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Sample records for singly charged metabolites

  1. Hydrophobicity and charge shape cellular metabolite concentrations.

    Directory of Open Access Journals (Sweden)

    Arren Bar-Even

    2011-10-01

    Full Text Available What governs the concentrations of metabolites within living cells? Beyond specific metabolic and enzymatic considerations, are there global trends that affect their values? We hypothesize that the physico-chemical properties of metabolites considerably affect their in-vivo concentrations. The recently achieved experimental capability to measure the concentrations of many metabolites simultaneously has made the testing of this hypothesis possible. Here, we analyze such recently available data sets of metabolite concentrations within E. coli, S. cerevisiae, B. subtilis and human. Overall, these data sets encompass more than twenty conditions, each containing dozens (28-108 of simultaneously measured metabolites. We test for correlations with various physico-chemical properties and find that the number of charged atoms, non-polar surface area, lipophilicity and solubility consistently correlate with concentration. In most data sets, a change in one of these properties elicits a ~100 fold increase in metabolite concentrations. We find that the non-polar surface area and number of charged atoms account for almost half of the variation in concentrations in the most reliable and comprehensive data set. Analyzing specific groups of metabolites, such as amino-acids or phosphorylated nucleotides, reveals even a higher dependence of concentration on hydrophobicity. We suggest that these findings can be explained by evolutionary constraints imposed on metabolite concentrations and discuss possible selective pressures that can account for them. These include the reduction of solute leakage through the lipid membrane, avoidance of deleterious aggregates and reduction of non-specific hydrophobic binding. By highlighting the global constraints imposed on metabolic pathways, future research could shed light onto aspects of biochemical evolution and the chemical constraints that bound metabolic engineering efforts.

  2. Mass Spectrometric Method for Analyzing Metabolites in Yeast with Single Cell Sensitivity

    NARCIS (Netherlands)

    Amantonico, Andrea; Oh, Joo Yeon; Sobek, Jens; Heinemann, Matthias; Zenobi, Renato

    2008-01-01

    Getting a look-in: An optimized MALDI-MS procedure has been developed to detect endogenous primary metabolites directly in the cell extract. A detection limit corresponding to metabolites from less than a single cell has been attained, opening the door to single-cell metabolomics by mass

  3. Synthesis and single crystal X-ray analysis of two griseofulvin metabolites

    DEFF Research Database (Denmark)

    Rønnest, Mads Holger; Harris, Pernille; Gotfredsen, Charlotte Held

    2010-01-01

    The two phenols, 6-O-desmethyl griseofulvin and 4-O-desmethyl griseofulvin are metabolites of the antifungal drug griseofulvin. Herein, we present an improved synthesis of the 6-phenol derivative, and an unequivocal proof of both structures by single-crystal X-ray analysis.......The two phenols, 6-O-desmethyl griseofulvin and 4-O-desmethyl griseofulvin are metabolites of the antifungal drug griseofulvin. Herein, we present an improved synthesis of the 6-phenol derivative, and an unequivocal proof of both structures by single-crystal X-ray analysis....

  4. Multiplexed detection of metabolites of narcotic drugs from a single latent fingermark.

    Science.gov (United States)

    Hazarika, Pompi; Jickells, Sue M; Wolff, Kim; Russell, David A

    2010-11-15

    An immunoassay based technique is used for the detection of psychoactive substances in the sweat deposited within fingermarks of a narcotic drug user. Magnetic particles functionalized with antimorphine and antibenzoylecgonine antibodies were used for the detection of a metabolite of heroin (morphine) and a metabolite of cocaine (benzoylecgonine), respectively. The drug metabolites were detected individually as well as simultaneously from a single fingermark. The images of the fingermarks obtained using brightfield and fluorescence microscopy were of high evidential quality with resolution to enable identification of an individual in addition to providing information on drug usage.

  5. Deposition of diazepam and its metabolites in hair following a single dose of diazepam

    DEFF Research Database (Denmark)

    Wang, Xin; Johansen, Sys Stybe; Zhang, Yurong

    2017-01-01

    Only sporadic data are available on hair concentrations of diazepam and some of its metabolites (nordazepam, oxazepam, and temazepam) following a single controlled dose. The aim of this study was to investigate the deposition of diazepam and its metabolites in human hair after eight healthy...... volunteers (four women and four men, ages 24-26, East Asian) consumed 10 mg of diazepam. Hair was collected from all volunteers 1 month after exposure, and also 2 months post-exposure from men and 10 months post-exposure from women. Diazepam and the complete metabolite profile, including oxazepam glucuronide...... no differences by gender in the amounts of diazepam or metabolites found. The concentration of the main metabolite nordazepam was consistently higher than that of diazepam at both 1 and 2 months after consumption. Oxazepam and temazepam traces were found in some volunteers' hair, but the glucuronides were...

  6. A singly charged ion source for radioactive 11C ion acceleration

    Science.gov (United States)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K.

    2016-02-01

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  7. Macroscopic charge quantization in single-electron devices

    NARCIS (Netherlands)

    Burmistrov, I.S.; Pruisken, A.M.M.

    2010-01-01

    In a recent paper by the authors [I. S. Burmistrov and A. M. M. Pruisken, Phys. Rev. Lett. 101, 056801 (2008)] it was shown that single-electron devices (single-electron transistor or SET) display "macroscopic charge quantization" which is completely analogous to the quantum Hall effect observed on

  8. Control of single-electron charging of metallic nanoparticles onto amorphous silicon surface.

    Science.gov (United States)

    Weis, Martin; Gmucová, Katarína; Nádazdy, Vojtech; Capek, Ignác; Satka, Alexander; Kopáni, Martin; Cirák, Július; Majková, Eva

    2008-11-01

    Sequential single-electron charging of iron oxide nanoparticles encapsulated in oleic acid/oleyl amine envelope and deposited by the Langmuir-Blodgett technique onto Pt electrode covered with undoped hydrogenated amorphous silicon film is reported. Single-electron charging (so-called quantized double-layer charging) of nanoparticles is detected by cyclic voltammetry as current peaks and the charging effect can be switched on/off by the electric field in the surface region induced by the excess of negative/positive charged defect states in the amorphous silicon layer. The particular charge states in amorphous silicon are created by the simultaneous application of a suitable bias voltage and illumination before the measurement. The influence of charged states on the electric field in the surface region is evaluated by the finite element method. The single-electron charging is analyzed by the standard quantized double layer model as well as two weak-link junctions model. Both approaches are in accordance with experiment and confirm single-electron charging by tunnelling process at room temperature. This experiment illustrates the possibility of the creation of a voltage-controlled capacitor for nanotechnology.

  9. Deterministic Electrical Charge-State Initialization of Single Nitrogen-Vacancy Center in Diamond

    Directory of Open Access Journals (Sweden)

    Y. Doi

    2014-03-01

    Full Text Available Apart from applications in classical information-processing devices, the electrical control of atomic defects in solids at room temperature will have a tremendous impact on quantum devices that are based on such defects. In this study, we demonstrate the electrical manipulation of individual prominent representatives of such atomic solid-state defects, namely, the negative charge state of single nitrogen-vacancy defect centers (NV^{−} in diamond. We experimentally demonstrate, deterministic, purely electrical charge-state initialization of individual NV centers. The NV centers are placed in the intrinsic region of a p-i-n diode structure that facilitates the delivery of charge carriers to the defect for charge-state switching. The charge-state dynamics of a single NV center were investigated by time-resolved measurements and a nondestructive single-shot readout of the charge state. Fast charge-state switching rates (from negative to neutrally charged defects, which are greater than 0.72 ± 0.10  μs^{−1}, were realized. Furthermore, in no-operation mode, the realized charge states were stable for presumably much more than 0.45 s. We believe that the results obtained are useful not only for ultrafast electrical control of qubits, long T_{2} quantum memory, and quantum sensors associated with single NV centers but also for classical memory devices based on single atomic storage bits working under ambient conditions.

  10. Single- and double-charge exchange at low pion energies

    International Nuclear Information System (INIS)

    Baer, H.W.

    1991-01-01

    A review is given of pion single- and double-charge exchange reactions at incident energies of 25 to 65 MeV leading to isobaric analog states, and in the case of double-charge exchange leading to the ground state of the residual nucleus. The crucial role of the higher nuclear transparency at low pion energies for the analysis of the data in terms of single and double scattering is demonstrated. The large effects on double-charge exchange produced by the spatial correlations in nuclear wave functions are evident. The data on 1f 7/2 nuclei at 35 MeV are used to establish the general validity of a shell-model-based two-amplitude model for these transitions. Recent measurements of the energy dependence between 25 and 65 MeV of double-charge exchange cross sections at forward angles are presented and discussed. 33 refs., 19 figs

  11. Charge collection and SEU (Single Event Upset) mechanisms

    International Nuclear Information System (INIS)

    Musseau, O.

    1994-01-01

    The purpose of this paper is to review the mechanisms of single event upset in microelectronic devices due to interaction with cosmic ions. Experimental and theoretical results are presented, and actual questions and problems are discussed. A brief introduction recalls the creation of the dense plasma of electron-hole pairs along the ion track. The basic processes for charge collection in a simple np junction (drift and diffusion) are presented. The funneling-field effect is discussed and experimental results are compared to numerical simulations and semi-empirical models. Charge collection in actual microelectronic structures is then presented. Single event upset of memory cells is discussed, based on numerical and experimental data. The main parameters for device characterization are presented. From the physical interpretation of charge collection mechanisms, the intrinsic sensitivity of various microelectronic technologies is determined and compared to experimental data. Scaling laws and future trends are discussed. (author)

  12. Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

    Science.gov (United States)

    Ventrella, Emanuela; Adamski, Zbigniew; Chudzińska, Ewa; Miądowicz-Kobielska, Mariola; Marciniak, Paweł; Büyükgüzel, Ender; Büyükgüzel, Kemal; Erdem, Meltem; Falabella, Patrizia; Scrano, Laura; Bufo, Sabino Aurelio

    2016-01-01

    Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed) generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture.

  13. Solanum tuberosum and Lycopersicon esculentum Leaf Extracts and Single Metabolites Affect Development and Reproduction of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Emanuela Ventrella

    Full Text Available Glycoalkaloids are secondary metabolites commonly found in Solanaceae plants. They have anti-bacterial, anti-fungal and insecticidal activities. In the present study we examine the effects of potato and tomato leaf extracts and their main components, the glycoalkaloids α-solanine, α-chaconine and α-tomatine, on development and reproduction of Drosophila melanogaster wild-type flies at different stages. Parental generation was exposed to five different concentrations of tested substances. The effects were examined also on the next, non-exposed generation. In the first (exposed generation, addition of each extract reduced the number of organisms reaching the pupal and imaginal stages. Parent insects exposed to extracts and metabolites individually applied showed faster development. However, the effect was weaker in case of single metabolites than in case of exposure to extracts. An increase of developmental rate was also observed in the next, non-exposed generation. The imagoes of both generations exposed to extracts and pure metabolites showed some anomalies in body size and malformations, such as deformed wings and abdomens, smaller black abdominal zone. Our results further support the current idea that Solanaceae can be an impressive source of molecules, which could efficaciously be used in crop protection, as natural extract or in formulation of single pure metabolites in sustainable agriculture.

  14. The single-sink fixed-charge transportation problem: Applications and solution methods

    DEFF Research Database (Denmark)

    Goertz, Simon; Klose, Andreas

    2007-01-01

    The single-sink fixed-charge transportation problem (SSFCTP) consists in finding a minimum cost flow from a number of supplier nodes to a single demand node. Shipping costs comprise costs proportional to the amount shipped as well as a fixed-charge. Although the SSFCTP is an important special case...... of the well-known fixed-charge transportation problem, just a few methods for solving this problem have been proposed in the literature. After summarising some applications of this problem arising in manufacturing and transportation, we give an overview on approximation algorithms and worst-case results...

  15. Modulation and Control of Charge Transport Through Single-Molecule Junctions.

    Science.gov (United States)

    Wang, Kun; Xu, Bingqian

    2017-02-01

    The ability to modulate and control charge transport though single-molecule junction devices is crucial to achieving the ultimate goal of molecular electronics: constructing real-world-applicable electronic components from single molecules. This review aims to highlight the progress made in single-molecule electronics, emphasizing the development of molecular junction electronics in recent years. Among many techniques that attempt to wire a molecule to metallic electrodes, the single-molecule break junction (SMBJ) technique is one of the most reliable and tunable experimental platforms for achieving metal-molecule-metal configurations. It also provides great freedom to tune charge transport through the junction. Soon after the SMBJ technique was introduced, it was extensively used to measure the conductances of individual molecules; however, different conductances were obtained for the same molecule, and it proved difficult to interpret this wide distribution of experimental data. This phenomenon was later found to be mainly due to a lack of precise experimental control and advanced data analysis methods. In recent years, researchers have directed considerable effort into advancing the SMBJ technique by gaining a deeper physical understanding of charge transport through single molecules and thus enhancing its potential applicability in functional molecular-scale electronic devices, such as molecular diodes and molecular transistors. In parallel with that research, novel data analysis methods and approaches that enable the discovery of hidden yet important features in the data are being developed. This review discusses various aspects of molecular junction electronics, from the initial goal of molecular electronics, the development of experimental techniques for creating single-molecule junctions and determining single-molecule conductance, to the characterization of functional current-voltage features and the investigation of physical properties other than charge

  16. MetRxn: a knowledgebase of metabolites and reactions spanning metabolic models and databases

    Directory of Open Access Journals (Sweden)

    Kumar Akhil

    2012-01-01

    Full Text Available Abstract Background Increasingly, metabolite and reaction information is organized in the form of genome-scale metabolic reconstructions that describe the reaction stoichiometry, directionality, and gene to protein to reaction associations. A key bottleneck in the pace of reconstruction of new, high-quality metabolic models is the inability to directly make use of metabolite/reaction information from biological databases or other models due to incompatibilities in content representation (i.e., metabolites with multiple names across databases and models, stoichiometric errors such as elemental or charge imbalances, and incomplete atomistic detail (e.g., use of generic R-group or non-explicit specification of stereo-specificity. Description MetRxn is a knowledgebase that includes standardized metabolite and reaction descriptions by integrating information from BRENDA, KEGG, MetaCyc, Reactome.org and 44 metabolic models into a single unified data set. All metabolite entries have matched synonyms, resolved protonation states, and are linked to unique structures. All reaction entries are elementally and charge balanced. This is accomplished through the use of a workflow of lexicographic, phonetic, and structural comparison algorithms. MetRxn allows for the download of standardized versions of existing genome-scale metabolic models and the use of metabolic information for the rapid reconstruction of new ones. Conclusions The standardization in description allows for the direct comparison of the metabolite and reaction content between metabolic models and databases and the exhaustive prospecting of pathways for biotechnological production. This ever-growing dataset currently consists of over 76,000 metabolites participating in more than 72,000 reactions (including unresolved entries. MetRxn is hosted on a web-based platform that uses relational database models (MySQL.

  17. Charge collection measurements in single-type column 3D sensors

    International Nuclear Information System (INIS)

    Scaringella, M.; Polyakov, A.; Sadrozinski, H.F.-W.; Bruzzi, M.; Tosi, C.; Boscardin, M.; Piemonte, C.; Pozza, A.; Ronchin, S.; Zorzi, N.; Dalla Betta, G.-F.

    2007-01-01

    We report on charge collection studies on 3D silicon detectors of single-type column n-diffusions in p-substrate, configured either as strip or as pad detectors. The charge is generated by penetrating beta particles from a 90 Sr source which, together with a scintillation counter, serves as an electron telescope. The charge collection as a function of bias voltage is compared with the depletion thickness derived from the measured C-V characteristics

  18. Single charging events on colloidal particles in a nonpolar liquid with surfactant

    Science.gov (United States)

    Schreuer, Caspar; Vandewiele, Stijn; Brans, Toon; Strubbe, Filip; Neyts, Kristiaan; Beunis, Filip

    2018-01-01

    Electrical charging of colloidal particles in nonpolar liquids due to surfactant additives is investigated intensively, motivated by its importance in a variety of applications. Most methods rely on average electrophoretic mobility measurements of many particles, which provide only indirect information on the charging mechanism. In the present work, we present a method that allows us to obtain direct information on the charging mechanism, by measuring the charge fluctuations on individual particles with a precision higher than the elementary charge using optical trapping electrophoresis. We demonstrate the capabilities of the method by studying the influence of added surfactant OLOA 11000 on the charging of single colloidal PMMA particles in dodecane. The particle charge and the frequency of charging events are investigated both below and above the critical micelle concentration (CMC) and with or without applying a DC offset voltage. It is found that at least two separate charging mechanisms are present below the critical micelle concentration. One mechanism is a process where the particle is stripped from negatively charged ionic molecules. An increase in the charging frequency with increased surfactant concentration suggests a second mechanism that involves single surfactant molecules. Above the CMC, neutral inverse micelles can also be involved in the charging process.

  19. Absolute beam-charge measurement for single-bunch electron beams

    International Nuclear Information System (INIS)

    Suwada, Tsuyoshi; Ohsawa, Satoshi; Furukawa, Kazuro; Akasaka, Nobumasa

    2000-01-01

    The absolute beam charge of a single-bunch electron beam with a pulse width of 10 ps and that of a short-pulsed electron beam with a pulse width of 1 ns were measured with a Faraday cup in a beam test for the KEK B-Factory (KEKB) injector linac. It is strongly desired to obtain a precise beam-injection rate to the KEKB rings, and to estimate the amount of beam loss. A wall-current monitor was also recalibrated within an error of ±2%. This report describes the new results for an absolute beam-charge measurement for single-bunch and short-pulsed electron beams, and recalibration of the wall-current monitors in detail. (author)

  20. Charge transport through image charged stabilized states in a single molecule single electron transistor device

    International Nuclear Information System (INIS)

    Hedegard, Per; Bjornholm, Thomas

    2005-01-01

    The present paper gives an elaborate theoretical description of a new molecular charge transport mechanism applying to a single molecule trapped between two macroscopic electrodes in a solid state device. It is shown by a Hubbard type model of the electronic and electrostatic interactions, that the close proximity of metal electrodes may allow electrons to tunnel from the electrode directly into very localized image charge stabilized states on the molecule. Due to this mechanism, an exceptionally large number of redox states may be visited within an energy scale which would normally not allow the molecular HOMO-LUMO gap to be transversed. With a reasonable set of parameters, a good fit to recent experimental values may be obtained. The theoretical model is furthermore used to search for the physical boundaries of this effect, and it is found that a rather narrow geometrical space is available for the new mechanism to work: in the specific case of oligophenylenevinylene molecules recently explored in such devices several atoms in the terminal benzene rings need to be at van der Waal's distance to the electrode in order for the mechanism to work. The model predicts, that chemisorption of the terminal benzene rings too gold electrodes will impede the image charge effect very significantly because the molecule is pushed away from the electrode by the covalent thiol-gold bond

  1. Single-charge craters excavated during subsurface high-explosive experiments at Big Black Test Site, Mississippi

    International Nuclear Information System (INIS)

    Woodruff, W.R.; Bryan, J.B.

    1978-01-01

    Single-charge and row-charge subsurface cratering experiments were performed to learn how close-spacing enhances single-crater dimensions. Our first experimental phase established cratering curves for 60-lb charges of the chemical explosive. For the second phase, to be described in a subsequent report, the Row-cratering experiments were designed and executed. This data report contains excavated dimensions and auxiliary data for the single-charge cratering experiments. The dimensions for the row-charge experiments will be in the other report. Significant changes in the soil's water content appeared to cause a variability in the excavated dimensions. This variability clouded the interpretation and application of the cratering curves obtained

  2. Nuclear structure and the single charge exchange

    International Nuclear Information System (INIS)

    Oset, E.; Strottman, D.

    1979-01-01

    The influence of nuclear structure on meson-induced single-charge-exchange reactions on light nuclei is discussed within the context of the Glauber approximation. Selection rules which are expected to be approximately obeyed in elastic and inelastic pion and kaon scattering are proposed. Theoretical predictions are presented for (π + ,π 0 ) and (K + ,K 0 ) reactions on 13 C. 14 figures

  3. Detection of charged particles with a methylammonium lead tribromide perovskite single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiang [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Wei, Haotong; Wei, Wei [Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Chuirazzi, William; DeSantis, Dylan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States); Huang, Jinsong, E-mail: jhuang2@unl.edu [Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Cao, Lei, E-mail: cao.152@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)

    2017-03-11

    Methylammonium lead tribromide (MAPbBr{sub 3}) perovskite crystals have attracted significant attention due to their attractive performance in various optoelectronic applications such as solar cells, light-emitting devices, photodetectors, and recently in X-ray detectors. In this study, we demonstrate a possible use of perovskite-based devices for detection of charged particles (which can be applied in basic scientific research, health physics, and environmental analysis) and investigate the mechanism of fundamental charge transport inside perovskite crystals. It was found that inexpensive MAPbBr{sub 3} single crystals could be used for measuring the energy spectrum of charged particles through direct collection of the produced charge. After fitting the plot of the centroid peak position versus voltage with the Hecht equation for single-polarity charge transport, the obtained hole mobility-lifetime product was in the range of (0.4–1.6)×10{sup −3} cm{sup 2}/V.

  4. Detection of charged particles with a methylammonium lead tribromide perovskite single crystal

    International Nuclear Information System (INIS)

    Xu, Qiang; Wei, Haotong; Wei, Wei; Chuirazzi, William; DeSantis, Dylan; Huang, Jinsong; Cao, Lei

    2017-01-01

    Methylammonium lead tribromide (MAPbBr_3) perovskite crystals have attracted significant attention due to their attractive performance in various optoelectronic applications such as solar cells, light-emitting devices, photodetectors, and recently in X-ray detectors. In this study, we demonstrate a possible use of perovskite-based devices for detection of charged particles (which can be applied in basic scientific research, health physics, and environmental analysis) and investigate the mechanism of fundamental charge transport inside perovskite crystals. It was found that inexpensive MAPbBr_3 single crystals could be used for measuring the energy spectrum of charged particles through direct collection of the produced charge. After fitting the plot of the centroid peak position versus voltage with the Hecht equation for single-polarity charge transport, the obtained hole mobility-lifetime product was in the range of (0.4–1.6)×10"−"3 cm"2/V.

  5. Charge Effects on the Efflorescence in Single Levitated Droplets.

    Science.gov (United States)

    Hermann, Gunter; Zhang, Yan; Wassermann, Bernhard; Fischer, Henry; Quennet, Marcel; Rühl, Eckart

    2017-09-14

    The influence of electrical excess charges on the crystallization from supersaturated aqueous sodium chloride solutions is reported. This is accomplished by efflorescence studies on single levitated microdroplets using optical and electrodynamic levitation. Specifically, a strong increase in efflorescence humidity is observed as a function of the droplet's negative excess charge, ranging up to -2.1 pC, with a distinct threshold behavior, increasing the relative efflorescence humidity, at which spontaneous nucleation occurs, from 44% for the neutral microparticle to 60%. These findings are interpreted by using molecular dynamics simulations for determining plausible structural patterns located near the particle surface that could serve as suitable precursors for the formation of critical clusters overcoming the nucleation barrier. These results, facilitating heterogeneous nucleation in the case of negatively charged microparticles, are compared to recent work on charge-induced nucleation of neat supercooled water, where a distinctly different nucleation behavior as a function of droplet charge has been observed.

  6. Single-charge tunneling in ambipolar silicon quantum dots

    NARCIS (Netherlands)

    Müller, Filipp

    2015-01-01

    Spin qubits in coupled quantum dots (QDs) are promising for future quantum information processing (QIP). A quantum bit (qubit) is the quantum mechanical analogon of a classical bit. In general, each quantum mechanical two-level system can represent a qubit. For the spin of a single charge carrier

  7. A Study of Charged Current Single Charged Pion Productions on Carbon in a Few-GeV Neutrino Beam

    Energy Technology Data Exchange (ETDEWEB)

    Hiraide, Katsuki [Kyoto Univ. (Japan)

    2009-01-01

    Understanding single charged pion production via neutrino-nucleus charged current interaction in the neutrino energy region of a few GeV is essential for future neutrino oscillation experiments since this process is a dominant background for vμ → vx oscillation measurements. There are two contributions to this process: single pion production via baryonic resonance (vμN → μ-+) and coherent pion production interacting with the entire nucleus (vμA → μ-+), where N is nucleon in the nucleus and A is the nucleus. The purpose of the study presented in this thesis is a precise measurement of charged current single charged pion productions, resonant and coherent pion productions, with a good final state separation in the neutrino energy region of a few GeV. In this thesis, we focus on the study of charged current coherent pion production from muon neutrinos scattering on carbon, vμ 12C → μ-12+, in the SciBooNE experiment. This is motivated by the fact that without measuring this component first, the precise determination of resonant pion production cross section can not be achieved since the contribution of coherent pion production in the region of small muon scattering angle is not small. Furthermore, the coherent process is particularly interesting because it is deeply rooted in fundamental physics via Adler's partially conserved axial-vector current theorem. We took data from June 2007 until August 2008, in both the neutrino and antineutrino beam. In total, 2.52 x 1020 protons on target were collected. We have performed a search for charged current coherent pion production by using SciBooNE's full neutrino data set, corresponding to 0.99 x 1020 protons on target. No evidence for coherent pion production is observed. We set 90% confidence level upper limits on the cross section ratio

  8. Pharmacokinetics of dextromethorphan and its metabolites in horses following a single oral administration.

    Science.gov (United States)

    Corado, Carley R; McKemie, Daniel S; Knych, Heather K

    2017-06-01

    Dextromethorphan is an N-methyl-D-aspartate (NMDA) non-competitive antagonist commonly used in human medicine as an antitussive. Dextromethorphan is metabolized in humans by cytochrome P450 2D6 into dextrorphan, which is reported to be more potent than the parent compound. The goal of this study is to describe the metabolism of and determine the pharmacokinetics of dextromethorphan and its major metabolites following oral administration to horses. A total of 23 horses received a single oral dose of 2 mg/kg. Blood samples were collected at time 0 and at various times up to 96 h post drug administration. Urine samples were collected from 12 horses up to 120 h post administration. Plasma and urine samples were analyzed using liquid chromatography-mass spectrometry, and the resulting data analyzed using non-compartmental analysis. The C max , T max , and the t 1/2 of dextromethorphan were 519.4 ng/mL, 0.55 h, and 12.4 h respectively. The area under the curve of dextromethorphan, free dextrorphan, and conjugated dextrorphan were 563.8, 2.19, and 6,691 h*ng/mL respectively. In addition to free and glucuronidated dextrorphan, several additional glucuronide metabolites were identified in plasma, including hydroxyl-desmethyl dextrorphan, desmethyl dextrorphan, and three forms of hydroxylated dextrorphan. Dextromethorphan was found to be eliminated from the urine predominately as the O-demethylated metabolite, dextrorphan. Several additional metabolites including several novel hydroxy-dextrorphan metabolites were also detected in the urine in both free and glucuronidated forms. No significant undesirable behavioural effects were noted throughout the duration of the study. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Direct observation of single-charge-detection capability of nanowire field-effect transistors.

    Science.gov (United States)

    Salfi, J; Savelyev, I G; Blumin, M; Nair, S V; Ruda, H E

    2010-10-01

    A single localized charge can quench the luminescence of a semiconductor nanowire, but relatively little is known about the effect of single charges on the conductance of the nanowire. In one-dimensional nanostructures embedded in a material with a low dielectric permittivity, the Coulomb interaction and excitonic binding energy are much larger than the corresponding values when embedded in a material with the same dielectric permittivity. The stronger Coulomb interaction is also predicted to limit the carrier mobility in nanowires. Here, we experimentally isolate and study the effect of individual localized electrons on carrier transport in InAs nanowire field-effect transistors, and extract the equivalent charge sensitivity. In the low carrier density regime, the electrostatic potential produced by one electron can create an insulating weak link in an otherwise conducting nanowire field-effect transistor, modulating its conductance by as much as 4,200% at 31 K. The equivalent charge sensitivity, 4 × 10(-5) e Hz(-1/2) at 25 K and 6 × 10(-5) e Hz(-1/2) at 198 K, is orders of magnitude better than conventional field-effect transistors and nanoelectromechanical systems, and is just a factor of 20-30 away from the record sensitivity for state-of-the-art single-electron transistors operating below 4 K (ref. 8). This work demonstrates the feasibility of nanowire-based single-electron memories and illustrates a physical process of potential relevance for high performance chemical sensors. The charge-state-detection capability we demonstrate also makes the nanowire field-effect transistor a promising host system for impurities (which may be introduced intentionally or unintentionally) with potentially long spin lifetimes, because such transistors offer more sensitive spin-to-charge conversion readout than schemes based on conventional field-effect transistors.

  10. Single-crystal charge transfer interfaces for efficient photonic devices (Conference Presentation)

    Science.gov (United States)

    Alves, Helena; Pinto, Rui M.; Maçôas, Ermelinda M. S.; Baleizão, Carlos; Santos, Isabel C.

    2016-09-01

    Organic semiconductors have unique optical, mechanical and electronic properties that can be combined with customized chemical functionality. In the crystalline form, determinant features for electronic applications such as molecular purity, the charge mobility or the exciton diffusion length, reveal a superior performance when compared with materials in a more disordered form. Combining crystals of two different conjugated materials as even enable a new 2D electronic system. However, the use of organic single crystals in devices is still limited to a few applications, such as field-effect transistors. In 2013, we presented the first system composed of single-crystal charge transfer interfaces presenting photoconductivity behaviour. The system composed of rubrene and TCNQ has a responsivity reaching 1 A/W, corresponding to an external quantum efficiency of nearly 100%. A similar approach, with a hybrid structure of a PCBM film and rubrene single crystal also presents high responsivity and the possibility to extract excitons generated in acceptor materials. This strategy led to an extended action towards the near IR. By adequate material design and structural organisation of perylediimides, we demonstrate that is possible to improve exciton diffusion efficiency. More recently, we have successfully used the concept of charge transfer interfaces in phototransistors. These results open the possibility of using organic single-crystal interfaces in photonic applications.

  11. Anisotropic charge transport in large single crystals of π-conjugated organic molecules.

    Science.gov (United States)

    Hourani, Wael; Rahimi, Khosrow; Botiz, Ioan; Koch, Felix Peter Vinzenz; Reiter, Günter; Lienerth, Peter; Heiser, Thomas; Bubendorff, Jean-Luc; Simon, Laurent

    2014-05-07

    The electronic properties of organic semiconductors depend strongly on the nature of the molecules, their conjugation and conformation, their mutual distance and the orientation between adjacent molecules. Variations of intramolecular distances and conformation disturb the conjugation and perturb the delocalization of charges. As a result, the mobility considerably decreases compared to that of a covalently well-organized crystal. Here, we present electrical characterization of large single crystals made of the regioregular octamer of 3-hexyl-thiophene (3HT)8 using a conductive-atomic force microscope (C-AFM) in air. We find a large anisotropy in the conduction with charge mobility values depending on the crystallographic orientation of the single crystal. The smaller conduction is in the direction of π-π stacking (along the long axis of the single crystal) with a mobility value in the order of 10(-3) cm(2) V(-1) s(-1), and the larger one is along the molecular axis (in the direction normal to the single crystal surface) with a mobility value in the order of 0.5 cm(2) V(-1) s(-1). The measured current-voltage (I-V) curves showed that along the molecular axis, the current followed an exponential dependence corresponding to an injection mode. In the π-π stacking direction, the current exhibits a space charge limited current (SCLC) behavior, which allows us to estimate the charge carrier mobility.

  12. Charge collection measurements with p-type Magnetic Czochralski silicon single pad detectors

    International Nuclear Information System (INIS)

    Tosi, C.; Bruzzi, M.; Macchiolo, A.; Scaringella, M.; Petterson, M.K.; Sadrozinski, H.F.-W.; Betancourt, C.; Manna, N.; Creanza, D.; Boscardin, M.; Piemonte, C.; Zorzi, N.; Borrello, L.; Messineo, A.

    2007-01-01

    The charge collected from beta source particles in single pad detectors produced on p-type Magnetic Czochralski (MCz) silicon wafers has been measured before and after irradiation with 26 MeV protons. After a 1 MeV neutron equivalent fluence of 1x10 15 cm -2 the collected charge is reduced to 77% at bias voltages below 900 V. This result is compared with previous results from charge collection measurements

  13. Single Photon, Spin, and Charge in Diamond Semiconductor at room temperature

    International Nuclear Information System (INIS)

    Yuki Doi

    2014-01-01

    The nitrogen-vacancy (NV) center in diamond is a promising candidate for a qubit driven at room temperature. In order to derive potential of NV center, manipulation of their charge state is a very important topic. Here we succeeded to electrically control between single NV-/NV0 by means of current injection. This method allows us to very stable charge state control. (author)

  14. The Welsh Single-Use Carrier Bag Charge and behavioural spillover

    OpenAIRE

    Thomas, Gregory O.; Poortinga, Wouter; Sautkina, Elena

    2016-01-01

    A Single-Use Carrier Bag Charge (SUCBC) requires bags to be sold for a small fee, instead of free of charge. SUCBCs may produce ‘spillover’ effects, where other pro-environmental attitudes and behaviours could increase or decrease. We investigate the 2011 Welsh SUCBC, and whether spillover occurs in other behaviours and attitudes. Using the Understanding Society Survey (n = 17,636), results show that use of own shopping bags increased in Wales, compared to England and Scotland. Increased use ...

  15. Device simulation of charge collection and single-event upset

    International Nuclear Information System (INIS)

    Dodd, P.E.

    1996-01-01

    In this paper the author reviews the current status of device simulation of ionizing-radiation-induced charge collection and single-event upset (SEU), with an emphasis on significant results of recent years. The author presents an overview of device-modeling techniques applicable to the SEU problem and the unique challenges this task presents to the device modeler. He examines unloaded simulations of radiation-induced charge collection in simple p/n diodes, SEU in dynamic random access memories (DRAM's), and SEU in static random access memories (SRAM's). The author concludes with a few thoughts on future issues likely to confront the SEU device modeler

  16. Charged-particle spectroscopy in organic semiconducting single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ciavatti, A.; Basiricò, L.; Fraboni, B. [Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy); Sellin, P. J. [Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Fraleoni-Morgera, A. [ELETTRA-Sincrotrone Trieste, Strada Statale 14, Km 163.5, Basovizza, Trieste (Italy); Department of Engineering and Architecture, University of Trieste, V. Valerio 10, 34100 Trieste (Italy); CNR-Nano S3 Institute, Via Campi 213/A, 41125 Modena (Italy)

    2016-04-11

    The use of organic materials as radiation detectors has grown, due to the easy processability in liquid phase at room temperature and the possibility to cover large areas by means of low cost deposition techniques. Direct charged-particle detectors based on solution-grown Organic Semiconducting Single Crystals (OSSCs) are shown to be capable to detect charged particles in pulse mode, with very good peak discrimination. The direct charged-particle detection in OSSCs has been assessed both in the planar and in the vertical axes, and a digital pulse processing algorithm has been used to perform pulse height spectroscopy and to study the charge collection efficiency as a function of the applied bias voltage. Taking advantage of the charge spectroscopy and the good peak discrimination of pulse height spectra, an Hecht-like behavior of OSSCs radiation detectors is demonstrated. It has been possible to estimate the mobility-lifetime value in organic materials, a fundamental parameter for the characterization of radiation detectors, whose results are equal to μτ{sub coplanar} = (5 .5 ± 0.6 ) × 10{sup −6} cm{sup 2}/V and μτ{sub sandwich} = (1 .9 ± 0.2 ) × 10{sup −6} cm{sup 2}/V, values comparable to those of polycrystalline inorganic detectors. Moreover, alpha particles Time-of-Flight experiments have been carried out to estimate the drift mobility value. The results reported here indicate how charged-particle detectors based on OSSCs possess a great potential as low-cost, large area, solid-state direct detectors operating at room temperature. More interestingly, the good detection efficiency and peak discrimination observed for charged-particle detection in organic materials (hydrogen-rich molecules) are encouraging for their further exploitation in the detection of thermal and high-energy neutrons.

  17. Cavity Cooling a Single Charged Levitated Nanosphere

    Science.gov (United States)

    Millen, J.; Fonseca, P. Z. G.; Mavrogordatos, T.; Monteiro, T. S.; Barker, P. F.

    2015-03-01

    Optomechanical cavity cooling of levitated objects offers the possibility for laboratory investigation of the macroscopic quantum behavior of systems that are largely decoupled from their environment. However, experimental progress has been hindered by particle loss mechanisms, which have prevented levitation and cavity cooling in a vacuum. We overcome this problem with a new type of hybrid electro-optical trap formed from a Paul trap within a single-mode optical cavity. We demonstrate a factor of 100 cavity cooling of 400 nm diameter silica spheres trapped in vacuum. This paves the way for ground-state cooling in a smaller, higher finesse cavity, as we show that a novel feature of the hybrid trap is that the optomechanical cooling becomes actively driven by the Paul trap, even for singly charged nanospheres.

  18. Superconducting and charge density wave transition in single crystalline LaPt2Si2

    Science.gov (United States)

    Gupta, Ritu; Dhar, S. K.; Thamizhavel, A.; Rajeev, K. P.; Hossain, Z.

    2017-06-01

    We present results of our comprehensive studies on single crystalline LaPt2Si2. Pronounced anomaly in electrical resistivity and heat capacity confirms the bulk nature of superconductivity (SC) and charge density wave (CDW) transition in the single crystals. While the charge density wave transition temperature is lower, the superconducting transition temperature is higher in single crystal compared to the polycrystalline sample. This result confirms the competing nature of CDW and SC. Another important finding is the anomalous temperature dependence of upper critical field H C2(T). We also report the anisotropy in the transport and magnetic measurements of the single crystal.

  19. Algorithms for solving the single-sink fixed-charge transportation problem

    DEFF Research Database (Denmark)

    Klose, Andreas

    2006-01-01

    The single-sink fixed-charge transportation problem is an important subproblem of the fixed-charge transportation problem. Just a few methods have been proposed in the literature to solve this problem. In this paper, solution approaches based on dynamic programming and implicit enumeration...... are revisited. It is shown how the problem size as well as the search space of a recently published dynamic programming method can be reduced by exploiting reduced cost information. Additionally, a further implicit enumeration approach relying on solution concepts for the binary knapsack problem is introduced...

  20. Ionization detector, electrode configuration and single polarity charge detection method

    Science.gov (United States)

    He, Z.

    1998-07-07

    An ionization detector, an electrode configuration and a single polarity charge detection method each utilize a boundary electrode which symmetrically surrounds first and second central interlaced and symmetrical electrodes. All of the electrodes are held at a voltage potential of a first polarity type. The first central electrode is held at a higher potential than the second central or boundary electrodes. By forming the first and second central electrodes in a substantially interlaced and symmetrical pattern and forming the boundary electrode symmetrically about the first and second central electrodes, signals generated by charge carriers are substantially of equal strength with respect to both of the central electrodes. The only significant difference in measured signal strength occurs when the charge carriers move to within close proximity of the first central electrode and are received at the first central electrode. The measured signals are then subtracted and compared to quantitatively measure the magnitude of the charge. 10 figs.

  1. A single-run liquid chromatography mass spectrometry method to quantify neuroactive kynurenine pathway metabolites in rat plasma.

    Science.gov (United States)

    Orsatti, Laura; Speziale, Roberto; Orsale, Maria Vittoria; Caretti, Fulvia; Veneziano, Maria; Zini, Matteo; Monteagudo, Edith; Lyons, Kathryn; Beconi, Maria; Chan, Kelvin; Herbst, Todd; Toledo-Sherman, Leticia; Munoz-Sanjuan, Ignacio; Bonelli, Fabio; Dominguez, Celia

    2015-03-25

    Neuroactive metabolites in the kynurenine pathway of tryptophan catabolism are associated with neurodegenerative disorders. Tryptophan is transported across the blood-brain barrier and converted via the kynurenine pathway to N-formyl-L-kynurenine, which is further degraded to L-kynurenine. This metabolite can then generate a group of metabolites called kynurenines, most of which have neuroactive properties. The association of tryptophan catabolic pathway alterations with various central nervous system (CNS) pathologies has raised interest in analytical methods to accurately quantify kynurenines in body fluids. We here describe a rapid and sensitive reverse-phase HPLC-MS/MS method to quantify L-kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxy-L-kynurenine (3HK) and anthranilic acid (AA) in rat plasma. Our goal was to quantify these metabolites in a single run; given their different physico-chemical properties, major efforts were devoted to develop a chromatography suitable for all metabolites that involves plasma protein precipitation with acetonitrile followed by chromatographic separation by C18 RP chromatography, detected by electrospray mass spectrometry. Quantitation range was 0.098-100 ng/ml for 3HK, 9.8-20,000 ng/ml for KYN, 0.49-1000 ng/ml for KYNA and AA. The method was linear (r>0.9963) and validation parameters were within acceptance range (calibration standards and QC accuracy within ±30%). Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming

    DEFF Research Database (Denmark)

    Rauff Lind Christensen, Tue; Klose, Andreas; Andersen, Kim Allan

    important aspects of supplier selection, an important application of the SSFCTP, this does not reflect the real life situation. First, transportation costs faced by many companies are in fact piecewise linear. Secondly, when suppliers offer discounts, either incremental or all-unit discounts, such savings......The Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem (SSFCMCTP) is a problem with versatile applications. This problem is a generalization of the Single-Sink, Fixed-Charge Transportation Problem (SSFCTP), which has a fixed-charge, linear cost structure. However, in at least two...... are neglected in the SSFCTP. The SSFCMCTP overcome this problem by incorporating a staircase cost structure in the cost function instead of the usual one used in SSFCTP. We present a dynamic programming algorithm for the resulting problem. To enhance the performance of the generic algorithm a number...

  3. Three-dimensional charge transport in organic semiconductor single crystals.

    Science.gov (United States)

    He, Tao; Zhang, Xiying; Jia, Jiong; Li, Yexin; Tao, Xutang

    2012-04-24

    Three-dimensional charge transport anisotropy in organic semiconductor single crystals - both plates and rods (above and below, respectively, in the figure) - is measured in well-performing organic field-effect transistors for the first time. The results provide an excellent model for molecular design and device preparation that leads to good performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Plasmonic detection and visualization of directed adsorption of charged single nanoparticles to patterned surfaces

    International Nuclear Information System (INIS)

    Scherbahn, Vitali; Nizamov, Shavkat; Mirsky, Vladimir M.

    2016-01-01

    It has recently been shown that surface plasmon microscopy (SPM) allows single nanoparticles (NPs) on sensor surfaces to be detected and analyzed. The authors have applied this technique to study the adsorption of single metallic and plastic NPs. Binding of gold NPs (40, 60 and 100 nm in size) and of 100 nm polystyrene NPs to gold surfaces modified by differently ω-functionalized alkyl thiols was studied first. Self-assembled monolayers (SAM) with varying terminal functions including amino, carboxy, oligo(ethylene glycol), methyl, or trimethylammonium groups were deposited on gold films to form surfaces possessing different charge and hydrophobicity. The affinity of NPs to these surfaces depends strongly on the type of coating. SAMs terminated with trimethylammonium groups and carboxy group display highly different affinity and therefore were preferred when creating patterned charged surfaces. Citrate-stabilized gold NPs and sulfate-terminated polystyrene NPs were used as negatively charged NPs, while branched polyethylenimine-coated silver NPs were used as positively charged NPs. It is shown that the charged patterned areas on the gold films are capable of selectively adsorbing oppositely charged NPs that can be detected and analyzed with an ∼1 ng⋅mL −1 detection limit. (author)

  5. Emergence of charge density waves and a pseudogap in single-layer TiTe2.

    Science.gov (United States)

    Chen, P; Pai, Woei Wu; Chan, Y-H; Takayama, A; Xu, C-Z; Karn, A; Hasegawa, S; Chou, M Y; Mo, S-K; Fedorov, A-V; Chiang, T-C

    2017-09-11

    Two-dimensional materials constitute a promising platform for developing nanoscale devices and systems. Their physical properties can be very different from those of the corresponding three-dimensional materials because of extreme quantum confinement and dimensional reduction. Here we report a study of TiTe 2 from the single-layer to the bulk limit. Using angle-resolved photoemission spectroscopy and scanning tunneling microscopy and spectroscopy, we observed the emergence of a (2 × 2) charge density wave order in single-layer TiTe 2 with a transition temperature of 92 ± 3 K. Also observed was a pseudogap of about 28 meV at the Fermi level at 4.2 K. Surprisingly, no charge density wave transitions were observed in two-layer and multi-layer TiTe 2 , despite the quasi-two-dimensional nature of the material in the bulk. The unique charge density wave phenomenon in the single layer raises intriguing questions that challenge the prevailing thinking about the mechanisms of charge density wave formation.Due to reduced dimensionality, the properties of 2D materials are often different from their 3D counterparts. Here, the authors identify the emergence of a unique charge density wave (CDW) order in monolayer TiTe 2 that challenges the current understanding of CDW formation.

  6. Solution-grown organic single-crystalline p-n junctions with ambipolar charge transport.

    Science.gov (United States)

    Fan, Congcheng; Zoombelt, Arjan P; Jiang, Hao; Fu, Weifei; Wu, Jiake; Yuan, Wentao; Wang, Yong; Li, Hanying; Chen, Hongzheng; Bao, Zhenan

    2013-10-25

    Organic single-crystalline p-n junctions are grown from mixed solutions. First, C60 crystals (n-type) form and, subsequently, C8-BTBT crystals (p-type) nucleate heterogeneously on the C60 crystals. Both crystals continue to grow simultaneously into single-crystalline p-n junctions that exhibit ambipolar charge transport characteristics. This work provides a platform to study organic single-crystalline p-n junctions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Charge calculation studies done on a single walled carbon nanotube using MOPAC

    Science.gov (United States)

    Negi, S.; Bhartiya, Vivek Kumar; Chaturvedi, S.

    2018-04-01

    Dipole symmetry of induced charges on DWNTs are required for their application as a nanomotor. Earlier a molecular dynamics analysis was performed for a double-walled carbon-nanotube based motor driven by an externally applied sinusoidally varying electric field. One of the ways to get such a system is chemical or end functionalization, which promises to accomplish this specific and rare configuration of the induced charges on the surface of the carbon nanotube (CNT). CNTs are also a promising system for attaching biomolecules for bio-related applications. In an earlier work, ab initio calculations were done to study the electronic and structural properties of the groups -COOH, -OH, -NH2 and -CONH2 functionalized to an (8, 0) SWNT. The systems were shown to have a very stable interaction with the CNTs. The exterior surface of the SWNT is found to be reactive to NH2 (amidogen). In this work, charge calculations are done on a CNT using MOPAC, which is a semi empirical quantum chemistry software package. As a first step, we calculate the effect of NH2 functionalization to a (5,0) SWNT of infinite length. The symmetric charge distribution of the bare SWNT is observed to be disturbed on addition of a single NH2 in the close proximity of the SWNT. A net positive and opposite charge is observed to be induced on the opposite sides of the nanotube circumference, which is, in turn, imperative for the nanomotor applications. The minimum and maximum value of the charge on any atom is observed to increase from - 0.3 to 0.6 and from - 0.3 to - 1.8 electronic charge as compared to the bare SWNT. This fluctuation of the surface charge to larger values than bare CNT, can be attributed to the coulomb repulsion between NH2 and the rest of the charge on the surface which results into minimizing the total energy of the system. No such opposite polarity of charges are observed on adding NH2 to each ring of the SWNT implying addition of a single amidogen to be the most appropriate

  8. Metabolite coupling in genome-scale metabolic networks

    Directory of Open Access Journals (Sweden)

    Palsson Bernhard Ø

    2006-03-01

    Full Text Available Abstract Background Biochemically detailed stoichiometric matrices have now been reconstructed for various bacteria, yeast, and for the human cardiac mitochondrion based on genomic and proteomic data. These networks have been manually curated based on legacy data and elementally and charge balanced. Comparative analysis of these well curated networks is now possible. Pairs of metabolites often appear together in several network reactions, linking them topologically. This co-occurrence of pairs of metabolites in metabolic reactions is termed herein "metabolite coupling." These metabolite pairs can be directly computed from the stoichiometric matrix, S. Metabolite coupling is derived from the matrix ŜŜT, whose off-diagonal elements indicate the number of reactions in which any two metabolites participate together, where Ŝ is the binary form of S. Results Metabolite coupling in the studied networks was found to be dominated by a relatively small group of highly interacting pairs of metabolites. As would be expected, metabolites with high individual metabolite connectivity also tended to be those with the highest metabolite coupling, as the most connected metabolites couple more often. For metabolite pairs that are not highly coupled, we show that the number of reactions a pair of metabolites shares across a metabolic network closely approximates a line on a log-log scale. We also show that the preferential coupling of two metabolites with each other is spread across the spectrum of metabolites and is not unique to the most connected metabolites. We provide a measure for determining which metabolite pairs couple more often than would be expected based on their individual connectivity in the network and show that these metabolites often derive their principal biological functions from existing in pairs. Thus, analysis of metabolite coupling provides information beyond that which is found from studying the individual connectivity of individual

  9. Reorganization energy upon charging a single molecule on an insulator measured by atomic force microscopy

    Science.gov (United States)

    Fatayer, Shadi; Schuler, Bruno; Steurer, Wolfram; Scivetti, Ivan; Repp, Jascha; Gross, Leo; Persson, Mats; Meyer, Gerhard

    2018-05-01

    Intermolecular single-electron transfer on electrically insulating films is a key process in molecular electronics1-4 and an important example of a redox reaction5,6. Electron-transfer rates in molecular systems depend on a few fundamental parameters, such as interadsorbate distance, temperature and, in particular, the Marcus reorganization energy7. This crucial parameter is the energy gain that results from the distortion of the equilibrium nuclear geometry in the molecule and its environment on charging8,9. The substrate, especially ionic films10, can have an important influence on the reorganization energy11,12. Reorganization energies are measured in electrochemistry13 as well as with optical14,15 and photoemission spectroscopies16,17, but not at the single-molecule limit and nor on insulating surfaces. Atomic force microscopy (AFM), with single-charge sensitivity18-22, atomic-scale spatial resolution20 and operable on insulating films, overcomes these challenges. Here, we investigate redox reactions of single naphthalocyanine (NPc) molecules on multilayered NaCl films. Employing the atomic force microscope as an ultralow current meter allows us to measure the differential conductance related to transitions between two charge states in both directions. Thereby, the reorganization energy of NPc on NaCl is determined as (0.8 ± 0.2) eV, and density functional theory (DFT) calculations provide the atomistic picture of the nuclear relaxations on charging. Our approach presents a route to perform tunnelling spectroscopy of single adsorbates on insulating substrates and provides insight into single-electron intermolecular transport.

  10. Surface structure modification of single crystal graphite after slow, highly charged ion irradiation

    Science.gov (United States)

    Alzaher, I.; Akcöltekin, S.; Ban-d'Etat, B.; Manil, B.; Dey, K. R.; Been, T.; Boduch, P.; Rothard, H.; Schleberger, M.; Lebius, H.

    2018-04-01

    Single crystal graphite was irradiated by slow, highly charged ions. The modification of the surface structure was studied by means of Low-Energy Electron Diffraction. The observed damage cross section increases with the potential energy, i.e. the charge state of the incident ion, at a constant kinetic energy. The potential energy is more efficient for the damage production than the kinetic energy by more than a factor of twenty. Comparison with earlier results hints to a strong link between early electron creation and later target atom rearrangement. With increasing ion fluence, the initially large-scale single crystal is first transformed into μ m-sized crystals, before complete amorphisation takes place.

  11. Impact of charge carrier injection on single-chain photophysics of conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Felix J.; Vogelsang, Jan, E-mail: jan.vogelsang@physik.uni-regensburg.de; Lupton, John M. [Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany)

    2016-06-27

    Charges in conjugated polymer materials have a strong impact on the photophysics and their interaction with the primary excited state species has to be taken into account in understanding device properties. Here, we employ single-molecule spectroscopy to unravel the influence of charges on several photoluminescence (PL) observables. The charges are injected either stochastically by a photochemical process or deterministically in a hole-injection sandwich device configuration. We find that upon charge injection, besides a blue-shift of the PL emission and a shortening of the PL lifetime due to quenching and blocking of the lowest-energy chromophores, the non-classical photon arrival time distribution of the multichromophoric chain is modified towards a more classical distribution. Surprisingly, the fidelity of photon antibunching deteriorates upon charging, whereas one would actually expect the opposite: the number of chromophores to be reduced. A qualitative model is presented to explain the observed PL changes. The results are of interest to developing a microscopic understanding of the intrinsic charge-exciton quenching interaction in devices.

  12. Investigation of charge multiplication in single crystalline CVD diamond particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Muškinja, M.; Cindro, V.; Gorišek, A. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Kagan, H. [Department of Physics, Ohio State University (United States); Kramberger, G., E-mail: Gregor.Kramberger@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Mandić, I. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Mikuž, M. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Faculty of Physics and Mathematics, University of Ljubljana (Slovenia); Phan, S.; Smith, D.S. [Department of Physics, Ohio State University (United States); Zavrtanik, M. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2017-01-01

    A special metallization pattern was created on a single crystalline diamond detector aimed at creating high enough electric field for impact ionization in the detector material. Electric field line focusing through electrode design and very high bias voltages were used to obtain high electric fields. Previous measurements and theoretical calculations indicated that drifting charge multiplication by impact ionization could take place. A large increase of induced charge was observed for the smallest dot electrode which points to charge multiplication while for the large dot and pad detector structure no such effect was observed. The evolution of induced currents was also monitored with the transient current technique. Induced current pulses with duration of order 1 μs were measured. The multiplication gain was found to depend on the particle rate.

  13. Analysis of Metabolites in Stem Parasitic Plant Interactions: Interaction of Cuscuta–Momordica versus Cassytha–Ipomoea

    Science.gov (United States)

    Furuhashi, Takeshi; Nakamura, Takemichi; Iwase, Koji

    2016-01-01

    Cuscuta and Cassytha are two well-known stem parasitic plant genera with reduced leaves and roots, inducing haustoria in their stems. Their similar appearance in the field has been recognized, but few comparative studies on their respective plant interactions are available. To compare their interactions, we conducted a metabolite analysis of both the Cassytha–Ipomoea and the Cuscuta–Momordica interaction. We investigated the energy charge of the metabolites by UFLC (ultra-high performance liquid chromatography), and conducted GC-MS (gas chromatography-mass spectrometry) analysis for polar metabolites (e.g., saccharides, polyols) and steroids. The energy charge after parasitization changed considerably in Cassytha but not in Cusucta. Cuscuta changed its steroid pattern during the plant interaction, whereas Cassytha did not. In the polar metabolite analysis, the laminaribiose increase after parasitization was conspicuous in Cuscuta, but not in Cassytha. This metabolite profile difference points to different lifestyles and parasitic strategies. PMID:27941603

  14. Analysis of Metabolites in Stem Parasitic Plant Interactions: Interaction of Cuscuta–Momordica versus Cassytha–Ipomoea

    Directory of Open Access Journals (Sweden)

    Takeshi Furuhashi

    2016-12-01

    Full Text Available Cuscuta and Cassytha are two well-known stem parasitic plant genera with reduced leaves and roots, inducing haustoria in their stems. Their similar appearance in the field has been recognized, but few comparative studies on their respective plant interactions are available. To compare their interactions, we conducted a metabolite analysis of both the Cassytha–Ipomoea and the Cuscuta–Momordica interaction. We investigated the energy charge of the metabolites by UFLC (ultra-high performance liquid chromatography, and conducted GC-MS (gas chromatography-mass spectrometry analysis for polar metabolites (e.g., saccharides, polyols and steroids. The energy charge after parasitization changed considerably in Cassytha but not in Cusucta. Cuscuta changed its steroid pattern during the plant interaction, whereas Cassytha did not. In the polar metabolite analysis, the laminaribiose increase after parasitization was conspicuous in Cuscuta, but not in Cassytha. This metabolite profile difference points to different lifestyles and parasitic strategies.

  15. Analysis of Metabolites in Stem Parasitic Plant Interactions: Interaction of Cuscuta-Momordica versus Cassytha-Ipomoea.

    Science.gov (United States)

    Furuhashi, Takeshi; Nakamura, Takemichi; Iwase, Koji

    2016-12-07

    Cuscuta and Cassytha are two well-known stem parasitic plant genera with reduced leaves and roots, inducing haustoria in their stems. Their similar appearance in the field has been recognized, but few comparative studies on their respective plant interactions are available. To compare their interactions, we conducted a metabolite analysis of both the Cassytha-Ipomoea and the Cuscuta-Momordica interaction. We investigated the energy charge of the metabolites by UFLC (ultra-high performance liquid chromatography), and conducted GC-MS (gas chromatography-mass spectrometry) analysis for polar metabolites (e.g., saccharides, polyols) and steroids. The energy charge after parasitization changed considerably in Cassytha but not in Cusucta . Cuscuta changed its steroid pattern during the plant interaction, whereas Cassytha did not. In the polar metabolite analysis, the laminaribiose increase after parasitization was conspicuous in Cuscuta , but not in Cassytha . This metabolite profile difference points to different lifestyles and parasitic strategies.

  16. Single-Cell Mass Spectrometry Reveals Changes in Lipid and Metabolite Expression in RAW 264.7 Cells upon Lipopolysaccharide Stimulation

    Science.gov (United States)

    Yang, Bo; Patterson, Nathan Heath; Tsui, Tina; Caprioli, Richard M.; Norris, Jeremy L.

    2018-05-01

    It has been widely recognized that individual cells that exist within a large population of cells, even if they are genetically identical, can have divergent molecular makeups resulting from a variety of factors, including local environmental factors and stochastic processes within each cell. Presently, numerous approaches have been described that permit the resolution of these single-cell expression differences for RNA and protein; however, relatively few techniques exist for the study of lipids and metabolites in this manner. This study presents a methodology for the analysis of metabolite and lipid expression at the level of a single cell through the use of imaging mass spectrometry on a high-performance Fourier transform ion cyclotron resonance mass spectrometer. This report provides a detailed description of the overall experimental approach, including sample preparation as well as the data acquisition and analysis strategy for single cells. Applying this approach to the study of cultured RAW264.7 cells, we demonstrate that this method can be used to study the variation in molecular expression with cell populations and is sensitive to alterations in that expression that occurs upon lipopolysaccharide stimulation. [Figure not available: see fulltext.

  17. Single-Cell Mass Spectrometry Reveals Changes in Lipid and Metabolite Expression in RAW 264.7 Cells upon Lipopolysaccharide Stimulation

    Science.gov (United States)

    Yang, Bo; Patterson, Nathan Heath; Tsui, Tina; Caprioli, Richard M.; Norris, Jeremy L.

    2018-03-01

    It has been widely recognized that individual cells that exist within a large population of cells, even if they are genetically identical, can have divergent molecular makeups resulting from a variety of factors, including local environmental factors and stochastic processes within each cell. Presently, numerous approaches have been described that permit the resolution of these single-cell expression differences for RNA and protein; however, relatively few techniques exist for the study of lipids and metabolites in this manner. This study presents a methodology for the analysis of metabolite and lipid expression at the level of a single cell through the use of imaging mass spectrometry on a high-performance Fourier transform ion cyclotron resonance mass spectrometer. This report provides a detailed description of the overall experimental approach, including sample preparation as well as the data acquisition and analysis strategy for single cells. Applying this approach to the study of cultured RAW264.7 cells, we demonstrate that this method can be used to study the variation in molecular expression with cell populations and is sensitive to alterations in that expression that occurs upon lipopolysaccharide stimulation. [Figure not available: see fulltext.

  18. Quasi-free pion single charge exchange

    International Nuclear Information System (INIS)

    Ouyang, J.

    1992-12-01

    Cross sections for the quasi-free (QF) region for pion single charge exchange (SCX) were measured with beams of 475 MeV π - , 500 MeV π ± , and 400 MeV π - , with most data at 500 MeV π ± . The LAMPF π 0 spectrometer and a proton detector arm were placed on each side of the beam with different scattering angles. Up to twelve targets, from hydrogen to bismuth, were used. Both inclusive and coincidence measurements were performed. The extraction of peak shape and cross section for the QF peak, the effective number of nucleons involved in the reaction, mass dependence, and angular dependence were studied for the inclusive measurement. Calculations with the local random phase approximation (RPA) were used to understand the inclusive experimental results. A collection of experimental results is given for both inclusive and coincidence measurements

  19. Charging of Single Micron Sized Dust Grains by Secondary Electron Emission: A Laboratory Study

    Science.gov (United States)

    Spann, James F., Jr.; Venturini, Catherine C.; Comfort, R. H.

    1998-01-01

    We present the details of a new laboratory study whose objective is to experimentally study the interaction of micron sized particles with plasmas and electromagnetic radiation. Specifically, to investigate under what conditions and to what extent do particles of various compositions and sizes become charged, or discharged, while exposed to an electron beam and ultraviolet radiation environment The emphasis is the study of the two charging mechanisms, secondary emission of electrons and photoelectric effect. The experiment uses a technique known as electrodynamic suspension of particles. With this technique, a single charged particle is electrodynamically levitated and then exposed to a controlled environment. Its charge to mass ratio is directly measured. Viscous drag measurements and the light scattering measurements characterize its size and optical characteristics. The environment to which the particle is expose may consist of room temperature and pressure or a rarefied atmosphere where only one major gaseous constituent is present, or, as in this case, a vacuum environment under electron bombardment or UV radiation . In addition, the environment can be cycled as part of the experiment. Therefore, using this technique, a single particle can be repeatedly exposed to a controlled environment and its response measured, or a single particle can be exposed to similar environments with minor differences and its response measured as a function of only the changed environmental conditions.

