning to increase mitochondrial function and energy expenditure via peroxisome proliferator-activated receptor alpha and Sirtuin1. Here we report that AMP-activated protein kinase was activated by erythropoietin possibly via Ca(2+)/calmodulin-dependent protein kinase kinase in adipocytes as well as in white adipose tissue from diet induced obese mice. Erythropoietin increased cellular nicotinamide adenine dinucleotide via increased AMP-activated protein kinase activity, possibly leading to Sirtuin1 activation. AMP-activated protein kinase knock down reduced erythropoietin mediated increase in cellular oxidative function including the increased oxygen consumption rate, fatty acid utilization and induction of key metabolic genes. Under hypoxia, adipocytes were found to generate more reactive oxygen species, and erythropoietin reduced the reactive oxygen species and increased antioxidant gene expression, suggesting that erythropoietin may provide protection from oxidative stress in adipocytes. Erythropoietin also reversed increased nicotinamide adenine dinucleotide by hypoxia via increased AMP-activated protein kinase. Additionally, AMP-activated protein kinase is found to be involved in erythropoietin stimulated increase in oxygen consumption rate, fatty acid oxidation and mitochondrial gene expression. AMP-activated protein kinase knock down impaired erythropoietin stimulated increases in antioxidant gene expression. Collectively, our findings identify the AMP-activated protein kinase involvement in erythropoietin signaling in regulating adipocyte cellular redox status and metabolic activity. PMID:24953559

  3. Structural Insights into 2,2?-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS)-Mediated Degradation of Reactive Blue 21 by Engineered Cyathus bulleri Laccase and Characterization of Degradation Products

    PubMed Central

    Kenzom, T.; Srivastava, P.

    2014-01-01

    Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2?-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)]. This laccase was engineered to degrade effectively reactive blue 21 (RB21), a phthalocyanine dye reported to be decolorized only by peroxidases. The 816-bp segment (toward the C terminus) of the lcc gene was subjected to random mutagenesis and enzyme variants (Lcc35, Lcc61, and Lcc62) were selected based on increased ABTS oxidizing ability. Around 78 to 95% decolorization of RB21 was observed with the ABTS-supplemented Lcc variants in 30 min. Analysis of the degradation products by mass spectrometry indicated the formation of several low-molecular-weight compounds. Mapping the mutations on the modeled structure implicated residues both near and far from the T1 Cu site that affected the catalytic efficiency of the mutant enzymes on ABTS and, in turn, the rate of oxidation of RB21. Several inactive clones were also mapped. The importance of geometry as well as electronic changes on the reactivity of laccases was indicated. PMID:25261507

  4. Structural insights into 2,2'-azino-Bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-mediated degradation of reactive blue 21 by engineered Cyathus bulleri Laccase and characterization of degradation products.

    PubMed

    Kenzom, T; Srivastava, P; Mishra, S

    2014-12-01

    Advanced oxidation processes are currently used for the treatment of different reactive dyes which involve use of toxic catalysts. Peroxidases are reported to be effective on such dyes and require hydrogen peroxide and/or metal ions. Cyathus bulleri laccase, expressed in Pichia pastoris, catalyzes efficient degradation (78 to 85%) of reactive azo dyes (reactive black 5, reactive orange 16, and reactive red 198) in the presence of synthetic mediator ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)]. This laccase was engineered to degrade effectively reactive blue 21 (RB21), a phthalocyanine dye reported to be decolorized only by peroxidases. The 816-bp segment (toward the C terminus) of the lcc gene was subjected to random mutagenesis and enzyme variants (Lcc35, Lcc61, and Lcc62) were selected based on increased ABTS oxidizing ability. Around 78 to 95% decolorization of RB21 was observed with the ABTS-supplemented Lcc variants in 30 min. Analysis of the degradation products by mass spectrometry indicated the formation of several low-molecular-weight compounds. Mapping the mutations on the modeled structure implicated residues both near and far from the T1 Cu site that affected the catalytic efficiency of the mutant enzymes on ABTS and, in turn, the rate of oxidation of RB21. Several inactive clones were also mapped. The importance of geometry as well as electronic changes on the reactivity of laccases was indicated. PMID:25261507

  5. Peneciraistin C induces caspase-independent autophagic cell death through mitochondrial-derived reactive oxygen species production in lung cancer cells.

    PubMed

    Pan, Xiaohong; Liu, Desheng; Wang, Juan; Zhang, Xiuli; Yan, Miaomiao; Zhang, Dehai; Zhang, Jinjin; Liu, Weizhong

    2013-11-01

    Peneciraistin C (Pe-C) is a novel spiroketal compound isolated from the saline soil derived fungus Penicillium raistrickii. Our previous study showed that Pe-C exerted a potent cytotoxic effect on many kinds of cancer cell lines, especially on human lung cancer A549 cells. Here, we report the anticancer mechanisms of Pe-C in a variety of lung cancer cells. The results showed that Pe-C induced caspase-independent autophagic cell death and elevated mitochondrial-derived reactive oxygen species levels. Interestingly, if autophagy was blocked by 3-methyladenine or Atg5 siRNA, Pe-C triggered a shift from autophagic cell death into caspase-dependent apoptotic cell death. In addition, cotreatment with the antioxidant N-acetyl-(L)-cysteine or Mito-TEMPO could effectively reverse the effect of the enhanced reactive oxygen species production, which in turn almost completely prevented the cell death induced by Pe-C. Thus, this study provided new insights into the mechanisms underlying Pe-C-mediated cell death, which indicated that Pe-C could be a potential drug candidate for therapy of lung cancers. PMID:23952056

  6. Winery by-products: extraction optimization, phenolic composition and cytotoxic evaluation to act as a new source of scavenging of reactive oxygen species.

    PubMed

    Melo, Priscilla Siqueira; Massarioli, Adna Prado; Denny, Carina; dos Santos, Luciana Ferracini; Franchin, Marcelo; Pereira, Giuliano Elias; Vieira, Thais Maria Ferreira de Souza; Rosalen, Pedro Luiz; de Alencar, Severino Matias

    2015-08-15

    Nearly 20 million tons of winery by-products, with many biological activities, are discarded each year in the world. The extraction of bioactive compounds from Chenin Blanc, Petit Verdot, and Syrah grape by-products, produced in the semi-arid region in Brazil, was optimized by a Central Composite Rotatable Design. The phenolic compounds profile, antioxidant capacity against synthetic free radicals (DPPH and ABTS), reactive oxygen species (ROS; peroxyl radical, superoxide radical, hypochlorous acid), cytotoxicity assay (MTT) and quantification of TNF-? production in RAW 264.7 cells were conducted. Gallic acid, syringic acid, procyanidins B1 and B2, catechin, epicatechin, epicatechin gallate, quercetin 3-?-d-glucoside, delfinidin 3-glucoside, peonidin 3-O-glucoside, and malvidin 3-glucoside were the main phenolic compounds identified. In general, rachis showed higher antioxidant capacity than pomace extract, especially for Chenin Blanc. All extracts showed low cytotoxicity against RAW 264.7 cells and Petit Verdot pomace suppressed TNF-? liberation in vitro. Therefore, these winery by-products can be considered good sources of bioactive compounds, with great potential for application in the food and pharmaceutical industries. PMID:25794735

  7. Deep-inelastic scattering and the operator product expansion in lattice QCD

    E-print Network

    William Detmold; C. -J. David Lin

    2005-12-13

    We discuss the determination of deep-inelastic hadron structure in lattice QCD. By using a fictitious heavy quark, direct calculations of the Compton scattering tensor can be performed in Euclidean space that allow the extraction of the moments of structure functions. This overcomes issues of operator mixing and renormalisation that have so far prohibited lattice computations of higher moments. This approach is especially suitable for the study of the twist-two contributions to isovector quark distributions, which is practical with current computing resources. While we focus on the isovector unpolarised distribution, our method is equally applicable to other quark distributions and to generalised parton distributions. By looking at matrix elements such as $$ (where $V^\\mu$ and $A^\

  8. Searching for and exploring double-parton scattering effects in four-jet production at the LHC

    NASA Astrophysics Data System (ADS)

    Maciu?a, Rafa?; Szczurek, Antoni

    2015-10-01

    We discuss four-jet production at the LHC. We calculate cross section for both single-parton scattering (SPS) using the ALPGEN code and for double-parton scattering (DPS) in leading-order collinear approach. Our results are compared with experimental data obtained recently by the CMS Collaboration. We show that the ALPGEN code relatively well describes distributions in transverse momenta and rapidity of each of the four jets ordered by their transverse momenta (leading, subleading, etc.). The SPS mechanism does not explain the distributions at large rapidity for the leading jet. The DPS mechanism improves the agreement with the experimental data in this corner of the phase space. In order to enhance the relative DPS contribution we propose to impose different cuts. The relative DPS contribution increases when decreasing the lower cut on the jet transverse momenta as well as when a low lower cut on the rapidity distance between the most remote jets is imposed. We predict very flat distribution in azimuthal angle between the most remote jets with low lower cuts on jets transverse momentum. We find phase-space corners where the DPS content is enhanced relatively to the SPS one.

  9. Shear-Induced Reactive Gelation.

    PubMed

    Brand, Bastian; Morbidelli, Massimo; Soos, Miroslav

    2015-11-24

    In this work, we describe a method for the production of porous polymer materials in the form of particles characterized by narrow pore size distribution using the principle of shear-induced reactive gelation. Poly(styrene-co-divinylbenzene) primary particles with diameter ranging from 80 to 200 nm are used as building blocks, which are assembled into fractal-like clusters when exposed to high shear rates generated in a microchannel. It was found that independent of the primary particle size, it is possible to modulate the internal structure of formed fractal-like aggregates having fractal dimension ranging from 2.4 to 2.7 by varying the residence time in the microchannel. Thermally induced postpolymerization was used to increase the mechanical resilience of such formed clusters. Primary particle interpenetration was observed by SEM and confirmed by light scattering resulting in an increase of fractal dimension. Nitrogen sorption measurements and mercury porosimetry confirmed formation of a porous material with surface area ranging from 20 to 40 m(2)/g characterized by porosity of 70% and narrow pore size distribution with an average diameter around 700 nm without the presence of any micropores. The strong perfusive character of the synthesized material was confirmed by the existence of a plateau of the height equivalent to a theoretical plate measured at high reduced velocities using a chromatographic column packed with the synthesized microclusters. PMID:26488233

  10. Azoxystrobin-induced excessive reactive oxygen species (ROS) production and inhibition of photosynthesis in the unicellular green algae Chlorella vulgaris.

    PubMed

    Liu, Lei; Zhu, Bin; Wang, Gao-Xue

    2015-05-01

    This study investigated the short-term toxicity of azoxystrobin (AZ), one of strobilurins used as an effective fungicidal agent to control the Asian soybean rust, on aquatic unicellular algae Chlorella vulgaris. The median percentile inhibition concentration (IC??) of AZ for C. vulgaris was found to be 510 ?g L(-1). We showed that the algal cells were obviously depressed or shrunk in 300 and 600 ?g L(-1) AZ treatments by using the electron microscopy. Furthermore, 19, 75, and 300 ?g L(-1) AZ treatments decreased the soluble protein content and chlorophyll concentrations in C. vulgaris and altered the energy-photosynthesis-related mRNA expression levels in 48- and 96-h exposure periods. Simultaneously, our results showed that AZ could increase the total antioxidant capacity (T-AOC) level and compromise superoxide dismutase (SOD), peroxidase (POD), glutathione S transferase (GST), glutathione peroxidase (GPx) activities, and glutathione (GSH) content. These situations might render C. vulgaris more vulnerable to oxidative damage. Overall, the present study indicated that AZ might be toxic to the growth of C. vulgaris, affect energy-photosynthesis-related mRNA expressions, and induce reactive oxygen species (ROS) overproduction in C. vulgaris. PMID:25672875

  11. TGF-?1 induces apoptosis of bone marrow-derived mesenchymal stem cells via regulation of mitochondrial reactive oxygen species production

    PubMed Central

    ZHANG, FENXI; REN, TONGMING; WU, JUNFANG

    2015-01-01

    Bone marrow-derived mesenchymal stem cells (BMSCs) are the most promising seed cells in regenerative medicine. Our previous study demonstrated that transforming growth factor (TGF)-?1 induced BMSC senescence in vitro. Whether TGF-?1 affects the apoptosis of BMSCs has not been examined; therefore the aim of the present study was to investigate this effect. BMSCs were isolated from mouse bone marrow, and the third-passage cells were exposed to 0, 10 and 20 ng/ml TGF-?1 for 24 h. Cell proliferation was measured by MTT assay; apoptosis was assessed using DAPI staining; and the apoptotic signals Annexin V, B-cell lymphoma (Bcl)-2 and Bcl-2-associated X protein (Bax) were measured using western blotting. Mitochondrial reactive oxygen species (ROS) were measured by flow cytometry following staining with MitoSOX™ Red mitochondrial superoxide indicator. The MTT assay showed that 10 and 20 ng/ml TGF-?1 inhibited BMSC proliferation. DAPI staining demonstrated that 10 and 20 ng/ml TGF-?1 promoted BMSC apoptosis, which was further confirmed by a western blotting assay showing a significant increase in the pro-apoptotic signals Annexin V and Bax but a decrease in the anti-apoptotic signal Bcl-2. It was also found that TGF-?1 markedly increased the mitochondrial ROS levels in BMSCs. It is well known that mitochondrial ROS are strong stimulators of cell apoptosis. These findings indicate that TGF-?1 can induce BMSC apoptosis, and the mechanism may involve mitochondrial ROS generation.

  12. Formation of ferrihydrite and associated iron corrosion products in permeable reactive barriers of zero-valent iron

    NASA Technical Reports Server (NTRS)

    Furukawa, Yoko; Kim, Jin-Wook; Watkins, Janet; Wilkin, Richard T.

    2002-01-01

    Ferrihydrite, which is known to form in the presence of oxygen and to be stabilized by the adsorption of Si, PO4 and SO4, is ubiquitous in the fine-grained fractions of permeable reactive barrier (PRB) samples from the U.S. Coast Guard Support Center (Elizabeth City, NC) and the Denver Federal Center (Lakewood, CO) studied by high-resolution transmission electron microscopy and selected area electron diffraction. The concurrent energy-dispersive X-ray data indicate a strong association between ferrihydrite and metals such as Si, Ca, and Cr. Magnetite, green rust 1, aragonite, calcite, mackinawite, greigite and lepidocrocite were also present, indicative of a geochemical environment that is temporally and spatially heterogeneous. Whereas magnetite, which is known to form due to anaerobic Fe0 corrosion, passivates the Fe0 surface, ferrihydrite precipitation occurs away from the immediate Fe0 surface, forming small (<0.1 microm) discrete clusters. Consequently, Fe0-PRBs may remain effective for a longer period of time in slightly oxidized groundwater systems where ferrihydrite formation occurs compared to oxygen-depleted systems where magnetite passivation occurs. The ubiquitous presence of ferrihydrite suggests that the use of Fe0-PRBs may be extended to applications that require contaminant adsorption rather than, or in addition to, redox-promoted contaminant degradation.

  13. Groundwater dynamics in wetland soils control the production and transfer mechanisms of dissolved reactive phosphorus in an agricultural landscape

    NASA Astrophysics Data System (ADS)

    Dupas, Rémi; Gu, Sen; Gruau, Gérard; Gascuel-Odoux, Chantal

    2015-04-01

    Because of its high sorption affinity on soils solid phase, mitigation options to reduce diffuse P transfer usually focus on trapping particulate P forms delivered via surface flowpaths. Therefore, vegetated buffer zones placed between croplands and watercourses have been promoted worldwide, sometimes in wetland areas. To investigate the risk of such P trapping riparian wetlands (RWs) releasing dissolved P to rivers, we monitored molybdate reactive P (MRP) in the free soil solution of two RWs in an intensively farmed catchment. Two main mechanisms causing MRP release were identified in light of the geochemical and hydrological conditions in the RWs, controlled by groundwater dynamics. First, soil rewetting after the dry summer was associated with the presence of a pool of mobile P, limited in size. Its mobilization started under conditions of water saturation caused by groundwater uprise in RW organo-mineral soil horizons. Second, the establishment of anoxic conditions in the end of the winter caused reductive solubilization of Fe oxide-hydroxide, along with release of P. Comparison between sites revealed that the first MRP release occurred only in a RW with P enriched soils, whereas the second was recorded even in a RW with a low soil P status. Seasonal variations in MRP concentrations in the stream were synchronized with those in RW soils. Hence, enriched and/or periodically anoxic RWs can act as a key component of the P transfer continuum in agricultural landscapes by converting particulate P from croplands into MRP released to rivers.

  14. Reactive collisions of sulfur dioxide with molten carbonates

    PubMed Central

    Krebs, Thomas; Nathanson, Gilbert M.

    2010-01-01

    Molecular beam scattering experiments are used to investigate reactions of SO2 at the surface of a molten alkali carbonate eutectic at 683 K. We find that two-thirds of the SO2 molecules that thermalize at the surface of the melt are converted to gaseous CO2 via the reaction . The CO2 product is formed from SO2 in less than 10-6 s, implying that the reaction takes place in a shallow liquid region less than 100 ? deep. The reaction probability does not vary between 683 and 883 K, further implying a compensation between decreasing SO2 residence time in the near-interfacial region and increasing reactivity at higher temperatures. These results demonstrate the remarkable efficiency of SO2 ? CO2 conversion by molten carbonates, which appear to be much more reactive than dry calcium carbonate or wet slurries commonly used for flue gas desulfurization in coal-burning power plants. PMID:20133648

  15. Diffractive Dijet Production in Deep Inelastic Scattering and Photon-Hadron Collisions in the Color Glass Condensate

    E-print Network

    Altinoluk, Tolga; Beuf, Guillaume; Rezaeian, Amir H

    2015-01-01

    We study diffractive dijet production in deep inelastic scattering and real (and virtual) photon-hadron ($\\gamma^{(*)}$-h) collisions in the Color Glass Condensate formalism at leading order. We show that the diffractive dijet cross section is sensitive to the color-dipole orientation in the transverse plane, and is a good probe of possible correlations between the $q\\bar{q}$-dipole transverse separation vector $\\vec r$ and the dipole impact parameter $\\vec b$. We also investigate the diffractive dijet azimuthal angle correlations and $t$-distributions in $\\gamma^{(*)}$-h collisions and show that they are sensitive to gluon saturation effects in the small-$x$ region. In particular, we show that the $t$-distribution of diffractive dijet photo-production off a proton target exhibits a dip-type structure in the saturation region. This effect is similar to diffractive vector meson production. Besides, at variance with the inclusive case, the effect of saturation leads to stronger azimuthal correlations between th...

  16. Diffractive Dijet Production in Deep Inelastic Scattering and Photon-Hadron Collisions in the Color Glass Condensate

    E-print Network

    Tolga Altinoluk; Néstor Armesto; Guillaume Beuf; Amir H. Rezaeian

    2015-11-23

    We study diffractive dijet production in deep inelastic scattering and real (and virtual) photon-hadron ($\\gamma^{(*)}$-h) collisions in the Color Glass Condensate formalism at leading order. We show that the diffractive dijet cross section is sensitive to the color-dipole orientation in the transverse plane, and is a good probe of possible correlations between the $q\\bar{q}$-dipole transverse separation vector $\\vec r$ and the dipole impact parameter $\\vec b$. We also investigate the diffractive dijet azimuthal angle correlations and $t$-distributions in $\\gamma^{(*)}$-h collisions and show that they are sensitive to gluon saturation effects in the small-$x$ region. In particular, we show that the $t$-distribution of diffractive dijet photo-production off a proton target exhibits a dip-type structure in the saturation region. This effect is similar to diffractive vector meson production. Besides, at variance with the inclusive case, the effect of saturation leads to stronger azimuthal correlations between the jets.

  17. Protection of hypoglycemia-induced neuronal death by ?-hydroxybutyrate involves the preservation of energy levels and decreased production of reactive oxygen species.

    PubMed

    Julio-Amilpas, Alberto; Montiel, Teresa; Soto-Tinoco, Eva; Gerónimo-Olvera, Cristian; Massieu, Lourdes

    2015-05-01

    Glucose is the main energy substrate in brain but in certain circumstances such as prolonged fasting and the suckling period alternative substrates can be used such as the ketone bodies (KB), beta-hydroxybutyrate (BHB), and acetoacetate. It has been shown that KB prevent neuronal death induced during energy limiting conditions and excitotoxicity. The protective effect of KB has been mainly attributed to the improvement of mitochondrial function. In the present study, we have investigated the protective effect of D-BHB against neuronal death induced by severe noncoma hypoglycemia in the rat in vivo and by glucose deprivation (GD) in cortical cultures. Results show that systemic administration of D-BHB reduces reactive oxygen species (ROS) production in distinct cortical areas and subregions of the hippocampus and efficiently prevents neuronal death in the cortex of hypoglycemic animals. In vitro results show that D-BHB stimulates ATP production and reduces ROS levels, while the nonphysiologic isomer of BHB, L-BHB, has no effect on energy production but reduces ROS levels. Data suggest that protection by BHB, not only results from its metabolic action but is also related to its capability to reduce ROS, rendering this KB as a suitable candidate for the treatment of ischemic and traumatic injury. PMID:25649993

  18. Forward jet production in deep inelastic ep scattering and low-x parton dynamics at HERA

    NASA Astrophysics Data System (ADS)

    ZEUS Collaboration; Chekanov, S.; Derrick, M.; Magill, S.; Miglioranzi, S.; Musgrave, B.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Pavel, N.; Yagües Molina, A. G.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; de Pasquale, S.; Giusti, P.; Iacobucci, G.; Margotti, A.; Montanari, A.; Nania, R.; Palmonari, F.; Pesci, A.; Polini, A.; Rinaldi, L.; Sartorelli, G.; Zichichi, A.; Aghuzumtsyan, G.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Kind, O.; Meyer, U.; Paul, E.; Rautenberg, J.; Renner, R.; Voss, K. C.; Wang, M.; Wlasenko, M.; Bailey, D. S.; Brook, N. H.; Cole, J. E.; Heath, G. P.; Namsoo, T.; Robins, S.; Capua, M.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Helbich, M.; Ning, Y.; Ren, Z.; Schmidke, W. B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Stopa, P.; Szuba, D.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; Kowal, A. M.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Szuba, J.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Borras, K.; Drews, G.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Gutsche, O.; Haas, T.; Hain, W.; Horn, C.; Kahle, B.; Kötz, U.; Kowalski, H.; Kramberger, G.; Lelas, D.; Lim, H.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Nguyen, C. N.; Notz, D.; Nuncio-Quiroz, A. E.; Raval, A.; Santamarta, R.; Schneekloth, U.; Stösslein, U.; Wolf, G.; Youngman, C.; Zeuner, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Genta, C.; Pelfer, P. G.; Bamberger, A.; Benen, A.; Karstens, F.; Dobur, D.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Ferrando, J.; Hamilton, J.; Hanlon, S.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Carli, T.; Gosau, T.; Holm, U.; Krumnack, N.; Lohrmann, E.; Milite, M.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Stonjek, S.; Wichmann, K.; Wick, K.; Ziegler, A.; Ziegler, Ar.; Collins-Tooth, C.; Foudas, C.; Fry, C.; Gonçalo, R.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; González, O.; Jimenez, M.; Labarga, L.; del Peso, J.; Terrón, J.; Zambrana, M.; Barbi, M.; Corriveau, F.; Liu, C.; Padhi, S.; Plamondon, M.; Stairs, D. G.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Danilov, P.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Katkov, I. I.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Liu, X.; Sutiak, J.; Coppola, N.; Grigorescu, G.; Grijpink, S.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Maddox, E.; Pellegrino, A.; Schagen, S.; Tiecke, H.; Vázquez, M.; Wiggers, L.; de Wolf, E.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Grzelak, G.; Gwenlan, C.; Kohno, T.; Patel, S.; Straub, P. B.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Ciesielski, R.; dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Heaphy, E. A.; Metlica, F.; Oh, B. Y.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Kananov, S.; Kreisel, A.; Levy, A.; Kuze, M.; Kagawa, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Matsuzawa, K.; Ota, O.; Ri, Y. D.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Koop, T.; Martin, J. F.; Mirea, A.; Butterworth, J. M.; Hall-Wilton, R.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Targett-Adams, C.; Wing, M.; Ciborowski, J.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Sztuk, J.; Tymieniecka, T.; Tyszkiewicz, A.; Ukleja, A.; Ukleja, J.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Lightwood, M. S.; Everett, A.; Kçira, D.; Lammers, S.; Li, L.; Reeder, D. D.; Rosin, M.; Ryan, P.; Savin, A. A.; Smith, W. H.; Dhawan, S.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Soares, M.; Standage, J.; Whyte, J.

    2006-01-01

    Differential inclusive jet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 38.7 pb-1. The jets have been identified using the k cluster algorithm in the longitudinally invariant inclusive mode in the laboratory frame; they have been selected with jet transverse energy, ETjet above 6 GeV and jet pseudorapidity, ?, between -1 and 3. Measurements of cross sections as functions of ETjet, Björken x and the photon virtuality, Q, are presented. Three phase-space regions have been selected in order to study parton dynamics from the most global to the most restrictive region of forward-going (close to the proton-beam direction) jets at low x, where the effects of BFKL evolution might be present. The measurements have been compared to the predictions of leading-logarithm parton-shower Monte Carlo models and fixed-order perturbative QCD calculations. In the forward region, O(?s1) QCD calculations underestimate the data up to an order of magnitude at low x. An improved description of the data in this region is obtained by including O(?s2) QCD corrections, which account for the lowest-order tˆ-channel gluon-exchange diagrams, highlighting the importance of such terms in the parton dynamics at low x.

  19. Forward jet production in deep inelastic ep scattering and low- x parton dynamics at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Miglioranzi, S.; Musgrave, B.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Pavel, N.; Yagües Molina, A. G.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Giusti, P.; Iacobucci, G.; Margotti, A.; Montanari, A.; Nania, R.; Palmonari, F.; Pesci, A.; Polini, A.; Rinaldi, L.; Sartorelli, G.; Zichichi, A.; Aghuzumtsyan, G.; Bartsch, D.; Brock, I.; Goers, S.; Hartmann, H.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Kind, O.; Meyer, U.; Paul, E.; Rautenberg, J.; Renner, R.; Voss, K. C.; Wang, M.; Wlasenko, M.; Bailey, D. S.; Brook, N. H.; Cole, J. E.; Heath, G. P.; Namsoo, T.; Robins, S.; Capua, M.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ma, K. J.; Helbich, M.; Ning, Y.; Ren, Z.; Schmidke, W. B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Stopa, P.; Szuba, D.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; Kowal, A. M.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Szuba, J.; Kota?ski, A.; S?omi?ski, W.; Adler, V.; Behrens, U.; Bloch, I.; Borras, K.; Drews, G.; Fourletova, J.; Geiser, A.; Gladkov, D.; Göttlicher, P.; Gutsche, O.; Haas, T.; Hain, W.; Horn, C.; Kahle, B.; Kötz, U.; Kowalski, H.; Kramberger, G.; Lelas, D.; Lim, H.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Nguyen, C. N.; Notz, D.; Nuncio-Quiroz, A. E.; Raval, A.; Santamarta, R.; Schneekloth, U.; Stösslein, U.; Wolf, G.; Youngman, C.; Zeuner, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Genta, C.; Pelfer, P. G.; Bamberger, A.; Benen, A.; Karstens, F.; Dobur, D.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Ferrando, J.; Hamilton, J.; Hanlon, S.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Carli, T.; Gosau, T.; Holm, U.; Krumnack, N.; Lohrmann, E.; Milite, M.; Salehi, H.; Schleper, P.; Schörner-Sadenius, T.; Stonjek, S.; Wichmann, K.; Wick, K.; Ziegler, A.; Ziegler, Ar.; Collins-Tooth, C.; Foudas, C.; Fry, C.; Gonçalo, R.; Long, K. R.; Tapper, A. D.; Kataoka, M.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; González, O.; Jimenez, M.; Labarga, L.; del Peso, J.; Terrón, J.; Zambrana, M.; Barbi, M.; Corriveau, F.; Liu, C.; Padhi, S.; Plamondon, M.; Stairs, D. G.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Danilov, P.; Dolgoshein, B. A.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Katkov, I. I.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Zotkin, S. A.; Abt, I.; Büttner, C.; Caldwell, A.; Liu, X.; Sutiak, J.; Coppola, N.; Grigorescu, G.; Grijpink, S.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Maddox, E.; Pellegrino, A.; Schagen, S.; Tiecke, H.; Vázquez, M.; Wiggers, L.; de Wolf, E.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper, A. M.; Cottrell, A.; Devenish, R. C. E.; Foster, B.; Grzelak, G.; Gwenlan, C.; Kohno, T.; Patel, S.; Straub, P. B.; Walczak, R.; Bellan, P.; Bertolin, A.; Brugnera, R.; Carlin, R.; Ciesielski, R.; Dal Corso, F.; Dusini, S.; Garfagnini, A.; Limentani, S.; Longhin, A.; Stanco, L.; Turcato, M.; Heaphy, E. A.; Metlica, F.; Oh, B. Y.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Hart, J. C.; Abramowicz, H.; Gabareen, A.; Kananov, S.; Kreisel, A.; Levy, A.; Kuze, M.; Kagawa, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Matsuzawa, K.; Ota, O.; Ri, Y. D.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Koop, T.; Martin, J. F.; Mirea, A.; Butterworth, J. M.; Hall-Wilton, R.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Targett-Adams, C.; Wing, M.; Ciborowski, J.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Sztuk, J.; Tymieniecka, T.; Tyszkiewicz, A.; Ukleja, A.; Ukleja, J.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Lightwood, M. S.; Everett, A.; Kçira, D.; Lammers, S.; Li, L.; Reeder, D. D.; Rosin, M.; Ryan, P.; Savin, A. A.; Smith, W. H.; Dhawan, S.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Soares, M.; Standage, J.; Whyte, J.; ZEUS Collaboration

    2006-01-01

    Differential inclusive jet cross sections in neutral current deep inelastic ep scattering have been measured with the ZEUS detector using an integrated luminosity of 38.7 pb-1. The jets have been identified using the kT cluster algorithm in the longitudinally invariant inclusive mode in the laboratory frame; they have been selected with jet transverse energy, ETjet above 6 GeV and jet pseudorapidity, ?jet, between -1 and 3. Measurements of cross sections as functions of ETjet, Björken x and the photon virtuality, Q2, are presented. Three phase-space regions have been selected in order to study parton dynamics from the most global to the most restrictive region of forward-going (close to the proton-beam direction) jets at low x, where the effects of BFKL evolution might be present. The measurements have been compared to the predictions of leading-logarithm parton-shower Monte Carlo models and fixed-order perturbative QCD calculations. In the forward region, O (?s1) QCD calculations underestimate the data up to an order of magnitude at low x. An improved description of the data in this region is obtained by including O (?s2) QCD corrections, which account for the lowest-order tˆ-channel gluon-exchange diagrams, highlighting the importance of such terms in the parton dynamics at low x.

  20. Leghemoglobin green derivatives with nitrated hemes evidence production of highly reactive nitrogen species during aging of legume nodules

    PubMed Central

    Navascués, Joaquín; Pérez-Rontomé, Carmen; Gay, Marina; Marcos, Manuel; Yang, Fei; Walker, F. Ann; Desbois, Alain; Abián, Joaquín; Becana, Manuel

    2012-01-01

    Globins constitute a superfamily of proteins widespread in all kingdoms of life, where they fulfill multiple functions, such as efficient O2 transport and modulation of nitric oxide bioactivity. In plants, the most abundant Hbs are the symbiotic leghemoglobins (Lbs) that scavenge O2 and facilitate its diffusion to the N2-fixing bacteroids in nodules. The biosynthesis of Lbs during nodule formation has been studied in detail, whereas little is known about the green derivatives of Lbs generated during nodule senescence. Here we characterize modified forms of Lbs, termed Lbam, Lbcm, and Lbdm, of soybean nodules. These green Lbs have identical globins to the parent red Lbs but their hemes are nitrated. By combining UV-visible, MS, NMR, and resonance Raman spectroscopies with reconstitution experiments of the apoprotein with protoheme or mesoheme, we show that the nitro group is on the 4-vinyl. In vitro nitration of Lba with excess nitrite produced several isomers of nitrated heme, one of which is identical to those found in vivo. The use of antioxidants, metal chelators, and heme ligands reveals that nitration is contingent upon the binding of nitrite to heme Fe, and that the reactive nitrogen species involved derives from nitrous acid and is most probably the nitronium cation. The identification of these green Lbs provides conclusive evidence that highly oxidizing and nitrating species are produced in nodules leading to nitrosative stress. These findings are consistent with a previous report showing that the modified Lbs are more abundant in senescing nodules and have aberrant O2 binding. PMID:22308405

  1. Leghemoglobin green derivatives with nitrated hemes evidence production of highly reactive nitrogen species during aging of legume nodules.

    PubMed

    Navascués, Joaquín; Pérez-Rontomé, Carmen; Gay, Marina; Marcos, Manuel; Yang, Fei; Walker, F Ann; Desbois, Alain; Abián, Joaquín; Becana, Manuel

    2012-02-14

    Globins constitute a superfamily of proteins widespread in all kingdoms of life, where they fulfill multiple functions, such as efficient O(2) transport and modulation of nitric oxide bioactivity. In plants, the most abundant Hbs are the symbiotic leghemoglobins (Lbs) that scavenge O(2) and facilitate its diffusion to the N(2)-fixing bacteroids in nodules. The biosynthesis of Lbs during nodule formation has been studied in detail, whereas little is known about the green derivatives of Lbs generated during nodule senescence. Here we characterize modified forms of Lbs, termed Lba(m), Lbc(m), and Lbd(m), of soybean nodules. These green Lbs have identical globins to the parent red Lbs but their hemes are nitrated. By combining UV-visible, MS, NMR, and resonance Raman spectroscopies with reconstitution experiments of the apoprotein with protoheme or mesoheme, we show that the nitro group is on the 4-vinyl. In vitro nitration of Lba with excess nitrite produced several isomers of nitrated heme, one of which is identical to those found in vivo. The use of antioxidants, metal chelators, and heme ligands reveals that nitration is contingent upon the binding of nitrite to heme Fe, and that the reactive nitrogen species involved derives from nitrous acid and is most probably the nitronium cation. The identification of these green Lbs provides conclusive evidence that highly oxidizing and nitrating species are produced in nodules leading to nitrosative stress. These findings are consistent with a previous report showing that the modified Lbs are more abundant in senescing nodules and have aberrant O(2) binding. PMID:22308405

  2. Antiplatelet Effect of Catechol Is Related to Inhibition of Cyclooxygenase, Reactive Oxygen Species, ERK/p38 Signaling and Thromboxane A2 Production

    PubMed Central

    Wang, Tong-Mei; Lin, Bor-Ru; Yeung, Sin-Yuet; Yeh, Chien-Yang; Cheng, Ru-Hsiu; Jeng, Jiiang-Huei

    2014-01-01

    Catechol (benzenediol) is present in plant-derived products, such as vegetables, fruits, coffee, tea, wine, areca nut and cigarette smoke. Because platelet dysfunction is a risk factor of cardiovascular diseases, including stroke, atherosclerosis and myocardial infarction, the purpose of this study was to evaluate the anti-platelet and anti-inflammatory effect of catechol and its mechanisms. The effects of catechol on cyclooxygenase (COX) activity, arachidonic acid (AA)-induced aggregation, thromboxane B2 (TXB2) production, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) production and extracellular signal-regulated kinase (ERK)/p38 phosphorylation were determined in rabbit platelets. In addition, its effect on IL-1?-induced prostaglandin E2 (PGE2) production by fibroblasts was determined. The ex vivo effect of catechol on platelet aggregation was also measured. Catechol (5-25 µM) suppressed AA-induced platelet aggregation and inhibited TXB2 production at concentrations of 0.5–5 µM; however, it showed little cytotoxicity and did not alter U46619-induced platelet aggregation. Catechol (10–50 µM) suppressed COX-1 activity by 29–44% and COX-2 activity by 29–50%. It also inhibited IL-1?-induced PGE2 production, but not COX-2 expression of fibroblasts. Moreover, catechol (1–10 µM) attenuated AA-induced ROS production in platelets and phorbol myristate acetate (PMA)-induced ROS production in human polymorphonuclear leukocytes. Exposure of platelets to catechol decreased AA-induced ERK and p38 phosphorylation. Finally, intravenous administration of catechol (2.5–5 µmole/mouse) attenuated ex vivo AA-induced platelet aggregation. These results suggest that catechol exhibited anti-platelet and anti-inflammatory effects, which were mediated by inhibition of COX, ROS and TXA2 production as well as ERK/p38 phosphorylation. The anti-platelet effect of catechol was confirmed by ex vivo analysis. Exposure to catechol may affect platelet function and thus cardiovascular health. PMID:25122505

  3. Antiplatelet effect of catechol is related to inhibition of cyclooxygenase, reactive oxygen species, ERK/p38 signaling and thromboxane A2 production.

    PubMed

    Chang, Mei-Chi; Chang, Hsiao-Hua; Wang, Tong-Mei; Chan, Chiu-Po; Lin, Bor-Ru; Yeung, Sin-Yuet; Yeh, Chien-Yang; Cheng, Ru-Hsiu; Jeng, Jiiang-Huei

    2014-01-01

    Catechol (benzenediol) is present in plant-derived products, such as vegetables, fruits, coffee, tea, wine, areca nut and cigarette smoke. Because platelet dysfunction is a risk factor of cardiovascular diseases, including stroke, atherosclerosis and myocardial infarction, the purpose of this study was to evaluate the anti-platelet and anti-inflammatory effect of catechol and its mechanisms. The effects of catechol on cyclooxygenase (COX) activity, arachidonic acid (AA)-induced aggregation, thromboxane B2 (TXB2) production, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) production and extracellular signal-regulated kinase (ERK)/p38 phosphorylation were determined in rabbit platelets. In addition, its effect on IL-1?-induced prostaglandin E2 (PGE2) production by fibroblasts was determined. The ex vivo effect of catechol on platelet aggregation was also measured. Catechol (5-25 µM) suppressed AA-induced platelet aggregation and inhibited TXB2 production at concentrations of 0.5-5 µM; however, it showed little cytotoxicity and did not alter U46619-induced platelet aggregation. Catechol (10-50 µM) suppressed COX-1 activity by 29-44% and COX-2 activity by 29-50%. It also inhibited IL-1?-induced PGE2 production, but not COX-2 expression of fibroblasts. Moreover, catechol (1-10 µM) attenuated AA-induced ROS production in platelets and phorbol myristate acetate (PMA)-induced ROS production in human polymorphonuclear leukocytes. Exposure of platelets to catechol decreased AA-induced ERK and p38 phosphorylation. Finally, intravenous administration of catechol (2.5-5 µmole/mouse) attenuated ex vivo AA-induced platelet aggregation. These results suggest that catechol exhibited anti-platelet and anti-inflammatory effects, which were mediated by inhibition of COX, ROS and TXA2 production as well as ERK/p38 phosphorylation. The anti-platelet effect of catechol was confirmed by ex vivo analysis. Exposure to catechol may affect platelet function and thus cardiovascular health. PMID:25122505

  4. Climate and topographic controls on pasture production in a semiarid Mediterranean watershed with scattered tree cover

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, J.; Maneta, M. P.; Schnabel, S.

    2013-12-01

    Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatio-temporal variations of pasture production at the decadal to century scales over whole watersheds are poorly known. We used a physics-based, spatially-distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300 yr long synthetic daily climate dataset generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.

  5. Production of reactive oxygen species by freezing stress and the protective roles of antioxidant enzymes in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As one of the most severe environmental stresses, freezing stress can determine the distribution range of native flora in nature and severely reduce crop production. Many mechanisms have been proposed to explain the damage induced by freezing-thawing cycle, and oxidative stress caused by uncontrolla...

  6. Reactive scattering in the ultracold regime

    NASA Astrophysics Data System (ADS)

    Simbotin, I.; Côté, R.; Balakrishnan, N.; Dalgarno, A.

    2002-05-01

    We calculate reaction cross sections for D + H2 in the ultracold regime, using the abc program developed by Manolopoulos and his collaborators.(D. Skouteris, J. F. Castillo, D. E. Manolopoulos, Comput. Phys. Commun. 133), 128 (2000). As expected, the results we obtain are in agreement with Wigner's threshold law. For H_2(v=1), the total reaction cross section is smaller than the total quenching cross section, but for v>= 2 the situation is reversed. We analyze in detail the rovibrational distributions for several initial vibrational states of H_2. Preliminary results for Cl + H2 are also presented.