  20. Engineering Microbial Metabolite Dynamics and Heterogeneity.

    Science.gov (United States)

    Schmitz, Alexander C; Hartline, Christopher J; Zhang, Fuzhong

    2017-10-01

    As yields for biological chemical production in microorganisms approach their theoretical maximum, metabolic engineering requires new tools, and approaches for improvements beyond what traditional strategies can achieve. Engineering metabolite dynamics and metabolite heterogeneity is necessary to achieve further improvements in product titers, productivities, and yields. Metabolite dynamics, the ensemble change in metabolite concentration over time, arise from the need for microbes to adapt their metabolism in response to the extracellular environment and are important for controlling growth and productivity in industrial fermentations. Metabolite heterogeneity, the cell-to-cell variation in a metabolite concentration in an isoclonal population, has a significant impact on ensemble productivity. Recent advances in single cell analysis enable a more complete understanding of the processes driving metabolite heterogeneity and reveal metabolic engineering targets. The authors present an overview of the mechanistic origins of metabolite dynamics and heterogeneity, why they are important, their potential effects in chemical production processes, and tools and strategies for engineering metabolite dynamics and heterogeneity. The authors emphasize that the ability to control metabolite dynamics and heterogeneity will bring new avenues of engineering to increase productivity of microbial strains. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Single-event phenomena on recent semiconductor devices. Charge-type multiple-bit upsets in high integrated memories

    International Nuclear Information System (INIS)

    Makihara, Akiko; Shindou, Hiroyuki; Nemoto, Norio; Kuboyama, Satoshi; Matsuda, Sumio; Ohshima, Takeshi; Hirao, Toshio; Itoh, Hisayoshi

    2001-01-01

    High integrated memories are used in solid state data recorder (SSDR) of the satellite for accumulating observation data. Single event upset phenomena which turn over an accumulated data in the memory cells are caused by heavy ion incidence. Studies on single-bit upset and multiple-bit upset phenomena in the high integrated memory cells are in progress recently. 16 Mbit DRAM (Dynamic Random Access Memories) and 64 Mbit DRAM are irradiated by heavy ion species, such as iodine, bromine and nickel, in comparison with the irradiation damage in the cosmic environment. Data written on the memory devices are read out after the irradiation. The memory cells in three kinds of states, all of charged state, all of discharged state, and an alternative state of charge and discharge, are irradiated for sorting out error modes caused by heavy ion incidence. The soft error in a single memory cells is known as a turn over from charged state to discharged state. Electrons in electron-hole pair generated by heavy ion incidence are captured in a diffusion region between capacitor electrodes of semiconductor. The charged states in the capacitor electrodes before the irradiation are neutralized and changed to the discharged states. According to high integration of the memories, many of the cells are affected by a single ion incidence. The multiple-bit upsets, however, are generated in the memory cells of discharged state before the irradiation, also. The charge-type multiple-bit upsets is considered as that error data are written on the DRAM during refresh cycle of a sense-up circuit and a pre-charge circuit which control the DRAM. (M. Suetake)

  2. Interaction of singly and multiply charged ions with a lithium-fluoride surface

    International Nuclear Information System (INIS)

    Wirtz, L.

    2001-10-01

    Charge transfer between slow ions and an ionic crystal surface still poses a considerable challenge to theory due to the intrinsic many-body character of the system. For the neutralization of multiply charged ions in front of metal surfaces, the Classical Over the Barrier (COB) model is a widely used tool. We present an extension of this model to ionic crystal surfaces where the localization of valence electrons at the anion sites and the lack of cylindrical symmetry of the ion-surface system impede a simple analytical estimate of electron transfer rates. We use a classical trajectory Monte Carlo approach to calculate electron transfer rates for different charge states of the projectile ion. With these rates we perform a Monte Carlo simulation of the neutralization of slow Ne10+ ions in vertical incidence on an LiF surface. Capture of one or several electrons may lead to a local positive charge up of the surface. The projectile dynamics depends on the balance between the repulsion due to this charge and the attraction due to the self-image potential. In a simulation that treats electronic and nuclear dynamics simultaneously, we show that the image attraction dominates over the repulsive force. Backscattering of very slow multiply charged projectiles high above the surface without touching it ('trampoline effect') does not take place. Instead, the projectile ion penetrates into the surface or is reflected due to close binary collision with surface ions. The case of a singly charged ion in front of an LiF surface is within the reach of ab-initio calculations. We use a multi-configuration self consistent field (MCSCF) and a multi-reference configuration interaction (MR-CI) method to calculate adiabatic potential energy curves for a system consisting of the projectile ion and an embedded cluster of surface ions. With increasing cluster size, the energy levels of the embedded cluster converge towards the band structure of the infinitely extended solid. Due to

  3. Unbiased, complete solar charging of a neutral flow battery by a single Si photocathode

    DEFF Research Database (Denmark)

    Wedege, Kristina; Bae, Dowon; Dražević, Emil

    2018-01-01

    Solar redox flow batteries have attracted attention as a possible integrated technology for simultaneous conversion and storage of solar energy. In this work, we review current efforts to design aqueous solar flow batteries in terms of battery electrolyte capacity, solar conversion efficiency...... and depth of solar charge. From a materials cost and design perspective, a simple, cost-efficient, aqueous solar redox flow battery will most likely incorporate only one semiconductor, and we demonstrate here a system where a single photocathode is accurately matched to the redox couples to allow...... for a complete solar charge. The single TiO2 protected Si photocathode with a catalytic Pt layer can fully solar charge a neutral TEMPO-sulfate/ferricyanide battery with a cell voltage of 0.35 V. An unbiased solar conversion efficiency of 1.6% is obtained and this system represents a new strategy in solar RFBs...

  4. Pharmacokinetics of lansoprazole and its main metabolites after single and multiple intravenous doses in healthy Chinese subjects.

    Science.gov (United States)

    Zhang, Dan; Zhang, Yanan; Liu, Man; Wang, Xiaolin; Yang, Man; Han, Jing; Liu, Huichen

    2013-09-01

    The aim of the study was to evaluate and compare the pharmacokinetics of lansoprazole (LPZ) and its main metabolites, 5'-hydroxy lansoprazole (HLPZ) and lansoprazole sulfone (LPZS), after single and multiple intravenous (i.v.) doses of LPZ in healthy Chinese subjects. Twelve subjects (six males and six females) were given a single dose of LPZ by i.v. infusion on day 1, and multiple doses from day 2 to day 6. Blood samples were collected at designated time points for analysis of plasma concentrations of LPZ, HLPZ and LPZS by an LC-MS/MS method. LPZ was generally well tolerated in healthy Chinese subjects. After single and multiple i.v. doses of 30 mg LPZ, the C max values of LPZ, HLPZ and LPZS were 1490 ± 290 and 1450 ± 280, 175 ± 71 and 154 ± 56, and 51.3 ± 82.9 and 74.1 ± 158.7 ng/mL, with the AUC0-t values 3280 ± 2550 and 4260 ± 3880, 381 ± 128 and 389 ± 111, and 389 ± 1204 and 700 ± 2255 ng h/mL, respectively. The t 1/2 and CL values of LPZ after single and multiple i.v. doses were 1.48 ± 1.03 and 2.19 ± 1.03 h, and 11.67 ± 4.49 and 9.56 ± 4.08 L/h, respectively. Compared with the pharmacokinetics of LPZ after a single dose, t 1/2 increased markedly, CL decreased significantly and AUC increased by over 20 % after multiple doses. The results indicated that there was drug accumulation of LPZ after multiple i.v. doses, and there was no gender-related difference in pharmacokinetics of LPZ and its two metabolites.

  5. Stark tuning and electrical charge state control of single divacancies in silicon carbide

    Science.gov (United States)

    de las Casas, Charles F.; Christle, David J.; Ul Hassan, Jawad; Ohshima, Takeshi; Son, Nguyen T.; Awschalom, David D.

    2017-12-01

    Neutrally charged divacancies in silicon carbide (SiC) are paramagnetic color centers whose long coherence times and near-telecom operating wavelengths make them promising for scalable quantum communication technologies compatible with existing fiber optic networks. However, local strain inhomogeneity can randomly perturb their optical transition frequencies, which degrades the indistinguishability of photons emitted from separate defects and hinders their coupling to optical cavities. Here, we show that electric fields can be used to tune the optical transition frequencies of single neutral divacancy defects in 4H-SiC over a range of several GHz via the DC Stark effect. The same technique can also control the charge state of the defect on microsecond timescales, which we use to stabilize unstable or non-neutral divacancies into their neutral charge state. Using fluorescence-based charge state detection, we show that both 975 nm and 1130 nm excitation can prepare their neutral charge state with near unity efficiency.

  6. Electronic transport in single-helical protein molecules: Effects of multiple charge conduction pathways and helical symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Sourav, E-mail: sourav.kunduphy@gmail.com; Karmakar, S.N.

    2016-07-15

    We propose a tight-binding model to investigate electronic transport properties of single helical protein molecules incorporating both the helical symmetry and the possibility of multiple charge transfer pathways. Our study reveals that due to existence of both the multiple charge transfer pathways and helical symmetry, the transport properties are quite rigid under influence of environmental fluctuations which indicates that these biomolecules can serve as better alternatives in nanoelectronic devices than its other biological counterparts e.g., single-stranded DNA.

  7. Optimized Charging Scheduling with Single Mobile Charger for Wireless Rechargeable Sensor Networks

    Directory of Open Access Journals (Sweden)

    Qihua Wang

    2017-11-01

    Full Text Available Due to the rapid development of wireless charging technology, the recharging issue in wireless rechargeable sensor network (WRSN has been a popular research problem in the past few years. The weakness of previous work is that charging route planning is not reasonable. In this work, a dynamic optimal scheduling scheme aiming to maximize the vacation time ratio of a single mobile changer for WRSN is proposed. In the proposed scheme, the wireless sensor network is divided into several sub-networks according to the initial topology of deployed sensor networks. After comprehensive analysis of energy states, working state and constraints for different sensor nodes in WRSN, we transform the optimized charging path problem of the whole network into the local optimization problem of the sub networks. The optimized charging path with respect to dynamic network topology in each sub-network is obtained by solving an optimization problem, and the lifetime of the deployed wireless sensor network can be prolonged. Simulation results show that the proposed scheme has good and reliable performance for a small wireless rechargeable sensor network.

  8. Single Molecule Spectroelectrochemistry of Interfacial Charge Transfer Dynamics In Hybrid Organic Solar Cell

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Shanlin [Univ. of Alabama, Tuscaloosa, AL (United States)

    2014-11-16

    Our research under support of this DOE grant is focused on applied and fundamental aspects of model organic solar cell systems. Major accomplishments are: 1) we developed a spectroelectorchemistry technique of single molecule single nanoparticle method to study charge transfer between conjugated polymers and semiconductor at the single molecule level. The fluorescence of individual fluorescent polymers at semiconductor surfaces was shown to exhibit blinking behavior compared to molecules on glass substrates. Single molecule fluorescence excitation anisotropy measurements showed the conformation of the polymer molecules did not differ appreciably between glass and semiconductor substrates. The similarities in molecular conformation suggest that the observed differences in blinking activity are due to charge transfer between fluorescent polymer and semiconductor, which provides additional pathways between states of high and low fluorescence quantum efficiency. Similar spectroelectrochemistry work has been done for small organic dyes for understand their charge transfer dynamics on various substrates and electrochemical environments; 2) We developed a method of transferring semiconductor nanoparticles (NPs) and graphene oxide (GO) nanosheets into organic solvent for a potential electron acceptor in bulk heterojunction organic solar cells which employed polymer semiconductor as the electron donor. Electron transfer from the polymer semiconductor to semiconductor and GO in solutions and thin films was established through fluorescence spectroscopy and electroluminescence measurements. Solar cells containing these materials were constructed and evaluated using transient absorption spectroscopy and dynamic fluorescence techniques to understand the charge carrier generation and recombination events; 3) We invented a spectroelectorchemistry technique using light scattering and electroluminescence for rapid size determination and studying electrochemistry of single NPs in an

  9. Features of produced flows of multiply charged ions at interaction of laser radiation with single-component solids

    International Nuclear Information System (INIS)

    Bedilov, M.R.; Bedilov, R.M.; Beysembaeva, H.B.; Sabitov, M.S.; Kamalova, J.O.

    2006-01-01

    Full text: The results of study features of formation multiply charged ions spectra of single-component solids depending on a target element composition in an interval of laser radiation power density q = 10 7 / 10 12 W/cm 2 with using of the laser multiply charged mass spectrometer [1] are given in this work. As single-component targets are used Be, B, C, Al, Ti, Fe, Co, Ni, Cu, Ag, Ta, W, Pt, Au as tablets in diameter of 10 mm and thickness of 3-5 mm. Analysis of the obtained mass-charge and energy spectra of multiply charged ions depending on a target element composition has allowed us to find features of formation spectra and escape multiply charged ions of a single-component targets. These features consist in characteristic changes: a threshold produced of ions; formation of mass-charge and energy spectra of multiply charged ions; nonlinear dependence of maximal charge number (Z max ) of ions from power density (q) of the laser; etc. Experimentally it was found that, with target atomic weight increase, threshold power of ions occurrence, nonlinearity ionization target structure, and intensity of ions, and energy spectra of ions increase. Let's note that, in case of targets Be, B, C, Al by laser radiation it is completely ionized and multiply charged ions and nuclei Be 4+ , B 5+ , C 6+ , Al 13+ are formed. The major level of ionization is attained in case of targets from Ti (Ti 17+ ) and Co (Co 18+ ). It is peculiar that structure formation and escape of multiply charged ion flows with Z max and nuclei depending on target element composition corresponds to various maximal values q of the laser. Increase of the maximal charge number of ions (atoms) observed with increase q of the laser for all investigated targets has nonlinear dependence in various levels that is especially shown beginning from q≥ 10 11 W/cm 2 . It is found that depending on target element composition multiply charged ions have a wide energy range with a maximum of allocation. With increase

  10. Ejecta from single-charge cratering explosions

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, R H

    1970-05-15

    The objective was to obtain experimental data tracing the location of ejecta to its origin within the crater region. The experiment included ten high-explosive spherical charges weighing from 8 to 1000 pounds and detonated in a playa dry lake soil on the Tonopah Test Range. Each event included from 24 to 40 locations of distinctly different tracer material embedded in a plane in the expected crater region. Tracers consisted of glass, ceramic and bugle beads, chopped metal, and plastic wire. Results of this experiment yielded data on tracer dispersion as a function of charge weight, charge burial depth and tracer emplacement position. Tracer pattern parameters such as center-of-tracer mass, range to center-of-tracer mass, and angle to center-of-tracer mass were determined. There is a clear tendency for range (to center-of-tracer mass) and the size of the dispersion pattern to decrease as tracer emplacement depth increases. Increasing tracer emplacement depth and range tends to decrease the area over which tracers are dispersed on the ground surface. Tracers at the same scaled position relative to the charge were deposited closer to the crater (on a scaled basis) as charge weight was increased. (author)

  11. Observation and applications of single-electron charge signals in the XENON100 experiment

    NARCIS (Netherlands)

    Aprile, E.; et al., [Unknown; Alfonsi, M.; Colijn, A.P.; Decowski, M.P.

    2014-01-01

    The XENON100 dark matter experiment uses liquid xenon in a time projection chamber (TPC) to measure xenon nuclear recoils resulting from the scattering of dark matter weakly interacting massive particles (WIMPs). In this paper, we report the observation of single-electron charge signals which are

  12. Single-Bunch Stability With Direct Space Charge

    CERN Multimedia

    Oeftiger, Adrian

    2017-01-01

    Previous studies have shown the suppressing effect of direct space charge on impedance-driven head-tail instabilities. The present work investigates transverse stability for the HL-LHC scenario based on our macro-particle simulation tool PyHEADTAIL using realistic bunch distributions. The impact of selfconsistent modelling is briefly discussed for non-linear space charge forces. We study how space charge pushes the instability threshold for the transverse mode coupling instability (TMCI) occurring between mode 0 and -1. Next we consider finite chromaticity: in absence of space charge, the impedance model predicts head-tail instabilities. For a selected case below TMCI threshold at Q0 = 5, we demonstrate the stabilising effect of space charge. Finally, we compare simulation results to past LHC measurements.

  13. Spiro-OMeTAD single crystals: Remarkably enhanced charge-carrier transport via mesoscale ordering

    KAUST Repository

    Shi, Dong

    2016-04-15

    We report the crystal structure and hole-transport mechanism in spiro-OMeTAD [2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene], the dominant hole-transporting material in perovskite and solid-state dye-sensitized solar cells. Despite spiro-OMeTAD’s paramount role in such devices, its crystal structure was unknown because of highly disordered solution-processed films; the hole-transport pathways remained ill-defined and the charge carrier mobilities were low, posing a major bottleneck for advancing cell efficiencies. We devised an antisolvent crystallization strategy to grow single crystals of spiro-OMeTAD, which allowed us to experimentally elucidate its molecular packing and transport properties. Electronic structure calculations enabled us to map spiro-OMeTAD’s intermolecular charge-hopping pathways. Promisingly, single-crystal mobilities were found to exceed their thin-film counterparts by three orders of magnitude. Our findings underscore mesoscale ordering as a key strategy to achieving breakthroughs in hole-transport material engineering of solar cells.

  14. Persistent Charge-Density-Wave Order in Single-Layer TaSe2.

    Science.gov (United States)

    Ryu, Hyejin; Chen, Yi; Kim, Heejung; Tsai, Hsin-Zon; Tang, Shujie; Jiang, Juan; Liou, Franklin; Kahn, Salman; Jia, Caihong; Omrani, Arash A; Shim, Ji Hoon; Hussain, Zahid; Shen, Zhi-Xun; Kim, Kyoo; Min, Byung Il; Hwang, Choongyu; Crommie, Michael F; Mo, Sung-Kwan

    2018-02-14

    We present the electronic characterization of single-layer 1H-TaSe 2 grown by molecular beam epitaxy using a combined angle-resolved photoemission spectroscopy, scanning tunneling microscopy/spectroscopy, and density functional theory calculations. We demonstrate that 3 × 3 charge-density-wave (CDW) order persists despite distinct changes in the low energy electronic structure highlighted by the reduction in the number of bands crossing the Fermi energy and the corresponding modification of Fermi surface topology. Enhanced spin-orbit coupling and lattice distortion in the single-layer play a crucial role in the formation of CDW order. Our findings provide a deeper understanding of the nature of CDW order in the two-dimensional limit.

  15. Superconducting single electron transistor for charge sensing in Si/SiGe-based quantum dots

    Science.gov (United States)

    Yang, Zhen

    Si-based quantum devices, including Si/SiGe quantum dots (QD), are promising candidates for spin-based quantum bits (quits), which are a potential platform for quantum information processing. Meanwhile, qubit readout remains a challenging task related to semiconductor-based quantum computation. This thesis describes two readout devices for Si/SiGe QDs and the techniques for developing them from a traditional single electron transistor (SET). By embedding an SET in a tank circuit and operating it in the radio-frequency (RF) regime, a superconducting RF-SET has quick response as well as ultra high charge sensitivity and can be an excellent charge sensor for the QDs. We demonstrate such RF-SETs for QDs in a Si/SiGe heterostructure. Characterization of the SET in magnetic fields is studied for future exploration of advanced techniques such as spin detection and spin state manipulation. By replacing the tank circuit with a high-quality-factor microwave cavity, the embedded SET will be operated in the supercurrent regime as a single Cooper pair transistor (CPT) to further increase the charge sensitivity and reduce any dissipation. The operating principle and implementation of the cavity-embedded CPT (cCPT) will be introduced.

  16. Emerging New Strategies for Successful Metabolite Identification in Metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Bingol, Ahmet K.; Bruschweiler-Li, Lei; Li, Dawei; Zhang, Bo; Xie, Mouzhe; Bruschweiler, Rafael

    2016-02-26

    NMR is a very powerful tool for the identification of known and unknown (or unnamed) metabolites in complex mixtures as encountered in metabolomics. Known compounds can be reliably identified using 2D NMR methods, such as 13C-1H HSQC, for which powerful web servers with databases are available for semi-automated analysis. For the identification of unknown compounds, new combinations of NMR with MS have been developed recently that make synergistic use of the mutual strengths of the two techniques. The use of chemical additives to the NMR tube, such as reactive agents, paramagnetic ions, or charged silica nanoparticles, permit the identification of metabolites with specific physical chemical properties. In the following sections, we give an overview of some of the recent advances in metabolite identification and discuss remaining challenges.

  17. Testing multistage gain and offset trimming in a single photon counting IC with a charge sharing elimination algorithm

    International Nuclear Information System (INIS)

    Krzyżanowska, A.; Gryboś, P.; Szczygieł, R.; Maj, P.

    2015-01-01

    Designing a hybrid pixel detector readout electronics operating in a single photon counting mode is a very challenging process, where many main parameters are optimized in parallel (e.g. gain, noise, and threshold dispersion). Additional requirements for a smaller pixel size with extended functionality push designers to use new deep sub-micron technologies. Minimizing the channel size is possible, however, with a decreased pixel size, the charge sharing effect becomes a more important issue. To overcome this problem, we designed an integrated circuit prototype produced in CMOS 40 nm technology, which has an extended functionality of a single pixel. A C8P1 algorithm for the charge sharing effect compensation was implemented. In the algorithm's first stage the charge is rebuilt in a signal rebuilt hub fed by the CSA (charge sensitive amplifier) outputs from four neighbouring pixels. Then, the pixel with the biggest amount of charge is chosen, after a comparison with all the adjacent ones. In order to process the data in such a complicated way, a certain architecture of a single channel was proposed, which allows for: ⋅ processing the signal with the possibility of total charge reconstruction (by connecting with the adjacent pixels), ⋅ a comparison of certain pixel amplitude to its 8 neighbours, ⋅ the extended testability of each block inside the channel to measure CSA gain dispersion, shaper gain dispersion, threshold dispersion (including the simultaneous generation of different pulse amplitudes from different pixels), ⋅ trimming all the necessary blocks for proper operation. We present a solution for multistage gain and offset trimming implemented in the IC prototype. It allows for minimization of the total charge extraction errors, minimization of threshold dispersion in the pixel matrix and minimization of errors of comparison of certain pixel pulse amplitudes with all its neighbours. The detailed architecture of a single channel is presented

  18. Inclusive photoproduction of single charged particles at high pT

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Flower, P.S.; Hallewell, G.; Morris, J.A.G.; Morris, J.V.; Paterson, C.N.; Sharp, P.H.; Atkinson, M.; Brook, N.; Coyle, P.; Dickinson, B.; Donnachie, A.; Doyle, A.T.; Ellison, R.J.; Foster, J.M.; Hughes-Jones, R.E.; Ibbotson, M.; Kolya, S.D.; Lafferty, G.D.; McCann, H.; McManus, C.; Mercer, D.; Ottewell, P.J.; Reid, D.; Thompson, R.J.; Waterhouse, J.; Barberis, D.; Davenport, M.; Eades, J.; McClatchey, R.; Brodbeck, T.J.; Charity, T.; Clegg, A.B.; Henderson, R.C.W.; Hickman, M.T.; Keemer, N.R.; Newton, D.; O'Connor, A.; Wilson, G.W.; Danaher, S.; Galbraith, W.; Thacker, N.A.; Thompson, L.

    1989-01-01

    Single charged-particle inclusive cross sections for photon, pion and kaon beams on hydrogen at the CERN-SPS are presented as functions of p T and x F . Data cover the range 0.0 T F T < 1.6 GeV/c for the photon-induced data. Using the hadron-induced data to estimate the hadronic behaviour of the photon, the difference distributions and ratios of cross sections are a measure of the contribution of the point-like photon interactions. The data are compared with QCD calculations and show broadly similar features. (orig.)

  19. Charge Enhancement of Single-Stranded DNA in Negative Electrospray Ionization Using the Supercharging Reagent Meta-nitrobenzyl Alcohol

    Science.gov (United States)

    Brahim, Bessem; Alves, Sandra; Cole, Richard B.; Tabet, Jean-Claude

    2013-12-01

    Charge enhancement of single-stranded oligonucleotide ions in negative ESI mode is investigated. The employed reagent, meta-nitrobenzyl alcohol (m-NBA), was found to improve total signal intensity (Itot), increase the highest observed charge states (zhigh), and raise the average charge states (zavg) of all tested oligonucleotides analyzed in negative ESI. To quantify these increases, signal enhancement ratios (SER1%) and charge enhancement coefficients (CEC1%) were introduced. The SER1%, (defined as the quotient of total oligonucleotide ion abundances with 1 % m-NBA divided by total oligonucleotide abundance without m-NBA) was found to be greater than unity for every oligonucleotide tested. The CEC1% values (defined as the average charge state in the presence of 1 % m-NBA minus the average charge state in the absence of m-NBA) were found to be uniformly positive. Upon close inspection, the degree of charge enhancement for longer oligonucleotides was found to be dependent upon thymine density (i.e., the number and the location of phospho-thymidine units). A correlation between the charge enhancement induced by the presence of m-NBA and the apparent gas-phase acidity (largely determined by the sequence of thymine units but also by the presence of protons on other nucleobases) of multiply deprotonated oligonucleotide species, was thus established. Ammonium cations appeared to be directly involved in the m-NBA supercharging mechanism, and their role seems to be consistent with previously postulated ESI mechanisms describing desorption/ionization of single-stranded DNA into the gas phase.

  20. Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

    Directory of Open Access Journals (Sweden)

    Christoph Schreyvogel

    2016-11-01

    Full Text Available In this paper, we demonstrate an active and fast control of the charge state and hence of the optical and electronic properties of single and near-surface nitrogen-vacancy centres (NV centres in diamond. This active manipulation is achieved by using a two-dimensional Schottky-diode structure from diamond, i.e., by using aluminium as Schottky contact on a hydrogen terminated diamond surface. By changing the applied potential on the Schottky contact, we are able to actively switch single NV centres between all three charge states NV+, NV0 and NV− on a timescale of 10 to 100 ns, corresponding to a switching frequency of 10–100 MHz. This switching frequency is much higher than the hyperfine interaction frequency between an electron spin (of NV− and a nuclear spin (of 15N or 13C for example of 2.66 kHz. This high-frequency charge state switching with a planar diode structure would open the door for many quantum optical applications such as a quantum computer with single NVs for quantum information processing as well as single 13C atoms for long-lifetime storage of quantum information. Furthermore, a control of spectral emission properties of single NVs as a single photon emitters – embedded in photonic structures for example – can be realized which would be vital for quantum communication and cryptography.

  1. Hippocampal and neocortical metabolite ratio in patients with complex partial seizure: short TE and long TE techniques using single voxel proton MR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin Il; Kim, Dong Ik; Lee, Byung In; Lee, Seung Ik; Yoon, Pyeong Ho [Medical College, Yonsei University, Seoul (Korea, Republic of)

    2000-08-01

    To compare hippocampal and neocortical metabolite ratios using single-voxel proton MR spectroscopy with different echo times in patients with complex partial seizure. Using a GE Signa 1.5T scanner with STEAM and PRESS sequences, automated single voxel proton MRS was used to determine metabolite ratio differences in the hippocampus and neocortex of nine complex partial seizure patients (mesial temporal sclerosis (n=3D5), status epilepticus (n=3D1), tumor (n=3D1), cortical dysplasia (n=3D1), occipital lobe epilepsy (n=3D1)). A total of 20 examinations were performed in the region of the hippocampus (n=3D17), temporal neocortex (n=3D1), and parieto-occipital gray matter (n=3D1). Voxel size range was 5.2-17.4 cm{sup 3}. The calculated creatine (Cr) peak was employed as an internal reference and the relative ratio of N-acetylaspartate (NAA) and choline (Cho) was calculated for both short and long echo times using an automated PROBE/SV (GE Medical Systems) package. Each NAA/Cho ratio obtained using both PRESS and STEAM techniques was compared by means of statistical analysis (paired Student t-test). Using PRESS (long TE, 272 ms), NAA/Cho ratios were successfully calculated in 16 of 20 examinations; in four this was not possible due to noise levels of the Cr and Cho peaks. Using STEAM (short TE, 30 ms) NAA/Cho ratios were successfully calculated in 19 of 20 examinations; in one, the Cho peak could not be measured. Using PRESS and STEAM, mean and standard deviations for the NAA/Cho ratio were 1.22{+-}0.50 and 1.16{+-}0.36, respectively. There were no statistically significant differences in this ratio between the short and long TE method (p less than 0.01). In complex partial seizure patients, no significant metabolite differences were found between short and long echo times of single voxel proton MR spectroscopy. The metabolite ratio at different echo times can be reliably obtained using this simplified and automated PROBE/SV quantitation method. (author)

  2. Effect of body biasing on single-event induced charge collection in deep N-well technology

    International Nuclear Information System (INIS)

    Ding Yi; Hu Jian-Guo; Tan Hong-Zhou; Qin Jun-Rui

    2015-01-01

    As the device size decreases, the soft error induced by space ions is becoming a great concern for the reliability of integrated circuits (ICs). At present, the body biasing technique is widely used in highly scaled technologies. In the paper, using the three-dimensional technology computer-aided design (TCAD) simulation, we analyze the effect of the body biasing on the single-event charge collection in deep N-well technology. Our simulation results show that the body biasing mainly affects the behavior of the source, and the effect of body biasing on the charge collection for the nMOSFET and pMOSFET is quite different. For the nMOSFET, the RBB will increase the charge collection, while the FBB will reduce the charge collection. For the pMOSFET, the effect of RBB on the SET pulse width is small, while the FBB has an adverse effect. Moreover, the differenceof the effect of body biasing on the charge collection is compared in deep N-well and twin well. (paper)

  3. Study of the Bulk Charge Carrier Dynamics in Anatase and Rutile TiO2 Single Crystals by Femtosecond Time Resolved Spectroscopy

    KAUST Repository

    Maity, Partha

    2018-04-02

    Understanding of the fundamentals behind charge carriers of photo-catalytic materials are still illusive hindering progress in our quest for renewable energy. TiO2 anatase and rutile are the most understood phases in photo-catalysis and serve as the best model for fundamental studies. Their ultrafast charge carrier dynamics especially on TiO2 anatase single crystal (the most active phase) are unresolved. Here femtosecond time resolved spectroscopy (TRS) was carried out to explore the dynamics of photo-excited charge carriers’ recombination in anatase single crystal, for the first time using pump fluence effects, and compares it to that of the rutile single crystal. A significant difference in charge carrier recombination rates between both crystals is observed. We found that the time constants for carrier recombination are two orders of magnitude slower for anatase (101) when compared to those of rutile (110). Moreover, bulk defects introduced by reduction of the samples via annealing in ultra-high vacuum resulted in faster recombination rates for both polymorphs. Both states (fresh and reduced) probed by pump fluence dependence measurements revealed that the major recombination channel in fresh and reduced anatase and reduced rutile is the first-order Shockley–Reed mediated. However, for fresh rutile, third-body Auger recombination was observed, attributed to the presence of higher density of intrinsic charge carriers. At all excitation wavelengths and fluence investigated, anatase (101) single crystal show longer charge carrier lifetime when compared to rutile (110) single. This may explain the superiority of the anatase phase for the electron transfer H+ reduction to molecular hydrogen.

  4. Intrinsic Charge Carrier Mobility in Single-Layer Black Phosphorus.

    Science.gov (United States)

    Rudenko, A N; Brener, S; Katsnelson, M I

    2016-06-17

    We present a theory for single- and two-phonon charge carrier scattering in anisotropic two-dimensional semiconductors applied to single-layer black phosphorus (BP). We show that in contrast to graphene, where two-phonon processes due to the scattering by flexural phonons dominate at any practically relevant temperatures and are independent of the carrier concentration n, two-phonon scattering in BP is less important and can be considered negligible at n≳10^{13}  cm^{-2}. At smaller n, however, phonons enter in the essentially anharmonic regime. Compared to the hole mobility, which does not exhibit strong anisotropy between the principal directions of BP (μ_{xx}/μ_{yy}∼1.4 at n=10^{13} cm^{-2} and T=300  K), the electron mobility is found to be significantly more anisotropic (μ_{xx}/μ_{yy}∼6.2). Absolute values of μ_{xx} do not exceed 250 (700)  cm^{2} V^{-1} s^{-1} for holes (electrons), which can be considered as an upper limit for the mobility in BP at room temperature.

  5. Single-particle thermal diffusion of charged colloids: Double-layer theory in a temperature gradient

    NARCIS (Netherlands)

    Dhont, J.K.G.; Briels, Willem J.

    2008-01-01

    The double-layer contribution to the single-particle thermal diffusion coefficient of charged, spherical colloids with arbitrary double-layer thickness is calculated and compared to experiments. The calculation is based on an extension of the Debye-Hückel theory for the double-layer structure that

  6. Image charge effects in single-molecule junctions: Breaking of symmetries and negative-differential resistance in a benzene single-electron transistor

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Flensberg, K.

    2011-01-01

    and molecular symmetries remain unclear. Using a theoretical framework developed for semiconductor-nanostructure-based single-electron transistors (SETs), we demonstrate that the image charge interaction breaks the molecular symmetries in a benzene-based single-molecule transistor operating in the Coulomb...... blockade regime. This results in the appearance of a so-called blocking state, which gives rise to negative-differential resistance (NDR). We show that the appearance of NDR and its magnitude in the symmetry-broken benzene SET depends in a complicated way on the interplay between the many-body matrix...

  7. On the charge transfer between single-walled carbon nanotubes and graphene

    International Nuclear Information System (INIS)

    Rao, Rahul; Pierce, Neal; Dasgupta, Archi

    2014-01-01

    It is important to understand the electronic interaction between single-walled carbon nanotubes (SWNTs) and graphene in order to use them efficiently in multifunctional hybrid devices. Here, we deposited SWNT bundles on graphene-covered copper and SiO 2 substrates by chemical vapor deposition and investigated the charge transfer between them by Raman spectroscopy. Our results revealed that, on both copper and SiO 2 substrates, graphene donates electrons to the SWNTs, resulting in p-type doped graphene and n-type doped SWNTs.

  8. Plasmon excitation in single wall carbon nanotubes by penetrating charged particles

    International Nuclear Information System (INIS)

    Segui, Silvina; Gervasoni, Juana L; Arista, Néstor R; Mowbray, Duncan J; Mišković, Zoran L

    2012-01-01

    In this work we study the excitation of plasmons due to the incidence of a charged particle passing through a single wall carbon nanotube. We use a quantized hydrodynamic, in which the σ and π electrons characteristic of these carbonaceous structures are depicted as two interacting 2-dimensional fluids, to calculate the average number of plasmons excited. We analyze the contribution of the different plasmon modes in a variety of configurations, and study the energy lost by the incident particle.

  9. Detecting beer intake by unique metabolite patterns

    DEFF Research Database (Denmark)

    Gürdeniz, Gözde; Jensen, Morten Georg; Meier, Sebastian

    2016-01-01

    Evaluation of health related effects of beer intake is hampered by the lack of accurate tools for assessing intakes (biomarkers). Therefore, we identified plasma and urine metabolites associated with recent beer intake by untargeted metabolomics and established a characteristic metabolite pattern...... representing raw materials and beer production as a qualitative biomarker of beer intake. In a randomized, crossover, single-blinded meal study (MSt1) 18 participants were given one at a time four different test beverages: strong, regular and non-alcoholic beers and a soft drink. Four participants were...... assigned to have two additional beers (MSt2). In addition to plasma and urine samples, test beverages, wort and hops extract were analyzed by UPLC-QTOF. A unique metabolite pattern reflecting beer metabolome, including metabolites derived from beer raw material (i.e. N-methyl tyramine sulfate and the sum...

  10. The ratio of double to single ionization of helium: The relationship of photon and bare charged particle impact ionization

    International Nuclear Information System (INIS)

    Manson, S.T.

    1994-01-01

    In this paper the author derives expressions for the ratio of double to single ionization of helium from its ground state, by both single photons, and charged particle impact. He shows that in the limit of large reduced incident energy T of a charged particle, that the ratio of the double to single ionization cross sections at some energy transfer ΔE is equal to the ratio of photoionization cross sections for a photon of energy hν = ΔE, independent of T. He then goes on to find a relationship for this ionization ratio which is not restricted to some specific energy transfer, and shows that the double to single ionization cross section ratio approaches an asymtotic limit for large enough T

  11. STM studies of an atomic-scale gate electrode formed by a single charged vacancy in GaAs

    Science.gov (United States)

    Lee, Donghun; Daughton, David; Gupta, Jay

    2009-03-01

    Electric-field control of spin-spin interactions at the atomic level is desirable for the realization of spintronics and spin-based quantum computation. Here we demonstrate the realization of an atomic-scale gate electrode formed by a single charged vacancy on the GaAs(110) surface[1]. We can position these vacancies with atomic precision using the tip of a home-built, low temperature STM. Tunneling spectroscopy of single Mn acceptors is used to quantify the electrostatic field as a function of distance from the vacancy. Single Mn acceptors are formed by substituting Mn adatoms for Ga atoms in the first layer of the p-GaAs(110) surface[2]. Depending on the distance, the in-gap resonance of single Mn acceptors can shift as much as 200meV. Our data indicate that the electrostatic field decays according to a screened Coulomb potential. The charge state of the vacancy can be switched to neutral, as evidenced by the Mn resonance returning to its unperturbed position. Reversible control of the local electric field as well as charged states of defects in semiconductors can open new insights such as realizing an atomic-scale gate control and studying spin-spin interactions in semiconductors. http://www.physics.ohio-state.edu/sim jgupta [1] D. Lee and J.A. Gupta (in preparation) [2] D. Kitchen et al., Nature 442, 436-439 (2006)

  12. Charge-odd and single-spin effects in two pion production in ep bar collisions

    International Nuclear Information System (INIS)

    Galynskij, M.V.; Kuraev, E.A.; Shajkhatdenov, B.G.; Ratcliffe, P.G.

    2000-01-01

    We consider two-photon and Bremsstrahlung mechanisms for the production of two charged pions in high-energy electron (proton) scattering off a transversely polarised proton. Interference between the relevant amplitudes generates a charge-odd contribution to the cross section for the process. In a kinematics with a jet moving along electron spin-independent part may be used for determination of phase differences for pion-pion scattering in the states with orbital momentum 0 or 2 and 1 whereas in a kinematics with a jet moving along proton spin-dependent part may be used to explain the experimental data for single-spin correlations in the production of negatively charged pions. We also discuss the backgrounds and estimate the accuracy of the results at less than 10% level. In addition simplified formulae derived for specific kinematics, with small total transverse pion momentum, are given

  13. Charge exchange between singly ionized helium ions

    International Nuclear Information System (INIS)

    Choi, B.H.; Poe, R.T.; Tang, K.T.

    1978-01-01

    The plane-wave Born approximation was used to evaluate the charge transfer cross sections for the reaction He + + He + → He ++ + He. The charge transfer cross section is graphed as a function of incident energy and compared with experimental measurements

  14. Controlling charge on levitating drops.

    Science.gov (United States)

    Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

    2007-08-01

    Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation.

  15. Ionization in matrix-assisted laser desorption/ionization: singly charged molecular ions are the lucky survivors.

    Science.gov (United States)

    Karas, M; Glückmann, M; Schäfer, J

    2000-01-01

    A new model for the ionization processes in UV matrix-assisted laser desorption/ionization (MALDI) which accounts for the major phenomena observed is presented and discussed. The model retains elements of earlier approaches, such as photoionization and photochemical reactions, but it redefines these in the light of new working questions, most importantly why only singly charged ions are detected. Based on experimental evidence, the formation of singly and multiply charged clusters by a deficiency/excess of ions and also by photoionization and subsequent photochemical processes is pointed out to be the major ionization processes, which typically occur in parallel. The generation of electrons and their partial loss into the surrounding vacuum and solid, on the one hand, results in a positively charged ion-neutral plume facilitating a high overall ionization yield. On the other hand, these electrons, and also the large excess of protonated matrix ions in the negative ion mode, induce effective ion reneutralization in the plume. These neutralization processes are most effective for the highly charged cluster ions initially formed. Their fragmentation behaviour is evidenced in fast metastable fragmentation characteristics and agrees well with an electron capture dissociation mechanism and the enthalpy transfer upon neutralization forms the rationale for the prominent fragmentation and intense chemical noise accompanying successful MALDI. Within the course of the paper, cross-correlations with other desorption/ionization techniques and with earlier discussions on their mechanisms are drawn. Copyright 2000 John Wiley & Sons, Ltd.

  16. Identification and Partial Structural Characterization of Mass Isolated Valsartan and Its Metabolite with Messenger Tagging Vibrational Spectroscopy

    Science.gov (United States)

    Gorlova, Olga; Colvin, Sean M.; Brathwaite, Antonio; Menges, Fabian S.; Craig, Stephanie M.; Miller, Scott J.; Johnson, Mark A.

    2017-08-01

    Recent advances in the coupling of vibrational spectroscopy with mass spectrometry create new opportunities for the structural characterization of metabolites with great sensitivity. Previous studies have demonstrated this scheme on 300 K ions using very high power free electron lasers in the fingerprint region of the infrared. Here we extend the scope of this approach to a single investigator scale as well as extend the spectral range to include the OH stretching fundamentals. This is accomplished by detecting the IR absorptions in a linear action regime by photodissociation of weakly bound N2 molecules, which are attached to the target ions in a cryogenically cooled, rf ion trap. We consider the specific case of the widely used drug Valsartan and two isomeric forms of its metabolite. Advantages and challenges of the cold ion approach are discussed, including disentangling the role of conformers and the strategic choices involved in the selection of the charging mechanism that optimize spectral differentiation among candidate structural isomers. In this case, the Na+ complexes are observed to yield sharp resonances in the high frequency NH and OH stretching regions, which can be used to easily differentiate between two isomers of the metabolite. [Figure not available: see fulltext.

  17. A Simple Fractionated Extraction Method for the Comprehensive Analysis of Metabolites, Lipids, and Proteins from a Single Sample.

    Science.gov (United States)

    Salem, Mohamed; Bernach, Michal; Bajdzienko, Krzysztof; Giavalisco, Patrick

    2017-06-01

    Understanding of complex biological systems requires the measurement, analysis and integration of multiple compound classes of the living cell, usually determined by transcriptomic, proteomic, metabolomics and lipidomic measurements. In this protocol, we introduce a simple method for the reproducible extraction of metabolites, lipids and proteins from biological tissues using a single aliquot per sample. The extraction method is based on a methyl tert-butyl ether: methanol: water system for liquid: liquid partitioning of hydrophobic and polar metabolites into two immiscible phases along with the precipitation of proteins and other macromolecules as a solid pellet. This method, therefore, provides three different fractions of specific molecular composition, which are fully compatible with common high throughput 'omics' technologies such as liquid chromatography (LC) or gas chromatography (GC) coupled to mass spectrometers. Even though the method was initially developed for the analysis of different plant tissue samples, it has proved to be fully compatible for the extraction and analysis of biological samples from systems as diverse as algae, insects, and mammalian tissues and cell cultures.

  18. Charge transfer at junctions of a single layer of graphene and a metallic single walled carbon nanotube.

    Science.gov (United States)

    Paulus, Geraldine L C; Wang, Qing Hua; Ulissi, Zachary W; McNicholas, Thomas P; Vijayaraghavan, Aravind; Shih, Chih-Jen; Jin, Zhong; Strano, Michael S

    2013-06-10

    Junctions between a single walled carbon nanotube (SWNT) and a monolayer of graphene are fabricated and studied for the first time. A single layer graphene (SLG) sheet grown by chemical vapor deposition (CVD) is transferred onto a SiO₂/Si wafer with aligned CVD-grown SWNTs. Raman spectroscopy is used to identify metallic-SWNT/SLG junctions, and a method for spectroscopic deconvolution of the overlapping G peaks of the SWNT and the SLG is reported, making use of the polarization dependence of the SWNT. A comparison of the Raman peak positions and intensities of the individual SWNT and graphene to those of the SWNT-graphene junction indicates an electron transfer of 1.12 × 10¹³ cm⁻² from the SWNT to the graphene. This direction of charge transfer is in agreement with the work functions of the SWNT and graphene. The compression of the SWNT by the graphene increases the broadening of the radial breathing mode (RBM) peak from 3.6 ± 0.3 to 4.6 ± 0.5 cm⁻¹ and of the G peak from 13 ± 1 to 18 ± 1 cm⁻¹, in reasonable agreement with molecular dynamics simulations. However, the RBM and G peak position shifts are primarily due to charge transfer with minimal contributions from strain. With this method, the ability to dope graphene with nanometer resolution is demonstrated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Mode locking of electron spin coherences in singly charged quantum dots.

    Science.gov (United States)

    Greilich, A; Yakovlev, D R; Shabaev, A; Efros, Al L; Yugova, I A; Oulton, R; Stavarache, V; Reuter, D; Wieck, A; Bayer, M

    2006-07-21

    The fast dephasing of electron spins in an ensemble of quantum dots is detrimental for applications in quantum information processing. We show here that dephasing can be overcome by using a periodic train of light pulses to synchronize the phases of the precessing spins, and we demonstrate this effect in an ensemble of singly charged (In,Ga)As/GaAs quantum dots. This mode locking leads to constructive interference of contributions to Faraday rotation and presents potential applications based on robust quantum coherence within an ensemble of dots.

  20. Ultrafast electron microscopy: Instrument response from the single-electron to high bunch-charge regimes

    Science.gov (United States)

    Plemmons, Dayne A.; Flannigan, David J.

    2017-09-01

    We determine the instrument response of an ultrafast electron microscope equipped with a conventional thermionic electron gun and absent modifications beyond the optical ports. Using flat, graphite-encircled LaB6 cathodes, we image space-charge effects as a function of photoelectron-packet population and find that an applied Wehnelt bias has a negligible effect on the threshold levels (>103 electrons per pulse) but does appear to suppress blurring at the upper limits (∼105 electrons). Using plasma lensing, we determine the instrument-response time for 700-fs laser pulses and find that single-electron packets are laser limited (1 ps), while broadening occurs well below the space-charge limit.

  1. Hippocampal and neocortical metabolite ratio in patients with complex partial seizure: short TE and long TE techniques using single voxel proton MR spectroscopy

    International Nuclear Information System (INIS)

    Chung, Jin Il; Kim, Dong Ik; Lee, Byung In; Lee, Seung Ik; Yoon, Pyeong Ho

    2000-01-01

    To compare hippocampal and neocortical metabolite ratios using single-voxel proton MR spectroscopy with different echo times in patients with complex partial seizure. Using a GE Signa 1.5T scanner with STEAM and PRESS sequences, automated single voxel proton MRS was used to determine metabolite ratio differences in the hippocampus and neocortex of nine complex partial seizure patients (mesial temporal sclerosis (n=3D5), status epilepticus (n=3D1), tumor (n=3D1), cortical dysplasia (n=3D1), occipital lobe epilepsy (n=3D1)). A total of 20 examinations were performed in the region of the hippocampus (n=3D17), temporal neocortex (n=3D1), and parieto-occipital gray matter (n=3D1). Voxel size range was 5.2-17.4 cm 3 . The calculated creatine (Cr) peak was employed as an internal reference and the relative ratio of N-acetylaspartate (NAA) and choline (Cho) was calculated for both short and long echo times using an automated PROBE/SV (GE Medical Systems) package. Each NAA/Cho ratio obtained using both PRESS and STEAM techniques was compared by means of statistical analysis (paired Student t-test). Using PRESS (long TE, 272 ms), NAA/Cho ratios were successfully calculated in 16 of 20 examinations; in four this was not possible due to noise levels of the Cr and Cho peaks. Using STEAM (short TE, 30 ms) NAA/Cho ratios were successfully calculated in 19 of 20 examinations; in one, the Cho peak could not be measured. Using PRESS and STEAM, mean and standard deviations for the NAA/Cho ratio were 1.22±0.50 and 1.16±0.36, respectively. There were no statistically significant differences in this ratio between the short and long TE method (p less than 0.01). In complex partial seizure patients, no significant metabolite differences were found between short and long echo times of single voxel proton MR spectroscopy. The metabolite ratio at different echo times can be reliably obtained using this simplified and automated PROBE/SV quantitation method. (author)

  2. Dielectric Losses and Charge Transfer in Antimony-Doped TlGaS2 Single Crystal

    Science.gov (United States)

    Asadov, S. M.; Mustafaeva, S. N.

    2018-03-01

    Effect of semimetallic antimony (0.5 mol % Sb) on the dielectric properties and ac-conductivity of TlGaS2-based single crystals grown by the Bridgman-Stockbarger method has been studied. The experimental results on the frequency dispersion of dielectric coefficients and the conductivity of TlGa0.995Sb0.005S2 single crystals allowed the revealing of the dielectric loss nature, the charge transfer mechanism, and the estimation of the parameters of the states localized in the energy gap. The antimony-doping of the TlGaS2 single crystal leads to an increase in the density of states near the Fermi level and a decrease in the average time and average distance of hopes.

  3. Study of Charge-Dependent Transport and Toxicity of Peptide-Functionalized Silver Nanoparticles Using Zebrafish Embryos and Single Nanoparticle Plasmonic Spectroscopy

    Science.gov (United States)

    Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Xu, Xiao-Hong Nancy

    2013-01-01

    Nanomaterials possess unusually high surface area-to-volume ratios, and surface-determined physicochemical properties. It is essential to understand their surface-dependent toxicity in order to rationally design biocompatible nanomaterials for a wide variety of applications. In this study, we have functionalized the surfaces of silver nanoparticles (Ag NPs, 11.7 ± 2.7 nm in diameters) with three biocompatible peptides (CALNNK, CALNNS, CALNNE) to prepare positively (Ag-CALNNK NPs+ζ), negatively (Ag-CALNNS NPs−2ζ), and more negatively charged NPs (Ag-CALNNE NPs−4ζ), respectively. Each peptide differs in a single amino acid at its C-terminus, which minimizes the effects of peptide sequences and serves as a model molecule to create positive, neutral and negative charges on the surface of the NPs at pH 4–10. We have studied their charge-dependent transport into early-developing (cleavage-stage) zebrafish embryos and their effects on embryonic development using dark-field optical microscopy and spectroscopy (DFOMS). We found that all three Ag-peptide NPs passively diffused into the embryos via their chorionic pore canals, and stayed inside the embryos throughout their entire development (120 h), showing charge-independent diffusion modes and charge-dependent diffusion coefficients. Notably, the NPs create charge-dependent toxic effects on embryonic development, showing that the Ag-CALNNK NPs+ζ (positively charged) are the most biocompatible while the Ag-CALNNE NPs–4ζ (more negatively charged) are the most toxic. By comparing with our previous studies of the same sized citrated Ag and Au NPs, the Ag-peptide NPs are much more biocompatible than the citrated Ag NPs, and nearly as biocompatible as the Au NPs, showing the dependence of nanotoxicity upon the surface charges, surface functional groups and chemical compositions of the NPs. This study also demonstrates powerful applications of single NP plasmonic spectroscopy for quantitative analysis of single NPs

  4. The Fate of a Normal Human Cell Traversed by a Single Charged Particle

    Science.gov (United States)

    Fournier, C.; Zahnreich, S.; Kraft, D.; Friedrich, T.; Voss, K.-O.; Durante, M.; Ritter, S.

    2012-01-01

    The long-term “fate” of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour using single-cell cloning. Around 70% of the first cycle cells presented visible aberrations in mFISH after a single ion traversal, and about 5% of the cells were still able to form colonies. In one third of selected high-proliferative colonies we observed clonal (radiation-induced) aberrations. Terminal differentiation and markers of senescence (PCNA, p16) in the descendants of cells traversed by one carbon ion occurred earlier than in controls, but no evidence of radiation-induced chromosomal instability was found. We conclude that cells surviving single-ion traversal, often carrying clonal chromosome aberrations, undergo accelerated senescence but maintain chromosomal stability. PMID:22966418

  5. Fungal and bacterial metabolites in commercial poultry feed from Nigeria.

    Science.gov (United States)

    Ezekiel, C N; Bandyopadhyay, R; Sulyok, M; Warth, B; Krska, R

    2012-08-01

    Metabolites of toxigenic fungi and bacteria occur as natural contaminants (e.g. mycotoxins) in feedstuffs making them unsafe to animals. The multi-toxin profiles in 58 commercial poultry feed samples collected from 19 districts in 17 states of Nigeria were determined by LC/ESI-MS/MS with a single extraction step and no clean-up. Sixty-three (56 fungal and seven bacterial) metabolites were detected with concentrations ranging up to 10,200 µg kg⁻¹ in the case of aurofusarin. Fusarium toxins were the most prevalent group of fungal metabolites, whereas valinomycin occurred in more than 50% of the samples. Twelve non-regulatory fungal and seven bacterial metabolites detected and quantified in this study have never been reported previously in naturally contaminated stored grains or finished feed. Among the regulatory toxins in poultry feed, aflatoxin concentrations in 62% of samples were above 20 µg kg⁻¹, demonstrating high prevalence of unsafe levels of aflatoxins in Nigeria. Deoxynivalenol concentrations exceeded 1000 µg kg⁻¹ in 10.3% of samples. Actions are required to reduce the consequences from regulatory mycotoxins and understand the risks of the single or co-occurrence of non-regulatory metabolites for the benefit of the poultry industry.

  6. Experimental determination of electron shock excitation cross sections for a singly charged gadolinium ion

    International Nuclear Information System (INIS)

    Smirnov, Yu.M.

    1995-01-01

    The trends observed in the processes of excitation with simultaneous ionization have received little study. This is particularly so for rare-earth elements having electron shells of complex structure and optical spectra very rich in lines. Among the basic factors responsible for such a situation, we should mention two: the difficulty presented by theoretical analysis of the processes discussed and the absence of factual information about the excitation cross sections with simultaneous ionization for the majority of rare-earth elements. The aim of the present work is to investigate the excitation of a singly charged gadolinium ion in the collisions of monokinetic electrons with gadolinium atoms. Up to the present time, only the excitation cross sections of a gadolinium atom have been measured, where investigation of the electron shock excitation of gadolinium atoms in their free state is associated with overcoming large experimental difficulties. About 160 crosss sections for the excitation of a singly charged gadolinium ion were measured and for a third of the cross sections; the energy dependences were recorded for the change in energy of the elecrons from the excitation threshold up to 200 eV. Included are tables of the wavelength, transistion, internal quantum number, the energy of the lowere and upper levels, and the values of cross sections for the charged gadolinium ion. Diagrams of the transistion energy states of Gd (II) and spectroscopy are presented and explained

  7. Ionization and single electron capture in collision of highly charged Ar16+ ions with helium

    International Nuclear Information System (INIS)

    Wang Fei; Gou Bingcong

    2008-01-01

    This paper uses the two-centre atomic orbital close-coupling method to study the ionization and the single electron capture in collision of highly charged Ar 16+ ions with He atoms in the velocity range of 1.2–1.9 a.u. The relative importance of single ionization (SI) to single capture (SC) is explored. The comparison between the calculation and experimental data shows that the SI/SC cross section ratios from this work are in good agreement with experimental data. The total single electron ionization cross sections and the total single electron capture cross sections are also given for this collision. The investigation of the partial electron capture cross section shows a general tendency of capture to larger n and l with increasing velocity from 1.2 to 1.9 a.u

  8. Semen quality in Peruvian pesticide applicators: association between urinary organophosphate metabolites and semen parameters

    Directory of Open Access Journals (Sweden)

    Gasco Manuel

    2008-11-01

    Full Text Available Abstract Background Organophosphates are broad class of chemicals widely used as pesticides throughout the world. We performed a cross-sectional study of associations between dialkylphosphate metabolites of organophosphates and semen quality among pesticide applicators in Majes (Arequipa, Peru. Methods Thirty-one men exposed to organophosphate (OP pesticides and 31 non-exposed were recruited (age, 20–60 years. In exposed subjects, semen and a blood sample were obtained one day after the last pesticide application. Subjects were grouped according to levels of OP metabolites in urine. Semen samples were analyzed for sperm concentration, percentage of sperm motility, percentage of normal morphology, semen leucocytes and concentrations of fructose and zinc. Exposure to OP was assessed by measuring six urinary OP metabolites (dimethyl and diethyl phosphates and thiophosphates by gas chromatography using a single flame photometric detector. Results Diethyldithiophosphate (p = 0.04 and diethylthiophosphate (p = 0.02 better reflected occupational pesticide exposure than other OP metabolites. Semen analysis revealed a significant reduction of semen volume and an increase in semen pH in men with OP metabolites. Multiple regression analysis showed that both occupational exposure to pesticides and the time of exposure to pesticides were more closely related to alterations in semen quality parameters than the single measurement of OP metabolites in urine. Conclusion The study demonstrated that occupational exposure to OP pesticides was more closely related to alterations in semen quality than a single measurement of urine OP metabolites. Current measurement of OP metabolites in urine may not reflect the full risk.

  9. Charge transport in single photochromic molecular junctions

    Science.gov (United States)

    Kim, Youngsang; Pietsch, T.; Scheer, Elke; Hellmuth, T.; Pauly, F.; Sysoiev, D.; Huhn, T.; Exner, T.; Groth, U.; Steiner, U.; Erbe, A.

    2012-02-01

    Recently, photoswitchable molecules, i.e. diarylethene, gained significant interest due to their applicability in data storage media, as optical switches, and in novel logic circuits [1]. Diarylethene-derivative molecules are the most promising candidates to design electronic functional elements, because of their excellent thermal stability, high fatigue resistance, and negligible change upon switching [1]. Here, we present the preferential conductance of specifically designed sulfur-free diarylethene molecules [2] bridging the mechanically controlled break-junctions at low temperatures [3]. The molecular energy levels and electrode couplings are obtained by evaluating the current-voltage characteristics using the single-level model [4]. The charge transport mechanism of different types of diarylethene molecules is investigated, and the results are discussed within the framework of novel theoretical predictions. [4pt] [1] M. Del Valle etal., Nat Nanotechnol 2, 176 (2007) S. J. van der Molen etal., Nano. Lett. 9, 76 (2009).[0pt] [2] D. Sysoiev etal., Chem. Eur. J. 17, 6663 (2011).[0pt] [3] Y. Kim etal., Phys. Rev. Lett. 106, 196804 (2011).[0pt] [4] Y. Kim etal., Nano Lett. 11, 3734 (2011). L. Zotti etal., Small 6, 1529 (2010).

  10. Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Palumbo, Fabrizio [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Garcia-Lainez, Guillermo [Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026 Valencia (Spain); Limones-Herrero, Daniel [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Coloma, M. Dolores; Escobar, Javier [Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026 Valencia (Spain); Jiménez, M. Consuelo [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Miranda, Miguel A., E-mail: mmiranda@qim.upv.es [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); and others

    2016-12-15

    Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity. - Highlights: • Demethylated CPZ metabolites are phototoxic to cells, as revealed by the NRU assay. • Single cell electrophoresis (Comet Assay) confirms the photodamage to cellular DNA. • DNA single strand breaks formation is observed on agarose gel electrophoresis.

  11. Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites

    International Nuclear Information System (INIS)

    Palumbo, Fabrizio; Garcia-Lainez, Guillermo; Limones-Herrero, Daniel; Coloma, M. Dolores; Escobar, Javier; Jiménez, M. Consuelo; Miranda, Miguel A.

    2016-01-01

    Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity. - Highlights: • Demethylated CPZ metabolites are phototoxic to cells, as revealed by the NRU assay. • Single cell electrophoresis (Comet Assay) confirms the photodamage to cellular DNA. • DNA single strand breaks formation is observed on agarose gel electrophoresis.

  12. Metabolite Damage and Metabolite Damage Control in Plants

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Andrew D. [Horticultural Sciences Department and; Henry, Christopher S. [Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois 60439, email:; Computation Institute, University of Chicago, Chicago, Illinois 60637; Fiehn, Oliver [Genome Center, University of California, Davis, California 95616, email:; de Crécy-Lagard, Valérie [Microbiology and Cell Science Department, University of Florida, Gainesville, Florida 32611, email: ,

    2016-04-29

    It is increasingly clear that (a) many metabolites undergo spontaneous or enzyme-catalyzed side reactions in vivo, (b) the damaged metabolites formed by these reactions can be harmful, and (c) organisms have biochemical systems that limit the buildup of damaged metabolites. These damage-control systems either return a damaged molecule to its pristine state (metabolite repair) or convert harmful molecules to harmless ones (damage preemption). Because all organisms share a core set of metabolites that suffer the same chemical and enzymatic damage reactions, certain damage-control systems are widely conserved across the kingdoms of life. Relatively few damage reactions and damage-control systems are well known. Uncovering new damage reactions and identifying the corresponding damaged metabolites, damage-control genes, and enzymes demands a coordinated mix of chemistry, metabolomics, cheminformatics, biochemistry, and comparative genomics. This review illustrates the above points using examples from plants, which are at least as prone to metabolite damage as other organisms.

  13. The dual role of multiple-transistor charge sharing collection in single-event transients

    International Nuclear Information System (INIS)

    Guo Yang; Chen Jian-Jun; He Yi-Bai; Liang Bin; Liu Bi-Wei

    2013-01-01

    As technologies scale down in size, multiple-transistors being affected by a single ion has become a universal phenomenon, and some new effects are present in single event transients (SETs) due to the charge sharing collection of the adjacent multiple-transistors. In this paper, not only the off-state p-channel metal—oxide semiconductor field-effect transistor (PMOS FET), but also the on-state PMOS is struck by a heavy-ion in the two-transistor inverter chain, due to the charge sharing collection and the electrical interaction. The SET induced by striking the off-state PMOS is efficiently mitigated by the pulse quenching effect, but the SET induced by striking the on-state PMOS becomes dominant. It is indicated in this study that in the advanced technologies, the SET will no longer just be induced by an ion striking the off-state transistor, and the SET sensitive region will no longer just surround the off-state transistor either, as it is in the older technologies. We also discuss this issue in a three-transistor inverter in depth, and the study illustrates that the three-transistor inverter is still a better replacement for spaceborne integrated circuit design in advanced technologies. (condensed matter: structural, mechanical, and thermal properties)

  14. Experimental investigations of single-electron detachment processes from H- ions colliding with MeV/u, highly charged ions

    International Nuclear Information System (INIS)

    Tawara, H.; Tonuma, T.; Kumagai, H.; Imai, T.; Uskov, D.B.; Presnyakov, L.P.

    1999-01-01

    Single electron detachment processes from negative hydrogen ions under collisions with MeV/u highly charged ions have been investigated using the so-called crossed-beams technique. The preliminary results of the single-electron detachment cross sections obtained is found to be in crude agreement with some empirical and theoretical estimations. (orig.)

  15. Controlling charges distribution at the surface of a single GaN nanowire by in-situ strain

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2017-08-01

    Full Text Available Effect of the strain on the charge distribution at the surface of a GaN semiconductor nanowire (NW has been investigated inside transmission electron microscope (TEM by in-situ off-axis electron holography. The outer and inner surfaces of the NW bent axially under compression of two Au electrodes were differently strained, resulting in difference of their Fermi levels. Consequently, the free electrons flow from the high Fermi level to the low level until the two Fermi levels aligned in a line. The potential distributions induced by charge redistribution in the two vacuum sides of the bent NW were examined respectively, and the opposite nature of the bounded charges on the outer and inner surfaces of the bent NW was identified. The results provide experimental evidence that the charge distribution at the surfaces of a single GaN NW can be controlled by different strains created along the NW.

  16. Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

    Directory of Open Access Journals (Sweden)

    Raúl García

    2015-06-01

    Full Text Available We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10−7 G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species.