  7. Measurement of beauty production in deep inelastic scattering at HERA using decays into electrons

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Antonelli, S.; Antonioli, P.; Antonov, A.; Arneodo, M.; Aushev, V.; Aushev, Y.; Bachynska, O.; Bamberger, A.; Barakbaev, A. N.; Barbagli, G.; Bari, G.; Barreiro, F.; Bartosik, N.; Bartsch, D.; Basile, M.; Behnke, O.; Behr, J.; Behrens, U.; Bellagamba, L.; Bertolin, A.; Bhadra, S.; Bindi, M.; Blohm, C.; Bokhonov, V.; Bo?d, T.; Bolilyi, O.; Boos, E. G.; Borras, K.; Boscherini, D.; Bot, D.; Boutle, S. K.; Brock, I.; Brownson, E.; Brugnera, R.; Brümmer, N.; Bruni, A.; Bruni, G.; Brzozowska, B.; Bussey, P. J.; Butterworth, J. M.; Bylsma, B.; Caldwell, A.; Capua, M.; Carlin, R.; Catterall, C. D.; Chekanov, S.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; Cooper-Sarkar, A. M.; Coppola, N.; Corradi, M.; Corriveau, F.; Costa, M.; D'Agostini, G.; Dal Corso, F.; del Peso, J.; Dementiev, R. K.; De Pasquale, S.; Derrick, M.; Devenish, R. C. E.; Dobur, D.; Dolgoshein, B. A.; Dolinska, G.; Doyle, A. T.; Drugakov, V.; Durkin, L. S.; Dusini, S.; Eisenberg, Y.; Ermolov, P. F.; Eskreys, A.; Fang, S.; Fazio, S.; Ferrando, J.; Ferrero, M. I.; Figiel, J.; Forrest, M.; Foster, B.; Fourletov, S.; Gach, G.; Galas, A.; Gallo, E.; Garfagnini, A.; Geiser, A.; Gialas, I.; Gladilin, L. K.; Gladkov, D.; Glasman, C.; Gogota, O.; Golubkov, Y. A.; Göttlicher, P.; Grabowska-Bo?d, I.; Grebenyuk, J.; Gregor, I.; Grigorescu, G.; Grzelak, G.; Gueta, O.; Gwenlan, C.; Haas, T.; Hain, W.; Hamatsu, R.; Hart, J. C.; Hartmann, H.; Hartner, G.; Hilger, E.; Hochman, D.; Hori, R.; Horton, K.; Hüttmann, A.; Iacobucci, G.; Ibrahim, Z. A.; Iga, Y.; Ingbir, R.; Ishitsuka, M.; Jakob, H.-P.; Januschek, F.; Jimenez, M.; Jones, T. W.; Jüngst, M.; Kadenko, I.; Kahle, B.; Kamaluddin, B.; Kananov, S.; Kanno, T.; Karshon, U.; Karstens, F.; Katkov, I. I.; Kaur, M.; Kaur, P.; Keramidas, A.; Khein, L. A.; Kim, J. Y.; Kisielewska, D.; Kitamura, S.; Klanner, R.; Klein, U.; Koffeman, E.; Kooijman, P.; Korol, I.; Korzhavina, I. A.; Kota?ski, A.; Kötz, U.; Kowalski, H.; Kulinski, P.; Kuprash, O.; Kuze, M.; Lee, A.; Levchenko, B. B.; Levy, A.; Libov, V.; Limentani, S.; Ling, T. Y.; Lisovyi, M.; Lobodzinska, E.; Lohmann, W.; Löhr, B.; Lohrmann, E.; Loizides, J. H.; Long, K. R.; Longhin, A.; Lontkovskyi, D.; Lukina, O. Y.; ?u?niak, P.; Maeda, J.; Magill, S.; Makarenko, I.; Malka, J.; Mankel, R.; Margotti, A.; Marini, G.; Martin, J. F.; Mastroberardino, A.; Mattingly, M. C. K.; Melzer-Pellmann, I.-A.; Mergelmeyer, S.; Miglioranzi, S.; Mohamad Idris, F.; Monaco, V.; Montanari, A.; Morris, J. D.; Mujkic, K.; Musgrave, B.; Nagano, K.; Namsoo, T.; Nania, R.; Nicholass, D.; Nigro, A.; Ning, Y.; Noor, U.; Notz, D.; Nowak, R. J.; Nuncio-Quiroz, A. E.; Oh, B. Y.; Okazaki, N.; Oliver, K.; Olkiewicz, K.; Onishchuk, Y.; Papageorgiu, K.; Parenti, A.; Paul, E.; Pawlak, J. M.; Pawlik, B.; Pelfer, P. G.; Pellegrino, A.; Perlanski, W.; Perrey, H.; Piotrzkowski, K.; Plucinski, P.; Pokrovskiy, N. S.; Polini, A.; Proskuryakov, A. S.; Przybycie?, M.; Raval, A.; Reeder, D. D.; Reisert, B.; Ren, Z.; Repond, J.; Ri, Y. D.; Robertson, A.; Roloff, P.; Ron, E.; Rubinsky, I.; Ruspa, M.; Sacchi, R.; Salii, A.; Samson, U.; Sartorelli, G.; Savin, A. A.; Saxon, D. H.; Schioppa, M.; Schlenstedt, S.; Schleper, P.; Schmidke, W. B.; Schneekloth, U.; Schönberg, V.; Schörner-Sadenius, T.; Schwartz, J.; Sciulli, F.; Shcheglova, L. M.; Shehzadi, R.; Shimizu, S.; Singh, I.; Skillicorn, I. O.; S?omi?ski, W.; Smith, W. H.; Sola, V.; Solano, A.; Son, D.; Sosnovtsev, V.; Spiridonov, A.; Stadie, H.; Stanco, L.; Stern, A.; Stewart, T. P.; Stifutkin, A.; Stopa, P.; Suchkov, S.; Susinno, G.; Suszycki, L.; Sztuk-Dambietz, J.; Szuba, D.; Szuba, J.; Tapper, A. D.; Tassi, E.; Terrón, J.; Theedt, T.; Tiecke, H.; Tokushuku, K.; Tomalak, O.; Tomaszewska, J.; Tsurugai, T.; Turcato, M.; Tymieniecka, T.; Uribe-Estrada, C.; Vázquez, M.; Verbytskyi, A.; Viazlo, O.; Vlasov, N. N.; Volynets, O.; Walczak, R.; Wan Abdullah, W. A. T.; Whitmore, J. J.; Whyte, J.; Wiggers, L.; Wing, M.; Wlasenko, M.; Wolf, G.; Wolfe, H.; Wrona, K.; Yagües-Molina, A. G.; Yamada, S.; Yamazaki, Y.; Yoshida, R.; Youngman, C.; ?arnecki, A. F.; Zawiejski, L.; Zenaiev, O.; Zeuner, W.; Zhautykov, B. O.; Zhmak, N.; Zhou, C.; Zichichi, A.; Zolko, M.; Zotkin, D. S.; Zulkapli, Z.

    2011-02-01

    The production of beauty quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared Q 2>10 GeV2, using an integrated luminosity of 363 pb-1. The beauty events were identified using electrons from semileptonic b decays with a transverse momentum 0.9 < pTe < 8 GeV and pseudorapidity | ? e |<1.5. Cross sections for beauty production were measured and compared with next-to-leading-order QCD calculations. The beauty contribution to the proton structure function F 2 was extracted from the double-differential cross section as a function of Bjorken- x and Q 2.

  8. Measurement of beauty production in deep inelastic scattering at HERA using decays into electrons

    E-print Network

    ZEUS collaboration; H. Abramowicz; I. Abt; L. Adamczyk; M. Adamus; R. Aggarwal; S. Antonelli; P. Antonioli; A. Antonov; M. Arneodo; V. Aushev; Y. Aushev; O. Bachynska; A. Bamberger; A. N. Barakbaev; G. Barbagli; G. Bari; F. Barreiro; N. Bartosik; D. Bartsch; M. Basile; O. Behnke; J. Behr; U. Behrens; L. Bellagamba; A. Bertolin; S. Bhadra; M. Bindi; C. Blohm; V. Bokhonov; T. Bo?d; O. Bolilyi; E. G. Boos; K. Borras; D. Boscherini; D. Bot; S. K. Boutle; I. Brock; E. Brownson; R. Brugnera; N. Brümmer; A. Bruni; G. Bruni; B. Brzozowska; P. J. Bussey; J. M. Butterworth; B. Bylsma; A. Caldwell; M. Capua; R. Carlin; C. D. Catterall; S. Chekanov; J. Chwastowski; J. Ciborowski; R. Ciesielski; L. Cifarelli; F. Cindolo; A. Contin; A. M. Cooper-Sarkar; N. Coppola; M. Corradi; F. Corriveau; M. Costa; G. D'Agostini; F. Dal Corso; J. del Peso; R. K. Dementiev; S. De Pasquale; M. Derrick; R. C. E. Devenish; D. Dobur; B. A. Dolgoshein; G. Dolinska; A. T. Doyle; V. Drugakov; L. S. Durkin; S. Dusini; Y. Eisenberg; P. F. Ermolov; A. Eskreys; S. Fang; S. Fazio; J. Ferrando; M. I. Ferrero; J. Figiel; M. Forrest; B. Foster; S. Fourletov; G. Gach; A. Galas; E. Gallo; A. Garfagnini; A. Geiser; I. Gialas; L. K. Gladilin; D. Gladkov; C. Glasman; O. Gogota; Yu. A. Golubkov; P. Göttlicher; I. Grabowska-Bo?d; J. Grebenyuk; I. Gregor; G. Grigorescu; G. Grzelak; O. Gueta; C. Gwenlan; T. Haas; W. Hain; R. Hamatsu; J. C. Hart; H. Hartmann; G. Hartner; E. Hilger; D. Hochman; R. Hori; K. Horton; A. Hüttmann; G. Iacobucci; Z. A. Ibrahim; Y. Iga; R. Ingbir; M. Ishitsuka; H. -P. Jakob; F. Januschek; M. Jimenez; T. W. Jones; M. Jüngst; I. Kadenko; B. Kahle; B. Kamaluddin; S. Kananov; T. Kanno; U. Karshon; F. Karstens; I. I. Katkov; M. Kaur; P. Kaur; A. Keramidas; L. A. Khein; J. Y. Kim; D. Kisielewska; S. Kitamura; R. Klanner; U. Klein; E. Koffeman; P. Kooijman; Ie. Korol; I. A. Korzhavina; A. Kota?ski; U. Kötz; H. Kowalski; P. Kulinski; O. Kuprash; M. Kuze; A. Lee; B. B. Levchenko; A. Levy; V. Libov; S. Limentani; T. Y. Ling; M. Lisovyi; E. Lobodzinska; W. Lohmann; B. Löhr; E. Lohrmann; J. H. Loizides; K. R. Long; A. Longhin; D. Lontkovskyi; O. Yu. Lukina; P. ?u?niak; J. Maeda; S. Magill; I. Makarenko; J. Malka; R. Mankel; A. Margotti; G. Marini; J. F. Martin; A. Mastroberardino; M. C. K. Mattingly; I. -A. Melzer-Pellmann; S. Mergelmeyer; S. Miglioranzi; F. Mohamad Idris; V. Monaco; A. Montanari; J. D. Morris; K. Mujkic; B. Musgrave; K. Nagano; T. Namsoo; R. Nania; D. Nicholass; A. Nigro; Y. Ning; U. Noor; D. Notz; R. J. Nowak; A. E. Nuncio-Quiroz; B. Y. Oh; N. Okazaki; K. Oliver; K. Olkiewicz; Yu. Onishchuk; K. Papageorgiu; A. Parenti; E. Paul; J. M. Pawlak; B. Pawlik; P. G. Pelfer; A. Pellegrino; W. Perlanski; H. Perrey; K. Piotrzkowski; P. Plucinski; N. S. Pokrovskiy; A. Polini; A. S. Proskuryakov; M. Przybycie?; A. Raval; D. D. Reeder; B. Reisert; Z. Ren; J. Repond; Y. D. Ri; A. Robertson; P. Roloff; E. Ron; I. Rubinsky; M. Ruspa; R. Sacchi; A. Salii; U. Samson; G. Sartorelli; A. A. Savin; D. H. Saxon; M. Schioppa; S. Schlenstedt; P. Schleper; W. B. Schmidke; U. Schneekloth; V. Schönberg; T. Schörner-Sadenius; J. Schwartz; F. Sciulli; L. M. Shcheglova; R. Shehzadi; S. Shimizu; I. Singh; I. O. Skillicorn; W. S?omi?ski; W. H. Smith; V. Sola; A. Solano; D. Son; V. Sosnovtsev; A. Spiridonov; H. Stadie; L. Stanco; A. Stern; T. P. Stewart; A. Stifutkin; P. Stopa; S. Suchkov; G. Susinno; L. Suszycki; J. Sztuk-Dambietz; D. Szuba; J. Szuba; A. D. Tapper; E. Tassi; J. Terrón; T. Theedt; H. Tiecke; K. Tokushuku; O. Tomalak; J. Tomaszewska; T. Tsurugai; M. Turcato; T. Tymieniecka; C. Uribe-Estrada; M. Vázquez; A. Verbytskyi; O. Viazlo; N. N. Vlasov; O. Volynets; R. Walczak; W. A. T. Wan Abdullah; J. J. Whitmore; J. Whyte; L. Wiggers; M. Wing; M. Wlasenko; G. Wolf; H. Wolfe; K. Wrona; A. G. Yagües-Molina; S. Yamada; Y. Yamazaki; R. Yoshida; C. Youngman; A. F. ?arnecki; L. Zawiejski; O. Zenaiev; W. Zeuner; B. O. Zhautykov; N. Zhmak; C. Zhou; A. Zichichi; M. Zolko; D. S. Zotkin; Z. Zulkapli

    2011-03-10

    The production of beauty quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared Q^2 > 10 GeV^2, using an integrated luminosity of 363 pb^{-1}. The beauty events were identified using electrons from semileptonic b decays with a transverse momentum 0.9 < p_T^e < 8 GeV and pseudorapidity |eta^e| < 1.5. Cross sections for beauty production were measured and compared with next-to-leading-order QCD calculations. The beauty contribution to the proton structure function F_2 was extracted from the double-differential cross section as a function of Bjorken-x and Q^2.

  9. Heavy Majorana Neutrinos in Dilepton Production in Deep-Inelastic Lepton-Proton Scattering

    SciTech Connect

    Ali, A.; Borisov, A.V.; Zhuridov, D.V.

    2005-12-01

    The cross section for the production of pairs of likely charged leptons in the deep-inelastic processes e{sup +}p {yields} {nu}-bar{sub e}l{sup +}l{sup '+}X (l, l{sup '} = e, {mu}, {tau}) induced by the exchange of heavy Majorana neutrinos is calculated. The effect of interference between different neutrino mass eigenstates is studied. The possibilities for observing this effect at future lepton-proton colliders are considered.

  10. Teaching the fundamentals of electron transfer reactions in mitochondria and the production and detection of reactive oxygen species

    PubMed Central

    Mailloux, Ryan J.

    2015-01-01

    Mitochondria fulfill a number of biological functions which inherently depend on ATP and O2?•/H2O2 production. Both ATP and O2?•/H2O2 are generated by electron transfer reactions. ATP is the product of oxidative phosphorylation whereas O2?• is generated by singlet electron reduction of di-oxygen (O2). O2?• is then rapidly dismutated by superoxide dismutase (SOD) producing H2O2. O2?•/H2O2 were once viewed as unfortunately by-products of aerobic respiration. This characterization is fitting considering over production of O2?•/H2O2 by mitochondria is associated with range of pathological conditions and aging. However, O2?•/H2O2 are only dangerous in large quantities. If produced in a controlled fashion and maintained at a low concentration, cells can benefit greatly from the redox properties of O2?•/H2O2. Indeed, low rates of O2?•/H2O2 production are required for intrinsic mitochondrial signaling (e.g. modulation of mitochondrial processes) and communication with the rest of the cell. O2?•/H2O2 levels are kept in check by anti-oxidant defense systems that sequester O2?•/H2O2 with extreme efficiency. Given the importance of O2?•/H2O2 in cellular function, it is imperative to consider how mitochondria produce O2?•/H2O2 and how O2?•/H2O2 genesis is regulated in conjunction with fluctuations in nutritional and redox states. Here, I discuss the fundamentals of electron transfer reactions in mitochondria and emerging knowledge on the 11 potential sources of mitochondrial O2?•/H2O2 in tandem with their significance in contributing to overall O2?•/H2O2 emission in health and disease. The potential for classifying these different sites in isopotential groups, which is essentially defined by the redox properties of electron donator involved in O2?•/H2O2 production, as originally suggested by Brand and colleagues is also surveyed in detail. In addition, redox signaling mechanisms that control O2?•/H2O2 genesis from these sites are discussed. Finally, the current methodologies utilized for measuring O2?•/H2O2 in isolated mitochondria, cell culture and in vivo are reviewed. PMID:25744690

  11. Inhibition of Cytochrome P450 1A2-Mediated Metabolism and Production of Reactive Oxygen Species by Heme Oxygenase-1 in Rat Liver Microsomes

    PubMed Central

    Reed, James R.; Cawley, George F.; Backes, Wayne L.

    2011-01-01

    Heme oxygenase-1 (HO-1) is induced in most cell types by many forms of environmental stress and is believed to play a protective role in cells exposed to oxidative stress. Metabolism by cytochromes P450 (P450) is highly inefficient as the oxidation of substrate is associated with the production of varying proportions of hydrogen peroxide and/or superoxide. This study tests the hypothesis that heme oxygenase-1 (HO-1) plays a protective role against oxidative stress by competing with P450 for binding to the common redox partner, the NADPH P450 reductase (CPR) and in the process, diminishing P450 metabolism and the associated production of reactive oxygen species (ROS). Liver microsomes were isolated from uninduced rats and rats that were treated with cadmium and/or ?-napthoflavone (BNF) to induce HO-1 and/or CYP1A2. HO-1 induction was associated with slower rates of metabolism of the CYP1A2-specific substrate, 7-ethoxyresorufin. Furthermore, HO-1 induction also was associated with slower rates of hydrogen peroxide and hydroxyl radical production by microsomes from rats induced for CYP1A2. The inhibition associated with HO-1 induction was not dependent on the addition of heme to the microsomal incubations. The effects of HO-1 induction were less dramatic in the absence of substrate for CYP1A2, suggesting that the enzyme was more effective in inhibiting the CYP1A2-related activity than the CPR-related production of superoxide (that dismutates to form hydrogen peroxide). PMID:20942796

  12. Atmospheric reactivity of hydroxyl radicals with guaiacol (2-methoxyphenol), a biomass burning emitted compound: Secondary organic aerosol formation and gas-phase oxidation products

    NASA Astrophysics Data System (ADS)

    Lauraguais, Amélie; Coeur-Tourneur, Cécile; Cassez, Andy; Deboudt, Karine; Fourmentin, Marc; Choël, Marie

    2014-04-01

    Methoxyphenols are low molecular weight semi-volatile polar aromatic compounds produced from the pyrolysis of wood lignin. The reaction of guaiacol (2-methoxyphenol) with hydroxyl radicals has been studied in the LPCA simulation chamber at (294 ± 2) K, atmospheric pressure, low relative humidity (RH < 1%) and under high-NOx conditions using CH3ONO as OH source. The aerosol production was monitored using a SMPS (Scanning Mobility Particle Sizer); the SOA yields were in the range from 0.003 to 0.87 and the organic aerosol formation can be expressed by a one-product gas/particle partitioning absorption model. Transmission (TEM) and Scanning (SEM) Electron Microscopy observations were performed to characterize the physical state of SOA produced from the OH reaction with guaiacol; they display both liquid and solid particles (in an amorphous state). GC-FID (Gas Chromatography - Flame Ionization Detection) and GC-MS (Gas Chromatography - Mass Spectrometry) analysis show the formation of nitroguaiacol isomers as main oxidation products in the gas- and aerosol-phases. In the gas-phase, the formation yields were (10 ± 2) % for 4-nitroguaiacol (1-hydroxy-2-methoxy-4-nitrobenzene; 4-NG) and (6 ± 2) % for 3- or 6-nitroguaiacol (1-hydroxy-2-methoxy-3-nitrobenzene or 1-hydroxy-2-methoxy-6-nitrobenzene; 3/6-NG; the standards are not commercially available so both isomers cannot be distinguished) whereas in SOA their yield were much lower (?0.1%). To our knowledge, this work represents the first identification of nitroguaiacols as gaseous oxidation products of the OH reaction with guaiacol. As the reactivity of nitroguaiacols with atmospheric oxidants is probably low, we suggest using them as biomass burning emission gas tracers. The atmospheric implications of the guaiacol + OH reaction are also discussed.

  13. Label-free surface-enhanced Raman scattering strategy for rapid detection of penicilloic acid in milk products.

    PubMed

    Qi, Meihui; Huang, Xiaoyan; Zhou, Yujie; Zhang, Liying; Jin, Yang; Peng, Yan; Jiang, Huijun; Du, Shuhu

    2016-04-15

    A label-free surface-enhanced Raman scattering (SERS) strategy based on silver-coated gold nanoparticles (Au@Ag NPs) was developed for rapid detection of penicilloic acid (PA) in milk products. It has been demonstrated that core size and shell thickness of Au@Ag NPs are two critical variants affecting enhancement of Raman signals by coupling of two plasma resonance absorption. The Au@Ag NPs with 26-nm core and 9-nm Ag shell exhibit excellent Raman enhancement, in particular, upon the formation of hot spots through NPs aggregation induced by interaction between target molecules and Au@Ag NPs. Compared to the early studies limited to laboratory settings, our analytical approach is simple (without sample pretreatment), less time-consuming (within ?3min) and inexpensive. The limit of detection of PA is 3.00ppm, 3.00ppm and 4.00ppm in liquid milk, yogurt and milk powder, respectively. The label-free SERS technique offers a potential for the on-site monitoring of chemical contaminants in milk products. PMID:26617009

  14. DNAs from Brucella strains activate efficiently murine immune system with production of cytokines, reactive oxygen and nitrogen species.

    PubMed

    Tavakoli, Zahra; Ardestani, Sussan K; Lashkarbolouki, Taghi; Kariminia, Amina; Zahraei Salehi, Taghi; Tavassoli, Nasser

    2009-09-01

    Brucellosis is an infectious disease with high impact on innate immune responses which is induced partly by its DNA. In the present study the potential differences of wild type and patients isolates versus attenuated vaccine strains in terms of cytokines, ROS and NO induction on murine splenocytes and peritoneal macrophages were investigated. This panel varied in base composition and included DNA from B. abortus, B. melitensis, B.abortus strain S19 and melitensis strain Rev1, as attenuated live vaccine. Also we included Escherichia coli DNA, calf thymus DNA (a mammalian DNA), as controls. These DNA were evaluated for their ability to stimulate IL-12, TNF-alpha, IL-10, IFN-gamma and ROS production from spleenocytes as well as NO production from peritoneal macrophages. Spleen cells were cultured in 24 well at a concentration of 106 cells/ ml with subsequent addition of 10 microg/ml of Brucella or Ecoli DNAs. These cultures were incubated at 37 degrees C with 5% CO2 for 5 days. Supernatants were harvested and cytokines, ROS and NOx were evaluated. It was observed that TNF-alpha was induced in days 1,3,5 by all Brucella strains DNAs and E. coli DNA, IL-10 only was induced in day 1, IFN- gamma was induced only in day 5 and IL-12 not induced. ROS and NOx were produced by all strains; however, we observed higher production of NOx which were stimulated by DNA of B. melitensis. PMID:20124603

  15. ?-Glucan Induces Reactive Oxygen Species Production in Human Neutrophils to Improve the Killing of Candida albicans and Candida glabrata Isolates from Vulvovaginal Candidiasis

    PubMed Central

    Bonfim-Mendonça, Patricia de Souza; Ratti, Bianca Altrão; Godoy, Janine da Silva Ribeiro; Negri, Melyssa; de Lima, Nayara Cristina Alves; Fiorini, Adriana; Hatanaka, Elaine; Consolaro, Marcia Edilaine Lopes; de Oliveira Silva, Sueli; Svidzinski, Terezinha Inez Estivalet

    2014-01-01

    Vulvovaginal candidiasis (VVC) is among the most prevalent vaginal diseases. Candida albicans is still the most prevalent species associated with this pathology, however, the prevalence of other Candida species, such as C. glabrata, is increasing. The pathogenesis of these infections has been intensely studied, nevertheless, no consensus has been reached on the pathogenicity of VVC. In addition, inappropriate treatment or the presence of resistant strains can lead to RVVC (vulvovaginal candidiasis recurrent). Immunomodulation therapy studies have become increasingly promising, including with the ?-glucans. Thus, in the present study, we evaluated microbicidal activity, phagocytosis, intracellular oxidant species production, oxygen consumption, myeloperoxidase (MPO) activity, and the release of tumor necrosis factor ? (TNF-?), interleukin-8 (IL-8), IL-1?, and IL-1Ra in neutrophils previously treated or not with ?-glucan. In all of the assays, human neutrophils were challenged with C. albicans and C. glabrata isolated from vulvovaginal candidiasis. ?-glucan significantly increased oxidant species production, suggesting that ?-glucan may be an efficient immunomodulator that triggers an increase in the microbicidal response of neutrophils for both of the species isolated from vulvovaginal candidiasis. The effects of ?-glucan appeared to be mainly related to the activation of reactive oxygen species and modulation of cytokine release. PMID:25229476

  16. Ionizing radiation accelerates Drp1-dependent mitochondrial fission, which involves delayed mitochondrial reactive oxygen species production in normal human fibroblast-like cells

    SciTech Connect

    Kobashigawa, Shinko; Suzuki, Keiji; Yamashita, Shunichi

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer We report first time that ionizing radiation induces mitochondrial dynamic changes. Black-Right-Pointing-Pointer Radiation-induced mitochondrial fission was caused by Drp1 localization. Black-Right-Pointing-Pointer We found that radiation causes delayed ROS from mitochondria. Black-Right-Pointing-Pointer Down regulation of Drp1 rescued mitochondrial dysfunction after radiation exposure. -- Abstract: Ionizing radiation is known to increase intracellular level of reactive oxygen species (ROS) through mitochondrial dysfunction. Although it has been as a basis of radiation-induced genetic instability, the mechanism involving mitochondrial dysfunction remains unclear. Here we studied the dynamics of mitochondrial structure in normal human fibroblast like cells exposed to ionizing radiation. Delayed mitochondrial O{sub 2}{sup {center_dot}-} production was peaked 3 days after irradiation, which was coupled with accelerated mitochondrial fission. We found that radiation exposure accumulated dynamin-related protein 1 (Drp1) to mitochondria. Knocking down of Drp1 expression prevented radiation induced acceleration of mitochondrial fission. Furthermore, knockdown of Drp1 significantly suppressed delayed production of mitochondrial O{sub 2}{sup {center_dot}-}. Since the loss of mitochondrial membrane potential, which was induced by radiation was prevented in cells knocking down of Drp1 expression, indicating that the excessive mitochondrial fission was involved in delayed mitochondrial dysfunction after irradiation.

  17. Insights on the antitumor effects of kahweol on human breast cancer: Decreased survival and increased production of reactive oxygen species and cytotoxicity

    SciTech Connect

    Cárdenas, Casimiro; Quesada, Ana R.; Medina, Miguel Ángel

    2014-05-09

    Highlights: • Kahweol inhibits growth and attachment-independent proliferation of tumor cells. • Kahweol induces apoptosis in MDA-MB231 human breast cancer cells. • Kahweol-induced apoptosis involves caspase activation and cytochrome c release. • Kahweol does not protect against hydrogen peroxide cytotoxicity. • Kahweol increases hydrogen peroxide production by human breast cancer cells. - Abstract: The present study aims to identify the modulatory effects of kahweol, an antioxidant diterpene present in coffee beans, on a panel of human tumor cell lines. Kahweol inhibits tumor cell proliferation and clonogenicity and induces apoptosis in several kinds of human tumor cells. In the estrogen receptor-negative MDA-MB231 human breast cancer, the mentioned effects are accompanied by caspases 3/7 and 9 activation and cytochrome c release. On the other hand, kahweol increases the production of reactive oxygen species and their cytotoxicity in human breast cancer cells but not in normal cells. Taken together, our data suggest that kahweol is an antitumor compound with inhibitory effects on tumor cell growth and survival, especially against MDA-MB231 breast cancer cells.

  18. Functional Analysis of the Trichoderma harzianum nox1 Gene, Encoding an NADPH Oxidase, Relates Production of Reactive Oxygen Species to Specific Biocontrol Activity against Pythium ultimum?†

    PubMed Central

    Montero-Barrientos, M.; Hermosa, R.; Cardoza, R. E.; Gutiérrez, S.; Monte, E.

    2011-01-01

    The synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. The nox1 gene of Trichoderma harzianum was cloned, and its role in antagonism against phytopathogens was analyzed in nox1-overexpressed transformants. The increased levels of nox1 expression in these transformants were accompanied by an increase in ROS production during their direct confrontation with Pythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays against P. ultimum the nox1-overexpressed transformants were more effective than the wild type, but not in assays against Botrytis cinerea or Rhizoctonia solani. A transcriptomic analysis using a Trichoderma high-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-type T. harzianum and P. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of a nox1-overexpressed transformant with this pathogen. Our results show that nox1 is involved in T. harzianum ROS production and antagonism against P. ultimum. PMID:21421791

  19. Measurement of “pretzelosity” asymmetry of charged pion production in semi-inclusive deep inelastic scattering on a polarized He3 target

    DOE PAGESBeta

    Zhang, Y.; Qian, X.; Allada, K.; Dutta, C.; Huang, J.; Katich, J.; Wang, Y.; Aniol, K.; Annand, J. R. M.; Averett, T.; et al

    2014-11-24

    An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized ³He target was performed at Jefferson Lab in the kinematic region of 0.16 ± on 3He and on neutron pretzelosity asymmetries are consistent with zero within experimental uncertainties.

  20. A Tariff for Reactive Power

    SciTech Connect

    Kueck, John D; Kirby, Brendan J; Li, Fangxing; Tufon, Christopher; Isemonger, Alan

    2008-07-01

    Two kinds of power are required to operate an electric power system: real power, measured in watts, and reactive power, measured in volt-amperes reactive or VARs. Reactive power supply is one of a class of power system reliability services collectively known as ancillary services, and is essential for the reliable operation of the bulk power system. Reactive power flows when current leads or lags behind voltage. Typically, the current in a distribution system lags behind voltage because of inductive loads such as motors. Reactive power flow wastes energy and capacity and causes voltage droop. To correct lagging power flow, leading reactive power (current leading voltage) is supplied to bring the current into phase with voltage. When the current is in phase with voltage, there is a reduction in system losses, an increase in system capacity, and a rise in voltage. Reactive power can be supplied from either static or dynamic VAR sources. Static sources are typically transmission and distribution equipment, such as capacitors at substations, and their cost has historically been included in the revenue requirement of the transmission operator (TO), and recovered through cost-of-service rates. By contrast, dynamic sources are typically generators capable of producing variable levels of reactive power by automatically controlling the generator to regulate voltage. Transmission system devices such as synchronous condensers can also provide dynamic reactive power. A class of solid state devices (called flexible AC transmission system devices or FACTs) can provide dynamic reactive power. One specific device has the unfortunate name of static VAR compensator (SVC), where 'static' refers to the solid state nature of the device (it does not include rotating equipment) and not to the production of static reactive power. Dynamic sources at the distribution level, while more costly would be very useful in helping to regulate local voltage. Local voltage regulation would reduce system losses, increase circuit capacity, increase reliability, and improve efficiency. Reactive power is theoretically available from any inverter-based equipment such as photovoltaic (PV) systems, fuel cells, microturbines, and adjustable-speed drives. However, the installation is usually only economical if reactive power supply is considered during the design and construction phase. In this report, we find that if the inverters of PV systems or the generators of combined heat and power (CHP) systems were designed with capability to supply dynamic reactive power, they could do this quite economically. In fact, on an annualized basis, these inverters and generators may be able to supply dynamic reactive power for about $5 or $6 per kVAR. The savings from the local supply of dynamic reactive power would be in reduced losses, increased capacity, and decreased transmission congestion. The net savings are estimated to be about $7 per kVAR on an annualized basis for a hypothetical circuit. Thus the distribution company could economically purchase a dynamic reactive power service from customers for perhaps $6/kVAR. This practice would provide for better voltage regulation in the distribution system and would provide an alternate revenue source to help amortize the cost of PV and CHP installations. As distribution and transmission systems are operated under rising levels of stress, the value of local dynamic reactive supply is expected to grow. Also, large power inverters, in the range of 500 kW to 1 MW, are expected to decrease in cost as they become mass produced. This report provides one data point which shows that the local supply of dynamic reactive power is marginally profitable at present for a hypothetical circuit. We expect that the trends of growing power flow on the existing system and mass production of inverters for distributed energy devices will make the dynamic supply of reactive power from customers an integral component of economical and reliable system operation in the future.

  1. On the recuperation and production of electricity from scattered sources of energy

    NASA Astrophysics Data System (ADS)

    Berkovich, Simon

    2010-03-01

    Massive production of electricity from renewable sources encounters a number of complications. Thus, among the various ways of transforming solar radiation into electricity would be to heat compressed air as directly as possible for expansion. Employing a regular steam cycle is complicated and incurs high-maintenance costs. Stabilizing a delicate influx of energy from solar, winds, and wave sources is resolved similarly to computer processing with component of different productivities, namely with buffering and pipelining. Actually, the pipelining scheme for heating the air is somehow used to make the heating process more thermodynamically efficient. However, because of timing misbalance it may contribute to the temporal variations of the main working cycle. All these temporal variations problems can be handled by ``buffering'' scheme, in the way similar to processing of intensive information flows with relatively slow computers. Most effective embodiment of this scheme would be generating electricity from the surf waves as they do not suffer from intermittent interruptions. This can be done for storing and recuperation enhancement of energy by using liquid nitrogen.

  2. Production of reactive sintered nickel aluminide. Fifth quarterly technical progress report, February 22, 1993--May 22, 1993

    SciTech Connect

    Cooper, R.M.

    1993-06-01

    Effort over the past 3 months was directed at increasing manufacturing capacity (ball milling) and improving product quality. Orders for the powder have increased, mainly for plasma spray powders. NiAl is an excellent coat between a metal and a ceramic, and its use instead of cobalt should extending operating range for carbide tools. The feather phase in the sintered Ni{sub 3}Al was identified to be a Ni-rich phase nucleated on the grain boundaries with 10 wt % Al composition. The ductile to brittle temperature of powder extruded NiAl was found to be between 500 and 600 C, and shows a 50% elongation at 600 C.

  3. Reactive oxygen species (ROS) induced cytokine production and cytotoxicity of PAMAM dendrimers in J774A.1 cells

    SciTech Connect

    Naha, Pratap C.; Davoren, Maria; Lyng, Fiona M.; Byrne, Hugh J.

    2010-07-15

    The immunotoxicity of three generations of polyamidoamine (PAMAM) dendrimers (G-4, G-5 and G-6) was evaluated in mouse macrophage cells in vitro. Using the Alamar blue and MTT assays, a generation dependent cytotoxicity of the PAMAM dendrimers was found whereby G-6 > G-5 > G-4. The toxic response of the PAMAM dendrimers correlated well with the number of surface primary amino groups, with increasing number resulting in an increase in toxic response. An assessment of intracellular ROS generation by the PAMAM dendrimers was performed by measuring the increased fluorescence as a result of intracellular oxidation of Carboxy H{sub 2}DCFDA to DCF both quantitatively using plate reader and qualitatively by confocal laser scanning microscopy. The inflammatory mediators macrophage inflammatory protein-2 (MIP-2), tumour necrosis factor-{alpha} (TNF-{alpha}) and interleukin-6, (IL-6) were measured by the enzyme linked immunosorbant assay (ELISA) following exposure of mouse macrophage cells to PAMAM dendrimers. A generation dependent ROS and cytokine production was found, which correlated well with the cytotoxicological response and therefore number of surface amino groups. A clear time sequence of increased ROS generation (maximum at {approx} 4 h), TNF-{alpha} and IL-6 secretion (maximum at {approx} 24 h), MIP-2 levels and cell death ({approx} 72 h) was observed. The intracellular ROS generation and cytokine production induced cytotoxicity point towards the mechanistic pathway of cell death upon exposure to PAMAM dendrimers.

  4. Induction of necrosis and apoptosis to KB cancer cells by sanguinarine is associated with reactive oxygen species production and mitochondrial membrane depolarization

    SciTech Connect

    Chang, M.-C.; Chan, C.-P.; Wang, Y.-J.; Lee, P.-H.; Chen, L.-I; Tsai, Y.-L.; Lin, B.-R.; Wang, Y.-L.; Jeng, J.-H. . E-mail: huei@ha.mc.ntu.edu.tw

    2007-01-15

    Sanguinarine is a benzopheanthridine alkaloid present in the root of Sanguinaria canadensis L. and Chellidonium majus L. In this study, sanguinarine (2 and 3 {mu}M) exhibited cytotoxicity to KB cancer cells by decreasing MTT reduction to 83% and 52% of control after 24-h of exposure. Sanguinarine also inhibited the colony forming capacity (> 52-58%) and growth of KB cancer cells at concentrations higher than 0.5-1 {mu}M. Short-term exposure to sanguinarine (> 0.5 {mu}M) effectively suppressed the adhesion of KB cells to collagen and fibronectin (FN). Sanguinarine (2 and 3 {mu}M) induced evident apoptosis as indicated by an increase in sub-G0/G1 populations, which was detected after 6-h of exposure. Only a slight increase in cells arresting in S-phase and G2/M was noted. Induction of KB cell apoptosis and necrosis by sanguinarine (2 and 3 {mu}M) was further confirmed by Annexin V-PI dual staining flow cytometry and the presence of DNA fragmentation. The cytotoxicity by sanguinarine was accompanied by an increase in production of reactive oxygen species (ROS) and depolarization of mitochondrial membrane potential as indicated by single cell flow cytometric analysis of DCF and rhodamine fluorescence. NAC (1 and 3 mM) and catalase (2000 U/ml) prevented the sanguinarine-induced ROS production and cytotoxicity, whereas dimethylthiourea (DMT) showed no marked preventive effect. These results suggest that sanguinarine has anticarcinogenic properties with induction of ROS production and mitochondrial membrane depolarization, which mediate cancer cell death.

  5. Effects of Rosa laevigata Michx. extract on reactive oxygen species production and mitochondrial membrane potential in lens epithelial cells cultured under high glucose

    PubMed Central

    Liu, Yuefeng; Luo, Weimin; Luo, Xiangyu; Yong, Zhang; Zhong, Xiaodong

    2015-01-01

    This study was to investigate the effects of Rosa laevigata Michx. (RLM) extract on reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) in lens epithelial cells (LECs) cultured under high glucose. SRA01/04 cell models of diabetic cataract were established by high glucose culture, and these cells were administrated with RLM extract. Levels of ROS and MMP in SRA01/04 cells were detected with fluorescent probes. HO-1 expression level, Akt phosphorylation, and Nrf2 translocation were detected by Western blot. RLM treatment could exert protective effects on SRA01/04 cells under high glucose condition, decreasing the ROS production and elevating the MMP in these cells. Western blot analysis indicated that the expression level of HO-1 was significantly elevated in SRA01/04 cells after the RLM treatment. Moreover, when HO-1 was interfered with siRNA, the effects of RLM on the levels of ROS and MMP were diminished, indicating that HO-1 induction was necessary for the function of RLM. Furthermore, HO-1 inducing effects of RLM were mediated by the PI3K/Akt and Nrf2/ARE pathways. The effects would be abolished when either pathway was inhibited by pharmacological manipulation or siRNA silencing. RLM inhibits ROS production and elevates MMP, through the induction of HO-1 expression, in LECs under high glucose condition. The protective effects of RLM are mediated by the PI3K/Akt and Nrf2/ARE pathways. Our findings provide theoretic basis and experimental evidence for the application of RLM in the treatment of diabetic cataract. PMID:26629073

  6. Bone morphogenic protein 4 produced in endothelial cells by oscillatory shear stress induces monocyte adhesion by stimulating reactive oxygen species production from a nox1-based NADPH oxidase.

    PubMed

    Sorescu, George P; Song, Hannah; Tressel, Sarah L; Hwang, Jinah; Dikalov, Sergey; Smith, Debra A; Boyd, Nolan L; Platt, Manu O; Lassègue, Bernard; Griendling, Kathy K; Jo, Hanjoong

    2004-10-15

    Atherosclerosis is an inflammatory disease occurring preferentially in arterial regions exposed to disturbed flow conditions including oscillatory shear stress (OS). OS exposure induces endothelial expression of bone morphogenic protein 4 (BMP4), which in turn may activate intercellular adhesion molecule-1 (ICAM-1) expression and monocyte adhesion. OS is also known to induce monocyte adhesion by producing reactive oxygen species (ROS) from reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, raising the possibility that BMP4 may stimulate the inflammatory response by ROS-dependent mechanisms. Here we show that ROS scavengers blocked ICAM-1 expression and monocyte adhesion induced by BMP4 or OS in endothelial cells (ECs). Similar to OS, BMP4 stimulated H2O2 and O2- production in ECs. Next, we used ECs obtained from p47phox-/- mice (MAE-p47-/-), which do not produce ROS in response to OS, to determine the role of NADPH oxidases. Similar to OS, BMP4 failed to induce monocyte adhesion in MAE-p47-/-, but it was restored when the cells were transfected with p47phox plasmid. Moreover, OS-induced O2- production was blocked by noggin (a BMP antagonist), suggesting a role for BMP. Furthermore, OS increased gp91phox (nox2) and nox1 mRNA levels while decreasing nox4. In contrast, BMP4 induced nox1 mRNA expression, whereas nox2 and nox4 were decreased or not affected, respectively. Also, OS-induced monocyte adhesion was blocked by knocking down nox1 with the small interfering RNA (siRNA). Finally, BMP4 siRNA inhibited OS-induced ROS production and monocyte adhesion. Together, these results suggest that BMP4 produced in ECs by OS stimulates ROS release from the nox1-dependent NADPH oxidase leading to inflammation, a critical early atherogenic step. PMID:15388638

  7. Central role of endogenous Toll-like receptor-2 activation in regulating inflammation, reactive oxygen species production, and subsequent neointimal formation after vascular injury

    SciTech Connect

    Shishido, Tetsuro . E-mail: Tetsuro_Shishido@URMC.Rochester.edu; Nozaki, Naoki; Takahashi, Hiroki; Arimoto, Takanori; Niizeki, Takeshi; Koyama, Yo; Abe, Jun-ichi; Takeishi, Yasuchika; Kubota, Isao

    2006-07-14

    Background: It is now evident that inflammation after vascular injury has significant impact on the restenosis after revascularization procedures such as angioplasty, stenting, and bypass grafting. However, the mechanisms that regulate inflammation and repair after vascular injury are incompletely understood. Here, we report that vascular injury-mediated cytokine expression, reactive oxygen species (ROS) production, as well as subsequent neointimal formation requires Toll-like receptor-2 (TLR-2) mediated signaling pathway in vivo. Methods and results: Vascular injury was induced by cuff-placement around the femoral artery in non-transgenic littermates (NLC) and TLR-2 knockout (TLR-2KO) mice. After cuff-placement in NLC mice, expression of TLR-2 was significantly increased in both smooth muscle medial layer and adventitia. Interestingly, we found that inflammatory genes expression such as tumor necrosis factor-{alpha}, interleukin-1{beta} (IL-1{beta}), IL-6, and monocyte chemoattractant protein-1 were markedly decreased in TLR-2KO mice compared with NLC mice. In addition, ROS production after vascular injury was attenuated in TLR-2KO mice compared with NLC mice. Since we observed the significant role of endogenous TLR-2 activation in regulating inflammatory responses and ROS production after vascular injury, we determined whether inhibition of endogenous TLR-2 activation can inhibit neointimal proliferation after vascular injury. Neointimal hyperplasia was markedly suppressed in TLR-2KO mice compared with WT mice at both 2 and 4 weeks after vascular injury. Conclusions: These findings suggested that endogenous TLR-2 activation might play a central role in the regulation of vascular inflammation as well as subsequent neointimal formation in injured vessels.