  17. Non-Covalent Interactions and Impact of Charge Penetration Effects in Linear Oligoacene Dimers and Single Crystals

    KAUST Repository

    Ryno, Sean; Risko, Chad; Bredas, Jean-Luc

    2016-01-01

    of charge penetration, which is shown to account for up to 50% of the total interaction energy in dimers extracted from the experimental single crystals; in the case of the most stable co-facial model dimers, this contribution is even larger than the total

  18. Single-electron charging effects

    International Nuclear Information System (INIS)

    Ruggiero, S.T.

    1990-01-01

    The status of our project on single-electron tunneling is at this point excellent. As outlined in our original proposal, a key goal in the development of this project was the demonstration and exploration of the microwave properties of single-electron systems. As discussed here, such work has to date been carried out

  19. Single-electron charging effects

    International Nuclear Information System (INIS)

    Ruggiero, S.T.

    1991-01-01

    The status of our project on single-electron tunneling is, again, excellent. As outlined in our original proposal, a key goal in the development of this project was the demonstration and exploration of the microwave properties of single-electron system. As discussed in this paper such work has to data been carried out. Also as discussed in our previous progress report, the next step in the experimental evolution of the project will be to use lithographically-defined small dots as capacitors as outlined in our proposal. At this point we have made such microdotsdots as will be discussed. We have also continued our work with metal droplets to form single-electron tunnel systems

  20. Single-kernel analysis of fumonisins and other fungal metabolites in maize from South African subsistence farmers.

    Science.gov (United States)

    Mogensen, J M; Sørensen, S M; Sulyok, M; van der Westhuizen, L; Shephard, G S; Frisvad, J C; Thrane, U; Krska, R; Nielsen, K F

    2011-12-01

    Fumonisins are important Fusarium mycotoxins mainly found in maize and derived products. This study analysed maize from five subsistence farmers in the former Transkei region of South Africa. Farmers had sorted kernels into good and mouldy quality. A total of 400 kernels from 10 batches were analysed; of these 100 were visually characterised as uninfected and 300 as infected. Of the 400 kernels, 15% were contaminated with 1.84-1428 mg kg(-1) fumonisins, and 4% (n=15) had a fumonisin content above 100 mg kg(-1). None of the visually uninfected maize had detectable amounts of fumonisins. The total fumonisin concentration was 0.28-1.1 mg kg(-1) for good-quality batches and 0.03-6.2 mg kg(-1) for mouldy-quality batches. The high fumonisin content in the batches was apparently caused by a small number (4%) of highly contaminated kernels, and removal of these reduced the average fumonisin content by 71%. Of the 400 kernels, 80 were screened for 186 microbial metabolites by liquid chromatography-tandem mass spectrometry, detecting 17 other fungal metabolites, including fusaric acid, equisetin, fusaproliferin, beauvericin, cyclosporins, agroclavine, chanoclavine, rugulosin and emodin. Fusaric acid in samples without fumonisins indicated the possibility of using non-toxinogenic Fusaria as biocontrol agents to reduce fumonisin exposure, as done for Aspergillus flavus. This is the first report of mycotoxin profiling in single naturally infected maize kernels. © 2011 Taylor & Francis

  1. Coherent single pion production by antineutrino charged current interactions and test of PCAC

    Science.gov (United States)

    Marage, P.; Aderholz, M.; Allport, P.; Armenise, N.; Baton, J. P.; Berggren, M.; Bertrand, D.; Brisson, V.; Bullock, F. W.; Burkot, W.; Calicchio, M.; Clayton, E. F.; Coghen, T.; Cooper-Sarkar, A. M.; Erriquez, O.; Fitch, P. J.; Gerbier, G.; Guy, J.; Hamisi, F.; Hulth, P. O.; Jones, G. T.; Kasper, P.; Klein, H.; Middleton, R. P.; Miller, D. B.; Mobayyen, M. M.; Morrison, D. R. O.; Natali, S.; Neveu, M.; O'Neale, S. W.; Parker, M. A.; Petiau, P.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; Vallée, C.; Varvell, K.; Vayaki, A.; Venus, W.; Wachsmuth, H.; Wells, J.; Wittek, W.

    1986-06-01

    The cross section for coherent production of a single π- meson in charged current antineutrino interactions on neon nuclei has been measured in BEBC to be (175±25) 10-40 cm2/neon nucleus, averaged over the energy spectrum of the antineutrino wide band beam at the CERN SPS; this corresponds to (0.9±0.1) % of the total charged currentbar v_μ cross section. The distributions of kinematical variables are in agreement with theoretical predictions based on the PCAC hypothesis and the meson dominance model; in particular, the Q 2 dependence is well described by a propagator containing a mass m=(1.35±0.18) GeV. The absolute value of the cross section is also in agreement with the model. This analysis thus provides a test of the PCAC hypothesis in the antineutrino energy range 5 150 GeV.

  2. Coherent single pion production by antineutrino charged current interactions and test of PCAC

    International Nuclear Information System (INIS)

    Marage, P.; Bertrand, D.; Sacton, J.; Aderholz, M.; Wittek, W.; Allport, P.; Wells, J.; Baton, J.P.; Gerbier, G.; Neveu, M.; Clayton, E.F.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Cooper-Sarkar, A.M.; Guy, J.; Kasper, P.; Venus, W.; Klein, H.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Simopoulou, E.; Vayaki, A.

    1986-01-01

    The cross section for coherent production of a single π - meson in charged current antineutrino interactions on neon nuclei has been measured in BEBC to be (175+-25) 10 -40 cm 2 /neon nucleus, averaged over the energy spectrum of the antineutrino wide band beam at the CERN SPS; this corresponds to (0.9+-0.1)% of the total charged current anti νsub(μ) cross section. The distributions of kinematical variables are in agreement with theoretical predictions based on the PCAC hypothesis and the meson dominance model; in particular, the Q 2 dependence is well described by a propagator containing a mass m=(1.35+-0.18)GeV. The absolute value of the cross section is also in agreement with the model. This analysis thus provides a test of the PCAC hypothesis in the antineutrino energy range 5-150 GeV. (orig.)

  3. A study of single-meson production in neutrino and antineutrino charged-current interactions on protons

    Science.gov (United States)

    Allen, P.; Grässler, H.; Schulte, R.; Jones, G. T.; Kennedy, B. W.; O'Neale, S. W.; Gebel, W.; Hofmann, E.; Klein, H.; Mittendorfer, J.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Barnham, K. W. J.; Clayton, E. F.; Hamisi, F.; Miller, D. B.; Mobayyen, M. M.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Saitta, B.; Shotton, P. N.; Towers, S. J.; Aachen-Birmingham-Bonn-CERN-London IC-Munich (MPI)-Oxford Collaboration

    1986-01-01

    We present results on exclusive single-charged pion and kaon production in neutrino and antineutrino interactions on protons in the energy range from 5 to 120 GeV. The data were obtained from exposures of BEBC to wide band beams at the CERN SPS. For invariant masses of the (pπ) system below 2 GeV, the pions originate predominantly from decays of baryon resonances excited by the weak charged current. Similarly, we observe the production of Λ(1520) decaying into p and K -. For invariant masses above 2 GeV pion production becomes peripheral by interaction of the weak current with a virtual π0. We establish a contribution of longitudinally polarised intermediate vector bosons to this process.

  4. Detection of singly- and doubly-charged quaternary ammonium drugs in equine urine by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Ho, Emmie N M; Kwok, W H; Wong, April S Y; Wan, Terence S M

    2012-01-13

    Quaternary ammonium drugs (QADs) are anticholinergic agents some of which are known to have been abused or misused in equine sports. A recent review of literature shows that the screening methods reported thus far for QADs mainly cover singly-charged QADs. Doubly-charged QADs are extremely polar substances which are difficult to be extracted and poorly retained on reversed-phase columns. It would be ideal if a comprehensive method can be developed which can detect both singly- and doubly-charged QADs. This paper describes an efficient liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the simultaneous detection and confirmation of 38 singly- and doubly-charged QADs at sub-parts-per-billion (ppb) to low-ppb levels in equine urine after solid-phase extraction. Quaternary ammonium drugs were extracted from equine urine by solid-phase extraction (SPE) using an ISOLUTE(®) CBA SPE column and analysed by LC/MS/MS in the positive electrospray ionisation mode. Separation of the 38 QADs was achieved on a polar group embedded C18 LC column with a mixture of aqueous ammonium formate (pH 3.0, 10 mM) and acetonitrile as the mobile phase. Detection and confirmation of the 38 QADs at sub-ppb to low-ppb levels in equine urine could be achieved within 16 min using selected reaction monitoring (SRM). Matrix interference of the target transitions at the expected retention times was not observed. Other method validation data, including precision and recovery, were acceptable. The method was successfully applied to the analyses of drug-administration samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming

    DEFF Research Database (Denmark)

    Christensen, Tue; Andersen, Kim Allan; Klose, Andreas

    2013-01-01

    This paper considers a minimum-cost network flow problem in a bipartite graph with a single sink. The transportation costs exhibit a staircase cost structure because such types of transportation cost functions are often found in practice. We present a dynamic programming algorithm for solving...... this so-called single-sink, fixed-charge, multiple-choice transportation problem exactly. The method exploits heuristics and lower bounds to peg binary variables, improve bounds on flow variables, and reduce the state-space variable. In this way, the dynamic programming method is able to solve large...... instances with up to 10,000 nodes and 10 different transportation modes in a few seconds, much less time than required by a widely used mixed-integer programming solver and other methods proposed in the literature for this problem....

  6. Accumulative charge separation for solar fuels production: coupling light-induced single electron transfer to multielectron catalysis.

    Science.gov (United States)

    Hammarström, Leif

    2015-03-17

    The conversion and storage of solar energy into a fuel holds promise to provide a significant part of the future renewable energy demand of our societies. Solar energy technologies today generate heat or electricity, while the large majority of our energy is used in the form of fuels. Direct conversion of solar energy to a fuel would satisfy our needs for storable energy on a large scale. Solar fuels can be generated by absorbing light and converting its energy to chemical energy by electron transfer leading to separation of electrons and holes. The electrons are used in the catalytic reduction of a cheap substrate with low energy content into a high-energy fuel. The holes are filled by oxidation of water, which is the only electron source available for large scale solar fuel production. Absorption of a single photon typically leads to separation of a single electron-hole pair. In contrast, fuel production and water oxidation are multielectron, multiproton reactions. Therefore, a system for direct solar fuel production must be able to accumulate the electrons and holes provided by the sequential absorption of several photons in order to complete the catalytic reactions. In this Account, the process is termed accumulative charge separation. This is considerably more complicated than charge separation on a single electron level and needs particular attention. Semiconductor materials and molecular dyes have for a long time been optimized for use in photovoltaic devices. Efforts are made to develop new systems for light harvesting and charge separation that are better optimized for solar fuel production than those used in the early devices presented so far. Significant progress has recently been made in the discovery and design of better homogeneous and heterogeneous catalysts for solar fuels and water oxidation. While the heterogeneous ones perform better today, molecular catalysts based on transition metal complexes offer much greater tunability of electronic and

  7. Detecting Beer Intake by Unique Metabolite Patterns.

    Science.gov (United States)

    Gürdeniz, Gözde; Jensen, Morten Georg; Meier, Sebastian; Bech, Lene; Lund, Erik; Dragsted, Lars Ove

    2016-12-02

    Evaluation of the health related effects of beer intake is hampered by the lack of accurate tools for assessing intakes (biomarkers). Therefore, we identified plasma and urine metabolites associated with recent beer intake by untargeted metabolomics and established a characteristic metabolite pattern representing raw materials and beer production as a qualitative biomarker of beer intake. In a randomized, crossover, single-blinded meal study (MSt1), 18 participants were given, one at a time, four different test beverages: strong, regular, and nonalcoholic beers and a soft drink. Four participants were assigned to have two additional beers (MSt2). In addition to plasma and urine samples, test beverages, wort, and hops extract were analyzed by UPLC-QTOF. A unique metabolite pattern reflecting beer metabolome, including metabolites derived from beer raw material (i.e., N-methyl tyramine sulfate and the sum of iso-α-acids and tricyclohumols) and the production process (i.e., pyro-glutamyl proline and 2-ethyl malate), was selected to establish a compliance biomarker model for detection of beer intake based on MSt1. The model predicted the MSt2 samples collected before and up to 12 h after beer intake correctly (AUC = 1). A biomarker model including four metabolites representing both beer raw materials and production steps provided a specific and accurate tool for measurement of beer consumption.

  8. Charge transfer effects, thermo and photochromism in single crystal CVD synthetic diamond.

    Science.gov (United States)

    Khan, R U A; Martineau, P M; Cann, B L; Newton, M E; Twitchen, D J

    2009-09-09

    We report on the effects of thermal treatment and ultraviolet irradiation on the point defect concentrations and optical absorption profiles of single crystal CVD synthetic diamond. All thermal treatments were below 850 K, which is lower than the growth temperature and unlikely to result in any structural change. UV-visible absorption spectroscopy measurements showed that upon thermal treatment (823 K), various broad absorption features diminished: an absorption band at 270 nm (used to deduce neutral single substitutional nitrogen (N(S)(0)) concentrations) and also two broad features centred at approximately 360 and 520 nm. Point defect centre concentrations as a function of temperature were also deduced using electron paramagnetic resonance (EPR) spectroscopy. Above ∼500 K, we observed a decrease in the concentration of N(S)(0) centres and a concomitant increase in the negatively charged nitrogen-vacancy-hydrogen (NVH) complex (NVH(-)) concentration. Both transitions exhibited an activation energy between 0.6 and 1.2 eV, which is lower than that for the N(S)(0) donor (∼1.7 eV). Finally, it was found that illuminating samples with intense short-wave ultraviolet light recovered the N(S)(0) concentration and also the 270, 360 and 520 nm absorption features. From these results, we postulate a valence band mediated charge transfer process between NVH and single nitrogen centres with an acceptor trap depth for NVH of 0.6-1.2 eV. Because the loss of N(S)(0) concentration is greater than the increase in NVH(-) concentration we also suggest the presence of another unknown acceptor existing at a similar energy to NVH. The extent to which the colour in CVD synthetic diamond is dependent on prior history is discussed.

  9. A study of single-meson production in neutrino and antineutrino charged-current interactions on protons

    International Nuclear Information System (INIS)

    Allen, P.; Graessler, H.; Schulte, R.; Gebel, W.; Hofmann, E.; Barnham, K.W.J.; Clayton, E.F.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Saitta, B.; Shotton, P.N.; Towers, S.J.

    1986-01-01

    We present results on exclusive single-charged pion and kaon production in neutrino and antineutrino interactions on protons in the energy range from 5 to 120 GeV. The data were obtained from exposures of BEBC to wide band beams at the CERN SPS. For invariant masses of the (pπ) system below 2 GeV, the pions originate predominantly from decays of baryon resonances excited by the weak charged current. Similarly, we observe the production of Λ(1520) decaying into p and K - . For invariant masses above 2 GeV pion production becomes peripheral by interaction of the weak current with a virtual π 0 . We establish a contribution of longitudinally polarised intermediate vector bosons to this process. (orig.)

  10. Metabolites of alectinib in human: their identification and pharmacological activity

    Directory of Open Access Journals (Sweden)

    Mika Sato-Nakai

    2017-07-01

    Full Text Available Two metabolites (M4 and M1b in plasma and four metabolites (M4, M6, M1a and M1b in faeces were detected through the human ADME study following a single oral administration of [14C]alectinib, a small-molecule anaplastic lymphoma kinase inhibitor, to healthy subjects. In the present study, M1a and M1b, which chemical structures had not been identified prior to the human ADME study, were identified as isomers of a carboxylate metabolite oxidatively cleaved at the morpholine ring. In faeces, M4 and M1b were the main metabolites, which shows that the biotransformation to M4 and M1b represents two main metabolic pathways for alectinib. In plasma, M4 was a major metabolite and M1b was a minor metabolite. The contribution to in vivo pharmacological activity of these circulating metabolites was assessed from their in vitro pharmacological activity and plasma protein binding. M4 had a similar cancer cell growth inhibitory activity and plasma protein binding to that of alectinib, suggesting its contribution to the antitumor activity of alectinib, whereas the pharmacological activity of M1b was insignificant.

  11. Theoretical analysis of the effect of charge-sharing on the Detective Quantum Efficiency of single-photon counting segmented silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Marchal, J [Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)], E-mail: julien.marchal@diamond.ac.uk

    2010-01-15

    A detector cascaded model is proposed to describe charge-sharing effect in single-photon counting segmented silicon detectors. Linear system theory is applied to this cascaded model in order to derive detector performance parameters such as large-area gain, presampling Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE) as a function of energy detection threshold. This theory is used to model one-dimensional detectors (i.e. strip detectors) where X-ray-generated charge can be shared between two sampling elements, but the concepts developed in this article can be generalized to two-dimensional arrays of detecting elements (i.e. pixels detectors). The zero-frequency DQE derived from this model is consistent with expressions reported in the literature using a different method. The ability of this model to simulate the effect of charge sharing on image quality in the spatial frequency domain is demonstrated by applying it to a hypothetical one-dimensional single-photon counting detector illuminated with a typical mammography spectrum.

  12. Deflection of high energy channeled charged particles by elastically bent silicon single crystals

    International Nuclear Information System (INIS)

    Gibson, W.M.; Kim, I.J.; Pisharodoy, M.; Salman, S.M.; Sun, C.R.; Wang, G.H.; Wijayawardana, R.; Forster, J.S.; Mitchell, I.V.; Baker, S.I.; Carrigan, R.A. Jr.; Toohig, T.E.; Avdeichikov, V.V.; Ellison, J.A.; Siffert, P.

    1984-01-01

    An experiment has been carried out to observe the deflection of charged particles by planar channeling in bent single crystals of silicon for protons with energy up to 180 GeV. Anomolous loss of particles from the center point of a three point bending apparatus was observed at high incident particle energy. This effect has been exploited to fashion a 'dechanneling spectrometer' to study dechanneling effects due to centripital displacement of channeled particle trajectories in a bent crystal. The bending losses generally conform to the predictions of calculations based on a classical model. (orig.)

  13. Plutonium interactions with soil microbial metabolites: effect on plutonium sorption by soil

    International Nuclear Information System (INIS)

    Wildung, R.E.; Garland, T.R.; Rogers, J.E.

    1987-01-01

    To develop an understanding of the mechanisms of plutonium (Pu) complexation and solubilization by soil microorganisms, a broad range of bacteria and fungi were isolated in pure cultures from soil on the basis of metal tolerance and carbon requirements. The organisms were then used in investigations to examine Pu cellular transport, Pu complexation by extracellular metabolites, and the effects of complexation on Pu valence state, chemical form, and solubility in soil. Of the 239 bacteria and 250 fungi isolated from soil, 19 bacteria and 60 fungi were selected for detailed study. Of these organisms, 15 bacteria and 18 fungi grew to form extracellular Pu complexes that increased the concentration of Pu in soil column eluates relative to controls. Elution through soil effectively removed positively charged Pu complexes. Increased Pu mobility in soil resulted from the formation of neutral and negatively charged Pu complexes, which differed with organism type. In the presence of known microbial metabolites and synthetic ligands (DTPA, EDTA, EDDHA), Pu(VI) was reduced to Pu(IV) before complexation, suggesting that Pu(IV) would be the dominant valence state associated with organic complexes in soils. Studies on selected organisms indicated that both active Pu transport and Pu sorption on the cell occurred, and these phenomena, as well as complexation by extracellular metabolites of Pu, were a function of the form of Pu supplied, the organism type and growth characteristics, and the ability of the organism to alter extracellular pH. 18 references, 6 figures, 7 tables

  14. Stochastic heating of a single Brownian particle by charge fluctuations in a radio-frequency produced plasma sheath

    Science.gov (United States)

    Schmidt, Christian; Piel, Alexander

    2015-10-01

    The Brownian motion of a single particle in the plasma sheath is studied to separate the effect of stochastic heating by charge fluctuations from heating by collective effects. By measuring the particle velocities in the ballistic regime and by carefully determining the particle mass from the Epstein drag it is shown that for a pressure of 10 Pa, which is typical of many experiments, the proper kinetic temperature of the Brownian particle remains close to the gas temperature and rises only slightly with particle size. This weak effect is confirmed by a detailed model for charging and charge fluctuations in the sheath. A substantial temperature rise is found for decreasing pressure, which approximately shows the expected scaling with p-2. The system under study is an example for non-equilibrium Brownian motion under the influence of white noise without corresponding dissipation.

  15. Pharmacokinetics of lansoprazole and its main metabolites after single intravenous doses in healthy Chinese subjects.

    Science.gov (United States)

    Zhang, Dan; Yang, Man; Liu, Man; Zhang, Yanan; Wang, Xiaolin; Xiao, Xue; Liu, Huichen

    2012-11-01

    The aim of the study was to evaluate the pharmacokinetics (PK) of lansoprazole (LPZ) and its main metabolites 5'-hydroxy lansoprazole (HLPZ) and lansoprazole sulphone (LPZS) after single intravenous (i.v.) doses of LPZ in healthy Chinese subjects, and the relationship between the cytochrome P450 (CYP) 2C19 phenotypes and the plasma concentrations of LPZS at the time-points in the elimination phase of LPZ. Twelve subjects were given lansoprazole by i.v. infusion. Blood samples were collected at designated time points up to 24 h. Plasma concentrations of LPZ, HLPZ and LPZS were quantified by a selective and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. After single i.v. doses of 15, 30 and 60 mg LPZ, C(max) and area under the plasma concentration-time curve (AUC(0-t)) of LPZ were 725 ± 151, 1480 ± 190, 3130 ± 480 µg · L(-1) and 1690 ± 1210, 3630 ± 2530, 8080 ± 4550 µg · h · L(-1), respectively. LPZ was generally well tolerated in healthy Chinese subjects, and displayed linear PK in the range of 15-60 mg. There were significant differences in the elimination of LPZ and the formation of LPZS between the single CYP2C19 poor metabolizer (PM) and the CYP2C19 extensive metabolizers (EM). The concentration of LPZS at the time-points in the elimination phase of LPZ could be monitored for CYP2C19 phenotyping. As a probe drug for CYP2C19 phenotyping, LPZ for injection might be more suitable than LPZ oral formulations.

  16. Spin properties of charged Mn-doped quantum dota)

    Science.gov (United States)

    Besombes, L.; Léger, Y.; Maingault, L.; Mariette, H.

    2007-04-01

    The optical properties of individual quantum dots doped with a single Mn atom and charged with a single carrier are analyzed. The emission of the neutral, negatively and positively charged excitons coupled with a single magnetic atom (Mn) are observed in the same individual quantum dot. The spectrum of the charged excitons in interaction with the Mn atom shows a rich pattern attributed to a strong anisotropy of the hole-Mn exchange interaction slightly perturbed by a small valence-band mixing. The anisotropy in the exchange interaction between a single magnetic atom and a single hole is revealed by comparing the emission of a charged Mn-doped quantum dot in longitudinal and transverse magnetic field.

  17. Propensity rules for orientation in singly-charged ion-atom collisions

    International Nuclear Information System (INIS)

    Nielsen, S.E.; Dubois, A.; Hansen, J.P.

    1990-01-01

    Orientation effects for electron capture and excitation in singly-charged ion-atom collisions are analysed using the atomic basis impact parameter method with full inclusion of electron translational factors. We find that the orientation preferences previously predicted for excitation in terms of propensity rules may still be observed when capture is present in ion-atom collisions. Furthermore, in spite of intricate behaviour of the direct capture couplings during the collision, we draw some parallel conclusions for the orientation of the capture states. We illustrate these perturbative predictions by close-coupling calculations for H + -Na(3s) collisions where clear propensity for orientation of the H(2p) capture state is demonstrated in impact parameter and velocity dependences. Finally we predict pronounced orientation effects for H(2s) and H(2p) capture in collisions of H + with initially oriented Na(3p) states. (author)

  18. Transparent Flash Memory using Single Ta2O5 Layer for both Charge Trapping and Tunneling Dielectrics

    KAUST Repository

    Hota, Mrinal Kanti

    2017-06-08

    We report reproducible multibit transparent flash memory in which a single solution-derived Ta2O5 layer is used simultaneously as charge trapping and tunneling layer. This is different from conventional flash cells, where two different dielectric layers are typically used. Under optimized programming/erasing operations, the memory device shows excellent programmable memory characteristics with a maximum memory window of ~10 V. Moreover, the flash memory device shows a stable 2-bit memory performance, good reliability, including data retention for more than 104 sec and endurance performance for more than 100 cycles. The use of a common charge trapping and tunneling layer can simplify advanced flash memory fabrication.

  19. Twisted intra-molecular charge transfer investigations of semiorganic triglycine phosphate single crystal for non linear optical applications

    Science.gov (United States)

    Meera, M. R.; Joselin Beaula, T.; Rayar, S. L.; Bena Jothy, V.

    2017-09-01

    NLO materials are gaining importance in technologies such as optical communication, optical computing and dynamic image processing. Many NLO crystals grown by mixing amino acids with various organic and inorganic acids have been reported in the literature. Hence, glycine mixed semi-organic material will be of special interest as a fundamental building block to develop many complex crystals with improved NLO properties. A semi organic Single crystal of Triglycine Phosphate (TGP) which was grown and spectral analysis have been using FTIR and Raman spectral analysis. Natural Bond Orbital Analysis and the atomic natural charges are also predicted. HOMO LUMO energy gap value suggests the possibility of charge transfer within the molecule.

  20. Transparent Flash Memory using Single Ta2O5 Layer for both Charge Trapping and Tunneling Dielectrics

    KAUST Repository

    Hota, Mrinal Kanti; Alshammari, Fwzah H.; Salama, Khaled N.; Alshareef, Husam N.

    2017-01-01

    We report reproducible multibit transparent flash memory in which a single solution-derived Ta2O5 layer is used simultaneously as charge trapping and tunneling layer. This is different from conventional flash cells, where two different dielectric layers are typically used. Under optimized programming/erasing operations, the memory device shows excellent programmable memory characteristics with a maximum memory window of ~10 V. Moreover, the flash memory device shows a stable 2-bit memory performance, good reliability, including data retention for more than 104 sec and endurance performance for more than 100 cycles. The use of a common charge trapping and tunneling layer can simplify advanced flash memory fabrication.

  1. The charge collection in single side silicon microstrip detectors

    CERN Document Server

    Eremin, V V; Roe, S; Ruggiero, G; Weilhammer, Peter

    2003-01-01

    The transient current technique has been used to investigate signal formation in unirradiated silicon microstrip detectors, which are similar in geometry to those developed for the ATLAS experiment at LHC. Nanosecond pulsed infrared and red lasers were used to induce the signals under study. Two peculiarities in the detector performance were observed: an unexpectedly slow rise to the signal induced in a given strip when signals are injected opposite to the strip, and a long duration of the induced signal in comparison with the calculated drift time of charge carriers through the detector thickness - with a significant fraction of the charge being induced after charge carrier arrival. These major effects and details of the detector response for different positions of charge injection are discussed in the context of Ramo's theorem and compared with predictions arising from the more commonly studied phenomenon of signal formation in planar pad detectors.

  2. Single photon emission up to liquid nitrogen temperature from charged excitons confined in GaAs-based epitaxial nanostructures

    NARCIS (Netherlands)

    Dusanowski, L.; Syperek, M.; Marynski, A.; Li, L.H.; Misiewicz, J.; Höfling, S.; Kamp, M.; Fiore, A.; Sek, G.

    2015-01-01

    We demonstrate a non-classical photon emitter at near infrared wavelength based on a single (In,Ga)As/GaAs epitaxially grown columnar quantum dot. Charged exciton complexes have been identified in magneto-photoluminescence. Photon auto-correlation histograms from the recombination of a trion

  3. Ketamine metabolites with antidepressant effects: Fast, economical, and eco-friendly enantioselective separation based on supercritical-fluid chromatography (SFC) and single quadrupole MS detection.

    Science.gov (United States)

    Fassauer, Georg M; Hofstetter, Robert; Hasan, Mahmoud; Oswald, Stefan; Modeß, Christina; Siegmund, Werner; Link, Andreas

    2017-11-30

    Increasing evidence accumulates that metabolites of the dissociative anesthetic ketamine contribute considerably to the biological effects of this drug and could be developed as next generation antidepressants, especially for acute treatment of patients with therapy-refractory major depression. Analytical methods for the simultaneous determination of the plethora of hydroxylated, dehydrogenated and/or demethylated compounds formed after administration of ketamine hydrochloride are a prerequisite for future clinical investigations and a deeper understanding of the individual role of the isomers of these metabolites. In this study, we present development and validation of a method based on supercritical-fluid chromatography (SFC) coupled to single quadrupole MS detection that allows the separation of ketamine as well as all of its relevant metabolites detected in urine of healthy volunteers. Inherently to SFC methods, the run times of the novel protocol are four times shorter than in a comparable HPLC method, the use of organic solvents is reduced and we were able to demonstrate and validate the successful enantioselective separation and quantification of R- and S-ketamine, R- and S-norketamine, R- and S-dehydronorketamine and (2R,6R)- and (2S,6S)-hydroxynorketamine isomers differing in either constitution, stereochemistry, or both, in one run. The developed method may be useful in investigating the antidepressant efficacy of ketamine in clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Cu-O network dependence of optical charge-transfer gaps and spin-pair excitations in single-CuO2-layer compounds

    International Nuclear Information System (INIS)

    Tokura, Y.; Koshihara, S.; Arima, T.; Takagi, H.; Ishibashi, S.; Ido, T.; Uchida, S.

    1990-01-01

    Spectra of optical conductivity and magnon Raman scattering have been investigated in single crystals of a parent family of cuprate superconductors with various types of Cu-O single-layer networks. The analysis of the spectra shows the systematic dependence of the charge-transfer gaps and covalent character of Cu-O bonds on the pattern of the Cu-O network, while the spin-exchange energy is rather convergent for all the single-CuO 2 -sheet compounds

  5. The recent single-tag two-photon experiments at PETRA and the issue of quark charges

    International Nuclear Information System (INIS)

    Godbole, R.M.; Pati, J.C.; Rindani, S.D.; Jayaraman, T.; Rajasekaran, G.

    1984-01-01

    The data of recent single-tag two-photon experiments indicating noticeable excess in (R tildesub(γγ))sup(jet) over fractionally charged quark-parton model-predictions is studied from the point of view of its implications on the gauge integer charge quark model. Focusing attention on the region of psub(T) exceeding about 3 GeV, where higher order QCD and non-perturbative effects might be expected to be small. It is noted that this excess and its Q 2 dependence can be attributed to the presence of a colour component in the electromagnetic current provided the effective mass of the gluon lies between about 150 to 350 MeV. Accurate measurements of R tildesub(γγ) in the high psub(T) region (psub(T) > or approx. 5 GeV) are crucial for an unambiguous distinction between fcq and gauge-icq models. (orig.)

  6. The recent single tag two photon experiments at PETRA and the issue of quark charges

    International Nuclear Information System (INIS)

    Godbole, R.M.; Pati, J.C.; Rindani, S.D.; Jayaraman, T.; Rajasekaran, G.

    1983-11-01

    The data of recent single-tag-two-photon experiments indicating noticeable excess in (R-tildesub(γγ))sup(jet) over fractionally charged quark-parton model-predictions is studied from the point of view of its implications on the gauge integer charge quark model. Focussing attention on the region of psub(T) exceeding about 3 GeV, where higher order QCD and non-perturbative effects might be expected to be small, it is noted that this excess and its Q 2 dependence can be attributed to the presence of a colour component in the electromagnetic current provided the effective mass of the gluon lies between about 150 to 350 MeV. Accurate measurements of R-tildesub(γγ) in the high psub(T) region (psub(T)>or approx.5 GeV) are crucial for an unambiguous distinction between fcq and gauge-icq models. (author)

  7. Detection of Volatile Metabolites of Garlic in Human Breast Milk

    Science.gov (United States)

    Scheffler, Laura; Sauermann, Yvonne; Zeh, Gina; Hauf, Katharina; Heinlein, Anja; Sharapa, Constanze; Buettner, Andrea

    2016-01-01

    The odor of human breast milk after ingestion of raw garlic at food-relevant concentrations by breastfeeding mothers was investigated for the first time chemo-analytically using gas chromatography−mass spectrometry/olfactometry (GC-MS/O), as well as sensorially using a trained human sensory panel. Sensory evaluation revealed a clear garlic/cabbage-like odor that appeared in breast milk about 2.5 h after consumption of garlic. GC-MS/O analyses confirmed the occurrence of garlic-derived metabolites in breast milk, namely allyl methyl sulfide (AMS), allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO2). Of these, only AMS had a garlic-like odor whereas the other two metabolites were odorless. This demonstrates that the odor change in human milk is not related to a direct transfer of garlic odorants, as is currently believed, but rather derives from a single metabolite. The formation of these metabolites is not fully understood, but AMSO and AMSO2 are most likely formed by the oxidation of AMS in the human body. The excretion rates of these metabolites into breast milk were strongly time-dependent with large inter-individual differences. PMID:27275838

  8. Site-resolved neutralization of slow singly and multiply charged ions during large-angle backscattering collisions with RbI(1 0 0)

    CERN Document Server

    Meyer, F W; Vane, C R

    2003-01-01

    Preliminary results are reported of projectile neutralization during 120 deg. backscattering from RbI[1 0 0] of singly and multiply charged incident ions in the keV energy range. Scattered charge fractions are reported for 4.4 keV Ne sup 8 sup + and 4.2 keV F sup + normally incident on the ionic crystal. Collisions associated with scattering from a Rb or I site can be clearly distinguished for each scattered final charge state. Significant differences are observed in the intensities of the higher scattered charge states resulting from collisions with Rb and I sites. In contrast, at the target azimuth orientation of the present measurement, only minor differences in F sup - yield are observed for hard scattering from the two lattice sites.

  9. Production, transport and charge capture measurements of highly charged recoil ions

    International Nuclear Information System (INIS)

    Trebus, U.E.

    1989-01-01

    An experiment is described to study highly charged recoil ions on-line to the heavy accelerator UNILAC at GSI. The highly charged recoil ions are produced by heavy-ion bombardment of a gas target. Subsequently the slow highly charged recoil ions are extracted from the ionization volume, and guided through a beam transport line to a Wien filter for charge state selection and to a collision region to study charge transfer processes. Several experiments were carried out to show the efficient charge state separation. Charge states up to q = 15 were observed. When using a retarding field analyzer cross sections for single electron capture were determined for different charge states of Xe q+ for q = 4 to 11 and He gas. The experiments demonstrated increasing charge transfer cross sections with increasing charge state q and indicated the effect of near resonant charge capture for q = 6. The flexible data acquisition system used, is described and other future experiments, such as for instance in flight ion-trapping are indicated in the appendix

  10. Production, transport and charge capture measurements of highly charged recoil ions

    International Nuclear Information System (INIS)

    Trebus, U.E.

    1989-05-01

    An experiment is described to study highly charged recoil ions on-line to the heavy ion accelerator UNILAC at GSI. The highly charged recoil ions are produced by heavy ion bombardment of a gas target. Subsequently the slow highly charged recoil ions are extracted from the ionization volume, and guided through a beam transport line to a Wien filter for charge state selection and to a collision region to study charge transfer processes. Several experiments were carried out to show the efficient charge state separation. Charge states up to q=15 were observed. When using a retarding field analyzer cross sections for single electron capture were determined for different charge states of Xe q+ for q=4 to 11 and He gas. The experiments demonstrated increasing charge transfer cross sections with increasing charge state q and indicated the effect of near resonant charge capture for q=6. The flexible data acquisition system used, is described and other future experiments, such as for instance in flight ion-trapping are indicated in the appendix. (orig.)

  11. Collisions of singly and doubly charged ions with oxygen molecules in the energy range 1 - 1800 (3600) eV

    International Nuclear Information System (INIS)

    Kuen, I.; Howorka, F.

    1983-01-01

    Absolute cross sections for the excitation of optically emitting states in collisions of He + , Ne + , Ar + , Kr + , B + , He ++ , Ne ++ and Ar ++ with oxygen molecules are measured, the energy range of the ion being1 - 1800 eV Lab for the singly charged and 1 - 3600 eV for the doubly charged ions. Seven important processes can be distinguished: charge exchange excitation of O 2 + band, O I, O II, X I and X II lines (X + , X ++ being the primary ion), direct excitation of X II and double charge exchange excitations. The energy dependences of the excitation cross sections are remarkably different for different processes but similar for one process with different ions. The sum total of all cross sections together for excitations which lead to light emission is on the order of a few square angstroms at 1000 eV c.m. energy. The results are of interest for surface investigations, plasma diagnostics and laser work. (Author)

  12. Variability of Urinary Phthalate Metabolite and Bisphenol A Concentrations before and during Pregnancy

    Science.gov (United States)

    Braun, Joe M.; Smith, Kristen W.; Williams, Paige L.; Calafat, Antonia M.; Berry, Katharine; Ehrlich, Shelley

    2012-01-01

    Background: Gestational phthalate and bisphenol A (BPA) exposure may increase the risk of adverse maternal/child health outcomes, but there are few data on the variability of urinary biomarkers before and during pregnancy. Objective: We characterized the variability of urinary phthalate metabolite and BPA concentrations before and during pregnancy and the ability of a single spot urine sample to classify average gestational exposure. Methods: We collected 1,001 urine samples before and during pregnancy from 137 women who were partners in couples attending a Boston fertility clinic and who had a live birth. Women provided spot urine samples before (n ≥ 2) and during (n ≥ 2) pregnancy. We measured urinary concentrations of monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-iso-butyl phthalate, monobenzyl phthalate (MBzP), four metabolites of di-(2-ethylhexyl) phthalate (DEHP), and BPA. After adjusting for specific gravity, we characterized biomarker variability using intraclass correlation coefficients (ICCs) and conducted several surrogate category analyses to determine whether a single spot urine sample could adequately classify average gestational exposure. Results: Absolute concentrations of phthalate metabolites and BPA were similar before and during pregnancy. Variability was higher during pregnancy than before pregnancy for BPA and MBzP, but similar during and before pregnancy for MBP, MEP, and ΣDEHP. During pregnancy, MEP (ICC = 0.50) and MBP (ICC = 0.45) were less variable than BPA (ICC = 0.12), MBzP (ICC = 0.25), and ΣDEHP metabolites (ICC = 0.08). Surrogate analyses suggested that a single spot urine sample may reasonably classify MEP and MBP concentrations during pregnancy, but more than one sample may be necessary for MBzP, DEHP, and BPA. Conclusions: Urinary phthalate metabolites and BPA concentrations were variable before and during pregnancy, but the magnitude of variability was biomarker specific. A single spot urine sample

  13. Visualization of single-wall carbon nanotube (SWNT) networks in conductive polystyrene nanocomposites by charge contrast imaging

    International Nuclear Information System (INIS)

    Loos, Joachim; Alexeev, Alexander; Grossiord, Nadia; Koning, Cor E.; Regev, Oren

    2005-01-01

    The morphology of conductive nanocomposites consisting of low concentration of single-wall carbon nanotubes (SWNT) and polystyrene (PS) has been studied using atomic force microscopy (AFM), transmission electron microscopy (TEM) and, in particular, scanning electron microscopy (SEM). Application of charge contrast imaging in SEM allows visualization of the overall SWNT dispersion within the polymer matrix as well as the identification of individual or bundled SWNTs at high resolution. The contrast mechanism involved will be discussed. In conductive nanocomposites the SWNTs are homogeneously dispersed within the polymer matrix and form a network. Beside fairly straight SWNTs, strongly bended SWNTs have been observed. However, for samples with SWNT concentrations below the percolation threshold, the common overall charging behavior of an insulating material is observed preventing the detailed morphological investigation of the sample

  14. Decay dynamics of neutral and charged excitonic complexes in single InAs/GaAs QDs

    International Nuclear Information System (INIS)

    Feucker, Max; Seguin, Robert; Rodt, Sven; Poetschke, Konstantin; Bimberg, Dieter

    2008-01-01

    Across the inhomogeneously broadened lineshape of a quantum dot (QD) ensemble the decay times are expected to vary since the wavefunctions and the oscillator strengths are sensitive to the actual geometry of the QD. We performed time-resolved cathodoluminescence spectroscopy of 26 different single InAs/GaAs QDs to investigate the decay dynamics of neutral and charged excitonic complexes. The largest decay rate was found for the XX + , followed by XX, X + and finally the X. We will show that the ratios of lifetimes of the different excitonic complexes are mainly governed by the number of involved recombination channels. There is excellent agreement between the measured and predicted values for the lifetime ratios of the neutral (X/XX) and the positively charged (X + /XX + ) complexes. Surprisingly the lifetime of the exciton (X) shows a much larger yet unexplained scatter than that of all the other complexes

  15. Single helically folded aromatic oligoamides that mimic the charge surface of double-stranded B-DNA

    Science.gov (United States)

    Ziach, Krzysztof; Chollet, Céline; Parissi, Vincent; Prabhakaran, Panchami; Marchivie, Mathieu; Corvaglia, Valentina; Bose, Partha Pratim; Laxmi-Reddy, Katta; Godde, Frédéric; Schmitter, Jean-Marie; Chaignepain, Stéphane; Pourquier, Philippe; Huc, Ivan

    2018-05-01

    Numerous essential biomolecular processes require the recognition of DNA surface features by proteins. Molecules mimicking these features could potentially act as decoys and interfere with pharmacologically or therapeutically relevant protein-DNA interactions. Although naturally occurring DNA-mimicking proteins have been described, synthetic tunable molecules that mimic the charge surface of double-stranded DNA are not known. Here, we report the design, synthesis and structural characterization of aromatic oligoamides that fold into single helical conformations and display a double helical array of negatively charged residues in positions that match the phosphate moieties in B-DNA. These molecules were able to inhibit several enzymes possessing non-sequence-selective DNA-binding properties, including topoisomerase 1 and HIV-1 integrase, presumably through specific foldamer-protein interactions, whereas sequence-selective enzymes were not inhibited. Such modular and synthetically accessible DNA mimics provide a versatile platform to design novel inhibitors of protein-DNA interactions.

  16. Charging a Capacitor from an External Fluctuating Potential using a Single Conical Nanopore

    Science.gov (United States)

    Gomez, Vicente; Ramirez, Patricio; Cervera, Javier; Nasir, Saima; Ali, Mubarak; Ensinger, Wolfgang; Mafe, Salvador

    2015-01-01

    We explore the electrical rectification of large amplitude fluctuating signals by an asymmetric nanostructure operating in aqueous solution. We show experimentally and theoretically that a load capacitor can be charged to voltages close to 1 V within a few minutes by converting zero time-average potentials of amplitudes in the range 0.5–3 V into average net currents using a single conical nanopore. This process suggests that significant energy conversion and storage from an electrically fluctuating environment is feasible with a nanoscale pore immersed in a liquid electrolyte solution, a system characteristic of bioelectronics interfaces, electrochemical cells, and nanoporous membranes. PMID:25830563

  17. A new paradigm for known metabolite identification in metabonomics/metabolomics: metabolite identification efficiency.

    Science.gov (United States)

    Everett, Jeremy R

    2015-01-01

    A new paradigm is proposed for assessing confidence in the identification of known metabolites in metabonomics studies using NMR spectroscopy approaches. This new paradigm is based upon the analysis of the amount of metabolite identification information retrieved from NMR spectra relative to the molecular size of the metabolite. Several new indices are proposed including: metabolite identification efficiency (MIE) and metabolite identification carbon efficiency (MICE), both of which can be easily calculated. These indices, together with some guidelines, can be used to provide a better indication of known metabolite identification confidence in metabonomics studies than existing methods. Since known metabolite identification in untargeted metabonomics studies is one of the key bottlenecks facing the science currently, it is hoped that these concepts based on molecular spectroscopic informatics, will find utility in the field.

  18. A New Paradigm for Known Metabolite Identification in Metabonomics/Metabolomics: Metabolite Identification Efficiency

    Directory of Open Access Journals (Sweden)

    Jeremy R. Everett

    2015-01-01

    Full Text Available A new paradigm is proposed for assessing confidence in the identification of known metabolites in metabonomics studies using NMR spectroscopy approaches. This new paradigm is based upon the analysis of the amount of metabolite identification information retrieved from NMR spectra relative to the molecular size of the metabolite. Several new indices are proposed including: metabolite identification efficiency (MIE and metabolite identification carbon efficiency (MICE, both of which can be easily calculated. These indices, together with some guidelines, can be used to provide a better indication of known metabolite identification confidence in metabonomics studies than existing methods. Since known metabolite identification in untargeted metabonomics studies is one of the key bottlenecks facing the science currently, it is hoped that these concepts based on molecular spectroscopic informatics, will find utility in the field.

  19. Metabolite profiling of microfluidic cell culture conditions for droplet based screening

    DEFF Research Database (Denmark)

    Björk, Sara M.; Sjoström, Staffan L.; Svahn, Helene Andersson

    2015-01-01

    We investigate the impact of droplet culture conditions on cell metabolic state by determining key metabolite concentrations in S. cerevisiae cultures in different microfluidic droplet culture formats. Control of culture conditions is critical for single cell/clone screening in droplets......, such as directed evolution of yeast, as cell metabolic state directly affects production yields from cell factories. Here, we analyze glucose, pyruvate, ethanol, and glycerol, central metabolites in yeast glucose dissimilation to establish culture formats for screening of respiring as well as fermenting yeast...... limited cultures, whereas the metabolite profiles of cells cultured in the alternative wide tube droplet incubation format resemble those from aerobic culture. Furthermore, we demonstrate retained droplet stability and size in the new better oxygenated droplet incubation format....

  20. The effects of two counterpropagating surface acoustic wave beams on single electron acoustic charge transport

    International Nuclear Information System (INIS)

    He Jianhong; Guo Huazhong; Song Li; Zhang Wei; Gao Jie; Lu Chuan

    2010-01-01

    We present a comprehensive study of the effects of two counterpropagating surface acoustic waves on the acoustoelectric current of single electron transport devices. A significant improvement in the accuracy of current quantization is achieved as a result of an additional surface acoustic wave beam. The experiments reveal the sinusoidally periodical modulation in the acoustoelectric current characteristic as a function of the relative phase of the two surface acoustic wave beams. Besides, by using standing surface acoustic waves, the acoustoelectric current is detected which we consider as the so-called anomalous acoustoelectric current produced by acoustic wave mechanical deformations. This kind current is contributed to one component of the acoustoelectric current in surface acoustic wave device, which could enable us to establish a more adequate description of acoustoelectric effects on single-electron acoustic charge transport.

  1. Flagella-Driven Flows Circumvent Diffusive Bottlenecks that Inhibit Metabolite Exchange

    Science.gov (United States)

    Short, Martin; Solari, Cristian; Ganguly, Sujoy; Kessler, John; Goldstein, Raymond; Powers, Thomas

    2006-03-01

    The evolution of single cells to large and multicellular organisms requires matching the organisms' needs to the rate of exchange of metabolites with the environment. This logistic problem can be a severe constraint on development. For organisms with a body plan that approximates a spherical shell, such as colonies of the volvocine green algae, the required current of metabolites grows quadratically with colony radius whereas the rate at which diffusion can exchange metabolites grows only linearly with radius. Hence, there is a bottleneck radius beyond which the diffusive current cannot keep up with metabolic demands. Using Volvox carteri as a model organism, we examine experimentally and theoretically the role that advection of fluid by surface-mounted flagella plays in enhancing nutrient uptake. We show that fluid flow driven by the coordinated beating of flagella produces a convective boundary layer in the concentration of a diffusing solute which in turn renders the metabolite exchange rate quadratic in the colony radius. This enhanced transport circumvents the diffusive bottleneck, allowing increase in size and thus evolutionary transitions to multicellularity in the Volvocales.

  2. Development of a Charged Particle Microbeam for Single-Particle Subcellular Irradiations at the MIT Laboratory for Accelerator Beam Application

    International Nuclear Information System (INIS)

    Yanch, Jacquelyn C.

    2004-01-01

    The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube

  3. Differentiation-Dependent Energy Production and Metabolite Utilization: A Comparative Study on Neural Stem Cells, Neurons, and Astrocytes

    Science.gov (United States)

    Jády, Attila Gy.; Nagy, Ádám M.; Kőhidi, Tímea; Ferenczi, Szilamér; Tretter, László

    2016-01-01

    While it is evident that the metabolic machinery of stem cells should be fairly different from that of differentiated neurons, the basic energy production pathways in neural stem cells (NSCs) or in neurons are far from clear. Using the model of in vitro neuron production by NE-4C NSCs, this study focused on the metabolic changes taking place during the in vitro neuronal differentiation. O2 consumption, H+ production, and metabolic responses to single metabolites were measured in cultures of NSCs and in their neuronal derivatives, as well as in primary neuronal and astroglial cultures. In metabolite-free solutions, NSCs consumed little O2 and displayed a higher level of mitochondrial proton leak than neurons. In stem cells, glycolysis was the main source of energy for the survival of a 2.5-h period of metabolite deprivation. In contrast, stem cell-derived or primary neurons sustained a high-level oxidative phosphorylation during metabolite deprivation, indicating the consumption of own cellular material for energy production. The stem cells increased O2 consumption and mitochondrial ATP production in response to single metabolites (with the exception of glucose), showing rapid adaptation of the metabolic machinery to the available resources. In contrast, single metabolites did not increase the O2 consumption of neurons or astrocytes. In “starving” neurons, neither lactate nor pyruvate was utilized for mitochondrial ATP production. Gene expression studies also suggested that aerobic glycolysis and rapid metabolic adaptation characterize the NE-4C NSCs, while autophagy and alternative glucose utilization play important roles in the metabolism of stem cell-derived neurons. PMID:27116891

  4. Charge exchange in slow collisions of multiply charged ions with atoms

    International Nuclear Information System (INIS)

    Presnyakov, L.P.; Uskov, D.B.; Janev, R.K.

    1982-01-01

    Single-electron charge exchange between ions having a charge Z>6 and atoms is considered at relative velocities v< Z/sup 1/2/. An analytic method is developed for the solution of a multilevel problem that is a generalization of the decay model and of the approximation of nonadiabatic coupling between two states. Expressions are obtained for the reaction-product distributions in the principal and angular quantum numbers. The calculated total cross sections agree well with the experimental data on charge exchange of hydrogen atoms and molecules with nuclei. The theory describes the oscillations of the total cross section against the background of a monotonic growth as the charge is increased

  5. Single neutral pion production by charged-current ν¯μ interactions on hydrocarbon at 〈Eν〉=3.6 GeV

    Directory of Open Access Journals (Sweden)

    T. Le

    2015-10-01

    Full Text Available Single neutral pion production via muon antineutrino charged-current interactions in plastic scintillator (CH is studied using the MINERvA detector exposed to the NuMI low-energy, wideband antineutrino beam at Fermilab. Measurement of this process constrains models of neutral pion production in nuclei, which is important because the neutral-current analog is a background for ν¯e appearance oscillation experiments. The differential cross sections for π0 momentum and production angle, for events with a single observed π0 and no charged pions, are presented and compared to model predictions. These results comprise the first measurement of the π0 kinematics for this process.

  6. Tissue distribution of 14C-diazepam and its metabolites in rats

    International Nuclear Information System (INIS)

    Igari, Y.; Sugiyama, Y.; Sawada, Y.; Iga, T.; Hanano, M.

    1982-01-01

    We have kinetically investigated the tissue distribution of 14 C-diazepam and described the appearance and disappearance of its metabolites (3-hydroxydiazepam, desmethyldiazepam, and oxazepam) following a single iv injection of 14 C-diazepam into rats. Significant amounts of oxazepam were detected in plasma and various tissues in the rat, contrary to previous reports. Concentration-time profiles of diazepam in the main disposing organs (liver, kidney, and lung) and the other organs (brain, heart, and small intestine) indicated that diazepam was distributed rapidly to these organs. Concentration-time profiles of diazepam in the main tissues for drug distribution (skin and adipose) indicated that diazepam was slowly distributed to these tissues, whereas that in muscle, which is also responsible for drug distribution, indicated that diazepam was less rapidly distributed to this tissue. Metabolites appeared in plasma and various tissues or organs immediately after iv injection of diazepam. Metabolites levels in plasma and various tissues or organs were significantly lower than that of diazepam except for liver and small intestine, where metabolites levels were higher compared to that of diazepam and metabolites exhibited a considerable persistence

  7. Thermodynamics-based Metabolite Sensitivity Analysis in metabolic networks.

    Science.gov (United States)

    Kiparissides, A; Hatzimanikatis, V

    2017-01-01

    The increasing availability of large metabolomics datasets enhances the need for computational methodologies that can organize the data in a way that can lead to the inference of meaningful relationships. Knowledge of the metabolic state of a cell and how it responds to various stimuli and extracellular conditions can offer significant insight in the regulatory functions and how to manipulate them. Constraint based methods, such as Flux Balance Analysis (FBA) and Thermodynamics-based flux analysis (TFA), are commonly used to estimate the flow of metabolites through genome-wide metabolic networks, making it possible to identify the ranges of flux values that are consistent with the studied physiological and thermodynamic conditions. However, unless key intracellular fluxes and metabolite concentrations are known, constraint-based models lead to underdetermined problem formulations. This lack of information propagates as uncertainty in the estimation of fluxes and basic reaction properties such as the determination of reaction directionalities. Therefore, knowledge of which metabolites, if measured, would contribute the most to reducing this uncertainty can significantly improve our ability to define the internal state of the cell. In the present work we combine constraint based modeling, Design of Experiments (DoE) and Global Sensitivity Analysis (GSA) into the Thermodynamics-based Metabolite Sensitivity Analysis (TMSA) method. TMSA ranks metabolites comprising a metabolic network based on their ability to constrain the gamut of possible solutions to a limited, thermodynamically consistent set of internal states. TMSA is modular and can be applied to a single reaction, a metabolic pathway or an entire metabolic network. This is, to our knowledge, the first attempt to use metabolic modeling in order to provide a significance ranking of metabolites to guide experimental measurements. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier

  8. Investigation of the charge-orbital ordering mechanism in single-layered Pr0.5Ca1.5MnO4

    Science.gov (United States)

    Rangkuti, C. N.; Majidi, M. A.

    2018-04-01

    Motivated by the experimental study of half-doped single-layered Pr0.5Ca1.5MnO4 showing charge, orbital, and spin orderings [1], we propose a model to theoretically study the system to explain such ordering phenomena. The ground state electron configuration reveals that the charges form a checkerboard pattern with alternating Mn3+/Mn4+ sites, while the orbitals are aligned in zigzag chains [1, 2]. We calculate the ground state energy of this system to find the most preferable configuration by comparing three types of configurations (charge-unordered, charge-ordered, and charge-orbital-ordered states). The calculations are based on a tight-binding model representing effective electron hoppings among Mn ions in MnO2-plane. We take into account the horizontally- and vertically-oriented orbital and spin degrees of freedom at Mn sites. We assume that the hopping integral values depend on the relative orientation between the corresponding orbitals of adjacent Mn ions. The interaction terms we incorporate into our effective Hamiltonian include inter-orbital, intra-orbital Hubbard repulsions, and Jahn-Teller distortion [2]. We absorb the exchange interaction between spins into local self-energy that we calculate within dynamical mean field algorithm [2]. Within our model we show a circumstance in which the charge-orbital ordered configuration has the lowest energy, consistent with the ground state ordering revealed by the experimental data.

  9. PHARMACOKINETICS OF TRAMADOL HYDROCHLORIDE AND ITS METABOLITE O-DESMETHYLTRAMADOL FOLLOWING A SINGLE, ORALLY ADMINISTERED DOSE IN CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS).

    Science.gov (United States)

    Boonstra, Jennifer L; Barbosa, Lorraine; Van Bonn, William G; Johnson, Shawn P; Gulland, Frances M D; Cox, Sherry K; Martin-Jimenez, Tomas

    2015-09-01

    Tramadol is a synthetic, centrally acting, opiate-like analgesic that is structurally related to codeine and morphine. The objective of this study was to determine the pharmacokinetics of tramadol hydrochloride and its major active metabolite O-desmethyltramadol (M1) in the California sea lion (Zalophus californianus). A single dose of tramadol was administered orally in fish at 2 mg/kg to a total of 15 wild California sea lions admitted for rehabilitation. Twenty-four total blood samples were collected post drug administration at 10, 20, 30, and 45 min and at 1, 3, 5, 6, 8, 12, and 24 hr. Blood plasma was separated and stored at -80°C until analysis with high-performance liquid chromatography was performed to determine levels of tramadol and M1, the major active metabolite. The results indicate that the plasma levels of parent tramadol are low or negligible during the first 30-45 min and then reach the predicted mean maximum plasma concentration of 358 ng/ml at 1.52 hr. The M1 metabolite was not detectable in 21 of 24 plasma samples, below the level of quantification of 5 ng/ml in one sample, and detectable at 11 and 17 ng/ml in two of the samples. This study suggests that a 2 mg/kg dose would need to be administered every 6-8 hr to maintain concentrations of tramadol above the minimum human analgesic level for mild to moderate pain. Based on dosing simulations, a dose of 4 mg/kg q8 hr or q12 hr, on average, may represent an adequate compromise, but further studies are needed using a larger sample size. Pharmacodynamic studies are warranted to determine if tramadol provides analgesic effects in this species. The potential for tramadol toxicosis at any dose also has not been determined in this species.

  10. Single-electron charging effects

    International Nuclear Information System (INIS)

    Ruggiero, S.T.

    1991-01-01

    The status of our project on single-electron tunneling is, again, excellent. As outlined in our original proposal, a key goal for this project has been the development of a scanning tunneling instrument for the purpose of imaging individual particles and tunneling into these particles at high magnetic fields. Further progress is discussed in this report

  11. Counter-ions at single charged wall: Sum rules.

    Science.gov (United States)

    Samaj, Ladislav

    2013-09-01

    For inhomogeneous classical Coulomb fluids in thermal equilibrium, like the jellium or the two-component Coulomb gas, there exists a variety of exact sum rules which relate the particle one-body and two-body densities. The necessary condition for these sum rules is that the Coulomb fluid possesses good screening properties, i.e. the particle correlation functions or the averaged charge inhomogeneity, say close to a wall, exhibit a short-range (usually exponential) decay. In this work, we study equilibrium statistical mechanics of an electric double layer with counter-ions only, i.e. a globally neutral system of equally charged point-like particles in the vicinity of a plain hard wall carrying a fixed uniform surface charge density of opposite sign. At large distances from the wall, the one-body and two-body counter-ion densities go to zero slowly according to the inverse-power law. In spite of the absence of screening, all known sum rules are shown to hold for two exactly solvable cases of the present system: in the weak-coupling Poisson-Boltzmann limit (in any spatial dimension larger than one) and at a special free-fermion coupling constant in two dimensions. This fact indicates an extended validity of the sum rules and provides a consistency check for reasonable theoretical approaches.

  12. Design and simulation of ion optics for ion sources for production of singly charged ions

    Science.gov (United States)

    Zelenak, A.; Bogomolov, S. L.

    2004-05-01

    During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments.

  13. Design and simulation of ion optics for ion sources for production of singly charged ions

    International Nuclear Information System (INIS)

    Zelenak, A.; Bogomolov, S.L.

    2004-01-01

    During the last 2 years different types of the singly charged ion sources were developed for FLNR (JINR) new projects such as Dubna radioactive ion beams, (Phase I and Phase II), the production of the tritium ion beam and the MASHA mass separator. The ion optics simulations for 2.45 GHz electron cyclotron resonance source, rf source, and the plasma ion source were performed. In this article the design and simulation results of the optics of new ion sources are presented. The results of simulation are compared with measurements obtained during the experiments

  14. Detection of 191 Taxifolin Metabolites and Their Distribution in Rats Using HPLC-ESI-IT-TOF-MSn

    Directory of Open Access Journals (Sweden)

    Ping Yang

    2016-09-01

    Full Text Available Taxifolin is a ubiquitous bioactive constituent of foods and herbs. To thoroughly explore its metabolism in vivo, an HPLC-ESI-IT-TOF-MSn method combined with specific metabolite detection strategy was used to detect and identify the metabolites of taxifolin in rats. Of the 191 metabolites tentatively identified, 154 were new metabolites, 69 were new compounds and 32 were dimers. This is the first report of the in vivo biotransformation of a single compound into more than 100 metabolites. Furthermore, acetylamination and pyroglutamic acid conjugation were identified as new metabolic reactions. Seventeen metabolites were found to have various taxifolin-related bioactivities. The potential targets of taxifolin and 63 metabolites were predicted using PharmMapper, with results showing that more than 60 metabolites have the same five targets. Metabolites with the same fragment pattern may have the same pharmacophore. Thus these metabolites may exert the same pharmacological effects as taxifolin through an additive effect on the same drug targets. This observation indicates that taxifolin is bioactive not only in the parent form, but also through its metabolites. These findings enhance understanding of the metabolism and effective forms of taxifolin and may provide further insight of the beneficial effects of taxifolin and its derivatives.

  15. Enantioseparation of thalidomide and its hydroxylated metabolites using capillary electrophoresis with various cyclodextrins and their combinations as chiral buffer additives.

    Science.gov (United States)

    Meyring, M; Chankvetadze, B; Blaschke, G

    1999-09-01

    The separation of thalidomide (TD) and its hydroxylated metabolites including their simultaneous enantioseparation was studied in capillary electrophoresis (CE) using four different randomly substituted charged cyclodextrin (CD) derivatives, the combinations of some of them with each other, and beta-CD. TD, as well as two metabolites recently found in incubations of human liver microsomes and human blood, 5-hydroxythalidomide (5-OH-TD) and one of the diastereomeric 5'-hydroxythalidomides (5'-OH-TD), are neutral compounds. Therefore, they were resolved using charged chiral selectors in CE. Two different separation modes (normal polarity and carrier mode) and two different capillaries (fused-silica and polyacrylamide-coated) were tested. Based on the behavior of the individual CDs, their designed combinations were selected in order to improve the separation selectivity and enantioselectivity. Under optimized conditions all three chiral compounds and their enantiomers were resolved simultaneously.

  16. Pyramidal pits created by single highly charged ions in BaF2 single crystals

    International Nuclear Information System (INIS)

    El-Said, A. S.; Heller, R.; Facsko, S.; Aumayr, F.

    2010-01-01

    In various insulators, the impact of individual slow highly charged ions (eV-keV) creates surface nanostructures, whose size depends on the deposited potential energy. Here we report on the damage created on a cleaved BaF 2 (111) surface by irradiation with 4.5xq keV highly charged xenon ions from a room-temperature electron-beam ion trap. Up to charge states q=36, no surface topographic changes on the BaF 2 surface are observed by scanning force microscopy. The hidden stored damage, however, can be made visible using the technique of selective chemical etching. Each individual ion impact develops into a pyramidal etch pits, as can be concluded from a comparison of the areal density of observed etch pits with the applied ion fluence (typically 10 8 ions/cm 2 ). The dimensional analysis of the measured pits reveals the significance of the deposited potential energy in the creation of lattice distortions/defects in BaF 2 .

  17. Charge distribution in an two-chain dual model

    International Nuclear Information System (INIS)

    Fialkowski, K.; Kotanski, A.

    1983-01-01

    Charge distributions in the multiple production processes are analysed using the dual chain model. A parametrisation of charge distributions for single dual chains based on the νp and anti vp data is proposed. The rapidity charge distributions are then calculated for pp and anti pp collisions and compared with the previous calculations based on the recursive cascade model of single chains. The results differ at the SPS collider energies and in the energy dependence of the net forward charge supplying the useful tests of the dual chain model. (orig.)

  18. Long-Lived Charge Separation at Heterojunctions between Semiconducting Single-Walled Carbon Nanotubes and Perylene Diimide Electron Acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyun Suk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Arias, Dylan H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Blackburn, Jeffrey L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sisto, Thomas J. [Columbia University; Peurifoy, Samuel [Columbia University; Zhang, Boyuan [Columbia University; Nuckolls, Colin [Columbia University

    2018-04-13

    Nonfullerene electron acceptors have facilitated a recent surge in the efficiencies of organic solar cells, although fundamental studies of the nature of exciton dissociation at interfaces with nonfullerene electron acceptors are still relatively sparse. Semiconducting single-walled carbon nanotubes (s-SWCNTs), unique one-dimensional electron donors with molecule-like absorption and highly mobile charges, provide a model system for studying interfacial exciton dissociation. Here, we investigate excited-state photodynamics at the heterojunction between (6,5) s-SWCNTs and two perylene diimide (PDI)-based electron acceptors. Each of the PDI-based acceptors, hPDI2-pyr-hPDI2 and Trip-hPDI2, is deposited onto (6,5) s-SWCNT films to form a heterojunction bilayer. Transient absorption measurements demonstrate that photoinduced hole/electron transfer occurs at the photoexcited bilayer interfaces, producing long-lived separated charges with lifetimes exceeding 1.0 us. Both exciton dissociation and charge recombination occur more slowly for the hPDI2-pyr-hPDI2 bilayer than for the Trip-hPDI2 bilayer. To explain such differences, we discuss the potential roles of the thermodynamic charge transfer driving force available at each interface and the different molecular structure and intermolecular interactions of PDI-based acceptors. Detailed photophysical analysis of these model systems can develop the fundamental understanding of exciton dissociation between organic electron donors and nonfullerene acceptors, which has not been systematically studied.

  19. Interactions among filamentous fungi Aspergillus niger, Fusarium verticillioides and Clonostachys rosea: fungal biomass, diversity of secreted metabolites and fumonisin production.

    Science.gov (United States)

    Chatterjee, Subhankar; Kuang, Yi; Splivallo, Richard; Chatterjee, Paramita; Karlovsky, Petr

    2016-05-10

    Interactions among fungi colonizing dead organic matter involve exploitation competition and interference competition. Major mechanism of interference competition is antibiosis caused by secreted secondary metabolites. The effect of competition on secondary metabolite production by fungi is however poorly understood. Fungal biomass was rarely monitored in interaction studies; it is not known whether dominance in pairwise interactions follows congruent patterns. Pairwise interactions of three fungal species with different life styles were studied. The saprophyte Aspergillus niger (A.n.), the plant pathogen Fusarium verticillioides (F.v.), and the mycoparasite Clonostachys rosea (C.r.) were grown in single and dual cultures in minimal medium with asparagine as nitrogen source. Competitive fitness shifted with time: in dual C.r./F.v. cultures after 10 d F.v. grew well while C.r. was suppressed; after 20 d C.r. recovered while F.v. became suppressed; and after 30 d most F.v. was destroyed. At certain time points fungal competitive fitness exhibited a rock-paper-scissors pattern: F.v. > A.n., A.n. > C.r., and C.r. > F.v. Most metabolites secreted to the medium at early stages in single and dual cultures were not found at later times. Many metabolites occurring in supernatants of single cultures were suppressed in dual cultures and many new metabolites not occurring in single cultures were found in dual cultures. A. niger showed the greatest ability to suppress the accumulation of metabolites produced by the other fungi. A. niger was also the species with the largest capacity of transforming metabolites produced by other fungi. Fumonisin production by F. verticillioides was suppressed in co-cultures with C. rosea but fumonisin B1 was not degraded by C. rosea nor did it affect the growth of C. rosea up to a concentration of 160 μg/ml. Competitive fitness in pairwise interactions among fungi is incongruent, indicating that species-specific factors and/or effects are

  20. Charge Transport in Spiro-OMeTAD Investigated through Space-Charge-Limited Current Measurements

    Science.gov (United States)

    Röhr, Jason A.; Shi, Xingyuan; Haque, Saif A.; Kirchartz, Thomas; Nelson, Jenny

    2018-04-01

    Extracting charge-carrier mobilities for organic semiconductors from space-charge-limited conduction measurements is complicated in practice by nonideal factors such as trapping in defects and injection barriers. Here, we show that by allowing the bandlike charge-carrier mobility, trap characteristics, injection barrier heights, and the shunt resistance to vary in a multiple-trapping drift-diffusion model, a numerical fit can be obtained to the entire current density-voltage curve from experimental space-charge-limited current measurements on both symmetric and asymmetric 2 ,2',7 ,7' -tetrakis(N ,N -di-4-methoxyphenylamine)-9 ,9' -spirobifluorene (spiro-OMeTAD) single-carrier devices. This approach yields a bandlike mobility that is more than an order of magnitude higher than the effective mobility obtained using analytical approximations, such as the Mott-Gurney law and the moving-electrode equation. It is also shown that where these analytical approximations require a temperature-dependent effective mobility to achieve fits, the numerical model can yield a temperature-, electric-field-, and charge-carrier-density-independent mobility. Finally, we present an analytical model describing trap-limited current flow through a semiconductor in a symmetric single-carrier device. We compare the obtained charge-carrier mobility and trap characteristics from this analytical model to the results from the numerical model, showing excellent agreement. This work shows the importance of accounting for traps and injection barriers explicitly when analyzing current density-voltage curves from space-charge-limited current measurements.

  1. Evaluation of the genotoxic potential of 3-monochloropropane-1,2-diol (3-MCPD) and its metabolites, glycidol and beta-chlorolactic acid, using the single cell gel/comet assay.

    Science.gov (United States)

    El Ramy, R; Ould Elhkim, M; Lezmi, S; Poul, J M

    2007-01-01

    3-monochloropropane-1,2-diol (3-MCPD) is a member of a group of chemicals known as chloropropanols. It is found in many foods and food ingredients as a result of food processing. 3-MCPD is regarded as a rat carcinogen known to induce Leydig-cell and mammary gland tumours in males and kidney tumours in both genders. The aim of our study was to clarify the possible involvement of genotoxic mechanisms in 3-MCPD induced carcinogenicity at the target organ level. For that purpose, we evaluated DNA damages in selected target (kidneys and testes) and non-target (blood leukocytes, liver and bone marrow) male rat organs by the in vivo alkaline single cell gel electrophoresis (comet) assay, 3 and 24 h after 3-MCPD oral administration to Sprague-Dawley and Fisher 344 adult rats. 3-MCPD may be metabolised to a genotoxic intermediate, glycidol, whereas the predominant urinary metabolite in rats following 3-MCPD administration is beta-chlorolactic acid. Therefore, we also studied the DNA damaging effects of 3-MCPD and its metabolites, glycidol and beta-chlorolactic acid, in the in vitro comet assay on CHO cells. Our results show the absence of genotoxic potential of 3-MCPD in vivo in the target as well as in the non-target organs. Glycidol, the epoxide metabolite, induced DNA damages in CHO cells. beta-Chlorolactic acid, the main metabolite of 3-MCPD in rats, was shown to be devoid of DNA-damaging effects in vitro in mammalian cells.

  2. Study of the Bulk Charge Carrier Dynamics in Anatase and Rutile TiO2 Single Crystals by Femtosecond Time Resolved Spectroscopy

    KAUST Repository

    Maity, Partha; Mohammed, Omar F.; Katsiev, Khabiboulakh; Idriss, Hicham

    2018-01-01

    as the best model for fundamental studies. Their ultrafast charge carrier dynamics especially on TiO2 anatase single crystal (the most active phase) are unresolved. Here femtosecond time resolved spectroscopy (TRS) was carried out to explore the dynamics

  3. Complicating factors in safety testing of drug metabolites: Kinetic differences between generated and preformed metabolites

    International Nuclear Information System (INIS)

    Prueksaritanont, Thomayant; Lin, Jiunn H.; Baillie, Thomas A.

    2006-01-01

    This paper aims to provide a scientifically based perspective on issues surrounding the proposed toxicology testing of synthetic drug metabolites as a means of ensuring adequate nonclinical safety evaluation of drug candidates that generate metabolites considered either to be unique to humans or are present at much higher levels in humans than in preclinical species. We put forward a number of theoretical considerations and present several specific examples where the kinetic behavior of a preformed metabolite given to animals or humans differs from that of the corresponding metabolite generated endogenously from its parent. The potential ramifications of this phenomenon are that the results of toxicity testing of the preformed metabolite may be misleading and fail to characterize the true toxicological contribution of the metabolite when formed from the parent. It is anticipated that such complications would be evident in situations where (a) differences exist in the accumulation of the preformed versus generated metabolites in specific tissues, and (b) the metabolite undergoes sequential metabolism to a downstream product that is toxic, leading to differences in tissue-specific toxicity. Owing to the complex nature of this subject, there is a need to treat drug metabolite issues in safety assessment on a case-by-case basis, in which a knowledge of metabolite kinetics is employed to validate experimental paradigms that entail administration of preformed metabolites to animal models

  4. Effect of quenched disorder on charge-orbital-spin ordering in single-layer manganites

    International Nuclear Information System (INIS)

    Uchida, Masaya; Mathieu, Roland; He, Jinping; Kaneko, Yoshio; Tokura, Yoshinori; Asamitsu, Atsushi; Kumai, Reiji; Tomioka, Yasuhide; Matsui, Yoshio

    2006-01-01

    Structural and magnetic properties have been investigated for half-doped single-layer manganites RE 0.5 Sr 1.5 MnO 4 [RE=La, (La, Pr), Pr, Nd, Sm, and Eu]. Analyses of electron diffraction and ac susceptibility measurements have revealed that the long-range charge-orbital ordering (CO-OO) state as observed in La 0.5 Sr 1.5 MnO 4 is suppressed for the other materials: the CO-OO transition temperature, as well as the correlation length decreases with a decrease in the cation size of RE. Such a short-range CO-OO state shows a spin-glass behavior at low temperatures. A new electronic phase diagram is established with quenched disorder as the control parameter. (author)

  5. Transverse target single-spin asymmetry in inclusive electroproduction of charged pions and kaons

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Giessen Univ. (Germany). 2. Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Laboratory of Physics; Akopov, N. [Yerevan Physics Institute (Argentina); Akopov, Z. [DESY Hamburg (Germany)] [and others; Collaboration: HERMES Collaboration

    2013-10-15

    Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle {psi} about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum P{sub T} relative to the direction of the incident beam, and the Feynman variable x{sub F}. The sin {psi} amplitudes are positive for {pi}{sup +} and K{sup +}, slightly negative for {pi}{sup -} consistent with zero for K{sup -}, with particular P{sub T} but weak x{sub F} dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer.

  6. "3"1P Nuclear Magnetic Resonance of Charge-Density-Wave Transition in a Single Crystal of RuP

    International Nuclear Information System (INIS)

    Fan Guo-Zhi; Luo Jian-Lin; Chen Rong-Yan; Wang Nan-Lin

    2015-01-01

    We perform "3"1P nuclear magnetic resonance (NMR) measurements on a single crystal of RuP. The anomalies in resistivity at about T_A = 270 K and T_B = 330 K indicate that two phase transitions occur. The line shape of "3"1P NMR spectra in different temperature ranges is attributed to the charge density distribution. The Knight shift and spin-lattice relaxation rate 1/T_1T are measured from 10 K to 300 K. At about T_A = 270 K, they both decrease abruptly with the temperature reduction, which reveals the gap-opening behavior. Well below T_A, they act like the case of normal metal. Charge-density-wave phase transition is proposed to interpret the transition occurring at about T_A. (paper)

  7. Air charged and microtip catheters cannot be used interchangeably for urethral pressure measurement: a prospective, single-blind, randomized trial.

    Science.gov (United States)

    Zehnder, Pascal; Roth, Beat; Burkhard, Fiona C; Kessler, Thomas M

    2008-09-01

    We determined and compared urethral pressure measurements using air charged and microtip catheters in a prospective, single-blind, randomized trial. A consecutive series of 64 women referred for urodynamic investigation underwent sequential urethral pressure measurements using an air charged and a microtip catheter in randomized order. Patients were blinded to the type and sequence of catheter used. Agreement between the 2 catheter systems was assessed using the Bland and Altman 95% limits of agreement method. Intraclass correlation coefficients of air charged and microtip catheters for maximum urethral closure pressure at rest were 0.97 and 0.93, and for functional profile length they were 0.9 and 0.78, respectively. Pearson's correlation coefficients and Lin's concordance coefficients of air charged and microtip catheters were r = 0.82 and rho = 0.79 for maximum urethral closure pressure at rest, and r = 0.73 and rho = 0.7 for functional profile length, respectively. When applying the Bland and Altman method, air charged catheters gave higher readings than microtip catheters for maximum urethral closure pressure at rest (mean difference 7.5 cm H(2)O) and functional profile length (mean difference 1.8 mm). There were wide 95% limits of agreement for differences in maximum urethral closure pressure at rest (-24.1 to 39 cm H(2)O) and functional profile length (-7.7 to 11.3 mm). For urethral pressure measurement the air charged catheter is at least as reliable as the microtip catheter and it generally gives higher readings. However, air charged and microtip catheters cannot be used interchangeably for clinical purposes because of insufficient agreement. Hence, clinicians should be aware that air charged and microtip catheters may yield completely different results, and these differences should be acknowledged during clinical decision making.

  8. Charge distribution of metallic single walled carbon nanotube–graphene junctions

    International Nuclear Information System (INIS)

    Robert, P T; Danneau, R

    2014-01-01

    We report numeric and analytic calculations of the electrostatic properties for armchair carbon nanotube–graphene junctions. Using a semi-empirical method we first demonstrate that the equilibrium distance between a carbon nanotube and a graphene sheet varies with respect to the diameter of the carbon nanotube. We find significantly reduced values compared to AB-stacked graphene sheets in graphite, while even smaller value is found for a fullerene C 60 implying a dimensionality dependence of the equilibrium distance between graphene and the other sp 2 carbon allotropes. Then, we use conformal mapping and a charge–dipole model to study the charge distribution of the carbon nanotube–graphene junctions in various configurations. We observe that the charges are accumulated/depleted at and near the vicinity of the junctions and that capped carbon nanotubes induce a significantly smaller charge concentration at their ends than the open-end nanotubes. We demonstrate that the carbon nanotube influence on the graphene sheet is limited to only few atomic rows. Such an influence strongly depends on the distance between carbon nanotube and the graphene sheet and scales with the carbon nanotube radius, while the potential difference does not modify the length over which the charge concentration is disturbed by the presence of the tube. By studying the potential landscape of carbon nanotube–graphene junctions, our work could be used as a starting point to model the charge carrier injection in these unconventional systems. (paper)

  9. CDW-EIS theoretical calculations of projectile deflection for single ionization in highly charged ion-atom collisions

    International Nuclear Information System (INIS)

    Rodriguez, V.D.

    2003-01-01

    We present continuum distorted wave-eikonal initial state (CDW-EIS) theoretical calculations for the projectile deflection in single ionization of helium by heavy-ion impact as a function of ionized electron energies. These calculations account for the helium passive electron shielding in the internuclear interaction improving standard CDW-EIS theory. The results are compared with recent experimental results by impact of 100 MeV/amu C 6+ and 3.6 MeV/amu Au 53+ . For highly charged projectiles there is a poor quantitative agreement between theory and experiment. However, this refined calculation does share some qualitative features with the data. In particular the variation of the effective charge of the residual He + ion from Z eff =1 to Z eff =2 when going from small to large projectile scattering angles is able to represent a shoulder observed in the double differential cross sections. Important qualitative differences are observed at the level of triple differential cross sections

  10. Tracer kinetic modelling of receptor data with mathematical metabolite correction

    International Nuclear Information System (INIS)

    Burger, C.; Buck, A.

    1996-01-01

    Quantitation of metabolic processes with dynamic positron emission tomography (PET) and tracer kinetic modelling relies on the time course of authentic ligand in plasma, i.e. the input curve. The determination of the latter often requires the measurement of labelled metabilites, a laborious procedure. In this study we examined the possibility of mathematical metabolite correction, which might obviate the need for actual metabolite measurements. Mathematical metabilite correction was implemented by estimating the input curve together with kinetic tissue parameters. The general feasibility of the approach was evaluated in a Monte Carlo simulation using a two tissue compartment model. The method was then applied to a series of five human carbon-11 iomazenil PET studies. The measured cerebral tissue time-activity curves were fitted with a single tissue compartment model. For mathematical metabolite correction the input curve following the peak was approximated by a sum of three decaying exponentials, the amplitudes and characteristic half-times of which were then estimated by the fitting routine. In the simulation study the parameters used to generate synthetic tissue time-activity curves (K 1 -k 4 ) were refitted with reasonable identifiability when using mathematical metabolite correciton. Absolute quantitation of distribution volumes was found to be possible provided that the metabolite and the kinetic models are adequate. If the kinetic model is oversimplified, the linearity of the correlation between true and estimated distribution volumes is still maintained, although the linear regression becomes dependent on the input curve. These simulation results were confirmed when applying mathematical metabolite correction to the 11 C iomazenil study. Estimates of the distribution volume calculated with a measured input curve were linearly related to the estimates calculated using mathematical metabolite correction with correlation coefficients >0.990. (orig./MG)

  11. Search for the Single Production of Doubly-Charged Higgs Bosons and Constraints on their Couplings from Bhabha Scattering

    CERN Document Server

    Abbiendi, G; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Caron, B.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Furtjes, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Groll, M.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harder, K.; Harel, A.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kormos, Laura L.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Leins, A.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, J.; Macpherson, A.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McDonald, W.J.; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schoerner-Sadenius, Thomas; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Siroli, G.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Stephens, K.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Taylor, R.J.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, G.W.; Wilson, D.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

    2003-01-01

    A search for single production of doubly-charged Higgs bosons has been performed using 600.7 pb^-1 of e+e- collision data with sqrt(s)=189--209GeV collected by the OPAL detector at LEP. No evidence for the existence of H++/-- is observed. Upper limits on the Yukawa coupling of the H++/-- to like-signed electron pairs are derived. Additionally, indirect constraints on the Yukawa coupling from Bhabha scattering, where the H++/-- would contribute via t-channel exchange, are derived for M(H++/--) < 2TeV. These are the first results for both a single production search and constraints from Bhabha scattering reported from LEP.

  12. Synthesis and characterization of N-demethylated metabolites of malachite green and leucomalachite green.

    Science.gov (United States)

    Cho, Bongsup P; Yang, Tianle; Blankenship, Lonnie R; Moody, Joanna D; Churchwell, Mona; Beland, Frederick A; Culp, Sandra J

    2003-03-01

    Malachite green (MG), a triphenylmethane dye used to treat fungal and protozoan infections in fish, undergoes sequential oxidation to produce various N-demethylated derivatives (monodes-, dides(sym)-, dides(unsym)-, trides-, and tetrades-) both before and after reduction to leucomalachite green (LMG). The close structure resemblance of the metabolites with aromatic amine carcinogens implicates a potential genotoxicity from exposure to MG. The availability of the synthetic standards is important for metabolic and DNA adduct studies of MG. This paper describes a simple and versatile method for the synthesis of MG, LMG, and their N-demethylated metabolites. The synthesis involves a coupling of 4-(dimethylamino)benzophenone or 4-nitrobenzophenone with the aryllithium reagents derived from appropriately substituted 4-bromoaniline derivatives, followed by treatment with HCl in methanol. The resulting cationic MG and their leuco analogues showed systematic UV/vis spectral and tandem mass fragmentation patterns consistent with sequential N-demethylation. The extensive (1)H and (13)C spectral assignments of the metabolites were aided by the availability of (13)C(7)-labeled MG and LMG. The results indicate the existence of a resonance structure with the cationic charge located in the central methane carbon (C(7)). The synthetic procedure is general in scope so that it can be extended to the preparation of N-demethylated metabolites of other structurally related N-methylated triphenylmethane dyes.

  13. Structure Elucidation of Unknown Metabolites in Metabolomics by Combined NMR and MS/MS Prediction.

    Science.gov (United States)

    Boiteau, Rene M; Hoyt, David W; Nicora, Carrie D; Kinmonth-Schultz, Hannah A; Ward, Joy K; Bingol, Kerem

    2018-01-17

    We introduce a cheminformatics approach that combines highly selective and orthogonal structure elucidation parameters; accurate mass, MS/MS (MS²), and NMR into a single analysis platform to accurately identify unknown metabolites in untargeted studies. The approach starts with an unknown LC-MS feature, and then combines the experimental MS/MS and NMR information of the unknown to effectively filter out the false positive candidate structures based on their predicted MS/MS and NMR spectra. We demonstrate the approach on a model mixture, and then we identify an uncatalogued secondary metabolite in Arabidopsis thaliana . The NMR/MS² approach is well suited to the discovery of new metabolites in plant extracts, microbes, soils, dissolved organic matter, food extracts, biofuels, and biomedical samples, facilitating the identification of metabolites that are not present in experimental NMR and MS metabolomics databases.

  14. Mutagenic azide metabolite is azidoalanine

    International Nuclear Information System (INIS)

    Owais, W.M.; Rosichan, J.L.; Ronald, R.C.; Kleinhofs, A.; Nilan, R.A.

    1981-01-01

    Sodium axide produces high mutation rates in a number of species. Azide mutagenicity is mediated through a metabolite in barley and bacteria. Many studies showed that azide affects the L-cysteine biosynthesis pathway. Cell-free extracts of Salmonella typhimurium convert azide and O-acetylserine to the mutagenic metabolite. O-acetylserine sulfhydrylase was identified as the enzyme responsible for the metabolite biosynthesis. To confirm the conclusion that the azide metabolite is formed through the β-substitution pathway of L-cysteine, we radioactively labeled the azide metabolite using 14 C-labeled precursors. Moreover, the mutagenic azide metabolite was purified and identified as azidoalanine based on mass spectroscopy and elemental analysis. 26 refs., 3 figs., 1 tab

  15. In vivo proton magnetic resonance spectroscopy (1H-MRS) evaluation of the metabolite concentration of optic radiation in primary open angle glaucoma

    Energy Technology Data Exchange (ETDEWEB)

    Sidek, Sabrilhakim [University of Malaya, Department of Biomedical Imaging, University Malaya Research Imaging Centre (UMRIC), Kuala Lumpur (Malaysia); Universiti Teknologi MARA, Medical Imaging Unit, Faculty of Medicine, Sg Buloh, Selangor (Malaysia); Ramli, Norlisah; Rahmat, Kartini; Kuo, Tan Li [University of Malaya, Department of Biomedical Imaging, University Malaya Research Imaging Centre (UMRIC), Kuala Lumpur (Malaysia); Ramli, Norlina Mohd; Abdulrahman, Fadzlina [University of Malaya, Department of Ophthalmology, Faculty of Medicine, Kuala Lumpur (Malaysia)

    2016-12-15

    To compare the metabolite concentration of optic radiation in glaucoma patients with that of healthy subjects using Proton Magnetic Resonance Spectroscopy (1H-MRS). 1H-MRS utilising the Single-Voxel Spectroscopy (SVS) technique was performed using a 3.0Tesla MRI on 45 optic radiations (15 from healthy subjects, 15 from mild glaucoma patients, and 15 from severe glaucoma patients). A standardised Volume of Interest (VOI) of 20 x 20 x 20 mm was placed in the region of optic radiation. Mild and severe glaucoma patients were categorised based on the Hodapp-Parrish-Anderson (HPA) classification. Mean and multiple group comparisons for metabolite concentration and metabolite concentration ratio between glaucoma grades and healthy subjects were obtained using one-way ANOVA. The metabolite concentration and metabolite concentration ratio between the optic radiations of glaucoma patients and healthy subjects did not demonstrate any significant difference (p > 0.05). Our findings show no significant alteration of metabolite concentration associated with neurodegeneration that could be measured by single-voxel 1H-MRS in optic radiation among glaucoma patients. (orig.)

  16. Metabolites in Blood for Prediction of Bacteremic Sepsis in the Emergency Room.

    Directory of Open Access Journals (Sweden)

    Anna M Kauppi

    Full Text Available A metabolomics approach for prediction of bacteremic sepsis in patients in the emergency room (ER was investigated. In a prospective study, whole blood samples from 65 patients with bacteremic sepsis and 49 ER controls were compared. The blood samples were analyzed using gas chromatography coupled to time-of-flight mass spectrometry. Multivariate and logistic regression modeling using metabolites identified by chromatography or using conventional laboratory parameters and clinical scores of infection were employed. A predictive model of bacteremic sepsis with 107 metabolites was developed and validated. The number of metabolites was reduced stepwise until identifying a set of 6 predictive metabolites. A 6-metabolite predictive logistic regression model showed a sensitivity of 0.91(95% CI 0.69-0.99 and a specificity 0.84 (95% CI 0.58-0.94 with an AUC of 0.93 (95% CI 0.89-1.01. Myristic acid was the single most predictive metabolite, with a sensitivity of 1.00 (95% CI 0.85-1.00 and specificity of 0.95 (95% CI 0.74-0.99, and performed better than various combinations of conventional laboratory and clinical parameters. We found that a metabolomics approach for analysis of acute blood samples was useful for identification of patients with bacteremic sepsis. Metabolomics should be further evaluated as a new tool for infection diagnostics.

  17. Metabolite variability in Caribbean sponges of the genus Aplysina

    Directory of Open Access Journals (Sweden)

    Monica Puyana

    Full Text Available Abstract Sponges of the genus Aplysina are among the most common benthic animals on reefs of the Caribbean, and display a wide diversity of morphologies and colors. Tissues of these sponges lack mineralized skeletal elements, but contain a dense spongin skeleton and an elaborate series of tyrosine-derived brominated alkaloid metabolites that function as chemical defenses against predatory fishes, but do not deter some molluscs. Among the earliest marine natural products to be isolated and identified, these metabolites remain the subject of intense interest for commercial applications because of their activities in various bioassays. In this study, crude organic extracts from 253 sponges from ten morphotypes among the species Aplysina archeri,Aplysina bathyphila,Aplysina cauliformis,Aplysina fistularis,Aplysina fulva,A. insularis, and Aplysina lacunosa were analyzed by liquid chromatography–mass spectrometry (LC–MS to characterize the pattern of intra- and interspecific variabilities of the twelve major secondary metabolites present therein. Patterns across Aplysina species ranged from the presence of mostly a single compound, fistularin-3, in A. cauliformis, to a mixture of metabolites present in the other species. These patterns did not support the biotransformation hypothesis for conversion of large molecular weight molecules to smaller ones for the purpose of enhanced defense. Discriminant analyses of the metabolite data revealed strong taxonomic patterns that support a close relationship between A. fistularis,A. fulva and A. insularis, while two morphotypes of A. cauliformis (lilac creeping vs. brown erect were very distinct. Two morphotypes of A. lacunosa, one with hard tissue consistency, the other soft and thought to belong to a separate genus (Suberea, had very similar chemical profiles. Of the twelve metabolites found among samples, variation in fistularin-3, dideoxyfistularin-3 and hydroxyaerothionin provided the most predictive

  18. Mass-charge-heat coupled transfers in a single cell of a proton exchange membrane fuel cell; Transferts couples masse-charge-chaleur dans une cellule de pile a combustible a membrane polymere

    Energy Technology Data Exchange (ETDEWEB)

    Ramousse, J

    2005-11-15

    Understanding and modelling of coupled mass, charges and heat transfers phenomena are fundamental to analyze the electrical behaviour of the system. The aim of the present model is to describe electrical performances of a PEFMC according to the fluidic and thermal operating conditions. The water content of the membrane and the water distribution in the single cell are estimated according to the coupled simulations of mass transport in the thickness of the single cell and in the feeding channels of the bipolar plates. A microscopic model of a Gas Diffusion Electrode is built up to describe charges transfer phenomena occurring at the electrodes. Completed by a study of heat transfer in the Membrane Electrode Assembly, conditions and preferential sites of water vapor condensation can be highlighted. A set of measurements of the effective thermal conductivity of carbon felts used in fuel cells as porous backing layers have also been performed. Although the value of this parameter is essential for the study of heat transfer, it is still under investigation because of the strong thermal anisotropy of the medium. (author)

  19. Lateral charge transport from heavy-ion tracks in integrated circuit chips

    Science.gov (United States)

    Zoutendyk, J. A.; Schwartz, H. R.; Nevill, L. R.

    1988-01-01

    A 256K DRAM has been used to study the lateral transport of charge (electron-hole pairs) induced by direct ionization from heavy-ion tracks in an IC. The qualitative charge transport has been simulated using a two-dimensional numerical code in cylindrical coordinates. The experimental bit-map data clearly show the manifestation of lateral charge transport in the creation of adjacent multiple-bit errors from a single heavy-ion track. The heavy-ion data further demonstrate the occurrence of multiple-bit errors from single ion tracks with sufficient stopping power. The qualitative numerical simulation results suggest that electric-field-funnel-aided (drift) collection accounts for single error generated by an ion passing through a charge-collecting junction, while multiple errors from a single ion track are due to lateral diffusion of ion-generated charge.

  20. Faster metabolite (1H transverse relaxation in the elder human brain.

    Directory of Open Access Journals (Sweden)

    Małgorzata Marjańska

    Full Text Available (1H magnetic resonance spectroscopy (MRS is unique among imaging modalities because signals from several metabolites are measured during a single examination period. Each metabolite reflects a distinct intracellular process. Furthermore transverse (T2 relaxation times probe the viability of the cell microenvironment, e.g., the viscosity of the cellular fluids, the microscopic susceptibility distribution within the cells, and the iron content. In this study, T2s of brain metabolites were measured in the occipital lobe of eighteen young and fourteen elderly subjects at a field strength of 4 tesla. The T2s of N-acetylaspartate, total creatine, and total choline were 23%, 16% and 10% shorter in elderly than in young subjects. The findings of this study suggest that noninvasive detection of T2 provides useful biological information on changes in the cellular microenvironment that take place during aging.

  1. Dynamics of Charged Excitons and Biexcitons in CsPbBr3 Perovskite Nanocrystals Revealed by Femtosecond Transient-Absorption and Single-Dot Luminescence Spectroscopy.

    Science.gov (United States)

    Yarita, Naoki; Tahara, Hirokazu; Ihara, Toshiyuki; Kawawaki, Tokuhisa; Sato, Ryota; Saruyama, Masaki; Teranishi, Toshiharu; Kanemitsu, Yoshihiko

    2017-04-06

    Metal-halide perovskite nanocrystals (NCs) are promising photonic materials for use in solar cells, light-emitting diodes, and lasers. The optoelectronic properties of these devices are determined by the excitons and exciton complexes confined in their NCs. In this study, we determined the relaxation dynamics of charged excitons and biexcitons in CsPbBr 3 NCs using femtosecond transient-absorption (TA), time-resolved photoluminescence (PL), and single-dot second-order photon correlation spectroscopy. Decay times of ∼40 and ∼200 ps were obtained from the TA and PL decay curves for biexcitons and charged excitons, respectively, in NCs with an average edge length of 7.7 nm. The existence of charged excitons even under weak photoexcitation was confirmed by the second-order photon correlation measurements. We found that charged excitons play a dominant role in luminescence processes of CsPbBr 3 NCs. Combining different spectroscopic techniques enabled us to clarify the dynamical behaviors of excitons, charged excitons, and biexcitons.

  2. Glycogen Synthesis and Metabolite Overflow Contribute to Energy Balancing in Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Melissa Cano

    2018-04-01

    Full Text Available Summary: Understanding how living cells manage high-energy metabolites such as ATP and NADPH is essential for understanding energy transformations in the biosphere. Using light as the energy input, we find that energy charge (ratio of ATP over ADP+ATP in the cyanobacterium Synechocystis sp. PCC 6803 varies in different growth stages, with a peak upon entry into the rapid growth phase, as well as a positive correlation with light intensity. In contrast, a mutant that can no longer synthesize the main carbon storage compound glycogen showed higher energy charge. The overflow of organic acids in this mutant under nitrogen depletion could also be triggered under high light in nitrogen-replete conditions, with an energy input level dependency. These findings suggest that energy charge in cyanobacteria is tightly linked to growth and carbon partition and that energy management is of key significance for their application as photosynthetic carbon dioxide-assimilating cell factories. : Cano et al. find that ATP levels in a cyanobacterium are dynamic in growth phases and respond to intracellular and environmental conditions. A glycogen mutant excretes organic acids and adjusts photosynthesis as alternative strategies to maintain energy homeostasis. Keywords: cyanobacteria, synechocystis, energy charge, glycogen, overflow metabolism, photosynthesis

  3. Immune regulation by microbiome metabolites.

    Science.gov (United States)

    Kim, Chang H

    2018-03-22

    Commensal microbes and the host immune system have been co-evolved for mutual regulation. Microbes regulate the host immune system, in part, by producing metabolites. A mounting body of evidence indicates that diverse microbial metabolites profoundly regulate the immune system via host receptors and other target molecules. Immune cells express metabolite-specific receptors such as P2X 7 , GPR41, GPR43, GPR109A, aryl hydrocarbon receptor precursor (AhR), pregnane X receptor (PXR), farnesoid X receptor (FXR), TGR5 and other molecular targets. Microbial metabolites and their receptors form an extensive array of signals to respond to changes in nutrition, health and immunological status. As a consequence, microbial metabolite signals contribute to nutrient harvest from diet, and regulate host metabolism and the immune system. Importantly, microbial metabolites bidirectionally function to promote both tolerance and immunity to effectively fight infection without developing inflammatory diseases. In pathogenic conditions, adverse effects of microbial metabolites have been observed as well. Key immune-regulatory functions of the metabolites, generated from carbohydrates, proteins and bile acids, are reviewed in this article. © 2018 John Wiley & Sons Ltd.

  4. New Methodology for Known Metabolite Identification in Metabonomics/Metabolomics: Topological Metabolite Identification Carbon Efficiency (tMICE).

    Science.gov (United States)

    Sanchon-Lopez, Beatriz; Everett, Jeremy R

    2016-09-02

    A new, simple-to-implement and quantitative approach to assessing the confidence in NMR-based identification of known metabolites is introduced. The approach is based on a topological analysis of metabolite identification information available from NMR spectroscopy studies and is a development of the metabolite identification carbon efficiency (MICE) method. New topological metabolite identification indices are introduced, analyzed, and proposed for general use, including topological metabolite identification carbon efficiency (tMICE). Because known metabolite identification is one of the key bottlenecks in either NMR-spectroscopy- or mass spectrometry-based metabonomics/metabolomics studies, and given the fact that there is no current consensus on how to assess metabolite identification confidence, it is hoped that these new approaches and the topological indices will find utility.

  5. Monitoring MDMA metabolites in urban wastewater as novel biomarkers of consumption.

    Science.gov (United States)

    González-Mariño, Iria; Zuccato, Ettore; Santos, Miquel M; Castiglioni, Sara

    2017-05-15

    Consumption of 3,4-methylendioxymethamphetamine (MDMA) has been always estimated by measuring the parent substance through chemical analysis of wastewater. However, this may result in an overestimation of the use if the substance is directly disposed in sinks or toilets. Using specific urinary metabolites may overcome this limitation. This study investigated for the first time the suitability of a panel of MDMA metabolites as biomarkers of consumption, considering the specific criteria recently proposed, i.e. being detectable and stable in wastewater, being excreted in a known percentage in urine, and having human excretion as the sole source. A new analytical method was developed and validated for the extraction and analysis of MDMA and three of its main metabolites in wastewater. 24-h composite raw wastewater samples from three European cities were analysed and MDMA use was back-calculated. Results from single MDMA loads, 4-hydroxy-3-methoxymethamphetamine (HMMA) loads and from the sum of MDMA, HMMA and 4-hydroxy-3-methoxyamphetamine (HMA) loads were in line with the well-known recreational use of this drug: consumption was higher during the weekend in all cities. HMMA and HMA turned out to be suitable biomarkers of consumption; however, concentrations measured in wastewater did not resemble the expected pharmacokinetic profiles, quite likely due to the very limited information available on excretion profiles. Different options were tested to back-calculate MDMA use, including the sum of MDMA and its metabolites, to balance the biases associated with each single substance. Nevertheless, additional pharmacokinetic studies are urgently needed in order to get more accurate excretion rates and, therefore, improve the estimates of MDMA use. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Detection of tamoxifen metabolites by GC-MSD.

    Science.gov (United States)

    Báez, H; Camargo, C; Osorio, H; Umpiérrez, F

    2004-01-01

    Tamoxifen is an antiestrogen used in the adjuvant endocrine therapy of early breast cancer and malignant breast disorders. It is also used in women with anovulatory infertility caused by its stimulating effect on the secretion of the pituitary gonadotrophic hormones. In males it could increase the endogenous production of androgens. Because of these properties tamoxifen may be misused in some sports to treat the androgens suppression caused by the extensive abuse of anabolic androgenic steroids. A method for identification and confirmation of tamoxifen metabolites is described. Hydroxymetoxytamoxifen is detected in urine by gas chromatography and mass spectrometry in a selective ion monitoring method followed by the routine postrun in the screening of anabolic steroids. Once the hydroxymetoxytamoxifen is detected, confirmation of reported metabolites could be performed with a 5973 mass selective detector in the scan mode after solid-phase extraction by cationic exchange. This study also reports an excretion profile for a single dose of tamoxifen equivalent to 40 mg administrated orally to two males volunteers.

  7. Spectrally resolved single-molecule electrometry

    Science.gov (United States)

    Ruggeri, F.; Krishnan, M.

    2018-03-01

    Escape-time electrometry is a recently developed experimental technique that offers the ability to measure the effective electrical charge of a single biomolecule in solution with sub-elementary charge precision. The approach relies on measuring the average escape-time of a single charged macromolecule or molecular species transiently confined in an electrostatic fluidic trap. Comparing the experiments with the predictions of a mean-field model of molecular electrostatics, we have found that the measured effective charge even reports on molecular conformation, e.g., folded or disordered state, and non-uniform charge distribution in disordered proteins or polyelectrolytes. Here we demonstrate the ability to use the spectral dimension to distinguish minute differences in electrical charge between individual molecules or molecular species in a single simultaneous measurement, under identical experimental conditions. Using one spectral channel for referenced measurement, this kind of photophysical distinguishability essentially eliminates the need for accurate knowledge of key experimental parameters, otherwise obtained through intensive characterization of the experimental setup. As examples, we demonstrate the ability to detect small differences (˜5%) in the length of double-stranded DNA fragments as well as single amino acid exchange in an intrinsically disordered protein, prothymosin α.

  8. Does prescribed burning affect leaf secondary metabolites in pine stands?

    Science.gov (United States)

    Lavoir, A V; Ormeño, E; Pasqualini, V; Ferrat, L; Greff, S; Lecareux, C; Vila, B; Mévy, J P; Fernandez, C

    2013-03-01

    Prescribed burning (PB) is gaining popularity as a low-cost forest protection measure that efficiently reduces fuel build-up, but its effects on tree health and growth are poorly understood. Here, we evaluated the impact of PB on plant defenses in Mediterranean pine forests (Pinus halepensis and P. nigra ssp. laricio). These chemical defenses were estimated based on needle secondary metabolites (terpenes and phenolics including flavonoids) and discussed in terms of chlorophyll fluorescence and soil nutrients. Three treatments were applied: absence of burning (control plots); single burns (plots burned once); and repeated burns (plots burned twice). For single burns, we also explored changes over time. In P. laricio, PB tended to trigger only minor modifications consisting exclusively of short-lived increases (observed within 3 months after PB) in flavonoid index, possibly due to the leaf temperature increase during PB. In P. halepensis, PB had detrimental effects on physiological performance, consisting of (i) significant decreases in actual PSII efficiency (ΦPSII) in light-adapted conditions after repeated PB, and (ii) short-lived decreases in variable-to-maximum fluorescence ratio (Fv/Fm) after single PB, indicating that PB actually stressed P. halepensis trees. Repeated PB also promoted terpene-like metabolite production, which increased 2 to 3-fold compared to control trees. Correlations between terpene metabolites and soil chemistry were found. These results suggest that PB impacts needle secondary metabolism both directly (via a temperature impact) and indirectly (via soil nutrients), and that these impacts vary according to species/site location, frequency and time elapsed since last fire. Our findings are discussed with regard to the use of PB as a forest management technique and its consequences on plant investment in chemical defenses.

  9. Changes in hippocampal metabolites after effective treatment for fibromyalgia: a case study.

    Science.gov (United States)

    Wood, Patrick B; Ledbetter, Christina R; Patterson, James C

    2009-01-01

    Fibromyalgia has been associated with disrupted hippocampal brain metabolite ratios by studies using single voxel magnetic resonance spectroscopy (1H-MRS). Exposure to stress is considered a risk factor for the development and exacerbation of fibromyalgia symptoms. Basic science has demonstrated the hippocampus to be exquisitely sensitive to the effects of stressful experience, which results in changes including alterations in metabolite content and frank atrophy. This report details the case of a 47-year-old woman with fibromyalgia who was originally found to have a profound depression of the ratio of N-acetylaspartate to creatine in her right hippocampus during participation in a study to assess brain metabolite disturbances in fibromyalgia utilizing single voxel proton magnetic resonance spectroscopy. An individualized treatment strategy was developed based both on physiological abnormalities associated with the disorder and symptoms that characterized the patient's unique clinical profile. Clinical and spectroscopic evaluation following nine months of treatment demonstrated both an improvement in her clinical profile and normalization of the NAA/Cr ratio within her right hippocampus. Therapeutic strategies aimed at demonstrable lesions associated with fibromyalgia appear to represent rational targets for pharmacological intervention. The rationale for development of novel pharmacotherapies for this unusual disorder is discussed.

  10. Charge-symmetry-breaking nucleon form factors

    International Nuclear Information System (INIS)

    Kubis, Bastian

    2011-01-01

    A quantitative understanding of charge-symmetry breaking is an increasingly important ingredient for the extraction of the nucleon’s strange vector form factors. We review the theoretical understanding of the charge-symmetry-breaking form factors, both for single nucleons and for 4 He.

  11. Interactions between Plant Metabolites Affect Herbivores: A Study with Pyrrolizidine Alkaloids and Chlorogenic Acid

    Science.gov (United States)

    Liu, Xiaojie; Vrieling, Klaas; Klinkhamer, Peter G.L.

    2017-01-01

    The high structural diversity of plant metabolites suggests that interactions among them should be common. We investigated the effects of single metabolites and combinations of plant metabolites on insect herbivores. In particular we studied the interacting effects of pyrrolizidine alkaloid (PAs), and chlorogenic acid (CGA), on a generalist herbivore, Frankliniella occidentalis. We studied both the predominantly occurring PA N-oxides and the less frequent PA free bases. We found antagonistic effects between CGA and PA free bases on thrips mortality. In contrast PA N-oxides showed synergistic interactions with CGA. PA free bases caused a higher thrips mortality than PA N-oxides while the reverse was through for PAs in combination with CGA. Our results provide an explanation for the predominate storage of PA N-oxides in plants. We propose that antagonistic interactions represent a constraint on the accumulation of plant metabolites, as we found here for Jacobaea vulgaris. The results show that the bioactivity of a given metabolite is not merely dependent upon the amount and chemical structure of that metabolite, but also on the co-occurrence metabolites in, e.g., plant cells, tissues and organs. The significance of this study is beyond the concerns of the two specific groups tested here. The current study is one of the few studies so far that experimentally support the general conception that the interactions among plant metabolites are of great importance to plant-environment interactions. PMID:28611815

  12. Interactions between Plant Metabolites Affect Herbivores: A Study with Pyrrolizidine Alkaloids and Chlorogenic Acid

    Directory of Open Access Journals (Sweden)

    Xiaojie Liu

    2017-05-01

    Full Text Available The high structural diversity of plant metabolites suggests that interactions among them should be common. We investigated the effects of single metabolites and combinations of plant metabolites on insect herbivores. In particular we studied the interacting effects of pyrrolizidine alkaloid (PAs, and chlorogenic acid (CGA, on a generalist herbivore, Frankliniella occidentalis. We studied both the predominantly occurring PA N-oxides and the less frequent PA free bases. We found antagonistic effects between CGA and PA free bases on thrips mortality. In contrast PA N-oxides showed synergistic interactions with CGA. PA free bases caused a higher thrips mortality than PA N-oxides while the reverse was through for PAs in combination with CGA. Our results provide an explanation for the predominate storage of PA N-oxides in plants. We propose that antagonistic interactions represent a constraint on the accumulation of plant metabolites, as we found here for Jacobaea vulgaris. The results show that the bioactivity of a given metabolite is not merely dependent upon the amount and chemical structure of that metabolite, but also on the co-occurrence metabolites in, e.g., plant cells, tissues and organs. The significance of this study is beyond the concerns of the two specific groups tested here. The current study is one of the few studies so far that experimentally support the general conception that the interactions among plant metabolites are of great importance to plant-environment interactions.

  13. Identification of Urinary Polyphenol Metabolite Patterns Associated with Polyphenol-Rich Food Intake in Adults from Four European Countries

    Directory of Open Access Journals (Sweden)

    Hwayoung Noh

    2017-07-01

    Full Text Available We identified urinary polyphenol metabolite patterns by a novel algorithm that combines dimension reduction and variable selection methods to explain polyphenol-rich food intake, and compared their respective performance with that of single biomarkers in the European Prospective Investigation into Cancer and Nutrition (EPIC study. The study included 475 adults from four European countries (Germany, France, Italy, and Greece. Dietary intakes were assessed with 24-h dietary recalls (24-HDR and dietary questionnaires (DQ. Thirty-four polyphenols were measured by ultra-performance liquid chromatography–electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS-MS in 24-h urine. Reduced rank regression-based variable importance in projection (RRR-VIP and least absolute shrinkage and selection operator (LASSO methods were used to select polyphenol metabolites. Reduced rank regression (RRR was then used to identify patterns in these metabolites, maximizing the explained variability in intake of pre-selected polyphenol-rich foods. The performance of RRR models was evaluated using internal cross-validation to control for over-optimistic findings from over-fitting. High performance was observed for explaining recent intake (24-HDR of red wine (r = 0.65; AUC = 89.1%, coffee (r = 0.51; AUC = 89.1%, and olives (r = 0.35; AUC = 82.2%. These metabolite patterns performed better or equally well compared to single polyphenol biomarkers. Neither metabolite patterns nor single biomarkers performed well in explaining habitual intake (as reported in the DQ of polyphenol-rich foods. This proposed strategy of biomarker pattern identification has the potential of expanding the currently still limited list of available dietary intake biomarkers.

  14. Evaluation of Extraction Protocols for Simultaneous Polar and Non-Polar Yeast Metabolite Analysis Using Multivariate Projection Methods

    Directory of Open Access Journals (Sweden)

    Nicolas P. Tambellini

    2013-07-01

    Full Text Available Metabolomic and lipidomic approaches aim to measure metabolites or lipids in the cell. Metabolite extraction is a key step in obtaining useful and reliable data for successful metabolite studies. Significant efforts have been made to identify the optimal extraction protocol for various platforms and biological systems, for both polar and non-polar metabolites. Here we report an approach utilizing chemoinformatics for systematic comparison of protocols to extract both from a single sample of the model yeast organism Saccharomyces cerevisiae. Three chloroform/methanol/water partitioning based extraction protocols found in literature were evaluated for their effectiveness at reproducibly extracting both polar and non-polar metabolites. Fatty acid methyl esters and methoxyamine/trimethylsilyl derivatized aqueous compounds were analyzed by gas chromatography mass spectrometry to evaluate non-polar or polar metabolite analysis. The comparative breadth and amount of recovered metabolites was evaluated using multivariate projection methods. This approach identified an optimal protocol consisting of 64 identified polar metabolites from 105 ion hits and 12 fatty acids recovered, and will potentially attenuate the error and variation associated with combining metabolite profiles from different samples for untargeted analysis with both polar and non-polar analytes. It also confirmed the value of using multivariate projection methods to compare established extraction protocols.

  15. Charge-symmetry-breaking nucleon form factors

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, Bastian, E-mail: kubis@hiskp.uni-bonn.de [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics (Germany)

    2011-11-15

    A quantitative understanding of charge-symmetry breaking is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors. We review the theoretical understanding of the charge-symmetry-breaking form factors, both for single nucleons and for {sup 4}He.

  16. Non-Covalent Interactions and Impact of Charge Penetration Effects in Linear Oligoacene Dimers and Single Crystals

    KAUST Repository

    Ryno, Sean

    2016-05-18

    Non-covalent interactions determine in large part the thermodynamic aspects of molecular packing in organic crystals. Using a combination of symmetry-adapted perturbation theory (SAPT) and classical multipole electrostatics, we describe the interaction potential energy surfaces for dimers of the oligoacene family, from benzene to hexacene. An analysis of these surfaces and a thorough assessment of dimers extracted from the reported crystal structures underline that high-order interactions (i.e., three-body non-additive interactions) must be considered in order to rationalize the details of the crystal structures. A comparison of the SAPT electrostatic energy with the multipole interaction energy demonstrates the importance of the contribution of charge penetration, which is shown to account for up to 50% of the total interaction energy in dimers extracted from the experimental single crystals; in the case of the most stable co-facial model dimers, this contribution is even larger than the total interaction energy. Our results highlight the importance of taking account of charge penetration in studies of the larger oligoacenes.

  17. The radioimmunological determination of glibenclamide and its metabolites in serum

    International Nuclear Information System (INIS)

    Glogner, P.; Heni, N.; Nissen, L.

    1977-01-01

    This report describes a sensitive and specific radio-immunological method for determining serum levels of the 1-(p-[2- (5-chloro-2-methoxybenzamido) -ethyl]-benzenesulfonyl) -3-cyclohexylurea (clibenclamide) and its metabolites. The antigen was prepared by coupling a metabolite to bovine serum albumin. Antibodies could be demonstrated in serum after immunisation of rabbits. The separation of free and antibody-bound glibenclamide was achieved by a dextran-charcoal suspension. Presence of serum did not influence the binding characteristics. The limit of detection was 20 ng/ml. The affinity of the metabolites differed only slightly from that of glibenclamide. The presence of related drugs from the sulfonylurea series such as tolbutamide, glibornuride and the sulfonamide sulfamethoxazol did not affect the determination. Only closely related substances showed a variable degree of affinity towards antibodies. As an example of the possible application of this method, the serum concentration of glibenclamide was determined over a period of 8 h after single i.v. injection to a volunteer. The data are in close accordance with the results of authors using radioactive glibenclamide. (orig.) [de

  18. Electrochemical charging of the single-layer graphene membrane

    Czech Academy of Sciences Publication Activity Database

    Komínková, Zuzana; Kalbáč, Martin

    2016-01-01

    Roč. 253, č. 12 (2016), s. 2331-2335 ISSN 0370-1972 R&D Projects: GA MŠk LL1301; GA ČR(CZ) GBP208/12/G016 Institutional support: RVO:61388955 Keywords : electrochemical charging * graphene membrane * in situ Raman spectroelectrochemistry Subject RIV: CG - Electrochemistry Impact factor: 1.674, year: 2016

  19. Giant plasmon excitation in single and double ionization of C60 by fast highly charged Si and O ions

    International Nuclear Information System (INIS)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C

    2007-01-01

    Se have investigated single and double ionization of C 60 molecule in collisions with 2.33 MeV/u Si q+ (q=6-14) and 3.125 MeV/u O q+ (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C 60 are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening

  20. Measurement and Calculation of Absolute Single- and Multiple-Charge-Exchange Cross Sections for Feq+ Ions Impacting CO and CO2

    Energy Technology Data Exchange (ETDEWEB)

    Simcic, J. [Jet Propulsion Laboratory/Caltech; Schultz, David Robert [ORNL; Mawhorter, R. J. [Pomona College; Cadez, I. [Jozef Stefan Institute, Slovenia; Greenwood, J. B. [Queen' s University, Belfast; Chutjian, A. [Jet Propulsion Laboratory/Caltech; Lisse, Carey M. [Johns Hopkins University; Smith, S. J. [Indiana Wesleyan University, Marion

    2010-01-01

    Absolute cross sections are reported for single, double, and triple charge exchange of Feq+ (q=5- 13) ions with CO and CO2. The highly-charged Fe ions are generated in an electron cyclotron resonance ion source. Absolute data are derived from knowledge of the target gas pressure, target path length, and incident and charge-exchanged ion currents. Experimental results are compared with new calculations of these cross sections in the n-electron classical trajectory Monte-Carlo approximation, in which the ensuing radiative and non-radiative cascades are approximated with scaled hydrogenic transition probabilities and scaled Auger rates. The present data are needed in astrophysical applications of solar- and stellar-wind charge-exchange with comets, planetary atmospheres, and circumstellar clouds.

  1. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kada, W., E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Y.; Ando, Y. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Onoda, S. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Umezawa, H.; Mokuno, Y. [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Shikata, S. [Kwansei Gakuin Univ., 2-1, Gakuen, Mita, Hyogo 669-1337 (Japan); Makino, T.; Koka, M. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hanaizumi, O. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kamiya, T.; Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  2. Simultaneous fecal microbial and metabolite profiling enables accurate classification of pediatric irritable bowel syndrome.

    Science.gov (United States)

    Shankar, Vijay; Reo, Nicholas V; Paliy, Oleg

    2015-12-09

    We previously showed that stool samples of pre-adolescent and adolescent US children diagnosed with diarrhea-predominant IBS (IBS-D) had different compositions of microbiota and metabolites compared to healthy age-matched controls. Here we explored whether observed fecal microbiota and metabolite differences between these two adolescent populations can be used to discriminate between IBS and health. We constructed individual microbiota- and metabolite-based sample classification models based on the partial least squares multivariate analysis and then applied a Bayesian approach to integrate individual models into a single classifier. The resulting combined classification achieved 84 % accuracy of correct sample group assignment and 86 % prediction for IBS-D in cross-validation tests. The performance of the cumulative classification model was further validated by the de novo analysis of stool samples from a small independent IBS-D cohort. High-throughput microbial and metabolite profiling of subject stool samples can be used to facilitate IBS diagnosis.

  3. Virtual quantification of metabolites by capillary electrophoresis-electrospray ionization-mass spectrometry: predicting ionization efficiency without chemical standards.

    Science.gov (United States)

    Chalcraft, Kenneth R; Lee, Richard; Mills, Casandra; Britz-McKibbin, Philip

    2009-04-01

    A major obstacle in metabolomics remains the identification and quantification of a large fraction of unknown metabolites in complex biological samples when purified standards are unavailable. Herein we introduce a multivariate strategy for de novo quantification of cationic/zwitterionic metabolites using capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) based on fundamental molecular, thermodynamic, and electrokinetic properties of an ion. Multivariate calibration was used to derive a quantitative relationship between the measured relative response factor (RRF) of polar metabolites with respect to four physicochemical properties associated with ion evaporation in ESI-MS, namely, molecular volume (MV), octanol-water distribution coefficient (log D), absolute mobility (mu(o)), and effective charge (z(eff)). Our studies revealed that a limited set of intrinsic solute properties can be used to predict the RRF of various classes of metabolites (e.g., amino acids, amines, peptides, acylcarnitines, nucleosides, etc.) with reasonable accuracy and robustness provided that an appropriate training set is validated and ion responses are normalized to an internal standard(s). The applicability of the multivariate model to quantify micromolar levels of metabolites spiked in red blood cell (RBC) lysates was also examined by CE-ESI-MS without significant matrix effects caused by involatile salts and/or major co-ion interferences. This work demonstrates the feasibility for virtual quantification of low-abundance metabolites and their isomers in real-world samples using physicochemical properties estimated by computer modeling, while providing deeper insight into the wide disparity of solute responses in ESI-MS. New strategies for predicting ionization efficiency in silico allow for rapid and semiquantitative analysis of newly discovered biomarkers and/or drug metabolites in metabolomics research when chemical standards do not exist.

  4. Effect of multiple plasmon excitation on single, double and multiple ionizations of C{sub 60} in collisions with fast highly charged Si ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

    2007-06-28

    We have investigated the single and multiple ionizations of the C{sub 60} molecule in collisions with fast Si{sup q+} projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.

  5. Study of single pion production in antineutrino induced charged current interactions

    International Nuclear Information System (INIS)

    Bolognese, Teresa.

    1978-01-01

    Results are presented on the exclusive charged current antineutrino production of one pion using the data of the Gargamelle propane experiment at CERN PS. The isospin structure of the charged weak current is studied as well as the energy dependence of the total cross section for π - antineutrino production, which is compared with the prediction of Adler's model [fr

  6. Rationalization and prediction of in vivo metabolite exposures: The role of metabolite kinetics, clearance predictions and in vitro parameters

    Science.gov (United States)

    Lutz, Justin D.; Fujioka, Yasushi; Isoherranen, Nina

    2010-01-01

    Importance of the field Due to growing concerns over toxic or active metabolites, significant efforts have been focused on qualitative identification of potential in vivo metabolites from in vitro data. However, limited tools are available to quantitatively predict their human exposures. Areas covered in this review Theory of clearance predictions and metabolite kinetics is reviewed together with supporting experimental data. In vitro and in vivo data of known circulating metabolites and their parent drugs was collected and the predictions of in vivo exposures of the metabolites were evaluated. What the reader will gain The theory and data reviewed will be useful in early identification of human metabolites that will circulate at significant levels in vivo and help in designing in vivo studies that focus on characterization of metabolites. It will also assist in rationalization of metabolite-to-parent ratios used as markers of specific enzyme activity. Take home message The relative importance of a metabolite in comparison to the parent compound as well as other metabolites in vivo can only be predicted using the metabolites in vitro formation and elimination clearances, and the in vivo disposition of a metabolite can only be rationalized when the elimination pathways of that metabolite are known. PMID:20557268

  7. Caffeine metabolites not caffeine protect against riboflavin photosensitized oxidative damage related to skin and eye health

    DEFF Research Database (Denmark)

    Scurachio, R. S.; Mattiucci, F.; Santos, W. G.

    2016-01-01

    . Caffeine metabolites rather than caffeine seem accordingly important for the observed protective effect against cutaneous melanoma identified for drinkers of regular but not of decaffeinated coffee. The caffeine metabolites, but not caffeine, were by time resolved single photon counting found to quench...... singlet excited riboflavin through exothermic formation of ground-state precursor complexes indicating importance of hydrogen bounding through keto-enol tautomer's for protection of oxidizable substrates and sensitive structures against riboflavin photosensitization....

  8. Metabolite Profiling of Red Sea Corals

    KAUST Repository

    Ortega, Jovhana Alejandra

    2016-12-01

    Looking at the metabolite profile of an organism provides insights into the metabolomic state of a cell and hence also into pathways employed. Little is known about the metabolites produced by corals and their algal symbionts. In particular, corals from the central Red Sea are understudied, but interesting study objects, as they live in one of the warmest and most saline environments and can provide clues as to the adjustment of corals to environmental change. In this study, we applied gas chromatography – mass spectrometry (GC–MS) metabolite profiling to analyze the metabolic profile of four coral species and their associated symbionts: Fungia granulosa, Acropora hemprichii, Porites lutea, and Pocillopora verrucosa. We identified and quantified 102 compounds among primary and secondary metabolites across all samples. F. granulosa and its symbiont showed a total of 59 metabolites which were similar to the 51 displayed by P. verrucosa. P. lutea and A. hemprichii both harbored 40 compounds in conjunction with their respective isolated algae. Comparing across species, 28 metabolites were exclusively present in algae, while 38 were exclusive to corals. A principal component and cluster analyses revealed that metabolite profiles clustered between corals and algae, but each species harbored a distinct catalog of metabolites. The major classes of compounds were carbohydrates and amino acids. Taken together, this study provides a first description of metabolites of Red Sea corals and their associated symbionts. As expected, the metabolites of coral hosts differ from their algal symbionts, but each host and algal species harbor a unique set of metabolites. This corroborates that host-symbiont species pairs display a fine-tuned complementary metabolism that provide insights into the specific nature of the symbiosis. Our analysis also revealed aquatic pollutants, which suggests that metabolite profiling might be used for monitoring pollution levels and assessing

  9. Charge Dependence and Electric Quadrupole Effects on Single-Nucleon Removal in Relativistic and Intermediate Energy Nuclear Collisions

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Single nucleon removal in relativistic and intermediate energy nucleus-nucleus collisions is studied using a generalization of Weizsacker-Williams theory that treats each electromagnetic multipole separately. Calculations are presented for electric dipole and quadrupole excitations and incorporate a realistic minimum impact parameter, Coulomb recoil corrections, and the uncertainties in the input photonuclear data. Discrepancies are discussed. The maximum quadrupole effect to be observed in future experiments is estimated and also an analysis of the charge dependence of the electromagnetic cross sections down to energies as low as 100 MeV/nucleon is made.

  10. Charge state distributions from highly charged ions channeled at a metal surface

    International Nuclear Information System (INIS)

    Folkerts, L.; Meyer, F.W.; Schippers, S.

    1994-01-01

    The vast majority of the experimental work in the field of multicharged ion-surface interactions, to date, has focused on x-ray and particularly on electron emission. These experiments include measurements of the total electron yield, the emission statistics of the electrons, and, most of all, the electron energy distributions. So far, little attention has been paid to the fate of the multicharged projectile ions after the scattering. To our knowledge, the only measurement of the charge state distribution of the scattered ions is the pioneering experiment of de Zwart et al., who measured the total yield of scattered 1+, 2+, and 3+ ions as a function of the primary charge state q (q = 1--11) for 20 key Ne, Ar, and Kr ions after reflection from a polycrystalline tungsten target. Their main finding is the sudden onset of scattered 3+ ions when inner-shell vacancies are present in the primary particles. This suggests that a certain fraction of the inner-shell vacancies survives the entire collision event, and decays via autoionization on the outgoing path. Since the projectiles scattered in the neutral charge state could not be detected in the experiment of de Zwart et al., they were not able to provide absolute charge state fractions. In our present experiment, we focus on the scattered projectiles, measuring both the final charge state and the total scattering angle with a single 2D position sensitive detector (PSD). This method gives us the number of positive, as well as neutral and negative, scattered ions, thus allowing us to extract absolute charge state fractions. Using a well-prepared single Au(110) crystal and a grazing incidence geometry, we were able to observe surface channeling along the [001] channels

  11. Single and double charge transfer in Be/sup 4+/+He collisions: A molecular (Feshbach) approach

    International Nuclear Information System (INIS)

    Martin, F.; Riera, A.; Yaez, M.