  8. Intravenous Immunoglobulin Prevents Murine Antibody-Mediated Acute Lung Injury at the Level of Neutrophil Reactive Oxygen Species (ROS) Production

    PubMed Central

    Semple, John W.; Kim, Michael; Hou, Jing; McVey, Mark; Lee, Young Jin; Tabuchi, Arata; Kuebler, Wolfgang M.; Chai, Zhong-Wei; Lazarus, Alan H.

    2012-01-01

    Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated mortality that can occur with any type of transfusion and is thought to be primarily due to donor antibodies activating pulmonary neutrophils in recipients. Recently, a large prospective case controlled clinical study of cardiac surgery patients demonstrated that despite implementation of male donors, a high incidence of TRALI still occurred and suggested a need for additional interventions in susceptible patient populations. To examine if intravenous immunoglobulin (IVIg) may be effective, a murine model of antibody-mediated acute lung injury that approximates human TRALI was examined. When BALB/c mice were injected with the anti-major histocompatibility complex class I antibody 34-1-2s, mild shock (reduced rectal temperature) and respiratory distress (dyspnea) were observed and pre-treatment of the mice with 2 g/kg IVIg completely prevented these symptoms. To determine IVIg's usefulness to affect severe lung damage, SCID mice, previously shown to be hypersensitive to 34-1-2s were used. SCID mice treated with 34-1-2s underwent severe shock, lung damage (increased wet/dry ratios) and 40% mortality within 2 hours. Treatment with 2 g/kg IVIg 18 hours before 34-1-2s administration completely protected the mice from all adverse events. Treatment with IVIg after symptoms began also reduced lung damage and mortality. While the prophylactic IVIg administration did not affect 34-1-2s-induced pulmonary neutrophil accumulation, bone marrow-derived neutrophils from the IVIg-treated mice displayed no spontaneous ROS production nor could they be stimulated in vitro with fMLP or 34-1-2s. These results suggest that IVIg prevents murine antibody-mediated acute lung injury at the level of neutrophil ROS production and thus, alleviating tissue damage. PMID:22363629

  9. ESEEM of industrial silica-bearing powders: reactivity of defects during wet processing in the ceramics production

    NASA Astrophysics Data System (ADS)

    Romanelli, Maurizio; Di Benedetto, Francesco; Fornaciai, Gabriele; Innocenti, Massimo; Montegrossi, Giordano; Pardi, Luca A.; Zoleo, Alfonso; Capacci, Fabio

    2015-05-01

    A study is undertaken to ascertain whether changes in the speciation of inorganic radicals are occurring during the ceramic industrial production that involves abundant silica powders as raw material. Industrial dusts were sampled in two ceramic firms, immediately after the wet mixing stage, performed with the aid of a relevant pressure. The dusts were then characterised by means of X-ray diffraction, analysis of the trace elements through chemical methods, granulometry, continuous-wave electron paramagnetic resonance (EPR) and pulsed electron spin echo envelope modulation (ESEEM) spectroscopies. The results of the characterisation point to a relevant change in the speciation of the two samples; namely, a prevailing contribution due to an inorganic radical different from that pertaining to pure quartz is pointed out. The combined interpretation of EPR and ESEEM data suggests the attribution of the main paramagnetic contribution to the A-centre in kaolinite, a constituent that is added to pure quartz at the initial stage of the ceramic production. In one of the two samples, a second weak EPR signal is attributed to the quartz's hAl species. By taking into account the relative quantities of quartz and kaolinite mixed in the two samples, and the relative abundances of the two radical species, we propose that the partial or complete suppression of the hAl species in favour of the A-centre of kaolinite has occurred. Although this change is apparently fostered by the mixture between quartz and another radical-bearing raw material, kaolinite, the suppression of the hAl centre of quartz is ascribed to the role played by the pressure and the wet environment during the industrial mixing procedure. This suppression provides a net change of radical speciation associated with quartz, when this phase is in contact with workers' respiratory system.

  10. Reactive oxygen species generated by a heat shock protein (Hsp) inducing product contributes to Hsp70 production and Hsp70-mediated protective immunity in Artemia franciscana against pathogenic vibrios.

    PubMed

    Baruah, Kartik; Norouzitallab, Parisa; Linayati, Linayati; Sorgeloos, Patrick; Bossier, Peter

    2014-10-01

    The cytoprotective role of heat shock protein (Hsp70) described in a variety of animal disease models, including vibriosis in farmed aquatic animals, suggests that new protective strategies relying upon the use of compounds that selectively turn on Hsp genes could be developed. The product Tex-OE® (hereafter referred to as Hspi), an extract from the skin of the prickly pear fruit, Opuntia ficus indica, was previously shown to trigger Hsp70 synthesis in a non-stressful situation in a variety of animals, including in a gnotobiotically (germ-free) cultured brine shrimp Artemia franciscana model system. This model system offers great potential for carrying out high-throughput, live-animal screens of compounds that have health benefit effects. By using this model system, we aimed to disclose the underlying cause behind the induction of Hsp70 by Hspi in the shrimp host, and to determine whether the product affects the shrimp in inducing resistance towards pathogenic vibrios. We provide unequivocal evidences indicating that during the pretreatment period with Hspi, there is an initial release of reactive oxygen species (hydrogen peroxide and/or superoxide anion), generated by the added product, in the rearing water and associated with the host. The reactive molecules generated are the triggering factors responsible for causing Hsp70 induction within Artemia. We have also shown that Hspi acts prophylactically at an optimum dose regimen to confer protection against pathogenic vibrios. This salutary effect was associated with upregulation of two important immune genes, prophenoloxidase and transglutaminase of the innate immune system. These findings suggest that inducers of stress protein (e.g. Hsp70) are potentially important modulator of immune responses and might be exploited to confer protection to cultured shrimp against Vibrio infection. PMID:24950414

  11. Structure- and concentration-specific assessment of the physiological reactivity of ?-dicarbonyl glucose degradation products in peritoneal dialysis fluids.

    PubMed

    Distler, Leonie; Georgieva, Angelina; Kenkel, Isabell; Huppert, Jochen; Pischetsrieder, Monika

    2014-08-18

    In peritoneal dialysis (PD), glucose degradation products (GDPs), which are formed during heat sterilization of dialysis fluids, lead to structural and functional changes in the peritoneal membrane, which eventually result in the loss of its ultrafiltration capacity. To determine the molecular mechanisms behind these processes, the present study tested the influence of the six major ?-dicarbonyl GDPs in PD fluids, namely, glyoxal, methylglyoxal, 3-deoxyglucosone (3-DG), 3-deoxygalactosone (3-DGal), 3,4-dideoxyglucosone-3-ene (3,4-DGE), and glucosone with respect to their potential to impair the enzymatic activity of RNase A as well as their effects on cell viability. For comprehensive risk assessment, the ?-dicarbonyl GDPs were applied separately and in concentrations as present in conventional PD fluids. Thus, it was shown that after 5 days, glucosone impaired RNase A activity most distinctly (58% remaining activity, p < 0.001 compared to that of the control), followed by 3,4-DGE (62%, p < 0.001), 3-DGal (66%, p < 0.001), and 3-DG (76%, p < 0.01). Methylglyoxal and glyoxal caused weaker inactivation with significant effects only after 10 days of incubation (79%, 81%, p < 0.001). Profiling of the advanced glycation end products formed during the incubation of RNase A with methylglyoxal revealed predominant formation of the arginine modifications imidazolinone, CEA/dihydroxyimidazoline, and tetrahydropyrimidine at Arg10, Arg33, Arg39, and Arg85. Particularly, modification at Arg39 may severely affect the active site of the enzyme. Additionally, structure- and concentration-specific assessment of the cytotoxicity of the ?-dicarbonyl GDPs was performed. Although present at very low concentration, the cytotoxic effect of PD fluids after 2 days of incubation was exclusively caused by 3,4-DGE (14% cell viability, p < 0.001). After 4 days of incubation, 3-DGal (13% cell viability, p < 0.001), 3-DG (24%, p < 0.001), and, to a lower extent, glyoxal and methylglyoxal (both 57%, p < 0.01) also reduced cell viability significantly. In conclusion, 3,4-DGE, 3-DGal, and glucosone appear to be the most relevant parameters for the biocompatibility of PD fluids. PMID:25033248

  12. Acupuncture elicits neuroprotective effect by inhibiting NAPDH oxidase-mediated reactive oxygen species production in cerebral ischaemia.

    PubMed

    Shi, Guang-Xia; Wang, Xue-Rui; Yan, Chao-Qun; He, Tian; Yang, Jing-Wen; Zeng, Xiang-Hong; Xu, Qian; Zhu, Wen; Du, Si-Qi; Liu, Cun-Zhi

    2015-01-01

    In the current study, we aimed to investigate whether NADPH oxidase, a major ROS-producing enzyme, was involved in the antioxidant effect of acupuncture on cognitive impairment after cerebral ischaemia. The cognitive function, infract size, neuron cell loss, level of superoxide anion and expression of NADPH oxidase subunit in hippocampus of two-vessel occlusion (2VO) rats were determined after 2-week acupuncture. Furthermore, the cognitive function and production of O2(-) were determined in the presence and absence of NADPH oxidase agonist (TBCA) and antagonist (Apocynin). The effect of acupuncture on cognitive function after cerebral ischaemia in gp91phox-KO mice was evaluated by Morris water maze. Acupuncture reduced infarct size, attenuated overproduction of O2(-), and reversed consequential cognitive impairment and neuron cell loss in 2VO rats. The elevations of gp91phox and p47phox after 2VO were significantly decreased after acupuncture treatment. However, no differences of gp91phox mRNA were found among any experimental groups. Furthermore, these beneficial effects were reversed by TBCA, whereas apocynin mimicked the effect of acupuncture by improving cognitive function and decreasing O2(-) generation. Acupuncture failed to improve the memory impairment in gp91phox KO mice. Full function of the NADPH oxidase enzyme plays an important role in neuroprotective effects against cognitive impairment via inhibition of NAPDH oxidase-mediated oxidative stress. PMID:26656460

  13. Acupuncture elicits neuroprotective effect by inhibiting NAPDH oxidase-mediated reactive oxygen species production in cerebral ischaemia

    PubMed Central

    Shi, Guang-Xia; Wang, Xue-Rui; Yan, Chao-Qun; He, Tian; Yang, Jing-Wen; Zeng, Xiang-Hong; Xu, Qian; Zhu, Wen; Du, Si-Qi; Liu, Cun-Zhi

    2015-01-01

    In the current study, we aimed to investigate whether NADPH oxidase, a major ROS-producing enzyme, was involved in the antioxidant effect of acupuncture on cognitive impairment after cerebral ischaemia. The cognitive function, infract size, neuron cell loss, level of superoxide anion and expression of NADPH oxidase subunit in hippocampus of two-vessel occlusion (2VO) rats were determined after 2-week acupuncture. Furthermore, the cognitive function and production of O2? were determined in the presence and absence of NADPH oxidase agonist (TBCA) and antagonist (Apocynin). The effect of acupuncture on cognitive function after cerebral ischaemia in gp91phox-KO mice was evaluated by Morris water maze. Acupuncture reduced infarct size, attenuated overproduction of O2?, and reversed consequential cognitive impairment and neuron cell loss in 2VO rats. The elevations of gp91phox and p47phox after 2VO were significantly decreased after acupuncture treatment. However, no differences of gp91phox mRNA were found among any experimental groups. Furthermore, these beneficial effects were reversed by TBCA, whereas apocynin mimicked the effect of acupuncture by improving cognitive function and decreasing O2? generation. Acupuncture failed to improve the memory impairment in gp91phox KO mice. Full function of the NADPH oxidase enzyme plays an important role in neuroprotective effects against cognitive impairment via inhibition of NAPDH oxidase-mediated oxidative stress. PMID:26656460

  14. The 'reactive

    NASA Astrophysics Data System (ADS)

    Battista Piccardo, Giovanni; Guarnieri, Luisa

    2010-05-01

    The Ligurian ophiolitic peridotites [South Lanzo, Erro-Tobbio, Internal Ligurides and Corsica] are characterized by the abundance of spinel(Sp) peridotites showing depleted compositions and ranging from Cpx-poor Sp lherzolites to Sp harzburgites. They were recognized in the last decades as refractory residua by MORB-forming partial melting of the asthenosphere, and were similar to abyssal peridotites. Recent structural and compositional studies promoted a better understanding of their structural and compositional features and their genetic processes. In the field these depleted peridotites replace with primary contacts pyroxenite-bearing fertile Sp lherzolites that have been recognized as sub-continental lithospheric mantle. Field relationships evidence that decametric-hectometric bodies of pristine pyroxenite-veined lithospheric Sp lherzolites are preserved as structural remnants within the km-scale masses of depleted peridotites. The depleted peridotites show coarse-grained recrystallized textures and reaction micro-structures indicating pyroxene dissolution and olivine precipitation that have been considered as records of melt/peridotite interaction during reactive diffuse porous flow of undersaturated melts. They show, moreover, contrasting bulk and mineral chemistries that cannot be produced by simple partial melting and melt extraction. In particular, their bulk compositions are depleted in SiO2 and enriched in FeO with respect to refractory residua after any kind of partial melting, as calculated by Niu (1997), indicating that they cannot be formed by simple partial melting and melt extraction processes. Moreover, TiO2 content in Sp is usually significantly higher (up to 0.8-1.0 wt%) than typical TiO2 contents of spinels (usually < 0.1-0.2 wt %) in fertile mantle peridotites and melting refractory residua, indicating that spinel attained element equilibration with a Ti-bearing basaltic melt. The depleted peridotites usually show strongly variable Cpx modal proportions (in range 2-10% vol. modal content) in the same peridotite body. Notwithstanding this strong Cpx modal variation, the Cpx C1-normalized REE patterns are closely similar, at the scale of the same massif. Cpx does not show progressive trace element depletion/fractionation concordantly with progressive decrease of the Cpx content, as expected during progressive partial melting. Cpx shows both: 1) sinusoidal patterns enriched in the L-MREE and depleted in the HREE, and 2) strongly LREE fractionated patterns, almost flat in the MREE-HREE region. Type-1 Cpx sinusoidal REE patterns are consistent with trace element equilibration with melts which record transient geochemical gradients formed during melt-peridotite interaction under long time-integrated melt-rock ratios. Type-2 Cpx fractionated REE patterns are closely similar to those of Cpx that attained trace element equilibration with fractional melts with MORB affinity. The fractionated and sinusoidal Cpx REE patterns indicate that the depleted peridotites underwent melt-peridotite interaction under open system melt migration, both at high melt/rock ratios and long time-integrated melt-rock ratios. The compositional characteristics of the percolating melts in equilibrium with Cpx, assuming that mantle Cpx and percolating liquids attained trace element equilibration during melt-peridotite interaction, are quite similar to those of liquids produced by 4-7% fractional melting of a Sp-facies DM asthenospheric mantle source. In summary, the micro-structural features and the compositional characteristics indicate that their petrogenetic process is represented by melt/peridotite interaction via reactive diffuse porous flow percolation. They are closely similar to the Huinan harzburgite xenoliths (Xu et al., 2003) that show a secondary recrystallized texture and compositions that deviate from the partial melting trend of residual peridotites. They are considered "reactive" harzburgites likely resulted from basaltic melt-rock interaction (dissolving pyroxenes and precipitating olivine) at the expens

  15. Production of reactive oxygen species by phagocytic cells after exposure to glass wool and stone wool fibres - effect of fibre preincubation in aqueous solution.

    PubMed

    Zoller, T; Zeller, W J

    2000-04-01

    The potential of four man-made vitreous fibres (MMVFs) (glass wool Code A, stone wool Code G, HT-N and MMVF 21) and of two natural mineral fibres (crocidolite, erionite) to induce production of reactive oxygen species (ROS) by differentiated HL-60 cells (HL-60-M cells) was investigated by determination of luminol-enhanced chemiluminescence (CL). Quartz served as positive control. The same system was used to uncover possible influences of fibre preincubation in aqueous solutions on the ROS-generating potential. Following preincubation in unbuffered saline over about 4 weeks, Code A and G fibres showed decreased ROS-generating potential as compared to freshly suspended fibres. On the other hand, MMVF 21 and HT-N fibres as well as crocidolite and erionite showed no decreased CL after incubation in aqueous solutions. The observed decrease of the ROS-generating potential of Code A and G fibres after preincubation may be an expression of fibre surface alterations (leaching, initiation of dissolution) that influences the response of exposed phagocytic cells. After incubation of both fibres in buffered solutions at different pH values (5.0, 7.4) a reduced ROS-generating potential was still discernible as compared to freshly suspended fibres. PMID:10713463

  16. [Hyperoxia induces reactive oxygen species production and promotes SIRT1 nucleocytoplasmic shuttling of peripheral blood mononuclear cells in premature infants in vitro].

    PubMed

    Yang, Xi; Dong, Wenbin; Li, Qingping; Kang, Lan; Lei, Xiaoping; Zhang, Lianyu; Lu, Youying; Zhai, Xuesong

    2015-12-01

    Objective To explore the relationship between deacetylase sirtuin 1 (SIRT1) and reactive oxygen species (ROS) after oxygen therapy in the peripheral blood mononuclear cells (PBMCs) of the premature infants. Methods According to the fraction of inspired O2 (FiO2), premature infants diagnosed with respiratory distress syndrome (RDS) (gestational age <32 weeks), were divided into three groups: low dosage oxygen group (FiO2 <300 mL/L), moderate dosage oxygen group (FiO2; 300 mL/L-400 mL/L), high dosage oxygen group (FiO2 >400 mL/L). After 48 hours of oxygen treatment, PBMCs and serum were collected from the peripheral blood. Then the intracellular ROS level was detected by MitoSOX(TM) Red labeling combined with confocal laser scanning microscopy; the malondialdehyde (MDA) content in the serum was determined by the whole spectrum spectrophotometer; the SIRT1 localization was observed by immunofluorescence staining; and the SIRT1 levels in PBMCs were examined by Western blotting. Results With the increase of FiO2, the ROS, MDA content and the rate of SIRT1 nucleocytoplasmic shuttling of PBMCs gradually increased and SIRT1 protein expression was significantly lowered. Conclusion Hyperoxia induces ROS production in premature infants, promotes SIRT1 to cross from nucleus to cytoplasm, inhibits the resistant ability of SIRT1 to oxidative stress. PMID:26648302

  17. Effect of Penicillium mycotoxins on the cytokine gene expression, reactive oxygen species production, and phagocytosis of bovine macrophage (BoMacs) function.

    PubMed

    Oh, Se-Young; Mead, Philip J; Sharma, Bhawani S; Quinton, V Margaret; Boermans, Herman J; Smith, Trevor K; Swamy, H V L N; Karrow, Niel A

    2015-12-25

    Bovine macrophages (BoMacs) were exposed to the following Penicillium mycotoxins (PM): citrinin (CIT), ochratoxin A (OTA), patulin (PAT), mycophenolic acid (MPA) and penicillic acid (PA). PM exposure at the concentration that inhibits proliferation by 25% (IC25) differentially for 24h altered the gene expression of various cytokines. OTA significantly induced IL-1? expression (p<0.05), while the expression of IL-6 was suppressed (p<0.01). MPA significantly induced the expression of IL-1? (p<0.05) and reduced the expression of IL-12? (p<0.01) and IL-10 (p<0.01). PAT significantly suppressed the expression of IL-23 (p<0.01), IL-10 (p<0.05) and TGF-? (p<0.05). Some PMs also affected reactive oxygen species (ROS) and phagocytosis of Mycobacterium avium ssp. Paratuberculosis (MAP) at higher concentrations. PAT and PA for example, significantly decreased the percent phagocytosis of MAP at 5.0 (p<0.01) and 15.6?M (p<0.01), respectively, but only PA significantly suppressed PAM-3-stimulated ROS production at 62.5 (p<0.05) and 250.0?M (p<0.01). OTA significantly increased the percent phagocytosis of MAP at 6.3 (p<0.05) and 12.5?M (p<0.01). These findings suggest that exposure to sub-lethal concentrations of PMs can affect macrophage function, which could affect immunoregulation and innate disease resistance to pathogens. PMID:26394380

  18. Reactivation of IgG-switched memory B cells by BCR-intrinsic signal amplification promotes IgG antibody production

    PubMed Central

    Lutz, Johannes; Dittmann, Kai; Bösl, Michael R; Winkler, Thomas H; Wienands, Jürgen; Engels, Niklas

    2015-01-01

    Secondary antibody responses are marked by faster kinetics, improved antibody affinity and a switch from IgM to other immunoglobulin isotypes, most notably IgG, compared with primary responses. These changes protect from reinfection and represent the principle of most vaccination strategies. Yet, the molecular mechanisms that underlie B-cell memory responses are unclear. Here we show, by inactivating the immunoglobulin tail tyrosine (ITT) signalling motif of membrane-bound IgG1 in the mouse, that the ITT facilitates maintenance and reactivation of IgG-switched memory B cells in vivo. The ITT motif equips IgG-switched cells with enhanced BCR signalling capacity, which supports their competitiveness in secondary immune reactions and drives the formation of IgG-secreting plasma cells even in the absence of T-cell help. Our results demonstrate that ITT signalling promotes the vigorous production of IgG antibodies and thus provide a molecular basis for humoral immunological memory.

  19. Jaridonin, a novel ent-kaurene diterpenoid from Isodon rubescens, inducing apoptosis via production of reactive oxygen species in esophageal cancer cells.

    PubMed

    Ma, Yong-Cheng; Ke, Yu; Zi, Xiaolin; Zhao, Wen; Shi, Xiao-Jing; Liu, Hong-Min

    2013-07-01

    Isodon rubescens, a Chinese herb, has been used as a folk, botanical medicine in China for inflammatory diseases and cancer treatment for many years. Recently, we isolated a new ent-kaurene diterpenoid, named Jaridonin, from Isodon rubescens. The chemical structure of Jaridonin was verified by infrared (IR), nuclear magnetic resonance (NMR), and mass spectrum (MS) data as well as X-ray spectra. Jaridonin potently reduced viabilities of several esophageal cancer cell lines, including EC109, EC9706 and EC1. Jaridonin treatment resulted in typical apoptotic morphological characteristics, increased the number of annexin V-positive staining cells, as well as caused a G2/M arrest in cell cycle progression. Furthermore, Jaridonin resulted in a significant loss of mitochondrial membrane potential, release of cytochrome c into the cytosol, and then activation of Caspase-9 and -3, leading to activation of the mitochondria mediated apoptosis. Furthermore, these effects of Jaridonin were accompanied by marked reactive oxygen species (ROS) production and increased expression of p53, p21(waf1/Cip1) and Bax, whereas two ROS scavengers, N-acetyl-L-cysteine (LNAC) and Vitamin C, significantly attenuated the effects of Jaridonin on the mitochondrial membrane potential, DNA damage, expression of p53 and p21(waf1/Cip1) and reduction of cell viabilities. Taken together, our results suggest that a natural ent-kaurenoid diterpenoid, Jaridonin, is a novel apoptosis inducer and deserves further investigation as a new chemotherapeutic strategy for patients with esophageal cancer. PMID:23597192

  20. Reactive Nitrogen, Ozone and Ozone Production in the Arctic Troposphere and the Impact of Stratosphere-Troposphere Exchange

    NASA Technical Reports Server (NTRS)

    Liang, Q.; Rodriquez, J. M.; Douglass, A. R.; Crawford, J. H.; Apel, E.; Bian, H.; Blake, D. R.; Brune, W.; Chin, M.; Colarco, P. R.; daSilva, A.; Diskin, G. S.; Duncan, B. N.; Huey, L. C.; Knapp, D. J.; Montzka, D. D.; Nielsen, J. E.; Olson, J. R.; Pawson, S.; Weinheimer, A. J.

    2011-01-01

    We analyze the aircraft observations obtained during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellite (ARCTAS) mission together with the GEOS-5 CO simulation to examine O3 and NOy in the Arctic and sub-Arctic region and their source attribution. Using a number of marker tracers and their probability density distributions, we distinguish various air masses from the background troposphere and examine their contribution to NOx, O3, and O3 production in the Arctic troposphere. The background Arctic troposphere has mean O3 of approximately 60 ppbv and NOx of approximately 25 pptv throughout spring and summer with CO decreases from approximately 145 ppbv in spring to approximately 100 ppbv in summer. These observed CO, NOx and O3 mixing ratios are not notably different from the values measured during the 1988 ABLE-3A and the 2002 TOPSE field campaigns despite the significant changes in the past two decades in processes that could have changed the Arctic tropospheric composition. Air masses associated with stratosphere-troposphere exchange are present throughout the mid and upper troposphere during spring and summer. These air masses with mean O3 concentration of 140-160 ppbv are the most important direct sources of O3 in the Arctic troposphere. In addition, air of stratospheric origin is the only notable driver of net O3 formation in the Arctic due to its sustainable high NOx (75 pptv in spring and 110 pptv in summer) and NOy (approximately 800 pptv in spring and approximately 1100 pptv in summer) levels. The ARCTAS measurements present observational evidence suggesting significant conversion of nitrogen from HNO3 to NOx and then to PAN (a net formation of approximately 120 pptv PAN) in summer when air of stratospheric origin is mixed with tropospheric background during stratosphere-to-troposphere transport. These findings imply that an adequate representation of stratospheric O3 and NOy input are essential in accurately simulating O3 and NOx photochemistry as well as the atmospheric budget of PAN in tropospheric chemistry transport models of the Arctic. Anthropogenic and biomass burning pollution plumes observed during ARCTAS show highly elevated hydrocarbons and NOy (mostly in the form of NOx and PAN), but do not contribute significantly to O3 in the Arctic troposphere except in some of the aged biomass burning plumes sampled during spring. Convection and/or lightning influences are negligible sources of O3 in the Arctic troposphere but can have significant impacts in the upper troposphere in the continental sub-Arctic during summer.

  1. Hispidin and related herbal compounds from Alpinia zerumbet inhibit both PAK1-dependent melanogenesis in melanocytes and reactive oxygen species (ROS) production in adipocytes.

    PubMed

    Be Tu, Pham Thi; Chompoo, Jamnian; Tawata, Shinkichi

    2015-06-01

    Recently several compounds from Okinawa plants including Alpinia zerumbet (alpinia) were shown to inhibit directly the oncogenic/ageing kinase PAK1 (p21-activated kinase 1). Furthermore, it was recently revealed that both PAK1 and PAK4 (p21-activated kinase 4) are equally essential for the melanogenesis in melanoma cells. Thus, in this study, we tested if several alpinia compounds inhibit the melanogenesis in melanoma (B16F10) cells, as well as the PAK1-dependent up-regulation of both reactive oxygen species (ROS) and nitric oxide (NO) in cultured adipocytes (3T3-L1) without any cytotoxicity. The effect of alpinia compounds on the melanogenesis was measured by both the melanin content and intracellular tyrosinase activity in melanoma cells treated with 3-isobutyl-1-methylxanthine (IBMX), a melanogenesis stimulating hormone. We found that (1E,3E,5E)-6-methoxyhexa-1,3,5-trien-1-yl)-2,5-dihydrofuran (MTD), 5,6-dehydrokawain (DK), labdadiene, hispidin and dihydro-5,6-dehydrokawain (DDK) at 50 ?g/mL reduced the melanin content by 63-79%. The MTD, DK and hispidin, at 50 ?g/mL, inhibited tyrosinase activity by 70-83% in melanoma cells. Among these compounds, labdadiene, MTD, (E)-2,2,3,3-Tetramethyl8-methylene-7-(oct-6-en-1-yl)octahydro-1H-quinolizine (TMOQ) and hispidin strongly inhibited the ROS production. Hispidin, labdadiene and MTD at 20 ?g/mL inhibited NO production by over 70%. These findings altogether suggest that some of these alpinia compounds could be potentially useful for the prevention or treatment of hyperpigmentation and obesity. PMID:26193942

  2. The production of reactive oxygen species is a universal action mechanism of Amphotericin B against pathogenic yeasts and contributes to the fungicidal effect of this drug.

    PubMed

    Mesa-Arango, Ana Cecilia; Trevijano-Contador, Nuria; Román, Elvira; Sánchez-Fresneda, Ruth; Casas, Celia; Herrero, Enrique; Argüelles, Juan Carlos; Pla, Jesús; Cuenca-Estrella, Manuel; Zaragoza, Oscar

    2014-11-01

    Amphotericin B (AMB) is an antifungal drug that binds to ergosterol and forms pores at the cell membrane, causing the loss of ions. In addition, AMB induces the accumulation of reactive oxygen species (ROS), and although these molecules have multiple deleterious effects on fungal cells, their specific role in the action mechanism of AMB remains unknown. In this work, we studied the role of ROS in the action mechanism of AMB. We determined the intracellular induction of ROS in 44 isolates of different pathogenic yeast species (Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, Candida krusei, Cryptococcus neoformans, and Cryptococcus gattii). We also characterized the production of ROS in AMB-resistant isolates. We found that AMB induces the formation of ROS in all the species tested. The inhibition of the mitochondrial respiratory chain by rotenone blocked the induction of ROS by AMB and provided protection from the killing action of the antifungal. Moreover, this phenomenon was absent in strains that displayed resistance to AMB. These strains showed an alteration in the respiration rate and mitochondrial membrane potential and also had higher catalase activity than that of the AMB-susceptible strains. Consistently, AMB failed to induce protein carbonylation in the resistant strains. Our data demonstrate that the production of ROS by AMB is a universal and important action mechanism that is correlated with the fungicidal effect and might explain the low rate of resistance to the molecule. Finally, these data provide an opportunity to design new strategies to improve the efficacy of this antifungal. PMID:25155595

  3. The Production of Reactive Oxygen Species Is a Universal Action Mechanism of Amphotericin B against Pathogenic Yeasts and Contributes to the Fungicidal Effect of This Drug

    PubMed Central

    Mesa-Arango, Ana Cecilia; Trevijano-Contador, Nuria; Román, Elvira; Sánchez-Fresneda, Ruth; Casas, Celia; Herrero, Enrique; Argüelles, Juan Carlos; Pla, Jesús; Cuenca-Estrella, Manuel

    2014-01-01

    Amphotericin B (AMB) is an antifungal drug that binds to ergosterol and forms pores at the cell membrane, causing the loss of ions. In addition, AMB induces the accumulation of reactive oxygen species (ROS), and although these molecules have multiple deleterious effects on fungal cells, their specific role in the action mechanism of AMB remains unknown. In this work, we studied the role of ROS in the action mechanism of AMB. We determined the intracellular induction of ROS in 44 isolates of different pathogenic yeast species (Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, Candida krusei, Cryptococcus neoformans, and Cryptococcus gattii). We also characterized the production of ROS in AMB-resistant isolates. We found that AMB induces the formation of ROS in all the species tested. The inhibition of the mitochondrial respiratory chain by rotenone blocked the induction of ROS by AMB and provided protection from the killing action of the antifungal. Moreover, this phenomenon was absent in strains that displayed resistance to AMB. These strains showed an alteration in the respiration rate and mitochondrial membrane potential and also had higher catalase activity than that of the AMB-susceptible strains. Consistently, AMB failed to induce protein carbonylation in the resistant strains. Our data demonstrate that the production of ROS by AMB is a universal and important action mechanism that is correlated with the fungicidal effect and might explain the low rate of resistance to the molecule. Finally, these data provide an opportunity to design new strategies to improve the efficacy of this antifungal. PMID:25155595

  4. Priming effects of tumor necrosis factor-? on production of reactive oxygen species during Toxoplasma gondii stimulation and receptor gene expression in differentiated HL-60 cells.

    PubMed

    Kikuchi-Ueda, Takane; Ubagai, Tsuneyuki; Ono, Yasuo

    2013-12-01

    Neutrophils are among the principal effector cells that protect against infectious agents, in part by producing reactive oxygen species (ROS) via the actions of tumor necrosis factor-? (TNF-?). In this study, we investigated whether HL-60 cells that had been differentiated into neutrophil-like cells by all-trans retinoic acid could be primed with TNF-? similar to human neutrophils. Our results showed that when differentiated HL-60 (dHL-60) cells were primed with TNF-? for 10 min, ROS production induced by zymosan A or phorbol myristate acetate (PMA) was enhanced in a TNF-?-dose-dependent manner. In addition, when dHL-60 cells were stimulated with live tachyzoites of Toxoplasma gondii after TNF-? priming, ROS production was also enhanced. Thus, dHL-60, similar to neutrophils, produced ROS after PMA, zymosan A, or T. gondii stimulation. Furthermore, we examined gene expression in dHL-60 cells after TNF-? treatment. The pro-inflammatory cytokine IL-6 was up-regulated more than 1.6-fold by 0.1 ng/mL TNF-?. Endogenous TNF-? was down-regulated by priming. IL-8 receptors genes were not affected by priming with 0.1 ng/mL or 1 ng/mL TNF-?. Complement receptor (CR) 1 and CR3 gene expression was not affected by TNF-? priming for 10 min. However, when the priming period was extended to 1 h, CR1 and CR3 genes were up-regulated 1.3 and 1.4-fold, respectively. Expression of the cell-surface CR3 (CD11b) was not significantly affected by TNF-? for 15 min but was slightly enhanced after priming for 2 h. These results suggest that dHL-60 cells may be used as a substitute for neutrophils when evaluating the effects of cytokines or immunomodulator agents. PMID:23740089

  5. Phenylethynyl endcapping reagents and reactive diluents

    NASA Technical Reports Server (NTRS)

    Jensen, Brian J. (inventor); Bryant, Robert G. (inventor); Hergenrother, Paul M. (inventor)

    1994-01-01

    A phenylethynyl composition which can be used to endcap nucleophilic species is employed in the production of phenylethynyl terminated reactive oligomers exclusively. These phenylethynyl terminated reactive oligomers display unique thermal characteristics, as exemplified by the model compound, 4-phenoxy 4'-phenylethynylbenzophenone, which is relatively stable at 200 C, but reacts at 350 C. In addition, a reactive diluent was prepared which decreases the melt viscosity of the phenylethynyl terminated oligomers and subsequently reacts therewith to increase density of the resulting thermoset. The novelty of this invention resides in the phenylethynyl composition used to terminate a nucleophilic reagent, resulting in the exclusive production of phenylethynyl terminated reactive oligomers which display unique thermal characteristics. A reactive diluent was also employed to decrease the melt viscosity of a phenylethynyl terminated reactive oligomer and to subsequently react therewith to increase the crosslink density of the resulting thermoset. These materials have features which make them attractive candidates for use as composite matrices and adhesives.

  6. p-Cresol Affects Reactive Oxygen Species Generation, Cell Cycle Arrest, Cytotoxicity and Inflammation/Atherosclerosis-Related Modulators Production in Endothelial Cells and Mononuclear Cells

    PubMed Central

    Chan, Chiu-Po; Yeung, Sin-Yuet; Hsien, Hsiang-Chi; Lin, Bor-Ru; Yeh, Chien-Yang; Tseng, Wan-Yu; Tseng, Shui-Kuan; Jeng, Jiiang-Huei

    2014-01-01

    Aims Cresols are present in antiseptics, coal tar, some resins, pesticides, and industrial solvents. Cresol intoxication leads to hepatic injury due to coagulopathy as well as disturbance of hepatic circulation in fatal cases. Patients with uremia suffer from cardiovascular complications, such as atherosclerosis, thrombosis, hemolysis, and bleeding, which may be partly due to p-cresol toxicity and its effects on vascular endothelial and mononuclear cells. Given the role of reactive oxygen species (ROS) and inflammation in vascular thrombosis, the objective of this study was to evaluate the effect of p-cresol on endothelial and mononuclear cells. Methods EA.hy926 (EAHY) endothelial cells and U937 cells were exposed to different concentrations of p-cresol. Cytotoxicity was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5 -diphenyltetrazolium bromide (MTT) assay and trypan blue dye exclusion technique, respectively. Cell cycle distribution was analyzed by propidium iodide flow cytometry. Endothelial cell migration was studied by wound closure assay. ROS level was measured by 2?,7?-dichlorofluorescein diacetate (DCF) fluorescence flow cytometry. Prostaglandin F2? (PGF2?), plasminogen activator inhibitor-1 (PAI-1), soluble urokinase plasminogen activator receptor (suPAR), and uPA production were determined by Enzyme-linked immunosorbant assay (ELISA). Results Exposure to 100–500 µM p-cresol decreased EAHY cell number by 30–61%. P-cresol also decreased the viability of U937 mononuclear cells. The inhibition of EAHY and U937 cell growth by p-cresol was related to induction of S-phase cell cycle arrest. Closure of endothelial wounds was inhibited by p-cresol (>100 µM). P-cresol (>50 µM) also stimulated ROS production in U937 cells and EAHY cells but to a lesser extent. Moreover, p-cresol markedly stimulated PAI-1 and suPAR, but not PGF2?, and uPA production in EAHY cells. Conclusions p-Cresol may contribute to atherosclerosis and thrombosis in patients with uremia and cresol intoxication possibly due to induction of ROS, endothelial/mononuclear cell damage and production of inflammation/atherosclerosis-related molecules. PMID:25517907

  7. Reactive collisions of two ultracold particles in a harmonic trap

    E-print Network

    Jankowska, Joanna

    2015-01-01

    We consider two ultracold particles confined in spherically symmetric harmonic trap and interacting via isotropic potential with absorbing boundary conditions at short range that models reactive scattering. First, we apply the contact pseudopotential with complex scattering length and investigate the properties of eigenergies and eigenfunctions for different trap states as a function of real and imaginary part of the scattering length. In the analyzed case the eigenenergies take complex values, and their imaginary part can be interpreted in terms of decay rates. Then we introduce the model of a square well with absorbing boundary conditions that is later used to investigate the effects of the finite range of interaction on the properties of a reactive scattering in the trap. Finally, we analyze the decay rates for some reactive alkali dimer molecules assuming short-range probability of reaction equal to unity. In this case the complex scattering length is given by universal value related to the mean scatterin...

  8. New calculations of cross-sections and charge asymmetries for lepton pair production and wide angle Bhabha scattering in e+e- collisions near the Z-peak

    NASA Astrophysics Data System (ADS)

    Field, J. H.

    1994-03-01

    A new event generator for lepton pair production and wide angle Bhabha scattering, BHAGENE3, is presented. Both electroweak and higher order (beyond O(?) QED corrections are included. Comparisons are made with results from the programs, based on the structure function formalism, ALIBABA, TOPAZ0 and ZFITTER. For the case of the final states l+l-?? ( l = e, ?, ?) BHAGENE3 results are compared with those of Monte Carlo generators that use the exact O( ?2) amplitudes.

  9. Measurement of pretzelosity asymmetry of charged pion production in Semi-Inclusive Deep Inelastic Scattering on a polarized $^3$He target

    E-print Network

    Y. Zhang; X. Qian; K. Allada; C. Dutta; J. Huang; J. Katich; Y. Wang; K. Aniol; J. R. M. Annand; T. Averett; F. Benmokhtar; W. Bertozzi; P. C. Bradshaw; P. Bosted; A. Camsonne; M. Canan; G. D. Cates; C. Chen; J. -P. Chen; W. Chen; K. Chirapatpimol; E. Chudakov; E. Cisbani; J. C. Cornejo; F. Cusanno; M. M. Dalton; W. Deconinck; C. W. de Jager; R. De Leo; X. Deng; A. Deur; H. Ding; P. A. M. Dolph; D. Dutta; L. El Fassi; S. Frullani; H. Gao; F. Garibaldi; D. Gaskell; S. Gilad; R. Gilman; O. Glamazdin; S. Golge; L. Guo; D. Hamilton; O. Hansen; D. W. Higinbotham; T. Holmstrom; M. Huang; H. F. Ibrahim; M. Iodice; X. Jiang; G. Jin; M. K. Jones; A. Kelleher; W. Kim; A. Kolarkar; W. Korsch; J. J. LeRose; X. Li; Y. Li; R. Lindgren; N. Liyanage; E. Long; H. -J. Lu; D. J. Margaziotis; P. Markowitz; S. Marrone; D. McNulty; Z. -E. Meziani; R. Michaels; B. Moffit; C. Muñoz Camacho; S. Nanda; A. Narayan; V. Nelyubin; B. Norum; Y. Oh; M. Osipenko; D. Parno; J. C. Peng; S. K. Phillips; M. Posik; A. J. R. Puckett; Y. Qiang; A. Rakhman; R. D. Ransome; S. Riordan; A. Saha; B. Sawatzky; E. Schulte; A. Shahinyan; M. H. Shabestari; S. Sirca; S. Stepanyan; R. Subedi; V. Sulkosky; L. -G. Tang; W. A. Tobias; G. M. Urciuoli; I. Vilardi; K. Wang; B. Wojtsekhowski; X. Yan; H. Yao; Y. Ye; Z. Ye; L. Yuan; X. Zhan; Y. -W. Zhang; B. Zhao; X. Zheng; L. Zhu; X. Zhu; X. Zong

    2013-12-15

    An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized $^3$He target was performed at Jefferson Lab in the kinematic region of $0.16He asymmetries and cross-section ratios between the proton and $^3$He. Our results show that for both $\\pi^{\\pm}$ on $^3$He and on the neutron the pretzelosity asymmetries are consistent with zero within experimental uncertainties.