    1986-01-01

    In recent articles, we pointed out the fundamental difference between the molecular treatment of processes involving a multicharged ion and hydrogen or helium atoms, which is the (formal) autoionizing character of the molecular channels, and we reported a (new) implementation of the Feshbach method to calculate the molecular energies and couplings. In the present work we use the wave functions calculated with this Feshbach method for the BeHe/sup 4+/ quasimolecule, introduce a common translation factor in the formalism, and calculate the single and double charge-exchange cross sections in Be/sup 4+/+He(1s 2 ) collisions for impact energies 0.2--20 keV/amu. The mechanisms of the processes are discussed in detail

  12. Single and double charge transfer in Be/sup 4+/+He collisions: A molecular (Feshbach) approach

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Riera, A.; Yaez, M.

    1986-12-01

    In recent articles, we pointed out the fundamental difference between the molecular treatment of processes involving a multicharged ion and hydrogen or helium atoms, which is the (formal) autoionizing character of the molecular channels, and we reported a (new) implementation of the Feshbach method to calculate the molecular energies and couplings. In the present work we use the wave functions calculated with this Feshbach method for the BeHe/sup 4+/ quasimolecule, introduce a common translation factor in the formalism, and calculate the single and double charge-exchange cross sections in Be/sup 4+/+He(1s/sup 2/) collisions for impact energies 0.2--20 keV/amu. The mechanisms of the processes are discussed in detail.

  13. Estimation of the spatial distribution of traps using space-charge-limited current measurements in an organic single crystal

    KAUST Repository

    Dacuña, Javier

    2012-09-06

    We used a mobility edge transport model and solved the drift-diffusion equation to characterize the space-charge-limited current of a rubrene single-crystal hole-only diode. The current-voltage characteristics suggest that current is injection-limited at high voltage when holes are injected from the bottom contact (reverse bias). In contrast, the low-voltage regime shows that the current is higher when holes are injected from the bottom contact as compared to hole injection from the top contact (forward bias), which does not exhibit injection-limited current in the measured voltage range. This behavior is attributed to an asymmetric distribution of trap states in the semiconductor, specifically, a distribution of traps located near the top contact. Accounting for a localized trap distribution near the contact allows us to reproduce the temperature-dependent current-voltage characteristics in forward and reverse bias simultaneously, i.e., with a single set of model parameters. We estimated that the local trap distribution contains 1.19×1011 cm -2 states and decays as exp(-x/32.3nm) away from the semiconductor-contact interface. The local trap distribution near one contact mainly affects injection from the same contact, hence breaking the symmetry in the charge transport. The model also provides information of the band mobility, energy barrier at the contacts, and bulk trap distribution with their corresponding confidence intervals. © 2012 American Physical Society.

  14. Metabolite profiling of carbamazepine and ibuprofen in Solea senegalensis bile using high-resolution mass spectrometry.

    Science.gov (United States)

    Aceña, Jaume; Pérez, Sandra; Eichhorn, Peter; Solé, Montserrat; Barceló, Damià

    2017-09-01

    The widespread occurrence of pharmaceuticals in the aquatic environment has raised concerns about potential adverse effects on exposed wildlife. Very little is currently known on exposure levels and clearance mechanisms of drugs in marine fish. Within this context, our research was focused on the identification of main metabolic reactions, generated metabolites, and caused effects after exposure of fish to carbamazepine (CBZ) and ibuprofen (IBU). To this end, juveniles of Solea senegalensis acclimated to two temperature regimes of 15 and 20 °C for 60 days received a single intraperitoneal dose of these drugs. A control group was administered the vehicle (sunflower oil). Bile samples were analyzed by ultra-high-performance liquid chromatography-high-resolution mass spectrometry on a Q Exactive (Orbitrap) system, allowing to propose plausible identities for 11 metabolites of CBZ and 13 metabolites of IBU in fish bile. In case of CBZ metabolites originated from aromatic and benzylic hydroxylation, epoxidation, and ensuing O-glucuronidation, O-methylation of a catechol-like metabolite was also postulated. Ibuprofen, in turn, formed multiple hydroxyl metabolites, O-glucuronides, and (hydroxyl)-acyl glucuronides, in addition to several taurine conjugates. Enzymatic responses after drug exposures revealed a water temperature-dependent induction of microsomal carboxylesterases. The metabolite profiling in fish bile provides an important tool for pharmaceutical exposure assessment. Graphical abstract Studies of metabolism of carbamazepine and ibuprofen in fish.

  15. Secondary metabolites from marine microorganisms.

    Science.gov (United States)

    Kelecom, Alphonse

    2002-03-01

    After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

  16. Secondary metabolites from marine microorganisms

    Directory of Open Access Journals (Sweden)

    KELECOM ALPHONSE

    2002-01-01

    Full Text Available After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

  17. In vivo metabolism of organophosphate flame retardants and distribution of their main metabolites in adult zebrafish.

    Science.gov (United States)

    Wang, Guowei; Chen, Hanyan; Du, Zhongkun; Li, Jianhua; Wang, Zunyao; Gao, Shixiang

    2017-07-15

    Understanding the metabolism of chemicals as well as the distribution and depuration of their main metabolites in tissues are essential for evaluating their fate and potential toxicity in vivo. Herein, we investigated the metabolism of six typical organophosphate (OP) flame retardants (tripropyl phosphate (TPRP), tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), tris(2-chloroethyl) phosphate (TCEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tri-p-cresyl phosphate (p-TCP)) in adult zebrafish in laboratory at three levels (0, 1/150 LC 50 (environmentally relevant level), and 1/30 LC 50 per OP analog). Twenty main metabolites were detected in the liver of OPs-exposed zebrafish using high resolution mass spectrometry (Q-TOF). The reaction pathways involving scission of the ester bond (hydrolysis), cleavage of the ether bond, oxidative hydroxylation, dechlorination, and coupling with glucuronic acid were proposed, and were further confirmed by the frontier electron density and point charge calculations. Tissue distribution of the twenty metabolites revealed that liver and intestine with the highest levels of metabolites were the most active organs for OPs biotransformation among the studied tissues of intestine, liver, roe, brain, muscle, and gill, which showed the importance of hepatobiliary system (liver-bile-intestine) in the metabolism and excretion of OPs in zebrafish. Fast depuration of metabolites from tissues indicated that the formed metabolites might be not persistent in fish, and easily released into water. This study provides comprehensive information on the metabolism of OPs in the tissue of zebrafish, which might give some hints for the exploration of their toxic mechanism in aquatic life. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Nuclear isovector giant resonances excited by pion single charge exchange

    International Nuclear Information System (INIS)

    King, B.H.

    1993-07-01

    This thesis is an experimental study of isovector giant resonances in light nuclei excited by pion single charge exchange reactions. Giant dipole resonances in light nuclei are known to be highly structured. For the mass 9 and 13 giant dipole resonances, isospin considerations were found to be very important to understanding this structure. by comparing the excitation functions from cross section measurements of the (π + , π 0 ) and (π, π 0 ) inclusive reactions, the authors determined the dominant isospin structure of the analog IVGR's. The comparison was made after decomposing the cross section into resonant and non-resonant components. This decomposition is made in the framework of strong absorption and quasi-free scattering. Measurements in the region of the isovector giant dipole resonances (IVGDR) were made to cover the inclusive angular distributions out to the second minimum. Study of the giant resonance decay process provides further understanding of the resonances. This study was carried out by observing the (π + , π 0 p) coincident reactions involving the resonances of 9 B and 13 N excited from 9 Be and 13 C nuclei. These measurements determined the spectra of the decay protons. This method also permitted a decomposition of the giant resonances into their isospin components. The multipolarities of the resonances were revealed by the decay proton angular correlations which, for dipoles, are of the form 1 + A 2 P 2 (cos θ)

  19. Design of Accumulators and Liquid/Gas Charging of Single Phase Mechanically Pumped Fluid Loop Heat Rejection Systems

    Science.gov (United States)

    Bhandari, Pradeep; Dudik, Brenda; Birur, Gajanana; Karlmann, Paul; Bame, David; Mastropietro, A. J.

    2012-01-01

    For single phase mechanically pumped fluid loops used for thermal control of spacecraft, a gas charged accumulator is typically used to modulate pressures within the loop. This is needed to accommodate changes in the working fluid volume due to changes in the operating temperatures as the spacecraft encounters varying thermal environments during its mission. Overall, the three key requirements on the accumulator to maintain an appropriate pressure range throughout the mission are: accommodation of the volume change of the fluid due to temperature changes, avoidance of pump cavitation and prevention of boiling in the liquid. The sizing and design of such an accumulator requires very careful and accurate accounting of temperature distribution within each element of the working fluid for the entire range of conditions expected, accurate knowledge of volume of each fluid element, assessment of corresponding pressures needed to avoid boiling in the liquid, as well as the pressures needed to avoid cavitation in the pump. The appropriate liquid and accumulator strokes required to accommodate the liquid volume change, as well as the appropriate gas volumes, require proper sizing to ensure that the correct pressure range is maintained during the mission. Additionally, a very careful assessment of the process for charging both the gas side and the liquid side of the accumulator is required to properly position the bellows and pressurize the system to a level commensurate with requirements. To achieve the accurate sizing of the accumulator and the charging of the system, sophisticated EXCEL based spreadsheets were developed to rapidly come up with an accumulator design and the corresponding charging parameters. These spreadsheets have proven to be computationally fast and accurate tools for this purpose. This paper will describe the entire process of designing and charging the system, using a case study of the Mars Science Laboratory (MSL) fluid loops, which is en route to

  20. Large tunable image-charge effects in single-molecule junctions.

    NARCIS (Netherlands)

    Perrin, M.L.; Verzijl, C.J.; Martin, C.A.; Shaikh, A.J.; Eelkema, R.; Esch, J.H. van; Ruitenbeek, J.M. van; Thijssen, J.M.; Zant, H.S. van der; Dulic, D.

    2013-01-01

    Metal/organic interfaces critically determine the characteristics of molecular electronic devices, because they influence the arrangement of the orbital levels that participate in charge transport. Studies on self-assembled monolayers show molecule-dependent energy-level shifts as well as

  1. Ionization and charge exchange in atom collision with multicharged ion

    International Nuclear Information System (INIS)

    Presnyakov, L.P.; Uskov, D.B.

    1984-01-01

    Single-electron ionization and charge exchange are considered in collisions of an atom with an ion of charge Z> or =3 and at velocities v>Z -1 /sup // 3 . The approach is based on the Keldysh quasiclassical method. The ionization and charge exchange processes are described within the framework of a single formalism. Effects of rotation and translation are taken into account. The calculated total and partial cross sections agree well with the available experimental data. OFF

  2. Charge transfer dynamics from adsorbates to surfaces with single active electron and configuration interaction based approaches

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Raghunathan, E-mail: r.ramakrishnan@unibas.ch [Institute of Physical Chemistry, National Center for Computational Design and Discovery of Novel Materials (MARVEL), Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel (Switzerland); Nest, Mathias [Theoretische Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching (Germany)

    2015-01-13

    Highlights: • We model electron dynamics across cyano alkanethiolates attached to gold cluster. • We present electron transfer time scales from TD-DFT and TD-CI based simulations. • Both DFT and CI methods qualitatively predict the trend in time scales. • TD-CI predicts the experimental relative time scale very accurately. - Abstract: We employ wavepacket simulations based on many-body time-dependent configuration interaction (TD-CI), and single active electron theories, to predict the ultrafast molecule/metal electron transfer time scales, in cyano alkanethiolates bonded to model gold clusters. The initial states represent two excited states where a valence electron is promoted to one of the two virtual π{sup ∗} molecular orbitals localized on the cyanide fragment. The ratio of the two time scales indicate the efficiency of one charge transfer channel over the other. In both our one-and many-electron simulations, this ratio agree qualitatively with each other as well as with the previously reported experimental time scales (Blobner et al., 2012), measured for a macroscopic metal surface. We study the effect of cluster size and the description of electron correlation on the charge transfer process.

  3. Space charge effects: tune shifts and resonances

    International Nuclear Information System (INIS)

    Weng, W.T.

    1986-08-01

    The effects of space charge and beam-beam interactions on single particle motion in the transverse degree of freedom are considered. The space charge force and the resulting incoherent tune shift are described, and examples are given from the AGS and CERN's PSB. Equations of motion are given for resonances in the presence of the space charge force, and particle behavior is examined under resonance and space charge conditions. Resonance phase space structure is described with and without space charge. Uniform and bunched beams are compared. Beam-beam forces and resonances and beam-beam detuning are described. 18 refs., 15 figs

  4. Study of Blood Metabolites Changes of Purebred Ghezel and Crossbred Arkhar Merinos × Ghezel Ewes during Late Pregnancy

    Directory of Open Access Journals (Sweden)

    Leila Ahmadzadeh

    2016-11-01

    Full Text Available Introduction As pregnancy progresses, nutrient requirements of fetus and thereby ewe increases and some changes in the levels of blood metabolites including glucose, cholesterol and total protein may occur. During gestation, maternal tissues contribute to supplying energy that required for fetus resulting in changes of ewe blood metabolites; however other factors such as breed, age, feeding type of ewes during gestation and season may influence them. The study of blood metabolic changes in different phases of reproductive cycle can be helpful in detecting abnormal situations of ewes and preventing of metabolic disorders such as pregnancy toxemia and fatty liver syndrome. There is little information about the effect of different genotypes on blood metabolites and the occurrence of metabolic disorders in late pregnancy. Therefore the aim of the present study was to determine changes in blood metabolites of purebred Ghezel and ArkharMerino× Ghezel crossbred ewes during late pregnancy and effect of crossbreeding of Iranian purebred sheep with Merino sheep on metabolite level changes in these two groups of sheep and study of susceptibility to metabolic disease in late pregnancy. Materials and Methods In the present study, fifty five pregnant Ghezel ewes (36 singles and 15 twins and 34 pregnant crossbred ewes (20 singles and 14 twins were used. Estrus synchronization of all ewes was done using CIDR. CIDR were removed 14 days later and all ewes were injected PMSG intramuscularly and then mated with rams. All of the ewes were grazing in the pasture during pregnancy, but in the last two months of pregnancy, feeding of ewes was manually. Blood samples were collected by vacuum tubes during four hours after feeding from the jugular vein of ewes on 15 days prior to mating period and on days 90, 120 and 140 of the pregnancy. Blood samples were centrifuged with 4000 rpm for 12 minutes to extract blood serum and then sera were frozen in -20oC until further

  5. Removal of uremic retention products by hemodialysis is coupled with indiscriminate loss of vital metabolites.

    Science.gov (United States)

    Zhang, Zhi-Hao; Mao, Jia-Rong; Chen, Hua; Su, Wei; Zhang, Yuan; Zhang, Li; Chen, Dan-Qian; Zhao, Ying-Yong; Vaziri, Nosratola D

    2017-12-01

    Although dialysis ameliorates uremia and fluid and electrolytes disorders, annual mortality rate remains high in dialysis population reflecting its shortcoming in replacing renal function. Unlike the normal kidney, dialysis causes dramatic shifts in volume and composition of body fluids and indiscriminate removal of vital solutes. Present study was undertaken to determine the impact of hemodialysis on plasma metabolites in end-stage renal disease (ESRD) patients. 80 hemodialysis patients and 80 age/gender-matched healthy controls were enrolled in the study. Using ultra performance liquid chromatography-high-definition mass spectrometry, we measured plasma metabolites before, during, and after hemodialysis procedure and in blood entering and leaving the dialysis filter. Principal component analysis revealed significant difference in concentration of 214 metabolites between healthy control and ESRD patients' pre-dialysis plasma (126 increased and 88 reduced in ESRD group). Comparison of post-dialysis with pre-dialysis data revealed significant changes in the 362 metabolites. Among ESI + metabolites 195 decreased and 55 increased and among ESI - metabolites 82 decreased and 30 increased following hemodialysis. Single blood passage through the dialyzer caused significant changes in 323 metabolites. Comparison of ESRD patients' post-hemodialysis with healthy subjects' data revealed marked differences in metabolic profiles. We identified 55 of the 362 differential metabolites including well known uremic toxins, waste products and vital biological compounds. In addition to uremic toxins and waste products hemodialysis removes large number of identified and as-yet un-identified metabolites. Depletion of vital biological compounds by dialysis may contribute to the high morbidity and annual mortality rate in this population. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  6. Charge regulation at semiconductor-electrolyte interfaces.

    Science.gov (United States)

    Fleharty, Mark E; van Swol, Frank; Petsev, Dimiter N

    2015-07-01

    The interface between a semiconductor material and an electrolyte solution has interesting and complex electrostatic properties. Its behavior will depend on the density of mobile charge carriers that are present in both phases as well as on the surface chemistry at the interface through local charge regulation. The latter is driven by chemical equilibria involving the immobile surface groups and the potential determining ions in the electrolyte solution. All these lead to an electrostatic potential distribution that propagate such that the electrolyte and the semiconductor are dependent on each other. Hence, any variation in the charge density in one phase will lead to a response in the other. This has significant implications on the physical properties of single semiconductor-electrolyte interfaces and on the electrostatic interactions between semiconductor particles suspended in electrolyte solutions. The present paper expands on our previous publication (Fleharty et al., 2014) and offers new results on the electrostatics of single semiconductor interfaces as well as on the interaction of charged semiconductor colloids suspended in electrolyte solution. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Differentiation of clobenzorex use from amphetamine abuse using the metabolite 4-hydroxyclobenzorex.

    Science.gov (United States)

    Valtier, S; Cody, J T

    2000-10-01

    Clobenzorex (Asenlix) is an anorectic drug metabolized by the body to amphetamine, thus causing difficulty in the interpretation of amphetamine-positive drug tests. Previous studies have shown the parent drug and several metabolites are excreted in urine. Clobenzorex itself has been detected for as long as 29 h postdose using a detection limit of 1 ng/mL. Despite this fact, several amphetamine-positive samples (> or = 500 ng/mL) contained no detectable clobenzorex. Thus, the absence of clobenzorex in the urine does not exclude the possibility of its use. To more definitively assess the possibility of clobenzorex use, evaluation of another metabolite was considered. One study reported the presence of unidentified hydroxy metabolites of clobenzorex for as long as amphetamine was detected in some subjects. To assess the viability of using a hydroxy metabolite to confirm the use of clobenzorex in samples containing amphetamine, 4-hydroxyclobenzorex was synthesized for this study. This metabolite proved to be easily detected and was typically found at levels higher than amphetamine in amphetamine-positive urines, long after clobenzorex itself was no longer detected. Samples obtained from a controlled single-dose study involving the administration of clobenzorex (30 mg) were analyzed for the presence of the 4-hydroxy metabolite. The analytical procedure used acid hydrolysis followed by liquid-liquid extraction and analysis with gas chromatography-mass spectrometry by monitoring ions at m/z 125, 330, and 364. 4-Hydroxyclobenzorex and its 3-Cl regioisomer were used in the identification and quantitation of the metabolite. Peak concentrations of 4-hydroxyclobenzorex were found at approximately 1:30-5:00 h postdose and ranged from approximately 5705 to 88,410 ng/mL. Most importantly, however, all samples that contained amphetamine at > or = 500 ng/mL also contained detectable amounts of this hydroxy metabolite (LOD 10 ng/mL), making it a valuable tool in differentiating use

  8. Giant plasmon excitation in single and double ionization of C{sub 60} by fast highly charged Si and O ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai-5 (India)

    2007-09-15

    Se have investigated single and double ionization of C{sub 60} molecule in collisions with 2.33 MeV/u Si{sup q+} (q=6-14) and 3.125 MeV/u O{sup q+} (q=5-8) projectiles. The projectile charge state dependence of the single and double ionization yields of C{sub 60} are then compared to those for an ion-atom collision system using Ne gas as a target. A large difference between the gas and the cluster target behaviour was partially explained in terms of a model based on collective excitation namely the giant dipole plasmon resonance (GDPR). The qualitative agreement between the data and GDPR model prediction for single and double ionization signifies the importance of single and double plasmon excitations in the ionization process. A large deviation of the GDPR model for triple and quadruple ionization from the experimental data imply the importance of the other low impact parameter processes such as evaporation, fragmentation and a possible solid-like dynamical screening.

  9. R-Limonene metabolism in humans and metabolite kinetics after oral administration.

    Science.gov (United States)

    Schmidt, Lukas; Göen, Thomas

    2017-03-01

    We studied the R-limonene (LMN) metabolism and elimination kinetics in a human in vivo study. Four volunteers were orally exposed to a single LMN dose of 100-130 µg kg -1 bw. In each case, one pre-exposure and subsequently all 24 h post-exposure urine samples were collected. From two subjects, blood samples were drawn up to 5 h after exposure. The parent compound was analysed in blood using headspace GC-MS. The metabolites cis- and trans-carveol (cCAR), perillyl alcohol (POH), perillic acid (PA), limonene-1,2-diol (LMN-1,2-OH), and limonene-8,9-diol (LMN-8,9-OH) were quantified in both blood and urine using GC-PCI-MS/MS. Moreover, GC-PCI-MS full-scan experiments were applied for identification of unknown metabolites in urine. In both matrices, metabolites reached maximum concentrations 1-2 h post-exposure followed by rapid elimination with half-lives of 0.7-2.5 h. In relation to the other metabolites, LMN-1,2-OH was eliminated slowest. Nonetheless, overall renal metabolite elimination was completed within the 24-h observation period. The metabolite amounts excreted via urine corresponded to 0.2 % (cCAR), 0.2 % (tCAR), <0.1 % (POH), 2.0 % (PA), 4.3 % (LMN-1,2-OH), and 32 % (LMN-8,9-OH) of the orally administered dose. GC-PCI-MS full-scan analyses revealed dihydroperillic acid (DHPA) as an additional LMN metabolite. DHPA was estimated to account for 5 % of the orally administered dose. The study revealed that human LMN metabolism proceeds fast and is characterised by oxidation mainly of the exo-cyclic double bond but also of the endo-cyclic double bond and of the methyl side chain. The study results may support the prediction of the metabolism of other terpenes or comparable chemical structures.

  10. Transportable hyperpolarized metabolites

    Science.gov (United States)

    Ji, Xiao; Bornet, Aurélien; Vuichoud, Basile; Milani, Jonas; Gajan, David; Rossini, Aaron J.; Emsley, Lyndon; Bodenhausen, Geoffrey; Jannin, Sami

    2017-01-01

    Nuclear spin hyperpolarization of 13C-labelled metabolites by dissolution dynamic nuclear polarization can enhance the NMR signals of metabolites by several orders of magnitude, which has enabled in vivo metabolic imaging by MRI. However, because of the short lifetime of the hyperpolarized magnetization (typically <1 min), the polarization process must be carried out close to the point of use. Here we introduce a concept that markedly extends hyperpolarization lifetimes and enables the transportation of hyperpolarized metabolites. The hyperpolarized sample can thus be removed from the polarizer and stored or transported for use at remote MRI or NMR sites. We show that hyperpolarization in alanine and glycine survives 16 h storage and transport, maintaining overall polarization enhancements of up to three orders of magnitude. PMID:28072398

  11. Microsomal metabolism of trenbolone acetate metabolites ...

    Science.gov (United States)

    Trenbolone acetate (TBA) is a synthetic growth promoter widely used in animal agriculture, and its metabolites are suspected endocrine disrupting compounds in agriculturally impacted receiving waters. However, beyond the three widely recognized TBA metabolites (17-trenbolone, 17-trenbolone and trendione), little is known about other metabolites formed in vivo and subsequently discharged into the environment, with some evidence suggesting these unknown metabolites comprise a majority of the TBA mass dosed to the animal. Here, we explored the metabolism of the three known TBA metabolites using rat liver microsome studies. All TBA metabolites are transformed into a complex mixture of monohydroxylated products. Based on product characterization, the majority are more polar than the parent metabolites but maintain their characteristic trienone backbone. A minor degree of interconversion between known metabolites was also observed, as were higher order hydroxylated products with a greater extent of reaction. Notably, the distribution and yield of products were generally comparable across a series of variably induced rat liver microsomes, as well as during additional studies with human and bovine liver microsomes. Bioassays conducted with mixtures of these transformation products suggest that androgen receptor (AR) binding activity is diminished as a result of the microsomal treatment, suggesting that the transformation products are generally less potent than

  12. Controlling Chain Conformations of High-k Fluoropolymer Dielectrics to Enhance Charge Mobilities in Rubrene Single-Crystal Field-Effect Transistors.

    Science.gov (United States)

    Adhikari, Jwala M; Gadinski, Matthew R; Li, Qi; Sun, Kaige G; Reyes-Martinez, Marcos A; Iagodkine, Elissei; Briseno, Alejandro L; Jackson, Thomas N; Wang, Qing; Gomez, Enrique D

    2016-12-01

    A novel photopatternable high-k fluoropolymer, poly(vinylidene fluoride-bromotrifluoroethylene) P(VDF-BTFE), with a dielectric constant (k) between 8 and 11 is demonstrated in thin-film transistors. Crosslinking P(VDF-BTFE) reduces energetic disorder at the dielectric-semiconductor interface by controlling the chain conformations of P(VDF-BTFE), thereby leading to approximately a threefold enhancement in the charge mobility of rubrene single-crystal field-effect transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Identifying diseases-related metabolites using random walk.

    Science.gov (United States)

    Hu, Yang; Zhao, Tianyi; Zhang, Ningyi; Zang, Tianyi; Zhang, Jun; Cheng, Liang

    2018-04-11

    Metabolites disrupted by abnormal state of human body are deemed as the effect of diseases. In comparison with the cause of diseases like genes, these markers are easier to be captured for the prevention and diagnosis of metabolic diseases. Currently, a large number of metabolic markers of diseases need to be explored, which drive us to do this work. The existing metabolite-disease associations were extracted from Human Metabolome Database (HMDB) using a text mining tool NCBO annotator as priori knowledge. Next we calculated the similarity of a pair-wise metabolites based on the similarity of disease sets of them. Then, all the similarities of metabolite pairs were utilized for constructing a weighted metabolite association network (WMAN). Subsequently, the network was utilized for predicting novel metabolic markers of diseases using random walk. Totally, 604 metabolites and 228 diseases were extracted from HMDB. From 604 metabolites, 453 metabolites are selected to construct the WMAN, where each metabolite is deemed as a node, and the similarity of two metabolites as the weight of the edge linking them. The performance of the network is validated using the leave one out method. As a result, the high area under the receiver operating characteristic curve (AUC) (0.7048) is achieved. The further case studies for identifying novel metabolites of diabetes mellitus were validated in the recent studies. In this paper, we presented a novel method for prioritizing metabolite-disease pairs. The superior performance validates its reliability for exploring novel metabolic markers of diseases.

  14. Evaluation of single and joint toxic effects of diuron and its main metabolites on natural phototrophic biofilms using a pollution-induced community tolerance (PICT) approach.

    Science.gov (United States)

    Pesce, Stéphane; Lissalde, Sophie; Lavieille, Delphine; Margoum, Christelle; Mazzella, Nicolas; Roubeix, Vincent; Montuelle, Bernard

    2010-09-15

    This study assessed the single and joint acute toxicity of diuron and two of its metabolites (DCPMU and 3,4-DCA) on natural phototrophic biofilms using a PICT approach with photosynthesis bioassays. River biofilm communities were collected at three sampling stations exhibiting increasing concentrations of diuron, DCPMU and 3,4-DCA from upstream to downstream. Applied individually, the parent compound was more toxic than its metabolites, with DCPMU being more toxic than 3,4-DCA which only inhibited photosynthesis at very high concentrations (EC25 at about 5 mg/l). Sensitivity of biofilm communities to diuron and DCPMU decreased from upstream to downstream, revealing tolerance induction in contaminated sections of the river, as expected from the PICT concept. Nevertheless, PICT was not applicable for 3,4-DCA, which similarly affected upstream, intermediate and downstream biofilm communities. Chemical mixtures of diuron and DCPMU demonstrated additive effects whereas combinations with 3,4-DCA enhanced the observed effects. Our results reveal that the individual and combined presence of diuron and DCPMU in lotic ecosystems can have both short-term effects (as shown with bioassays) and long-term effects (as shown through the PICT approach) on phototrophic biofilms, whereas environmental concentrations of 3,4-DCA may not affect biofilm photosynthetic activity. 2010 Elsevier B.V. All rights reserved.

  15. Tocopherol metabolites 2, 5, 7, 8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman (alpha-CEHC) and 2, 7, 8-trimethyl-2-(2'-carboxyethyl)-6-hydroxychroman (gamma-CEHC) in human serum after a single dose of natural vitamin E.

    Science.gov (United States)

    Radosavac, Dragan; Graf, Peter; Polidori, M Cristina; Sies, Helmut; Stahl, Wilhelm

    2002-06-01

    alpha- and gamma-Tocopherol are vitamin E compounds in human blood and tissues. alpha-CEHC (2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman) and gamma-CEHC (2,7,8-trimethyl-2-(2'-carboxyethyl)-6-hydroxychroman) have been identified as water-soluble metabolites which are excreted with the urine in humans. To assess over-time changes of serum levels of alpha- and gamma-CEHC in humans after a single dose of vitamin E from a natural source. Twenty-one healthy subjects ingested a single dose of vitamin E (306 mg of RRR-alpha-tocopherol and 1.77 mg of gamma-tocopherol). Blood was collected before (baseline) and 2, 6, 12, 24, 35, 50, and 74 h after ingestion. Serum was separated and levels of alpha- and gamma-tocopherol and alpha- and gamma-CEHC were determined by HPLC. After vitamin E ingestion, a statistically significant increase was observed for alpha-tocopherol and alpha-CEHC. Maximum serum levels for both compounds were measured 12 h after application (33.3 +/- 11.1 micromol alpha-toco-pherol /L and 42.4 +/- 18.3 nmol alpha-CEHC /L); baseline values were reached again after 72 h. While gamma-tocopherol levels decreased during the study period, an increase in the metabolite gamma-CEHC was observed. The optical isomer formed in the metabolism of RRR-alpha-tocopherol was assigned as S-alpha-CEHC. alpha-CEHC levels increase after administration of a single dose of natural vitamin E in humans. The appearance of the metabolite in blood parallels that of the parent compound. The gamma-tocopherol analog appears to be metabolized more efficiently than alpha-tocopherol.

  16. Bayesian deconvolution and quantification of metabolites in complex 1D NMR spectra using BATMAN.

    Science.gov (United States)

    Hao, Jie; Liebeke, Manuel; Astle, William; De Iorio, Maria; Bundy, Jacob G; Ebbels, Timothy M D

    2014-01-01

    Data processing for 1D NMR spectra is a key bottleneck for metabolomic and other complex-mixture studies, particularly where quantitative data on individual metabolites are required. We present a protocol for automated metabolite deconvolution and quantification from complex NMR spectra by using the Bayesian automated metabolite analyzer for NMR (BATMAN) R package. BATMAN models resonances on the basis of a user-controllable set of templates, each of which specifies the chemical shifts, J-couplings and relative peak intensities for a single metabolite. Peaks are allowed to shift position slightly between spectra, and peak widths are allowed to vary by user-specified amounts. NMR signals not captured by the templates are modeled non-parametrically by using wavelets. The protocol covers setting up user template libraries, optimizing algorithmic input parameters, improving prior information on peak positions, quality control and evaluation of outputs. The outputs include relative concentration estimates for named metabolites together with associated Bayesian uncertainty estimates, as well as the fit of the remainder of the spectrum using wavelets. Graphical diagnostics allow the user to examine the quality of the fit for multiple spectra simultaneously. This approach offers a workflow to analyze large numbers of spectra and is expected to be useful in a wide range of metabolomics studies.

  17. Graphene nano-ink biosensor arrays on a microfluidic paper for multiplexed detection of metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Labroo, Pratima; Cui, Yue, E-mail: yue.cui@usu.edu

    2014-02-01

    Graphical abstract: - Highlights: • We report graphene-ink biosensor arrays on a microfluidic paper for metabolites. • The device is able to detect multiple metabolites sensitively and rapidly. • The device fabrication process is simple and inexpensive. - Abstract: The development of a miniaturized and low-cost platform for the highly sensitive, selective and rapid detection of multiplexed metabolites is of great interest for healthcare, pharmaceuticals, food science, and environmental monitoring. Graphene is a delicate single-layer, two-dimensional network of carbon atoms with extraordinary electrical sensing capability. Microfluidic paper with printing technique is a low cost matrix. Here, we demonstrated the development of graphene-ink based biosensor arrays on a microfluidic paper for the multiplexed detection of different metabolites, such as glucose, lactate, xanthine and cholesterol. Our results show that the graphene biosensor arrays can detect multiple metabolites on a microfluidic paper sensitively, rapidly and simultaneously. The device exhibits a fast measuring time of less than 2 min, a low detection limit of 0.3 μM, and a dynamic detection range of 0.3–15 μM. The process is simple and inexpensive to operate and requires a low consumption of sample volume. We anticipate that these results could open exciting opportunities for a variety of applications.

  18. Collisional charging of individual submillimeter particles: Using ultrasonic levitation to initiate and track charge transfer

    Science.gov (United States)

    Lee, Victor; James, Nicole M.; Waitukaitis, Scott R.; Jaeger, Heinrich M.

    2018-03-01

    Electrostatic charging of insulating fine particles can be responsible for numerous phenomena ranging from lightning in volcanic plumes to dust explosions. However, even basic aspects of how fine particles become charged are still unclear. Studying particle charging is challenging because it usually involves the complexities associated with many-particle collisions. To address these issues, we introduce a method based on acoustic levitation, which makes it possible to initiate sequences of repeated collisions of a single submillimeter particle with a flat plate, and to precisely measure the particle charge in situ after each collision. We show that collisional charge transfer between insulators is dependent on the hydrophobicity of the contacting surfaces. We use glass, which we modify by attaching nonpolar molecules to the particle, the plate, or both. We find that hydrophilic surfaces develop significant positive charges after contacting hydrophobic surfaces. Moreover, we demonstrate that charging between a hydrophilic and a hydrophobic surface is suppressed in an acidic environment and enhanced in a basic one. Application of an electric field during each collision is found to modify the charge transfer, again depending on surface hydrophobicity. We discuss these results within the context of contact charging due to ion transfer, and we show that they lend strong support to O H- ions as the charge carriers.

  19. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

    Science.gov (United States)

    Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

    2015-01-01

    Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds. PMID:26364643

  20. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

    Directory of Open Access Journals (Sweden)

    Mariana Greco

    2015-09-01

    Full Text Available Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60% were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%. These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.

  1. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs.

    Science.gov (United States)

    Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

    2015-09-02

    Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.

  2. Chiral Plasma Pharmacokinetics of 3,4-Methylenedioxymethamphetamine and its Phase I and II Metabolites following Controlled Administration to Humans.

    OpenAIRE

    Steuer Andrea E; Schmidhauser Corina; Schmid Yasmin; Rickli Anna; Liechti Matthias E; Kraemer Thomas

    2015-01-01

    Generally, pharmacokinetic studies on 3,4-methylenedioxymethamphetamine (MDMA) in blood have been performed after conjugate cleavage, without taking into account that phase II metabolites represent distinct chemical entities with their own effects and stereoselective pharmacokinetics. The aim of the present study was to stereoselectively investigate the pharmacokinetics of intact glucuronide and sulfate metabolites of MDMA in blood plasma after a controlled single MDMA dose. Plasma samples fr...

  3. Nested Penning Trap as a Source of Singly Charged Ions

    International Nuclear Information System (INIS)

    Ordonez, C.A.

    2003-01-01

    In the work reported, the possibility of using a nested Penning trap as a high purity source of low-charge-state ions is studied. For the configuration considered, a relatively dense ion plasma is confined by a three-dimensional electric potential well. The three-dimensional well is produced by the electric field generated by both the trap electrodes and a trapped electron plasma. The ion and electron plasmas are each considered to have Maxwellian velocity distributions. However, it is shown that the electron plasma must have a temperature that is higher than that of the ion plasma when the ions have low charge states. The work reported includes a self-consistent prediction of a possible plasma equilibrium

  4. Single-cell MALDI-MS as an analytical tool for studying intrapopulation metabolic heterogeneity of unicellular organisms.

    Science.gov (United States)

    Amantonico, Andrea; Urban, Pawel L; Fagerer, Stephan R; Balabin, Roman M; Zenobi, Renato

    2010-09-01

    Heterogeneity is a characteristic feature of all populations of living organisms. Here we make an attempt to validate a single-cell mass spectrometric method for detection of changes in metabolite levels occurring in populations of unicellular organisms. Selected metabolites involved in central metabolism (ADP, ATP, GTP, and UDP-Glucose) could readily be detected in single cells of Closterium acerosum by means of negative-mode matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). The analytical capabilities of this approach were characterized using standard compounds. The method was then used to study populations of individual cells with different levels of the chosen metabolites. With principal component analysis and support vector machine algorithms, it was possible to achieve a clear separation of individual C. acerosum cells in different metabolic states. This study demonstrates the suitability of mass spectrometric analysis of metabolites in single cells to measure cell-population heterogeneity.

  5. Search for free fractional charge

    International Nuclear Information System (INIS)

    Heilig, S.J.

    1985-01-01

    Recent results of searches for free fractional charge have been null with the exception of the experiment at Stanford under the leadership of W. Fairbank. His experiment, while claiming the observation of free fractional charge, has yet to show that this observation was not spurious. The need for a confirming experiment with a different physical system is the motivation for the current work. A torsional pendulum has been constructed of a fused silica fiber with an attached fused silica crossbar. A transverse electric field is applied to the end of the crossbar, and the resulting deflection of the crossbar is used to measure the torque applied by the field. To date the limit of measurement for the charge on the crossbar (without sample) is 0 +/- 24 electronic charges. The history of this experiment is discussed, along with plans for pushing the limits of measurement to below the single-charge level

  6. Prioritizing Candidate Disease Metabolites Based on Global Functional Relationships between Metabolites in the Context of Metabolic Pathways

    Science.gov (United States)

    Yang, Haixiu; Xu, Yanjun; Han, Junwei; Li, Jing; Su, Fei; Zhang, Yunpeng; Zhang, Chunlong; Li, Dongguo; Li, Xia

    2014-01-01

    Identification of key metabolites for complex diseases is a challenging task in today's medicine and biology. A special disease is usually caused by the alteration of a series of functional related metabolites having a global influence on the metabolic network. Moreover, the metabolites in the same metabolic pathway are often associated with the same or similar disease. Based on these functional relationships between metabolites in the context of metabolic pathways, we here presented a pathway-based random walk method called PROFANCY for prioritization of candidate disease metabolites. Our strategy not only takes advantage of the global functional relationships between metabolites but also sufficiently exploits the functionally modular nature of metabolic networks. Our approach proved successful in prioritizing known metabolites for 71 diseases with an AUC value of 0.895. We also assessed the performance of PROFANCY on 16 disease classes and found that 4 classes achieved an AUC value over 0.95. To investigate the robustness of the PROFANCY, we repeated all the analyses in two metabolic networks and obtained similar results. Then we applied our approach to Alzheimer's disease (AD) and found that a top ranked candidate was potentially related to AD but had not been reported previously. Furthermore, our method was applicable to prioritize the metabolites from metabolomic profiles of prostate cancer. The PROFANCY could identify prostate cancer related-metabolites that are supported by literatures but not considered to be significantly differential by traditional differential analysis. We also developed a freely accessible web-based and R-based tool at http://bioinfo.hrbmu.edu.cn/PROFANCY. PMID:25153931

  7. Electro-optical detection of charged particles

    International Nuclear Information System (INIS)

    Semertzidis, Y.K.; Castillo, V.; Kowalski, L.; Kraus, D.E.; Larsen, R.; Lazarus, D.M.; Magurno, B.; Nikas, D.; Ozben, C.; Srinivasan-Rao, T.; Tsang, T.

    2000-01-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO 3 crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams

  8. Electro-optical detection of charged particles

    CERN Document Server

    Semertzidis, Y K; Kowalski, L A; Kraus, D E; Larsen, R; Lazarus, D M; Magurno, B; Nikas, D; Ozben, C; Srinivasan-Rao, T; Tsang, Thomas

    2000-01-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO sub 3 crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams.

  9. Electro-optical detection of charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Semertzidis, Y.K.; Castillo, V.; Kowalski, L.; Kraus, D.E.; Larsen, R.; Lazarus, D.M. E-mail: lazarus@sun2.bnl.gov; Magurno, B.; Nikas, D.; Ozben, C.; Srinivasan-Rao, T.; Tsang, T

    2000-10-01

    We have made the first observation of a charged particle beam by means of its electro-optical effect on the polarization of laser light in a LiNbO{sub 3} crystal. The modulation of the laser light during the passage of a pulsed electron beam was observed using a fast photodiode and a digital oscilloscope. The fastest rise time measured, 120 ps, was obtained in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. This technology holds good for detectors of greatly improved spatial and temporal resolution for single relativistic charged particles as well as particle beams.

  10. 7 CFR 98.5 - Fees and charges.

    Science.gov (United States)

    2010-01-01

    ... MEALS, READY-TO-EAT (MRE's), MEATS, AND MEAT PRODUCTS MRE's, Meats, and Related Meat Food Products § 98.5 Fees and charges. (a) The fee charged for any single laboratory analysis of meat, meat food..., meat food products, and MRE's, not covered by a cooperative agreement, shall result in an additional...

  11. Compound to Extract to Formulation: a knowledge-transmitting approach for metabolites identification of Gegen-Qinlian Decoction, a traditional Chinese medicine formula

    Science.gov (United States)

    Qiao, Xue; Wang, Qi; Wang, Shuang; Miao, Wen-juan; Li, Yan-jiao; Xiang, Cheng; Guo, De-an; Ye, Min

    2016-01-01

    Herbal medicines usually contain a large group of chemical components, which may be transformed into more complex metabolites in vivo. In this study, we proposed a knowledge-transmitting strategy for metabolites identification of compound formulas. Gegen-Qinlian Decoction (GQD) is a classical formula in traditional Chinese medicine (TCM). It is widely used to treat diarrhea and diabetes in clinical practice. However, only tens of metabolites could be detected using conventional approaches. To comprehensively identify the metabolites of GQD, a “compound to extract to formulation” strategy was established in this study. The metabolic pathways of single representative constituents in GQD were studied, and the metabolic rules were transmitted to chemically similar compounds in herbal extracts. After screening diversified metabolites from herb extracts, the knowledge was summarized to identify the metabolites of GQD. Tandem mass spectrometry (MSn), fragment-based scan (NL, PRE), and selected reaction monitoring (SRM) were employed to identify, screen, and monitor the metabolites, respectively. Using this strategy, we detected 131 GQD metabolites (85 were newly generated) in rats biofluids. Among them, 112 metabolites could be detected when GQD was orally administered at a clinical dosage (12.5 g/kg). This strategy could be used for systematic metabolites identification of complex Chinese medicine formulas. PMID:27996040

  12. Maximum entropy theory of recoil charge distributions in electron-capture collisions

    International Nuclear Information System (INIS)

    Aberg, T.; Blomberg, A.; Tulkki, J.; Goscinski, O.

    1984-01-01

    A generalized Fermi-Dirac distribution is derived and applied to charge-state distributions in single collisions between multiply charged ions and rare-gas atoms. It relates multiple electron loss in single-electron capture to multiple ionization in multiphoton absorption and discloses inner-shell vacancy formation in double- and triple-electron capture

  13. Charge-Spot Model for Electrostatic Forces in Simulation of Fine Particulates

    Science.gov (United States)

    Walton, Otis R.; Johnson, Scott M.

    2010-01-01

    The charge-spot technique for modeling the static electric forces acting between charged fine particles entails treating electric charges on individual particles as small sets of discrete point charges, located near their surfaces. This is in contrast to existing models, which assume a single charge per particle. The charge-spot technique more accurately describes the forces, torques, and moments that act on triboelectrically charged particles, especially image-charge forces acting near conducting surfaces. The discrete element method (DEM) simulation uses a truncation range to limit the number of near-neighbor charge spots via a shifted and truncated potential Coulomb interaction. The model can be readily adapted to account for induced dipoles in uncharged particles (and thus dielectrophoretic forces) by allowing two charge spots of opposite signs to be created in response to an external electric field. To account for virtual overlap during contacts, the model can be set to automatically scale down the effective charge in proportion to the amount of virtual overlap of the charge spots. This can be accomplished by mimicking the behavior of two real overlapping spherical charge clouds, or with other approximate forms. The charge-spot method much more closely resembles real non-uniform surface charge distributions that result from tribocharging than simpler approaches, which just assign a single total charge to a particle. With the charge-spot model, a single particle may have a zero net charge, but still have both positive and negative charge spots, which could produce substantial forces on the particle when it is close to other charges, when it is in an external electric field, or when near a conducting surface. Since the charge-spot model can contain any number of charges per particle, can be used with only one or two charge spots per particle for simulating charging from solar wind bombardment, or with several charge spots for simulating triboelectric charging

  14. Discrete stochastic charging of aggregate grains

    Science.gov (United States)

    Matthews, Lorin S.; Shotorban, Babak; Hyde, Truell W.

    2018-05-01

    Dust particles immersed in a plasma environment become charged through the collection of electrons and ions at random times, causing the dust charge to fluctuate about an equilibrium value. Small grains (with radii less than 1 μm) or grains in a tenuous plasma environment are sensitive to single additions of electrons or ions. Here we present a numerical model that allows examination of discrete stochastic charge fluctuations on the surface of aggregate grains and determines the effect of these fluctuations on the dynamics of grain aggregation. We show that the mean and standard deviation of charge on aggregate grains follow the same trends as those predicted for spheres having an equivalent radius, though aggregates exhibit larger variations from the predicted values. In some plasma environments, these charge fluctuations occur on timescales which are relevant for dynamics of aggregate growth. Coupled dynamics and charging models show that charge fluctuations tend to produce aggregates which are much more linear or filamentary than aggregates formed in an environment where the charge is stationary.

  15. Charge-state correlated cross sections for the production of low-velocity highly charged Ne ions by heavy-ion bombardment

    International Nuclear Information System (INIS)

    Gray, T.J.; Cocke, C.L.; Justiniano, E.

    1980-01-01

    We report measured cross sections for the collisional production of highly charged low-velocity Ne recoil ions resulting from the bombardment of a thin Ne gas target by highly charged 1-MeV/amu C, N, O, and F projectiles. The measurements were made using time-of-flight techniques which allowed the simultaneous identification of the final charge state of both the low-velocity recoil ion and the high-velocity projectile for each collision event. For a given incident-projectile charge state, the recoil charge-state distribution is very dependent upon the final charge state of the projectile. Single- and double-electron capture events by incident bare nuclei and projectile K-shell ionization during the collision cause large shifts in the recoil charge-state distributions toward higher charge states. A previously proposed energy-deposition model is modified to include the effects of projectile charge-changing collisions during the collision for bare and hydrogenlike projectiles and is used to discuss the present experimental results

  16. Synthesis of Linezolid Metabolites PNU-142300 and PNU-142586 toward the Exploration of Metabolite-Related Events.

    Science.gov (United States)

    Hanaya, Kengo; Matsumoto, Kazuaki; Yokoyama, Yuta; Kizu, Junko; Shoji, Mitsuru; Sugai, Takeshi

    2017-01-01

    Linezolid (1) is an oxazolidinone antibiotic that is partially metabolized in vivo via ring cleavage of its morpholine moiety to mainly form two metabolites, PNU-142300 (2) and PNU-142586 (3). It is supposed that accumulation of 2 and 3 in patients with renal insufficiency may cause thrombocytopenia, one of the adverse effects of linezolid. However, the poor availability of 2 and 3 has hindered further investigation of the clinical significance of the accumulation of these metabolites. In this paper, we synthesized metabolites 2 and 3 via a common synthetic intermediate, 4; this will encourage further exploration of events related to these metabolites and lead to improved clinical use of linezolid.

  17. [11C]Flumazenil metabolite measurement in plasma is not necessary for accurate brain benzodiazepine receptor quantification

    International Nuclear Information System (INIS)

    Sanabria-Bohorquez, S.M.; Veraart, C.; Labar, D.; Bol, A.; Volder, A.G. de; Michel, C.; Leveque, P.

    2000-01-01

    In this work, a mathematical correction for metabolites has been validated which estimates the relative amount of [ 11 C]flumazenil ([ 11 C]FMZ) in the total plasma curve from the tissue kinetic data without the need for direct metabolite measurement in blood plasma samples. Kinetic data were obtained using a 90-min three-injection protocol on five normal volunteers. First, the relative amount of [ 11 C]FMZ in plasma was modelled by a two-parameter exponential function. The parameters were estimated either directly by fitting this model to the blood plasma metabolite measurements, or indirectly from the simultaneous fitting of tissue time activity curves from several brain regions with a non-linear FMZ kinetic model. Second, the direct and indirect metabolite corrections were fixed and the FMZ compartmental parameters were determined on a regional basis in the brain. The validation was performed by comparing the regional values of benzodiazepine receptor density B max and equilibrium dissociation constant K d obtained with the direct metabolite correction with those values obtained with the indirect correction. For B max , the correlation coefficient r 2 was above 0.97 for all subjects and the slope values of the linear regression were within the interval [0.97, 1.2]. For K d , r 2 was above 0.96, and the slope values of the linear regression were within the interval [0.99, 1.1]. Simulation studies were performed in order to evaluate whether this metabolite correction method could be used in a clinical protocol where only a single [ 11 C]FMZ injection and a linear compartmental model are used. The resulting [ 11 C]FMZ distribution volume estimates were found to be linearly correlated with the true values, with r 2 =1.0 and a slope value of 1.1. The mathematical metabolite correction proved to be a feasible and reliable method to estimate the relative amount of [ 11 C]FMZ in plasma and the compartmental model parameters for three-injection protocols. Although

  18. Environmental charges in airline markets

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Fredrik [Goeteborg Univ., Dept. of Economics, Goeteborg (Sweden)

    2002-07-01

    Over the last two decades many airline markets have been deregulated, resulting in increased competition and use of different types of networks. At the same time there has been an intense discussion on environmental taxation of airline traffic. It is likely that an optimal environmental charge and the effects of a charge differ between different types of aviation markets. In this paper, we derive optimal flight (environmental) charges for different types of airline markets. The first type of market is a multiproduct monopoly airline operating either a point-to-point network or a hub-and-spoke network. The optimal charge is shown to be similar in construction to an optimal charge for a monopolist. We also compare the environmental impact of the two types of networks. Given no differences in marginal damages between airports we find that an airline will always choose the network with the highest environmental damages. The second type of market we investigate is a multiproduct duopoly, where two airlines compete in both passengers and flights. The formulation of the optimal charge is similar to the optimal charge of a single product oligopoly. However, we also show that it is, because of strategic effects, difficult to determine the effects of the charge on the number of flights. (Author)

  19. Nanometer-size surface modification produced by single, low energy, highly charged ions

    International Nuclear Information System (INIS)

    Stockli, M.P.

    1994-01-01

    Atomically flat surfaces of insulators have been bombarded with low energy, highly charged ions to search for nanometer-size surface modifications. It is expected that the high electron deficiency of highly charged ions will capture and/or remove many of the insulator's localized electrons when impacting on an insulating surface. The resulting local electron deficiency is expected to locally disintegrate the insulator through a open-quotes Coulomb explosionclose quotes forming nanometer-size craters. Xe ions with charge states between 10+ and 45+ and kinetic energies between 0 and 10 keV/q were obtained from the KSU-CRYEBIS, a CRYogenic Electron Beam Ion Source and directed onto various insulating materials. Mica was favored as target material as atomically flat surfaces can be obtained reliably through cleaving. However, the authors observations with an atomic force microscope have shown that mica tends to defoliate locally rather than disintegrate, most likely due to the small binding forces between adjacent layers. So far the authors measurements indicate that each ion produces one blister if the charge state is sufficiently high. The blistering does not seem to depend very much on the kinetic energy of the ions

  20. Spatio-Temporal Metabolite Profiling of the Barley Germination Process by MALDI MS Imaging.

    Directory of Open Access Journals (Sweden)

    Karin Gorzolka

    Full Text Available MALDI mass spectrometry imaging was performed to localize metabolites during the first seven days of the barley germination. Up to 100 mass signals were detected of which 85 signals were identified as 48 different metabolites with highly tissue-specific localizations. Oligosaccharides were observed in the endosperm and in parts of the developed embryo. Lipids in the endosperm co-localized in dependency on their fatty acid compositions with changes in the distributions of diacyl phosphatidylcholines during germination. 26 potentially antifungal hordatines were detected in the embryo with tissue-specific localizations of their glycosylated, hydroxylated, and O-methylated derivates. In order to reveal spatio-temporal patterns in local metabolite compositions, multiple MSI data sets from a time series were analyzed in one batch. This requires a new preprocessing strategy to achieve comparability between data sets as well as a new strategy for unsupervised clustering. The resulting spatial segmentation for each time point sample is visualized in an interactive cluster map and enables simultaneous interactive exploration of all time points. Using this new analysis approach and visualization tool germination-dependent developments of metabolite patterns with single MS position accuracy were discovered. This is the first study that presents metabolite profiling of a cereals' germination process over time by MALDI MSI with the identification of a large number of peaks of agronomically and industrially important compounds such as oligosaccharides, lipids and antifungal agents. Their detailed localization as well as the MS cluster analyses for on-tissue metabolite profile mapping revealed important information for the understanding of the germination process, which is of high scientific interest.

  1. Identification of drug metabolites in human plasma or serum integrating metabolite prediction, LC-HRMS and untargeted data processing

    NARCIS (Netherlands)

    Jacobs, P.L.; Ridder, L.; Ruijken, M.; Rosing, H.; Jager, N.G.L.; Beijnen, J.H.; Bas, R.R.; Dongen, W.D. van

    2013-01-01

    Background: Comprehensive identification of human drug metabolites in first-in-man studies is crucial to avoid delays in later stages of drug development. We developed an efficient workflow for systematic identification of human metabolites in plasma or serum that combines metabolite prediction,

  2. A new technique for the study of charge transfer in multiply charged ion-ion collisions

    International Nuclear Information System (INIS)

    Shinpaugh, J.L.; Meyer, F.W.; Datz, S.

    1994-01-01

    While large cross sections (>10 -16 cm 2 ) have been predicted for resonant charge transfer in ion-ion collisions, no experimental data exist for multiply charged systems. A novel technique is being developed at the ORNL ECR facility to allow study of symmetric charge exchange in multiply charged ion-ion collisions using a single ion source. Specific intra-beam charge transfer collisions occurring in a well-defined interaction region labeled by negative high voltage are identified and analyzed by electrostatic analysis in combination with ion time-of-flight coincidence detection of the collision products. Center-of-mass collision energies from 400 to 1000 eV are obtained by varying source and labeling-cell voltages. In addition, by the introduction of a target gas into the high-voltage cell, this labeling-voltage method allows measurement of electron-capture and -loss cross sections for ion-atom collisions. Consequently, higher collision energies can be investigated without the requirement of placing the ECR source on a high-voltage platform

  3. General unknown screening procedure for the characterization of human drug metabolites in forensic toxicology: applications and constraints.

    Science.gov (United States)

    Sauvage, François-Ludovic; Picard, Nicolas; Saint-Marcoux, Franck; Gaulier, Jean-Michel; Lachâtre, Gérard; Marquet, Pierre

    2009-09-01

    LC coupled to single (LC-MS) and tandem (LC-MS/MS) mass spectrometry is recognized as the most powerful analytical tools for metabolic studies in drug discovery. In this article, we describe five cases illustrating the utility of screening xenobiotic metabolites in routine analysis of forensic samples using LC-MS/MS. Analyses were performed using a previously published LC-MS/MS general unknown screening (GUS) procedure developed using a hybrid linear IT-tandem mass spectrometer. In each of the cases presented, the presence of metabolites of xenobiotics was suspected after analyzing urine samples. In two cases, the parent drug was also detected and the metabolites were merely useful to confirm drug intake, but in three other cases, metabolite detection was of actual forensic interest. The presented results indicate that: (i) the GUS procedure developed is useful to detect a large variety of drug metabolites, which would have been hardly detected using targeted methods in the context of clinical or forensic toxicology; (ii) metabolite structure can generally be inferred from their "enhanced" product ion scan spectra; and (iii) structure confirmation can be achieved through in vitro metabolic experiments or through the analysis of urine samples from individuals taking the parent drug.

  4. Quasi-resonant K-K charge transfer

    International Nuclear Information System (INIS)

    Hagmann, S.; Cocke, C.L.; Richard, P.; Skutlartz, A.; Kelbch, S.; Schmidt-Boecking, H.; Schuch, R.

    1983-01-01

    The impact parameter dependence, P(b), of single and double K to K charge transfer have been deduced from the coincidences between K-Auger electrons and scattered particles for F 9+ + Ne and F 9+ + Ne collisions at 10 MeV and 4.4 MeV. The 4.4 MeV single K-K transfer probability exhibits oscillations with b. The P(b) for delta-electron emission is also reported. To obtain more details on the mechanism, K-Auger electron-Ne recoil ion coincidences are measured for both F 8+ and F 9+ projectiles. The relative amounts of recoil ions and of satellite and hypersatellite Auger transitions vary substantially with projectile charge state. 11 references, 11 figures

  5. Steady-state metabolite concentrations reflect a balance between maximizing enzyme efficiency and minimizing total metabolite load.

    Directory of Open Access Journals (Sweden)

    Naama Tepper

    Full Text Available Steady-state metabolite concentrations in a microorganism typically span several orders of magnitude. The underlying principles governing these concentrations remain poorly understood. Here, we hypothesize that observed variation can be explained in terms of a compromise between factors that favor minimizing metabolite pool sizes (e.g. limited solvent capacity and the need to effectively utilize existing enzymes. The latter requires adequate thermodynamic driving force in metabolic reactions so that forward flux substantially exceeds reverse flux. To test this hypothesis, we developed a method, metabolic tug-of-war (mTOW, which computes steady-state metabolite concentrations in microorganisms on a genome-scale. mTOW is shown to explain up to 55% of the observed variation in measured metabolite concentrations in E. coli and C. acetobutylicum across various growth media. Our approach, based strictly on first thermodynamic principles, is the first method that successfully predicts high-throughput metabolite concentration data in bacteria across conditions.

  6. Functional metabolite assemblies—a review

    Science.gov (United States)

    Aizen, Ruth; Tao, Kai; Rencus-Lazar, Sigal; Gazit, Ehud

    2018-05-01

    Metabolites are essential for the normal operation of cells and fulfill various physiological functions. It was recently found that in several metabolic disorders, the associated metabolites could self-assemble to generate amyloid-like structures, similar to canonical protein amyloids that have a role in neurodegenerative disorders. Yet, assemblies with typical amyloid characteristics are also known to have physiological function. In addition, many non-natural proteins and peptides presenting amyloidal properties have been used for the fabrication of functional nanomaterials. Similarly, functional metabolite assemblies are also found in nature, demonstrating various physiological roles. A notable example is the structural color formed by guanine crystals or fluorescent crystals in feline eyes responsible for enhanced night vision. Moreover, some metabolites have been used for the in vitro fabrication of functional materials, such as glycine crystals presenting remarkable piezoelectric properties or indigo films used to assemble organic semi-conductive electronic devices. Therefore, we believe that the study of metabolite assemblies is not only important in order to understand their role in normal physiology and in pathology, but also paves a new route in exploring the fabrication of organic, bio-compatible materials.

  7. Novel Sulfur Metabolites of Garlic Attenuate Cardiac Hypertrophy and Remodeling through Induction of Na+/K+-ATPase Expression.

    Science.gov (United States)

    Khatua, Tarak N; Borkar, Roshan M; Mohammed, Soheb A; Dinda, Amit K; Srinivas, R; Banerjee, Sanjay K

    2017-01-01

    Epidemiologic studies show an inverse correlation between garlic consumption and progression of cardiovascular disease. However, the molecular basis for the beneficial effect of garlic on the heart is not known. Therefore, the objective of the present study was to (1) investigate the effect of raw garlic on isoproterenol (Iso) induced cardiac hypertrophy (2) find the active metabolites of garlic responsible for the beneficial effect. Cardiac hypertrophy was induced in rats by subcutaneous single injection of Iso 5 mg kg -1 day -1 for 15 days and the effect of garlic (250 mg/kg/day orally) was evaluated. Garlic metabolites in in vivo were identified by LC/MS study. The effect of garlic and its metabolites were evaluated against hypertrophy in H9C2 cells. Garlic normalized cardiac oxidative stress after Iso administration. Cardiac pathology and mitochondrial enzyme activities were improved in hypertrophy heart after garlic administration. Decreased Na + /K + -ATPase protein level that observed in hypertrophy heart was increased after garlic administration. We identified three garlic metabolites in rat serum. To confirm the role of garlic metabolites on cardiac hypertrophy, Na + /K + -ATPase expression and intracellular calcium levels were measured after treating H9C2 cells with raw garlic and two of its active metabolites, allyl methyl sulfide and allyl methyl sulfoxide. Raw garlic and both metabolites increased Na + /K + -ATPase protein level and decreased intracellular calcium levels and cell size in Iso treated H9C2 cells. This antihypertrophic effect of garlic and its sulfur metabolites were lost in H9C2 cells in presence of Na + /K + -ATPase inhibitor. In conclusion, garlic and its active metabolites increased Na + /K + -ATPase in rat heart, and attenuated cardiac hypertrophy and associated remodeling. Our data suggest that identified new garlic metabolites may be useful for therapeutic intervention against cardiac hypertrophy.

  8. Cross sections for charge change in argon and equilibrium charge states of 3.5 MeV/amu uranium ions passing through argon and carbon targets

    International Nuclear Information System (INIS)

    Perumal, A.N.; Horvat, V.; Watson, R.L.; Peng, Y.; Fruchey, K.S.

    2005-01-01

    Cross sections for single and multiple electron capture and loss were measured for 3.5 MeV/amu uranium ions, traveling in argon gas, as a function of incident charge state. Multiple electron loss in single collisions was found to contribute significantly to the total loss cross section. The measured cross sections were used to determine the average equilibrium charge in argon by three different methods. The resulting charges were in good agreement with each other and with the effective charge calculated from stopping powers. In order to investigate the gas-solid (density) effect on the average equilibrium charge, the charge distributions of 3.5 MeV/amu uranium ions emerging from carbon foils of different thicknesses were measured. It was found that the average equilibrium charge of the uranium ions emerging from the solid is 41% larger than that of the uranium ions emerging from the gas. The energy dependences of the average equilibrium charges for uranium ions exiting carbon and argon targets were examined by combining the present results with previous results of other investigators and compared with the predictions of a semiempirical formula developed recently by Schiwietz and Grande

  9. Application of Fourier-transform ion cyclotron resonance mass spectrometry to metabolic profiling and metabolite identification.

    Science.gov (United States)

    Ohta, Daisaku; Kanaya, Shigehiko; Suzuki, Hideyuki

    2010-02-01

    Metabolomics, as an essential part of genomics studies, intends holistic understanding of metabolic networks through simultaneous analysis of a myriad of both known and unknown metabolites occurring in living organisms. The initial stage of metabolomics was designed for the reproducible analyses of known metabolites based on their comparison to available authentic compounds. Such metabolomics platforms were mostly based on mass spectrometry (MS) technologies enabled by a combination of different ionization methods together with a variety of separation steps including LC, GC, and CE. Among these, Fourier-transform ion cyclotron resonance MS (FT-ICR/MS) is distinguished from other MS technologies by its ultrahigh resolution power in mass to charge ratio (m/z). The potential of FT-ICR/MS as a distinctive metabolomics tool has been demonstrated in nontargeted metabolic profiling and functional characterization of novel genes. Here, we discuss both the advantages and difficulties encountered in the FT-ICR/MS metabolomics studies.

  10. A Search for Free Fractional Electric Charge Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    Halyo, Valerie

    2000-12-04

    A direct search was carried out in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied--about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup -22} particles per nucleon with 95% confidence.

  11. A Search for Free Fractional Electric Charge Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    Halyo, Valerie

    2000-12-04

    A direct search was carried out in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied| about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup -22} particles per nucleon with 95% confidence.

  12. DFT calculations of the charged states of N@C60 and Fe4 single molecule magnets investigated in tunneling spectroscopy

    Science.gov (United States)

    Nossa, Javier; Islam, Fhokrul; Canali, Carlo; Pederson, Mark

    2012-02-01

    For device applications of single molecule magnets (SMMs) in high-density information storage and quantum-state control it is essential that the magnetic properties of the molecules remain stable under the influence of metallic contacts or surface environment. Recent tunneling experiments [1, 2] on N@C60 and Fe4 SMM have shown that these molecules preserve their magnetic characteristics when they are used as the central island of single-electron transistors. Although quantum spin models have been used extensively to study theoretically tunneling spectroscopy of SMMs, it has been shown recently that the orbital degrees of freedom, which is absent in spin models, can significantly affect the tunneling conductance [3]. In this work we present first-principles calculations of the neutral and charged states of N@C60 and Fe4 SMMs, and discuss a strategy to include their properties into a theory of quantum transport. We also present results of the magnetic anisotropy for the different charge states of Fe4 and discuss their relevance for experiments [2] in the sequential tunneling and cotunnelling regimes. [4pt] [1]. N. Roch et al., Phys. Rev. B 83, 081407 (2011). [0pt] [2]. A.S. Zyazin et al., Nano Lett. 10, 3307 (2010). [0pt] [3]. L. Michalak et al., Phys. Rev. Lett. 104, 017202 (2010).

  13. A Single-Phase Transformerless Inverter With Charge Pump Circuit Concept for Grid-Tied PV Applications

    DEFF Research Database (Denmark)

    Ardashir, Jaber Fallah; Sabahi, Mehran; Hosseini, Seyed Hossein

    2017-01-01

    This paper proposes a new single-phase transformerless photovoltaic (PV) inverter for grid-tied PV systems. The topology is derived from the concept of a charge pump circuit in order to eliminate the leakage current. It is composed of four power switches, two diodes, two capacitors, and an LCL...... resonant control strategy is used to control the injected current. The main benefits of the proposed inverter are: the neutral of the grid is directly connected to the negative terminal of the PV panel, so the leakage current is eliminated; its compact size; low cost; the used dc voltage of the proposed...... are presented. Experimental results are presented to confirm both the theoretical analysis and the concept of the proposed inverter. The obtained results clearly validate the performance of the proposed inverter and its practical application in grid-tied PV systems....

  14. Modifications of gallium phosphide single crystals using slow highly charged ions and swift heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    El-Said, A.S., E-mail: elsaid@kfupm.edu.sa [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Wilhelm, R.A.; Heller, R.; Akhmadaliev, Sh.; Schumann, E. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Sorokin, M. [National Research Centre ’Kurchatov Institute’, Kurchatov Square 1, 123182 Moscow (Russian Federation); Facsko, S. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Trautmann, C. [GSI Helmholtz Centre for Heavy Ion Research, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

    2016-09-01

    GaP single crystals were irradiated with slow highly charged ions (HCI) using 114 keV {sup 129}Xe{sup (33–40)+} and with various swift heavy ions (SHI) of 30 MeV I{sup 9+} and 374 MeV–2.2 GeV {sup 197}Au{sup 25+}. The irradiated surfaces were investigated by scanning force microscopy (SFM). The irradiations with SHI lead to nanohillocks protruding from the GaP surfaces, whereas no changes of the surface topography were observed after the irradiation with HCI. This result indicates that a potential energy above 38.5 keV is required for surface nanostructuring of GaP. In addition, strong coloration of the GaP crystals was observed after irradiation with SHI. The effect was stronger for higher energies. This was confirmed by measuring an increased extinction coefficient in the visible light region.

  15. Charges for plastic bags : Motivational and behavioral effects

    NARCIS (Netherlands)

    Jakovcevic, Adriana; Steg, Linda; Mazzeo, Nadia; Caballero, Romina; Franco, Paul; Putrino, Natalia; Favara, Jesica

    2014-01-01

    Two field studies tested the effects of a charge for single-use plastic bags recently implemented in Buenos Aires City, Argentina. Study 1 showed a greater increase in consumers' own bag use after the charge was introduced in supermarkets where the policy was introduced, in comparison to control

  16. Metabolite damage and repair in metabolic engineering design

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jiayi; Jeffryes, James G.; Henry, Christopher S.; Bruner, Steven D.; Hanson, Andrew D.

    2017-11-01

    The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects.

  17. "How much will I get charged for this?" Patient charges for top ten diagnoses in the emergency department.

    Directory of Open Access Journals (Sweden)

    Nolan Caldwell

    Full Text Available We examined the charges, their variability, and respective payer group for diagnosis and treatment of the ten most common outpatient conditions presenting to the Emergency department (ED.We conducted a cross-sectional study of the 2006-2008 Medical Expenditure Panel Survey. Analysis was limited to outpatient visits with non-elderly, adult (years 18-64 patients with a single discharge diagnosis.We studied 8,303 ED encounters, representing 76.6 million visits. Median charges ranged from $740 (95% CI $651-$817 for an upper respiratory infection to $3437 (95% CI $2917-$3877 for a kidney stone. The median charge for all ten outpatient conditions in the ED was $1233 (95% CI $1199- $1268, with a high degree of charge variability. All diagnoses had an interquartile range (IQR greater than $800 with 60% of IQRs greater than $1550.Emergency department charges for common conditions are expensive with high charge variability. Greater acute care charge transparency will at least allow patients and providers to be aware of the emergency department charges patients may face in the current health care system.

  18. Urinary excretion of androgen metabolites, comparison with excretion of radioactive metabolites after injection of [4-14C]testosterone

    International Nuclear Information System (INIS)

    Deslypere, J.P.; Sayed, A.; Vermeulen, A.; Wiers, P.W.

    1981-01-01

    The influence of age on the metabolic pattern of [4- 14 C]testosterone was studied in 20 young and 8 elderly males and compared to the metabolic pattern of endogenous androgens; the latter was also studied in 16 young and 8 elderly women. In both young and elderly males, androsterone and aetiocholanolone glucuronide represent 65% of [4- 14 C]testosterone metabolites: together with their suephoconjugates as well as with 5α- and 5β-androstane-3α, 17β-diol they represent even more than 75% of total urinary metabolites. The 5α/5β ratio of metabolites of [4- 14 C]testosterone was significantly (P 14 C]testosterone metabolites was generally higher than the ratio of metabolites of endogenous androgens, suggesting that the transformation of T to ring A saturated metabolites occurs at least partially in another compartment than the transformation of DHEA to these metabolites. For both [4- 14 C]testosterone and endogenous androgen metabolites we observed a statistically significant reduction of the 5α/5β ratio with age, a general phenomenon in both males and females. This reduction concern also 11-OH-androst-4-ene-3.17-dione metabolism. Neither sex hormone levels, nor specific binding seems to determine this age dependent shift; neither is there convincing evidence for latent hypothyroisism or liver dysfunction in the elderly. An age associated primary decrease of the 5α-reductase activity seems the most likely explanation. (author)

  19. Secondary metabolites in fungus-plant interactions

    Science.gov (United States)

    Pusztahelyi, Tünde; Holb, Imre J.; Pócsi, István

    2015-01-01

    Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed. PMID:26300892

  20. Time-resolved ion beam induced charge collection (TRIBICC) in micro-electronics

    International Nuclear Information System (INIS)

    Schoene, H.; Walsh, D.S.; Sexton, F.W.; Doyle, B.L.; Aurand, J.F.; Dodd, P.E.; Flores, R.S.; Wing, N.

    1998-01-01

    The entire current transient induced by single 12 MeV Carbon ions was measured at a 5GHz analog bandwidth. A focused ion micro-beam was used to acquire multiple single ion transients at multiple locations of a single CMOS transistor. The current transients reveal clear and discernible contributions of drift and diffusive charge collection. Transients measured for drain and off-drain ion strikes compare well to 3D DAVINCI calculations. Estimates are presented for the drift assisted funneling charge collection depth

  1. SPE-NMR metabolite sub-profiling of urine

    NARCIS (Netherlands)

    Jacobs, D.M.; Spiesser, L.; Garnier, M.; Roo, de N.; Dorsten, van F.; Hollebrands, B.; Velzen, van E.; Draijer, R.; Duynhoven, van J.P.M.

    2012-01-01

    NMR-based metabolite profiling of urine is a fast and reproducible method for detection of numerous metabolites with diverse chemical properties. However, signal overlap in the (1)H NMR profiles of human urine may hamper quantification and identification of metabolites. Therefore, a new method has

  2. Metabolite damage and repair in metabolic engineering design.

    Science.gov (United States)

    Sun, Jiayi; Jeffryes, James G; Henry, Christopher S; Bruner, Steven D; Hanson, Andrew D

    2017-11-01

    The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects. Copyright © 2017 International Metabolic Engineering Society. All rights reserved.

  3. Trophic transfer of pyrene metabolites between aquatic invertebrates

    International Nuclear Information System (INIS)

    Carrasco Navarro, V.; Leppänen, M.T.; Kukkonen, J.V.K.; Godoy Olmos, S.

    2013-01-01

    The trophic transfer of pyrene metabolites was studied using Gammarus setosus as a predator and the invertebrates Lumbriculus variegatus and Chironomus riparius as prey. The results obtained by liquid scintillation counting confirmed that the pyrene metabolites produced by the aquatic invertebrates L. variegatus and C. riparius were transferred to G. setosus through the diet. More detailed analyses by liquid chromatography discovered that two of the metabolites produced by C. riparius appeared in the chromatograms of G. setosus tissue extracts, proving their trophic transfer. These metabolites were not present in chromatograms of G. setosus exclusively exposed to pyrene. The present study supports the trophic transfer of PAH metabolites between benthic macroinvertebrates and common species of an arctic amphipod. As some PAH metabolites are more toxic than the parent compounds, the present study raises concerns about the consequences of their trophic transfer and the fate and effects of PAHs in natural environments. - Highlights: ► The trophic transfer of pyrene metabolites between invertebrates was evaluated. ► Biotransformation of pyrene by L. variegatus and C. riparius is different. ► Metabolites produced by L. variegatus and C. riparius are transferred to G. setosus. ► Specifically, two metabolites produced by C. riparius were transferred. - Some of the pyrene metabolites produced by the model invertebrates L. variegatus and C. riparius are transferred to G. setosus through the diet, proving their trophic transfer.

  4. Time resolved ion beam induced charge collection

    International Nuclear Information System (INIS)

    Sexton W, Frederick; Walsh S, David; Doyle L, Barney; Dodd E, Paul

    2000-01-01

    Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved Ion Beam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a -.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ion beam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients

  5. Time resolved ion beam induced charge collection

    Energy Technology Data Exchange (ETDEWEB)

    SEXTON,FREDERICK W.; WALSH,DAVID S.; DOYLE,BARNEY L.; DODD,PAUL E.

    2000-04-01

    Under this effort, a new method for studying the single event upset (SEU) in microelectronics has been developed and demonstrated. Called TRIBICC, for Time Resolved Ion Beam Induced Charge Collection, this technique measures the transient charge-collection waveform from a single heavy-ion strike with a {minus}.03db bandwidth of 5 GHz. Bandwidth can be expanded up to 15 GHz (with 5 ps sampling windows) by using an FFT-based off-line waveform renormalization technique developed at Sandia. The theoretical time resolution of the digitized waveform is 24 ps with data re-normalization and 70 ps without re-normalization. To preserve the high bandwidth from IC to the digitizing oscilloscope, individual test structures are assembled in custom high-frequency fixtures. A leading-edge digitized waveform is stored with the corresponding ion beam position at each point in a two-dimensional raster scan. The resulting data cube contains a spatial charge distribution map of up to 4,096 traces of charge (Q) collected as a function of time. These two dimensional traces of Q(t) can cover a period as short as 5 ns with up to 1,024 points per trace. This tool overcomes limitations observed in previous multi-shot techniques due to the displacement damage effects of multiple ion strikes that changed the signal of interest during its measurement. This system is the first demonstration of a single-ion transient measurement capability coupled with spatial mapping of fast transients.

  6. Controlled assembly and single electron charging of monolayer protected Au144 clusters: an electrochemistry and scanning tunneling spectroscopy study

    Science.gov (United States)

    Bodappa, Nataraju; Fluch, Ulrike; Fu, Yongchun; Mayor, Marcel; Moreno-García, Pavel; Siegenthaler, Hans; Wandlowski, Thomas

    2014-11-01

    Single gold particles may serve as room temperature single electron memory units because of their size dependent electronic level spacing. Here, we present a proof-of-concept study by electrochemically controlled scanning probe experiments performed on tailor-made Au particles of narrow dispersity. In particular, the charge transport characteristics through chemically synthesized hexane-1-thiol and 4-pyridylbenzene-1-thiol mixed monolayer protected Au144 clusters (MPCs) by differential pulse voltammetry (DPV) and electrochemical scanning tunneling spectroscopy (EC-STS) are reported. The pyridyl groups exposed by the Au-MPCs enable their immobilization on Pt(111) substrates. By varying the humidity during their deposition, samples coated by stacks of compact monolayers of Au-MPCs or decorated with individual, laterally separated Au-MPCs are obtained. DPV experiments with stacked monolayers of Au144-MPCs and EC-STS experiments with laterally separated individual Au144-MPCs are performed both in aqueous and ionic liquid electrolytes. Lower capacitance values were observed for individual clusters compared to ensemble clusters. This trend remains the same irrespective of the composition of the electrolyte surrounding the Au144-MPC. However, the resolution of the energy level spacing of the single clusters is strongly affected by the proximity of neighboring particles.Single gold particles may serve as room temperature single electron memory units because of their size dependent electronic level spacing. Here, we present a proof-of-concept study by electrochemically controlled scanning probe experiments performed on tailor-made Au particles of narrow dispersity. In particular, the charge transport characteristics through chemically synthesized hexane-1-thiol and 4-pyridylbenzene-1-thiol mixed monolayer protected Au144 clusters (MPCs) by differential pulse voltammetry (DPV) and electrochemical scanning tunneling spectroscopy (EC-STS) are reported. The pyridyl groups

  7. Direct coupling of electromembrane extraction to mass spectrometry - Advancing the probe functionality toward measurements of zwitterionic drug metabolites.

    Science.gov (United States)

    Rye, Torstein Kige; Fuchs, David; Pedersen-Bjergaard, Stig; Petersen, Nickolaj Jacob

    2017-08-29

    A triple-flow electromembrane extraction (EME) probe was developed and coupled directly to electrospray-ionization mass spectrometry (ESI-MS). Metabolic reaction mixtures (pH 7.4) containing drug substances and related metabolites were continuously drawn (20 μL/min) into the EME probe in one flow channel, and mixed inside the probe with 7.5 μL min -1 of 1 M formic acid as make-up flow from a second flow channel. Following this acidification, the drug substances and their related metabolites were continuously extracted by EME at 400 V, across a supported liquid membrane (SLM) comprising 2-nitrophenyl octyl ether (and for some experiments containing 30% triphenyl phosphate (TPP)), and into 20 μL min -1 of formic acid as acceptor phase, which was introduced through a third flow channel. The acceptor phase was pumped directly to the MS system, and the ion intensity of extracted analytes was followed continuously as function of time. The triple-flow EME probe was used for co-extraction of positively charged parent drugs and their zwitterionic drug metabolites (hydroxyzine and its carboxylic acid metabolite cetirizine; and vortioxetine and its carboxylic acid metabolite Lu AA34443). While the zwitterionic metabolites could not be extracted at pH 7.4, it was shown that by acidifying the sample solution the zwitterionic metabolites could be extracted effectively. Various extraction parameters like make-up flow, extraction voltage and SLM composition were optimized for simultaneous extraction of parent drugs and metabolites. It was found that TPP added to the SLM improved extraction efficiencies of certain drug metabolites. Finally the optimized and characterized triple-flow EME probe was used for online studying the in-vitro metabolism of hydroxyzine and vortioxetine by rat liver microsomes. Due to the automated pre-extraction acidification of the rat liver microsomal solutions, it was possible to continuously monitor formation of the zwitterionic drug

  8. Formation of reactive metabolites from benzene

    International Nuclear Information System (INIS)

    Snyder, R.; Jowa, L.; Witz, G.; Kalf, G.; Rushmore, T.

    1986-01-01

    Rat liver mitoplasts were incubated first with [ 3 H]dGTP, to form DNA labeled in G, and then with [ 14 C]benzene. The DNA was isolated and upon isopycnic density gradient centrifugation in CsCl yielded a single fraction of DNA labeled with both [ 3 H] and [ 14 C]. These data are consistent with the covalent binding of one or more metabolites of benzene to DNA. The DNA was enzymatically hydrolyzed to deoxynucleosides and chromatographed to reveal at least seven deoxyguanosine adducts. Further studies with labeled deoxyadenine revealed one adduct on deoxyadenine. [ 3 H]Deoxyguanosine was reacted with [ 14 C]hydroquinone or benzoquinone. The product was characterized using uv, fluorescence, mass and NMR spectroscopy. A proposed structure is described. (orig.)

  9. Estimation of genetic parameters and detection of quantitative trait loci for metabolites in Danish Holstein milk

    DEFF Research Database (Denmark)

    Buitenhuis, Albert Johannes; Sundekilde, Ulrik; Poulsen, Nina Aagaard

    2013-01-01

    Small components and metabolites in milk are significant for the utilization of milk, not only in dairy food production but also as disease predictors in dairy cattle. This study focused on estimation of genetic parameters and detection of quantitative trait loci for metabolites in bovine milk. F...... for lactic acid to >0.8 for orotic acid and β-hydroxybutyrate. A single SNP association analysis revealed 7 genome-wide significant quantitative trait loci [malonate: Bos taurus autosome (BTA)2 and BTA7; galactose-1-phosphate: BTA2; cis-aconitate: BTA11; urea: BTA12; carnitine: BTA25...

  10. A note on Fenchel cuts for the single-node flow problem

    DEFF Research Database (Denmark)

    Klose, Andreas

    The single-node flow problem, which is also known as the single-sink fixed-charge transportation problem, consists in finding a minimum cost flow from a number of nodes to a single sink. The flow cost comprise an amount proportional to the quantity shipped as well as a fixed charge. In this note......, some structural properties of Fenchel cutting planes for this problem are described. Such cuts might then be applied for solving, e.g., fixed-charge transportation problems and more general fixed-charge network flow problems....

  11. Organic field-effect transistors using single crystals

    International Nuclear Information System (INIS)

    Hasegawa, Tatsuo; Takeya, Jun

    2009-01-01

    Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20-40 cm 2 Vs -1 , achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps. (topical review)

  12. Production of Secondary Metabolites in Extreme Environments: Food- and Airborne Wallemia spp. Produce Toxic Metabolites at Hypersaline Conditions

    DEFF Research Database (Denmark)

    Jančič, Sašo; Frisvad, Jens Christian; Kocev, Dragi

    2016-01-01

    the genome data analysis of W. mellicola (previously W. sebi sensu lato) and W. ichthyophaga revealed a low number of secondary metabolites clusters, a substantial number of secondary metabolites were detected at different conditions. Machine learning analysis of the obtained dataset showed that NaCl has...... of salt or sugar. In relation to food safety, the effect of high salt and sugar concentrations on the production of secondary metabolites by this toxigenic fungus was investigated. The secondary metabolite profiles of 30 strains of the listed species were examined using general growth media, known...... to support the production of secondary metabolites, supplemented with different concentrations of NaCl, glucose and MgCl2. In more than two hundred extracts approximately one hundred different compounds were detected using high-performance liquid chromatography-diode array detection (HPLC-DAD). Although...

  13. Brain metabolite alterations in Eisenmenger syndrome: Evaluation with MR proton spectroscopy

    International Nuclear Information System (INIS)

    Dokumacı, Dilek Şen; Doğan, Ferit; Yıldırım, Ali; Boyacı, Fatıma Nurefşan; Bozdoğan, Erol; Koca, Bülent

    2017-01-01

    Objective: Eisenmenger syndrome (ES) is a life-threatening disease characterized by pulmonary hypertension and cyanosis in patients with congenital heart diseases. The aim of this study was to determine the brain metabolite changes in Eisenmenger syndrome compared with a control group using MR proton spectroscopy. Methods and Materials: The study included 10 children (3 male, 7 female) with congenital heart diseases and a diagnosis of Eisenmenger syndrome. The control group consisted of 10 healthy volunteer children. All were examined with a 1.5 T MRI scanner and single voxel spectroscopy was performed to obtain spectra from three different regions; left frontal subcortical white matter, left lentiform nucleus and left thalamus. Peak integral values obtained from the spectra were used as quantitative data. Results: The ages of the children with ES were between 5 and 16 years, and between 5 and 15 years in the control group. Periventricular white matter hyperintensities were observed in 3 patients. On MR spectroscopy study, significantly lower levels of Choline metabolite (Cho) were detected in the frontal subcortical region and thalamus regions of the patients compared with the control group. There was no statistically significant difference between the levels of other metabolites (NAA, Cr, mI and Glx). In the lentiform nucleus, although the average value of Cho in ES patients was lower than that of the control group, it was not statistically significant. Conclusion: Cho metabolite was determined to have an important role in brain metabolism in Eisenmenger syndrome patients. Oral Cho treatment may help to extend survival.

  14. Brain metabolite alterations in Eisenmenger syndrome: Evaluation with MR proton spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dokumacı, Dilek Şen, E-mail: dileksendokumaci@yahoo.com [Harran University School of Medicine, Department of Radiology, Sanliurfa (Turkey); Doğan, Ferit [Children Hospital, Department of Radiology, Sanliurfa (Turkey); Yıldırım, Ali [Children Hospital, Department of Pediatric Cardiology, Sanliurfa (Turkey); Boyacı, Fatıma Nurefşan; Bozdoğan, Erol [Harran University School of Medicine, Department of Radiology, Sanliurfa (Turkey); Koca, Bülent [Harran University School of Medicine, Department of Pediatric Cardiology, Sanliurfa (Turkey)

    2017-01-15

    Objective: Eisenmenger syndrome (ES) is a life-threatening disease characterized by pulmonary hypertension and cyanosis in patients with congenital heart diseases. The aim of this study was to determine the brain metabolite changes in Eisenmenger syndrome compared with a control group using MR proton spectroscopy. Methods and Materials: The study included 10 children (3 male, 7 female) with congenital heart diseases and a diagnosis of Eisenmenger syndrome. The control group consisted of 10 healthy volunteer children. All were examined with a 1.5 T MRI scanner and single voxel spectroscopy was performed to obtain spectra from three different regions; left frontal subcortical white matter, left lentiform nucleus and left thalamus. Peak integral values obtained from the spectra were used as quantitative data. Results: The ages of the children with ES were between 5 and 16 years, and between 5 and 15 years in the control group. Periventricular white matter hyperintensities were observed in 3 patients. On MR spectroscopy study, significantly lower levels of Choline metabolite (Cho) were detected in the frontal subcortical region and thalamus regions of the patients compared with the control group. There was no statistically significant difference between the levels of other metabolites (NAA, Cr, mI and Glx). In the lentiform nucleus, although the average value of Cho in ES patients was lower than that of the control group, it was not statistically significant. Conclusion: Cho metabolite was determined to have an important role in brain metabolism in Eisenmenger syndrome patients. Oral Cho treatment may help to extend survival.

  15. Secondary metabolites from Ganoderma.

    Science.gov (United States)

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

    2015-06-01

    Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Non-abelian operations on majorana fermions via single-charge control

    DEFF Research Database (Denmark)

    Flensberg, Karsten

    2011-01-01

    similar to braiding, though not in real space. Unlike braiding operations, rotations by a continuum of angles are possible, while still being partially robust against perturbations. The quantum dots can also be used for readout of the state of the Majorana system via a charge measurement....

  17. Single-crystal study of the charge density wave metal LuNiC2

    Science.gov (United States)

    Steiner, S.; Michor, H.; Sologub, O.; Hinterleitner, B.; Höfenstock, F.; Waas, M.; Bauer, E.; Stöger, B.; Babizhetskyy, V.; Levytskyy, V.; Kotur, B.

    2018-05-01

    We report on single-crystal growth, single-crystal x-ray diffraction, physical properties, and density functional theory (DFT) electronic structure as well as Fermi surface calculations for two ternary carbides, LuCoC2 and LuNiC2. Electrical resistivity measurements reveal for LuNiC2 a charge density wave (CDW) transition at TCDW≃450 K and, for T >TCDW , a significant anisotropy of the electrical resistivity, which is lowest along the orthorhombic a axis. The analysis of x-ray superstructure reflections suggest a commensurate CDW state with a Peierls-type distortion of the Ni atom periodicity along the orthorhombic a axis. DFT calculations based on the CDW modulated monoclinic structure model of LuNiC2 as compared to results of the orthorhombic parent type reveal the formation of a partial CDW gap at the Fermi level which reduces the electronic density of states from N (EF)=1.03 states/eV f.u. without CDW to N (EF)=0.46 states/eV f.u. in the CDW state. The corresponding bare DFT Sommerfeld value of the latter, γDFTCDW=0.90 mJ/mol K2, reaches reasonable agreement with the experimental value γ =0.83 (5 ) mJ/mol K2 of LuNiC2. LuCoC2 displays a simple metallic behavior with neither CDW ordering nor superconductivity above 0.4 K. Its experimental Sommerfeld coefficient, γ =5.9 (1) mJ/mol K2, is in realistic correspondence with the calculated, bare Sommerfeld coefficient, γDFT=3.82 mJ/mol K2, of orthorhombic LuCoC2.

  18. In vivo estimation of transverse relaxation time constant (T2 ) of 17 human brain metabolites at 3T.

    Science.gov (United States)

    Wyss, Patrik O; Bianchini, Claudio; Scheidegger, Milan; Giapitzakis, Ioannis A; Hock, Andreas; Fuchs, Alexander; Henning, Anke

    2018-08-01

    The transverse relaxation times T 2 of 17 metabolites in vivo at 3T is reported and region specific differences are addressed. An echo-time series protocol was applied to one, two, or three volumes of interest with different fraction of white and gray matter including a total number of 106 healthy volunteers and acquiring a total number of 128 spectra. The data were fitted with the 2D fitting tool ProFit2, which included individual line shape modeling for all metabolites and allowed the T 2 calculation of 28 moieties of 17 metabolites. The T 2 of 10 metabolites and their moieties have been reported for the first time. Region specific T 2 differences in white and gray matter enriched tissue occur in 16 of 17 metabolites examined including single resonance lines and coupled spin systems. The relaxation time T 2 is regions specific and has to be considered when applying tissue composition correction for internal water referencing. Magn Reson Med 80:452-461, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

  19. Charge changing collision cross sections of atomic ions

    International Nuclear Information System (INIS)

    Bliman, S.; Dousson, S.; Geller, R.; Jacquot, B.; Van Houtte, D.

    1980-05-01

    A device has been built to measure charge changing cross sections of atomic ions. It consists of an E.C.R. ion source (Micromafios) that delivers oxygen ions up to charge + 8, argon ions up to charge + 13. The ion source potential may be varied from 1 up to 10 kVolts. A first magnet is used to charge analyze the extracted beam. For a given charge state, the ion beam is passed in a collision cell whose pressure may be varied. The ions undergoing collisions on the target are analyzed by a second magnet and collected. The single collision condition is checked. Different collisions are considered: 1- Charge exchange collisions of argon ions with charge 2<=Z<=12 on argon. Cross sections for capture of 1, 2 and 3 electrons are given. 2- Stripping of argon ions (1<=Z<=4) on argon atoms. 3- Charge exchange of oxygen ions (2<=Z<=8) colliding on deuterium. One and two electron capture cross sections are presented

  20. Electron beam charge state amplifier (EBQA)--a conceptual evaluation

    International Nuclear Information System (INIS)

    Dooling, J. C.

    1998-01-01

    A concept is presented for stripping low-energy, radioactive ions from 1+ to higher charge states. Referred to as an Electron Beam Charge State Amplifier (EBQA), this device accepts a continuous beam of singly-charged, radioactive ions and passes them through a high-density electron beam confined by a solenoidal magnetic field. Singly-charged ions may be extracted from standard Isotope-Separator-Online (ISOL) sources. An EBQA is potentially useful for increasing the charge state of ions prior to injection into post-acceleration stages at ISOL radioactive beam facilities. The stripping efficiency from q=1+ to 2+ (η 12 ) is evaluated as a function of electron beam radius at constant current with solenoid field, injected ion energy, and ion beam emittance used as parameters. Assuming a 5 keV, 1 A electron beam, η 12 = 0.38 for 0.1 keV, 132 Xe ions passing through an 8 Tesla solenoid, 1 m in length. Multi-pass configurations to achieve 3+ or 4+ charge states are also conceivable. The calculated efficiencies depend inversely on the initial ion beam emittances. The use of a helium-buffer-gas, ion-guide stage to improve the brightness of the 1+ beams [1] may enhance the performance of an EBQA

  1. Effective charge versus bare charge: an analytical estimate for colloids in the infinite dilution limit

    International Nuclear Information System (INIS)

    Aubouy, Miguel; Trizac, Emmanuel; Bocquet, Lyderic

    2003-01-01

    We propose an analytical approximation for the dependence of the effective charge on the bare charge for spherical and cylindrical macro-ions as a function of the size of the colloid and salt content, for the situation of a unique colloid immersed in a sea of electrolyte (where the definition of an effective charge is non-ambiguous). Our approach is based on the Poisson-Boltzmann (PB) mean-field theory. Mathematically speaking, our estimate is asymptotically exact in the limit κa >> 1, where a is the radius of the colloid and κ is the inverse screening length. In practice, a careful comparison with effective charge parameters, obtained by numerically solving the full nonlinear PB theory, proves that our estimate is good down to κa ∼ 1. This is precisely the limit appropriate to treat colloidal suspensions. A particular emphasis is put on the range of parameters suitable to describe both single and double strand DNA molecules under physiological conditions

  2. Enabling fast charging - Vehicle considerations

    Science.gov (United States)

    Meintz, Andrew; Zhang, Jiucai; Vijayagopal, Ram; Kreutzer, Cory; Ahmed, Shabbir; Bloom, Ira; Burnham, Andrew; Carlson, Richard B.; Dias, Fernando; Dufek, Eric J.; Francfort, James; Hardy, Keith; Jansen, Andrew N.; Keyser, Matthew; Markel, Anthony; Michelbacher, Christopher; Mohanpurkar, Manish; Pesaran, Ahmad; Scoffield, Don; Shirk, Matthew; Stephens, Thomas; Tanim, Tanvir

    2017-11-01

    To achieve a successful increase in the plug-in battery electric vehicle (BEV) market, it is anticipated that a significant improvement in battery performance is required to increase the range that BEVs can travel and the rate at which they can be recharged. While the range that BEVs can travel on a single recharge is improving, the recharge rate is still much slower than the refueling rate of conventional internal combustion engine vehicles. To achieve comparable recharge times, we explore the vehicle considerations of charge rates of at least 400 kW. Faster recharge is expected to significantly mitigate the perceived deficiencies for long-distance transportation, to provide alternative charging in densely populated areas where overnight charging at home may not be possible, and to reduce range anxiety for travel within a city when unplanned charging may be required. This substantial increase in charging rate is expected to create technical issues in the design of the battery system and the vehicle's electrical architecture that must be resolved. This work focuses on vehicle system design and total recharge time to meet the goals of implementing improved charge rates and the impacts of these expected increases on system voltage and vehicle components.

  3. Fragmentation of organic ions bearing fixed multiple charges observed in MALDI MS

    NARCIS (Netherlands)

    Lou, X.; Li, B.; de Waal, B.F.M.; Schill, J.; Baker, M.B.; Bovee, R.A.A.; van Dongen, J.L.J.; Milroy, L.G.; Meijer, E.W.

    2018-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) was used to analyze a series of synthetic organic ions bearing fixed multiple charges. Despite the multiple intrinsic charges, only singly charged ions were recorded in each case. In addition to the

  4. Yeast synthetic biology for high-value metabolites.

    Science.gov (United States)

    Dai, Zhubo; Liu, Yi; Guo, Juan; Huang, Luqi; Zhang, Xueli

    2015-02-01

    Traditionally, high-value metabolites have been produced through direct extraction from natural biological sources which are inefficient, given the low abundance of these compounds. On the other hand, these high-value metabolites are usually difficult to be synthesized chemically, due to their complex structures. In the last few years, the discovery of genes involved in the synthetic pathways of these metabolites, combined with advances in synthetic biology tools, has allowed the construction of increasing numbers of yeast cell factories for production of these metabolites from renewable biomass. This review summarizes recent advances in synthetic biology in terms of the use of yeasts as microbial hosts for the identification of the pathways involved in the synthesis, as well as for the production of high-value metabolites. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  5. Optical Pumping of the Electronic and Nuclear Spin of Single Charge-Tunable Quantum Dots

    Science.gov (United States)

    Bracker, A. S.; Stinaff, E. A.; Gammon, D.; Ware, M. E.; Tischler, J. G.; Shabaev, A.; Efros, Al. L.; Park, D.; Gershoni, D.; Korenev, V. L.; Merkulov, I. A.

    2005-02-01

    We present a comprehensive examination of optical pumping of spins in individual GaAs quantum dots as we change the net charge from positive to neutral to negative with a charge-tunable heterostructure. Negative photoluminescence polarization memory is enhanced by optical pumping of ground state electron spins, which we prove with the first measurements of the Hanle effect on an individual quantum dot. We use the Overhauser effect in a high longitudinal magnetic field to demonstrate efficient optical pumping of nuclear spins for all three charge states of the quantum dot.

  6. Charge equilibrium processes of energetic incident ions and their range

    International Nuclear Information System (INIS)

    Kawagoshi, Hiroshi; Karashima, Shosuke; Watanabe, Tsutomu.

    1984-01-01

    The charge state of energetic ions passing through a certain matter is varied by charge-exchange processes. A rate equation for charge fraction is given by using electron loss and capture cross sections in collision with a target atom under idealized condition. We solved the rate equation of the charge-exchange process of a single electron in a form of linear coupled differential equation. Our calcuiation for the range of ion were carried out for He, Ne and Ar ions passing through an atomic hydrogen gas target. We discuss the charge states of the projectile in relation to a local charge balance consituting a state of charge equilibrium in the target. (author)

  7. Mixture toxicity of the antiviral drug Tamiflu (oseltamivir ethylester) and its active metabolite oseltamivir acid

    Energy Technology Data Exchange (ETDEWEB)

    Escher, Beate I., E-mail: b.escher@uq.edu.au [University of Queensland, National Research Centre for Environmental Toxicology (Entox), 39 Kessels Rd, Brisbane, Qld 4108 (Australia); Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Duebendorf (Switzerland); Bramaz, Nadine; Lienert, Judit; Neuwoehner, Judith [Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Duebendorf (Switzerland); Straub, Juerg Oliver [F.Hoffmann-La Roche Ltd, Corporate Safety, Health and Environmental Protection, 4070 Basel (Switzerland)

    2010-02-18

    Tamiflu (oseltamivir ethylester) is an antiviral agent for the treatment of influenza A and B. The pro-drug Tamiflu is converted in the human body to the pharmacologically active metabolite, oseltamivir acid, with a yield of 75%. Oseltamivir acid is indirectly photodegradable and slowly biodegradable in sewage works and sediment/water systems. A previous environmental risk assessment has concluded that there is no bioaccumulation potential of either of the compounds. However, little was known about the ecotoxicity of the metabolite. Ester hydrolysis typically reduces the hydrophobicity and thus the toxicity of a compound. In this case, a zwitterionic, but overall neutral species is formed from the charged parent compound. If the speciation and predicted partitioning into biological membranes is considered, the metabolite may have a relevant contribution to the overall toxicity. These theoretical considerations triggered a study to investigate the toxicity of oseltamivir acid (OA), alone and in binary mixtures with its parent compound oseltamivir ethylester (OE). OE and OA were found to be baseline toxicants in the bioluminescence inhibition test with Vibrio fischeri. Their mixture effect lay between predictions for concentration addition and independent action for the mixture ratio excreted in urine and nine additional mixture ratios of OE and OA. In contrast, OE was an order of magnitude more toxic than OA towards algae, with a more pronounced effect when the direct inhibition of photosystem II was used as toxicity endpoint opposed to the 24 h growth rate endpoint. The binary mixtures in this assay yielded experimental mixture effects that agreed with predictions for independent action. This is consistent with the finding that OE exhibits slightly enhanced toxicity, while OA acts as baseline toxicant. Therefore, with respect to mixture classification, the two compounds can be considered as acting according to different modes of toxic action, although there are

  8. Charged black holes with scalar hair

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhong-Ying; Lü, H. [Center for Advanced Quantum Studies, Department of Physics,Beijing Normal University, Beijing 100875 (China)

    2015-09-10

    We consider a class of Einstein-Maxwell-Dilaton theories, in which the dilaton coupling to the Maxwell field is not the usual single exponential function, but one with a stationary point. The theories admit two charged black holes: one is the Reissner-Nordstrøm (RN) black hole and the other has a varying dilaton. For a given charge, the new black hole in the extremal limit has the same AdS{sub 2}×Sphere near-horizon geometry as the RN black hole, but it carries larger mass. We then introduce some scalar potentials and obtain exact charged AdS black holes. We also generalize the results to black p-branes with scalar hair.

  9. Aquatic toxicity of the macrolide antibiotic clarithromycin and its metabolites.

    Science.gov (United States)

    Baumann, Michaela; Weiss, Klaus; Maletzki, Dirk; Schüssler, Walter; Schudoma, Dieter; Kopf, Willi; Kühnen, Ute

    2015-02-01

    The human macrolide antibiotic clarithromycin is widespread in surface waters. Our study shows that its major metabolite 14-hydroxy(R)-clarithromycin is found in surface waters in comparable amounts. This metabolite is known to be pharmacologically active. Additionally, clarithromycin is partly metabolised to N-desmethyl-clarithromycin, which has no antimicrobial activity. For clarithromycin, some ecotoxicological studies on aquatic organisms have been published. However, many of them are not conform with the scientific principles as given in the "Technical guidance for deriving environmental quality standards" (TGD-EQS), because numerous studies were poorly documented and the methods did not contain analytical measurements confirming that the exposure concentrations were in the range of ± 20% of the nominal concentrations. Ecotoxicological effects of clarithromycin and its two metabolites on the zebrafish Danio rerio (embryo test), the microcrustacean Daphnia magna, the aquatic monocotyledonous macrophyte Lemna minor, the freshwater green alga Desmodesmus subspicatus (Chlorophyta) and the cyanobacterium Anabaena flosaquae were investigated in compliance with the TGD-EQS. Environmental risk assessment was performed using ErC10 values of Anabaena, the species most sensitive to clarithromycin and 14-hydroxy(R)-clarithromycin in our testing. Based oncomparable toxicity and similar concentrations of clarithromycin and its active metabolite 14-hydroxy(R)-clarithromycin in surface waters, an additional multiplication factor of 2 to the assessment factor of 10 on the ErC10 of clarithromycin should be used. Consequently, a freshwater quality standard of 0.130 μg L(-1) is proposed for clarithromycin as the "lead substance". Taking this additional multiplication factor of 2 into account, single monitoring of clarithromycin may be sufficient, in order to reduce the number of substances listed for routine monitoring programs. Copyright © 2014 Elsevier Ltd. All rights

  10. Identification of metabolites of the tryptase inhibitor CRA-9249: observation of a metabolite derived from an unexpected hydroxylation pathway.

    Science.gov (United States)

    Yu, Walter; Dener, Jeffrey M; Dickman, Daniel A; Grothaus, Paul; Ling, Yun; Liu, Liang; Havel, Chris; Malesky, Kimberly; Mahajan, Tania; O'Brian, Colin; Shelton, Emma J; Sperandio, David; Tong, Zhiwei; Yee, Robert; Mordenti, Joyce J

    2006-08-01

    The metabolites of the tryptase inhibitor CRA-9249 were identified after exposure to liver microsomes. CRA-9249 was found to be degraded rapidly in liver microsomes from rabbit, dog, cynomolgus monkey, and human, and less rapidly in microsomes from rat. The key metabolites included cleavage of an aryl ether, in addition to an unexpected hydroxylation of the amide side chain adjacent to the amide nitrogen. The chemical structures of both metabolites were confirmed by synthesis and comparison to material isolated from the liver microsomes. Several suspected hydroxylated metabolites were also synthesized and analyzed as part of the structure identification process.

  11. Ion-atom collisions with laser-prepared target: High resolution study of single charge exchange process

    International Nuclear Information System (INIS)

    Leredde, Arnaud

    2012-01-01

    Single charge transfer in low-energy Na"++"8"7Rb(5s,5p) collisions is investigated using magneto-optically trapped Rb atoms and high-resolution recoil-ion momentum spectroscopy. The three-dimensional reconstruction of the recoil-ion momentum provides accurate relative cross-sections for the active channels and the projectile scattering angle distributions. Thanks to the high experimental resolution, scattering structures such as diffraction-like oscillations in angular distributions are clearly observed. The measurements are compared with molecular close-coupling calculations and an excellent agreement is found. To go further in the test of the theory, the target is prepared in an oriented state. It is the first time that such collision experiments with oriented target is performed with such a high resolution. The right-left asymmetry expected for the scattering angle distribution is evidenced. The agreement between MOCC calculations and experiments is very good. Simple models developed for collisions with oriented target are also discussed. (author) [fr

  12. Lattice diffusion of a single molecule in solution

    Science.gov (United States)

    Ruggeri, Francesca; Krishnan, Madhavi

    2017-12-01

    The ability to trap a single molecule in an electrostatic potential well in solution has opened up new possibilities for the use of molecular electrical charge to study macromolecular conformation and dynamics at the level of the single entity. Here we study the diffusion of a single macromolecule in a two-dimensional lattice of electrostatic traps in solution. We report the ability to measure both the size and effective electrical charge of a macromolecule by observing single-molecule transport trajectories, typically a few seconds in length, using fluorescence microscopy. While, as shown previously, the time spent by the molecule in a trap is a strong function of its effective charge, we demonstrate here that the average travel time between traps in the landscape yields its hydrodynamic radius. Tailoring the pitch of the lattice thus yields two different experimentally measurable time scales that together uniquely determine both the size and charge of the molecule. Since no information is required on the location of the molecule between consecutive departure and arrival events at lattice sites, the technique is ideally suited to measurements on weakly emitting entities such as single molecules.

  13. New metabolites of hongdenafil, homosildenafil and hydroxyhomosildenafil.

    Science.gov (United States)

    Yeo, Miseon; Park, Yujin; Lee, Heesang; Choe, Sanggil; Baek, Seung-Hoon; Kim, Hye Kyung; Pyo, Jae Sung

    2018-02-05

    Recently, illegal sildenafil analogues have emerged, causing serious social issues. In spite of the importance of sildenafil analogues, their metabolic profiles or clinical effects have not been reported yet. In this study, new metabolites of illegal sildenafil analogues such as hongdenafil, homosildenafil, and hydroxyhomosildenafil were determined using liquid chromatography quadrupole-time of flight mass spectrometry (LC-Q-TOF-MS) and tandem mass spectrometry (LC-Q-TOF-MS/MS). To prepare metabolic samples, in vitro and in vivo studies were performed. For in vivo metabolites analysis, urine and feces samples of rats treated with sildenafil analogues were analyzed. For in vitro metabolites analysis, human liver microsomes incubated with sildenafil analogues were extracted and analyzed. All metabolites were characterized by LC-Q-TOF-MS and LC-Q-TOF-MS/MS. As a result, five, six, and seven metabolites were determined in hongdenafil, homosildenafil, and hydroxyhomosildenafil treated samples, respectively. These results could be applied to forensic science and other analytical fields. Moreover, these newly identified metabolites could be used as fundamental data to determine the side effect and toxicity of illegal sildenafil analogues. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Electronic shell structure in multiply charged silver clusters

    International Nuclear Information System (INIS)

    Kandler, O.; Athanassenas, K.; Echt, O.; Kreisle, D.; Leisner, T.; Recknagel, E.

    1991-01-01

    Silver clusters are generated by standard laser vaporization technique and ionized via multiphoton ionization. Time-of-flight mass spectrometry reveals singly, doubly and triply charged clusters, Ag n z+ (z=1, 2, 3). The spectra show, for all charge states, intensity variations, indicating enhanced stabilities for cluster sizes with closed electronic configurations in accord with the spherical jellium model. (orig.)

  15. Organic field-effect transistors using single crystals

    Directory of Open Access Journals (Sweden)

    Tatsuo Hasegawa and Jun Takeya

    2009-01-01

    Full Text Available Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs, the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20–40 cm2 Vs−1, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps.

  16. METscout: a pathfinder exploring the landscape of metabolites, enzymes and transporters.

    Science.gov (United States)

    Geffers, Lars; Tetzlaff, Benjamin; Cui, Xiao; Yan, Jun; Eichele, Gregor

    2013-01-01

    METscout (http://metscout.mpg.de) brings together metabolism and gene expression landscapes. It is a MySQL relational database linking biochemical pathway information with 3D patterns of gene expression determined by robotic in situ hybridization in the E14.5 mouse embryo. The sites of expression of ∼1500 metabolic enzymes and of ∼350 solute carriers (SLCs) were included and are accessible as single cell resolution images and in the form of semi-quantitative image abstractions. METscout provides several graphical web-interfaces allowing navigation through complex anatomical and metabolic information. Specifically, the database shows where in the organism each of the many metabolic reactions take place and where SLCs transport metabolites. To link enzymatic reactions and transport, the KEGG metabolic reaction network was extended to include metabolite transport. This network in conjunction with spatial expression pattern of the network genes allows for a tracing of metabolic reactions and transport processes across the entire body of the embryo.

  17. ANISOTROPY EFFECTS IN SINGLE-ELECTRON TRANSFER BETWEEN LASER-EXCITED ATOMS AND HIGHLY-CHARGED IONS

    NARCIS (Netherlands)

    Recent collision experiments are reviewed in which one-electron transfer between laser excited target atoms and (highly charged) keV-ions has been studied. Especially results showing a dependence of the charge exchange on the initial target orbital alignment are discussed. The question to what

  18. Charge state of ions scattered by metal surface

    International Nuclear Information System (INIS)

    Kishinevsky, L.M.; Parilis, E.S.; Verleger, V.K.

    1976-01-01

    A model for description of charge distributions for scattering of heavy ions in the keV region, on metal surfaces developing and improving the method of Van der Weg and Bierman, and taking into account the connection between the ion charge state and scattering kinematics, is proposed. It is shown that multiple charged particles come from ions with a vacancy in the inner shell while the outer shell vacancies give only single charged ions and neutrals. The approximately linear increase of degree of ionization with normal velocity, and the non-monotonic charge dependence of the energy spectrum established by Chicherov and Buck et al is explained by considering irreversible neutralization in the depth of the metal, taking into account the connection of the charge state with the shape of trajectory and its location relative to the metal surface. The dependence of charge state on surface structure is discussed. Some new experiments are proposed. (author)

  19. Revisiting conserved charges in higher curvature gravitational theories

    Science.gov (United States)

    Ghodrati, M.; Hajian, K.; Setare, M. R.

    2016-12-01

    Restricting the covariant gravitational phase spaces to the manifold of parametrized families of solutions, the mass, angular momenta, entropies, and electric charges can be calculated by a single and simple method. In this method, which has been called the "solution phase space method," conserved charges are unambiguous and regular. Moreover, assuming the generators of the charges to be exact symmetries, entropies and other conserved charges can be calculated on almost arbitrary surfaces, not necessarily horizons or asymptotics. Hence, the first law of thermodynamics would be a local identity relating the exact symmetries to which the mass, angular momentum, electric charge, and entropy are attributed. In this paper, we apply this powerful method to the f( R) gravitational theories accompanied by the terms quadratic in the Riemann and Ricci tensors. Furthermore, conserved charges and the first law of thermodynamics for some of their black hole solutions are exemplified. The examples include warped AdS_3, charged static BTZ, and 3-dimensional z=3 Lifshitz black holes.

  20. Familial Resemblance for Serum Metabolite Concentrations

    NARCIS (Netherlands)

    Draisma, H.H.M.; Beekman, M.; Pool, R.; van Ommen, G.J.B; Vaarhorst, A.A.M.; de Craen, A.J.; Willemsen, G.; Slagboom, P.E.; Boomsma, D.I.

    2013-01-01

    Metabolomics is the comprehensive study of metabolites, which are the substrates, intermediate, and end products of cellular metabolism. The heritability of the concentrations of circulating metabolites bears relevance for evaluating their suitability as biomarkers for disease. We report aspects of

  1. Metabolite Depletion Affects Flux Profiling of Cell Lines

    DEFF Research Database (Denmark)

    Nilsson, A.; Haanstra, J. R.; Teusink, B.

    2018-01-01

    Quantifying the rate of consumption and release of metabolites (i.e., flux profiling) has become integral to the study of cancer. The fluxes as well as the growth of the cells may be affected by metabolite depletion during cultivation.......Quantifying the rate of consumption and release of metabolites (i.e., flux profiling) has become integral to the study of cancer. The fluxes as well as the growth of the cells may be affected by metabolite depletion during cultivation....

  2. Pion-nucleus double charge exchange and the nuclear shell model

    International Nuclear Information System (INIS)

    Auerbach, N.; Gibbs, W.R.; Ginocchio, J.N.; Kaufmann, W.B.

    1988-01-01

    The pion-nucleus double charge exchange reaction is studied with special emphasis on nuclear structure. The reaction mechanism and nuclear structure aspects of the process are separated using both the plane-wave and distorted-wave impulse approximations. Predictions are made employing both the seniority model and a full shell model (with a single active orbit). Transitions to the double analog state and to the ground state of the residual nucleus are computed. The seniority model yields particularly simple relations among double charge exchange cross sections for nuclei within the same shell. Limitations of the seniority model and of the plane-wave impulse approximation are discussed as well as extensions to the generalized seniority scheme. Applications of the foregoing ideas to single charge exchange are also presented

  3. An induced charge readout scheme incorporating image charge splitting on discrete pixels

    International Nuclear Information System (INIS)

    Kataria, D.O.; Lapington, J.S.

    2003-01-01

    Top hat electrostatic analysers used in space plasma instruments typically use microchannel plates (MCPs) followed by discrete pixel anode readout for the angular definition of the incoming particles. Better angular definition requires more pixels/readout electronics channels but with stringent mass and power budgets common in space applications, the number of channels is restricted. We describe here a technique that improves the angular definition using induced charge and an interleaved anode pattern. The technique adopts the readout philosophy used on the CRRES and CLUSTER I instruments but has the advantages of the induced charge scheme and significantly reduced capacitance. Charge from the MCP collected by an anode pixel is inductively split onto discrete pixels whose geometry can be tailored to suit the scientific requirements of the instrument. For our application, the charge is induced over two pixels. One of them is used for a coarse angular definition but is read out by a single channel of electronics, allowing a higher rate handling. The other provides a finer angular definition but is interleaved and hence carries the expense of lower rate handling. Using the technique and adding four channels of electronics, a four-fold increase in the angular resolution is obtained. Details of the scheme and performance results are presented

  4. Acoustic effects of single electrostatic discharges

    International Nuclear Information System (INIS)

    Orzech, Łukasz

    2015-01-01

    Electric discharges, depending on their character, can emit different types of energy, resulting in different effects. Single electrostatic discharges besides generation of electromagnetic pulses are also the source of N acoustic waves. Their specified parameters depending on amount of discharging charge enable determination of value of released charge in a function of acoustic descriptor (e.g. acoustic pressure). Presented approach is the basics of acoustic method for measurement of single electrostatic discharges, enabling direct and contactless measurement of value of charge released during ESD. Method for measurement of acoustic effect of impact of a single electrostatic discharge on the environment in a form of pressure shock wave and examples of acoustic descriptors in a form of equation Q=f(p a ) are described. The properties of measuring system as well as the results of regression static analyses used to determine the described relationships are analysed in details. (paper)

  5. Simvastatin (SV) metabolites in mouse tissues

    International Nuclear Information System (INIS)

    Duncan, C.A.; Vickers, S.

    1990-01-01

    SV, a semisynthetic analog of lovastatin, is hydrolyzed in vivo to its hydroxy acid (SVA), a potent inhibitor of HMG CoA reductase (HR). Thus SV lowers plasma cholesterol. SV is a substrate for mixed function oxidases whereas SVA undergoes lactonization and β-oxidation. Male CD-1 mice were dosed orally with a combination of ( 14 C)SV and ( 3 H)SVA at 25 mg/kg of each, bled and killed at 0.5, 2 and 4 hours. Labeled SV, SVA, 6'exomethylene SV (I), 6'CH 2 OH-SV (II), 6'COOH-SV (III) and a β-oxidized metabolite (IV) were assayed in liver, bile, kidneys, testes and plasma by RIDA. Levels of potential and active HR inhibitors in liver were 10 to 40 fold higher than in other tissues. II and III, in which the configuration at 6' is inverted, may be 2 metabolites of I. Metabolites I-III are inhibitors of HR in their hydroxy acid forms. Qualitatively ( 14 C)SV and ( 3 H)SVA were metabolized similarly (consistent with their proposed interconversion). However 3 H-SVA, I-III (including hydroxy acid forms) achieved higher concentrations than corresponding 14 C compounds (except in gall bladder bile). Major radioactive metabolites in liver were II-IV (including hydroxy acid forms). These metabolites have also been reported in rat tissues. In bile a large fraction of either label was unidentified polar metabolites. The presence of IV indicated that mice (like rats) are not good models for SV metabolism in man

  6. Drug repositioning for enzyme modulator based on human metabolite-likeness.

    Science.gov (United States)

    Lee, Yoon Hyeok; Choi, Hojae; Park, Seongyong; Lee, Boah; Yi, Gwan-Su

    2017-05-31

    Recently, the metabolite-likeness of the drug space has emerged and has opened a new possibility for exploring human metabolite-like candidates in drug discovery. However, the applicability of metabolite-likeness in drug discovery has been largely unexplored. Moreover, there are no reports on its applications for the repositioning of drugs to possible enzyme modulators, although enzyme-drug relations could be directly inferred from the similarity relationships between enzyme's metabolites and drugs. We constructed a drug-metabolite structural similarity matrix, which contains 1,861 FDA-approved drugs and 1,110 human intermediary metabolites scored with the Tanimoto similarity. To verify the metabolite-likeness measure for drug repositioning, we analyzed 17 known antimetabolite drugs that resemble the innate metabolites of their eleven target enzymes as the gold standard positives. Highly scored drugs were selected as possible modulators of enzymes for their corresponding metabolites. Then, we assessed the performance of metabolite-likeness with a receiver operating characteristic analysis and compared it with other drug-target prediction methods. We set the similarity threshold for drug repositioning candidates of new enzyme modulators based on maximization of the Youden's index. We also carried out literature surveys for supporting the drug repositioning results based on the metabolite-likeness. In this paper, we applied metabolite-likeness to repurpose FDA-approved drugs to disease-associated enzyme modulators that resemble human innate metabolites. All antimetabolite drugs were mapped with their known 11 target enzymes with statistically significant similarity values to the corresponding metabolites. The comparison with other drug-target prediction methods showed the higher performance of metabolite-likeness for predicting enzyme modulators. After that, the drugs scored higher than similarity score of 0.654 were selected as possible modulators of enzymes for

  7. Optical properties of two-dimensional charge density wave materials

    Science.gov (United States)

    Sayers, Charles; Karbassi, Sara; Friedemann, Sven; da Como, Enrico

    Titanium diselenide (TiSe2) is a member of the layered transition metal dichalcogenide (TMD) materials. It exhibits unusual chiral charge ordering below 190 K after undergoing an initial phase transition to a commensurate (2 x 2 x 2) charge density wave (CDW) at 200 K which is enhanced further in the monolayer. Recently, the first evidence of chirality in a CDW system was discovered in this material by scanning tunneling microscopy and time-resolved reflectivity experiments, where separate left and right handed charge-ordered domains were found to exist within a single sample. We have prepared single crystals of 1T-TiSe2 using iodine vapour transport, and confirmed their quality by x-ray analysis and charge transport measurements. Using a combination of polarised optical spectroscopy techniques in the mid to far infrared (4 to 700 meV photon energy), we have measured an anisotropy relating to the CDW gap. We discuss the results on the basis of chiral domains with different handedness and the nature of the CDW transition.

  8. Metabolites of cannabidiol identified in human urine.

    Science.gov (United States)

    Harvey, D J; Mechoulam, R

    1990-03-01

    1. Urine from a dystonic patient treated with cannabidiol (CBD) was examined by g.l.c.-mass spectrometry for CBD metabolites. Metabolites were identified as their trimethylsilyl (TMS), [2H9]TMS, and methyl ester/TMS derivatives and as the TMS derivatives of the product of lithium aluminium deuteride reduction. 2. Thirty-three metabolites were identified in addition to unmetabolized CBD, and a further four metabolites were partially characterized. 3. The major metabolic route was hydroxylation and oxidation at C-7 followed by further hydroxylation in the pentyl and propenyl groups to give 1"-, 2"-, 3"-, 4"- and 10-hydroxy derivatives of CBD-7-oic acid. Other metabolites, mainly acids, were formed by beta-oxidation and related biotransformations from the pentyl side-chain and these were also hydroxylated at C-6 or C-7. The major oxidized metabolite was CBD-7-oic acid containing a hydroxyethyl side-chain. 4. Two 8,9-dihydroxy compounds, presumably derived from the corresponding epoxide were identified. 5. Also present were several cyclized cannabinoids including delta-6- and delta-1-tetrahydrocannabinol and cannabinol. 6. This is the first metabolic study of CBD in humans; most observed metabolic routes were typical of those found for CBD and related cannabinoids in other species.

  9. Charge Transport Processes in Molecular Junctions

    Science.gov (United States)

    Smith, Christopher Eugene

    Molecular electronics (ME) has evolved into a rich area of exploration that combines the fields of chemistry, materials, electronic engineering and computational modeling to explore the physics behind electronic conduction at the molecular level. Through studying charge transport properties of single molecules and nanoscale molecular materials the field has gained the potential to bring about new avenues for the miniaturization of electrical components where quantum phenomena are utilized to achieve solid state molecular device functionality. Molecular junctions are platforms that enable these studies and consist of a single molecule or a small group of molecules directly connected to electrodes. The work presented in this thesis has built upon the current understanding of the mechanisms of charge transport in ordered junctions using self-assembled monolayer (SAM) molecular thin films. Donor and acceptor compounds were synthesized and incorporated into SAMs grown on metal substrates then the transport properties were measured with conducting probe atomic force microscopy (CP-AFM). In addition to experimentally measured current-voltage (I-V) curves, the transport properties were addressed computationally and modeled theoretically. The key objectives of this project were to 1) investigate the impact of molecular structure on hole and electron charge transport, 2) understand the nature of the charge carriers and their structure-transport properties through long (chemically gated to modulate the transport. These results help advance our understanding of transport behavior in semiconducting molecular thin films, and open opportunities to engineer improved electronic functionality into molecular devices.

  10. Morphine metabolites

    DEFF Research Database (Denmark)

    Christrup, Lona Louring

    1997-01-01

    , morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) are the major metabolites of morphine. The metabolism of morphine occurs not only in the liver, but may also take place in the brain and the kidneys. The glucuronides are mainly eliminated via bile and urine. Glucuronides as a rule...... are considered as highly polar metabolites unable to cross the blood-brain barrier. Although morphine glucuronidation has been demonstrated in human brain tissue, the capacity is very low compared to that of the liver, indicating that the M3G and M6G concentrations observed in the cerebrospinal fluid (CSF) after...... systemic administration reflect hepatic metabolism of morphine and that the morphine glucuronides, despite their high polarity, can penetrate into the brain. Like morphine, M6G has been shown to be relatively more selective for mu-receptors than for delta- and kappa-receptors while M3G does not appear...

  11. [Effect of different fertilization treatments on yield and secondary metabolites of Codonopsis pilosula].

    Science.gov (United States)

    Hu, Jia-Dong; Mao, Ge; Zhang, Zhi-Wei; Ma, Cun-de; Liang, Zong-Suo; Xia, Guang-Dong; Dong, Juan-E

    2017-08-01

    The research studies the effect of different fertilization treatments on yield and accumulation of secondary metabolites of Codonopsis pilosula by using single factor randomized block design, in order to ensure reasonable harvesting time and fertilization ratio, and provide the basis for standardized cultivation of C. pilosula. According to the clustering results, the nitrogen fertilizer benefitted for the improvement of root diameter and biomass of C. pilosula. The phosphate fertilizer could promote the content of C. pilosula polysaccharide. The organic fertilizers could increase the content of lobetyolin. With the time going on, C. pilosula's yield, polysaccharide and ehanol-soluble extracts increased while the content of lobetyolin decreased. According to various factors, October is a more reasonable harvest period. Organic fertilizers are more helpful to the yield and accumulation of secondary metabolites of C. pilosula. Copyright© by the Chinese Pharmaceutical Association.