  10. Platelet reactivity in human aortic grafts: a prospective, randomized midterm study of platelet adherence and release products in Dacron and polytetrafluoroethylene conduits

    SciTech Connect

    Wakefield, T.W.; Shulkin, B.L.; Fellows, E.P.; Petry, N.A.; Spaulding, S.A.; Stanley, J.C.

    1989-02-01

    Platelet-related phenomena at the blood-surface interface of randomly placed knitted Dacron (n = 6) and polytetrafluoroethylene (ePTFE) (n = 6) interposition aortic grafts were studied in patients undergoing abdominal aortic aneurysmectomy. Luminal accumulation of platelets was assessed by infusing indium-111-oxine (400 microCi) labeled autologous platelets and imaging grafts at 1 week, 3 months, and 6 months after surgery. Image analysis included an indium ratio technique (comparing aortic graft radioactivity to that of an iliac artery) and a red blood cell technetium subtraction technique (excluding blood pool radioactivity from graft radioactivity, with the heart or iliac artery serving as reference regions). Plasma levels of beta-thromboglobulin and platelet factor 4 were correlated with platelet accumulations on the aortic prostheses. Differences in graft radioactivity or platelet-release products were not evident 1 week after surgery. Three months after implantation, Dacron and ePTFE conduits exhibited 87% and 47% (p less than 0.05) more radioactivity with the indium ratio technique than the iliac artery. Similarly, increased Dacron compared with ePTFE graft radioactivity was noted using technetium subtraction techniques: 71% vs 30% with a heart reference and 26% vs 11% with an iliac artery reference, respectively. Increases in graft radioactivity correlated with increases in both plasma beta-thromboglobulin and platelet factor 4 at 3 months (r = 0.6 to 0.9; p less than 0.05 to 0.001 depending on the imaging technique used). At 6 months, differences did not persist. In fact, technetium subtraction techniques suggested less Dacron conduit reactivity. It is speculated that differences in platelet accumulation and activation associated with different graft substrates may prove clinically important.

  11. Method For Reactivating Solid Catalysts Used For Alklation Reactions

    DOEpatents

    Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Coates, Kyle (Shelley, ID); Zalewski, David J. (Proctorville, OH); Fox, Robert V. (Idaho Falls, ID)

    2005-05-03

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  12. Method for reactivating solid catalysts used in alkylation reactions

    DOEpatents

    Ginosar, Daniel M.; Thompson, David N.; Coates, Kyle; Zalewski, David J.; Fox, Robert V.

    2003-06-17

    A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.

  13. Fully quantum state-resolved inelastic scattering of NO(X) + Kr: Differential cross sections and product rotational alignment

    NASA Astrophysics Data System (ADS)

    Brouard, M.; Chadwick, H.; Gordon, S. D. S.; Hornung, B.; Nichols, B.; K?os, J.; Aoiz, F. J.; Stolte, S.

    2014-10-01

    Fully quantum state selected and resolved inelastic scattering of NO(X) by krypton has been investigated. Initial ?-doublet state selection is achieved using an inhomogeneous hexapole electric field. Differential cross sections and even-moment polarization dependent differential cross sections have been obtained at a collision energy of 514 cm-1 for both spin-orbit and parity conserving and changing collisions. Experimental results are compared with those obtained from quantum scattering calculations and are shown to be in very good agreement. Hard shell quantum scattering calculations are also performed to determine the effects of the different parts of the potential on the scattering dynamics. Comparisons are also made with the NO(X) + Ar system.

  14. Fully quantum state-resolved inelastic scattering of NO(X) + Kr: Differential cross sections and product rotational alignment

    SciTech Connect

    Brouard, M. Chadwick, H.; Gordon, S. D. S.; Hornung, B.; Nichols, B.; K?os, J.; Aoiz, F. J.; Stolte, S.

    2014-10-28

    Fully quantum state selected and resolved inelastic scattering of NO(X) by krypton has been investigated. Initial ?-doublet state selection is achieved using an inhomogeneous hexapole electric field. Differential cross sections and even-moment polarization dependent differential cross sections have been obtained at a collision energy of 514 cm{sup ?1} for both spin-orbit and parity conserving and changing collisions. Experimental results are compared with those obtained from quantum scattering calculations and are shown to be in very good agreement. Hard shell quantum scattering calculations are also performed to determine the effects of the different parts of the potential on the scattering dynamics. Comparisons are also made with the NO(X) + Ar system.

  15. Fully quantum state-resolved inelastic scattering of NO(X) + Kr: differential cross sections and product rotational alignment.

    PubMed

    Brouard, M; Chadwick, H; Gordon, S D S; Hornung, B; Nichols, B; K?os, J; Aoiz, F J; Stolte, S

    2014-10-28

    Fully quantum state selected and resolved inelastic scattering of NO(X) by krypton has been investigated. Initial ?-doublet state selection is achieved using an inhomogeneous hexapole electric field. Differential cross sections and even-moment polarization dependent differential cross sections have been obtained at a collision energy of 514 cm(-1) for both spin-orbit and parity conserving and changing collisions. Experimental results are compared with those obtained from quantum scattering calculations and are shown to be in very good agreement. Hard shell quantum scattering calculations are also performed to determine the effects of the different parts of the potential on the scattering dynamics. Comparisons are also made with the NO(X) + Ar system. PMID:25362298

  16. Double spin asymmetry AL?T? in charged pion production from deep inelastic scattering on a transversely polarized ³He target

    E-print Network

    Huang, Jin, Ph. D. Massachusetts Institute of Technology

    2012-01-01

    In this thesis I discuss the first measurement of the beam-target double-spin asymmetry ALT for charged pion electroproduction in deep inelastic electron scattering on a transversely polarized 3He target. These data were ...

  17. Reactive scattering calculations for {sup 87}Rb+{sup 87}RbHe?Rb{sub 2}({sup 3}?{sub u}{sup +},v)+He from ultralow to intermediate energies

    SciTech Connect

    Rodríguez-Cantano, Rocío; González-Lezana, Tomás; Prosmiti, Rita; Delgado-Barrio, Gerardo; Villarreal, Pablo; Jellinek, Julius

    2015-04-28

    We investigate atom-diatom reactive collisions, as a preliminary step, in order to assess the possibility of forming Rb{sub 2} molecules in their lowest triplet electronic state by cold collisions of rubidium atoms on the surface of helium nanodroplets. A simple model related to the well-known Rosen treatment of linear triatomic molecules [N. Rosen, J. Chem. Phys. 1, 319 (1933)] in relative coordinates is used, allowing to estimate reactive probabilities for different values of the total angular momentum. The best available full dimensional potential energy surface [Guillon et al., J. Chem. Phys. 136, 174307 (2012)] is employed through the calculations. Noticeable values of the probabilities in the ultracold regime, which numerically fulfill the Wigner threshold law, support the feasibility of the process. The rubidium dimer is mainly produced at high vibrational states, and the reactivity is more efficient for a bosonic helium partner than when the fermion species is considered.

  18. Rayleigh Scattering.

    ERIC Educational Resources Information Center

    Young, Andrew T.

    1982-01-01

    The correct usage of such terminology as "Rayleigh scattering,""Rayleigh lines,""Raman lines," and "Tyndall scattering" is resolved during an historical excursion through the physics of light-scattering by gas molecules. (Author/JN)

  19. Distribution and production of reactive mercury and dissolved gaseous mercury in surface waters and water/air mercury flux in reservoirs on Wujiang River, Southwest China

    NASA Astrophysics Data System (ADS)

    Fu, Xuewu; Feng, Xinbin; Guo, Yanna; Meng, Bo; Yin, Runsheng; Yao, Heng

    2013-05-01

    Transformation and distribution of mercury (Hg) species play an important role in the biogeochemical cycling of mercury in aquatic systems. Measurements of water/air exchange fluxes of Hg, reactive mercury (RHg), and dissolved gaseous mercury (DGM) concentrations were conducted at 14 sites in five reservoirs on the Wujiang River, Guizhou, Southwest China. Clear spatial and temporal variations in Hg fluxes, RHg, and DGM concentrations were observed in the study area. Hg fluxes and RHg concentrations exhibited a consistent diurnal variation in the study area, with maximum fluxes and concentrations during daytime. A typical diurnal trend of DGM with elevated concentration at night was observed in a eutrophic reservoir with elevated bacteria abundance, suggesting a bacteria-induced production of DGM in this reservoir. For other reservoirs, a combination of sunlight-stimulated production and loss via photo-induced oxidation and evaporation regulated the diurnal trends of DGM. Seasonal variations with elevated Hg fluxes and RHg concentrations in warm season were noticeable in the study area, which highlighted the combined effect of interrelationships between Hg species in water and environmental parameters. Hg fluxes exhibited much more significant correlations with RHg and THg concentrations and air temperature compared to DGM concentrations and solar radiation. The measured fluxes were significantly higher than those simulated using the water/air thin film Hg0 gradient model. Aside from the potential limitations of dynamic flux chamber method, this may also suggest the thin film gas exchange model is not capable of predicting water/air Hg flux under low wind speed conditions. Additionally, it is speculated that DGM concentrations might vary significantly in surface waters with depth, and measurements of DGM at a depth of 2-4 cm below the water surface probably underestimated the DGM concentration that should be taken into account in simulations of water/air flux using the thin film gas exchange model. An empirical model of water/air Hg flux was developed, and the simulated fluxes were compared well with measurements. The model yields a mean annual Hg emission of 3.2 ± 1.0 kg in the study area.

  20. Double Parton Scattering cross section limit from same-sign W bosons pair production in di-muon final state at LHC

    E-print Network

    CMS Collaboration

    2015-01-01

    The double parton scattering (DPS) in proton-proton collisions at a center-of-mass energy of 8 TeV has been investigated using the same-sign W boson pair final state, with each W boson decaying into muon and associated neutrino. The data sample corresponds to an integrated luminosity of $19.7$ fb$^{-1}$ collected by the CMS detector at the Large Hadron Collider. The observables sensitive to double parton scattering are defined and studied, followed by a multivariate analysis in order to enhance the process sensitivity. A limit on the DPS yield, along with the corresponding limit on the production cross section ($\\sigma^{DPS}_{WW}$), has been evaluated.

  1. Computational chemistry of natural products: a comparison of the chemical reactivity of isonaringin calculated with the M06 family of density functionals.

    PubMed

    Glossman-Mitnik, Daniel

    2014-07-01

    The M06 family of density functionals has been assessed for the calculation of the molecular structure and properties of the Isonaringin flavonoid that can be an interesting material for dye-sensitized solar cells (DSSC). The chemical reactivity descriptors have been calculated through chemical reactivity theory within DFT (CR-DFT). The active sites for nucleophilic and electrophilic attacks have been chosen by relating them to the Fukui function indices and the dual descriptor f ((2))(r). A comparison between the descriptors calculated through vertical energy values and those arising from the Janak's theorem approximation have been performed in order to check for the validity of the last procedure. PMID:24992989

  2. Dynamics of inelastic and reactive gas-surface collisions

    SciTech Connect

    Smoliar, L.A.

    1995-04-01

    The dynamics of inelastic and reactive collisions in atomic beam-surface scattering are presented. The inelastic scattering of hyperthermal rare gaseous atoms from three alkali halide surfaces (LiF, NaCl, GI)was studied to understand mechanical energy transfer in unreactive systems. The dynamics of the chemical reaction in the scattering of H(D) atoms from the surfaces of LIF(001) and the basal plane of graphite were also studied.

  3. System for reactivating catalysts

    DOEpatents

    Ginosar, Daniel M. (Idaho Falls, ID); Thompson, David N. (Idaho Falls, ID); Anderson, Raymond P. (Idaho Falls, ID)

    2010-03-02

    A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.

  4. Production of Nurr-1 Specific Polyclonal Antibodies Free of Cross-reactivity Against Its Close Homologs, Nor1 and Nur77.

    PubMed

    Leblanc, Pierre; Moon, Minho; Kim, Woori; Jeong, Inhye; Kim, Chun-Hyung; Kim, Kwang-Soo

    2015-01-01

    The nuclear receptor subfamily 4 (NR4A) is composed of 3 related proteins sharing a DNA binding domain (DBD) and a ligand-binding domain (LBD). The nuclear receptor related 1 protein (Nurr1 or NR4A2) plays a key role in the maintenance of the dopaminergic system. Dopamine dysfunctions associated with the Nurr1 gene include Parkinson's disease, schizophrenia and manic depression among others. Furthermore, recent evidence indicates that Nurr1 is also expressed in other brain areas such as the hippocampus and plays critical roles for learning and memory. The other members of the family are nerve growth factor IB (Nur77 or NR4A1) and neuron-derived orphan receptor 1 (NOR1 or NR4A3). To help investigate the precise functional roles of Nurr1 in dopaminergic and other brain region-related neuronal dysfunctions antibodies devoid of cross-reactivities against Nur77 and NOR1 were needed. Since the proteins are more divergent in their LBDs than in their DNA binding domains immunization with purified LBDs should yield antibodies specific for Nurr1 with minimal reactivities against Nur77 and/or NOR1. Although anti-Nurr1 antibodies were successfully generated these showed significant immunoreactivity against the other members of the family. Affinity chromatography over immobilized Protein A followed by pre-adsorption against immobilized Nur77 and NOR1 LBDs yielded Nurr1 specific antibodies free of cross-reactivity. Here, we selectively target antibodies against a specific member of a highly conserved family of proteins by immunizing animals with their most divergent regions followed by removing cross reactive antibodies by pre-adsorption. The goal of the protocol is to increase polyclonal antibodies specificity through pre-adsorption against cross-reactive antigens. PMID:26325389

  5. Reactive Valuations MSc Thesis (Afstudeerscriptie)

    E-print Network

    Koolen, Marijn

    Reactive Valuations MSc Thesis (Afstudeerscriptie) written by Bert Christiaan Regenboog (born April . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Reactive valuations 9 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2 Reactive valuations . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.3 Reactive

  6. Enhanced Oxidative Reactivity for Anthracite Coal via a Reactive Ball Milling Pretreatment Step

    SciTech Connect

    Angela D. Lueking; Apurba Sakti; Dania Alvarez-Fonseca; Nichole Wonderling

    2009-09-15

    Reactive ball milling in a cyclohexene solvent significantly increases the oxidative reactivity of an anthracite coal, due to the combined effects of particle size reduction, metal introduction, introduction of volatile matter, and changes in carbon structure. Metals introduced during milling can be easily removed via a subsequent demineralization process, and the increased reactivity is retained. Solvent addition alters the morphological changes that occur during pyrolysis and leads to a char with significantly increased reactivity. When the solvent is omitted, similar effects are seen for the milled product, but a significant fraction of the char is resistant to oxidation. 33 refs., 3 figs., 1 tab.

  7. 2,3,7,8-Tetrachlorodibenzo-p-dioxin increases reactive oxygen species production in human endothelial cells via induction of cytochrome P4501A1

    SciTech Connect

    Kopf, P.G.; Walker, M.K.

    2010-05-15

    Studies in our laboratory have demonstrated that subchronic 2,3,7,8,-tetrachlorodibenzo-p-dioxin (TCDD) exposure of adult mice results in hypertension, cardiac hypertrophy, and reduced nitric oxide (NO)-mediated vasodilation. Moreover, increased superoxide anion production was observed in cardiovascular organs of TCDD-exposed mice and this increase contributed to the reduced NO-mediated vasodilation. Since cytochrome P4501A1 (CYP1A1) can contribute to some TCDD-induced toxicity, we tested the hypothesis that TCDD increases reactive oxygen species (ROS) in endothelial cells by the induction of CYP1A1. A concentration-response to 24 h TCDD exposure (10 pM-10 nM) was performed in confluent primary human aortic endothelial cells (HAECs). Oxidant-sensitive fluorescent probes dihydroethidium (DHE) and 2',7'-dichlorofluorescin diacetate (DCFH-DA), were used to measure superoxide anion, and hydrogen peroxide and hydroxyl radical, respectively. NO was also measured using the fluorescent probe diaminofluorescein-2 diacetate (DAF-2DA). These assessments were conducted in HAECs transfected with siRNA targeting the aryl hydrocarbon receptor (AhR), CYP1A1, or CYP1B1. TCDD concentration-dependently increased CYP1A1 and CYP1B1 mRNA, protein, and enzyme activity. Moreover, 1 nM TCDD maximally increased DHE (Cont = 1.0 +- 0.3; TCDD = 5.1 +- 1.0; p = 0.002) and DCFH-DA (Cont = 1.0 +- 0.2; TCDD = 4.1 +- 0.5; p = 0.002) fluorescence and maximally decreased DAF-2DA fluorescence (Cont = 1.0 +- 0.4; TCDD = 0.68 +- 0.1). siRNA targeting AhR and CYP1A1 significantly decreased TCDD-induced DHE (siAhR: Cont = 1.0 +- 0.1; TCDD = 1.3 +- 0.2; p = 0.093) (siCYP1A1: Cont = 1.0 +- 0.1; TCDD = 1.1 +- 0.1; p = 0.454) and DCFH-DA (siAhR: Cont = 1.0 +- 0.2; TCDD = 1.3 +- 0.3; p = 0.370) (siCYP1A1: Cont = 1.0 +- 0.1; TCDD = 1.3 +- 0.2; p = 0.114) fluorescence and increased DAF-2DA fluorescence (siAhR: Cont = 1.00 +- 0.03; TCDD = 0.97 +- 0.03; p = 0.481) (siCYP1A1: Cont = 1.00 +- 0.03; TCDD = 0.92 +- 0.03; p = 0.034), while siRNA targeting CYP1B1 did not. These data suggest that TCDD-induced increase in ROS is AhR-dependent and may be mediated, in part, by CYP1A1 induction.

  8. Production of reactive oxygen (H2O2) and nitrogen (NO) intermediates and tnf-? in mice genetically selected for high (H) and low (L) antibody response and experimentally infected with Leptospira serovar pomona

    PubMed Central

    Haanwinckel, Maria Cristina Santos; de Oliveira, Silvio Luis

    2011-01-01

    The aim of the present study was to evaluate the activity of macrophages, and the production of TNF-? and antibodies against experimental infection by Leptospira serovar Pomona in mice genetically selected for High (H) or Low (L) humoral immune response. To evaluate macrophagic activity, peritoneal and splenic lavages were performed for determination of oxygen (H2O2) and nitrogen (NO) intermediates. The production of the tumor necrosis factor (TNF-?) was investigated through bioassays in serum and homogenates of splenic and hepatic cells of control and infected animals, as was as specific antibodies production. The immune response against serovar Pomona in those lines, was characterized by high antibody production, especially in later periods of the infectious process, whereas values of bacterial recovery in culture medium were lower. The production of reactives oxygen and nitrogen intermediate, also helped to eliminate Leptospira Pomona in both lines; H2O2 production an important factor in HIV-A, as well as NO production in LIV-A, especially in later post-inoculation periods. The same was detected for TNF-?. Results suggest that such lines could be an important model to investigate the pathogenesis and the immune response of animals against the several Leptospira serovars. PMID:24031688

  9. PLÉIADES: Responsiveness, Flexibility, Reactivity

    NASA Astrophysics Data System (ADS)

    Gabriel-Robez, C.; Lees, R.; Bernard, M.

    2012-08-01

    By the end of 2011, Astrium GEO-Information Services launched Pléiades 1, the first of two identical optical imaging satellites that will be operated on a phased orbit. This satellite system, designed by the French Space Agency, CNES, based upon French Defense specifications, will provide 50-cm products in record time. The overall aim of this paper is to describe the benefits of the innovative features of Pléiades 1 and its operations, so as to assess their combined potential in emergency situations, crisis recovery, regular monitoring or large area mapping. Specific care will be brought to describe the reactivity enabled by the system. Based on real-life examples, the paper will lead the analysis on the two main components of the system. On the one hand, the space segment will be presented through the following characteristics: revisit capacity, agility, acquisition capacity and acquisition scenarios (target, single-pass mosaics, stereo, tristereo, linear monitoring, persistent surveillance). On the other hand, the flexibility of the ground segment will be assessed. The benefits of multiple tasking plans per day, direct tasking capacity, automated processing and on-line ordering and delivering will be illustrated, tested and qualified for applications requiring a high level of responsiveness and reactivity. The presentation will end with a summary of the benefits of the space segment features and the flexibility of the ground segment, fine-tuned to answer both military and civilian / commercial needs. The analysis will be extended in the perspective of the second Pléiades' launch, highlighting the advantages of having two satellites operating on a phased orbit, affording a daily revisit anywhere on Earth, with very high resolution.

  10. Dynamics in reactive bubbly flow

    NASA Astrophysics Data System (ADS)

    Sundararajan, Pavithra; Koch, Donald; Stroock, Abraham

    2010-11-01

    Multiphase flow in microfluidic channels encompasses a rich collection of phenomena of widespread interest in both fundamental and technological context. While studies on non reactive multiphase flow focus on the dynamics of bubble breakup, coalescence and stability, a reactive multiphase flow opens up a broader spectrum of dynamics, like nucleation, growth and detachment of bubbles as well as the secondary mixing in the slugs during these processes. Our interest lies in the flow in an electrochemical microfluidic fuel cell with liquid reactants reacting at catalyst walls producing gaseous products which choke the fuel cell efficiency due to uncontrolled bubbly flow. This challenge is an opportunity in itself provided the multiphase flow dynamics can be characterized to achieve a stable Taylor regime. Taylor regime allows for promisingly high efficiencies due to improved mass transfer of reactants to the concentration boundary layer of the electrodes achieved by the secondary flow in the liquid phase present between bubbles. Here, I will experimentally explore the different regimes of reactive bubbly flow in a microchannel. The phase diagram of the reactive multiphase flows would be used to identify the stable regime for efficient fuel cell operation. Further, I will study the mass transfer in the presence of multiphase flow to regimes of enhanced mass transfer, and compare it with numerical models.

  11. First OH reactivity measurements in Harvard Forest

    NASA Astrophysics Data System (ADS)

    Herdlinger-Blatt, I. S.; Martin, S. T.; Hansel, A.; McKinney, K. A.

    2013-12-01

    The OH reactivity provides critical insight into the HOx budget under actual atmospheric conditions, and has implications for the production of ozone and the formation of secondary organic material. Previous studies have indicated that the OH reactivity measured at field sites often exceeds model estimations, but current experiments remain inconclusive about the origin of the discrepancy between the modeled and measured OH reactivity (Lou et al., 2010). As of now there are only a limited number of atmospheric studies of total OH reactivity available, so to improve understanding of the OH reactivity more studies are needed. The first OH reactivity measurements in the northeastern United States are being performed during the summer of 2013 at Harvard Forest. Harvard forest, is located about 100 km west of the Boston metropolitan area, is one of the most intensively studied forests in North America. The main biogenic VOC emitted from Harvard Forest is isoprene followed by monoterpenes and methanol. Sampling for the OH reactivity measurements will be conducted from a 30m tall meteorological tower at the Harvard Forest site. The air is drawn into a reaction cell where the OH reactivity is determined using the Comparative Reactivity Method (Sinha et al., 2008) employing a High-Sensitivity Proton Transfer Reaction Mass Spectrometer (Lindinger et al., 1998, Hansel et al., 1998). In addition to the OH reactivity measurements, the most abundant compounds present in the air sample will be quantified using PTR-MS. The quantification of these compounds is needed to compare the theoretical calculated OH reactivity with the measured OH reactivity data. The measurements will be used to evaluate our understanding of the OH budget at Harvard Forest. References: A. Hansel, A. Jordan, C. Warneke, R. Holzinger, and W. Lindinger.: Improved Detection Limit of the Proton-transfer Reaction Mass Spectrometer: On-line Monitoring of Volatile Organic Compounds at Mixing Ratios of a Few PPTV, Rapid Commun. Mass Spectrom., 12, 871-875, (1998). W. Lindinger, A. Hansel, and A. Jordan: Proton-transfer-reaction mass spectrometry (PTR-MS): on-line monitoring of volatile organic compounds at pptv levels. Chemical Society Reviews , 27, 1998. S. Lou, F. Holland, F. Rohrer, K. Lu, B. Bohn, T. Brauers, C. C. Chang, H. Fuchs, R. Häseler, K. Kita, Y. Kondo, X. Li, M. Shao, L. Zeng, A. Wahner, Y. Zhang, W. Wang, and A. Hofzumahaus, Atmospheric OH reactivities in the Pearl River Delta - China in summer 2006: measurement and model results, Atmos. Chem. Phys., 10, 11243-11260, (2010). V. Sinha, J. Williams, J.N. Crowley, and J. Lelieveld., The Comparaptive Reactivity Methode - a new tool to measure total OH Reactivity in ambient air, Atmos. Env., 38, 2511-2522, (2008).

  12. Reactive multiphase flow simulation workshop summary

    SciTech Connect

    VanderHeyden, W.B.

    1995-09-01

    A workshop on computer simulation of reactive multiphase flow was held on May 18 and 19, 1995 in the Computational Testbed for Industry at Los Alamos National Laboratory (LANL), Los Alamos, New Mexico. Approximately 35 to 40 people attended the workshop. This included 21 participants from 12 companies representing the petroleum, chemical, environmental and consumer products industries, two representatives from the DOE Office of Industrial Technologies and several from Los Alamos. The dialog at the meeting suggested that reactive multiphase flow simulation represents an excellent candidate for government/industry/academia collaborative research. A white paper on a potential consortium for reactive multiphase flow with input from workshop participants will be issued separately.

  13. Production of two charm quark-antiquark pairs in single-parton scattering within the kt-factorization approach

    NASA Astrophysics Data System (ADS)

    van Hameren, Andreas; Maciu?a, Rafa?; Szczurek, Antoni

    2015-09-01

    We present first results for the 2 ? 4 single-parton scattering gg ? c c bar c c bar subprocess for the first time fully within the kt-factorization approach. In this calculation we have used the Kimber-Martin-Ryskin unintegrated gluon distribution which effectively includes some class of higher-order gluon emissions, and an off-shell matrix element squared calculated using recently developed techniques. The results are compared with our earlier result obtained within the collinear-factorization approach. Only slightly larger cross sections are obtained than in the case of the collinear approach. Inclusion of transverse momenta of gluons entering the hard process leads to a much stronger azimuthal decorrelation between cc and c bar c bar than in the collinear-factorization approach. A comparison to predictions of double parton scattering (DPS) results and the LHCb data strongly suggests that the assumption of two fully independent DPS (gg ? c c bar ? gg ? c c bar) may be too approximate.

  14. The production, localization and spreading of reactive oxygen species contributes to the low vitality of long-term stored common beech (Fagus sylvatica L.) seeds.

    PubMed

    Ratajczak, Ewelina; Ma?ecka, Arleta; Bagniewska-Zadworna, Agnieszka; Kalemba, Ewa Marzena

    2015-02-01

    The common beech (Fagus sylvatica L.) is propagated by seeds, but the seed set is irregular with five to ten years in between crops. It is therefore necessary to store the seeds. However, beech seeds lose germinability during long-term storage. In this study, beech seeds were stored at -10°C under controlled conditions for 2, 5, 8, 11 and 13 years. Our results show that beech seeds lose germinability during storage in proportion to the duration of storage. The decrease in germinability correlated with increased electrolyte leakage and accumulation of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. Furthermore, a strong positive correlation was observed among the releases of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. In situ localization showed that superoxide anion radicals and hydrogen peroxide were first detectable in root cap cells. When the seed storage time was extended, the reactive oxygen species fluorescence expanded to more areas of the radicle, reaching the root apical meristem. A storage time-dependent decrease in catalase activity, observed in both embryonic axes and cotyledons, was also positively correlated with germinability. DNA fragmentation was observed in beech seeds during storage and occurred predominantly in embryonic axes stored for 5 years and more. Altogether, these results suggest that the loss of germinability in beech seeds during long-term storage depends on several factors, including strong of reactive oxygen species accumulation accompanied by reduced catalase activity as well as membrane injury and DNA alternations, which may be aging-related and ROS-derived. We suggest that the accumulating reactive oxygen species that spread to the root apical meristem are key factors that affect seed germinability after long-term storage. PMID:25462977

  15. Production of a rabbit anti-cockatiel immunoglobulin G and characterization of its cross-reactivities with immunoglobulin G of other psittacine species.

    PubMed

    Baghian, A; Reyes, C V; Mendoza, A; Tully, T N; Kousoulas, K G

    1999-01-01

    The purpose of this work was to produce rabbit anti-cockatiel immunoglobulin G (IgG) and compare its cross-reactivity with sera from eight other psittacine birds: Quaker parakeet, budgerigar, green-wing macaw, blue-fronted Amazon parrot, eclectus parrot, African grey parrot, Patagonian conure, Moluccan cockatoo. Cockatiel IgG did not bind to protein A or G; therefore, these proteins could not be used in column chromatography to isolate the IgG. A combination of serum IgG precipitation by ammonium sulfate and yolk IgG extraction from egg was loaded in sodium dodecyl sulfate-polyacrylamide gel upon which the IgG was resolved by electrophoresis. The resolved IgG in sodium dodecyl sulfate-polyacrylamide gel was stained with Coomassie blue, cut, crushed in phosphate-buffered saline, and injected into rabbits. The rabbit anti-cockatiel IgG produced in this way reacted with a single protein in gel immunodiffusion assay with all nine psittacine bird sera but not with those of chicken and ostrich. Immunoelectrophoresis confirmed the cross-reactivity of different psittacine sera with the anti-cockatiel IgG serum but not with ostrich and chicken sera. This antiserum detected antibody responses in sera from cockatiels vaccinated against chlamydial major outer membrane protein in an immunoblot assay. PMID:10216759

  16. Reactive Nano-Composites: Structure-Reactivity Relationship

    E-print Network

    Mukasyan, Alexander

    Reactive Nano-Composites: Structure-Reactivity Relationship Research Objectives The primary goal) on the microstructure and the reactivity of variety of nanostructured reactive composite materials, such as Ni-Al, Ti-C, Ti-Si, Ta-C, Si-C, . Approach: Reactive composites are produced by short term HEBM. The structures

  17. Reactivity of calcined petroleum cokes

    SciTech Connect

    Slitsan, V.V.; Kolodin, E.A.; Tatishchev, A.S.; Tekiev, Yu.M.; Soshkin, S.V.

    1986-02-10

    One of the most important properties of cokes as fillers for electrode production, in particular in anode pastes for self-baking anodes and electrode masses for baked anodes in aluminum cells, is their reactivity. It largely determines the properties of baked anodes, influences their consumption during electrolysis, and determines the burnoff loss of coke material during calcination. Since the consumption of coke in these processes should be regarded as the result of combustion, problems of reduction of unproductive losses of calcined material cannot be solved successfully without studies of development of the reactive properties of cokes during heat treatment. The main type of coke used at present for anode production is petroleum cokes from delayed coking units (DCU coke), produced by the Ministry of the Petrochemical industry of the USSR in accordance with GOST 22898-78. To confer the necessary technical properties (definite electrical conductivity and density) on the coke, it is calcined at 1200-1300/sup 0/. In the present work the authors studied the reactivity of low-sulfur DCU cokes.

  18. Vaccum solutions of five-dimensional Einstein equations generated by inverse scattering method II : Production of black ring solution

    E-print Network

    Shinya Tomizawa; Masato Nozawa

    2006-06-16

    We study vacuum solutions of five-dimensional Einstein equations generated by the inverse scattering method. We reproduce the black ring solution which was found by Emparan and Reall by taking the Euclidean Levi-Civita metric plus one-dimensional flat space as a seed. This transformation consists of two successive processes; the first step is to perform the three-solitonic transformation of the Euclidean Levi-Civita metric with one-dimensional flat space as a seed. The resulting metric is the Euclidean C-metric with extra one-dimensional flat space. The second is to perform the two-solitonic transformation by taking it as a new seed. Our result may serve as a stepping stone to find new exact solutions in higher dimensions.

  19. Sensitivities in the production of spread-out Bragg peak dose distributions by passive scattering with beam current modulation

    SciTech Connect

    Lu, H.-M.; Brett, Robert; Engelsman, Martijn; Slopsema, Roelf; Kooy, Hanne; Flanz, Jay

    2007-10-15

    A spread-out Bragg peak (SOBP) is used in proton beam therapy to create a longitudinal conformality of the required dose to the target. In order to create this effect in a passive beam scattering system, a variety of components must operate in conjunction to produce the desired beam parameters. We will describe how the SOBP is generated and will explore the tolerances of the various components and their subsequent effect on the dose distribution. A specific aspect of this investigation includes a case study involving the use of a beam current modulated system. In such a system, the intensity of the beam current can be varied in synchronization with the revolution of the range-modulator wheel. As a result, the weights of the pulled-back Bragg peaks can be individually controlled to produce uniform dose plateaus for a large range of treatment depths using only a small number of modulator wheels.

  20. Sensitivities in the production of spread-out Bragg peak dose distributions by passive scattering with beam current modulation.

    PubMed

    Lu, Hsiao-Ming; Brett, Robert; Engelsman, Martijn; Slopsema, Roelf; Kooy, Hanne; Flanz, Jay

    2007-10-01

    A spread-out Bragg peak (SOBP) is used in proton beam therapy to create a longitudinal conformality of the required dose to the target. In order to create this effect in a passive beam scattering system, a variety of components must operate in conjunction to produce the desired beam parameters. We will describe how the SOBP is generated and will explore the tolerances of the various components and their subsequent effect on the dose distribution. A specific aspect of this investigation includes a case study involving the use of a beam current modulated system. In such a system, the intensity of the beam current can be varied in synchronization with the revolution of the range-modulator wheel. As a result, the weights of the pulled-back Bragg peaks can be individually controlled to produce uniform dose plateaus for a large range of treatment depths using only a small number of modulator wheels. PMID:17985630

  1. Rayleigh Scattering Fundamental in understanding particle scattering

    E-print Network

    Zhang, Guifu

    , absorption cross sections · Scattering cross section · Radar cross section · Absorption cross section + 2 [# ^ks $ ( ^ks $ r ei)] · Differential cross section · Scattering field pattern · Scattering powerRayleigh Scattering · Fundamental in understanding particle scattering · Widely used in radar

  2. Hydrothermal Reactivity of Amines

    NASA Astrophysics Data System (ADS)

    Robinson, K.; Shock, E.; Hartnett, H. E.; Williams, L. B.; Gould, I.

    2013-12-01

    The reactivity of aqueous amines depends on temperature, pH, and redox state [1], all of which are highly variable in hydrothermal systems. Temperature and pH affect the ratio of protonated to unprotonated amines (R-NH2 + H+ = R-NH3+), which act as nucleophiles and electrophiles, respectively. We hypothesize that this dual nature can explain the pH dependence of reaction rates, and predict that rates will approach a maximum at pH = pKa where the ratio of protonated and unprotonated amines approaches one and the two compounds are poised to react with one another. Higher temperatures in hydrothermal systems allow for more rapid reaction rates, readily reversible reactions, and unique carbon-nitrogen chemistry in which water acts as a reagent in addition to being the solvent. In this study, aqueous benzylamine was used as a model compound to explore the reaction mechanisms, kinetics, and equilibria of amines under hydrothermal conditions. Experiments were carried out in anoxic silica glass tubes at 250°C (Psat) using phosphate-buffered solutions to observe changes in reaction rates and product distributions as a function of pH. The rate of decomposition of benzylamine was much faster at pH 4 than at pH 9, consistent with the prediction that benzylamine acts as both nucleophile and an electrophile, and our estimate that the pKa of benzylamine is ~5 at 250°C and Psat. Accordingly, dibenzylamine is the primary product of the reaction of two benzylamine molecules, and this reaction is readily reversible under hydrothermal conditions. Extremely acidic or basic pH can be used to suppress dibenzylamine production, which also suppresses the formation of all other major products, including toluene, benzyl alcohol, dibenzylimine, and tribenzylamine. This suggests that dibenzylamine is the lone primary product that then itself reacts as a precursor to produce the above compounds. Analog experiments performed with ring-substituted benzylamine derivatives and chiral methylbenzylamine suggest an SN2 mechanism for the formation of dibenzylamine. These results show the interdependence of pH and speciation with amine reaction rates. We predict the distribution of primary, secondary, tertiary, and quaternary amines in hydrothermal solutions can be used to solve for the pH of subsurface reaction zones in hydrothermal systems. [1] McCollom, T.M. (2013) The influence of minerals on decomposition of the n-alkyl-?-amino acid norvaline under hydrothermal conditions. Geochim. Cosmochim. Acta, 104, 330-357.

  3. Single spin asymmetries in charged kaon production from semi-inclusive deep inelastic scattering on a transversely polarized 3He target

    NASA Astrophysics Data System (ADS)

    Zhao, Y. X.; Wang, Y.; Allada, K.; Aniol, K.; Annand, J. R. M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J.-P.; Chen, W.; Chirapatpimol, K.; Chudakov, E.; Cisbani, E.; Cornejo, J. C.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; De Leo, R.; Deng, X.; Deur, A.; Ding, H.; Dolph, P. A. M.; Dutta, C.; Dutta, D.; El Fassi, L.; Frullani, S.; Gao, H.; Garibaldi, F.; Gaskell, D.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Guo, L.; Hamilton, D.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Huang, M.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Jin, G.; Jones, M. K.; Katich, J.; Kelleher, A.; Kim, W.; Kolarkar, A.; Korsch, W.; LeRose, J. J.; Li, X.; Li, Y.; Lindgren, R.; Liyanage, N.; Long, E.; Lu, H.-J.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; McNulty, D.; Meziani, Z.-E.; Michaels, R.; Moffit, B.; Muñoz Camacho, C.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Oh, Y.; Osipenko, M.; Parno, D.; Peng, J.-C.; Phillips, S. K.; Posik, M.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Rakhman, A.; Ransome, R.; Riordan, S.; Saha, A.; Sawatzky, B.; Schulte, E.; Shahinyan, A.; Shabestari, M. H.; Širca, S.; Stepanyan, S.; Subedi, R.; Sulkosky, V.; Tang, L.-G.; Tobias, A.; Urciuoli, G. M.; Vilardi, I.; Wang, K.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Ye, Y.; Ye, Z.; Yuan, L.; Zhan, X.; Zhang, Y.; Zhang, Y.-W.; Zhao, B.; Zheng, X.; Zhu, L.; Zhu, X.; Zong, X.; Jefferson Lab Hall A Collaboration

    2014-11-01

    We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1 production. While the Collins and Sivers moments for K+ are consistent with zero within the experimental uncertainties, both moments for K- favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the K+ Sivers moments are consistent with the prediction, the K- results differ from the prediction at the 2-sigma level.

  4. Measurement of "pretzelosity" asymmetry of charged pion production in semi-inclusive deep inelastic scattering on a polarized 3He target

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Qian, X.; Allada, K.; Dutta, C.; Huang, J.; Katich, J.; Wang, Y.; Aniol, K.; Annand, J. R. M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J.-P.; Chen, W.; Chirapatpimol, K.; Chudakov, E.; Cisbani, E.; Cornejo, J. C.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; De Leo, R.; Deng, X.; Deur, A.; Ding, H.; Dolph, P. A. M.; Dutta, D.; El Fassi, L.; Frullani, S.; Gao, H.; Garibaldi, F.; Gaskell, D.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Guo, L.; Hamilton, D.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, M.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Jin, G.; Jones, M. K.; Kelleher, A.; Kim, W.; Kolarkar, A.; Korsch, W.; LeRose, J. J.; Li, X.; Li, Y.; Lindgren, R.; Liyanage, N.; Long, E.; Lu, H.-J.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; McNulty, D.; Meziani, Z.-E.; Michaels, R.; Moffit, B.; Muñoz Camacho, C.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Oh, Y.; Osipenko, M.; Parno, D.; Peng, J. C.; Phillips, S. K.; Posik, M.; Puckett, A. J. R.; Qiang, Y.; Rakhman, A.; Ransome, R. D.; Riordan, S.; Saha, A.; Sawatzky, B.; Schulte, E.; Shahinyan, A.; Shabestari, M. H.; Širca, S.; Stepanyan, S.; Subedi, R.; Sulkosky, V.; Tang, L.-G.; Tobias, W. A.; Urciuoli, G. M.; Vilardi, I.; Wang, K.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Ye, Y.; Ye, Z.; Yuan, L.; Zhan, X.; Zhang, Y.-W.; Zhao, B.; Zheng, X.; Zhu, L.; Zhu, X.; Zong, X.; Jefferson Lab Hall A Collaboration

    2014-11-01

    An experiment to measure single-spin asymmetries of semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized 3He target was performed at Jefferson Laboratory in the kinematic region of 0.16

  5. Single spin asymmetries in charged kaon production from semi-inclusive deep inelastic scattering on a transversely polarized He3 target

    DOE PAGESBeta

    Zhao, Y. X.; Wang, Y.; Allada, K.; Aniol, K.; Annand, J. R.M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; et al

    2014-11-03

    We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1 bj+ and K– production. While the Collins and Sivers moments for K+ are consistent with zero within the experimental uncertainties, both moments for K– favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. Whilemore »the K+ Sivers moments are consistent with the prediction, the K– results differ from the prediction at the 2-sigma level.« less

  6. Lumbar disc surgery and variations in C-reactive protein, erythrocyte sedimentation rate and the complement split product C 3 d.

    PubMed

    Kock-Jensen, C; Brandslund, I; Søgaard, I

    1988-01-01

    Lumbar disc surgery was performed in fifty consecutive patients and variation in erythrocyte sedimentation rate (ESR), complement C 3 d, and C-reactive protein (CRP) levels before and after surgery were recorded. Preoperative values were within normal limits in all patients. Postoperatively, CRP increased immediately, with a maximum of 28.5 mg/l on the 2nd day and were normalized within 6 days. The maximum ESR elevation occurred after the 6th day and was followed by a slow decrease. After 12 weeks some patients still had an elevated ESR. Plasma C 3 varied pari passu with the ESR. Uncomplicated recovery after lumbar disc surgery seems to be indicated by a normalization of CRP, regardless of ESR values. Therefore, ESR may not be so useful as an indicator of disc space inflammation as previously accepted. PMID:3257837

  7. Spirafolide from bay leaf (Laurus nobilis) prevents dopamine-induced apoptosis by decreasing reactive oxygen species production in human neuroblastoma SH-SY5Y cells.

    PubMed

    Ham, Ahrom; Kim, Bora; Koo, Uk; Nam, Kung-Woo; Lee, Sung-Jin; Kim, Kyeong Ho; Shin, Jongheon; Mar, Woongchon

    2010-12-01

    Reactive oxygen species (ROS) are important mediators in many neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. This study tested the neuroprotective effects of spirafolide, a compound purified from the leaves of Laurus nobilis L. (Lauraceae), against dopamine (DA)-induced apoptosis in human neuroblastoma SH-SY5Y cells. Following a 24-h exposure of cells to DA (final conc., 0.6 mM), we observed a marked increase in apoptosis, increased generation of ROS and decreased cell viability. Pretreatment of the cells for 24 h with spirafolide (0.4, 2, and 10 ?M) before exposure to DA notably increased cell survival (p < 0.01) and lowered intracellular ROS levels (p < 0.01). These results indicate that spirafolide has neuroprotective effects against DA toxicity. These effects may contribute to the treatment of neurodegenerative diseases. PMID:21191760

  8. Deep--elastic scattering and asymptotics

    E-print Network

    S. M. Troshin; N. E. Tyurin

    2012-01-20

    Deep--elastic scattering and its role in discrimination of the possible absorptive and reflective asymptotic scattering mechanisms are discussed with emphasis on the difference in the experimental signatures related to production processes.

  9. Effect of polyphenols on reactive oxygen species production and cell growth of human dermal fibroblasts after irradiation with ultraviolet-A light.

    PubMed

    Shirai, Akihiro; Onitsuka, Masayoshi; Maseda, Hideaki; Omasa, Takeshi

    2015-01-01

    Ultraviolet-A (UV-A) can damage microbes by generating reactive oxygen species (ROS), singlet oxygen, superoxides, hydrogen peroxide and hydroxyl radicals. These species readily react with lipids, proteins, DNA and other constituents of cells, leading to oxidative deterioration and the eventual death of the microbe. However, the oxidative ability of these reactive species also harms the viability of mammalian cells such as fibroblasts and keratinocytes, as they cause both acute and chronic damage, photo-aging, and photo-carcinogenesis. This study describes a UV-A treatment that does not affect the viability or growth of human neonate dermal fibroblasts, as determined by examining the post-irradiation cell density after the addition of polyphenols as antioxidants. The results demonstrate the possible wide applicability of UV-A sterilization. The potency of polyphenols for attenuating UV-A-induced ROS generation in cells was tested using (+)-catechin hydrate, (-)- epigallocatechin gallate hydrate, morin hydrate, quercetin hydrate and resveratrol. The lowest concentration of polyphenols required to reduce ROS by 50% in cells upon exposure to a dose of 15 J cm(-2) was determined and defined as its IC50. Pre-treatment with morin hydrate at its IC50 allowed cells irradiated with 5.0 J cm(-2) UV-A to recover to the level of the specific growth rate of cells incubated without UV-A irradiation. However, the growth rate of cells exposed to 15 J cm(-2) UV-A irradiation was scarcely influenced by co-incubation with morin hydrate; this dose of UV-A also suppressed cell growth completely in the absence of morin hydrate, although co-incubation resulted in no decrease in cell viability. This study demonstrates the potential of polyphenols for protecting both the viability of cells and their ability to proliferate from damage caused by UV-A-irradiation. PMID:25817810

  10. 4-Hydroxy-2-Nonenal, a Reactive Product of Lipid Peroxidation, and Neurodegenerative Diseases: A Toxic Combination Illuminated by Redox Proteomics Studies

    PubMed Central

    Coccia, Raffaella; Butterfield, D. Allan

    2012-01-01

    Abstract Significance: Among different forms of oxidative stress, lipid peroxidation comprises the interaction of free radicals with polyunsaturated fatty acids, which in turn leads to the formation of highly reactive electrophilic aldehydes. Among these, the most abundant aldehydes are 4-hydroxy-2-nonenal (HNE) and malondialdehyde, while acrolein is the most reactive. HNE is considered a robust marker of oxidative stress and a toxic compound for several cell types. Proteins are particularly susceptible to modification caused by HNE, and adduct formation plays a critical role in multiple cellular processes. Recent Advances: With the outstanding progress of proteomics, the identification of putative biomarkers for neurodegenerative disorders has been the main focus of several studies and will continue to be a difficult task. Critical Issues: The present review focuses on the role of lipid peroxidation, particularly of HNE-induced protein modification, in neurodegenerative diseases. By comparing results obtained in different neurodegenerative diseases, it may be possible to identify both similarities and specific differences in addition to better characterize selective neurodegenerative phenomena associated with protein dysfunction. Results obtained in our laboratory and others support the common deregulation of energy metabolism and mitochondrial function in neurodegeneration. Future Directions: Research towards a better understanding of the molecular mechanisms involved in neurodegeneration together with identification of specific targets of oxidative damage is urgently required. Redox proteomics will contribute to broaden the knowledge in regard to potential biomarkers for disease diagnosis and may also provide insight into damaged metabolic networks and potential targets for modulation of disease progression. Antioxid. Redox Signal. 17, 1590–1609. PMID:22114878

  11. Reactive Nitrogen Species Reactivities with Nitrones: Theoretical and Experimental Studies

    PubMed Central

    Nash, Kevin M.; Rockenbauer, Antal; Villamena, Frederick A.

    2012-01-01

    Reactive nitrogen species (RNS) such as nitrogen dioxide (•NO2), peroxynitrite (ONOO–), and nitrosoperoxycarbonate (ONOOCO2–) are among the most damaging species present in biological systems due to their ability to cause modification of key biomolecular systems through oxidation, nitrosylation and nitration. Nitrone spin traps are known to react with free radicals and non-radicals via electrophilic and nucleophilic addition reactions, and have been employed as reagents to detect radicals using electron paramagnetic resonance (EPR) spectroscopy, and as pharmacological agents against oxidative stress-mediated injury. This study examines the reactivity of cyclic nitrones such as 5,5-dimethylpyrroline N-oxide (DMPO) with, •NO2, ONOO–, ONOOCO2–, SNAP and SIN-1 using EPR. The thermochemistries of nitrone reactivity with RNS, and isotropic hfsc's of the addition products were also calculated at the PCM(water)/B3LYP/6-31+G**//B3LYP/6-31G* level of theory with and without explicit water molecules in order to rationalize the nature of the observed EPR spectra. Spin trapping of other RNS such as azide (•N3), nitrogen trioxide (•NO3), amino (•NH2) radicals, and nitroxyl (HNO) were also theoretically and experimentally investigated by EPR spin trapping and mass spectrometry. This study also shows other spin traps such as AMPO, EMPO and DEPMPO can react with radical and non-radical RNS, thus, making spin traps suitable probes as well as antioxidants against RNS mediated oxidative damage. PMID:22775566

  12. Analyzing subvisible particles in protein drug products: a comparison of dynamic light scattering (DLS) and resonant mass measurement (RMM).

    PubMed

    Panchal, Jainik; Kotarek, Joseph; Marszal, Ewa; Topp, Elizabeth M

    2014-05-01

    Aggregation is common in protein drug manufacture, and while the effects of protein particulates are under investigation, many techniques applicable for their characterization have been recently developed. Among the methods available to characterize and quantify protein aggregates, none is applicable over the full size range and different methods often give conflicting results. The studies presented here compare two such methods: dynamic light scattering (DLS) and resonant mass measurement (RMM). The performance of each method was first characterized using polystyrene particle size standards (20, 60, 100, 200, 400, and 1,000 nm) over a range of concentrations. Standard particles were measured both singly and in binary mixtures containing 20 nm particles at a fixed concentration (10(14) particles/mL) and various concentrations of one of the other particle sizes (i.e., 60, 100, 200, 400, or 1,000 nm). DLS and RMM were then used to detect unknown aggregate content in stressed samples of IgG. Both instruments were shown to have a working range that depends on particle size and concentration. In binary mixtures and polydisperse solutions, DLS was able to resolve two species in a manner dependent on both concentration and particle size. RMM was able to resolve particles above 200 nm (150 nm for protein) at concentrations below 10(9) particles/mL. In addition, dilution was evaluated as a technique to confirm and quantify the number of particles in solution. PMID:24570341

  13. bFGF Promotes the Migration of Human Dermal Fibroblasts under Diabetic Conditions through Reactive Oxygen Species Production via the PI3K/Akt-Rac1- JNK Pathways.

    PubMed

    Shi, Hongxue; Cheng, Yi; Ye, Jingjing; Cai, Pingtao; Zhang, Jinjing; Li, Rui; Yang, Ying; Wang, Zhouguang; Zhang, Hongyu; Lin, Cai; Lu, Xianghong; Jiang, Liping; Hu, Aiping; Zhu, Xinbo; Zeng, Qiqiang; Fu, Xiaobing; Li, Xiaokun; Xiao, Jian

    2015-01-01

    Fibroblasts play a pivotal role in the process of cutaneous wound repair, whereas their migratory ability under diabetic conditions is markedly reduced. In this study, we investigated the effect of basic fibroblast growth factor (bFGF) on human dermal fibroblast migration in a high-glucose environment. bFGF significantly increased dermal fibroblast migration by increasing the percentage of fibroblasts with a high polarity index and reorganizing F-actin. A significant increase in intracellular reactive oxygen species (ROS) was observed in dermal fibroblasts under diabetic conditions following bFGF treatment. The blockage of bFGF-induced ROS production by either the ROS scavenger N-acetyl-L-cysteine (NAC) or the NADPH oxidase inhibitor diphenylene iodonium chloride (DPI) almost completely neutralized the increased migration rate of dermal fibroblasts promoted by bFGF. Akt, Rac1 and JNK were rapidly activated by bFGF in dermal fibroblasts, and bFGF-induced ROS production and promoted dermal fibroblast migration were significantly attenuated when suppressed respectively. In addition, bFGF-induced increase in ROS production was indispensable for the activation of focal adhesion kinase (FAK) and paxillin. Therefore, our data suggested that bFGF promotes the migration of human dermal fibroblasts under diabetic conditions through increased ROS production via the PI3K/Akt-Rac1-JNK pathways. PMID:26078726

  14. Climate and topographic controls on simulated pasture production in a semiarid Mediterranean watershed with scattered tree cover

    NASA Astrophysics Data System (ADS)

    Lozano-Parra, J.; Maneta, M. P.; Schnabel, S.

    2014-04-01

    Natural grasses in semiarid rangelands constitute an effective protection against soil erosion and degradation, are a source of natural food for livestock and play a critical role in the hydrologic cycle by contributing to the uptake and transpiration of water. However, natural pastures are threatened by land abandonment and the consequent encroachment of shrubs and trees as well as by changing climatic conditions. In spite of their ecological and economic importance, the spatiotemporal variations of pasture production at the decadal-century scales over whole watersheds are poorly known. We used a physically based, spatially distributed ecohydrologic model applied to a 99.5 ha semiarid watershed in western Spain to investigate the sensitivity of pasture production to climate variability. The ecohydrologic model was run using a 300-year-long synthetic daily climate data set generated using a stochastic weather generator. The data set reproduced the range of climatic variations observed under the current climate. Results indicated that variation of pasture production largely depended on factors that also determined the availability of soil moisture such as the temporal distribution of precipitation, topography, and tree canopy cover. The latter is negatively related with production, reflecting the importance of rainfall and light interception, as well as water consumption by trees. Valley bottoms and flat areas in the lower parts of the catchment are characterized by higher pasture production but more interannual variability. A quantitative assessment of the quality of the simulations showed that ecohydrologic models are a valuable tool to investigate long-term (century scale) water and energy fluxes, as well as vegetation dynamics, in semiarid rangelands.

  15. Measurement of D ± and D 0 production in deep inelastic scattering using a lifetime tag at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Antonioli, P.; Bari, G.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cindolo, F.; Corradi, M.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Antonelli, S.; Basile, M.; Bindi, M.; Cifarelli, L.; Contin, A.; de Pasquale, S.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Nuncio-Quiroz, A. E.; Paul, E.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Kaur, M.; Kaur, P.; Singh, I.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ibrahim, Z. A.; Mohamad Idris, F.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Pawlik, B.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Behnke, O.; Behrens, U.; Blohm, C.; Bonato, A.; Borras, K.; Bot, D.; Ciesielski, R.; Coppola, N.; Fang, S.; Fourletova, J.; Geiser, A.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Hüttmann, A.; Januschek, F.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Lisovyi, M.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Parenti, A.; Rinaldi, L.; Roloff, P.; Rubinsky, I.; Schneekloth, U.; Spiridonov, A.; Szuba, D.; Szuba, J.; Theedt, T.; Ukleja, J.; Wolf, G.; Wrona, K.; Yagües Molina, A. G.; Youngman, C.; Zeuner, W.; Drugakov, V.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Dunne, W.; Forrest, M.; Rosin, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Holm, U.; Klanner, R.; Lohrmann, E.; Perrey, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Stadie, H.; Turcato, M.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Bachynska, O.; Borodin, M.; Kadenko, I.; Kozulia, A.; Libov, V.; Lontkovskyi, D.; Makarenko, I.; Sorokin, Iu.; Verbytskyi, A.; Volynets, O.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Labarga, L.; Del Peso, J.; Ron, E.; Soares, M.; Terrón, J.; Uribe-Estrada, C.; Zambrana, M.; Corriveau, F.; Liu, C.; Schwartz, J.; Walsh, R.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Gladkov, D.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Yu. A.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Abt, I.; Caldwell, A.; Kollar, D.; Reisert, B.; Schmidke, W. B.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Ferrando, J.; Foster, B.; Gwenlan, C.; Horton, K.; Oliver, K.; Robertson, A.; Walczak, R.; Bertolin, A.; Dal Corso, F.; Dusini, S.; Longhin, A.; Stanco, L.; Bellan, P.; Brugnera, R.; Carlin, R.; Garfagnini, A.; Limentani, S.; Oh, B. Y.; Raval, A.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Ingbir, R.; Kananov, S.; Levy, A.; Stern, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Sola, V.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Stewart, T. P.; Boutle, S. K.; Butterworth, J. M.; Hall-Wilton, R.; Jones, T. W.; Loizides, J. H.; Sutton, M. R.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Perlanski, W.; Tymieniecka, T.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Ukleja, A.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Brownson, E.; Reeder, D. D.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.

    2009-09-01

    The production of D ±- and D 0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb-1. The measurements cover the kinematic range 5< Q 2<1000 GeV2, 0.02< y<0.7, 1.5< p {T/ D }<15 GeV and | ? D |<1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F2^{cbar{c}} , to the proton structure function, F 2.

  16. Fusing the vector bosons Higgs Production Through VBF and WW Scattering at the Current and Future LHC

    E-print Network

    Valencic, Nika; Ferrari, P; Hessey, N P

    A long search for the Higgs boson was successfully concluded in the summer of 2012. Ever since, efforts are put into precisely measuring all its properties, its production and decay rates, to verify if this is indeed the particle predicted by the Standard Model (SM) or a first evidence of some New Physics. This thesis describes the search for a specific combination of the Higgs boson production and decay modes which have not been observed so far - the Vector Boson Fusion (VBF) production with the Higgs boson decaying into a pair of W bosons. After the introduction, this thesis is divided into two parts: ‘the first run at the LHC’ and ‘the future runs at the LHC’. The first part describes the theoretical overview of the SM and the Higgs boson in chapters 1 and 2, respectively, followed by the description of the LHC and the ATLAS detector in chapter 3, event and object reconstruction in chapter 4 and the VBF H -> WW analysis in chapters 5 through 7. One of the focuses of this thesis is the treatment of ...

  17. Quantum mechanical calculations of vibrational population inversion in chemical reactions - Numerically exact L-squared-amplitude-density study of the H2Br reactive system

    NASA Technical Reports Server (NTRS)

    Zhang, Y. C.; Zhang, J. Z. H.; Kouri, D. J.; Haug, K.; Schwenke, D. W.

    1988-01-01

    Numerically exact, fully three-dimensional quantum mechanicl reactive scattering calculations are reported for the H2Br system. Both the exchange (H + H-prime Br to H-prime + HBr) and abstraction (H + HBR to H2 + Br) reaction channels are included in the calculations. The present results are the first completely converged three-dimensional quantum calculations for a system involving a highly exoergic reaction channel (the abstraction process). It is found that the production of vibrationally hot H2 in the abstraction reaction, and hence the extent of population inversion in the products, is a sensitive function of initial HBr rotational state and collision energy.

  18. Withaferin A-Caused Production of Intracellular Reactive Oxygen Species Modulates Apoptosis via PI3K/Akt and JNKinase in Rabbit Articular Chondrocytes

    PubMed Central

    2014-01-01

    Withaferin A (WFA) is known as a constituent of Ayurvedic medicinal plant, Withania somnifera, and has been used for thousands of years. Although WFA has been used for the treatment of osteoarthritis (OA) and has a wide range of biochemical and pharmacologic activities, there are no findings suggesting its properties on chondrocytes or cartilage. The aim of the present study is to investigate the effects of WFA on apoptosis with focus on generation of intracellular reactive oxygen species (ROS). Here we showed that WFA significantly increased the generation of intracellular ROS in a dose-dependent manner. We also determined that WFA markedly leads to apoptosis as evidenced by accumulation of p53 by Western blot analysis. N-Acetyl-L-Cystein (NAC), an antioxidant, prevented WFA-caused expression of p53 and inhibited apoptosis of chondrocytes. We also found that WFA causes the activation of PI3K/Akt and JNKinase. Inhibition of PI3K/Akt and JNKinase with LY294002 (LY)/triciribine (TB) or SP600125 (SP) in WFA-treated cells reduced accumulation of p53 and inhibited fragmented DNA. Our findings suggested that apoptosis caused by WFA-induced intracellular ROS generation is regulated through PI3K/Akt and JNKinase in rabbit articular chondrocytes. Graphical Abstract PMID:25120312

  19. Inhibition of NADPH cytochrome P450 reductase by the model sulfur mustard vesicant 2-chloroethyl ethyl sulfide is associated with increased production of reactive oxygen species

    SciTech Connect

    Gray, Joshua P.; Mishin, Vladimir; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

    2010-09-01

    Inhalation of vesicants including sulfur mustard can cause significant damage to the upper airways. This is the result of vesicant-induced modifications of proteins important in maintaining the integrity of the lung. Cytochrome P450s are the major enzymes in the lung mediating detoxification of sulfur mustard and its metabolites. NADPH cytochrome P450 reductase is a flavin-containing electron donor for cytochrome P450. The present studies demonstrate that the sulfur mustard analog, 2-chloroethyl ethyl sulfide (CEES), is a potent inhibitor of human recombinant cytochrome P450 reductase, as well as native cytochrome P450 reductase from liver microsomes of saline and {beta}-naphthoflavone-treated rats, and cytochrome P450 reductase from type II lung epithelial cells. Using rat liver microsomes from {beta}-naphthoflavone-treated rats, CEES was found to inhibit CYP 1A1 activity. This inhibition was overcome by microsomal cytochrome P450 reductase from saline-treated rats, which lack CYP 1A1 activity, demonstrating that the CEES inhibitory activity was selective for cytochrome P450 reductase. Cytochrome P450 reductase also generates reactive oxygen species (ROS) via oxidation of NADPH. In contrast to its inhibitory effects on the reduction of cytochrome c and CYP1A1 activity, CEES was found to stimulate ROS formation. Taken together, these data demonstrate that sulfur mustard vesicants target cytochrome P450 reductase and that this effect may be an important mechanism mediating oxidative stress and lung injury.

  20. Inhibition of NADPH cytochrome P450 reductase by the model sulfur mustard vesicant 2-chloroethyl ethyl sulfide is associated with increased production of reactive oxygen species.

    PubMed

    Gray, Joshua P; Mishin, Vladimir; Heck, Diane E; Laskin, Debra L; Laskin, Jeffrey D

    2010-09-01

    Inhalation of vesicants including sulfur mustard can cause significant damage to the upper airways. This is the result of vesicant-induced modifications of proteins important in maintaining the integrity of the lung. Cytochrome P450s are the major enzymes in the lung mediating detoxification of sulfur mustard and its metabolites. NADPH cytochrome P450 reductase is a flavin-containing electron donor for cytochrome P450. The present studies demonstrate that the sulfur mustard analog, 2-chloroethyl ethyl sulfide (CEES), is a potent inhibitor of human recombinant cytochrome P450 reductase, as well as native cytochrome P450 reductase from liver microsomes of saline and beta-naphthoflavone-treated rats, and cytochrome P450 reductase from type II lung epithelial cells. Using rat liver microsomes from beta-naphthoflavone-treated rats, CEES was found to inhibit CYP 1A1 activity. This inhibition was overcome by microsomal cytochrome P450 reductase from saline-treated rats, which lack CYP 1A1 activity, demonstrating that the CEES inhibitory activity was selective for cytochrome P450 reductase. Cytochrome P450 reductase also generates reactive oxygen species (ROS) via oxidation of NADPH. In contrast to its inhibitory effects on the reduction of cytochrome c and CYP1A1 activity, CEES was found to stimulate ROS formation. Taken together, these data demonstrate that sulfur mustard vesicants target cytochrome P450 reductase and that this effect may be an important mechanism mediating oxidative stress and lung injury. PMID:20561902

  1. Direct mitochondrial dysfunction precedes reactive oxygen species production in amiodarone-induced toxicity in human peripheral lung epithelial HPL1A cells

    SciTech Connect

    Nicolescu, Adrian C. Ji, Yanbin; Comeau, Jeannette L.; Hill, Bruce C.; Takahashi, Takashi; Brien, James F.; Racz, William J.; Massey, Thomas E.

    2008-03-15

    Amiodarone (AM), a drug used in the treatment of cardiac dysrrhythmias, can produce severe pulmonary adverse effects, including fibrosis. Although the pathogenesis of AM-induced pulmonary toxicity (AIPT) is not clearly understood, several hypotheses have been advanced, including increased inflammatory mediator release, mitochondrial dysfunction, and free-radical formation. The hypothesis that AM induces formation of reactive oxygen species (ROS) was tested in an in vitro model relevant for AIPT. Human peripheral lung epithelial HPL1A cells, as surrogates for target cells in AIPT, were susceptible to the toxicity of AM and N-desethylamiodarone (DEA), a major AM metabolite. Longer incubations ({>=} 6 h) of HPL1A cells with 100 {mu}M AM significantly increased ROS formation. In contrast, shorter incubations (2 h) of HPL1A cells with AM resulted in mitochondrial dysfunction and cytoplasmic cytochrome c translocation. Preexposure of HPL1A cells to ubiquinone and {alpha}-tocopherol was more effective than that with Trolox C (registered) or 5,5-dimethylpyrolidine N-oxide (DMPO) at preventing AM cytotoxicity. These data suggest that mitochondrial dysfunction, rather than ROS overproduction, represents an early event in AM-induced toxicity in peripheral lung epithelial cells that may be relevant for triggering AIPT, and antioxidants that target mitochondria may potentially have beneficial effects in AIPT.

  2. Inhibition of NADPH cytochrome P450 reductase by the model sulfur mustard vesicant 2-chloroethyl ethyl sulfide is associated with increased production of reactive oxygen species

    PubMed Central

    Gray, Joshua P.; Mishin, Vladimir; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

    2015-01-01

    Inhalation of vesicants including sulfur mustard can cause significant damage to the upper airways. This is the result of vesicant-induced modifications of proteins important in maintaining the integrity of the lung. Cytochrome P450’s are the major enzymes in the lung mediating detoxification of sulfur mustard and its metabolites. NADPH cytochrome P450 reductase is a flavin-containing electron donor for cytochrome P450. The present studies demonstrate that the sulfur mustard analog, 2-chloroethyl ethyl sulfide (CEES), is a potent inhibitor of human recombinant cytochrome P450 reductase, as well as native cytochrome P450 reductase from liver microsomes of saline and ?-naphthoflavone treated rats, and cytochrome P450 reductase from type II lung epithelial cells. Using rat liver microsomes from ?-naphthoflavone-treated rats, CEES was found to inhibit CYP 1A1 activity. This inhibition was overcome by microsomal cytochrome P450 reductase from saline-treated rats, which lack CYP 1A1 activity, demonstrating that the CEES inhibitory activity was selective for cytochrome P450 reductase. Cytochrome P450 reductase also generates reactive oxygen species (ROS) via oxidation of NADPH. In contrast to its inhibitory effects on the reduction of cytochrome c and CYP1A1 activity, CEES was found to stimulate ROS formation. Taken together, these data demonstrate that sulfur mustard vesicants target cytochrome P450 reductase and that this effect may be an important mechanism mediating oxidative stress and lung injury. PMID:20561902

  3. Effects of uncertainty in SAPRC90 rate constants and selected product yields on reactivity adjustment factors for alternative fuel vehicle emissions. Final report

    SciTech Connect

    Bergin, M.S.; Russell, A.G.; Yang, Y.J.; Milford, J.B.; Kirchner, F.; Stockwell, W.R.

    1996-07-01

    Tropospheric ozone is formed in the atmosphere by a series of reactions involving volatile organic compounds (VOCs) and nitrogen oxides (NO{sub x}). While NOx emissions are primarily composed of only two compounds, nitrogen oxide (NO) and nitrogen dioxide (NO{sub 2}), there are hundreds of different VOCs being emitted. In general, VOCs promote ozone formation, however, the rate and extent of ozone produced by the individual VOCs varies considerably. For example, it is widely acknowledged that formaldehyde (HCHO) is a very reactive VOC, and produces ozone rapidly and efficiently under most conditions. On the other hand, VOCs such as methane, ethane, propane, and methanol do not react as quickly, and are likely to form less urban ozone than a comparable mass of HCHO. The difference in ozone forming potential is one of the bases for the use of alternative fuels. The fuels considered in this study included compressed natural gas, LPG, mixtures of methanol and gasoline, ethanol and gasoline, and a reformulated gasoline.

  4. Skyrmion-Skyrmion Scattering

    E-print Network

    T. Gisiger; M. B. Paranjape

    1993-10-07

    We study the scattering of Skyrmions at low energy and large separation using the method proposed by Manton of truncation to a finite number of degree freedom. We calculate the induced metric on the manifold of the union of gradient flow curves, which for large separation, to first non-trivial order is parametrised by the variables of the product ansatz.

  5. Hydroquinone, a reactive metabolite of benzene, enhances interleukin-4 production in CD4+ T cells and increases immunoglobulin E levels in antigen-primed mice

    PubMed Central

    Lee, M H; Chung, S W; Kang, B Y; Kim, K-M; Kim, T S

    2002-01-01

    Exposure to cigarette smoke is known to increase the risk of the development of allergic disease. The mechanism is not well understood. In this study, we determined the effect of hydroquinone (HQ), a major metabolite of benzene present in large quantities in cigarette tar, on interleukin-4 (IL-4) production by CD4+ T cells. HQ significantly enhanced IL-4 production by keyhole limpet haemocyanin (KLH)-primed CD4+ T cells in a dose-dependent manner. The enhancing effect of HQ on IL-4 production was maximal at a concentration of 50 µm. It increased the level of IL-4 production approximately 10-fold. HQ enhanced IL-4 mRNA expression and also IL-4 gene promoter activity, suggesting that the enhancing effect of HQ on IL-4 production may occur at the transcriptional level. Furthermore, the injection of KLH-primed mice with HQ resulted in a significant increase in the levels of IL-4 and immunoglobulin E. These findings provide evidence that HQ, a major component of cigarette tar, may enhance allergic immune responses by inducing the production of IL-4 in CD4+ T cells. PMID:12153512

  6. Bioinformatic analysis of xenobiotic reactive metabolite target proteins and their interacting partners

    E-print Network

    Hanzlik, Robert P.; Fang, Jianwen; Koen, Yakov M.

    2009-06-12

    Background Protein covalent binding by reactive metabolites of drugs, chemicals and natural products can lead to acute cytotoxicity. Recent rapid progress in reactive metabolite target protein identification has shown that adduction is surprisingly...

  7. Antiplatelet effect of phloroglucinol is related to inhibition of cyclooxygenase, reactive oxygen species, ERK/p38 signaling and thromboxane A{sub 2} production

    SciTech Connect

    Chang, Mei-Chi; Chang, Hsiao-Hua; Chan, Chiu-Po; Chou, Han-Yi; Chang, Bei-En; Yeung, Sin-Yuet; Wang, Tong-Mei; Jeng, Jiiang-Huei

    2012-09-15

    Platelet dysfunction is a major risk factor of cardiovascular diseases such as atherosclerosis, stroke and myocardial infarction. Many antiplatelet agents are used for prevention and treatment of these diseases. In this study, phloroglucinol (2.5–25 ?M) suppressed AA-induced platelet aggregation and thromboxane B{sub 2} (TXB{sub 2}) production, but not U46619-induced platelet aggregation. Phloroglucinol (100–250 ?M) showed little cytotoxicity to platelets. Phloroglucinol inhibited the COX-1 and COX-2 activities by 45–74% and 49–72% respectively at concentrations of 10–50 ?M. At concentrations of 1 and 5 ?M, phloroglucinol attenuated the AA-induced ROS production in platelets by 30% and 53%, with an IC{sub 50} of 13.8 ?M. Phloroglucinol also inhibited the PMA-stimulated ROS production in PMN. Preincubation of platelets by phloroglucinol (10–25 ?M) markedly attenuated the AA-induced ERK and p38 phosphorylation. Intravenous administration of phloroglucinol (2.5 and 5 ?mol/mouse) suppressed the ex vivo AA-induced platelet aggregation by 57–71%. Phloroglucinol administration also elevated the mice tail bleeding time. Moreover, phloroglucinol inhibited the IL-1?-induced PGE{sub 2} production in pulp fibroblasts. These results indicate that antiplatelet and anti-inflammatory effects of phloroglucinol are related to inhibition of COX, ROS and TXA2 production as well as ERK/p38 phosphorylation in platelets. Phloroglucinol further suppress PMA-induced ROS production in PMN. The antiplatelet effect of phloroglucinol was confirmed by ex vivo study. Clinically, the consumption of phloroglucinol-containing food/natural products as nutritional supplement may be helpful to cardiovascular health. Phloroglucinol has potential pharmacological use. -- Highlights: ? Phloroglucinol suppressed AA-induced platelet aggregation and thromboxane production. ? Phloroglucinol inhibited COX activity and IL-1b-induced PGE2 production in fibroblast. ? Phloroglucinol declined platelet and PMN ROS production and ERK/p38 phosphorylation. ? Phloroglucinol suppressed ex vivo AA-induced platelet aggregation. ? Phloroglucinol may prevent and for treatment of atherosclerosis/ vascular diseases.

  8. P2X4 Assembles with P2X7 and Pannexin-1 in Gingival Epithelial Cells and Modulates ATP-induced Reactive Oxygen Species Production and Inflammasome Activation

    PubMed Central

    Johnson, Larry; Atanasova, Kalina Rosenova; Sellami, Hanen; Yilmaz, Özlem; Ojcius, David M.

    2013-01-01

    We have previously reported that Porphyromonas gingivalis infection of gingival epithelial cells (GEC) requires an exogenous danger signal such as ATP to activate an inflammasome and caspase-1, thereby inducing secretion of interleukin (IL)-1?. Stimulation with extracellular ATP also stimulates production of reactive oxygen species (ROS) in GEC. However, the mechanism by which ROS is generated in response to ATP, and the role that different purinergic receptors may play in inflammasome activation, is still unclear. In this study, we revealed that the purinergic receptor P2X4 is assembled with the receptor P2X7 and its associated pore, pannexin-1. ATP induces ROS production through a complex consisting of the P2X4, P2X7, and pannexin-1. P2X7?mediated ROS production can activate the NLRP3 inflammasome and caspase-1. Furthermore, separate depletion or inhibition of P2X4, P2X7, or pannexin-1 complex blocks IL-1? secretion in P. gingivalis-infected GEC following ATP treatment. However, activation via P2X4 alone induces ROS generation but not inflammasome activation. These results suggest that ROS is generated through stimulation of a P2X4/P2X7/pannexin-1 complex, and reveal an unexpected role for P2X4, which acts as a positive regulator of inflammasome activation during microbial infection. PMID:23936165

  9. Polyethylene glycol-coated graphene oxide attenuates antigen-specific IgE production and enhanced antigen-induced T-cell reactivity in ovalbumin-sensitized BALB/c mice

    PubMed Central

    Wu, Hsin-Ying; Lin, Kun-Ju; Wang, Ping-Yen; Lin, Chi-Wen; Yang, Hong-Wei; Ma, Chen-Chi M; Lu, Yu-Jen; Jan, Tong-Rong

    2014-01-01

    Background Graphene oxide (GO) is a promising nanomaterial for potential application in the versatile field of biomedicine. Graphene-based nanomaterials have been reported to modulate the functionality of immune cells in culture and to induce pulmonary inflammation in mice. Evidence pertaining to the interaction between graphene-based nanomaterials and the immune system in vivo remains scarce. The present study investigated the effect of polyethylene glycol-coated GO (PEG-GO) on antigen-specific immunity in vivo. Methods BALB/c mice were intravenously administered with a single dose of PEG-GO (0.5 or 1 mg/kg) 1 hour before ovalbumin (OVA) sensitization, and antigen-specific antibody production and splenocyte reactivity were measured 7 days later. Results Exposure to PEG-GO significantly attenuated the serum level of OVA-specific immunoglobulin E. The production of interferon-? and interleukin-4 by splenocytes restimulated with OVA in culture was enhanced by treatment with PEG-GO. In addition, PEG-GO augmented the metabolic activity of splenocytes restimulated with OVA but not with the T-cell mitogen concanavalin A. Conclusion Collectively, these results demonstrate that systemic exposure to PEG-GO modulates several aspects of antigen-specific immune responses, including the serum production of immunoglobulin E and T-cell functionality. PMID:25228804

  10. Metformin Inhibits the Production of Reactive Oxygen Species from NADH:Ubiquinone Oxidoreductase to Limit Induction of Interleukin-1? (IL-1?) and Boosts Interleukin-10 (IL-10) in Lipopolysaccharide (LPS)-activated Macrophages.

    PubMed

    Kelly, Beth; Tannahill, Gillian M; Murphy, Michael P; O'Neill, Luke A J

    2015-08-14

    Metformin, a frontline treatment for type II diabetes mellitus, decreases production of the pro-form of the inflammatory cytokine IL-1? in response to LPS in macrophages. We found that it specifically inhibited pro-IL-1? production, having no effect on TNF-?. Furthermore, metformin boosted induction of the anti-inflammatory cytokine IL-10 in response to LPS. We ruled out a role for AMP-activated protein kinase (AMPK) in the effect of metformin because activation of AMPK with A769662 did not mimic metformin here. Furthermore, metformin was still inhibitory in AMKP?1- or AMPK?1-deficient cells. The activity of NADH:ubiquinone oxidoreductase (complex I) was inhibited by metformin. Another complex I inhibitor, rotenone, mimicked the effect of metformin on pro-IL-1? and IL-10. LPS induced reactive oxygen species production, an effect inhibited by metformin or rotenone pretreatment. MitoQ, a mitochondrially targeted antioxidant, decreased LPS-induced IL-1? without affecting TNF-?. These results, therefore, implicate complex I in LPS action in macrophages. PMID:26152715

  11. Plumbagin-induced apoptosis in lymphocytes is mediated through increased reactive oxygen species production, upregulation of Fas, and activation of the caspase cascade

    SciTech Connect

    McKallip, Robert J.; Lombard, Catherine; Sun Jingping; Ramakrishnan, Rupal

    2010-08-15

    Extracts from plants containing plumbagin (PLB) continue to be used as a treatment of a number of chronic immunologically-based diseases. However, most of these claims are supported only by anecdotal evidence with few scientific reports describing the mechanism of action or the efficacy of plumbagin in the suppression of the immune response. In the current study, we tested the hypothesis that plumbagin-induced suppression of the immune response was mediated through the induction of apoptosis. Splenocytes from C57BL/6 mice cultured in the presence of 0.5 {mu}M or greater concentrations of PLB significantly reduced proliferative responses to mitogens, including anti-CD3 mAbs, concanavalin A (Con A), lipopolysaccharide (LPS) and staphylococcal enterotoxin B (SEB) in vitro. Exposure of naive and activated splenocytes to PLB led to a significant increase in the levels of apoptosis. In addition, PLB treatment led to a significant increase in the levels of reactive oxygen species (ROS) in naive and activated splenocytes. Furthermore, treatment with the ROS scavenger, N-acetylcysteine (NAC), prevented PLB-induced apoptosis, suggesting a role of ROS in PLB-induced apoptosis. PLB-induced apoptosis led to ROS-mediated activation of both the extrinsic and intrinsic apoptotic pathways. In addition, plumbagin led to increased expression of Fas. Finally, treatment of mice with PLB (5 mg/kg) led to thymic and splenic atrophy as well as a significant suppression of the response to SEB and dinitroflourobenzene (DNFB) in vivo. Together, these results suggest that plumbagin has significant immunosuppressive properties which are mediated by generation of ROS, upregulation of Fas, and the induction of apoptosis.

  12. Fucoidan inhibits proliferation of the SKM-1 acute myeloid leukaemia cell line via the activation of apoptotic pathways and production of reactive oxygen species.

    PubMed

    Wei, Chunmei; Xiao, Qing; Kuang, Xingyi; Zhang, Tao; Yang, Zesong; Wang, Li

    2015-11-01

    Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and a high risk of progression to acute myeloid leukaemia (AML). Fucoidan, a complex sulphated polysaccharide isolated from the cell wall of brown seaweeds, has recently attracted attention for its multiple biological activities and its potential as a novel candidate for cancer therapy. In the present study, the anti?cancer activity of fucoidan was investigated in the MDS/AML cell line SKM?1. Fucoidan inhibited proliferation, induced apoptosis and caused G1-phase arrest of the cell cycle in SKM?1 cells as determined by a cell counting kit 8 assay and flow cytometry. Furthermore, reverse transcription quantitative polymerase chain reaction and western blot analyses indicated that treatment with fucoidan (100 µg/ml for 48 h) activated Fas and caspase?8 in SKM?1 cells, which are critical for the extrinsic apoptotic pathway; furthermore, caspase?9 was activated via decreases in phosphoinositide-3 kinase/Akt signaling as indicated by reduced levels of phosphorylated Akt, suggesting the involvement of the intrinsic apoptotic pathway. In addition, fucoidan treatment of SKM?1 cells resulted in the generation of reactive oxygen species (ROS) as determined by staining with dichloro-dihydro-fluorescein diacetate. These results suggested that the mechanisms of the anti?cancer effects of fucoidan in SKM?1 are closely associated with cell cycle arrest and apoptotic cell death, which partly attributed to the activation of apoptotic pathways and accumulation of intracellular ROS. Our results demonstrated that Fucoidan inhibits proliferation and induces the apoptosis of SKM?1 cells, which provides substantial therapeutic potential for MDS treatment. PMID:26324225

  13. Measurement of charm and beauty production in deep inelastic ep scattering from decays into muons at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Antonioli, P.; Bari, G.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cindolo, F.; Corradi, M.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Antonelli, S.; Basile, M.; Bindi, M.; Cifarelli, L.; Contin, A.; de Pasquale, S.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Nuncio-Quiroz, A. E.; Paul, E.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Brook, N. H.; Heath, G. P.; Morris, J. D.; Kaur, M.; Kaur, P.; Singh, I.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ibrahim, Z. A.; Mohamad Idris, F.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Pawlik, B.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Behnke, O.; Behr, J.; Behrens, U.; Blohm, C.; Borras, K.; Bot, D.; Ciesielski, R.; Coppola, N.; Fang, S.; Geiser, A.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Hüttmann, A.; Januschek, F.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Lisovyi, M.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Parenti, A.; Roloff, P.; Rubinsky, I.; Schneekloth, U.; Spiridonov, A.; Szuba, D.; Szuba, J.; Theedt, T.; Tomaszewska, J.; Wolf, G.; Wrona, K.; Yagües-Molina, A. G.; Youngman, C.; Zeuner, W.; Drugakov, V.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Holm, U.; Klanner, R.; Lohrmann, E.; Perrey, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Stadie, H.; Turcato, M.; Foudas, C.; Fry, C.; Long, K. R.; Tapper, A. D.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Bachynska, O.; Borodin, M.; Kadenko, I.; Kuprash, O.; Libov, V.; Lontkovskyi, D.; Makarenko, I.; Sorokin, Iu.; Verbytskyi, A.; Volynets, O.; Zolko, M.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Del Peso, J.; Ron, E.; Terrón, J.; Uribe-Estrada, C.; Corriveau, F.; Schwartz, J.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Gladkov, D.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Yu. A.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Abt, I.; Caldwell, A.; Kollar, D.; Reisert, B.; Schmidke, W. B.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Allfrey, P. D.; Bell, M. A.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Ferrando, J.; Foster, B.; Gwenlan, C.; Horton, K.; Oliver, K.; Robertson, A.; Walczak, R.; Bertolin, A.; Dal Corso, F.; Dusini, S.; Longhin, A.; Stanco, L.; Brugnera, R.; Carlin, R.; Garfagnini, A.; Limentani, S.; Oh, B. Y.; Raval, A.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cole, J. E.; Hart, J. C.; Abramowicz, H.; Ingbir, R.; Kananov, S.; Levy, A.; Stern, A.; Kuze, M.; Maeda, J.; Hori, R.; Kagawa, S.; Okazaki, N.; Shimizu, S.; Tawara, T.; Hamatsu, R.; Kaji, H.; Kitamura, S.; Ota, O.; Ri, Y. D.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Sola, V.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Stewart, T. P.; Boutle, S. K.; Butterworth, J. M.; Jones, T. W.; Loizides, J. H.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Perlanski, W.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Brownson, E.; Reeder, D. D.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Cui, Y.; Hartner, G.; Menary, S.; Noor, U.; Standage, J.; Whyte, J.; ZEUS Collaboration

    2010-01-01

    The production of charm and beauty quarks in ep interactions has been measured with the ZEUS detector at HERA for squared four-momentum exchange Q 2>20 GeV2, using an integrated luminosity of 126 pb-1. Charm and beauty quarks were identified through their decays into muons. Differential cross sections were measured for muon transverse momenta pT^{?}>1.5 GeV and pseudorapidities -1.6< ? ? <2.3, as a function of pT^{?} , ? ? , Q 2 and Bjorken x. The charm and beauty contributions to the proton structure function F 2 were also extracted. The results agree with previous measurements based on independent techniques and are well described by QCD predictions.