  12. Interactions between amphibians’ symbiotic bacteria cause the production of emergent anti-fungal metabolites

    Directory of Open Access Journals (Sweden)

    Andrew Howard Loudon

    2014-08-01

    Full Text Available Amphibians possess beneficial skin bacteria that protect against the disease chytridiomycosis by producing secondary metabolites that inhibit the pathogen Batrachochytrium dendrobatidis (Bd. Metabolite production may be a mechanism of competition between bacterial species that results in host protection as a by-product. We expect that some co-cultures of bacterial species or strains will result in greater Bd inhibition than mono-cultures. To test this, we cultured four bacterial isolates (Bacillus sp., Janthinobacterium sp., Pseudomonas sp. and Chitinophaga arvensicola from red-backed salamanders (Plethodon cinereus and cultured isolates both alone and together to collect their cell-free supernatants (CFS. We challenged Bd with CFSs from four bacterial species in varying combinations. This resulted in three experimental treatments: 1 CFSs of single isolates; 2 combined CFSs of two isolates; and 3 CFSs from co-cultures. Pair-wise combinations of four bacterial isolates CFSs were assayed against Bd and revealed additive Bd inhibition in 42.2% of trials, synergistic inhibition in 42.2% and no effect in 16.6% of trials. When bacteria isolates were grown in co-cultures, complete Bd inhibition was generally observed, and synergistic inhibition occurred in four out of six trials. A metabolite profile of the most potent co-culture, Bacillus sp. and Chitinophaga arvensicola, was determined with LC-MS and compared with the profiles of each isolate in mono-culture. Emergent metabolites appearing in the co-culture were inhibitory to Bd, and the most potent inhibitor was identified as tryptophol. Thus mono-cultures of bacteria cultured from red-backed salamanders interacted synergistically and additively to inhibit Bd, and such bacteria produced emergent metabolites when cultured together, with even greater pathogen inhibition. Knowledge of how bacterial species interact to inhibit Bd can be used to select probiotics to provide amphibians with protection

  13. Stratified charge rotary aircraft engine technology enablement program

    Science.gov (United States)

    Badgley, P. R.; Irion, C. E.; Myers, D. M.

    1985-01-01

    The multifuel stratified charge rotary engine is discussed. A single rotor, 0.7L/40 cu in displacement, research rig engine was tested. The research rig engine was designed for operation at high speeds and pressures, combustion chamber peak pressure providing margin for speed and load excursions above the design requirement for a high is advanced aircraft engine. It is indicated that the single rotor research rig engine is capable of meeting the established design requirements of 120 kW, 8,000 RPM, 1,379 KPA BMEP. The research rig engine, when fully developed, will be a valuable tool for investigating, advanced and highly advanced technology components, and provide an understanding of the stratified charge rotary engine combustion process.

  14. KEKCB electron cyclotron resonance charge breeder at TRIAC

    International Nuclear Information System (INIS)

    Imai, N.; Jeong, S. C.; Oyaizu, M.; Arai, S.; Fuchi, Y.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Tanaka, M. H.; Okada, M.; Watanabe, Y. X.; Ichikawa, S.; Kabumoto, H.; Osa, A.; Otokawa, Y.; Sato, T. K.

    2008-01-01

    The KEKCB is an electron cyclotron resonance (ECR) ion source for converting singly charged ions to multicharged ones at Tokai Radioactive Ion Accelerator Complex. By using the KEKCB, singly charged gaseous and nongaseous ions were converted to multicharged ones of A/q≅7 with efficiencies of 7% and 2%, respectively. The conversion efficiency was found to be independent of the lifetime of the radioactive nuclei having lifetimes of the order of one second. Three collimators located at the entrance and the exit of the KEKCB defined the beam axis and facilitated beam injection. Grinding and washing the surfaces of aluminum electrode and plasma chamber dramatically reduced impurities originating from the ECR plasma of the KEKCB

  15. Fast mapping of the T2 relaxation time of cerebral metabolites using proton echo-planar spectroscopic imaging (PEPSI).

    Science.gov (United States)

    Tsai, Shang-Yueh; Posse, Stefan; Lin, Yi-Ru; Ko, Cheng-Wen; Otazo, Ricardo; Chung, Hsiao-Wen; Lin, Fa-Hsuan

    2007-05-01

    Metabolite T2 is necessary for accurate quantification of the absolute concentration of metabolites using long-echo-time (TE) acquisition schemes. However, lengthy data acquisition times pose a major challenge to mapping metabolite T2. In this study we used proton echo-planar spectroscopic imaging (PEPSI) at 3T to obtain fast T2 maps of three major cerebral metabolites: N-acetyl-aspartate (NAA), creatine (Cre), and choline (Cho). We showed that PEPSI spectra matched T2 values obtained using single-voxel spectroscopy (SVS). Data acquisition for 2D metabolite maps with a voxel volume of 0.95 ml (32 x 32 image matrix) can be completed in 25 min using five TEs and eight averages. A sufficient spectral signal-to-noise ratio (SNR) for T2 estimation was validated by high Pearson's correlation coefficients between logarithmic MR signals and TEs (R2 = 0.98, 0.97, and 0.95 for NAA, Cre, and Cho, respectively). In agreement with previous studies, we found that the T2 values of NAA, but not Cre and Cho, were significantly different between gray matter (GM) and white matter (WM; P PEPSI and SVS scans was less than 9%. Consistent spatial distributions of T2 were found in six healthy subjects, and disagreement among subjects was less than 10%. In summary, the PEPSI technique is a robust method to obtain fast mapping of metabolite T2. (c) 2007 Wiley-Liss, Inc.

  16. Argon-ion charge distributions following near-threshold ionization

    International Nuclear Information System (INIS)

    Levin, J.C.

    1990-01-01

    When an atom is photoionized in an inner shell, there are two mechanisms by which the remaining electron cortege relaxes to fill the vacancy: x-ray emission and radiationless Auger and Coster-Kronig transitions. In the former, the inner-shell hole moves to a less tightly bound orbital without increasing the number of atomic vacancies. In Auger processes, however, the energy liberated by transfer of a less-tightly-bound electron to the inner-shell vacancy is transferred to another electron which is ejected into the continuum. In this case, the charge on the residual ion increases by one. Through a series of radiative and non-radiative processes, the initial vacancy bubbles up until all vacancies arrive at the outermost shell. Due to the many possible routes by which this may occur, there can be a broad distribution of residual ion charge states characteristic of the decay of a single inner-shell vacancy. Because so many processes can contribute to each charge state, it is difficult to determine the effect of each by examining the total ion charge distribution; the total-ion charge distribution represents an average over many effects. To overcome this limitation, the author has recently measured argon-ion production as a function of both photon energy and Auger decay channel following photoionization of K-shell electrons with highly monochromatic synchrotron radiation. When measured differential in decay channel, the ion charge distributions are greatly simplified. Analysis, in progress, of these simplified distributions will permit extraction of information about relative decay rates and shakeoff effects that is obscured in the single spectra

  17. Manipulating quantum coherence of charge states in interacting double-dot Aharonov–Bohm interferometers

    Science.gov (United States)

    Jin, Jinshuang; Wang, Shikuan; Zhou, Jiahuan; Zhang, Wei-Min; Yan, YiJing

    2018-04-01

    We investigate the dynamics of charge-state coherence in a degenerate double-dot Aharonov–Bohm interferometer with finite inter-dot Coulomb interactions. The quantum coherence of the charge states is found to be sensitive to the transport setup configurations, involving both the single-electron impurity channels and the Coulomb-assisted ones. We numerically demonstrate the emergence of a complete coherence between the two charge states, with the relative phase being continuously controllable through the magnetic flux. Interestingly, a fully coherent charge qubit arises at the double-dots electron pair tunneling resonance condition, where the chemical potential of one electrode is tuned at the center between a single-electron impurity channel and the related Coulomb-assisted channel. This pure quantum state of charge qubit could be experimentally realized at the current–voltage characteristic turnover position, where differential conductance sign changes. We further elaborate the underlying mechanism for both the real-time and the stationary charge-states coherence in the double-dot systems of study.

  18. Topology of charge density of flucytosine and related molecules and characteristics of their bond charge distributions.

    Science.gov (United States)

    Murgich, Juan; Franco, Héctor J; San-Blas, Gioconda

    2006-08-24

    The molecular charge distribution of flucytosine (4-amino-5-fluoro-2-pyrimidone), uracil, 5-fluorouracil, and thymine was studied by means of density functional theory calculations (DFT). The resulting distributions were analyzed by means of the atoms in molecules (AIM) theory. Bonds were characterized through vectors formed with the charge density value, its Laplacian, and the bond ellipticity calculated at the bond critical point (BCP). Within each set of C=O, C-H, and N-H bonds, these vectors showed little dispersion. C-C bonds formed three different subsets, one with a significant degree of double bonding, a second corresponding to single bonds with a finite ellipticity produced by hyperconjugation, and a third one formed by a pure single bond. In N-C bonds, a decrease in bond length (an increase in double bond character) was not reflected as an increase in their ellipticity, as in all C-C bonds studied. It was also found that substitution influenced the N-C, C-O, and C-C bond ellipticity much more than density and its Laplacian at the BCP. The Laplacian of charge density pointed to the existence of both bonding and nonbonding maxima in the valence shell charge concentration of N, O, and F, while only bonding ones were found for the C atoms. The nonbonding maxima related to the sites for electrophilic attack and H bonding in O and N, while sites of nucleophilic attack were suggested by the holes in the valence shell of the C atoms of the carbonyl groups.

  19. (1) H-MRS processing parameters affect metabolite quantification

    DEFF Research Database (Denmark)

    Bhogal, Alex A; Schür, Remmelt R; Houtepen, Lotte C

    2017-01-01

    investigated the influence of model parameters and spectral quantification software on fitted metabolite concentration values. Sixty spectra in 30 individuals (repeated measures) were acquired using a 7-T MRI scanner. Data were processed by four independent research groups with the freedom to choose their own...... + NAAG/Cr + PCr and Glu/Cr + PCr, respectively. Metabolite quantification using identical (1) H-MRS data was influenced by processing parameters, basis sets and software choice. Locally preferred processing choices affected metabolite quantification, even when using identical software. Our results......Proton magnetic resonance spectroscopy ((1) H-MRS) can be used to quantify in vivo metabolite levels, such as lactate, γ-aminobutyric acid (GABA) and glutamate (Glu). However, there are considerable analysis choices which can alter the accuracy or precision of (1) H-MRS metabolite quantification...

  20. Charge-density study of crystalline beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R F [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry

    1977-01-01

    The X-ray structure factors for crystalline beryllium measured by Brown (Phil. Mag. (1972), 26, 1377) have been analyzed with multipole deformation functions for charge-density information. Single exponential radial functions were used for the valence charge density. A valence monopole plus the three harmonics, P/sup 3//sub 5/(cos theta) sin 3phi, P/sub 6/(cos theta) and P/sup 3//sub 7/(cos theta) sin 3phi, provide a least-squares fit to the data with Rsub(w)=0.0081. The superposition of these density functions describes a bonding charge density between Be atoms along the c axis through the tetrahedral vacancy. The results reported here are in qualitative agreement with a recent pseudo-potential calculation of metallic beryllium. The final residuals in the analysis are largest at high sin theta/lambda values. This suggests that core charge deformation is present and/or anharmonic motion of the nuclei is appreciable.

  1. Ab initio investigation of sulfur monofluoride and its singly charged cation and anion in their ground electronic state

    International Nuclear Information System (INIS)

    Li Song; Chen Shan-Jun; Chen Yan; Chen Peng

    2016-01-01

    The SF radical and its singly charged cation and anion, SF + and SF − , have been investigated on the MRCI/aug-cc-pVXZ (X = Q, 5, 6) levels of theory with Davidson correction. Both the core–valence correlation and the relativistic effect are considered. The extrapolating to the complete basis set (CBS) limit is adopted to remove the basis set truncation error. Geometrical parameters, potential energy curves (PECs), vibrational energy levels, spectroscopic constants, ionization potentials, and electron affinities of the ground electronic state for all these species are obtained. The information with respect to molecular characteristics of the SF n (n = −1, 0, +1) systems derived in this work will help to extend our knowledge and to guide further experimental or theoretical researches. (paper)

  2. Fragmentation of organic ions bearing fixed multiple charges observed in MALDI MS.

    Science.gov (United States)

    Lou, Xianwen; Li, Bao; de Waal, Bas F M; Schill, Jurgen; Baker, Matthew B; Bovee, Ralf A A; van Dongen, Joost L J; Milroy, Lech-Gustav; Meijer, E W

    2018-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) was used to analyze a series of synthetic organic ions bearing fixed multiple charges. Despite the multiple intrinsic charges, only singly charged ions were recorded in each case. In addition to the pseudo-molecular ions formed by counterion adduction, deprotonation and electron capture, a number of fragment ions were also observed. Charge splitting by fragmentation was found to be a viable route for charge reduction leading to the formation of the observed singly charged fragment ions. Unlike multivalent metal ions, organic ions can rearrange and/or fragment during charge reduction. This fragmentation process will evidently complicate the interpretation of the MALDI MS spectrum. Because MALDI MS is usually considered as a soft ionization technique, the fragment ion peaks can easily be erroneously interpreted as impurities. Therefore, the awareness and understanding of the underlying MALDI-induced fragmentation pathways is essential for a proper interpretation of the corresponding mass spectra. Due to the fragment ions generated during charge reduction, special care should be taken in the MALDI MS analysis of multiply charged ions. In this work, the possible mechanisms by which the organic ions bearing fixed multiple charges fragment are investigated. With an improved understanding of the fragmentation mechanisms, MALDI TOF MS should still be a useful technique for the characterization of organic ions with fixed multiple charges. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Langevin dynamics of conformational transformations induced by the charge-curvature interaction

    DEFF Research Database (Denmark)

    Gaididei, Yuri Borisovich; Gorria, C.; Christiansen, Peter Leth

    2009-01-01

    The role of thermal fluctuations in the conformational dynamics of a single closed filament is studied. It is shown that, due to the interaction between charges and bending degrees of freedom, initially circular chains may undergo transformation to polygonal shape.......The role of thermal fluctuations in the conformational dynamics of a single closed filament is studied. It is shown that, due to the interaction between charges and bending degrees of freedom, initially circular chains may undergo transformation to polygonal shape....

  4. Electrochemically-gated single-molecule electrical devices

    International Nuclear Information System (INIS)

    Guo, Shaoyin; Artés, Juan Manuel; Díez-Pérez, Ismael

    2013-01-01

    In the last decade, single-molecule electrical contacts have emerged as a new experimental platform that allows exploring charge transport phenomena in individual molecular blocks. This novel tool has evolved into an essential element within the Molecular Electronics field to understand charge transport processes in hybrid (bio)molecule/electrode interfaces at the nanoscale, and prospect the implementation of active molecular components into functional nanoscale optoelectronic devices. Within this area, three-terminal single-molecule devices have been sought, provided that they are highly desired to achieve full functionality in logic electronic circuits. Despite the latest experimental developments offer consistent methods to bridge a molecule between two electrodes (source and drain in a transistor notation), placing a third electrode (gate) close to the single-molecule electrical contact is still technically challenging. In this vein, electrochemically-gated single-molecule devices have emerged as an experimentally affordable alternative to overcome these technical limitations. In this review, the operating principle of an electrochemically-gated single-molecule device is presented together with the latest experimental methodologies to built them and characterize their charge transport characteristics. Then, an up-to-date comprehensive overview of the most prominent examples will be given, emphasizing on the relationship between the molecular structure and the final device electrical behaviour

  5. Revisiting conserved charges in higher curvature gravitational theories

    Energy Technology Data Exchange (ETDEWEB)

    Ghodrati, M. [University of Michigan, Michigan Center for Theoretical Physics, Randall Laboratory of Physics, Ann Arbor, MI (United States); Hajian, K. [Institute for Research in Fundamental Sciences (IPM), School of Physics, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Setare, M.R. [University of Kurdistan, Department of Science, Campus of Bijar, Bijar (Iran, Islamic Republic of)

    2016-12-15

    Restricting the covariant gravitational phase spaces to the manifold of parametrized families of solutions, the mass, angular momenta, entropies, and electric charges can be calculated by a single and simple method. In this method, which has been called the ''solution phase space method,'' conserved charges are unambiguous and regular. Moreover, assuming the generators of the charges to be exact symmetries, entropies and other conserved charges can be calculated on almost arbitrary surfaces, not necessarily horizons or asymptotics. Hence, the first law of thermodynamics would be a local identity relating the exact symmetries to which the mass, angular momentum, electric charge, and entropy are attributed. In this paper, we apply this powerful method to the f(R) gravitational theories accompanied by the terms quadratic in the Riemann and Ricci tensors. Furthermore, conserved charges and the first law of thermodynamics for some of their black hole solutions are exemplified. The examples include warped AdS{sub 3}, charged static BTZ, and 3-dimensional z = 3 Lifshitz black holes. (orig.)

  6. Revisiting conserved charges in higher curvature gravitational theories

    International Nuclear Information System (INIS)

    Ghodrati, M.; Hajian, K.; Setare, M.R.

    2016-01-01

    Restricting the covariant gravitational phase spaces to the manifold of parametrized families of solutions, the mass, angular momenta, entropies, and electric charges can be calculated by a single and simple method. In this method, which has been called the ''solution phase space method,'' conserved charges are unambiguous and regular. Moreover, assuming the generators of the charges to be exact symmetries, entropies and other conserved charges can be calculated on almost arbitrary surfaces, not necessarily horizons or asymptotics. Hence, the first law of thermodynamics would be a local identity relating the exact symmetries to which the mass, angular momentum, electric charge, and entropy are attributed. In this paper, we apply this powerful method to the f(R) gravitational theories accompanied by the terms quadratic in the Riemann and Ricci tensors. Furthermore, conserved charges and the first law of thermodynamics for some of their black hole solutions are exemplified. The examples include warped AdS 3 , charged static BTZ, and 3-dimensional z = 3 Lifshitz black holes. (orig.)

  7. Study of CP-violating charge asymmetries of single muons and like-sign dimuons in p pbar collisions

    Czech Academy of Sciences Publication Activity Database

    Abazov, V. M.; Abbott, B.; Acharya, B.S.; Kupčo, Alexander; Lokajíček, Miloš

    2014-01-01

    Roč. 89, č. 1 (2014), "012002-1"-"012002-31" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG12006 Institutional support: RVO:68378271 Keywords : D0 * Fermilab * charge asymmetry * CP violation * same sign * charge: asymmetry * dimuon * charge * muon * charge * meson * mixing * width difference Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  8. A Decade in the MIST: Learnings from Investigations of Drug Metabolites in Drug Development under the "Metabolites in Safety Testing" Regulatory Guidance.

    Science.gov (United States)

    Schadt, Simone; Bister, Bojan; Chowdhury, Swapan K; Funk, Christoph; Hop, Cornelis E C A; Humphreys, W Griffith; Igarashi, Fumihiko; James, Alexander D; Kagan, Mark; Khojasteh, S Cyrus; Nedderman, Angus N R; Prakash, Chandra; Runge, Frank; Scheible, Holger; Spracklin, Douglas K; Swart, Piet; Tse, Susanna; Yuan, Josh; Obach, R Scott

    2018-06-01

    Since the introduction of metabolites in safety testing (MIST) guidance by the Food and Drug Administration in 2008, major changes have occurred in the experimental methods for the identification and quantification of metabolites, ways to evaluate coverage of metabolites, and the timing of critical clinical and nonclinical studies to generate this information. In this cross-industry review, we discuss how the increased focus on human drug metabolites and their potential contribution to safety and drug-drug interactions has influenced the approaches taken by industry for the identification and quantitation of human drug metabolites. Before the MIST guidance was issued, the method of choice for generating comprehensive metabolite profile was radio chromatography. The MIST guidance increased the focus on human drug metabolites and their potential contribution to safety and drug-drug interactions and led to changes in the practices of drug metabolism scientists. In addition, the guidance suggested that human metabolism studies should also be accelerated, which has led to more frequent determination of human metabolite profiles from multiple ascending-dose clinical studies. Generating a comprehensive and quantitative profile of human metabolites has become a more urgent task. Together with technological advances, these events have led to a general shift of focus toward earlier human metabolism studies using high-resolution mass spectrometry and to a reduction in animal radiolabel absorption/distribution/metabolism/excretion studies. The changes induced by the MIST guidance are highlighted by six case studies included herein, reflecting different stages of implementation of the MIST guidance within the pharmaceutical industry. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  9. Enabling fast charging – Vehicle considerations

    Energy Technology Data Exchange (ETDEWEB)

    Meintz, Andrew; Zhang, Jiucai; Vijayagopal, Ram; Kreutzer, Cory; Ahmed, Shabbir; Bloom, Ira; Burnham, Andrew; Carlson, Richard B.; Dias, Fernando; Dufek, Eric J.; Francfort, James; Hardy, Keith; Jansen, Andrew N.; Keyser, Matthew; Markel, Anthony; Michelbacher, Christopher; Mohanpurkar, Manish; Pesaran, Ahmad; Scoffield, Don; Shirk, Matthew; Stephens, Thomas; Tanim, Tanvir

    2017-11-01

    To achieve a successful increase in the plug-in battery electric vehicle (BEV) market, it is anticipated that a significant improvement in battery performance is required to improve the range that BEVs can travel and the rate at which they can be recharged. While the range that BEVs can travel on a single recharge is improving, the recharging rate is still much slower than the refueling rate of conventional internal combustion engine vehicles. To achieve comparable recharge times, we explore the vehicle considerations of charge rates of at least 400 kW. Faster recharge is expected to significantly mitigate the perceived deficiencies for long-distance transportation, to provide alternative charging in densely populated areas where overnight charging at home may not be possible, and to reduce range anxiety for travel within a city when unplanned charging may be required. This substantial increase in charging rate is expected to create technical issues in the design of the battery system and vehicle’s electrical architecture that must be resolved. This work focuses on battery system thermal design and total recharge time to meet the goals of implementing higher charge rates and the impacts of the expected increase in system voltage on the components of the vehicle.

  10. GPCR-Mediated Signaling of Metabolites

    DEFF Research Database (Denmark)

    Husted, Anna Sofie; Trauelsen, Mette; Rudenko, Olga

    2017-01-01

    microbiota target primarily enteroendocrine, neuronal, and immune cells in the lamina propria of the gut mucosa and the liver and, through these tissues, the rest of the body. In contrast, metabolites from the intermediary metabolism act mainly as metabolic stress-induced autocrine and paracrine signals...... and obesity. The concept of key metabolites as ligands for specific GPCRs has broadened our understanding of metabolic signaling significantly and provides a number of novel potential drug targets....

  11. Single particle detecting telescope system

    International Nuclear Information System (INIS)

    Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

    1981-01-01

    We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

  12. Profiling contents of water-soluble metabolites and mineral nutrients to evaluate the effects of pesticides and organic and chemical fertilizers on tomato fruit quality.

    Science.gov (United States)

    Watanabe, Masami; Ohta, Yuko; Licang, Sun; Motoyama, Naoki; Kikuchi, Jun

    2015-02-15

    In this study, the contents of water-soluble metabolites and mineral nutrients were measured in tomatoes cultured using organic and chemical fertilizers, with or without pesticides. Mineral nutrients and water-soluble metabolites were determined by inductively coupled plasma-atomic emission spectrometry and (1)H nuclear magnetic resonance spectrometry, respectively, and results were analysed by principal components analysis (PCA). The mineral nutrient and water-soluble metabolite profiles differed between organic and chemical fertilizer applications, which accounted for 88.0% and 55.4%, respectively, of the variation. (1)H-(13)C-hetero-nuclear single quantum coherence experiments identified aliphatic protons that contributed to the discrimination of PCA. Pesticide application had little effect on mineral nutrient content (except Fe and P), but affected the correlation between mineral nutrients and metabolites. Differences in the content of mineral nutrients and water-soluble metabolites resulting from different fertilizer and pesticide applications probably affect tomato quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Charge-collection efficiency of GaAs field effect transistors fabricated with a low temperature grown buffer layer: dependence on charge deposition profile

    International Nuclear Information System (INIS)

    McMorrow, D.; Knudson, A.R.; Melinger, J.S.; Buchner, S.

    1999-01-01

    The results presented here reveal a surprising dependence of the charge-collection efficiency of LT GaAs FETs (field effect transistors) on the depth profile of the deposited charge. Investigation of the temporal dependence of the signal amplitude, carrier density contours, and potential contours reveals different mechanisms for charge collection arising from carriers deposited above and below the LT GaAs buffer layer, respectively. In particular, carriers deposited below the LT GaAs buffer layer dissipate slowly and give rise to a persistent charge collection that is associated with a bipolar-like gain process. These results may be of significance in understanding the occurrence of single-event upsets from protons, neutrons, and large-angle, glancing heavy-ion strikes. (authors)

  14. Dual Fragment Impact of PBX Charges

    Science.gov (United States)

    Haskins, Peter; Briggs, Richard; Leeming, David; White, Nathan; Cheese, Philip; DE&S MoD UK Team; Ordnance Test Solutions Ltd Team

    2017-06-01

    Fragment impact can pose a significant hazard to many systems containing explosives or propellants. Testing for this threat is most commonly carried out using a single fragment. However, it can be argued that an initial fragment strike (or strikes) could sensitise the energetic material to subsequent impacts, which may then lead to a more violent reaction than would have been predicted based upon single fragment studies. To explore this potential hazard we have developed the capability to launch 2 fragments from the same gun at a range of velocities, and achieve impacts on an acceptor charge with good control over the spatial and temporal separation of the strikes. In this paper we will describe in detail the experimental techniques we have used, both to achieve the dual fragment launch and observe the acceptor charge response. In addition, we will describe the results obtained against PBX filled explosive targets; discuss the mechanisms controlling the target response and their significance for vulnerability assessment. Results of these tests have clearly indicated the potential for detonation upon the second strike, at velocities well below those needed for shock initiation by a single fragment.

  15. Contrast and Raman spectroscopy study of single- and few-layered charge density wave material: 2H-TaSe2

    Science.gov (United States)

    Hajiyev, Parviz; Cong, Chunxiao; Qiu, Caiyu; Yu, Ting

    2013-01-01

    In this article, we report the first successful preparation of single- and few-layers of tantalum diselenide (2H-TaSe2) by mechanical exfoliation technique. Number of layers is confirmed by white light contrast spectroscopy and atomic force microscopy (AFM). Vibrational properties of the atomically thin layers of 2H-TaSe2 are characterized by micro-Raman spectroscopy. Room temperature Raman measurements demonstrate MoS2-like spectral features, which are reliable for thickness determination. E1g mode, usually forbidden in backscattering Raman configuration is observed in the supported TaSe2 layers while disappears in the suspended layers, suggesting that this mode may be enabled because of the symmetry breaking induced by the interaction with the substrate. A systematic in-situ low temperature Raman study, for the first time, reveals the existence of incommensurate charge density wave phase transition in single and double-layered 2H-TaSe2 as reflected by a sudden softening of the second-order broad Raman mode resulted from the strong electron-phonon coupling (Kohn anomaly). PMID:24005335

  16. Dual initiation strip charge apparatus and methods for making and implementing the same

    Science.gov (United States)

    Jakaboski, Juan-Carlos [Albuquerque, NM; Todd,; Steven, N [Rio Rancho, NM; Polisar, Stephen [Albuquerque, NM; Hughs, Chance [Tijeras, NM

    2011-03-22

    A Dual Initiation Strip Charge (DISC) apparatus is initiated by a single initiation source and detonates a strip of explosive charge at two separate contacts. The reflection of explosively induced stresses meet and create a fracture and breach a target along a generally single fracture contour and produce generally fragment-free scattering and no spallation. Methods for making and implementing a DISC apparatus provide numerous advantages over previous methods of creating explosive charges by utilizing steps for rapid prototyping; by implementing efficient steps and designs for metering consistent, repeatable, and controlled amount of high explosive; and by utilizing readily available materials.

  17. First Measurement of the Muon Neutrino Charged Current Single Pion Production Cross Section on Water with the T2K Near Detector

    CERN Document Server

    Abe, K.

    2017-01-26

    The T2K off-axis near detector, ND280, is used to make the first differential cross section measurements of muon neutrino charged current single positive pion production on a water target at energies ${\\sim}0.8$~GeV. The differential measurements are presented as a function of muon and pion kinematics, in the restricted phase-space defined by $p_{\\pi^+}>200$MeV/c, $p_{\\mu^-}>200$MeV/c, $\\cos \\theta_{\\pi^+}>0.3$ and $\\cos \\theta_{\\mu^-}>0.3$. The total flux integrated $\

  18. Production of fungal and bacterial growth modulating secondary metabolites is widespread among mycorrhiza-associated streptomycetes

    Science.gov (United States)

    2012-01-01

    Background Studies on mycorrhiza associated bacteria suggest that bacterial-fungal interactions play important roles during mycorrhiza formation and affect plant health. We surveyed Streptomyces Actinobacteria, known as antibiotic producers and antagonists of fungi, from Norway spruce mycorrhizas with predominantly Piloderma species as the fungal partner. Results Fifteen Streptomyces isolates exhibited substantial variation in inhibition of tested mycorrhizal and plant pathogenic fungi (Amanita muscaria, Fusarium oxysporum, Hebeloma cylindrosporum, Heterobasidion abietinum, Heterobasidion annosum, Laccaria bicolor, Piloderma croceum). The growth of the mycorrhiza-forming fungus Laccaria bicolor was stimulated by some of the streptomycetes, and Piloderma croceum was only moderately affected. Bacteria responded to the streptomycetes differently than the fungi. For instance the strain Streptomyces sp. AcM11, which inhibited most tested fungi, was less inhibitory to bacteria than other tested streptomycetes. The determined patterns of Streptomyces-microbe interactions were associated with distinct patterns of secondary metabolite production. Notably, potentially novel metabolites were produced by strains that were less antagonistic to fungi. Most of the identified metabolites were antibiotics (e.g. cycloheximide, actiphenol) and siderophores (e.g. ferulic acid, desferroxiamines). Plant disease resistance was activated by a single streptomycete strain only. Conclusions Mycorrhiza associated streptomycetes appear to have an important role in inhibiting the growth of fungi and bacteria. Additionally, our study indicates that the Streptomyces strains, which are not general antagonists of fungi, may produce still un-described metabolites. PMID:22852578

  19. Charge diffusion and the butterfly effect in striped holographic matter

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Andrew [Department of Physics, Harvard University,Cambridge, MA 02138 (United States); Department of Physics, Stanford University,Stanford, CA 94305 (United States); Steinberg, Julia [Department of Physics, Harvard University,Cambridge, MA 02138 (United States)

    2016-10-26

    Recently, it has been proposed that the butterfly velocity — a speed at which quantum information propagates — may provide a fundamental bound on diffusion constants in dirty incoherent metals. We analytically compute the charge diffusion constant and the butterfly velocity in charge-neutral holographic matter with long wavelength “hydrodynamic' disorder in a single spatial direction. In this limit, we find that the butterfly velocity does not set a sharp lower bound for the charge diffusion constant.

  20. Charge diffusion and the butterfly effect in striped holographic matter

    International Nuclear Information System (INIS)

    Lucas, Andrew; Steinberg, Julia

    2016-01-01

    Recently, it has been proposed that the butterfly velocity — a speed at which quantum information propagates — may provide a fundamental bound on diffusion constants in dirty incoherent metals. We analytically compute the charge diffusion constant and the butterfly velocity in charge-neutral holographic matter with long wavelength “hydrodynamic' disorder in a single spatial direction. In this limit, we find that the butterfly velocity does not set a sharp lower bound for the charge diffusion constant.

  1. Full counting statistics of a charge pump in the Coulomb blockade regime

    Science.gov (United States)

    Andreev, A. V.; Mishchenko, E. G.

    2001-12-01

    We study full charge counting statistics (FCCS) of a charge pump based on a nearly open single electron transistor. The problem is mapped onto an exactly soluble problem of a nonequilibrium g=1/2 Luttinger liquid with an impurity. We obtain an analytic expression for the generating function of the transmitted charge for an arbitrary pumping strength. Although this model contains fractionally charged excitations only integer transmitted charges can be observed. In the weak pumping limit FCCS correspond to a Poissonian transmission of particles with charge e*=e/2 from which all events with odd numbers of transferred particles are excluded.

  2. Charge collection and SEU mechanisms

    Science.gov (United States)

    Musseau, O.

    1994-01-01

    In the interaction of cosmic ions with microelectronic devices a dense electron-hole plasma is created along the ion track. Carriers are separated and transported by the electric field and under the action of the concentration gradient. The subsequent collection of these carriers induces a transient current at some electrical node of the device. This "ionocurrent" (single ion induced current) acts as any electrical perturbation in the device, propagating in the circuit and inducing failures. In bistable systems (registers, memories) the stored data can be upset. In clocked devices (microprocessors) the parasitic perturbation may propagate through the device to the outputs. This type of failure only effects the information, and do not degrade the functionally of the device. The purpose of this paper is to review the mechanisms of single event upset in microelectronic devices. Experimental and theoretical results are presented, and actual questions and problems are discussed. A brief introduction recalls the creation of the dense plasma of electron-hole pairs. The basic processes for charge collection in a simple np junction (drift and diffusion) are presented. The funneling-field effect is discussed and experimental results are compared to numerical simulations and semi-empirical models. Charge collection in actual microelectronic structures is then presented. Due to the parasitic elements, coupling effects are observed. Geometrical effects, in densely packed structures, results in multiple errors. Electronic couplings are due to the carriers in excess, acting as minority carriers, that trigger parasitic bipolar transistors. Single event upset of memory cells is discussed, based on numerical and experimental data. The main parameters for device characterization are presented. From the physical interpretation of charge collection mechanisms, the intrinsic sensitivity of various microelectronic technologies is determined and compared to experimental data. Scaling laws

  3. Charging of insulators by multiply-charged-ion impact probed by slowing down of fast binary-encounter electrons

    Science.gov (United States)

    de Filippo, E.; Lanzanó, G.; Amorini, F.; Cardella, G.; Geraci, E.; Grassi, L.; La Guidara, E.; Lombardo, I.; Politi, G.; Rizzo, F.; Russotto, P.; Volant, C.; Hagmann, S.; Rothard, H.

    2010-12-01

    The interaction of ion beams with insulators leads to charging-up phenomena, which at present are under investigation in connection with guiding phenomena in nanocapillaries with possible application in nanofocused beams. We studied the charging dynamics of insulating foil targets [Mylar, polypropylene (PP)] irradiated with swift ion beams (C, O, Ag, and Xe at 40, 23, 40, and 30 MeV/u, respectively) via the measurement of the slowing down of fast binary-encounter electrons. Also, sandwich targets (Mylar covered with a thin Au layer on both surfaces) and Mylar with Au on only one surface were used. Fast-electron spectra were measured by the time-of-flight method at the superconducting cyclotron of Laboratori Nazionali del Sud (LNS) Catania. The charge buildup leads to target-material-dependent potentials of the order of 6.0 kV for Mylar and 2.8 kV for PP. The sandwich targets, surprisingly, show the same behavior as the insulating targets, whereas a single Au layer on the electron and ion exit side strongly suppresses the charging phenomenon. The accumulated number of projectiles needed for charging up is inversely proportional to electronic energy loss. Thus, the charging up is directly related to emission of secondary electrons.

  4. Charging of insulators by multiply-charged-ion impact probed by slowing down of fast binary-encounter electrons

    International Nuclear Information System (INIS)

    De Filippo, E.; Lanzano, G.; Cardella, G.; Amorini, F.; Geraci, E.; Grassi, L.; Politi, G.; La Guidara, E.; Lombardo, I.; Rizzo, F.; Russotto, P.; Volant, C.; Hagmann, S.; Rothard, H.

    2010-01-01

    The interaction of ion beams with insulators leads to charging-up phenomena, which at present are under investigation in connection with guiding phenomena in nanocapillaries with possible application in nanofocused beams. We studied the charging dynamics of insulating foil targets [Mylar, polypropylene (PP)] irradiated with swift ion beams (C, O, Ag, and Xe at 40, 23, 40, and 30 MeV/u, respectively) via the measurement of the slowing down of fast binary-encounter electrons. Also, sandwich targets (Mylar covered with a thin Au layer on both surfaces) and Mylar with Au on only one surface were used. Fast-electron spectra were measured by the time-of-flight method at the superconducting cyclotron of Laboratori Nazionali del Sud (LNS) Catania. The charge buildup leads to target-material-dependent potentials of the order of 6.0 kV for Mylar and 2.8 kV for PP. The sandwich targets, surprisingly, show the same behavior as the insulating targets, whereas a single Au layer on the electron and ion exit side strongly suppresses the charging phenomenon. The accumulated number of projectiles needed for charging up is inversely proportional to electronic energy loss. Thus, the charging up is directly related to emission of secondary electrons.

  5. Conduction channels at finite bias in single-atom gold contacts

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Kobayashi, Nobuhiko; Tsukada, Masaru

    1999-01-01

    We consider the effect of a finite voltage bias on the conductance of single-atom gold contacts. We employ a nonorthogonal spn-tight-binding Hamiltonian combined with a local charge neutrality assumption. The conductance and charge distributions for finite bias are calculated using the nonequilib......We consider the effect of a finite voltage bias on the conductance of single-atom gold contacts. We employ a nonorthogonal spn-tight-binding Hamiltonian combined with a local charge neutrality assumption. The conductance and charge distributions for finite bias are calculated using...... of the eigenchannels projected onto tight-binding orbitals. We find a single almost fully transmitting channel with mainly s character for low bias while for high bias this channel becomes less transmitting and additional channels involving only d orbitals start to conduct....

  6. Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, Winfried, E-mail: kessler@helmholtz-muenchen.de [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Numtip, Wanwiwa [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Völkel, Wolfgang; Seckin, Elcim [Department of Chemical Safety and Toxicology, Bavarian Health and Food Safety Authority, Pfarrstrasse 3, D-80538 München (Germany); Csanády, György A. [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Institut für Toxikologie und Umwelthygiene, Technische Universität München, München (Germany); Pütz, Christian [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); and others

    2012-10-15

    The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

  7. O--H charge exchange in cold, dense, hydrogen plasmas

    International Nuclear Information System (INIS)

    Cohen, S.A.; Dylla, H.F.

    1977-05-01

    It is pointed out that the accidentally resonant charge exchange reaction, O + + H 0 reverse arrows O 0 + H + , is an important mechanism for causing the loss of singly charged oxygen ions from oxygen contaminated hydrogen plasmas. Results of a Monte Carlo simulation are presented which show that the fraction of oxygen lost because of charge exchange exceeds 1 / 3 when the parameters n/sub e/ approx. 10 13 cm -3 , n/sub H//sup o/ approx. 10 11 cm -3 and T/sub e/ approx. 3 eV are attained

  8. 21 CFR 862.3250 - Cocaine and cocaine metabolite test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cocaine and cocaine metabolite test system. 862... Test Systems § 862.3250 Cocaine and cocaine metabolite test system. (a) Identification. A cocaine and cocaine metabolite test system is a device intended to measure cocaine and a cocaine metabolite...

  9. Urinary excretion of androgen metabolites, comparison with excretion of radioactive metabolites after injection of (4-/sup 14/C)testosterone. Influence of age

    Energy Technology Data Exchange (ETDEWEB)

    Deslypere, J P; Sayed, A; Vermeulen, A [Department of Internal Medicine, Section of Endocrinology, State University Academic Hospital, De Pintelaan, 135, Ghent, Belgium; Wiers, P W [Department of Internal Medicine, Section of Pneumology, State University Academic Hospital, The Netherlands

    1981-01-01

    The influence of age on the metabolic pattern of (4-/sup 14/C)testosterone was studied in 20 young and 8 elderly males and compared to the metabolic pattern of endogenous androgens; the latter was also studied in 16 young and 8 elderly women. In both young and elderly males, androsterone and aetiocholanolone glucuronide represent 65% of (4-/sup 14/C)testosterone metabolites: together with their suephoconjugates as well as with 5..cap alpha..- and 5..beta..-androstane-3..cap alpha.., 17..beta..-diol they represent even more than 75% of total urinary metabolites. The 5..cap alpha../5..beta.. ratio of metabolites of (4-/sup 14/C)testosterone was significantly (P<0.01) correlated with the 5..cap alpha../5..beta.. ratio of the metabolites of the endogenous androgens, mainly dehydroepiandrosterone and androstenedione. The 5..cap alpha../5..beta.. ratio of (4-/sup 14/C)testosterone metabolites was generally higher than the ratio of metabolites of endogenous androgens, suggesting that the transformation of T to ring A saturated metabolites occurs at least partially in another compartment than the transformation of DHEA to these metabolites. For both (4-/sup 14/C)testosterone and endogenous androgen metabolites we observed a statistically significant reduction of the 5..cap alpha../5..beta.. ratio with age, a general phenomenon in both males and females. This reduction concern also 11-OH-androst-4-ene-3.17-dione metabolism. Neither sex hormone levels, nor specific binding seems to determine this age dependent shift; neither is there convincing evidence for latent hypothyroisism or liver dysfunction in the elderly. An age associated primary decrease of the 5..cap alpha..-reductase activity seems the most likely explanation.

  10. Threshold voltage variation depending on single grain boundary and stored charges in an adjacent cell for vertical silicon–oxide–nitride–oxide–silicon NAND flash memory

    Science.gov (United States)

    Oh, Hyeongwan; Kim, Jiwon; Baek, Rock-Hyun; Lee, Jeong-Soo

    2018-04-01

    The effects of single grain boundary (SGB) position and stored electron charges in an adjacent cell in silicon–oxide–nitride–oxide–silicon (SONOS) structures on the variations of threshold voltage (V th) were investigated using technology computer-aided design (TCAD) simulation. As the bit line voltage increases, the SGB position causing the maximum V th variation was shifted from the center to the source side in the channel, owing to the drain-induced grain barrier lowering effect. When the SGB is located in the spacer region, the potential interaction from both the SGB and the stored electron charges in the adjacent cell becomes significant and thus resulting in larger V th variation. In contrast, when the SGB is located at the center of the channel, the peak position of potential barrier is shifted to the center, so that the influence of the adjacent cell is diminished. As the gate length is scaled down to 20 nm, the influence of stored charges in adjacent cells becomes significant, resulting in larger V th variations.

  11. Distribution of trans-resveratrol and its metabolites after acute or sustained administration in mouse heart, brain, and liver.

    Science.gov (United States)

    Menet, Marie-Claude; Baron, Stephanie; Taghi, Meryam; Diestra, Remi; Dargère, Delphine; Laprévote, Olivier; Nivet-Antoine, Valérie; Beaudeux, Jean-Louis; Bédarida, Tatiana; Cottart, Charles-Henry

    2017-08-01

    Trans-resveratrol is widely studied for its potentially beneficial effects on numerous disorders. It is rapidly metabolized and its metabolites can exhibit biological activity. The present study aimed to investigate whether acute or sustained trans-resveratrol administration impacted on the distribution of trans-resveratrol and its metabolites in brain, heart, and liver. We used ultra-HPLC quadrupole-TOF (UHPLC-Q-TOF) in a full-scan mode to identify and assess large numbers of resveratrol metabolites. For acute intake, mice were overfed with a single dose of trans-resveratrol (150 mg/kg) and organs were collected after 30 and 60 min. For sustained intake, trans-resveratrol was given in the chow (0.04% w/w corresponding to 40 mg/kg/day), and plasma and the organs were collected after 3 months of this resveratrol diet. We found that trans-resveratrol-3-O-glucuronide and resveratrol-3-sulfate were the main metabolites found after acute intake, and free trans-resveratrol (in the brain and heart) and dihydroresveratrol derivatives were found after sustained administration CONCLUSIONS: Our results show notable differences between acute and sustained administration of trans-resveratrol and distribution of trans-resveratrol and its metabolites in mouse heart, brain, and liver. The results suggest a strategy for development of galenic forms of resveratrol. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. SECONDARY METABOLITES FROM MARINE PENICILLIUM BREVICOMPACTUM

    OpenAIRE

    ROVIROSA, JUANA; DIAZ-MARRERO, ANA; DARIAS, JOSE; PAINEMAL, KARIN; SAN MARTIN, AURELIO

    2006-01-01

    In a screening of Basidiomycete cultures isolated from marine invertebrates collected along the Chilean coastline for the production of antibiotics we identified a Penicillium brevicompactum strain as a producer of metabolites inhibiting the growth of bacteria and fungi. Bioactivity guided purification resulted in the isolation of four known metabolites. Their structures were elucidated by spectroscopic methods.

  13. Plant metabolites and nutritional quality of vegetables.

    Science.gov (United States)

    Hounsome, N; Hounsome, B; Tomos, D; Edwards-Jones, G

    2008-05-01

    Vegetables are an important part of the human diet and a major source of biologically active substances such as vitamins, dietary fiber, antioxidants, and cholesterol-lowering compounds. Despite a large amount of information on this topic, the nutritional quality of vegetables has not been defined. Historically, the value of many plant nutrients and health-promoting compounds was discovered by trial and error. By the turn of the century, the application of chromatography, mass spectrometry, infrared spectrometry, and nuclear magnetic resonance allowed quantitative and qualitative measurements of a large number of plant metabolites. Approximately 50000 metabolites have been elucidated in plants, and it is predicted that the final number will exceed 200000. Most of them have unknown function. Metabolites such as carbohydrates, organic and amino acids, vitamins, hormones, flavonoids, phenolics, and glucosinolates are essential for plant growth, development, stress adaptation, and defense. Besides the importance for the plant itself, such metabolites determine the nutritional quality of food, color, taste, smell, antioxidative, anticarcinogenic, antihypertension, anti-inflammatory, antimicrobial, immunostimulating, and cholesterol-lowering properties. This review is focused on major plant metabolites that characterize the nutritional quality of vegetables, and methods of their analysis.

  14. β-Orcinol Metabolites from the Lichen Hypotrachyna revoluta

    Directory of Open Access Journals (Sweden)

    Panagiota Papadopoulou

    2007-05-01

    Full Text Available Four new β-orcinol metabolites, hypotrachynic acid (1, deoxystictic acid (2, cryptostictinolide (3 and 8 ́-methylconstictic acid (4 along with the metabolites 8 ́-methylstictic acid (5, 8 ́-methylmenegazziaic acid (6, stictic acid (7, 8 ́-ethylstictic acid (8 and atranorin (9, that have been previously described, were isolated for the first time from the tissue extracts of the lichen Hypotrachyna revoluta (Flörke Hale. The structures of the new metabolites were elucidated on the basis of extensive spectroscopic analyses. Radical scavenging activity (RSA of the metabolites isolated in adequate amounts, was evaluated using luminol chemiluminescence and comparison with Trolox®.

  15. Analysis of Intracellular Metabolites from Microorganisms: Quenching and Extraction Protocols.

    Science.gov (United States)

    Pinu, Farhana R; Villas-Boas, Silas G; Aggio, Raphael

    2017-10-23

    Sample preparation is one of the most important steps in metabolome analysis. The challenges of determining microbial metabolome have been well discussed within the research community and many improvements have already been achieved in last decade. The analysis of intracellular metabolites is particularly challenging. Environmental perturbations may considerably affect microbial metabolism, which results in intracellular metabolites being rapidly degraded or metabolized by enzymatic reactions. Therefore, quenching or the complete stop of cell metabolism is a pre-requisite for accurate intracellular metabolite analysis. After quenching, metabolites need to be extracted from the intracellular compartment. The choice of the most suitable metabolite extraction method/s is another crucial step. The literature indicates that specific classes of metabolites are better extracted by different extraction protocols. In this review, we discuss the technical aspects and advancements of quenching and extraction of intracellular metabolite analysis from microbial cells.

  16. Activation of the Silent Secondary Metabolite Production by Introducing Neomycin-Resistance in a Marine-Derived Penicillium purpurogenum G59

    Directory of Open Access Journals (Sweden)

    Chang-Jing Wu

    2015-04-01

    Full Text Available Introduction of neomycin-resistance into a marine-derived, wild-type Penicillium purpurogenum G59 resulted in activation of silent biosynthetic pathways for the secondary metabolite production. Upon treatment of G59 spores with neomycin and dimethyl sulfoxide (DMSO, a total of 56 mutants were obtained by single colony isolation. The acquired resistance of mutants to neomycin was testified by the resistance test. In contrast to the G59 strain, the EtOAc extracts of 28 mutants inhibited the human cancer K562 cells, indicating that the 28 mutants have acquired the capability to produce bioactive metabolites. HPLC-photodiode array detector (PDAD-UV and HPLC-electron spray ionization (ESI-MS analyses further indicated that diverse secondary metabolites have been newly produced in the bioactive mutant extracts. Followed isolation and characterization demonstrated that five bioactive secondary metabolites, curvularin (1, citrinin (2, penicitrinone A (3, erythro-23-O-methylneocyclocitrinol (4 and 22E-7α-methoxy-5α, 6α-epoxyergosta-8(14,22-dien-3β-ol (5, were newly produced by a mutant, 4-30, compared to the G59 strain. All 1–5 were also not yet found in the secondary metabolites of other wild type P. purpurogenum strains. Compounds 1–5 inhibited human cancer K562, HL-60, HeLa and BGC-823 cells to varying extents. Both present bioassays and chemical investigations demonstrated that the introduction of neomycin-resistance into the marine-derived fungal G59 strain could activate silent secondary metabolite production. The present work not only extended the previous DMSO-mediated method for introducing drug-resistance in fungi both in DMSO concentrations and antibiotics, but also additionally exemplified effectiveness of this method for activating silent fungal secondary metabolites. This method could be applied to other fungal isolates to elicit their metabolic potentials to investigate secondary metabolites from silent biosynthetic pathways.

  17. Quantacell: powerful charging of quantum batteries

    International Nuclear Information System (INIS)

    Binder, Felix C; Vinjanampathy, Sai; Modi, Kavan; Goold, John

    2015-01-01

    We study the problem of charging a quantum battery in finite time. We demonstrate an analytical optimal protocol for the case of a single qubit. Extending this analysis to an array of N qubits, we demonstrate that an N-fold advantage in power per qubit can be achieved when global operations are permitted. The exemplary analytic argument for this quantum advantage in the charging power is backed up by numerical analysis using optimal control techniques. It is demonstrated that the quantum advantage for power holds when, with cyclic operation in mind, initial and final states are required to be separable. (paper)

  18. Net charge fluctuations and local charge compensation

    International Nuclear Information System (INIS)

    Fu Jinghua

    2006-01-01

    We propose net charge fluctuation as a measure of local charge correlation length. It is demonstrated that, in terms of a schematic multiperipheral model, net charge fluctuation satisfies the same Quigg-Thomas relation as satisfied by charge transfer fluctuation. Net charge fluctuations measured in finite rapidity windows depend on both the local charge correlation length and the size of the observation window. When the observation window is larger than the local charge correlation length, the net charge fluctuation only depends on the local charge correlation length, while forward-backward charge fluctuations always have strong dependence on the observation window size. Net charge fluctuations and forward-backward charge fluctuations measured in the present heavy ion experiments show characteristic features similar to those from multiperipheral models. But the data cannot all be understood within this simple model

  19. Local charge exchange of He{sup +} ions at Aluminum surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Riccardi, P., E-mail: pierfrancesco.riccardi@fis.unical.it [Dipartimento di Fisica, Università della Calabria and INFN – Gruppo collegato di Cosenza, Via P. Bucci cubo 33C, Arcavacata di Rende, Cosenza (Italy); Sindona, A. [Dipartimento di Fisica, Università della Calabria and INFN – Gruppo collegato di Cosenza, Via P. Bucci cubo 33C, Arcavacata di Rende, Cosenza (Italy); Dukes, C.A. [Laboratory for Astrophysics and Surface Physics, Materials Science and Engineering University of Virginia, Charlottesville, VA 22904 (United States)

    2017-04-04

    We report on experiments designed to observe the correlation between the autoionization of doubly excited helium atoms and the Auger decay of 2p vacancies in Al. The autoionizing states are formed when incident He{sup +*} and He{sup ++} are neutralized by resonant electron capture at the surface. 2p excitation in Al occurs in dielectronic charge transfer during the close encounter of an excited helium ion and an Al atom. These results clarify the mechanism for Al-2p excitation in the case of singly charged ground state He{sup +}(1s) ion impact, where the dielectronic transition occurs after promotion of the 1s electron of incoming ions. - Highlights: • We observe the correlation between autoionization of doubly excited helium atoms and the Auger decay of 2p vacancies in Al. • 2p excitation in Al occurs in dielectronic charge transfer during the close encounter of an excited helium ion and an Al atom. • These results clarify the mechanism for Al-2p excitation in the case of singly charged ground state He{sup +}(1s) ion impact.

  20. Marine metabolites: The sterols of soft coral

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, N.S.; Krishna, M.S.; Pasha, Sk.G.; Rao, T.S.P.; Venkateswarlu, Y.; Parameswaran, P.S.

    Sterols constitute a major group of secondary metabolites of soft corals. Several of these compounds have the 'usual' 3 beta-hydroxy, delta sup(5) (or delta sup(0)) cholestane skeleton, a large number of these metabolites are polar sterols...

  1. MIDAS: a database-searching algorithm for metabolite identification in metabolomics.

    Science.gov (United States)

    Wang, Yingfeng; Kora, Guruprasad; Bowen, Benjamin P; Pan, Chongle

    2014-10-07

    A database searching approach can be used for metabolite identification in metabolomics by matching measured tandem mass spectra (MS/MS) against the predicted fragments of metabolites in a database. Here, we present the open-source MIDAS algorithm (Metabolite Identification via Database Searching). To evaluate a metabolite-spectrum match (MSM), MIDAS first enumerates possible fragments from a metabolite by systematic bond dissociation, then calculates the plausibility of the fragments based on their fragmentation pathways, and finally scores the MSM to assess how well the experimental MS/MS spectrum from collision-induced dissociation (CID) is explained by the metabolite's predicted CID MS/MS spectrum. MIDAS was designed to search high-resolution tandem mass spectra acquired on time-of-flight or Orbitrap mass spectrometer against a metabolite database in an automated and high-throughput manner. The accuracy of metabolite identification by MIDAS was benchmarked using four sets of standard tandem mass spectra from MassBank. On average, for 77% of original spectra and 84% of composite spectra, MIDAS correctly ranked the true compounds as the first MSMs out of all MetaCyc metabolites as decoys. MIDAS correctly identified 46% more original spectra and 59% more composite spectra at the first MSMs than an existing database-searching algorithm, MetFrag. MIDAS was showcased by searching a published real-world measurement of a metabolome from Synechococcus sp. PCC 7002 against the MetaCyc metabolite database. MIDAS identified many metabolites missed in the previous study. MIDAS identifications should be considered only as candidate metabolites, which need to be confirmed using standard compounds. To facilitate manual validation, MIDAS provides annotated spectra for MSMs and labels observed mass spectral peaks with predicted fragments. The database searching and manual validation can be performed online at http://midas.omicsbio.org.

  2. Charge separation at nanoscale interfaces: energy-level alignment including two-quasiparticle interactions.

    Science.gov (United States)

    Li, Huashan; Lin, Zhibin; Lusk, Mark T; Wu, Zhigang

    2014-10-21

    The universal and fundamental criteria for charge separation at interfaces involving nanoscale materials are investigated. In addition to the single-quasiparticle excitation, all the two-quasiparticle effects including exciton binding, Coulomb stabilization, and exciton transfer are considered, which play critical roles on nanoscale interfaces for optoelectronic applications. We propose a scheme allowing adding these two-quasiparticle interactions on top of the single-quasiparticle energy level alignment for determining and illuminating charge separation at nanoscale interfaces. Employing the many-body perturbation theory based on Green's functions, we quantitatively demonstrate that neglecting or simplifying these crucial two-quasiparticle interactions using less accurate methods is likely to predict qualitatively incorrect charge separation behaviors at nanoscale interfaces where quantum confinement dominates.

  3. Production of a single new charged heavy lepton in DELPHI/LEP

    CERN Document Server

    Do Vale, M A B; De Paula, L S

    1999-01-01

    The search for a new charged heavy lepton predicted by some extended models is presented. The data used were collected by the detector DELPHI/LEP at 1994 operating with a center of mass energy near the Z /sup 0/ mass and correspond to a total luminosity of 40 pb/sup -1/. (1 refs).

  4. Quantum theory of space charge limited current in solids

    Energy Technology Data Exchange (ETDEWEB)

    González, Gabriel, E-mail: gabriel.gonzalez@uaslp.mx [Cátedras Conacyt, Universidad Autónoma de San Luis Potosí, San Luis Potosí 78000, Mexico and Coordinación para la Innovación y la Aplicación de la Ciencia y la Tecnología, Universidad Autónoma de San Luis Potosí, San Luis Potosí 78000 (Mexico)

    2015-02-28

    We present a quantum model of space charge limited current transport inside trap-free solids with planar geometry in the mean field approximation. We use a simple transformation which allows us to find the exact analytical solution for the steady state current case. We use our approach to find a Mott-Gurney like behavior and the mobility for single charge carriers in the quantum regime in solids.

  5. Charged Higgs Beyond the MSSM at the LHC

    CERN Document Server

    Huitu, Katri

    2017-01-01

    The charged Higgs boson is an inevitable particle in supersymmetric models, both in the minimal version and in extensions. It is also a particle, which may have different decay channels depending on the scalar representations in the model, and thus it may help in identifying the model. In this talk I will consider the simplest singlet and triplet extensions of the minimal supersymmetric standard model, and in particular, describe some smoking gun signals of charged Higgs at the LHC collider. Then I will move on to supersymmetric left-right models, in which neutrino masses are naturally generated and which have several dark matter candidates, in addition to possibly solving both the strong and weak CP-problems. I will discuss the charged Higgses, both singly and doubly charged, in such models.

  6. Formation of the accumulative human metabolite and human-specific glutathione conjugate of diclofenac in TK-NOG chimeric mice with humanized livers.

    Science.gov (United States)

    Kamimura, Hidetaka; Ito, Satoshi; Nozawa, Kohei; Nakamura, Shota; Chijiwa, Hiroyuki; Nagatsuka, Shin-ichiro; Kuronuma, Miyuki; Ohnishi, Yasuyuki; Suemizu, Hiroshi; Ninomiya, Shin-ichi

    2015-03-01

    3'-Hydroxy-4'-methoxydiclofenac (VI) is a human-specific metabolite known to accumulate in the plasma of patients after repeated administration of diclofenac sodium. Diclofenac also produces glutathione-conjugated metabolites, some of which are human-specific. In the present study, we investigated whether these metabolites could be generated in humanized chimeric mice produced from TK-NOG mice. After a single oral administration of diclofenac to humanized mice, the unchanged drug in plasma peaked at 0.25 hour and then declined with a half-life (t1/2) of 2.4 hours. 4'-Hydroxydiclofenac (II) and 3'-hydroxydiclofenac also peaked at 0.25 hour and were undetectable within 24 hours. However, VI peaked at 8 hours and declined with a t1/2 of 13 hours. When diclofenac was given once per day, peak and trough levels of VI reached plateau within 3 days. Studies with administration of II suggested VI was generated via II as an intermediate. Among six reported glutathione-conjugated metabolites of diclofenac, M1 (5-hydroxy-4-(glutathion-S-yl)diclofenac) to M6 (2'-(glutathion-S-yl)monoclofenac), we found three dichlorinated conjugates [M1, M2 (4'-hydroxy-3'-(glutathion-S-yl)diclofenac), and M3 (5-hydroxy-6-(glutathion-S-yl)diclofenac)], and a single monochlorinated conjugate [M4 (2'-hydroxy-3'-(glutathion-S-yl)monoclofenac) or M5 (4'-hydroxy-2'-(glutathion-S-yl)monoclofenac)], in the bile of humanized chimeric mice. M4 and M5 are positional isomers and have been previously reported as human-specific in vitro metabolites likely generated via arene oxide and quinone imine-type intermediates, respectively. The biliary monochlorinated metabolite exhibited the same mass spectrum as those of M4 and M5, and we discuss whether this conjugate corresponded to M4 or M5. Overall, humanized TK-NOG chimeric mice were considered to be a functional tool for the study of drug metabolism of diclofenac in humans. Copyright © 2015 by The American Society for Pharmacology and Experimental

  7. 40 CFR 159.179 - Metabolites, degradates, contaminants, and impurities.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Metabolites, degradates, contaminants.../Benefit Information § 159.179 Metabolites, degradates, contaminants, and impurities. (a) Metabolites and... degradation of less than 10 percent in a 30-day period. (b) Contaminants and impurities. The presence in any...

  8. New instrument for tribocharge measurement due to single particle impacts

    International Nuclear Information System (INIS)

    Watanabe, Hideo; Ghadiri, Mojtaba; Matsuyama, Tatsushi; Ding Yulong; Pitt, Kendal G.

    2007-01-01

    During particulate solid processing, particle-particle and particle-wall collisions can generate electrostatic charges. This may lead to a variety of problems ranging from fire and explosion hazards to segregation, caking, and blocking. A fundamental understanding of the particle charging in such situations is therefore essential. For this purpose we have developed a new device that can measure charge transfer due to impact between a single particle and a metal plate. The device consists of an impact test system and two sets of Faraday cage and preamplifier for charge measurement. With current amplifiers, high-resolution measurements of particle charges of approximately 1 and 10 fC have been achieved before and after the impact, respectively. The device allows charge measurements of single particles with a size as small as ∼100 μm impacting on the target at different incident angles with a velocity up to about 80 m/s. Further analyses of the charge transfer as a function of particle initial charge define an equilibrium charge, i.e., an initial charge level prior to impact for which no net charge transfer would occur as a result of impact

  9. Analysis of Intracellular Metabolites from Microorganisms: Quenching and Extraction Protocols

    Directory of Open Access Journals (Sweden)

    Farhana R. Pinu

    2017-10-01

    Full Text Available Sample preparation is one of the most important steps in metabolome analysis. The challenges of determining microbial metabolome have been well discussed within the research community and many improvements have already been achieved in last decade. The analysis of intracellular metabolites is particularly challenging. Environmental perturbations may considerably affect microbial metabolism, which results in intracellular metabolites being rapidly degraded or metabolized by enzymatic reactions. Therefore, quenching or the complete stop of cell metabolism is a pre-requisite for accurate intracellular metabolite analysis. After quenching, metabolites need to be extracted from the intracellular compartment. The choice of the most suitable metabolite extraction method/s is another crucial step. The literature indicates that specific classes of metabolites are better extracted by different extraction protocols. In this review, we discuss the technical aspects and advancements of quenching and extraction of intracellular metabolite analysis from microbial cells.