  14. Synthesis of the Four Stereoisomers of 2,3-Epoxy-4-hydroxynonanal, Potential Genotoxic Products of Lipid Peroxidation, and Their Reactivity with Deoxyguanosine

    PubMed Central

    Petrova, Katya V.; Stec, Donald F.; Voehler, Markus; Rizzo, Carmelo J.

    2013-01-01

    2,3-Epoxy-4-hydroxynonanal (EHN) is a potential product of lipid peroxidation that gives rise to genotoxic etheno adducts. We have synthesized all four stereoisomers of EHN and individually reacted them with 2'-deoxyguanosine. In addition to 1,N2-etheno-2'-deoxyguanosine, 12 stereoisomeric products were isolated and characterized by 1H NMR and circular dichroism spectroscopy. The stereochemical assignments were consistent with selective NOE spectra, vicinal coupling constants, and molecular mechanics calculations. Reversed-phase HPLC conditions were developed that could separate most of the adduct mixture. PMID:21258716

  15. MARKETS FOR REACTIVE POWER AND RELIABILITY: A WHITE PAPER

    E-print Network

    1 MARKETS FOR REACTIVE POWER AND RELIABILITY: A WHITE PAPER Engineering and Economics as efficient and optimal production and prices for real and reactive power. The purpose of this paper delivery of electric power. To accomplish this end, the paper opens with specification of an economic

  16. Reactive Power Compensator.

    DOEpatents

    El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

    1992-07-28

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

  17. Reactive power compensator

    DOEpatents

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  18. Reactive modification of polyesters and their blends

    NASA Astrophysics Data System (ADS)

    Wan, Chen

    2004-12-01

    As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring the desired rheological and structural characteristics of the final products for potential applications such as low density extrusion foaming or compatibilization of immiscible polymer blends. Important modification conditions through coagents are identified and reaction mechanisms are proposed. A high MW saturated polyester, PET, can also be rheologically modified in extruders through low MW multifunctional anhydride and epoxy compounds by chain extension/branching. Several such modifiers were successfully screened in terms of their reactivity towards PET under controlled reactive extrusion conditions. A dianhydride with medium reactivity was then successfully used in a one-step reactive modification/extrusion foaming process to produce low density foams. A similar process was successfully used to produce small cell size foams from a four component system containing PET, PP and lesser amounts of a low molecular weight multifunctional epoxy compound and an acid functionalized polyolefin, the latter acting as compatibilizers.

  19. Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass

    E-print Network

    ZEUS collaboration; H. Abramowicz; I. Abt; L. Adamczyk; M. Adamus; R. Aggarwal; S. Antonelli; O. Arslan; V. Aushev; Y. Aushev; O. Bachynska; A. N. Barakbaev; N. Bartosik; O. Behnke; J. Behr; U. Behrens; A. Bertolin; S. Bhadra; I. Bloch; V. Bokhonov; E. G. Boos; K. Borras; I. Brock; R. Brugnera; A. Bruni; B. Brzozowska; P. J. Bussey; A. Caldwell; M. Capua; C. D. Catterall; J. Chwastowski; J. Ciborowski; R. Ciesielski; A. M. Cooper-Sarkar; M. Corradi; F. Corriveau; G. D'Agostini; R. K. Dementiev; R. C. E. Devenish; G. Dolinska; V. Drugakov; S. Dusini; J. Ferrando; J. Figiel; B. Foster; G. Gach; A. Garfagnini; A. Geiser; A. Gizhko; L. K. Gladilin; O. Gogota; Yu. A. Golubkov; J. Grebenyuk; I. Gregor; G. Grzelak; O. Gueta; M. Guzik; W. Hain; G. Hartner; D. Hochman; R. Hori; Z. A. Ibrahim; Y. Iga; M. Ishitsuka; A. Iudin; F. Januschek; I. Kadenko; S. Kananov; T. Kanno; U. Karshon; M. Kaur; P. Kaur; L. A. Khein; D. Kisielewska; R. Klanner; U. Klein; N. Kondrashova; O. Kononenko; Ie. Korol; I. A. Korzhavina; A. Kota?ski; U. Kötz; N. Kovalchuk; H. Kowalski; O. Kuprash; M. Kuze; B. B. Levchenko; A. Levy; V. Libov; S. Limentani; M. Lisovyi; E. Lobodzinska; W. Lohmann; B. Löhr; E. Lohrmann; A. Longhin; D. Lontkovskyi; O. Yu. Lukina; J. Maeda; I. Makarenko; J. Malka; J. F. Martin; S. Mergelmeyer; F. Mohamad Idris; K. Mujkic; V. Myronenko; K. Nagano; A. Nigro; T. Nobe; D. Notz; R. J. Nowak; K. Olkiewicz; Yu. Onishchuk; E. Paul; W. Perla?ski; H. Perrey; N. S. Pokrovskiy; A. S. Proskuryakov; M. Przybycie?; A. Raval; P. Roloff; I. Rubinsky; M. Ruspa; V. Samojlov; D. H. Saxon; M. Schioppa; W. B. Schmidke; U. Schneekloth; T. Schörner-Sadenius; J. Schwartz; L. M. Shcheglova; R. Shehzadi; R. Shevchenko; O. Shkola; I. Singh; I. O. Skillicorn; W. S?omi?ski; V. Sola; A. Solano; A. Spiridonov; L. Stanco; N. Stefaniuk; A. Stern; T. P. Stewart; P. Stopa; J. Sztuk-Dambietz; D. Szuba; J. Szuba; E. Tassi; T. Temiraliev; K. Tokushuku; J. Tomaszewska; A. Trofymov; V. Trusov; T. Tsurugai; M. Turcato; O. Turkot; T. Tymieniecka; A. Verbytskyi; O. Viazlo; R. Walczak; W. A. T. Wan Abdullah; K. Wichmann; M. Wing; G. Wolf; S. Yamada; Y. Yamazaki; N. Zakharchuk; A. F. ?arnecki; L. Zawiejski; O. Zenaiev; B. O. Zhautykov; N. Zhmak; D. S. Zotkin

    2014-10-21

    The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q^2 < 1000 GeV^2 using an integrated luminosity of 354 pb^{-1}. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q^2, Bjorken x, jet transverse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q^2. The running beauty-quark mass, m_b at the scale m_b, was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be 4.07 \\pm 0.14 (fit} ^{+0.01}_{-0.07} (mod.) ^{+0.05}_{-0.00} (param.) ^{+0.08}_{-0.05} (theo) GeV.

  20. Chemical Imaging and Dynamical Studies of Reactivity and Emergent Behavior in Complex Interfacial Systems. Final Technical Report

    SciTech Connect

    Sibener, Steven J.

    2014-03-11

    This research program explored the efficacy of using molecular-level manipulation, imaging and scanning tunneling spectroscopy in conjunction with supersonic molecular beam gas-surface scattering to significantly enhance our understanding of chemical processes occurring on well-characterized interfaces. One program focus was on the spatially-resolved emergent behavior of complex reaction systems as a function of the local geometry and density of adsorbate-substrate systems under reaction conditions. Another focus was on elucidating the emergent electronic and related reactivity characteristics of intentionally constructed single and multicomponent atom- and nanoparticle-based materials. We also examined emergent chirality and self-organization in adsorbed molecular systems where collective interactions between adsorbates and the supporting interface lead to spatial symmetry breaking. In many of these studies we combined the advantages of scanning tunneling (STM) and atomic force (AFM) imaging, scanning tunneling local electronic spectroscopy (STS), and reactive supersonic molecular beams to elucidate precise details of interfacial reactivity that had not been observed by more traditional surface science methods. Using these methods, it was possible to examine, for example, the differential reactivity of molecules adsorbed at different bonding sites in conjunction with how reactivity is modified by the local configuration of nearby adsorbates. At the core of this effort was the goal of significantly extending our understanding of interfacial atomic-scale interactions to create, with intent, molecular assemblies and materials with advanced chemical and physical properties. This ambitious program addressed several key topics in DOE Grand Challenge Science, including emergent chemical and physical properties in condensed phase systems, novel uses of chemical imaging, and the development of advanced reactivity concepts in combustion and catalysis including carbon management. These activities directly benefitted national science objectives in the areas of chemical energy production and advanced materials development.

  1. Enhanced production of reactive oxygen species by gadolinium oxide nanoparticles under core-inner-shell excitation by proton or monochromatic X-ray irradiation: implication of the contribution from the interatomic de-excitation-mediated nanoradiator effect to dose enhancement.

    PubMed

    Seo, Seung-Jun; Han, Sung-Mi; Cho, Jae-Hoon; Hyodo, Kazuyuki; Zaboronok, Alexander; You, He; Peach, Ken; Hill, Mark A; Kim, Jong-Ki

    2015-11-01

    Core-inner-valence ionization of high-Z nanoparticle atomic clusters can de-excite electrons through various interatomic de-excitation processes, thereby leading to the ionization of both directly exposed atoms and adjacent neutral atoms within the nanoparticles, and to an enhancement in photon-electron emission, which is termed the nanoradiator effect. To investigate the nanoradiator-mediated dose enhancement in the radio-sensitizing of high-Z nanoparticles, the production of reactive oxygen species (ROS) was measured in a gadolinium oxide nanoparticle (Gd-oxide NP) solution under core-inner-valence excitation of Gd with either 50 keV monochromatic synchrotron X-rays or 45 MeV protons. This measurement was compared with either a radiation-only control or a gadolinium-chelate magnetic resonance imaging contrast agent solution containing equal amounts of gadolinium as the separate atomic species in which Gd-Gd interatomic de-excitations are absent. Ionization excitations followed by ROS measurements were performed on nanoparticle-loaded cells or aqueous solutions. Both photoexcitation and proton impact produced a dose-dependent enhancement in the production of ROS by a range of factors from 1.6 to 1.94 compared with the radiation-only control. Enhanced production of ROS, by a factor of 1.83, was observed from Gd-oxide NP atomic clusters compared with the Gd-chelate molecule, with a Gd concentration of 48 ?g/mL in the core-level photon excitation, or by a factor of 1.82 under a Gd concentration of 12 ?g/mL for the proton impact at 10 Gy (p < 0.02). The enhanced production of ROS in the irradiated nanoparticles suggests the potential for additional therapeutic dose enhancements in radiation treatment via the potent Gd-Gd interatomic de-excitation-driven nanoradiator effect. PMID:26242374

  2. Reactive molecular dynamics simulations of shocked PETN

    NASA Astrophysics Data System (ADS)

    Budzien, Joanne; Thompson, Aidan P.; Zybin, Sergey V.

    2008-03-01

    We have performed molecular dynamics simulations of PETN crystals subjected to shock along the [100] direction. Using the reactive forcefield, ReaxFF, and the molecular dynamics code, GRASP, allows us to track the chemical reactions that occur as both a function of time and position. By simulating larger systems, we can observe the formation of both primary and secondary products to make comparisons with experiments. Composition profiles of these products will be shown along with profiles of stress, temperature, and potential energy.

  3. SHIP-1 Couples to the Dectin-1 hemITAM and Selectively Modulates Reactive Oxygen Species Production in Dendritic Cells in Response to Candida albicans.

    PubMed

    Blanco-Menéndez, Noelia; Del Fresno, Carlos; Fernandes, Sandra; Calvo, Enrique; Conde-Garrosa, Ruth; Kerr, William G; Sancho, David

    2015-11-01

    Dectin-1 (Clec7a) is a paradigmatic C-type lectin receptor that binds Syk through a hemITAM motif and couples sensing of pathogens such as fungi to induction of innate responses. Dectin-1 engagement triggers a plethora of activating events, but little is known about the modulation of such pathways. Trying to define a more precise picture of early Dectin-1 signaling, we explored the interactome of the intracellular tail of the receptor in mouse dendritic cells. We found unexpected binding of SHIP-1 phosphatase to the phosphorylated hemITAM. SHIP-1 colocalized with Dectin-1 during phagocytosis of zymosan in a hemITAM-dependent fashion. Moreover, endogenous SHIP-1 relocated to live or heat-killed Candida albicans-containing phagosomes in a Dectin-1-dependent manner in GM-CSF-derived bone marrow cells (GM-BM). However, SHIP-1 absence in GM-BM did not affect activation of MAPK or production of cytokines and readouts dependent on NF-?B and NFAT. Notably, ROS production was enhanced in SHIP-1-deficient GM-BM treated with heat-killed C. albicans, live C. albicans, or the specific Dectin-1 agonists curdlan or whole glucan particles. This increased oxidative burst was dependent on Dectin-1, Syk, PI3K, phosphoinositide-dependent protein kinase 1, and NADPH oxidase. GM-BM from CD11c?SHIP-1 mice also showed increased killing activity against live C. albicans that was dependent on Dectin-1, Syk, and NADPH oxidase. These results illustrate the complexity of myeloid C-type lectin receptor signaling, and how an activating hemITAM can also couple to intracellular inositol phosphatases to modulate selected functional responses and tightly regulate processes such as ROS production that could be deleterious to the host. PMID:26416276

  4. Salt stress-induced production of reactive oxygen- and nitrogen species and cell death in the ethylene receptor mutant Never ripe and wild type tomato roots.

    PubMed

    Poór, Péter; Kovács, Judit; Borbély, Péter; Takács, Zoltán; Szepesi, Ágnes; Tari, Irma

    2015-12-01

    The salt stress triggered by sublethal, 100 mM and lethal, 250 mM NaCl induced ethylene production as well as rapid accumulation of superoxide radical and H2O2 in the root tips of tomato (Solanum lycopersicum cv. Ailsa Craig) wild type and ethylene receptor mutant, Never ripe (Nr/Nr) plants. In the wild type plants superoxide accumulation confined to lethal salt concentration while H2O2 accumulated more efficiently under sublethal salt stress. However, in Nr roots the superoxide production was higher and unexpectedly, H2O2 level was lower than in the wild type under sublethal salt stress. Nitric oxide production increased significantly under sublethal and lethal salt stress in both genotypes especially in mutant plants, while peroxynitrite accumulated significantly under lethal salt stress. Thus, the nitro-oxidative stress may be stronger in Nr roots, which leads to the programmed death of tissues, characterized by the DNA and protein degradation and loss of cell viability under moderate salt stress. In Nr mutants the cell death was induced in the absence of ethylene perception. Although wild type roots could maintain their potassium content under moderate salt stress, K(+) level significantly declined leading to small K(+)/Na(+) ratio in Nr roots. Thus Nr mutants were more sensitive to salt stress than the wild type and the viability of root cells decreased significantly under moderate salt stress. These changes can be attributed to a stronger ionic stress due to the K(+) loss from the root tissues. PMID:26512971

  5. Astrocyte-targeted production of IL-10 induces changes in microglial reactivity and reduces motor neuron death after facial nerve axotomy.

    PubMed

    Villacampa, Nàdia; Almolda, Beatriz; Vilella, Antonietta; Campbell, Iain L; González, Berta; Castellano, Bernardo

    2015-07-01

    Interleukin-10 (IL-10) is a cytokine that plays a crucial role in regulating the inflammatory response and immune reactions. In the central nervous system (CNS), IL-10 is mainly produced by astrocytes and microglia and it is upregulated after various insults, such as experimental autoimmune encephalomyelitis, middle cerebral artery occlusion, excitotoxicity and traumatic brain injury. To better understand the effects of IL-10 in the normal and injured CNS, we generated transgenic mice (termed GFAP-IL-10Tg) that expressed the murine IL-10 gene under the transcriptional control of the glial fibrillary acidic protein (GFAP) promoter. Previous studies demonstrated marked changes in the microglial phenotype in these mice under basal conditions. The objective of the present study was to investigate the effects of local astrocyte-targeted IL-10 production on glial activation, neuronal degeneration and leukocyte recruitment after axotomy. GFAP-IL-10Tg mice had marked changes in the phenotype of activated microglial cells, as well as in the number of microglial clusters and in microglial cell density. These microglial changes are accompanied by a twofold increase in lymphocyte infiltration in GFAP-IL-10Tg mice and around twofold decrease in neuronal cell death at 21 dpi. Altogether, our findings suggested that astrocyte-targeted production of IL-10 impacted the microglial response and lymphocyte recruitment and culminated in a beneficial effect on neuronal survival. PMID:25691003

  6. Initiator Effects in Reactive Extrusion of Starch Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch with water-soluble polymers such as polyacrylamide have potential applications including hydrogels, superabsorbents, and thickening agents. Reactive extrusion is a rapid, continuous method for production of starch graft copolymers with high reaction and grafting efficienc...

  7. Reactive Power Compensating System.

    DOEpatents

    Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

    1985-01-04

    The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

  8. Reactive power compensating system

    DOEpatents

    Williams, Timothy J. (Redondo Beach, CA); El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Seattle, WA)

    1987-01-01

    The reactive power of an induction machine is compensated by providing fixed capacitors on each phase line for the minimum compensation required, sensing the current on one line at the time its voltage crosses zero to determine the actual compensation required for each phase, and selecting switched capacitors on each line to provide the balance of the compensation required.

  9. What Is Reactive Arthritis?

    MedlinePLUS

    ... NIAMS publication. To order Reactive Arthritis Q&A full-text version, please contact NIAMS using the contact information ... nih.gov Website: http://www.niams.nih.gov Full NIAMS Site NIH… Turning Discovery Into Health ® ... Comments Moderation Policy Site Map | Viewers and Players

  10. Guidance Document Reactive Chemicals

    E-print Network

    -sensitive Materials: Shock-sensitive materials are explosive and are sensitive to heat or shock. Examples include dry picric acid, fulminates, dry benzoyl peroxide, ammonium perchlorate, and compounds with functional groups of water-reactive materials include alkali metals (Li, Na, K), silanes, anhydrous aluminum chloride

  11. Gypenosides attenuate cholesterol-induced DNA damage by inhibiting the production of reactive oxygen species in human umbilical vein endothelial cells.

    PubMed

    Quan, Yuan; Yang, Yijun; Wang, Huixing; Shu, Bo; Gong, Qi-Hai; Qian, Minzhang

    2015-04-01

    Previous studies have demonstrated that DNA damage induces atherosclerosis and that oxidative stress has an important role in DNA damage. Gypenosides (Gps), the main ingredient of Gynostemma Pentaphylla (Thunb.) Makino, have been recognized as specific antioxidants and have previously been reported to inhibit high?fat diet?induced atherosclerosis in rats. However, whether or not Gps attenuate DNA damage through their antioxidant effects remains to be elucidated. The current study was performed to clarify whether or not Gps can inhibit cholesterol?induced DNA damage through antioxidation. The present study provided new insights into the pharmacological effects of Gps on atherosclerosis. HUVECs were treated with Gps at various concentrations (1, 10 and 100 µg/ml) for 1 h. The protective effects of Gps on cholesterol?induced DNA damage were determined using immunofluorescence, western blotting, reverse?transcription quantitative polymerase chain reaction and flow cytometry. Pretreatment with Gps (1, 10 and 100 µg/ml) effectively attenuated cholesterol?induced DNA damage in HUVECs by inhibiting phosphorylation of H2AX, a member of the histone family. Furthermore, Gps (100 µg/ml) pretreatment inhibited cholesterol?induced transcription and activity of nicotinamide adenine dinucleotide phosphate?oxidase 4 and reduced intracellular ROS levels. In conclusion, Gps attenuated cholesterol?induced DNA damage by inhibiting ROS production in HUVECs, suggesting that the inhibitory effect of Gps on atherogenesis is correlated with the alleviation of DNA damage. PMID:25515035

  12. Impact of Particle Aggregation on Nanoparticle Reactivity

    NASA Astrophysics Data System (ADS)

    Jassby, David

    2011-12-01

    The prevalence of nanoparticles in the environment is expected to grow in the coming years due to their increasing pervasiveness in consumer and industrial applications. Once released into the environment, nanoparticles encounter conditions of pH, salinity, UV light, and other solution conditions that may alter their surface characteristics and lead to aggregation. The unique properties that make nanoparticles desirable are a direct consequence of their size and increased surface area. Therefore, it is critical to recognize how aggregation alters the reactive properties of nanomaterials, if we wish to understand how these properties are going to behave once released into the environment. The size and structure of nanoparticle aggregates depend on surrounding conditions, including hydrodynamic ones. Depending on these conditions, aggregates can be large or small, tightly packed or loosely bound. Characterizing and measuring these changes to aggregate morphology is important to understanding the impact of aggregation on nanoparticle reactive properties. Examples of decreased reactivity due to aggregation include the case where tightly packed aggregates have fewer available surface sites compared to loosely packed ones; also, photocatalytic particles embedded in the center of large aggregates will experience less light when compared to particles embedded in small aggregates. However, aggregation also results in an increase in solid-solid interfaces between nanoparticles. This can result in increased energy transfer between neighboring particles, surface passivation, and altered surface tension. These phenomena can lead to an increase in reactivity. The goal of this thesis is to examine the impacts of aggregation on the reactivity of a select group of nanomaterials. Additionally, we examined how aggregation impacts the removal efficiency of fullerene nanoparticles using membrane filtration. The materials we selected to study include ZnS---a metal chalcogenide nanoparticle that photoluminesces after exposure to UV; TiO2 and ZnO nanoparticles---photocatalytic nanoparticles that generate reactive oxygen species upon UV irradition; and, fullerene nanoparticles used in the filtration experiments, selected for their potential use, small size, and surface chemistry. Our primary methods used to characterize particle and aggregate characteristics include dynamic light scattering used to describe particle size, static light scattering used to characterize aggregate structure (fractal dimension), transmission electron microscopy used to verify primary particle sizes, and electrophoretic mobility measurements to evaluate suspension stability. The reactive property of ZnS that was measured as a function of aggregation was photoluminescence, which was measured using a spectrofluorometer. The reactive property of TiO2 and ZnO that was studied was their ability to generate hydroxyl radicals; these were measured by employing a fluorescent probe that becomes luminescent upon interaction with the hydroxyl radical. To detect the presence of fullerene nanoparticles and calculate removal efficiencies, we used total organic carbon measurements. Additionally, we used UV-vis spectroscopy to approximate the impact of particle shadowing in TiO2 and ZnO aggregates, and Fourier transformed infrared spectroscopy to determine how different electrolytes interact with fullerene surface groups. Our findings indicate that the impact of aggregation on nanoparticle reactivity is material specific. ZnS nanoparticles exhibit a 2-fold increase in band-edge photoluminescence alongside a significant decrease in defect-site photoluminescence. This is attributed to aggregate size-dependent surface tension. Additionally, we used photoluminescence measurements to develop a new method for calculating the critical coagulation concentration of a nanoparticle suspension. The ability of both TiO2 and ZnO to generate hydroxyl radicals was significantly hampered by aggregation. The decline in hydroxyl radical generation could be attributed to two key parameters. First, increas

  13. Measurement of “pretzelosity” asymmetry of charged pion production in semi-inclusive deep inelastic scattering on a polarized He3 target

    SciTech Connect

    Zhang, Y.; Qian, X.; Allada, K.; Dutta, C.; Huang, J.; Katich, J.; Wang, Y.; Aniol, K.; Annand, J. R. M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. -P.; Chen, W.; Chirapatpimol, K.; Chudakov, E.; Cisbani, E.; Cornejo, J. C.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; De Leo, R.; Deng, X.; Deur, A.; Ding, H.; Dolph, P. A. M.; Dutta, D.; El Fassi, L.; Frullani, S.; Gao, H.; Garibaldi, F.; Gaskell, D.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Guo, L.; Hamilton, D.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, M.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Jin, G.; Jones, M. K.; Kelleher, A.; Kim, W.; Kolarkar, A.; Korsch, W.; LeRose, J. J.; Li, X.; Li, Y.; Lindgren, R.; Liyanage, N.; Long, E.; Lu, H. -J.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; McNulty, D.; Meziani, Z. -E.; Michaels, R.; Moffit, B.; Muñoz Camacho, C.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Oh, Y.; Osipenko, M.; Parno, D.; Peng, J. C.; Phillips, S. K.; Posik, M.; Puckett, A. J. R.; Qiang, Y.; Rakhman, A.; Ransome, R. D.; Riordan, S.; Saha, A.; Sawatzky, B.; Schulte, E.; Shahinyan, A.; Shabestari, M. H.; Širca, S.; Stepanyan, S.; Subedi, R.; Sulkosky, V.; Tang, L. -G.; Tobias, W. A.; Urciuoli, G. M.; Vilardi, I.; Wang, K.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Ye, Y.; Ye, Z.; Yuan, L.; Zhan, X.; Zhang, Y. -W.; Zhao, B.; Zheng, X.; Zhu, L.; Zhu, X.; Zong, X.

    2014-11-24

    An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized ³He target was performed at Jefferson Lab in the kinematic region of 0.16 < x < 0.35 and 1.4 < Q² < 2.7 GeV². Our results show that both ?± on 3He and on neutron pretzelosity asymmetries are consistent with zero within experimental uncertainties.

  14. Meaurement of D{sup *}{sup plus_minus} production in deep inelastic e{sup plus_minus}p scattering at HERA.

    SciTech Connect

    Chekanov, S.; Derrick, M.; Krakauer, D.; Loizides, J. H.; Magill, S.; Musgrave, B.; Repond, J.; Yoshida, R.; ZEUS Collaboration; High Energy Physics

    2004-01-01

    Inclusive production of D{sup *}{sup {+-}} (2010) mesons in deep inelastic scattering has been measured with the ZEUS detector at DESY HERA using an integrated luminosity of 81.9 pb{sup -1}. The decay channel D{sup *}{sup +}{yields}D0{pi}{sup +} with D0{yields}K-{pi}{sup +} and corresponding antiparticle decay were used to identify D{sup *} mesons. Differential D{sup *} cross sections with 1.5

  15. PREDICTING CHEMICAL REACTIVITY BY COMPUTER

    EPA Science Inventory

    Mathematical models for predicting the fate of pollutants in the environment require reactivity parameter values--that it, the physical and chemical constants that govern reactivity. lthough empirical structure-activity relationships have been developed that allow estimation of s...

  16. Cutting edge: direct interaction of TLR4 with NAD(P)H oxidase 4 isozyme is essential for lipopolysaccharide-induced production of reactive oxygen species and activation of NF-kappa B.

    PubMed

    Park, Hye Sun; Jung, Hye Young; Park, Eun Young; Kim, Jaesang; Lee, Won Jae; Bae, Yun Soo

    2004-09-15

    LPS, the primary constituent of the outer membrane of Gram-negative bacteria, is recognized by TLR4. Binding of TLR4 to LPS triggers various cell signaling pathways including NF-kappaB activation and reactive oxygen species (ROS) production. In this study, we present the data that LPS-induced ROS generation and NF-kappaB activation are mediated by a direct interaction of TLR4 with (NAD(P)H oxidase 4 (Nox) 4), a protein related to gp91phox (Nox2) of phagocytic cells, in HEK293T cells. Yeast two hybrid and GST pull-down assays indicated that the COOH-terminal region of Nox4 interacted with the cytoplasmic tail of TLR4. Knockdown of Nox4 by transfection of small interference RNA specific to the Nox4 isozyme in HEK293T cells expressing TLR4 along with MD2 and CD14 resulted in inhibition of LPS-induced ROS generation and NF-kappaB activation. Taken together, these results indicate that direct interaction of TLR4 with Nox4 is involved in LPS-mediated ROS generation and NF-kappaB activation. PMID:15356101

  17. The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2

    PubMed Central

    Maioli, N.A.; Zarpelon, A.C.; Mizokami, S.S.; Calixto-Campos, C.; Guazelli, C.F.S.; Hohmann, M.S.N.; Pinho-Ribeiro, F.A.; Carvalho, T.T.; Manchope, M.F.; Ferraz, C.R.; Casagrande, R.; Verri, W.A.

    2015-01-01

    It is currently accepted that superoxide anion (O2 •?) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment. PMID:25714890

  18. Immune reactivity to food coloring.

    PubMed

    Vojdani, Aristo; Vojdani, Charlene

    2015-01-01

    Artificial food dyes are made from petroleum and have been approved by the US Food and Drug Administration (FDA) for the enhancement of the color of processed foods. They are widely used in the food and pharmaceutical industries to increase the appeal and acceptability of their products. Synthetic food colorants can achieve hues not possible for natural colorants and are cheaper, more easily available, and last longer. However, since the use of artificial food coloring has become widespread, many allergic and other immune reactive disorders have increasingly been reported. During the past 50 y, the amount of synthetic dye used in foods has increased by 500%. Simultaneously, an alarming rise has occurred in behavioral problems in children, such as aggression, attention deficit disorder (ADD), and attention-deficit/hyperactivity disorder (ADHD). The ingestion of food delivers the greatest foreign antigenic load that challenges the immune system. Artificial colors can also be absorbed via the skin through cosmetic and pharmaceutical products. The molecules of synthetic colorants are small, and the immune system finds it difficult to defend the body against them. They can also bond to food or body proteins and, thus, are able to act in stealth mode to circumvent and disrupt the immune system. The consumption of synthetic food colors, and their ability to bind with body proteins, can have significant immunological consequences. This consumption can activate the inflammatory cascade, can result in the induction of intestinal permeability to large antigenic molecules, and could lead to cross-reactivities, autoimmunities, and even neurobehavioral disorders. The Centers for Disease Control (CDC) recently found a 41% increase in diagnoses of ADHD in boys of high-school age during the past decade. More shocking is the legal amount of artificial colorants allowed by the FDA in the foods, drugs, and cosmetics that we consume and use every day. The consuming public is largely unaware of the perilous truth behind the deceptive allure of artificial color. PMID:25599186

  19. Peptide template effects on the synthesis and reactivity of metal nanoparticle networks

    NASA Astrophysics Data System (ADS)

    Bhandari, Rohit

    A bio-templated approach for the synthesis of multiple inorganic materials has been presented that correlates with the role of a 3-dimensional peptide template in controlling the overall reactivity of the fabricated materials for a variety of chemical reactions. The role of self-assembling R5 peptide for the formation of metallic nanoparticles including Pd, Au and Pt has been described. The materials were fully characterized using UV-vis spectroscopy, dynamic light scattering analysis, transmission electron microscopy and powder-X ray diffraction analysis. Also, the materials were employed as efficient catalysts for the Stille coupling reaction, 4-nitrophenol reduction as well as olefin hydrogenation reactions. These results are important as these template-based materials could potentially serve as candidates for a variety of applications ranging from bio- sensing tocatalysis to energy production.

  20. Low-energy ion beamline scattering apparatus for surface science investigations

    SciTech Connect

    Gordon, M.J.; Giapis, K.P.

    2005-08-15

    We report on the design, construction, and performance of a high current (monolayers/s), mass-filtered ion beamline system for surface scattering studies using inert and reactive species at collision energies below 1500 eV. The system combines a high-density inductively coupled plasma ion source, high-voltage floating beam transport line with magnet mass-filter and neutral stripping, decelerator, and broad based detection capabilities (ions and neutrals in both mass and energy) for products leaving the target surface. The entire system was designed from the ground up to be a robust platform to study ion-surface interactions from a more global perspective, i.e., high fluxes (>100 {mu}A/cm{sup 2}) of a single ion species at low, tunable energy (50-1400{+-}5 eV full width half maximum) can be delivered to a grounded target under ultrahigh vacuum conditions. The high current at low energy problem is solved using an accel-decel transport scheme where ions are created at the desired collision energy in the plasma source, extracted and accelerated to high transport energy (20 keV to fight space charge repulsion), and then decelerated back down to their original creation potential right before impacting the grounded target. Scattered species and those originating from the surface are directly analyzed in energy and mass using a triply pumped, hybrid detector composed of an electron impact ionizer, hemispherical electrostatic sector, and rf/dc quadrupole in series. With such a system, the collision kinematics, charge exchange, and chemistry occurring on the target surface can be separated by fully analyzing the scattered product flux. Key design aspects of the plasma source, beamline, and detection system are emphasized here to highlight how to work around physical limitations associated with high beam flux at low energy, pumping requirements, beam focusing, and scattered product analysis. Operational details of the beamline are discussed from the perspective of available beam current, mass resolution, projectile energy spread, and energy tunability. As well, performance of the overall system is demonstrated through three proof-of-concept examples: (1) elastic binary collisions at low energy (2) core-level charge exchange reactions involving {sup 20}Ne{sup +} with Mg/Al/Si/P targets, and (3) reactive scattering of CF{sub 2}{sup +}/CF{sub 3}{sup +} off Si. These studies clearly demonstrate why low, tunable incident energy, as well as mass and energy filtering of products leaving the target surface is advantageous and often essential for studies of inelastic energy losses, hard-collision charge exchange, and chemical reactions that occur during ion-surface scattering.

  1. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  2. Multifunctional reactive nanocomposite materials

    NASA Astrophysics Data System (ADS)

    Stamatis, Demitrios

    Many multifunctional nanocomposite materials have been developed for use in propellants, explosives, pyrotechnics, and reactive structures. These materials exhibit high reaction rates due to their developed reaction interfacial area. Two applications addressed in this work include nanocomposite powders prepared by arrested reactive milling (ARM) for burn rate modifiers and reactive structures. In burn rate modifiers, addition of reactive nanocomposite powders to aluminized propellants increases the burn rate of aluminum and thus the overall reaction rate of an energetic formulation. Replacing only a small fraction of aluminum by 8Al·MoO3 and 2B·Ti nanocomposite powders enhances the reaction rate with little change to the thermodynamic performance of the formulation; both the rate of pressure rise and maximum pressure measured in the constant volume explosion test increase. For reactive structures, nanocomposite powders with bulk compositions of 8Al·MoO3, 12Al·MoO3, and 8Al·3CuO were prepared by ARM and consolidated using a uniaxial die. Consolidated samples had densities greater than 90% of theoretical maximum density while maintaining their high reactivity. Pellets prepared using 8Al·MoO3 powders were ignited by a CO2 laser. Ignition delays increased at lower laser powers and greater pellet densities. A simplified numerical model describing heating and thermal initiation of the reactive pellets predicted adequately the observed effects of both laser power and pellet density on the measured ignition delays. To investigate the reaction mechanisms in nanocomposite thermites, two types of nanocomposite reactive materials with the same bulk compositions 8Al·MoO3 were prepared by different methods. One of the materials was manufactured by ARM and the other, so called metastable interstitial composite (MIC), by mixing of nano-scaled individual powders. Clear differences in the low-temperature redox reactions, welldetectable by differential scanning calorimetry (DSC), were established between MIC and ARM-prepared materials. However, the materials behaved similarly to each other in the ignition experiments. It is proposed that the ignition of both MIC and ARM-prepared materials at the same temperature can be explained by a thermodynamically driven transformation of a protective amorphous alumina into a crystalline polymorph. Low temperature redox reactions in ARM-prepared Al-CuO nanocomposites were characterized using DSC and isothermal microcalorimetry. The results were interpreted using a Cabrera-Mott reaction model. Simultaneous processing of both experimental data sets identified the parameters for the respective Cabrera-Mott kinetics. The low temperature kinetic model was coupled with a multi-step oxidation model describing diffusion-controlled growth of amorphous and gamma-Al2O3 polymorphs. The kinetic parameters for the multistep oxidation model from previous research were adjusted based on DSC measurements. The combined heterogeneous reactions model was used to interpret results of ignition experiments. It is proposed that the heterogeneous reactions considered serve as ignition triggers and ensuing gas release processes contributes to additional heat release and temperature runaway.

  3. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidi none to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  4. Reactive Air Aluminization

    SciTech Connect

    Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.

    2011-10-28

    Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.

  5. Skylab reactivation mission report

    NASA Technical Reports Server (NTRS)

    Chubb, W. B.

    1980-01-01

    On July 11, 1979, Skylab impacted the Earth's surface. The debris dispersion area stretched from the South Eastern Indian Ocean across a sparsely populated section of Western Australia. The events leading to the reentry of Skylab are discussed and a final assessment of the Skylab debris impact footprint is presented. Also included are detailed evaluations of the various Skylab systems that were reactivated when control of Skylab was regained in mid-1978 after having been powered down since February 4, 1974.

  6. Becoming Reactive by Concretization

    NASA Technical Reports Server (NTRS)

    Prieditis, Armand; Janakiraman, Bhaskar

    1992-01-01

    One way to build a reactive system is to construct an action table indexed by the current situation or stimulus. The action table describes what course of action to pursue for each situation or stimulus. This paper describes an incremental approach to constructing the action table through achieving goals with a hierarchical search system. These hierarchies are generated with transformations called concretizations, which add constraints to a problem and which can reduce the search space. The basic idea is that an action for a state is looked up in the action table and executed whenever the action table has an entry for that state; otherwise, a path is found to the nearest (cost-wise in a graph with costweighted arcs) state that has a mappring from a state in the next highest hierarchy. For each state along the solution path, the successor state in the path is cached in the action table entry for that state. Without caching, the hierarchical search system can logarithmically reduce search. When the table is complete the system no longer searches: it simply reacts by proceeding to the state listed in the table for each state. Since the cached information is specific only to the nearest state in the next highest hierarchy and not the goal, inter-goal transfer of reactivity is possible. To illustrate our approach, we show how an implemented hierarchical search system can completely reactive.

  7. Analysis of HSV viral reactivation in explants of sensory neurons

    PubMed Central

    Turner, Anne-Marie W.; Kristie, Thomas M.

    2014-01-01

    As with all Herpesviruses, Herpes simplex virus (HSV) has both a lytic replication phase and a latency-reactivation cycle. During lytic replication, there is an ordered cascade of viral gene expression that leads to the synthesis of infectious viral progeny. In contrast, latency is characterized by the lack of significant lytic gene expression and the absence of infectious virus. Reactivation from latency is characterized by the re-entry of the virus into the lytic replication cycle and the production of recurrent disease. This unit describes the establishment of the mouse sensory neuron model of HSV-1 latency-reactivation as a useful in vivo system for the analysis of mechanisms involved in latency and reactivation. Assays including the determination of viral yields, immunohistochemical/immunofluorescent detection of viral antigens, and mRNA quantitation are used in experiments designed to investigate the network of cellular and viral proteins regulating HSV-1 lytic infection, latency, and reactivation. PMID:25367271

  8. Covalent functionalization of graphene with reactive intermediates.

    PubMed

    Park, Jaehyeung; Yan, Mingdi

    2013-01-15

    Graphene, a material made exclusively of sp(2) carbon atoms with its ? electrons delocalized over the entire 2D network, is somewhat chemically inert. Covalent functionalization can enhance graphene's properties including opening its band gap, tuning conductivity, and improving solubility and stability. Covalent functionalization of pristine graphene typically requires reactive species that can form covalent adducts with the sp(2) carbon structures in graphene. In this Account, we describe graphene functionalization reactions using reactive intermediates of radicals, nitrenes, carbenes, and arynes. These reactive species covalently modify graphene through free radical addition, CH insertion, or cycloaddition reactions. Free radical additions are among the most common reaction, and these radicals can be generated from diazonium salts and benzoyl peroxide. Electron transfer from graphene to aryl diazonium ion or photoactivation of benzoyl peroxide yields aryl radicals that subsequently add to graphene to form covalent adducts. Nitrenes, electron-deficient species generated by thermal or photochemical activation of organic azides, can functionalize graphene very efficiently. Because perfluorophenyl nitrenes show enhanced bimolecular reactions compared with alkyl or phenyl nitrenes, perfluorophenyl azides are especially effective. Carbenes are used less frequently than nitrenes, but they undergo CH insertion and C?C cycloaddition reactions with graphene. In addition, arynes can serve as a dienophile in a Diels-Alder type reaction with graphene. Further study is needed to understand and exploit the chemistry of graphene. The generation of highly reactive intermediates in these reactions leads to side products that complicate the product composition and analysis. Fundamental questions remain about the reactivity and regioselectivity of graphene. The differences in the basal plane and the undercoordinated edges of graphene and the zigzag versus arm-chair configurations warrant comprehensive studies. The availability of well-defined pristine graphene starting materials in large quantities remains a key obstacle to the advancement of synthetic graphene chemistry. PMID:23116448

  9. Measurement of the dependence of transverse energy production at large pseudorapidity on the hard-scattering kinematics of proton-proton collisions at $\\sqrt{s} = 2.76$ TeV with ATLAS

    E-print Network

    ATLAS Collaboration

    2015-12-01

    The relationship between jet production in the central region and the underlying-event activity in a pseudorapidity-separated region is studied in 4.0 pb$^{-1}$ of $\\sqrt{s} = 2.76$ TeV $pp$ collision data recorded with the ATLAS detector at the LHC. The underlying event is characterised through measurements of the average value of the sum of the transverse energy at large pseudorapidity downstream of one of the protons, which are reported here as a function of hard-scattering kinematic variables. The hard scattering is characterised by the average transverse momentum and pseudorapidity of the two highest transverse momentum jets in the event. The dijet kinematics are used to estimate, on an event-by-event basis, the scaled longitudinal momenta of the hard-scattered partons in the target and projectile beam-protons moving toward and away from the region measuring transverse energy, respectively. Transverse energy production at large pseudorapidity is observed to decrease with a linear dependence on the longitudinal momentum fraction in the target proton and to depend only weakly on that in the projectile proton. The results are compared to the predictions of various Monte Carlo event generators, which qualitatively reproduce the trends observed in data but generally underpredict the overall level of transverse energy at forward pseudorapidity.

  10. Measurement of the dependence of transverse energy production at large pseudorapidity on the hard-scattering kinematics of proton--proton collisions at $\\sqrt{s} = 2.76$ TeV with ATLAS

    E-print Network

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello

    2015-01-01

    The relationship between jet production in the central region and the underlying-event activity in a pseudorapidity-separated region is studied in $4.0$ pb$^{-1}$ of $\\sqrt{s} = 2.76$ TeV $pp$ collision data recorded with the ATLAS detector at the LHC. The underlying event is characterised through measurements of the average value of the sum of the transverse energy at large pseudorapidity downstream of one of the protons, which are reported here as a function of hard-scattering kinematic variables. The hard scattering is characterised by the average transverse momentum and pseudorapidity of the two highest transverse momentum jets in the event. The dijet kinematics are used to estimate, on an event-by-event basis, the scaled longitudinal momenta of the hard-scattered partons in the target and projectile beam-protons moving toward and away from the region measuring transverse energy, respectively. Transverse energy production at large pseudorapidity is observed to decrease with a linear dependence on the long...

  11. High missing OH reactivity in summertime boreal forest environment

    NASA Astrophysics Data System (ADS)

    Nölscher, A. C.; Williams, J.; Sinha, V.; Song, W.; Johnson, A.; Yassaa, N.; Phillips, G.; Crowley, J.; Axinte, R.; Fischer, H.; Gonzales, D.; Valverde-Canossa, J.; Vogel, A.; Hoffmann, T.; Rantala, P.; Rinne, J.; Kulmala, M.; Ouwersloot, H.; Vila, J.; Lelieveld, J.

    2012-04-01

    Forest emissions represent a strong potential sink for the main tropospheric oxidant, the hydroxyl radical (OH). Resulting photochemical products can influence ambient ozone, contribute to particle formation and growth processes, and therefore impact climate and air quality. Direct measurements of total OH reactivity in ambient air can reveal gaps in the general understanding of reactive gaseous emissions from the biosphere to the atmosphere. By comparing the contribution from individually measured compounds to the overall OH sink and the directly measured total OH reactivity, the size of any unaccounted for, or "missing" sink can be deduced. In July and August 2010 an intensive field measurement campaign (HUMPPA-COPEC 2010) was performed at the Finnish boreal forest station SMEAR II in Hyytiälä (Latitude 61° 51' N; Longitude 24° 17' E) to investigate the summertime emissions and photochemistry of volatile organic compounds (VOCs) [1]. Speciated VOCs, the key oxidants OH, O3 and NO3, as well as aerosol, ions and other trace gases were quantified. Total OH reactivity was measured directly using the Comparative Reactivity Method (CRM) [2]. This total OH reactivity method is an in-situ determination of the total loss rate of OH radicals caused by all reactive species in ambient air. During HUMPPA-COPEC 2010, total OH reactivity was monitored both inside and directly above the canopy. The impact of various parameters such as temperature and light dependent biogenic emissions and reaction products in "normal" and "stressed" conditions, the long-range transport of pollution and the boundary layer height development were characterized. For "normal" boreal conditions a missing reactivity of 58% was determined, whereas for "stressed" boreal conditions this increased to 89 %. Possible explanations are proposed to explain the high missing OH reactivity in summertime boreal forest environment. [1] J. Williams et al, 2011, Atmos. Chem. Phys., 11, 10599-10618 [2] V. Sinha et al, 2008, Atmos. Chem. Phys., 8, 2213-2227

  12. Total OH reactivity in a mediterranean forest of downy oaks

    NASA Astrophysics Data System (ADS)

    Zannoni, Nora; Gros, Valerie; Sarda, Roland; Lanza, Matteo; Bonsang, Bernard; Kalogridis, Cerise; Preunkert, Suzanne; Legrand, Michel; Jambert, Corinne; Boissard, Christophe; Lathiere, Juliette

    2015-04-01

    Forests emit large quantities of reactive molecules which can affect the concentration of the most important oxidizing agent in the atmosphere, the hydroxyl radical OH. There are still many unknowns on how biogenic compounds interact with the atmosphere. Among those, we still lack to fully understand the species that can potentially influence the atmospheric oxidative capacity and thus the OH cleansing effect over several forested areas. We conducted total OH reactivity measurements during spring 2014 inside and above the canopy height of a forest dominated at 80% by downy oaks in the Mediterranean basin (Observatoire Haute Provence site, France). Downy oak trees are capable to emit almost exclusively isoprene (~99%), the most abundant volatile organic compound and among the most reactive towards the OH radical. We measured the total OH reactivity with the Comparative Reactivity Method together with atmospheric concentrations of the primary compounds emitted by the forest, main secondary species generated from the oxidation of isoprene, and main atmospheric constituents. We then compared the OH reactivity inferred by measured compounds and their oxidation rate coefficients with the measured total OH reactivity. This approach permits to identify the presence of any primary emitted biogenic compound, unknown before and relevant for OH oxidation; or any secondary generated compound whose associated chemical mechanism is not well established. Our results show higher OH reactivity inside the canopy, with peaks up to 78 s-1, when isoprene concentration reached ~20 ppb due to temperature and PAR increase. Such high level of OH reactivity has only been observed in the tropics so far. Furthermore, our measured total OH reactivity closes the total amount of reactive species present in this specific forest, suggesting that we quantified precisely both the primary emitted species as well as the secondary generated products.

  13. Fuel temperature reactivity coefficient calculation by Monte Carlo perturbation techniques

    SciTech Connect

    Shim, H. J.; Kim, C. H.

    2013-07-01

    We present an efficient method to estimate the fuel temperature reactivity coefficient (FTC) by the Monte Carlo adjoint-weighted correlated sampling method. In this method, a fuel temperature change is regarded as variations of the microscopic cross sections and the temperature in the free gas model which is adopted to correct the asymptotic double differential scattering kernel. The effectiveness of the new method is examined through the continuous energy MC neutronics calculations for PWR pin cell problems. The isotope-wise and reaction-type-wise contributions to the FTCs are investigated for two free gas models - the constant scattering cross section model and the exact model. It is shown that the proposed method can efficiently predict the reactivity change due to the fuel temperature variation. (authors)

  14. Resveratrol alleviates the cytotoxicity induced by the radiocontrast agent, ioxitalamate, by reducing the production of reactive oxygen species in HK-2 human renal proximal tubule epithelial cells in vitro

    PubMed Central

    HUANG, YEN TA; CHEN, YI YA; LAI, YU HSIEN; CHENG, CHUAN CHU; LIN, TZU CHUN; SU, YING SHIH; LIU, CHIN HUNG; LAI, PEI CHUN

    2016-01-01

    Radiocontrast-induced nephropathy (RIN) is one of the leading causes of hospital-acquired acute kidney injury (AKI). The clinical strategies currently available for the prevention of RIN are insufficient. In this study, we aimed to determine whether resveratrol, a polyphenol phytoalexin, can be used to prevent RIN. For this purpose, in vitro experiments were performed using a human renal proximal tubule epithelial cell line (HK-2 cells). Following treatment for 48 h, the highly toxic radiocontrast agent, ioxitalamate, exerted cytotoxic effects on the HK-2 cells in a concentration-dependent manner, as shown by MTT assay. The half maximal inhibitory concentration (IC50) was found to be approximately 30 mg/ml. Flow cytometry also revealed a marked increase in the number of apoptotic cells following exposure to ioxitalamate. In addition, the number of necrotic, but not necroptotic cells was increased. However, treatment with resveratrol (12.5 ?M) for 48 h significantly alleviated ioxitalamate (30 mg/ml)-induced cytotoxicity, by reducing cytosolic DNA fragmentation, increasing the expression of the anti-apoptotic protein, Bcl-2 (B-cell lymphoma 2), and survivin, activating caspase-3, preventing autophagic death and suppressing the production of reactive oxygen species (ROS). Resveratrol also suppressed the ioxitalamate-induced formation of 8-hydroxy-2?-deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage. N-acetylcysteine (NAC), a ROS scavenger commonly used to prevent RIN, also reduced ioxitalamate-induced cytotoxicity, but at a high concentration of 1 mM. Sirtuin (SIRT)1 and SIRT3 were not found to play a role in these effects. Overall, our findings suggest that resveratrol may prove to be an effective adjuvant therapy for the prevention of RIN. PMID:26573558

  15. Resveratrol alleviates the cytotoxicity induced by the radiocontrast agent, ioxitalamate, by reducing the production of reactive oxygen species in HK-2 human renal proximal tubule epithelial cells in vitro.

    PubMed

    Huang, Yen Ta; Chen, Yi Ya; Lai, Yu Hsien; Cheng, Chuan Chu; Lin, Tzu Chun; Su, Ying Shih; Liu, Chin Hung; Lai, Pei Chun

    2016-01-01

    Radiocontrast-induced nephropathy (RIN) is one of the leading causes of hospital-acquired acute kidney injury (AKI). The clinical strategies currently available for the prevention of RIN are insufficient. In this study, we aimed to determine whether resveratrol, a polyphenol phytoalexin, can be used to prevent RIN. For this purpose, in vitro experiments were performed using a human renal proximal tubule epithelial cell line (HK-2 cells). Following treatment for 48 h, the highly toxic radiocontrast agent, ioxitalamate, exerted cytotoxic effects on the HK-2 cells in a concentration-dependent manner, as shown by MTT assay. The half maximal inhibitory concentration (IC50) was found to be approximately 30 mg/ml. Flow cytometry also revealed a marked increase in the number of apoptotic cells following exposure to ioxitalamate. In addition, the number of necrotic, but not necroptotic cells was increased. However, treatment with resveratrol (12.5 µM) for 48 h significantly alleviated ioxitalamate (30 mg/ml)-induced cytotoxicity, by reducing cytosolic DNA fragmentation, increasing the expression of the anti-apoptotic protein, Bcl-2 (B-cell lymphoma 2), and survivin, activating caspase-3, preventing autophagic death and suppressing the production of reactive oxygen species (ROS). Resveratrol also suppressed the ioxitalamate-induced formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage. N-acetylcysteine (NAC), a ROS scavenger commonly used to prevent RIN, also reduced ioxitalamate-induced cytotoxicity, but at a high concentration of 1 mM. Sirtuin (SIRT)1 and SIRT3 were not found to play a role in these effects. Overall, our findings suggest that resveratrol may prove to be an effective adjuvant therapy for the prevention of RIN. PMID:26573558

  16. Rapid memory reactivation revealed by oscillatory entrainment.

    PubMed

    Wimber, Maria; Maaß, Anne; Staudigl, Tobias; Richardson-Klavehn, Alan; Hanslmayr, Simon

    2012-08-21

    Episodic memory refers to humans' unique ability to mentally reconstruct past events. Neurocomputational models predict that remembering entails the reinstatement of brain activity that was present when an event was initially experienced [1-5], a claim that has recently gained support from functional imaging work in humans [6-14]. The nature of this reactivation, however, is still unclear. Cognitive models claim that retrieval is set off by an early reactivation of stored memory representations ("ecphory") [15-17]. However, reinstatement as found in imaging studies might also reflect postretrieval processes that operate on the products of retrieval and are thus a consequence rather than a precondition of remembering. Here, we used frequency entrainment as a novel method of tagging memories in the human electroencephalogram (EEG). Participants studied words presented on flickering backgrounds, entraining a steady-state brain response at either 6 or 10 Hz. We found that these frequency signatures rapidly reemerged during a later memory test when participants successfully recognized a word. An additional behavioral experiment suggested that this reactivation occurs in the absence of conscious memory for the frequencies entrained during study. The findings provide empirical evidence for the role of rapid, likely unconscious memory reactivation during retrieval. PMID:22795695

  17. Molecular-beam scattering

    SciTech Connect

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N/sub 2/ from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl ..-->.. NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2/sup 2/P/sub 3/2/) and Na(3/sup 2/P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included.

  18. A transport based one-dimensional perturbation code for reactivity calculations in metal systems

    SciTech Connect

    Wenz, T.R.

    1995-02-01

    A one-dimensional reactivity calculation code is developed using first order perturbation theory. The reactivity equation is based on the multi-group transport equation using the discrete ordinates method for angular dependence. In addition to the first order perturbation approximations, the reactivity code uses only the isotropic scattering data, but cross section libraries with higher order scattering data can still be used with this code. The reactivity code obtains all the flux, cross section, and geometry data from the standard interface files created by ONEDANT, a discrete ordinates transport code. Comparisons between calculated and experimental reactivities were done with the central reactivity worth data for Lady Godiva, a bare uranium metal assembly. Good agreement is found for isotopes that do not violate the assumptions in the first order approximation. In general for cases where there are large discrepancies, the discretized cross section data is not accurately representing certain resonance regions that coincide with dominant flux groups in the Godiva assembly. Comparing reactivities calculated with first order perturbation theory and a straight {Delta}k/k calculation shows agreement within 10% indicating the perturbation of the calculated fluxes is small enough for first order perturbation theory to be applicable in the modeled system. Computation time comparisons between reactivities calculated with first order perturbation theory and straight {Delta}k/k calculations indicate considerable time can be saved performing a calculation with a perturbation code particularly as the complexity of the modeled problems increase.

  19. Reactive Melt Infiltration Of Silicon Into Porous Carbon

    NASA Technical Reports Server (NTRS)

    Behrendt, Donald R.; Singh, Mrityunjay

    1994-01-01

    Report describes study of synthesis of silicon carbide and related ceramics by reactive melt infiltration of silicon and silicon/molybdenum alloys into porous carbon preforms. Reactive melt infiltration has potential for making components in nearly net shape, performed in less time and at lower temperature. Object of study to determine effect of initial pore volume fraction, pore size, and infiltration material on quality of resultant product.

  20. Rapid and transient stimulation of intracellular reactive oxygen species by melatonin in normal and tumor leukocytes

    SciTech Connect

    Radogna, Flavia; Paternoster, Laura; De Nicola, Milena; Cerella, Claudia; Ammendola, Sergio; Bedini, Annalida; Tarzia, Giorgio; Aquilano, Katia; Ciriolo, Maria; Ghibelli, Lina

    2009-08-15

    Melatonin is a modified tryptophan with potent biological activity, exerted by stimulation of specific plasma membrane (MT1/MT2) receptors, by lower affinity intracellular enzymatic targets (quinone reductase, calmodulin), or through its strong anti-oxidant ability. Scattered studies also report a perplexing pro-oxidant activity, showing that melatonin is able to stimulate production of intracellular reactive oxygen species (ROS). Here we show that on U937 human monocytes melatonin promotes intracellular ROS in a fast (< 1 min) and transient (up to 5-6 h) way. Melatonin equally elicits its pro-radical effect on a set of normal or tumor leukocytes; intriguingly, ROS production does not lead to oxidative stress, as shown by absence of protein carbonylation, maintenance of free thiols, preservation of viability and regular proliferation rate. ROS production is independent from MT1/MT2 receptor interaction, since a) requires micromolar (as opposed to nanomolar) doses of melatonin; b) is not contrasted by the specific MT1/MT2 antagonist luzindole; c) is not mimicked by a set of MT1/MT2 high affinity melatonin analogues. Instead, chlorpromazine, the calmodulin inhibitor shown to prevent melatonin-calmodulin interaction, also prevents melatonin pro-radical effect, suggesting that the low affinity binding to calmodulin (in the micromolar range) may promote ROS production.

  1. Nucleophilic substitution with two reactive centers: The CN- + CH3I case

    NASA Astrophysics Data System (ADS)

    Carrascosa, E.; Bawart, M.; Stei, M.; Linden, F.; Carelli, F.; Meyer, J.; Geppert, W. D.; Gianturco, F. A.; Wester, R.

    2015-11-01

    The nucleophilic substitution reaction CN- + CH3I allows for two possible reactive approaches of the reactant ion onto the methyl halide, which lead to two different product isomers. Stationary point calculations predict a similar shape of the potential and a dominant collinear approach for both attacks. In addition, an H-bonded pre-reaction complex is identified as a possible intermediate structure. Submerged potential energy barriers hint at a statistical formation process of both CNCH3 and NCCH3 isomers at the experimental collision energies. Experimental angle- and energy differential cross sections show dominant direct rebound dynamics and high internal excitation of the neutral product. No distinct bimodal distributions can be extracted from the velocity images, which impedes the indication of a specific preference towards any of the product isomers. A forward scattering simulation based on the experimental parameters describes accurately the experimental outcome and shows how the possibility to discriminate between the two isomers is mainly hindered by the large product internal excitation.

  2. Recent changes in anthropogenic reactive nitrogen compounds

    NASA Astrophysics Data System (ADS)

    Andronache, Constantin

    2014-05-01

    Significant anthropogenic perturbations of the nitrogen cycle are the result of rapid population growth, with mounting need for food and energy production. The increase of reactive nitrogen compounds (such as NOx, HNO3, NH3, and N2O) has a significant impact on human health, environment, and climate. NOx emissions contribute to O3 chemistry, aerosol formation and acidic precipitation. Ammonia is a notable atmospheric pollutant that may deteriorate ecosystems and contribute to respiratory problems. It reacts with acidic gases to form aerosols or is deposited back to ecosystems. The application of fertilizers accounts for most of the N2O production, adding to greenhouse gas emissions. We analyze the change of some reactive nitrogen compounds based on observations, in eastern United States. Results show that the control of NOx and SO2 emissions over the last decades caused a significant decrease of acidic deposition. The nitrate deposition is highest in eastern US, while the ammonium ion concentration is highest in central US regions. Overall, the inorganic nitrogen wet deposition from nitrate and ammonium is enhanced in central, and eastern US. Research shows that sensitive ecosystems in northeastern regions exhibit a slow recovery from the accumulated effects of acidic deposition. Given the growing demand for nitrogen in agriculture and industry, we discuss possible pathways to reduce the impact of excess reactive nitrogen on the environment.

  3. Threshold resonance effects in reactive processes

    NASA Astrophysics Data System (ADS)

    Simbotin, I.; Ghosal, S.; Côté, R.

    2014-04-01

    We investigate the effect of near threshold resonances in reactive scattering at low energy. We find a general type of anomalous behavior of the cross sections, and illustrate it with a real system (H2+Cl). For inelastic processes, the anomalous energy dependence of the total cross section is given by ? ˜k-3 (with k ??? ). The standard threshold behavior given by Wigner's law (? ˜k-1) is eventually recovered at vanishing energies, but its validity is now limited to a much narrower range of energies. The anomalous behavior leads to reaction rate coefficients behaving as K ˜1/T instead of the expected constant rate of the Wigner regime. We also provide analytical expressions for s-wave cross sections, and discuss the implication in ultracold physics and chemistry.

  4. Bacterial responses to reactive chlorine species.

    PubMed

    Gray, Michael J; Wholey, Wei-Yun; Jakob, Ursula

    2013-01-01

    Hypochlorous acid (HOCl), the active ingredient of household bleach, is the most common disinfectant in medical, industrial, and domestic use and plays an important role in microbial killing in the innate immune system. Given the critical importance of the antimicrobial properties of chlorine to public health, it is surprising how little is known about the ways in which bacteria sense and respond to reactive chlorine species (RCS). Although the literature on bacterial responses to reactive oxygen species (ROS) is enormous, work addressing bacterial responses to RCS has begun only recently. Transcriptomic and proteomic studies now provide new insights into how bacteria mount defenses against this important class of antimicrobial compounds. In this review, we summarize the current knowledge, emphasizing the overlaps between RCS stress responses and other more well-characterized bacterial defense systems, and identify outstanding questions that represent productive avenues for future research. PMID:23768204

  5. Resilience and reactivity of global food security

    PubMed Central

    Suweis, Samir; Carr, Joel A.; Maritan, Amos; Rinaldo, Andrea; D’Odorico, Paolo

    2015-01-01

    The escalating food demand by a growing and increasingly affluent global population is placing unprecedented pressure on the limited land and water resources of the planet, underpinning concerns over global food security and its sensitivity to shocks arising from environmental fluctuations, trade policies, and market volatility. Here, we use country-specific demographic records along with food production and trade data for the past 25 y to evaluate the stability and reactivity of the relationship between population dynamics and food availability. We develop a framework for the assessment of the resilience and the reactivity of the coupled population–food system and suggest that over the past two decades both its sensitivity to external perturbations and susceptibility to instability have increased. PMID:25964361

  6. Resilience and reactivity of global food security.

    PubMed

    Suweis, Samir; Carr, Joel A; Maritan, Amos; Rinaldo, Andrea; D'Odorico, Paolo

    2015-06-01

    The escalating food demand by a growing and increasingly affluent global population is placing unprecedented pressure on the limited land and water resources of the planet, underpinning concerns over global food security and its sensitivity to shocks arising from environmental fluctuations, trade policies, and market volatility. Here, we use country-specific demographic records along with food production and trade data for the past 25 y to evaluate the stability and reactivity of the relationship between population dynamics and food availability. We develop a framework for the assessment of the resilience and the reactivity of the coupled population-food system and suggest that over the past two decades both its sensitivity to external perturbations and susceptibility to instability have increased. PMID:25964361

  7. Self-masking controlled by metallic seed layer during glass dry-etching for optically scattering surfaces

    SciTech Connect

    Hein, E.; Fox, D.; Fouckhardt, H.

    2010-02-15

    During reactive ion etching in a high density Ar/CF{sub 4} plasma, nonvolatile halogen compounds are generated on the glass surface and act as statistically distributed micromasks. As a consequence surface roughness occurs, which can be used as additional surface functionality in certain classes of applications, where defined optical scattering is desired. The glass etch process described in this contribution enables user-defined scattering characteristics. The deposition of a thin metallic layer of Cu on top of the samples before dry-etching provides an additional seed for the production of micromasks, resulting in higher reproducibility. By varying the etch parameters a multitude of different surface morphologies can be realized both on borosilicate glasses and on fused silica.

  8. Emotional Reactivity and Psychological Distress.

    ERIC Educational Resources Information Center

    Bartle-Haring, Suzanne; Rosen, Karen H.; Stith, Sandra M.

    2002-01-01

    This article reports on an empirical test of Bowen's hypothesized relationships between differentiation of self and psychological symptoms, and examines further evidence for the construct validity of a newly developed instrument, the Behavioral and Emotional Reactivity Index (BERI). Finds an indirect relationship between emotional reactivity

  9. Imaging with Scattered Neutrons

    E-print Network

    H. Ballhausen; H. Abele; R. Gaehler; M. Trapp; A. Van Overberghe

    2006-10-30

    We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.

  10. Rayleigh scattering. [molecular scattering terminology redefined

    NASA Technical Reports Server (NTRS)

    Young, A. T.

    1981-01-01

    The physical phenomena of molecular scattering are examined with the objective of redefining the confusing terminology currently used. The following definitions are proposed: molecular scattering consists of Rayleigh and vibrational Raman scattering; the Rayleigh scattering consists of rotational Raman lines and the central Cabannes line; the Cabannes line is composed of the Brillouin doublet and the central Gross or Landau-Placzek line. The term 'Rayleigh line' should never be used.

  11. COAL SLAGGING AND REACTIVITY TESTING

    SciTech Connect

    Donald P. McCollor; Kurt E. Eylands; Jason D. Laumb

    2003-10-01

    Union Fenosa's La Robla I Power Station is a 270-MW Foster Wheeler arch-fired system. The unit is located at the mine that provides a portion of the semianthracitic coal. The remaining coals used are from South Africa, Russia, Australia, and China. The challenges at the La Robla I Station stem from the various fuels used, the characteristics of which differ from the design coal. The University of North Dakota Energy & Environmental Research Center (EERC) and the Lehigh University Energy Research Center (LUERC) undertook a program to assess problematic slagging and unburned carbon issues occurring at the plant. Full-scale combustion tests were performed under baseline conditions, with elevated oxygen level and with redistribution of air during a site visit at the plant. During these tests, operating information, observations and temperature measurements, and coal, slag deposit, and fly ash samples were obtained to assess slagging and unburned carbon. The slagging in almost all cases appeared due to elevated temperatures rather than fuel chemistry. The most severe slagging occurred when the temperature at the sampling port was in excess of 1500 C, with problematic slagging where first-observed temperatures exceeded 1350 C. The presence of anorthite crystals in the bulk of the deposits analyzed indicates that the temperatures were in excess of 1350 C, consistent with temperature measurements during the sampling period. Elevated temperatures and ''hot spots'' are probably the result of poor mill performance, and a poor distribution of the coal from the mills to the specific burners causes elevated temperatures in the regions where the slag samples were extracted. A contributing cause appeared to be poor combustion air mixing and heating, resulting in oxygen stratification and increased temperatures in certain areas. Air preheater plugging was observed and reduces the temperature of the air in the windbox, which leads to poor combustion conditions, resulting in unburned carbon as well as slagging. A second phase of the project involved advanced analysis of the baseline coal along with an Australian coal fired at the plant. These analysis results were used in equilibrium thermodynamic modeling along with a coal quality model developed by the EERC to assess slagging, fouling, and opacity for the coals. Bench-scale carbon conversion testing was performed in a drop-tube furnace to assess the reactivity of the coals. The Australian coal had a higher mineral content with significantly more clay minerals present than the baseline coal. The presence of these clay minerals, which tend to melt at relatively low temperatures, indicated a higher potential for problematic slagging than the baseline coal. However, the pyritic minerals, comprising over 25% of the baseline mineral content, may form sticky iron sulfides, leading to severe slagging in the burner region if local areas with reducing conditions exist. Modeling results indicated that neither would present significant fouling problems. The Australian coal was expected to show slagging behavior much more severe than the baseline coal except at very high furnace temperatures. However, the baseline coal was predicted to exhibit opacity problems, as well as have a higher potential for problematic calcium sulfate-based low-temperature fouling. The baseline coal had a somewhat higher reactivity than the Australian coal, which was consistent with both the lower average activation energy for the baseline coal and the greater carbon conversion at a given temperature and residence time. The activation energy of the baseline coal showed some effect of oxygen on the activation energy, with E{sub a} increasing at the lower oxygen concentration, but may be due to the scatter in the baseline coal kinetic values at the higher oxygen level tested.

  12. Total OH reactivity measurements in laboratory studies of the photooxidation of isoprene

    NASA Astrophysics Data System (ADS)

    Nakashima, Yoshihiro; Tsurumaru, Hiroshi; Imamura, Takashi; Bejan, Iustinian; Wenger, John C.; Kajii, Yoshizumi

    2012-12-01

    The hydroxyl radical (OH) is the principal oxidizing agent in Earth's troposphere. Measurements of the total OH reactivity, defined as the reciprocal of the lifetime of OH, have been employed in field studies to estimate the entire amount of reactive trace gases in the atmosphere. Here, the OH reactivity technique has been employed in laboratory studies of the OH initiated atmospheric oxidation of the important biogenic volatile organic compound, isoprene. A significant discrepancy was observed between measured and calculated OH reactivity, indicating that OH was reacting with some oxidation products not measured in the experiment. The "missing" OH reactivity gradually increased as the oxidation progressed and contributed up to 40% of the total OH reactivity. In the presence of NO, the "missing" OH reactivity is likely due to a number of first-generation products produced in low yields, while in the absence of NO, alternative pathways that produce less reactive products are also occurring.This work demonstrates that OH reactivity measurements can be successfully incorporated into atmospheric simulation chamber studies of VOC degradation. The OH reactivity technique has the potential to be a powerful tool for elucidating finer details of VOC oxidation.

  13. Tousled-like Kinases Modulate Reactivation of Gammaherpesviruses from Latency

    PubMed Central

    Dillon, Patrick J.; Gregory, Sean M.; Tamburro, Kristen; Peck, Marcia K.; Johnson, Gary L.; Raab-Traub, Nancy; Dittmer, Dirk P.; Damania, Blossom

    2013-01-01

    Summary Kaposi’s sarcoma-associated herpesvirus (KSHV) is linked to human malignancies. The majority of tumor cells harbor latent virus and a small percentage undergo spontaneous lytic replication. Both latency and lytic replication are important for viral pathogenesis and spread but the cellular players involved in the switch between the two viral lifecycle phases are not clearly understood. We conducted a siRNA screen targeting the cellular kinome and identified Tousled-like kinases (TLKs) as cellular kinases that control KSHV reactivation from latency. Upon treatment of latent KSHV-infected cells with siRNAs targeting TLKs, we saw robust viral reactivation. Knockdown of TLKs in latent KSHV-infected cells induced expression of viral lytic proteins and production of infectious virus. TLKs were also found to play a role in regulating reactivation from latency of another related oncogenic gammaherpesvirus, Epstein-Barr virus (EBV). Our results establish the TLKs as cellular repressors of gammaherpesviral reactivation. PMID:23414760

  14. Grinding methods to enhance the reactivity of olivine

    SciTech Connect

    Summers, Cathy A.; Dahlin, David C.; Rush, Gilbert E.; O'Connor, William K.; Gerdemann, Stephen J.

    2005-08-01

    The Albany Research Center (ARC) conducted studies of mechanical activation by conventional and ultrafine grinding techniques to enhance olivine reactivity in mineral carbonation reactions. Activated olivine is one of several solid feed materials used at ARC in reactions with carbon dioxide to form carbonate minerals. This paper compares grinding techniques via energy demand data and product characteristics, including particle size distributions, surface areas, full-width-at-half-maximum (FWHM) XRD analyses, and particle morphology by SEM analyses. Reactivity was calculated by percent conversion to carbonate in subsequent carbonation tests. Particle size reduction has the greatest impact on reactivity, and wet grinding is more energy efficient than dry grinding. Large additional inputs of energy to increase surface area or reduce crystallinity do not result in proportional improvements in reactivity.

  15. Reactivities of Precision Cleaning Solvents with Hypergolic Propellants

    NASA Technical Reports Server (NTRS)

    Davis, Dennis D.; Delgado, Rafael H.; Williams, James H.

    1999-01-01

    The reactivities of several selected halogenated precision cleaning solvents with hypergolic propellants has been determined by analysis of the rates of formation of halide ion decomposition products. The solvents were Asahiklin AK 225, Asahiklin AK 225 AES, HFE 7100, HFE 7100 DE, Vertrel XF, Vertrel MCA, Vertrel MCA Plus, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), and trans-1,2-dichloroethylene (DCE). The propellants were hydrazine (HZ), monomethylhydrazine (MMH), and mixed oxides of nitrogen (MON-3). The Vertrel solvents showed significant reactivity with HZ. All of the solvents except DCE exhibited significant reactivity with MMH, particularly HFE 7100 DE and CFC-113. HFE 7100 DE, Vertrel MCA, and Vertrel MCA Plus also showed significant reactivity with MON-3 oxidizer.

  16. The Penrose photoproduction scenario for NGC 4151: A black hole gamma-ray emission mechanism for active galactic nuclei and Seyfert galaxies. [Compton scattering and pair production

    NASA Technical Reports Server (NTRS)

    Leiter, D.

    1979-01-01

    A consistent theoretical interpretation is given for the suggestion that a steepening of the spectrum between X-ray and gamma ray energies may be a general, gamma-ray characteristic of Seyfert galaxies, if the diffuse gamma ray spectrum is considered to be a superposition of unresolved contributions, from one or more classes of extragalactic objects. In the case of NGC 4151, the dominant process is shown to be Penrose Compton scattering in the ergosphere of a Kerr black hole, assumed to exist in the Seyfert's active galactic nucleus.

  17. Hydrothermal reactivity of saponite.

    USGS Publications Warehouse

    Whitney, G.

    1983-01-01

    The nature and extent of the reactions of synthetic Fe-free saponite have been investigated under experimental hydrothermal conditions as a first step towards understanding saponite reactivity under relatively simple conditions. Saponite crystallizes from amorphous gel of ideal saponite composition within 7 days at 300o-550oC under P = 1 kbar. Reactions subsequent to this initial crystallization depend on reaction T and interlayer cations. Saponite is found to react hydrothermally, over a period of 200 days, at T down to 400oC, at least 150oC lower than previously reported, but showed no signs of reaction below 400oC. At 450oC, a mixture of talc/saponite and saponite/phlogopite clays forms from K-saponite via intracrystalline layer transformations, while above 450oC the initial K-saponite dissolves, with talc and phlogopite forming as discrete phases. After 200 days reactions at 400-450oC were not complete, so that given sufficient time to reach equilibrium, a lower hydrothermal stability limit for saponite is possible. Further study of the Fe-bearing saponite system will be required before experimental results can be applied to natural systems.-D.F.B.

  18. Cylindrical converging shock initiation of reactive materials

    NASA Astrophysics Data System (ADS)

    Jenkins, Charles M.; Horie, Yasuyuki; Lindsay, Christopher Michael; Butler, George C.; Lambert, David; Welle, Eric

    2012-03-01

    Recent research has been conducted that builds on the Forbes et al. (1997) study of inducing a rapid solid state reaction in a highly porous core using a converging cylindrical shock driven by a high explosive. The high explosive annular charge used in this research to compress the center reactive core was comparable to PBXN-110. Some modifications were made on the physical configuration of the test item for scale-up and ease of production. The reactive materials (I2O5/Al and I2O5/Al/Teflon) were hand mixed and packed to a tap density of about 32 percent. Data provided by a Cordon 114 high speed framing camera and a Photon Doppler Velocimetry instrument provided exit gas expansion, core particle and cylinder wall velocities. Analysis indicates that the case expansion velocity differs according to the core formulation and behaved similar to the baseline high explosive core with the exit gas of the reactive materials producing comparable velocities. Results from CTH hydrocode used to model the test item compares favorably to the experimental results.

  19. Understanding the Reactivity of Lunar Dust for Future Lunar Missions

    NASA Technical Reports Server (NTRS)

    Wallace, William; Taylor, L. A.; Jeevarajan, Antony

    2009-01-01

    During the Apollo missions, dust was found to cause numerous problems for various instruments and systems. Additionally, the dust may have caused momentary health issues for some of the astronauts. Therefore, the plan to resume robotic and manned missions to the Moon in the next decade has led to a renewed interest in the properties of lunar dust, ranging from geological to chemical to toxicological. An important property to understand is the reactivity of the dust particles. Due to the lack of an atmosphere on the Moon, there is nothing to protect the lunar soil from ultraviolet radiation, solar wind, and meteorite impacts. These processes could all serve to activate the soil, or produce reactive surface species. On the Moon, these species can be maintained for millennia without oxygen or water vapor present to satisfy the broken bonds. Unfortunately, the Apollo dust samples that were returned to Earth were inadvertently exposed to the atmosphere, causing them to lose their reactive characteristics. In order to aid in the preparation of mitigation techniques prior to returning to the Moon, we measured the ability of lunar dust, lunar dust simulant, and quartz samples to produce hydroxyl radicals in solution[1]. As a first approximation of meteorite impacts on the lunar surface, we ground samples using a mortar and pestle. Our initial studies showed that all three test materials (lunar dust (62241), lunar dust simulant (JSC-1Avf), and quartz) produced hydroxyl radicals after grinding and mixing with water. However, the radical production of the ground lunar dust was approximately 10-fold and 3-fold greater than quartz and JSC-1 Avf, respectively. These reactivity differences between the different samples did not correlate with differences in specific surface area. The increased reactivity produced for the quartz by grinding was attributed to the presence of silicon- or oxygen-based radicals on the surface, as had been seen previously[2]. These radicals may also play a part in the reactivity of the lunar dust and lunar simulant. However, other factors would seem to be required to account for the greatly increased reactivity of the lunar soil. It was proposed that nanometer-size Fe 0 (zero valent) particles in the lunar soil might play a role, as they are not present in quartz or lunar dust simulant. The present work has been performed with the aim of understanding the origin of the considerable reactivity of lunar dust[3]. We have ground 8 lunar soils of varying maturity and source (highland or mare) and measured the hydroxyl-radical production and decay of the reactivity. It was determined that there is a direct correlation between the reactivity and the amount of nanophase metallic iron particles (as a function of soil maturity, I s/FeO, in which Is is the amount of iron present as nanophase iron particles present and FeO is the total iron content) in the samples; thus, the highland soils, with their lesser total FeO content, are less reactive than ground mare soils. Additionally, grinding of nanophase iron simulant [4] showed reactivity in line with the lunar soils and much greater than lunar dust simulant or quartz. Studies aimed at determining the time required to deactivate the reactive soils in a habitable environment showed that the average time to reach 50% of the initial reactivity was approximately 3.5 hours. However, even after one week, none of the soils had returned completely to its unground level of reactivity. In contrast to the reactivity results, there was no obvious correlation between the maturity of the soil and its deactivation time. These results provide the first chemical reactivity and persistence values as an important property of lunar soils, data that is paramount as mankind prepares to return to the Moon.

  20. Screening of cellulases for biofuel production: online monitoring of the enzymatic hydrolysis of insoluble cellulose using high-throughput scattered light detection.

    PubMed

    Jäger, Gernot; Wulfhorst, Helene; Zeithammel, Erik U; Elinidou, Efthimia; Spiess, Antje C; Büchs, Jochen

    2011-01-01

    A new prospective cellulase assay simultaneously combining high-throughput, online analysis and insoluble cellulosic substrates is described. The hydrolysis of three different insoluble cellulosic substrates, catalysed by a commercial cellulase preparation from Trichoderma reesei (Celluclast), was monitored using the BioLector - allowing online monitoring of scattered light intensities in a continuously shaken microtiter plate. Cellulase activities could be quantitatively assayed using the BioLector. At low cellulase/cellulose ratios, the Michaelis-Menten parameters of the cellulase mixture were mainly affected by the crystallinity index of the cellulose. Here, the apparent maximum cellulase activities inversely correlated with the crystallinity index of the cellulose. At high cellulase/cellulose ratios the particle size of the cellulose, defining the external surface area accessible to the cellulases, was the key determining factor for cellulase activity. The developed technique was also successfully applied to evaluate the pH optimum of cellulases. Moreover, the non-hydrolytic deagglomeration of cellulose particles was investigated, for the first time, using high-throughput scattered light detection. In conclusion, this cellulase assay ideally links high-throughput, online analysis and realistic insoluble cellulosic substrates in one simple system. It will considerably simplify and accelerate fundamental research on cellulase screening. PMID:21184439

  1. Conservation of reactive electromagnetic energy in reactive time

    E-print Network

    Gerald Kaiser

    2015-01-05

    The complex Poynting theorem (CPT) is extended to a canonical time-scale domain $(t,s)$. Time-harmonic phasors are replaced by the positive-frequency parts of general fields, which extend analytically to complex time $t+is$, with $s>0$ interpreted as a time resolution scale. The real part of the extended CPT gives conservation in $t$ of a time-averaged field energy, and its imaginary part gives conservation in $s$ of a time-averaged reactive energy. In both cases, the averaging windows are determined by a Cauchy kernel of width $\\Delta t\\sim \\pm s$. This completes the time-harmonic CPT, whose imaginary part is generally supposed to be vaguely `related to' reactive energy without giving a conservation law, or even an expression, for the latter. The interpretation of $s$ as reactive time, tracking the leads and lags associated with stored capacitative and inductive energy, gives a simple explanation of the volt-ampere reactive (var) unit measuring reactive power: a var is simply one Joule per reactive second. The related 'complex radiation impedance density' is introduced to represent the field's local reluctance to radiate.

  2. Conservation of reactive electromagnetic energy in reactive time

    E-print Network

    Kaiser, Gerald

    2015-01-01

    The complex Poynting theorem (CPT) is extended to a canonical time-scale domain $(t,s)$. Time-harmonic phasors are replaced by the positive-frequency parts of general fields, which extend analytically to complex time $t+is$, with $s>0$ interpreted as a time resolution scale. The real part of the extended CPT gives conservation in $t$ of a time-averaged field energy, and its imaginary part gives conservation in $s$ of a time-averaged reactive energy. In both cases, the averaging windows are determined by a Cauchy kernel of width $\\Delta t\\sim \\pm s$. This completes the time-harmonic CPT, whose imaginary part is generally supposed to be vaguely `related to' reactive energy without giving a conservation law, or even an expression, for the latter. The interpretation of $s$ as reactive time, tracking the leads and lags associated with stored capacitative and inductive energy, gives a simple explanation of the volt-ampere reactive (var) unit measuring reactive power: a var is simply one Joule per reactive second. T...

  3. Reactive Intermediates in Cytochrome P450 Catalysis*

    PubMed Central

    Krest, Courtney M.; Onderko, Elizabeth L.; Yosca, Timothy H.; Calixto, Julio C.; Karp, Richard F.; Livada, Jovan; Rittle, Jonathan; Green, Michael T.

    2013-01-01

    Recently, we reported the spectroscopic and kinetic characterizations of cytochrome P450 compound I in CYP119A1, effectively closing the catalytic cycle of cytochrome P450-mediated hydroxylations. In this minireview, we focus on the developments that made this breakthrough possible. We examine the importance of enzyme purification in the quest for reactive intermediates and report the preparation of compound I in a second P450 (P450ST). In an effort to bring clarity to the field, we also examine the validity of controversial reports claiming the production of P450 compound I through the use of peroxynitrite and laser flash photolysis. PMID:23632017

  4. Preparation of reactive beta-dicalcium silicate

    DOEpatents

    Shen, M.S.; Chen, J.M.; Yang, R.T.

    1980-02-28

    This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica, and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane, and hydrogen, at a temperature of about 850 to 1000/sup 0/C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

  5. Preparation of reactive beta-dicalcium silicate

    DOEpatents

    Shen, Ming-Shing (Laramie, WY, NJ); Chen, James M. (Rahway, NJ); Yang, Ralph T. (Amherst, NY)

    1982-01-01

    This invention relates to the preparation of fine particles of reactive beta-dicalcium silicate by means of a solid state process which comprises firing a mixture of calcium sulfate, silica and a reducing additive selected from the group consisting of calcium sulfide, carbon, carbon monoxide, methane and hydrogen, at a temperature of about 850.degree.-1000.degree. C. A carrier gas such as nitrogen or carbon dioxide may also be added, if desired. A high concentration of sulfur dioxide is a by-product of this process.

  6. Chemorheology of reactive systems: Finite element analysis

    NASA Technical Reports Server (NTRS)

    Douglas, C.; Roylance, D.

    1982-01-01

    The equations which govern the nonisothermal flow of reactive fluids are outlined, and the means by which finite element analysis is used to solve these equations for the sort of arbitrary boundary conditions encountered in industrial practice are described. The performance of the computer code is illustrated by several trial problems, selected more for their value in providing insight to polymer processing flows than as practical production problems. Although a good deal remains to be learned as to the performance and proper use of this numerical technique, it is undeniably useful in providing better understanding of today's complicated polymer processing problems.

  7. Study of Marine Natural Products Including Resorcyclic Acid Lactones from Humicola fuscoatra That Reactivate Latent HIV-1 Expression in an in Vitro Model of Central Memory CD4+ T Cells

    PubMed Central

    2015-01-01

    An extract of Humicola fuscoatra (UCSC strain no. 108111A) was shown to reactivate latent HIV-1 expression in an in vitro model of central memory CD4+ T cells. We report the bioassay-guided isolation and structure determination of several resorcyclic acid lactones, including four known compounds, radicicol (1, aka. monorden) and pochonins B (2), C (3), and N (4), and three new analogues, radicicols B–D (5–7). Compounds 1–3 and 5 showed moderate activities in the memory T cell model of HIV-1 latency. Radicicol (1) displayed lower potency in reactivating latent HIV-1 (EC50 = 9.1 ?M) relative to the HDAC inhibitors apicidin (EC50 = 0.3 ?M), romidepsin (EC50 = 0.003 ?M), and SAHA (EC50 = 0.6 ?M); however, it achieved equivalent maximum efficacy relative to the positive control compounds (98% of SAHA and romidepsin). PMID:24495105

  8. [Hyper-reactive malarial splenomegaly].

    PubMed

    Maazoun, F; Deschamps, O; Barros-Kogel, E; Ngwem, E; Fauchet, N; Buffet, P; Froissart, A

    2015-11-01

    Hyper-reactive malarial splenomegaly is a rare and severe form of chronic malaria. This condition is a common cause of splenomegaly in endemic areas. The pathophysiology of hyper-reactive malarial splenomegaly involves an intense immune reaction (predominantly B cell-driven) to repeated/chronic infections with Plasmodium sp. The diagnosis may be difficult, due to a poorly specific clinical presentation (splenomegaly, fatigue, cytopenias), a long delay between residence in a malaria-endemic area and onset of symptoms, and a frequent absence of parasites on conventional thin and thick blood smears. A strongly contributive laboratory parameter is the presence of high levels of total immunoglobulin M. When the diagnostic of hyper-reactive malarial splenomegaly is considered, search for anti-Plasmodium antibodies and Plasmodium nucleic acids (genus and species) by PCR is useful. Diagnosis of hyper-reactive malarial splenomegaly relies on the simultaneous presence of epidemiological, clinical, biological and follow-up findings. Regression of both splenomegaly and hypersplenism following antimalarial therapy allows the differential diagnosis with splenic lymphoma, a common complication of hyper-reactive malarial splenomegaly. Although rare in Western countries, hyper-reactive malarial splenomegaly deserves increased medical awareness to reduce the incidence of incorrect diagnosis, to prevent progression to splenic lymphoma and to avoid splenectomy. PMID:26119345

  9. Synchronous reactive programming in Ptolemy

    SciTech Connect

    Boulanger, F.; Vidal-Naquet, G.

    1996-12-31

    Synchronous reactive languages allow a high level deterministic description of reactive systems such as control-command systems. Their well defined mathematical semantics makes it possible to check formal properties on the control of a system. In previous work, we developed an object-oriented execution model for synchronous reactive modules. This model is implemented as a set of tools and a C++ class library, and allows us to use object-oriented methodologies and tools for the design of complex applications with both transformational and reactive parts. Among these design tools, the Ptolemy system stands as an object-oriented framework that supports various execution models, or {open_quotes}domains{close_quotes}. We are currently working on a translator from the output format of the Lustre and Esterel compilers to the Ptolemy language. Since no existing domain matches the reactive synchronous execution model, we also plan to develop a SEC (Synchronous Execution and Communication) domain. Such a domain will provide support for the execution of synchronous modules in Ptolemy. One of the most interesting features of Ptolemy is the communication between domains. Therefore we discuss the interface of the SEC domain to other domains to determine the meaning of communications between them. The main goal is to allow the use of synchronous reactive modules for the control of the behavior of data-flow or discrete event processes.

  10. Effects of the Vertical Cloud Structure on the Aura Ozone Monitoring Instrument (OMI) Cloud Pressure Product Derived from Rotational Raman Scattering

    NASA Astrophysics Data System (ADS)

    Vasilkov, A.; Joiner, J.; Spurr, R.; Bhartia, P. K.

    2008-05-01

    OMI cloud pressures are derived from the high frequency structure of the top-of-atmosphere (TOA) reflectance in the UV caused by rotational Raman scattering (RRS). RRS generates filling-in of Fraunhofer lines in the TOA spectrum. Cloud screens RRS in the atmosphere below the cloud thus reduces the level of the filling-in, with the magnitude of the filling-in related to cloud pressure. This effective or radiative cloud pressure (RCP) approximates an average pressure reached by backscattered solar photons. RCP characterizes how deep the solar photons penetrate the cloud and it is distinct from the physical cloud top derived from thermal infrared measurements. Comparisons of OMI cloud pressures with Aqua MODIS cloud-top pressures have shown noticeable differences for such geophysical scenarios as multiple layer clouds, deep convective clouds, and clouds with absorbing aerosol above. RT calculations were performed to simulate the effects of the vertical inhomogeneity of clouds on the retrieved cloud pressure. The RT simulations performed with using CloudSat/MODIS optical depth data show the retrieved RCP for a deep convective cloud is deep inside the cloud and significantly depends on the vertical structure. For a model of cirrus overlapping optically thick lower-level clouds, the RRS algorithm retrieves cloud pressure that may be even higher than for lower layer cloud-top pressure; this is due to scattering between the cloud layers (photon-trapping effect). The presence of absorbing aerosol above a cloud significantly can reduce the retrieved RCP. We conclude that OMI-derived RCP provides some information about the vertical extent of clouds and combination of data from A-Train sensors can potentially yield the 3-D field of cloudiness.

  11. Scattering apodizer for laser beams

    DOEpatents

    Summers, M.A.; Hagen, W.F.; Boyd, R.D.

    1984-01-01

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  12. Scattering apodizer for laser beams

    DOEpatents

    Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)

    1985-01-01

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  13. Triple?crystal x?ray diffraction analysis of reactive ion etched gallium arsenide

    E-print Network

    Wang, V. S.; Matyi, R. J.; Nordheden, Karen J.

    1994-01-01

    The effect of BCl3 reactive ion etching on the structural perfection of GaAs has been studied with diffuse x?ray scattering measurementsconducted by high?resolution triple?crystal x?ray diffraction. While using a symmetric 004 diffraction geometry...

  14. A triple sector, guided-ion-beam mass spectrometer for cluster ion and fullerene scattering

    NASA Astrophysics Data System (ADS)

    Basir, Yousef J.; Christian, James F.; Wan, Zhimin; Anderson, Scott L.

    1997-12-01

    The design and operation of a unique 5-octapole, triple sector, guided ion beam mass spectrometer is described in this article. The instrument was designed to do cluster ion reactive scattering, and the available cluster sources and the kinematics of these reactions impose some difficult design considerations. Many of these considerations also apply to ion-fullerene scattering, and this was a major application. The instrument incorporates a radio-frequency storage/thermalization trap to control the internal temperature of reactant cluster ions. Cluster ions are mass-selected by a large gap, large radius magnetic sector that can be electrically floated. Reactions are studied in a three section octapole ion guide, equipped with a reaction cell. The reaction cell also serves as an oven to generate target vapor from non-volatile materials such as fullerenes. Product mass analysis is done by a large gap, large radius double focusing mass filter, all of which floats at acceleration potential. Ions are detected by an in-line scintillation detector that can operate at voltages up to 50 kV to allow efficient detection of heavy ions. Sample results are given for reaction of carbon cluster ions with O2, and for Mo+ scattering from C60. Published by Elsevier Science B.V.

  15. Reactive Collision Avoidance Algorithm

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on-line. The optimal avoidance trajectory is implemented as a receding-horizon model predictive control law. Therefore, at each time step, the optimal avoidance trajectory is found and the first time step of its acceleration is applied. At the next time step of the control computer, the problem is re-solved and the new first time step is again applied. This continual updating allows the RCA algorithm to adapt to a colliding spacecraft that is making erratic course changes.

  16. Anisotropic Elastic Resonance Scattering model for the Neutron Transport equation

    SciTech Connect

    Mohamed Ouisloumen; Abderrafi M. Ougouag; Shadi Z. Ghrayeb

    2014-11-24

    The resonance scattering transfer cross-section has been reformulated to account for anisotropic scattering in the center-of-mass of the neutron-nucleus system. The main innovation over previous implementations is the relaxation of the ubiquitous assumption of isotropic scattering in the center-of-mass and the actual effective use of scattering angle distributions from evaluated nuclear data files in the computation of the angular moments of the resonant scattering kernels. The formulas for the high order anisotropic moments in the laboratory system are also derived. A multi-group numerical formulation is derived and implemented into a module incorporated within the NJOY nuclear data processing code. An ultra-fine energy mesh cross section library was generated using these new theoretical models and then was used for fuel assembly calculations with the PARAGON lattice physics code. The results obtained indicate a strong effect of this new model on reactivity, multi-group fluxes and isotopic inventory during depletion.

  17. Reactivation of hydroformylation catalysts

    SciTech Connect

    Babin, J.E.; Bryant, D.R.; Harrison, A.M.; Miller, D.J.

    1993-08-17

    A process is described for improving the catalytic activity of a partially deactivated solubilized rhodium-tertiary organophosphine complex hydroformylation catalyst, which comprises (1) mixing under non-hydroformylating conditions, a organic liquid medium containing said solubilized partially deactivated complex catalyst, with propargyl alcohol and a carboxylic acid of the formula RCOOH wherein R represents hydrogen or an alkyl or aryl radical to obtain a treated solubilized rhodium-tertiary organophosphine complex product solution; and (2) removing from said product solution, the carboxylic acid employed in Step (1) to obtain a rhodium-tertiary organophosphine complex hydroformylation catalyst that is more catalytically active than said partially deactivated rhodium-tertiary organophosphine complex hydroformylation catalyst starting material of Step (1).

  18. FEATURE ARTICLE Investigating the Phase-Dependent Reactivity of Chlorine Dioxide Using Resonance Raman

    E-print Network

    Reid, Philip J.

    FEATURE ARTICLE Investigating the Phase-Dependent Reactivity of Chlorine Dioxide Using Resonance-dependent reactivity of chlorine dioxide (OClO) is outlined. Specifically, resonance Raman intensity analysis (RRIA to the transport and subsequent production of atomic chlorine in the stratosphere has motivated numerous studies

  19. Single spin asymmetries in charged kaon production from semi-inclusive deep inelastic scattering on a transversely polarized He3 target

    SciTech Connect

    Zhao, Y. X.; Wang, Y.; Allada, K.; Aniol, K.; Annand, J. R.M.; Averett, T.; Benmokhtar, F.; Bertozzi, W.; Bradshaw, P. C.; Bosted, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. -P.; Chen, W.; Chirapatpimol, K.; Chudakov, E.; Cisbani, E.; Cornejo, J. C.; Cusanno, F.; Dalton, M. M.; Deconinck, W.; de Jager, C. W.; De Leo, R.; Deng, X.; Deur, A.; Ding, H.; Dolph, P. A. M.; Dutta, C.; Dutta, D.; El Fassi, L.; Frullani, S.; Gao, H.; Garibaldi, F.; Gaskell, D.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Guo, L.; Hamilton, D.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Huang, M.; Ibrahim, H. F.; Iodice, M.; Jiang, X.; Jin, G.; Jones, M. K.; Katich, J.; Kelleher, A.; Kim, W.; Kolarkar, A.; Korsch, W.; LeRose, J. J.; Li, X.; Li, Y.; Lindgren, R.; Liyanage, N.; Long, E.; Lu, H. -J.; Margaziotis, D. J.; Markowitz, P.; Marrone, S.; McNulty, D.; Meziani, Z. -E.; Michaels, R.; Moffit, B.; Muñoz Camacho, C.; Nanda, S.; Narayan, A.; Nelyubin, V.; Norum, B.; Oh, Y.; Osipenko, M.; Parno, D.; Peng, J. -C.; Phillips, S. K.; Posik, M.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Rakhman, A.; Ransome, R.; Riordan, S.; Saha, A.; Sawatzky, B.; Schulte, E.; Shahinyan, A.; Shabestari, M. H.; Širca, S.; Stepanyan, S.; Subedi, R.; Sulkosky, V.; Tang, L. -G.; Tobias, A.; Urciuoli, G. M.; Vilardi, I.; Wang, K.; Wojtsekhowski, B.; Yan, X.; Yao, H.; Ye, Y.; Ye, Z.; Yuan, L.; Zhan, X.; Zhang, Y.; Zhang, Y. -W.; Zhao, B.; Zheng, X.; Zhu, L.; Zhu, X.; Zong, X.

    2014-11-03

    We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1 < xbj<0.4 for K+ and K production. While the Collins and Sivers moments for K+ are consistent with zero within the experimental uncertainties, both moments for K favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the K+ Sivers moments are consistent with the prediction, the K results differ from the prediction at the 2-sigma level.

  20. Beam-Target Double-Spin Asymmetry ALT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized He3 Target at 1.4Q22.7 GeV2

    DOE PAGESBeta

    Huang, J.; Allada, K.; Dutta, C.; Katich, J.; Qian, X.; Wang, Y.; Zhang, Y.; Aniol, K.; Annand, J. R. M.; Averett, T.; et al

    2012-01-01

    We report the first measurement of the double-spin asymmetry ALT for charged pion electroproduction in semi-inclusive deep inelastic electron scattering on a transversely polarized 3He target. The kinematics focused on the valence quark region, 0.16 2 2. The corresponding neutron ALT asymmetries were extracted from the measured 3He asymmetries and proton/3He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g1Tq and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for ?- production on 3Hemore »and the neutron, while our ?+ asymmetries are consistent with zero.« less

  1. Ring Effect Studies: Rayleigh Scattering, including Molecular Parameters for Rotational Raman Scattering, and the Faunhofer Spectrum

    NASA Technical Reports Server (NTRS)

    Chance, K. V.; Spurr, R. J. D.

    1996-01-01

    Improved parameters for the description of Rayleigh scattering in air and for the detailed rotational Raman scattering component for scattering by O2 and N2 are presented for the wavelength range 200-1000 nm. These parameters enable more accurate calculations of bulk molecular scattering and of the 'Ring effect' for a variety of atmospheric radiative transfer and constituent retrieval applications. A solar reference spectrum with accurate absolute vacuum wavelength calibration, suitable for convolution with the rotational Raman spectrum for Ring effect calculations, has been produced and is briefly described. The solar-rotational Raman convolved product is available for fitting of atmospheric spectra.

  2. Reactive decontamination formulation

    DOEpatents

    Giletto, Anthony (College Station, TX); White, William (College Station, TX); Cisar, Alan J. (Cypress, TX); Hitchens, G. Duncan (Bryan, TX); Fyffe, James (Bryan, TX)

    2003-05-27

    The present invention provides a universal decontamination formulation and method for detoxifying chemical warfare agents (CWA's) and biological warfare agents (BWA's) without producing any toxic by-products, as well as, decontaminating surfaces that have come into contact with these agents. The formulation includes a sorbent material or gel, a peroxide source, a peroxide activator, and a compound containing a mixture of KHSO.sub.5, KHSO.sub.4 and K.sub.2 SO.sub.4. The formulation is self-decontaminating and once dried can easily be wiped from the surface being decontaminated. A method for decontaminating a surface exposed to chemical or biological agents is also disclosed.

  3. Reactive oxygen species, antioxidants and fish mitochondria.

    PubMed

    Wilhelm Filho, Danilo

    2007-01-01

    In fishes, irrespective of their thermoregulatory capacity or metabolic rate, the main physiological source of reactive oxygen species (ROS) is mitochondria. During active swimming, ROS is by an large provided by red muscle mitochondria. Other tissues such as lens, liver, heart, swimbladder, roe and blood also afford important ROS production and antioxidant levels in resting fish. A close relationship between structure and function is evident in fish mitochondrion with a surface-to-volume optimization by the size of cristae to maximize electron transfer. The mechanism of fish mitochondrial superoxide anion (O2*-) and ROS production as well as the mechanism of mitochondrial coupling and proton leak seems similar to that of mammals. Contrary to mammalian red cells, fish erythrocytes possess nuclei and mitochondria. The presence of cardiolipin and the absence of cholesterol in fish mitochondrial membranes confer a high structural flexibility. The difference in phospholipid unsaturation may explain the greater proton leak in endotherms compared to thermoconformers. The present review summarizes our current understanding in respect to comparative aspects of fish mitochondrial function, with an emphasis on the adaptations to changes in temperature, O2 availability and O2 consumption, which are generally coupled to changes in antioxidant status and ROS production. Nevertheless, most work on this fascinating area has yet to be done. The literature on the effect of xenobiotics, aquatic contamination, and aquaculture issues are not reviewed. Data on the production of NO and reactive nitrogen species (RNS), on O2 sensing and on the role of ROS and RNS in cell signalling involving fish mitochondria are almost completely lacking in the literature. PMID:17127376

  4. A Quantum Scattering Interferometer

    E-print Network

    Hart, R A; Legere, R; Gibble, K; Hart, Russell A.; Xu, Xinye; Legere, Ronald

    2007-01-01

    The collision of two ultra-cold atoms results in a quantum-mechanical superposition of two outcomes: each atom continues without scattering and each atom scatters as a spherically outgoing wave with an s-wave phase shift. The magnitude of the s-wave phase shift depends very sensitively on the interaction between the atoms. Quantum scattering and the underlying phase shifts are vitally important in many areas of contemporary atomic physics, including Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic clocks, and magnetically-tuned Feshbach resonances. Precise measurements of quantum scattering phase shifts have not been possible until now because, in scattering experiments, the number of scattered atoms depends on the s-wave phase shifts as well as the atomic density, which cannot be measured precisely. Here we demonstrate a fundamentally new type of scattering experiment that interferometrically detects the quantum scattering phase shifts of individual atoms. By performing an atomic...

  5. Imaging through scattering

    E-print Network

    Satat, Guy

    2015-01-01

    In this thesis we demonstrate novel methods to overcome optical scattering in order to resolve information about hidden scenes, in particular for biomedical applications. Imaging through scattering media has long been a ...

  6. Deleterious effects of reactive metabolites

    PubMed Central

    2010-01-01

    A number of drugs have been withdrawn from the market or severely restricted in their use because of unexpected toxicities that become apparent only after the launch of new drug entities. Circumstantial evidence suggests that, in most cases, reactive metabolites are responsible for these unexpected toxicities. In this review, a general overview of the types of reactive metabolites and the consequences of their formation are presented. The current approaches to evaluate bioactivation potential of new compounds with particular emphasis on the advantages and limitation of these procedures will be discussed. Reasonable reasons for the excellent safety record of certain drugs susceptible to bioactivation will also be explored and should provide valuable guidance in the use of reactive-metabolite assessments when nominating drug candidates for development. This will, in turn, help us to design and bring safer drugs to the market. PMID:20972370

  7. Optical Depth and Scattering Single Scatter: 0 < < 0.1

    E-print Network

    Herrick, Robert R.

    Scattering >> a · Mie Scattering a = EMR wavelength a=particle diameter #12;Types of Scatterers · Oxygen at south pole ­ light is scattered in preferred directions due to orientations of ice crystals ­ refraction

  8. Scattering from binary optics

    NASA Technical Reports Server (NTRS)

    Ricks, Douglas W.

    1993-01-01

    There are a number of sources of scattering in binary optics: etch depth errors, line edge errors, quantization errors, roughness, and the binary approximation to the ideal surface. These sources of scattering can be systematic (deterministic) or random. In this paper, scattering formulas for both systematic and random errors are derived using Fourier optics. These formulas can be used to explain the results of scattering measurements and computer simulations.

  9. Multiple Scattering Tomography

    NASA Astrophysics Data System (ADS)

    Modregger, Peter; Kagias, Matias; Peter, Silvia; Abis, Matteo; Guzenko, Vitaliy A.; David, Christian; Stampanoni, Marco

    2014-07-01

    Multiple scattering represents a challenge for numerous modern tomographic imaging techniques. In this Letter, we derive an appropriate line integral that allows for the tomographic reconstruction of angular resolved scattering distributions, even in the presence of multiple scattering. The line integral is applicable to a wide range of imaging techniques utilizing various kinds of probes. Here, we use x-ray grating interferometry to experimentally validate the framework and to demonstrate additional structural sensitivity, which exemplifies the impact of multiple scattering tomography.

  10. Role of reactive oxygen species in myocardial remodeling.

    PubMed

    Zhang, Min; Shah, Ajay M

    2007-03-01

    Adverse cardiac remodeling is a fundamental process in the progression to chronic heart failure. Although the mechanisms underlying cardiac remodeling are multi-factorial, a significant body of evidence points to the crucial roles of increased reactive oxygen species. This article reviews recent advances in delineating the different sources of production for reactive oxygen species (namely mitochondria, xanthine oxidase, uncoupled nitric oxide synthases, and NADPH oxidases) that may be involved in cardiac remodeling and the aspects of the remodeling process that they affect. These data could suggest new ways of targeting redox pathways for the prevention and treatment of adverse cardiac remodeling. PMID:17386182

  11. Grinding methods to enhance the reactivity of olivine

    SciTech Connect

    Summers, Cathy A.; Dahlin, David C.; Rush, Gilbert E.; O'Connor, William K.; Gerdemann, Stephen J.

    2004-01-01

    The Albany Research Center (ARC) conducted studies of mechanical activation by conventional and ultra-fine grinding techniques to enhance olivine reactivity in mineral carbonation reactions. Activated olivine is one of several solid feed materials used at ARC in reactions with carbon dioxide to form carbonate minerals. This paper compares grinding techniques via energy demand data and product characteristics, including particle size distributions, surface areas, full width at half maximum (FWHM) XRD analyses, and particle morphology by SEM analyses. Reactivity was gauged by percent conversion to carbonate in subsequent carbonation tests.

  12. Final rapid reactivation project environmental assessment

    SciTech Connect

    1999-02-10

    The US Department of Energy (DOE) has prepared an environmental assessment (EA) for the Rapid Reactivation Project at Sandia National Laboratories, New Mexico. The EA analyzes the potential effects of a proposal to increase production of neutron generators from the current capability of 600 units per year up to 2,000 units per year. The project would use existing buildings and infrastructure to the maximum extent possible to meet the additional production needs. The increased production levels would necessitate modifications and additions involving a total area of approximately 26,290 gross square feet at Sandia National Laboratories, New Mexico, Technical Area 1. Additional production equipment would be procured and installed. The no-action alternative would be to continue production activities at the current capability of 600 units per year. The EA analyzes effects on health, safety, and air quality, resulting from construction and operation and associated cumulative effects. A detailed description of the proposed action and its environmental consequences is presented in the EA.

  13. RADIATION FIELDS, SCATTERING AND INVERSE SCATTERING ON ASYMPTOTICALLY HYPERBOLIC MANIFOLDS

    E-print Network

    Sá Barreto, Antônio

    RADIATION FIELDS, SCATTERING AND INVERSE SCATTERING ON ASYMPTOTICALLY HYPERBOLIC MANIFOLDS ANT manifolds and to use them to study scattering and inverse scattering theories. The radiation fields on Rn, and as such can be used to define a scattering matrix. We show that this scattering matrix is equivalent

  14. Influence of CO on Titan atmospheric reactivity

    NASA Astrophysics Data System (ADS)

    Fleury, B.; Carrasco, N.; Gautier, T.; Mahjoub, A.; He, J.; Szopa, C.; Buch, A.; Cernogora, G.

    2013-12-01

    The atmosphere of Titan is mainly composed of N2 and CH4, and photochemical volatiles products CxHyNz. Most of the laboratory studies simulating Titan's atmospheric reactivity focus on the highly complex carbon and nitrogen organic chemistry leading to a production of laboratory analogues of Titan's aerosols, called Tholins [Alcouffe et al., 2010]. However, the atmosphere of Titan also contains traces of oxygen compounds. The most abudant one detected is carbon monoxyde CO with a 47 ppmv concentration measured in high stratosphere [de Kok et al., 2007]. In this work we investigate the influence of CO on the N2-CH4 reactivity. We simulate the whole reaction chains with a laboratory Radio Frequency Capacitively Coupled plasma discharge (RF CCP) gas mixture of nitrogen, methane and carbon monoxyde. In order to detect unambiguously the possible effects, CO is introduced with amounts of 0 - 1 - 2.25 - 4.5 %, larger than in Titan's atmosphere. The kinetics of the methane is monitored by mass spectrometry and the compositions of the gas phase and tholins are monitored by GC-MS and elemental analysis respectively. We find that CO modifies the composition of the gas phase with the detection of oxygenated compounds. CO decreases drastically the production efficiency of tholins, involving also a perturbation on the methane kinetics. The oxygen incorporation in tholins is found to be efficient . As a conclusion, we show that carbon monoxyde is effectively coupled with N2-CH4 chemistry and that it impacts even the solid organic aerosols. References: Alcouffe, G., et al (2010), Capacitively coupled plasma used to simulate Titan's atmospheric chemistry, Plasma Sources Science and Technology, 19(1), 015008. de Kok, R., et al. (2007), Oxygen compounds in Titan's stratosphere as observed by Cassini CIRS, Icarus, 186(2), 354-363.

  15. Synchronous Reactive Systems Stephen Edwards

    E-print Network

    Heterogeneity and Ptolemy Semantics of the SR Domain Scheduling the SR Domain 2 #12;STEPHEN EDWARDS Reactive Systems Heterogeneity and Ptolemy Semantics of the SR Domain Scheduling the SR Domain 7 #12 SYSTEMS Heterogeneity in Ptolemy Ptolemy: A system for rapid prototyping of heterogeneous systems

  16. PROCEEDINGS: MULTIPOLLUTANT SORBENT REACTIVITY WORKSHOP

    EPA Science Inventory

    The report is a compilation of technical papers and visual aids presented by representatives of industry, academia, and government agencies at a workshop on multipollutant sorbent reactivity that was held at EPA's Environmental Research Center in Research Triangle Park, NC, on Ju...

  17. Neurological Complications of VZV Reactivation

    PubMed Central

    Nagel, Maria A.

    2014-01-01

    Purpose of the review Varicella zoster virus (VZV) reactivation results in zoster, which may be complicated by postherpetic neuralgia, myelitis, meningoencephalitis and VZV vasculopathy. This review highlights the clinical features, laboratory abnormalities, imaging changes and optimal treatment of each of those conditions. Because all of these neurological disorders produced by VZV reactivation can occur in the absence of rash, the virological tests proving that VZV caused disease are discussed. Recent findings After primary infection, VZV becomes latent in ganglionic neurons along the entire neuraxis. With a decline in VZV-specific cell-mediated immunity, VZV reactivates from ganglia and travels anterograde to the skin to cause zoster, which is often complicated by postherpetic neuralgia. VZV can also travel retrograde to produce meningoencephaltis, myelitis and stroke. When these complications occur without rash, VZV-induced disease can be diagnosed by detection of VZV DNA or anti-VZV antibody in CSF and treated with intravenous acyclovir. Summary Awareness of the expanding spectrum of neurological complications caused by VZV reactivation with and without rash will improve diagnosis and treatment. PMID:24792344

  18. Electromagnetic inverse scattering

    NASA Technical Reports Server (NTRS)

    Bojarski, N. N.

    1972-01-01

    A three-dimensional electromagnetic inverse scattering identity, based on the physical optics approximation, is developed for the monostatic scattered far field cross section of perfect conductors. Uniqueness of this inverse identity is proven. This identity requires complete scattering information for all frequencies and aspect angles. A nonsingular integral equation is developed for the arbitrary case of incomplete frequence and/or aspect angle scattering information. A general closed-form solution to this integral equation is developed, which yields the shape of the scatterer from such incomplete information. A specific practical radar solution is presented. The resolution of this solution is developed, yielding short-pulse target resolution radar system parameter equations. The special cases of two- and one-dimensional inverse scattering and the special case of a priori knowledge of scatterer symmetry are treated in some detail. The merits of this solution over the conventional radar imaging technique are discussed.

  19. Evaluation of incremental reactivity and its uncertainty in Southern California.

    PubMed

    Martien, Philip T; Harley, Robert A; Milford, Jana B; Russell, Armistead G

    2003-04-15

    The incremental reactivity (IR) and relative incremental reactivity (RIR) of carbon monoxide and 30 individual volatile organic compounds (VOC) were estimated for the South Coast Air Basin using two photochemical air quality models: a 3-D, grid-based model and a vertically resolved trajectory model. Both models include an extended version of the SAPRC99 chemical mechanism. For the 3-D modeling, the decoupled direct method (DDM-3D) was used to assess reactivities. The trajectory model was applied to estimate uncertainties in reactivities due to uncertainties in chemical rate parameters, deposition parameters, and emission rates using Monte Carlo analysis with Latin hypercube sampling. For most VOC, RIRs were found to be consistent in rankings with those produced by Carter using a box model. However, 3-D simulations show that coastal regions, upwind of most of the emissions, have comparatively low IR but higher RIR than predicted by box models for C4-C5 alkenes and carbonyls that initiate the production of HOx radicals. Biogenic VOC emissions were found to have a lower RIR than predicted by box model estimates, because emissions of these VOC were mostly downwind of the areas of primary ozone production. Uncertainties in RIR of individual VOC were found to be dominated by uncertainties in the rate parameters of their primary oxidation reactions. The coefficient of variation (COV) of most RIR values ranged from 20% to 30%, whereas the COV of absolute incremental reactivity ranged from about 30% to 40%. In general, uncertainty and variability both decreased when relative rather than absolute reactivity metrics were used. PMID:12731843

  20. Production of gamma rays by pulsed laser beam Compton scattering off GeV-electrons using a non-planar four-mirror optical cavity

    E-print Network

    Akagi, T; Bonis, J; Chaikovska, I; Chiche, R; Cizeron, R; Cohen, M; Cormier, E; Cornebise, P; Delerue, N; Flaminio, R; Funahashi, S; Jehanno, D; Honda, Y; Labaye, F; Lacroix, M; Marie, R; Miyoshi, S; Nagata, S; Omori, T; Peinaud, Y; Pinard, L; Shimizu, H; Soskov, V; Takahashi, T; Tanaka, R; Terunuma, T; Urakawa, J; Variola, A; Zomer, F

    2011-01-01

    As part of the positron source R&D for future $e^+-e^-$ colliders and Compton based compact light sources, a high finesse non-planar four-mirror Fabry-Perot cavity has recently been installed at the ATF (KEK, Tsukuba, Japan). The first measurements of the gamma ray flux produced with a such cavity using a pulsed laser is presented here. We demonstrate the production of a flux of 2.7 $\\pm$ 0.2 gamma rays per bunch crossing ($\\sim3\\times10^6$ gammas per second) during the commissioning.

  1. Non-planar four-mirror optical cavity for high intensity gamma ray flux production by pulsed laser beam Compton scattering off GeV-electrons

    E-print Network

    Bonis, J; Cizeron, R; Cohen, M; Cormier, E; Cornebise, P; Delerue, N; Flaminio, R; Jehanno, D; Labaye, F; Lacroix, M; Marie, R; Mercier, B; Peinaud, Y; Pinard, L; Prevost, C; Soskov, V; Variola, A; Zomer, F

    2011-01-01

    As part of the R&D toward the production of high flux of polarised Gamma-rays we have designed and built a non-planar four-mirror optical cavity with a high finesse and operated it at a particle accelerator. We report on the main challenges of such cavity, such as the design of a suitable laser based on fiber technology, the mechanical difficulties of having a high tunability and a high mechanical stability in an accelerator environment and the active stabilization of such cavity by implementing a double feedback loop in a FPGA.

  2. Quick monitoring of pozzolanic reactivity of waste ashes.

    PubMed

    Sinthaworn, Suppachai; Nimityongskul, Pichai

    2009-05-01

    This article proposes a quick method of monitoring for pozzolanic reactivity of waste ashes by investigating the electrical conductivity of the suspension at an elevated temperature. This suspension is obtained by mixing tested pozzolan with an ordinary Portland cement (OPC) solution produced by mixing ordinary Portland cement with water. For comparison, silica fume, metakaolin, rice husk ash and river sand - whose pozzolanic reactivities range from reactive to inert - were used in the experimental investigation. The electrical conductivity of the suspension was continually recorded by using an electrical conductivity meter and stored by using a personal computer for a period of slightly over 1day. The indicative parameters that can be related to pozzolanic reactivity were discussed and analyzed in detail. It was found that it is possible to determine the pozzolanic reactivity of fly ash within 28h by using the proposed technique, as compared to 7 or 28 days for the determination of strength activity index according to ASTM. This technique would help concrete technologists to speedily investigate the quality of fly ash for use as a cement replacement in order to alleviate pollution caused by cement production and solve disposal problems of waste ashes. PMID:19131237

  3. Low-Energy Electron Scattering by Sugarcane Lignocellulosic Biomass Molecules

    NASA Astrophysics Data System (ADS)

    Oliveira, Eliane; Sanchez, Sergio; Bettega, Marcio; Lima, Marco; Varella, Marcio

    2012-06-01

    The use of second generation (SG) bioethanol instead of fossil fuels could be a good strategy to reduce greenhouse gas emissions. However, the efficient production of SG bioethanol has being a challenge to researchers around the world. The main barrier one must overcome is the pretreatment, a very important step in SG bioethanol aimed at breaking down the biomass and facilitates the extraction of sugars from the biomass. Plasma-based treatment, which can generate reactive species, could be an interesting possibility since involves low-cost atmospheric-pressure plasma. In order to offer theoretical support to this technique, the interaction of low-energy electrons from the plasma with biomass is investigated. This study was motived by several works developed by Sanche et al., in which they understood that DNA damage arises from dissociative electron attachment, a mechanism in which electrons are resonantly trapped by DNA subunits. We will present elastic cross sections for low-energy electron scattering by sugarcane biomass molecules, obtained with the Schwinger multichannel method. Our calculations indicate the formation of ?* shape resonances in the lignin subunits, while a series of broad and overlapping ?* resonances are found in cellulose and hemicellulose subunits. The presence of ?* and ?* resonances could give rise to direct and indirect dissociation pathways in biomass. Then, theoretical resonance energies can be useful to guide the plasma-based pretreatment to break down specific linkages of interest in biomass.

  4. Theoretical and Experimental Evaluation of Chemical Reactivity 

    E-print Network

    Wang, Qingsheng

    2011-10-21

    Reactive chemicals are presented widely in the chemical and petrochemical process industry. Their chemical reactivity hazards have posed a significant challenge to the industries of manufacturing, storage and transportation. ...

  5. Permeable Reactive Zones for Groundwater Remediation

    EPA Science Inventory

    The presentation will cover aspects of the application of permeable reactive zones to treat contaminated ground water. Specific field studies will be discussed covering both granular iron-based and organic carbon-based reactive barriers. Specific contaminants addressed include:...

  6. Engine combustion control via fuel reactivity stratification

    DOEpatents

    Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

    2013-12-31

    A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

  7. Engine combustion control via fuel reactivity stratification

    SciTech Connect

    Reitz, Rolf Deneys; Hanson, Reed M.; Splitter, Derek A.; Kokjohn, Sage L.

    2015-07-14

    A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

  8. C-Reactive Protein (CRP) Test

    MedlinePLUS

    ... be limited. Home Visit Global Sites Search Help? C-Reactive Protein Share this page: Was this page helpful? Also known as: CRP Formal name: C-Reactive Protein Related tests: ESR , Complement , Procalcitonin , ANA , ...

  9. Reactive oxygen species in redox cancer therapy.

    PubMed

    Tong, Lingying; Chuang, Chia-Chen; Wu, Shiyong; Zuo, Li

    2015-10-10

    The role of reactive oxygen species (ROS) in cancer cells has been intensively studied for the past two decades. Cancer cells mostly have higher basal ROS levels than their normal counterparts. The induction of ROS has been shown to be associated with cancer development, metastasis, progression, and survival. Various therapeutic approaches targeting intracellular ROS levels have yielded mixed results. As widely accepted dietary supplements, antioxidants demonstrate both ROS scavenging ability and anti-cancer characteristics. However, antioxidants may not always be safe to use since excessive intake of antioxidants could lead to serious health concerns. In this review, we have evaluated the production and scavenging systems of ROS in cells, as well as the beneficial and harmful roles of ROS in cancer cells. We also examine the effect of antioxidants in cancer treatment, the effect of combined treatment of antioxidants with traditional cancer therapies, and the side effects of excessive antioxidant intake. PMID:26187782

  10. Regulation of immune reactivity to collagen in human beings

    SciTech Connect

    Solinger, A.M.; Stobo, J.D.

    1981-08-01

    Denaturated beef collagen was tested for its ability to induce the production of leukocyte inhibition factor among the peripheral blood mononuclear cells from patients with rheumatoid arthritis and normal individuals. Responsiveness, defined as the production of leukocyte inhibition factor sufficient to cause greater than 20% inhibition of leukocyte migration, was significantly (P less than 0.001, X2 . 31.1) associated with HLA-DR4. All HLA-DR4 positive individuals, including subjects without any evidence of synovitis, were collagen responders. There was no significant (P . 0.3) difference in the absolute reactivity of HLA-DR4+ versus HLA-DR4- individuals to respond to another antigen, Candida albicans. Collagen reactivity required interactions between macrophages and T cells and was directed against determinants inherent in the linear polypeptide, (Gly-Pro)n. In 5 normal HLA-DR4- nonresponders tested, absence of discernable reactivity to collagen was associated with the presence of antigen-specific, radiosensitive suppressive T cells. These studies suggest that during the physiologic metabolism of collagen all individuals are exposed to Gly-Pro determinants normally buried in the interstices of the collagen triple helix. In individuals whose major histocompatibility complex contains genes linked to those coding for HLA-DR4, this results in the activation of reactive T cells. Conversely, in individuals lacking these genes, collagen-specific suppressive cells predominate.

  11. REGIONAL REACTIVATION OF GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    A major portion of the cost of using Granular Activated Carbon (GAC) as a water treatment unit process is associated with spent carbon replacement or reactivation. Regional reactivation or sharing a reactivation furnace among several users, has been proposed as a means of minimiz...

  12. Upscaling of reactive mass transport in fractured rocks with multimodal reactive mineral facies

    E-print Network

    Lu, Zhiming

    ), Upscaling of reactive mass transport in fractured rocks with multimodal reactive mineral facies, WaterClick Here for Full Article Upscaling of reactive mass transport in fractured rocks with multimodal reactive mineral facies Hailin Deng,1,2 Zhenxue Dai,1 Andrew Wolfsberg,1 Zhiming Lu,1 Ming Ye,2 and Paul

  13. Scattering of Skyrmions

    E-print Network

    David Foster; Steffen Krusch

    2015-06-30

    In this paper, we present a detailed study of Skyrmion-Skyrmion scattering for two $B=1$ Skyrmions in the attractive channel where we observe two different scattering regimes. For large separation, the scattering can be approximated as interacting dipoles. We give a qualitative estimate when this approximation breaks down. For small separations we observe an additional short-range repulsion which is qualitatively similar to monopole scattering. We also observe the interesting effect of "rotation without rotating" whereby two Skyrmions, whose orientations remain constant while well-separated, change their orientation after scattering. We can explain this effect by following preimages through the scattering process, thereby measuring which part of an in-coming Skyrmion forms part of an out-going Skyrmion. This leads to a new way of visualising Skyrmions. Furthermore, we consider spinning Skyrmions and find interesting trajectories.

  14. Singlet oxygen (1O) generation upon 1270 nm laser irradiation of ground state oxygen (3O) dissolved in organic solvents: Simultaneous and independent determination of 1O production rate and reactivity with chemical traps

    NASA Astrophysics Data System (ADS)

    Sivéry, A.; Anquez, F.; Pierlot, C.; Aubry, J. M.; Courtade, E.

    2013-01-01

    Direct photo-production of singlet oxygen, via 1270 nm laser excitation of molecular oxygen, has been the focus of recent articles. The chemical traps 1,3-diphenylisobenzofuran and rubrene are used to monitor singlet oxygen production in organic solvents through the O[3?g-]?O[1?g] transition. In this Letter evolution of the trap concentration is monitored continuously and we propose a new and simple method to measure singlet oxygen production rate. We derive an analytical expression for the trap disappearance rate that allows simultaneous and independent determination of the 1270 nm absorption cross section and the half quenching concentration with the chemical trap.

  15. Muon-proton Scattering

    E-print Network

    E. Borie

    2013-02-05

    A recent proposal to measure the proton form factor by means of muon-proton scattering will use muons which are not ultrarelativistic (and also not nonrelativistic). The usual equations describing the scattering cross section use the approximation that the scattered lepton (usually an electron) is ultrarelativistic, with v/c approximately equal to 1. Here the cross section is calculated for all values of the energy. It agrees with the standard result in the appropriate limit.

  16. Perceptual basis for reactive teleoperation.

    SciTech Connect

    Park, Y. S.; Ewing, T. F.; Boyle, J. M.; Yule, T. J.

    2001-08-28

    To enhance task performance in partially structured environment, enhancement of teleoperation was proposed by introducing autonomous behaviors. Such autonomy is implemented based on reactive robotic architecture, where reactive motor agents that directly couples sensory inputs and motor actions become the building blocks. To this end, presented in this paper is a perceptual basis for the motor agents. The perceptual basis consists of perceptual agents that extracts environmental information from a structured light vision system and provide action oriented perception for the corresponding motor agents. Rather than performing general scene reconstruction, a perceptual agent directly provides the motion reference for the motor behavior. Various sensory mechanisms--sensor fission, fusion, and fashion--becomes basic building blocks of the perception process. Since perception is a process deeply intertwined with the motor actions, active perception may also incorporate motor behaviors as an integral perceptual process.

  17. Reactive behavior, learning, and anticipation

    NASA Technical Reports Server (NTRS)