  10. Identification of natural metabolites in mixture: a pattern recognition strategy based on (13)C NMR.

    Science.gov (United States)

    Hubert, Jane; Nuzillard, Jean-Marc; Purson, Sylvain; Hamzaoui, Mahmoud; Borie, Nicolas; Reynaud, Romain; Renault, Jean-Hugues

    2014-03-18

    Because of their highly complex metabolite profile, the chemical characterization of bioactive natural extracts usually requires time-consuming multistep purification procedures to achieve the structural elucidation of pure individual metabolites. The aim of the present work was to develop a dereplication strategy for the identification of natural metabolites directly within mixtures. Exploiting the polarity range of metabolites, the principle was to rapidly fractionate a multigram quantity of a crude extract by centrifugal partition extraction (CPE). The obtained fractions of simplified chemical composition were subsequently analyzed by (13)C NMR. After automatic collection and alignment of (13)C signals across spectra, hierarchical clustering analysis (HCA) was performed for pattern recognition. As a result, strong correlations between (13)C signals of a single structure within the mixtures of the fraction series were visualized as chemical shift clusters. Each cluster was finally assigned to a molecular structure with the help of a locally built (13)C NMR chemical shift database. The proof of principle of this strategy was achieved on a simple model mixture of commercially available plant secondary metabolites and then applied to a bark extract of the African tree Anogeissus leiocarpus Guill. & Perr. (Combretaceae). Starting from 5 g of this genuine extract, the fraction series was generated by CPE in only 95 min. (13)C NMR analyses of all fractions followed by pattern recognition of (13)C chemical shifts resulted in the unambiguous identification of seven major compounds, namely, sericoside, trachelosperogenin E, ellagic acid, an epimer mixture of (+)-gallocatechin and (-)-epigallocatechin, 3,3'-di-O-methylellagic acid 4'-O-xylopyranoside, and 3,4,3'-tri-O-methylflavellagic acid 4'-O-glucopyranoside.

  11. Investigation of metabolites for estimating blood deposition time.

    Science.gov (United States)

    Lech, Karolina; Liu, Fan; Davies, Sarah K; Ackermann, Katrin; Ang, Joo Ern; Middleton, Benita; Revell, Victoria L; Raynaud, Florence J; Hoveijn, Igor; Hut, Roelof A; Skene, Debra J; Kayser, Manfred

    2018-01-01

    Trace deposition timing reflects a novel concept in forensic molecular biology involving the use of rhythmic biomarkers for estimating the time within a 24-h day/night cycle a human biological sample was left at the crime scene, which in principle allows verifying a sample donor's alibi. Previously, we introduced two circadian hormones for trace deposition timing and recently demonstrated that messenger RNA (mRNA) biomarkers significantly improve time prediction accuracy. Here, we investigate the suitability of metabolites measured using a targeted metabolomics approach, for trace deposition timing. Analysis of 171 plasma metabolites collected around the clock at 2-h intervals for 36 h from 12 male participants under controlled laboratory conditions identified 56 metabolites showing statistically significant oscillations, with peak times falling into three day/night time categories: morning/noon, afternoon/evening and night/early morning. Time prediction modelling identified 10 independently contributing metabolite biomarkers, which together achieved prediction accuracies expressed as AUC of 0.81, 0.86 and 0.90 for these three time categories respectively. Combining metabolites with previously established hormone and mRNA biomarkers in time prediction modelling resulted in an improved prediction accuracy reaching AUCs of 0.85, 0.89 and 0.96 respectively. The additional impact of metabolite biomarkers, however, was rather minor as the previously established model with melatonin, cortisol and three mRNA biomarkers achieved AUC values of 0.88, 0.88 and 0.95 for the same three time categories respectively. Nevertheless, the selected metabolites could become practically useful in scenarios where RNA marker information is unavailable such as due to RNA degradation. This is the first metabolomics study investigating circulating metabolites for trace deposition timing, and more work is needed to fully establish their usefulness for this forensic purpose.

  12. Formation of charged particles in condensation aerosol generators used for inhalation studies

    International Nuclear Information System (INIS)

    Ramu, M.C.R.; Vohra, K.G.

    1976-01-01

    Formation of charged particles in a condensation aerosol generator has been studied using a charge collector and a mobility analyzer. Measurements carried out using the charge collector show that the number of charged particles increases with an increase in the particle diameter. The number of charged particles measured also depends on the thickness of the sodium chloride coating on the platinum wire used in the aerosol generator for the production of condensation nuclei. It was found that the charged particle concentration increases with decreasing coating thickness. Mobility measurements have shown that the particles are singly and doubly charged. It has been estimated that about 10% of the particles produced in the generator are charged. The mechanism of formation of charged particles in the aerosol generator has been briefly discussed. (author)

  13. Serum Metabolite Biomarkers Discriminate Healthy Smokers from COPD Smokers

    Science.gov (United States)

    Chen, Qiuying; Deeb, Ruba S.; Ma, Yuliang; Staudt, Michelle R.; Crystal, Ronald G.; Gross, Steven S.

    2015-01-01

    COPD (chronic obstructive pulmonary disease) is defined by a fixed expiratory airflow obstruction associated with disordered airways and alveolar destruction. COPD is caused by cigarette smoking and is the third greatest cause of mortality in the US. Forced expiratory volume in 1 second (FEV1) is the only validated clinical marker of COPD, but it correlates poorly with clinical features and is not sensitive enough to predict the early onset of disease. Using LC/MS global untargeted metabolite profiling of serum samples from a well-defined cohort of healthy smokers (n = 37), COPD smokers (n = 41) and non-smokers (n = 37), we sought to discover serum metabolic markers with known and/or unknown molecular identities that are associated with early-onset COPD. A total of 1,181 distinct molecular ions were detected in 95% of sera from all study subjects and 23 were found to be differentially-expressed in COPD-smokers vs. healthy-smokers. These 23 putative biomarkers were differentially-correlated with lung function parameters and used to generate a COPD prediction model possessing 87.8% sensitivity and 86.5% specificity. In an independent validation set, this model correctly predicted COPD in 8/10 individuals. These serum biomarkers included myoinositol, glycerophopshoinositol, fumarate, cysteinesulfonic acid, a modified version of fibrinogen peptide B (mFBP), and three doubly-charged peptides with undefined sequence that significantly and positively correlate with mFBP levels. Together, elevated levels of serum mFBP and additional disease-associated biomarkers point to a role for chronic inflammation, thrombosis, and oxidative stress in remodeling of the COPD airways. Serum metabolite biomarkers offer a promising and accessible window for recognition of early-stage COPD. PMID:26674646

  14. Ruta graveolens Extracts and Metabolites against Spodoptera frugiperda.

    Science.gov (United States)

    Ayil-Gutiérrez, Benjamin A; Villegas-Mendoza, Jesús M; Santes-Hernndez, Zuridai; Paz-González, Alma D; Mireles-Martínez, Maribel; Rosas-García, Ninfa M; Rivera, Gildardo

    2015-11-01

    The biological activity of Ruta graveolens leaf tissue extracts obtained with different solvents (ethyl acetate, ethanol, and water) and metabolites (psoralen, 2- undecanone and rutin) against Spodoptera frugiperda was evaluated. Metabolites levels in extracts were quantified by HPLC and GC. Ethyl acetate and ethanol extracts showed 94% and 78% mortality, respectively. Additionally, psoralen metabolite showed a high mortality as cypermethrin. Metabolite quantification in extracts shows the presence of 2-undecanone (87.9 µmoles mg(-1) DW), psoralen (3.6 µmoles mg(-1) DW) and rutin (0.001 pmoles mg(-1) DW). We suggest that these concentrations of 2-undecanone and psoralen in R. graveolens leaf tissue extracts could be responsible for S. frugiperda mortality.

  15. Modulation of nitrogen vacancy charge state and fluorescence in nanodiamonds using electrochemical potential.

    Science.gov (United States)

    Karaveli, Sinan; Gaathon, Ophir; Wolcott, Abraham; Sakakibara, Reyu; Shemesh, Or A; Peterka, Darcy S; Boyden, Edward S; Owen, Jonathan S; Yuste, Rafael; Englund, Dirk

    2016-04-12

    The negatively charged nitrogen vacancy (NV(-)) center in diamond has attracted strong interest for a wide range of sensing and quantum information processing applications. To this end, recent work has focused on controlling the NV charge state, whose stability strongly depends on its electrostatic environment. Here, we demonstrate that the charge state and fluorescence dynamics of single NV centers in nanodiamonds with different surface terminations can be controlled by an externally applied potential difference in an electrochemical cell. The voltage dependence of the NV charge state can be used to stabilize the NV(-) state for spin-based sensing protocols and provides a method of charge state-dependent fluorescence sensing of electrochemical potentials. We detect clear NV fluorescence modulation for voltage changes down to 100 mV, with a single NV and down to 20 mV with multiple NV centers in a wide-field imaging mode. These results suggest that NV centers in nanodiamonds could enable parallel optical detection of biologically relevant electrochemical potentials.

  16. Modulation of nitrogen vacancy charge state and fluorescence in nanodiamonds using electrochemical potential

    Science.gov (United States)

    Karaveli, Sinan; Gaathon, Ophir; Wolcott, Abraham; Sakakibara, Reyu; Shemesh, Or A.; Peterka, Darcy S.; Boyden, Edward S.; Owen, Jonathan S.; Yuste, Rafael; Englund, Dirk

    2016-04-01

    The negatively charged nitrogen vacancy (NV-) center in diamond has attracted strong interest for a wide range of sensing and quantum information processing applications. To this end, recent work has focused on controlling the NV charge state, whose stability strongly depends on its electrostatic environment. Here, we demonstrate that the charge state and fluorescence dynamics of single NV centers in nanodiamonds with different surface terminations can be controlled by an externally applied potential difference in an electrochemical cell. The voltage dependence of the NV charge state can be used to stabilize the NV- state for spin-based sensing protocols and provides a method of charge state-dependent fluorescence sensing of electrochemical potentials. We detect clear NV fluorescence modulation for voltage changes down to 100 mV, with a single NV and down to 20 mV with multiple NV centers in a wide-field imaging mode. These results suggest that NV centers in nanodiamonds could enable parallel optical detection of biologically relevant electrochemical potentials.

  17. Crystal growth of new charge-transfer salts based on π-conjugated donor molecules

    Energy Technology Data Exchange (ETDEWEB)

    Morherr, Antonia, E-mail: morherr@stud.uni-frankfurt.de [Physikalisches Institut, Goethe-Universität Frankfurt am Main, 60438 Frankfurt am Main (Germany); Witt, Sebastian [Physikalisches Institut, Goethe-Universität Frankfurt am Main, 60438 Frankfurt am Main (Germany); Chernenkaya, Alisa [Graduate School Materials Science in Mainz, 55128 Mainz (Germany); Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Bäcker, Jan-Peter [Physikalisches Institut, Goethe-Universität Frankfurt am Main, 60438 Frankfurt am Main (Germany); Schönhense, Gerd [Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Bolte, Michael [Institut für anorganische Chemie, Goethe-Universität Frankfurt am Main, 60438 Frankfurt am Main (Germany); Krellner, Cornelius [Physikalisches Institut, Goethe-Universität Frankfurt am Main, 60438 Frankfurt am Main (Germany)

    2016-09-01

    New charge transfer crystals of π-conjugated, aromatic molecules (phenanthrene and picene) as donors were obtained by physical vapor transport. The melting behavior, optimization of crystal growth and the crystal structure are reported for charge transfer salts with (fluorinated) tetracyanoquinodimethane (TCNQ-F{sub x}, x=0, 2, 4), which was used as acceptor material. The crystal structures were determined by single-crystal X-ray diffraction. Growth conditions for different vapor pressures in closed ampules were applied and the effect of these starting conditions for crystal size and quality is reported. The process of charge transfer was investigated by geometrical analysis of the crystal structure and by infrared spectroscopy on single crystals. With these three different acceptor strengths and the two sets of donor materials, it is possible to investigate the distribution of the charge transfer systematically. This helps to understand the charge transfer process in this class of materials with π-conjugated donor molecules.

  18. Single Molecule Nanoelectrochemistry in Electrical Junctions.

    Science.gov (United States)

    Nichols, Richard J; Higgins, Simon J

    2016-11-15

    It is now possible to reliably measure single molecule conductance in a wide variety of environments including organic liquids, ultrahigh vacuum, water, ionic liquids, and electrolytes. The most commonly used methods deploy scanning probe microscopes, mechanically formed break junctions, or lithographically formed nanogap contacts. Molecules are generally captured between a pair of facing electrodes, and the junction current response is measured as a function of bias voltage. Gating electrodes can also be added so that the electrostatic potential at the molecular bridge can be independently controlled by this third noncontacting electrode. This can also be achieved in an electrolytic environment using a four-electrode bipotentiostatic configuration, which allows independent electrode potential control of the two contacting electrodes. This is commonly realized using an electrochemical STM and enables single molecule electrical characterization as a function of electrode potential and redox state of the molecular bridge. This has emerged as a powerful tool in modern interfacial electrochemistry and nanoelectrochemistry for studying charge transport across single molecules as a function of electrode potential and the electrolytic environments. Such measurements are possible in electrolytes ranging from aqueous buffers to nonaqueous ionic liquids. In this Account, we illustrate a number of examples of single molecule electrical measurements under electrode potential control use a scanning tunneling microscope (STM) and demonstrate how these can help in the understanding of charge transport in single molecule junctions. Examples showing charge transport following phase coherent tunneling to incoherent charge hopping across redox active molecular bridges are shown. In the case of bipyridinium (or viologen) molecular wires, it is shown how electrochemical reduction leads to an increase of the single molecule conductance, which is controlled by the liquid electrochemical

  19. ORBXYZ: a 3D single-particle orbit code for following charged-particle trajectories in equilibrium magnetic fields

    International Nuclear Information System (INIS)

    Anderson, D.V.; Cohen, R.H.; Ferguson, J.R.; Johnston, B.M.; Sharp, C.B.; Willmann, P.A.

    1981-01-01

    The single particle orbit code, TIBRO, has been modified extensively to improve the interpolation methods used and to allow use of vector potential fields in the simulation of charged particle orbits on a 3D domain. A 3D cubic B-spline algorithm is used to generate spline coefficients used in the interpolation. Smooth and accurate field representations are obtained. When vector potential fields are used, the 3D cubic spline interpolation formula analytically generates the magnetic field used to push the particles. This field has del.BETA = 0 to computer roundoff. When magnetic induction is used the interpolation allows del.BETA does not equal 0, which can lead to significant nonphysical results. Presently the code assumes quadrupole symmetry, but this is not an essential feature of the code and could be easily removed for other applications. Many details pertaining to this code are given on microfiche accompanying this report

  20. Drinking-water exposure to a mixture of nitrate and low-dose atrazine metabolites and small-for-gestational age (SGA) babies: a historic cohort study.

    Science.gov (United States)

    Migeot, V; Albouy-Llaty, M; Carles, C; Limousi, F; Strezlec, S; Dupuis, A; Rabouan, S

    2013-04-01

    Groundwater, surface water and drinking water are contaminated by nitrates and atrazine, an herbicide. They are present as a mixture in drinking water and with their endocrine-disrupting activity, they may alter fetal growth. To study an association between drinking-water atrazine metabolites/nitrate mixture exposure and small-for-gestational-age(SGA). A historic cohort study based on birth records and drinking-water nitrate and pesticide measurements in Deux-Sèvres (France) between 2005 and 2009 was carried out. Exposure to drinking-water atrazine metabolites/nitrate mixture was divided into 6 classes according to the presence or absence of atrazine metabolites and to terciles of nitrate concentrations in each trimester of pregnancy. Regression analysis of SGA by mixture exposure at second trimester was subsequently conducted. We included 11,446 woman-neonate couples of whom 37.0% were exposed to pesticides, while 99.9% of the women were exposed to nitrates. Average nitrate concentration was from 0 to 63.30 mg/L. In the second trimester of pregnancy, the risk of SGA was different with mixture exposure when drinking-water atrazine metabolites, mainly 2 hydroxyatrazine and desethylatrazine, were present and nitrate dose exposure increased: compared to single first tercile of nitrate concentration exposure, single second tercile exposure OR was 1.74 CI 95% [1.10; 2.75] and atrazine metabolites presence in the third tercile of nitrate concentration exposure OR was 0.87 CI 95% [0.45;1.67]. It is possible that the association found at the second trimester of exposure with regard to birth weight may likewise be observed before birth, with regard to the estimated fetal weight, and that it might change in the event that the atrazine metabolites dose were higher or the nitrate dose lower. It would appear necessary to further explore the variability of effects. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  1. Ion beam induced charge and cathodoluminescence imaging of response uniformity of CVD diamond radiation detectors

    CERN Document Server

    Sellin, P J; Galbiati, A; Maghrabi, M; Townsend, P D

    2002-01-01

    The uniformity of response of CVD diamond radiation detectors produced from high quality diamond film, with crystallite dimensions of >100 mu m, has been studied using ion beam induced charge imaging. A micron-resolution scanning alpha particle beam was used to produce maps of pulse height response across the device. The detectors were fabricated with a single-sided coplanar electrode geometry to maximise their sensitivity to the surface region of the diamond film where the diamond crystallites are highly ordered. High resolution ion beam induced charge images of single crystallites were acquired that demonstrate variations in intra-crystallite charge transport and the termination of charge transport at the crystallite boundaries. Cathodoluminescence imaging of the same crystallites shows an inverse correlation between the density of radiative centres and regions of good charge transport.

  2. Biochemical and secondary metabolites changes under moisture ...

    African Journals Online (AJOL)

    The study showed the importance of carbohydrate and nitrogen cycle related metabolites in mediating tolerance in cassava by affecting their phenotypic expression in the plant. Keywords: Hydrothermal stress, bio-chemicals, pigments, secondary metabolites, cassava. African Journal of Biotechnology, Vol 13(31) 3173-3186 ...

  3. MALDI Mass Spectrometry Imaging for Visualizing In Situ Metabolism of Endogenous Metabolites and Dietary Phytochemicals

    Science.gov (United States)

    Fujimura, Yoshinori; Miura, Daisuke

    2014-01-01

    Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Mass spectrometry imaging (MSI) enables determination of the distribution of ionizable molecules present in tissue sections of whole-body or single heterogeneous organ samples by direct ionization and detection. This emerging technique is now widely used for in situ label-free molecular imaging of endogenous or exogenous small molecules. MSI allows the simultaneous visualization of many types of molecules including a parent molecule and its metabolites. Thus, MSI has received much attention as a potential tool for pathological analysis, understanding pharmaceutical mechanisms, and biomarker discovery. On the other hand, several issues regarding the technical limitations of MSI are as of yet still unresolved. In this review, we describe the capabilities of the latest matrix-assisted laser desorption/ionization (MALDI)-MSI technology for visualizing in situ metabolism of endogenous metabolites or dietary phytochemicals (food factors), and also discuss the technical problems and new challenges, including MALDI matrix selection and metabolite identification, that need to be addressed for effective and widespread application of MSI in the diverse fields of biological, biomedical, and nutraceutical (food functionality) research. PMID:24957029

  4. Prospective study of blood metabolites associated with colorectal cancer risk.

    Science.gov (United States)

    Shu, Xiang; Xiang, Yong-Bing; Rothman, Nathaniel; Yu, Danxia; Li, Hong-Lan; Yang, Gong; Cai, Hui; Ma, Xiao; Lan, Qing; Gao, Yu-Tang; Jia, Wei; Shu, Xiao-Ou; Zheng, Wei

    2018-02-26

    Few prospective studies, and none in Asians, have systematically evaluated the relationship between blood metabolites and colorectal cancer risk. We conducted a nested case-control study to search for risk-associated metabolite biomarkers for colorectal cancer in an Asian population using blood samples collected prior to cancer diagnosis. Conditional logistic regression was performed to assess associations of metabolites with cancer risk. In this study, we included 250 incident cases with colorectal cancer and individually matched controls nested within two prospective Shanghai cohorts. We found 35 metabolites associated with risk of colorectal cancer after adjusting for multiple comparisons. Among them, 12 metabolites were glycerophospholipids including nine associated with reduced risk of colorectal cancer and three with increased risk [odds ratios per standard deviation increase of transformed metabolites: 0.31-1.98; p values: 0.002-1.25 × 10 -10 ]. The other 23 metabolites associated with colorectal cancer risk included nine lipids other than glycerophospholipid, seven aromatic compounds, five organic acids and four other organic compounds. After mutual adjustment, nine metabolites remained statistically significant for colorectal cancer. Together, these independently associated metabolites can separate cancer cases from controls with an area under the curve of 0.76 for colorectal cancer. We have identified that dysregulation of glycerophospholipids may contribute to risk of colorectal cancer. © 2018 UICC.

  5. Probing nuclear correlations with pion-nucleus double charge exchange

    International Nuclear Information System (INIS)

    Ginocchio, J.N.

    1988-01-01

    In this paper we have calculated the lowest order pion double charge reaction mechanism using shell model wavefunctions of medium weight nuclei. We have the sequential reaction mechanism in which the pion undergoes two single-charge exchange scatterings on the valence neutrons. The distortion of the incoming, intermediate, and outgoing pion are included. The closure approximation is made for the intermediate states with an average excitation energy used in the pion propagator. The double-charge exchange is assumed to take place on the valence nucleons which are assumed to be in one spherical shell model orbital. 34 refs., 5 figs., 3 tabs

  6. Detection of fenspiride and identification of in vivo metabolites in horse body fluids by capillary gas chromatography-mass spectrometry: administration, biotransformation and urinary excretion after a single oral dose.

    Science.gov (United States)

    Dumasia, M C; Houghton, E; Hyde, W; Greulich, D; Nelson, T; Peterson, Jackie

    2002-02-05

    Studies related to the in vivo biotransforrmation and urinary excretion of fenspiride hydrochloride in the horse are described. After oral administration, the drug is metabolised by both phase I functionalisation and phase II conjugation pathways. Following enzymatic deconjugation, fenspiride and its phase I metabolites were isolated from post-administration biofluids using bonded co-polymeric mixed mode solid-phase extraction cartridges to isolate the basic compounds. Following trimethylsilylation (TMS), the parent drug and metabolites were identified by capillary gas chromatography-mass spectrometry (GC-MS). Fenspiride (A) and seven metabolites (B-->G) arising from oxidation on both the aromatic and heterocyclic substructures were detected in urine. The positive ion electron ionisation mass spectra of the TMS derivatives of fenspiride and its metabolites provided useful information on its metabolism. Positive ion methane chemical ionisation-GC-MS of the derivatives provided both derivatised molecular mass and structural information. Unchanged fenspiride can be detected in post-administration plasma and urine samples for up to 24 h. Maximum urinary levels of 100-200 ng ml(-1) were observed between 3 and 5 h after administration. After enzymatic deconjugation, the major phenolic metabolite (G) can be detected in urine for up to 72 h. This metabolite is the analyte of choice in the GC-MS screening of post-race equine urine samples for detection of fenspiride use. However, a distinct difference was observed in the urinary excretion of this metabolite between the thoroughbred horses used in UK study and the quarterbred and standardbred horses used for the USA administrations.

  7. Placental vitamin D metabolism and its associations with circulating vitamin D metabolites in pregnant women.

    Science.gov (United States)

    Park, Heyjun; Wood, Madeleine R; Malysheva, Olga V; Jones, Sara; Mehta, Saurabh; Brannon, Patsy M; Caudill, Marie A

    2017-12-01

    Background: Little is known about placental vitamin D metabolism and its impact on maternal circulating vitamin D concentrations in humans. Objective: This study sought to advance the current understanding of placental vitamin D metabolism and its role in modulating maternal circulating vitamin D metabolites during pregnancy. Design: Nested within a feeding study, 24 healthy pregnant women (26-29 wk of gestation) consumed a single amount of vitamin D (511 IU/d from diet and a cholecalciferol supplement) for 10 wk. Concentrations of placental and blood vitamin D metabolites and placental messenger RNA (mRNA) abundance of vitamin D metabolic pathway components were quantified. In addition, cultured human trophoblasts were incubated with 13 C-cholecalciferol to examine the intracellular generation and secretion of vitamin D metabolites along with the regulation of target genes. Results: In placental tissue, 25-hydroxyvitamin D 3 [25(OH)D 3 ] was strongly correlated ( r = 0.83, P D 3 Moreover, these placental metabolites were strongly correlated ( r ≤ 0.85, P ≤ 0.04) with their respective metabolites in maternal circulation. Positive associations ( P ≤ 0.045) were also observed between placental mRNA abundance of vitamin D metabolic components and circulating vitamin D metabolites [i.e., LDL-related protein 2 ( LRP2 , also known as megalin) with 25(OH)D 3 and the C3 epimer of 25(OH)D 3 [3-epi-25(OH)D 3 ]; cubilin ( CUBN ) with 25(OH)D 3 ; 25-hydroxylase ( CYP2R1 ) with 3-epi-25(OH)D 3 ; 24-hydroxylase ( CYP24A1 ) with 25(OH)D 3 , 3-epi-25(OH)D 3 , and 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ]; and 1α-hydroxylase [( CYP27B1 ) with 3-epi-25(OH)D 3 and 1,25(OH) 2 D 3 ]. Notably, in vitro experiments with trophoblasts showed increased production and secretion of 25(OH)D 3 and higher CYP24A1 gene transcript abundance in response to cholecalciferol treatment. Conclusions: The numerous associations of many of the placental biomarkers of vitamin D metabolism with

  8. Plasmons in inhomogeneously doped neutral and charged graphene nanodisks

    Energy Technology Data Exchange (ETDEWEB)

    Silveiro, Iván [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Javier García de Abajo, F., E-mail: javier.garciadeabajo@icfo.es [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys, 23, 08010 Barcelona (Spain)

    2014-03-31

    We study plasmons in graphene nanodisks including the effect of inhomogeneity in the distribution of the doping charge. Specifically, we discuss the following two configurations: charged disks containing a fixed amount of additional carriers, which are self-consistently distributed along the surface to produce a uniform DC potential; and neutral disks exposed to a neighboring external point charge. A suitable finite-element method is elaborated to compute the charge density associated with the plasmons in the electrostatic limit. For charged disks, we find dipolar plasmons similar to those of uniformly doped graphene structures, in which the plasmon induced charge piles up near the edges. In contrast, in neutral disks placed near an external point charge, plasmons are strongly localized away from the edges. Surprisingly, a single external electron is enough to trap plasmons. The disks also display axially symmetric dark-plasmons, which can be excited through external illumination by coupling them to a neighboring metallic element. Our results have practical relevance for graphene nanophotonics under inhomogeneous doping conditions.

  9. Charging equipment for several batteries. Ladegeraet fuer mehrere Akkumulatoren

    Energy Technology Data Exchange (ETDEWEB)

    Unruh, H

    1980-11-27

    The charging equipment for several batteries according to the invention, each of which is connected in series with a transistor controlling the charging current and where the battery voltage is divided by a voltage divider and taken to a controller, which controls the series transistor, is characterised by the fact that all the batteries are connected to a circuit to form the mean value of the battery voltages, which consists of a resistance star circuit, whose star point is connected to the voltage divider and whose end points are connected to the batteries, and that all the series transistors are connected to a common controller, which is controlled by the pick-off voltage of the voltage divider. In the charging equipment of the invention, the series transistors of all batteries are controlled synchronously by a single controller. If the batteries are in different states of charge, then the charging currents will be distributed differently according to their inside resistances, so that the battery with the lowest state of charge will receive the highest charging current.

  10. MARSI: metabolite analogues for rational strain improvement

    DEFF Research Database (Denmark)

    Cardoso, João G. R.; Zeidan, Ahmad A; Jensen, Kristian

    2018-01-01

    reactions in an organism can be used to predict effects of MAs on cellular phenotypes. Here, we present the Metabolite Analogues for Rational Strain Improvement (MARSI) framework. MARSI provides a rational approach to strain improvement by searching for metabolites as targets instead of genes or reactions...

  11. Charged particle layers in the Debye limit.

    Science.gov (United States)

    Golden, Kenneth I; Kalman, Gabor J; Kyrkos, Stamatios

    2002-09-01

    We develop an equivalent of the Debye-Hückel weakly coupled equilibrium theory for layered classical charged particle systems composed of one single charged species. We consider the two most important configurations, the charged particle bilayer and the infinite superlattice. The approach is based on the link provided by the classical fluctuation-dissipation theorem between the random-phase approximation response functions and the Debye equilibrium pair correlation function. Layer-layer pair correlation functions, screened and polarization potentials, static structure functions, and static response functions are calculated. The importance of the perfect screening and compressibility sum rules in determining the overall behavior of the system, especially in the r--> infinity limit, is emphasized. The similarities and differences between the quasi-two-dimensional bilayer and the quasi-three-dimensional superlattice are highlighted. An unexpected behavior that emerges from the analysis is that the screened potential, the correlations, and the screening charges carried by the individual layers exhibit a marked nonmonotonic dependence on the layer separation.

  12. Charged particle layers in the Debye limit

    International Nuclear Information System (INIS)

    Golden, Kenneth I.; Kalman, Gabor J.; Kyrkos, Stamatios

    2002-01-01

    We develop an equivalent of the Debye-Hueckel weakly coupled equilibrium theory for layered classical charged particle systems composed of one single charged species. We consider the two most important configurations, the charged particle bilayer and the infinite superlattice. The approach is based on the link provided by the classical fluctuation-dissipation theorem between the random-phase approximation response functions and the Debye equilibrium pair correlation function. Layer-layer pair correlation functions, screened and polarization potentials, static structure functions, and static response functions are calculated. The importance of the perfect screening and compressibility sum rules in determining the overall behavior of the system, especially in the r→∞ limit, is emphasized. The similarities and differences between the quasi-two-dimensional bilayer and the quasi-three-dimensional superlattice are highlighted. An unexpected behavior that emerges from the analysis is that the screened potential, the correlations, and the screening charges carried by the individual layers exhibit a marked nonmonotonic dependence on the layer separation

  13. Charged track multiplicity in B meson decay

    International Nuclear Information System (INIS)

    Brandenburg, G.; Ershov, A.; Gao, Y. S.; Kim, D. Y.-J.; Wilson, R.; Browder, T. E.; Li, Y.; Rodriguez, J. L.; Yamamoto, H.; Bergfeld, T.

    2000-01-01

    We have used the CLEO II detector to study the multiplicity of charged particles in the decays of B mesons produced at the Υ(4S) resonance. Using a sample of 1.5x10 6 B meson pairs, we find the mean inclusive charged particle multiplicity to be 10.71±0.02 -0.15 +0.21 for the decay of the pair. This corresponds to a mean multiplicity of 5.36±0.01 -0.08 +0.11 for a single B meson. Using the same data sample, we have also extracted the mean multiplicities in semileptonic and nonleptonic decays. We measure a mean of 7.82±0.05 -0.19 +0.21 charged particles per BB(bar sign) decay when both mesons decay semileptonically. When neither B meson decays semileptonically, we measure a mean charged particle multiplicity of 11.62±0.04 -0.18 +0.24 per BB(bar sign) pair. (c) 2000 The American Physical Society

  14. Production of fungal and bacterial growth modulating secondary metabolites is widespread among mycorrhiza-associated streptomycetes

    Directory of Open Access Journals (Sweden)

    Schrey Silvia D

    2012-08-01

    Full Text Available Abstract Background Studies on mycorrhiza associated bacteria suggest that bacterial-fungal interactions play important roles during mycorrhiza formation and affect plant health. We surveyed Streptomyces Actinobacteria, known as antibiotic producers and antagonists of fungi, from Norway spruce mycorrhizas with predominantly Piloderma species as the fungal partner. Results Fifteen Streptomyces isolates exhibited substantial variation in inhibition of tested mycorrhizal and plant pathogenic fungi (Amanita muscaria, Fusarium oxysporum, Hebeloma cylindrosporum, Heterobasidion abietinum, Heterobasidion annosum, Laccaria bicolor, Piloderma croceum. The growth of the mycorrhiza-forming fungus Laccaria bicolor was stimulated by some of the streptomycetes, and Piloderma croceum was only moderately affected. Bacteria responded to the streptomycetes differently than the fungi. For instance the strain Streptomyces sp. AcM11, which inhibited most tested fungi, was less inhibitory to bacteria than other tested streptomycetes. The determined patterns of Streptomyces-microbe interactions were associated with distinct patterns of secondary metabolite production. Notably, potentially novel metabolites were produced by strains that were less antagonistic to fungi. Most of the identified metabolites were antibiotics (e.g. cycloheximide, actiphenol and siderophores (e.g. ferulic acid, desferroxiamines. Plant disease resistance was activated by a single streptomycete strain only. Conclusions Mycorrhiza associated streptomycetes appear to have an important role in inhibiting the growth of fungi and bacteria. Additionally, our study indicates that the Streptomyces strains, which are not general antagonists of fungi, may produce still un-described metabolites.

  15. Dynamical interaction of He atoms with metal surfaces: Charge transfer processes

    International Nuclear Information System (INIS)

    Flores, F.; Garcia Vidal, F.J.; Monreal, R.

    1993-01-01

    A self-consistent Kohn-Sham LCAO method is presented to calculate the charge transfer processes between a He * -atom and metal surfaces. Intra-atomic correlation effects are taken into account by considering independently each single He-orbital and by combining the different charge transfer processes into a set of dynamical rate equations for the different ion charge fractions. Our discussion reproduces qualitatively the experimental evidence and gives strong support to the method presented here. (author). 24 refs, 4 figs

  16. Metabolite identification through multiple kernel learning on fragmentation trees.

    Science.gov (United States)

    Shen, Huibin; Dührkop, Kai; Böcker, Sebastian; Rousu, Juho

    2014-06-15

    Metabolite identification from tandem mass spectrometric data is a key task in metabolomics. Various computational methods have been proposed for the identification of metabolites from tandem mass spectra. Fragmentation tree methods explore the space of possible ways in which the metabolite can fragment, and base the metabolite identification on scoring of these fragmentation trees. Machine learning methods have been used to map mass spectra to molecular fingerprints; predicted fingerprints, in turn, can be used to score candidate molecular structures. Here, we combine fragmentation tree computations with kernel-based machine learning to predict molecular fingerprints and identify molecular structures. We introduce a family of kernels capturing the similarity of fragmentation trees, and combine these kernels using recently proposed multiple kernel learning approaches. Experiments on two large reference datasets show that the new methods significantly improve molecular fingerprint prediction accuracy. These improvements result in better metabolite identification, doubling the number of metabolites ranked at the top position of the candidates list. © The Author 2014. Published by Oxford University Press.

  17. Electrostatic solvation free energies of charged hard spheres using molecular dynamics with density functional theory interactions

    Science.gov (United States)

    Duignan, Timothy T.; Baer, Marcel D.; Schenter, Gregory K.; Mundy, Chistopher J.

    2017-10-01

    Determining the solvation free energies of single ions in water is one of the most fundamental problems in physical chemistry and yet many unresolved questions remain. In particular, the ability to decompose the solvation free energy into simple and intuitive contributions will have important implications for models of electrolyte solution. Here, we provide definitions of the various types of single ion solvation free energies based on different simulation protocols. We calculate solvation free energies of charged hard spheres using density functional theory interaction potentials with molecular dynamics simulation and isolate the effects of charge and cavitation, comparing to the Born (linear response) model. We show that using uncorrected Ewald summation leads to unphysical values for the single ion solvation free energy and that charging free energies for cations are approximately linear as a function of charge but that there is a small non-linearity for small anions. The charge hydration asymmetry for hard spheres, determined with quantum mechanics, is much larger than for the analogous real ions. This suggests that real ions, particularly anions, are significantly more complex than simple charged hard spheres, a commonly employed representation.

  18. Metabolite-cycled STEAM and semi-LASER localization for MR spectroscopy of the human brain at 9.4T.

    Science.gov (United States)

    Giapitzakis, Ioannis-Angelos; Shao, Tingting; Avdievich, Nikolai; Mekle, Ralf; Kreis, Roland; Henning, Anke

    2018-04-01

    Metabolite cycling (MC) is an MRS technique for the simultaneous acquisition of water and metabolite spectra that avoids chemical exchange saturation transfer effects and for which water may serve as a reference signal or contain additional information in functional or diffusion studies. Here, MC was developed for human investigations at ultrahigh field. MC-STEAM and MC-semi-LASER are introduced at 9.4T with an optimized inversion pulse and elaborate coil setup. Experimental and simulation results are given for the implementation of adiabatic inversion pulses for MC. The two techniques are compared, and the effect of frequency and phase correction based on the MC water spectra is evaluated. Finally, absolute quantification of metabolites is performed. The proposed coil configuration results in a maximum B1 + of 48 μΤ in a voxel within the occipital lobe. Frequency and phase correction of single acquisitions improve signal-to-noise ratio (SNR) and linewidth, leading to high-resolution spectra. The improvement of SNR of N-acetylaspartate (SNR NAA ) for frequency aligned data, acquired with MC-STEAM and MC-semi-LASER, are 37% and 30%, respectively (P < 0.05). Moreover, a doubling of the SNR NAA for MC-semi-LASER in comparison with MC-STEAM is observed (P < 0.05). Concentration levels for 18 metabolites from the human occipital lobe are reported, as acquired with both MC-STEAM and MC-semi-LASER. This work introduces a novel methodology for single-voxel MRS on a 9.4T whole-body scanner and highlights the advantages of semi-LASER compared to STEAM in terms of excitation profile. In comparison with MC-STEAM, MC-semi-LASER yields spectra with higher SNR. Magn Reson Med 79:1841-1850, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  19. Engineering of secondary metabolite production in streptomycetes

    DEFF Research Database (Denmark)

    Robertsen, Helene Lunde; Gram, Lone

    Streptomycetes are known for their ability to produce a range of different secondary metabolites, including antibiotics, immunosuppressive, anti-fungals, and anti-cancer compounds. Of these compounds, antibiotics play an important role in the clinics for treatment of both mild and severe bacterial...... the computational prediction of suitable 20 bp protospacers for the single guide RNAs and a USER-cloning method for construction of the CRISPR plasmids. Additional improvement to the system was achieved through the development of an optimised USER assembly workflow for cheaper and faster plasmid construction....... The workflow was verified by manual knock-down of two biosynthetic gene clusters in model organism Streptomyces coelicolor A3(2), which confirmed the applicability of the system. A second part of the thesis was devoted to engineering of Streptomyces collinus Tü 365, which is a known producer of the narrow...

  20. Do metabolites that are produced during resistance exercise enhance muscle hypertrophy?

    Science.gov (United States)

    Dankel, Scott J; Mattocks, Kevin T; Jessee, Matthew B; Buckner, Samuel L; Mouser, J Grant; Loenneke, Jeremy P

    2017-11-01

    Many reviews conclude that metabolites play an important role with respect to muscle hypertrophy during resistance exercise, but their actual physiologic contribution remains unknown. Some have suggested that metabolites may work independently of muscle contraction, while others have suggested that metabolites may play a secondary role in their ability to augment muscle activation via inducing fatigue. Interestingly, the studies used as support for an anabolic role of metabolites use protocols that are not actually designed to test the importance of metabolites independent of muscle contraction. While there is some evidence in vitro that metabolites may induce muscle hypertrophy, the only study attempting to answer this question in humans found no added benefit of pooling metabolites within the muscle post-exercise. As load-induced muscle hypertrophy is thought to work via mechanotransduction (as opposed to being metabolically driven), it seems likely that metabolites simply augment muscle activation and cause the mechanotransduction cascade in a larger proportion of muscle fibers, thereby producing greater muscle growth. A sufficient time under tension also appears necessary, as measurable muscle growth is not observed after repeated maximal testing. Based on current evidence, it is our opinion that metabolites produced during resistance exercise do not have anabolic properties per se, but may be anabolic in their ability to augment muscle activation. Future studies are needed to compare protocols which produce similar levels of muscle activation, but differ in the magnitude of metabolites produced, or duration in which the exercised muscles are exposed to metabolites.

  1. Room-temperature current blockade in atomically defined single-cluster junctions

    Science.gov (United States)

    Lovat, Giacomo; Choi, Bonnie; Paley, Daniel W.; Steigerwald, Michael L.; Venkataraman, Latha; Roy, Xavier

    2017-11-01

    Fabricating nanoscopic devices capable of manipulating and processing single units of charge is an essential step towards creating functional devices where quantum effects dominate transport characteristics. The archetypal single-electron transistor comprises a small conducting or semiconducting island separated from two metallic reservoirs by insulating barriers. By enabling the transfer of a well-defined number of charge carriers between the island and the reservoirs, such a device may enable discrete single-electron operations. Here, we describe a single-molecule junction comprising a redox-active, atomically precise cobalt chalcogenide cluster wired between two nanoscopic electrodes. We observe current blockade at room temperature in thousands of single-cluster junctions. Below a threshold voltage, charge transfer across the junction is suppressed. The device is turned on when the temporary occupation of the core states by a transiting carrier is energetically enabled, resulting in a sequential tunnelling process and an increase in current by a factor of ∼600. We perform in situ and ex situ cyclic voltammetry as well as density functional theory calculations to unveil a two-step process mediated by an orbital localized on the core of the cluster in which charge carriers reside before tunnelling to the collector reservoir. As the bias window of the junction is opened wide enough to include one of the cluster frontier orbitals, the current blockade is lifted and charge carriers can tunnel sequentially across the junction.

  2. Concentrations of isoflavones and their metabolites in the blood of pregnant and non-pregnant heifers fed soy bean.

    Science.gov (United States)

    Woclawek-Potocka, Izabela; Piskula, Mariusz Krzysztof; Bah, Mamadou; Siemieniuch, Marta Jolanta; Korzekwa, Anna; Brzezicka, Edyta; Skarzynski, Dariusz Jan

    2008-10-01

    The present study compared the changes in isoflavones (daidzein and genistein) and their metabolite (equol and para-ethyl-phenol) concentrations in the blood plasma of cyclic and pregnant heifers after feeding with soy bean. Twelve healthy heifers were divided into three groups: cyclic heifers (days 8-12 of the estrous cycle; control group; n=4), an early pregnancy group (2 months pregnant; n=4) and a late pregnancy group (8 months pregnant; n=4). All heifers were fed a single dose of 2.5 kg of soy bean and then blood samples were taken from the jugular vein for 8 h at predetermined intervals. The concentrations of soy bean-derived isoflavones and their active metabolites were measured in the blood plasma on an HPLC system. In the blood plasma of the early- and late-pregnant heifers, we found lower concentrations and time-dependent decreases in daidzein and genistein in comparison to cyclic heifers (P0.05). In conclusion, physiological status (cyclicity or pregnancy) of the females influenced the concentrations of isoflavone metabolites in the blood plasma of the heifers. The stage of pregnancy affects isoflavone absorption, biotransformation and metabolism differently and results in higher concentrations of active metabolites of isoflavones during early pregnancy in comparison to their lower concentrations during late pregnancy. Therefore, we surmise that cows are more sensitive to active isoflavone metabolite actions during early pregnancy than cyclic heifers and heifers in late pregnancy.

  3. Spectroscopy of Charged Quantum Dot Molecules

    Science.gov (United States)

    Stinaff, E. A.; Scheibner, M.; Bracker, A. S.; Ponomarev, I. V.; Ware, M. E.; Doty, M. F.; Reinecke, T. L.; Gammon, D.; Korenev, V. L.

    2006-03-01

    Spins of single charges in quantum dots are attractive for many quantum information and spintronic proposals. Scalable quantum information applications require the ability to entangle and operate on multiple spins in coupled quantum dots (CQDs). To further the understanding of these systems, we present detailed spectroscopic studies of InAs CQDs with control of the discrete electron or hole charging of the system. The optical spectrum reveals a pattern of energy anticrossings and crossings in the photoluminescence as a function of applied electric field. These features can be understood as a superposition of charge and spin configurations of the two dots and represent clear signatures of quantum mechanical coupling. The molecular resonance leading to these anticrossings is achieved at different electric fields for the optically excited (trion) states and the ground (hole) states allowing for the possibility of using the excited states for optically induced coupling of the qubits.

  4. ABC's of pion charge exchange

    International Nuclear Information System (INIS)

    Gibbs, W.R.; Kaufmann, W.B.; Siegel, P.B.

    1985-01-01

    Calculations of pion single charge exchange using the PWIA and DWIA are presented. Emphasis is given to the effects of absorbtion and blocking. A microscopic calculation of the 0 0 excitation and low energy angular distribution is in excellent agreement with the data. A fixed nucleon multiple scattering calculation of the pion double charge exchange reaction is presented. Various valence neutron wave functions are used, and the contributions of different spatial orientations of the last two neutrons to the reaction are examined. The DCX cross section is found to be very sensitive to the inclusion of correlations in the two-neutron wave function. Satisfactory agreement with DCX data on 14 C can be obtained using a nucleonic picture of the nucleus

  5. Methodological considerations for measuring glucocorticoid metabolites in feathers

    Science.gov (United States)

    Berk, Sara A.; McGettrick, Julie R.; Hansen, Warren K.; Breuner, Creagh W.

    2016-01-01

    In recent years, researchers have begun to use corticosteroid metabolites in feathers (fCORT) as a metric of stress physiology in birds. However, there remain substantial questions about how to measure fCORT most accurately. Notably, small samples contain artificially high amounts of fCORT per millimetre of feather (the small sample artefact). Furthermore, it appears that fCORT is correlated with circulating plasma corticosterone only when levels are artificially elevated by the use of corticosterone implants. Here, we used several approaches to address current methodological issues with the measurement of fCORT. First, we verified that the small sample artefact exists across species and feather types. Second, we attempted to correct for this effect by increasing the amount of methanol relative to the amount of feather during extraction. We consistently detected more fCORT per millimetre or per milligram of feather in small samples than in large samples even when we adjusted methanol:feather concentrations. We also used high-performance liquid chromatography to identify hormone metabolites present in feathers and measured the reactivity of these metabolites against the most commonly used antibody for measuring fCORT. We verified that our antibody is mainly identifying corticosterone (CORT) in feathers, but other metabolites have significant cross-reactivity. Lastly, we measured faecal glucocorticoid metabolites in house sparrows and correlated these measurements with corticosteroid metabolites deposited in concurrently grown feathers; we found no correlation between faecal glucocorticoid metabolites and fCORT. We suggest that researchers should be cautious in their interpretation of fCORT in wild birds and should seek alternative validation methods to examine species-specific relationships between environmental challenges and fCORT. PMID:27335650

  6. Selective Coherent Excitation of Charged Density Waves

    NARCIS (Netherlands)

    Tsvetkov, A.A.; Sagar, D.M.; Loosdrecht, P.H.M. van; Marel, D. van der

    2003-01-01

    Real time femtosecond pump-probe spectroscopy is used to study collective and single particle excitations in the charge density wave state of the quasi-1D metal, blue bronze. Along with the previously observed collective amplitudon excitation, the spectra show several additional coherent features.

  7. Accurate Charge Densities from Powder Diffraction

    DEFF Research Database (Denmark)

    Bindzus, Niels; Wahlberg, Nanna; Becker, Jacob

    Synchrotron powder X-ray diffraction has in recent years advanced to a level, where it has become realistic to probe extremely subtle electronic features. Compared to single-crystal diffraction, it may be superior for simple, high-symmetry crystals owing to negligible extinction effects and minimal...... peak overlap. Additionally, it offers the opportunity for collecting data on a single scale. For charge densities studies, the critical task is to recover accurate and bias-free structure factors from the diffraction pattern. This is the focal point of the present study, scrutinizing the performance...

  8. Secondary Metabolites from Higher Fungi: Discovery, Bioactivity, and Bioproduction

    Science.gov (United States)

    Zhong, Jian-Jiang; Xiao, Jian-Hui

    Medicinal higher fungi such as Cordyceps sinensis and Ganoderma lucidum have been used as an alternative medicine remedy to promote health and longevity for people in China and other regions of the world since ancient times. Nowadays there is an increasing public interest in the secondary metabolites of those higher fungi for discovering new drugs or lead compounds. Current research in drug discovery from medicinal higher fungi involves a multifaceted approach combining mycological, biochemical, pharmacological, metabolic, biosynthetic and molecular techniques. In recent years, many new secondary metabolites from higher fungi have been isolated and are more likely to provide lead compounds for new drug discovery, which may include chemopreventive agents possessing the bioactivity of immunomodulatory, anticancer, etc. However, numerous challenges of secondary metabolites from higher fungi are encountered including bioseparation, identification, biosynthetic metabolism, and screening model issues, etc. Commercial production of secondary metabolites from medicinal mushrooms is still limited mainly due to less information about secondary metabolism and its regulation. Strategies for enhancing secondary metabolite production by medicinal mushroom fermentation include two-stage cultivation combining liquid fermentation and static culture, two-stage dissolved oxygen control, etc. Purification of bioactive secondary metabolites, such as ganoderic acids from G. lucidum, is also very important to pharmacological study and future pharmaceutical application. This review outlines typical examples of the discovery, bioactivity, and bioproduction of secondary metabolites of higher fungi origin.

  9. Microscopic origin of the charge transfer in single crystals based on thiophene derivatives: A combined NEXAFS and density functional theory approach

    Energy Technology Data Exchange (ETDEWEB)

    Chernenkaya, A., E-mail: chernenk@uni-mainz.de [Graduate School Materials Science in Mainz, 55128 Mainz (Germany); Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Morherr, A.; Witt, S.; Krellner, C. [Physikalisches Institut, Goethe-Universität, 60438 Frankfurt am Main (Germany); Backes, S.; Popp, W.; Jeschke, H. O.; Valentí, R. [Institut für Theoretische Physik, Goethe-Universität, 60438 Frankfurt am Main (Germany); Kozina, X.; Nepijko, S. A.; Elmers, H. J.; Schönhense, G. [Institut für Physik, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Bolte, M. [Institut für Anorganische Chemie, Goethe-Universität, 60438 Frankfurt am Main (Germany); Medjanik, K.; Öhrwall, G. [MAX-IV Laboratory, Lund University, 22100 Lund (Sweden); Baumgarten, M. [Max-Planck-Institut für Polymerforschung, 55021 Mainz (Germany)

    2016-07-21

    We have investigated the charge transfer mechanism in single crystals of DTBDT-TCNQ and DTBDT-F{sub 4}TCNQ (where DTBDT is dithieno[2,3-d;2′,3′-d′] benzo[1,2-b;4,5-b′]dithiophene) using a combination of near-edge X-ray absorption spectroscopy (NEXAFS) and density functional theory calculations (DFT) including final state effects beyond the sudden state approximation. In particular, we find that a description that considers the partial screening of the electron-hole Coulomb correlation on a static level as well as the rearrangement of electronic density shows excellent agreement with experiment and allows to uncover the details of the charge transfer mechanism in DTBDT-TCNQ and DTBDT-F{sub 4} TCNQ, as well as a reinterpretation of previous NEXAFS data on pure TCNQ. Finally, we further show that almost the same quality of agreement between theoretical results and experiment is obtained by the much faster Z+1/2 approximation, where the core hole effects are simulated by replacing N or F with atomic number Z with the neighboring atom with atomic number Z+1/2.

  10. Exclusion of exotic top-like quarks with -4/3 electric charge using jet-charge tagging in single-lepton ttbar events at CDF

    CERN Document Server

    Aaltonen, T.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K.R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H.S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y.C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M.A.; Clark, A.; Clarke, C.; Convery, M.E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C.A.; Cox, D.J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; d'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J.R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernandez Ramos, J.P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J.C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A.F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C.M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzalez Lopez, O.; Gorelov, I.; Goshaw, A.T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R.C.; Guimaraes da Costa, J.; Hahn, S.R.; Han, J.Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R.F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R.E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E.J.; Jindariani, S.; Jones, M.; Joo, K.K.; Jun, S.Y.; Junk, T.R.; Kambeitz, M.; Kamon, T.; Karchin, P.E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D.H.; Kim, H.S.; Kim, J.E.; Kim, M.J.; Kim, S.B.; Kim, S.H.; Kim, Y.J.; Kim, Y.K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D.J.; Konigsberg, J.; Kotwal, A.V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A.T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H.S.; Lee, J.S.; Leo, S.; Leone, S.; Lewis, J.D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Luca, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martinez, M.; Matera, K.; Mattson, M.E.; Mazzacane, A.; Mazzanti, P.; McFarland, K.S.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C.S.; Moore, R.; Morello, M.J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S.Y.; Norniella, O.; Oakes, L.; Oh, S.H.; Oh, Y.D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T.J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernandez, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J.L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W.K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E.E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S.Z.; Shears, T.; Shepard, P.F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J.R.; Snider, F.D.; Song, H.; Sorin, V.; Stancari, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P.K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vazquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizan, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S.M.; Warburton, A.; Waters, D.; Wester, W.C., III; Whiteson, D.; Wicklund, A.B.; Wilbur, S.; Williams, H.H.; Wilson, J.S.; Wilson, P.; Winer, B.L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U.K.; Yang, Y.C.; Yao, W.M.; Yeh, G.P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G.B.; Yu, I.; Zanetti, A.M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2013-08-05

    We report on a measurement of the top-quark electric charge in ttbar events in which one W boson originating from the top-quark pair decays into leptons and the other into hadrons. The event sample was collected by the CDF II detector in sqrt(s)=1.96 TeV proton-antiproton collisions and corresponds to 5.6 fb^(-1). We find the data to be consistent with the standard model and exclude the existence of an exotic quark with -4/3 electric charge and mass of the conventional top quark at the 99% confidence level.

  11. Neurochemical metabolites in prefrontal cortex in patients with mild/moderate levels in first-episode depression

    Directory of Open Access Journals (Sweden)

    Sozeri-Varma G

    2013-08-01

    Full Text Available Gülfizar Sözeri-Varma,1 Nalan Kalkan-Oğuzhanoglu,1 Muharrem Efe,1 Yilmaz Kiroglu,2 Taçlan Duman11Department of Psychiatry, 2Department of Radiology, Faculty of Medicine, Pamukkale University, Denizli, TurkeyBackground: Previous studies have determined the neurochemical metabolite abnormalities in major depressive disorder (MDD. The results of studies are inconsistent. Severity of depression may relate to neurochemical metabolic changes. The aim of this study is to investigate neurochemical metabolite levels in the prefrontal cortex (PFC of patients with mild/moderate MDD.Methods: Twenty-one patients with mild MDD, 18 patients with moderate MDD, and 16 matched control subjects participated in the study. Patients had had their first episode. They had not taken treatment. The severity of depression was assessed by the Hamilton Rating Scale for Depression (HAM-D. Levels of N-acetyl aspartate (NAA, choline-containing compounds (Cho, and creatine-containing compounds (Cr were measured using proton magnetic resonance spectroscopy (1H-MRS at 1.5 T, with an 8-cm3 single voxel placed in the right PFC.Results: The moderate MDD patients had lower NAA/Cr levels than the control group. No differences were found in neurochemical metabolite levels between the mild MDD and control groups. No correlation was found between the patients’ neurochemical metabolite levels and HAM-D scores.Conclusion: Our findings suggest that NAA/Cr levels are low in moderate-level MDD in the PFC. Neurochemical metabolite levels did not change in mild depressive disorder. Our results suggest that the severity of depression may affect neuronal function and viability. Studies are needed to confirm this finding, including studies on severely depressive patients.Keywords: major depressive disorder, magnetic resonance spectroscopy, N-acetyl aspartate, creatine, choline

  12. Pharmaceutically active secondary metabolites of marine actinobacteria.

    Science.gov (United States)

    Manivasagan, Panchanathan; Venkatesan, Jayachandran; Sivakumar, Kannan; Kim, Se-Kwon

    2014-04-01

    Marine actinobacteria are one of the most efficient groups of secondary metabolite producers and are very important from an industrial point of view. Many representatives of the order Actinomycetales are prolific producers of thousands of biologically active secondary metabolites. Actinobacteria from terrestrial sources have been studied and screened since the 1950s, for many important antibiotics, anticancer, antitumor and immunosuppressive agents. However, frequent rediscovery of the same compounds from the terrestrial actinobacteria has made them less attractive for screening programs in the recent years. At the same time, actinobacteria isolated from the marine environment have currently received considerable attention due to the structural diversity and unique biological activities of their secondary metabolites. They are efficient producers of new secondary metabolites that show a range of biological activities including antibacterial, antifungal, anticancer, antitumor, cytotoxic, cytostatic, anti-inflammatory, anti-parasitic, anti-malaria, antiviral, antioxidant, anti-angiogenesis, etc. In this review, an evaluation is made on the current status of research on marine actinobacteria yielding pharmaceutically active secondary metabolites. Bioactive compounds from marine actinobacteria possess distinct chemical structures that may form the basis for synthesis of new drugs that could be used to combat resistant pathogens. With the increasing advancement in science and technology, there would be a greater demand for new bioactive compounds synthesized by actinobacteria from various marine sources in future. Copyright © 2013 Elsevier GmbH. All rights reserved.

  13. Metabolites in vertebrate Hedgehog signaling.

    Science.gov (United States)

    Roberg-Larsen, Hanne; Strand, Martin Frank; Krauss, Stefan; Wilson, Steven Ray

    2014-04-11

    The Hedgehog (HH) signaling pathway is critical in embryonic development, stem cell biology, tissue homeostasis, chemoattraction and synapse formation. Irregular HH signaling is associated with a number of disease conditions including congenital disorders and cancer. In particular, deregulation of HH signaling has been linked to skin, brain, lung, colon and pancreatic cancers. Key mediators of the HH signaling pathway are the 12-pass membrane protein Patched (PTC), the 7-pass membrane protein Smoothened (SMO) and the GLI transcription factors. PTC shares homology with the RND family of small-molecule transporters and it has been proposed that it interferes with SMO through metabolites. Although a conclusive picture is lacking, substantial efforts are made to identify and understand natural metabolites/sterols, including cholesterol, vitamin D3, oxysterols and glucocorticoides, that may be affected by, or influence the HH signaling cascade at the level of PTC and SMO. In this review we will elaborate the role of metabolites in HH signaling with a focus on oxysterols, and discuss advancements in modern analytical approaches in the field. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Prototype of an intertwined secondary-metabolite supercluster

    Science.gov (United States)

    Phillipp Wiemann; Chun-Jun. Guo; Jonathan M. Palmer; Relebohile Sekonyela; Clay C.C. Wang; Nancy P. Keller

    2013-01-01

    The hallmark trait of fungal secondary-metabolite gene clusters is well established, consisting of contiguous enzymatic and often regulatory gene(s) devoted to the production of a metabolite of a specific chemical class. Unexpectedly, we have found a deviation from this motif in a subtelomeric region of Aspergillus fumigatus. This region, under the...

  15. Research on generation mechanism of single event transient current generated in the semiconductor using ion accelerator

    International Nuclear Information System (INIS)

    Hirao, Toshio

    2007-01-01

    Single-event upset (SEU) is triggered when an amount of electric charges induced by energetic ion incidence exceeds a value known as a critical charge in a very short time period. Therefore, accurate evaluation of electric charge and understanding of basic mechanism of SEU are necessary for the improvement of SEU torrance of electronic devices. In this paper, the collected charges for the single event transient current induced on semiconductor by heavy ion microbeams, and application to use microbeam for single event studies are presented. (author)

  16. Multi-frequency inversion-charge pumping for charge separation and mobility analysis in high-k/InGaAs metal-oxide-semiconductor field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Djara, V.; Cherkaoui, K.; Negara, M. A.; Hurley, P. K., E-mail: paul.hurley@tyndall.ie [Tyndall National Institute, University College Cork, Dyke Parade, Cork (Ireland)

    2015-11-28

    An alternative multi-frequency inversion-charge pumping (MFICP) technique was developed to directly separate the inversion charge density (N{sub inv}) from the trapped charge density in high-k/InGaAs metal-oxide-semiconductor field-effect transistors (MOSFETs). This approach relies on the fitting of the frequency response of border traps, obtained from inversion-charge pumping measurements performed over a wide range of frequencies at room temperature on a single MOSFET, using a modified charge trapping model. The obtained model yielded the capture time constant and density of border traps located at energy levels aligned with the InGaAs conduction band. Moreover, the combination of MFICP and pulsed I{sub d}-V{sub g} measurements enabled an accurate effective mobility vs N{sub inv} extraction and analysis. The data obtained using the MFICP approach are consistent with the most recent reports on high-k/InGaAs.

  17. [Identification of saponins from Panax notoginseng in metabolites of rats].

    Science.gov (United States)

    Shen, Wen-Wen; Zhang, Yin; Qiu, Shou-Bei; Zhu, Fen-Xia; Jia, Xiao-Bin; Tang, Dao-Quan; Chen, Bin

    2017-10-01

    UPLC-QTOF-MS/MS was used to identify metabolites in rat blood, urine and feces after the administration of n-butanol extract derived from steamed notoginseng. The metabolic process of saponins came from steamed notoginseng was analyzed. The metabolites were processed by PeakView software, and identified according to the structural characteristics of prototype compounds and the accurate qualitative and quantitative changes of common metabolic pathways. Four saponins metabolites were identified based on MS/MS information of metabolites, namely ginsenoside Rh₄, Rk₃, Rk₁, Rg₅,and their 15 metabolites were verified. The metabolic pathways of the four ginsenosides in n-butanol extract included glucuronidation, desugar, sulfation, dehydromethylation, and branch loss. The metabolites of main active saponin components derived from steamed Panax notoginseng were analyzed from the perspective of qualitative analysis. And the material basis for the efficacy of steamed notoginseng was further clarified. Copyright© by the Chinese Pharmaceutical Association.

  18. Moment-Preserving Computational Approach for High Energy Charged Particle Transport

    Science.gov (United States)

    2016-05-16

    posed, but with modified cross sections such that the resulting single-event Monte Carlo simulation is computationally efficient (minutes vs . days...configurations, which are all characteristics of real world applications. In other words , it is possible to simulate real, physical phenomena using charged...0 < 0.95) ~ 1 2() ≫ 1, (3) Demonstrating that scattering is highly forward peaked. Thus, the picture of charged particle interactions

  19. Mass and Angular Distributions of Charged Dihadron Production

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Mary Clare [Michigan U.

    1990-01-01

    Experiment 711, conducted at Fermilab. provided a unique handle towards understanding valence quark scattering by studying pairs of single. charged, high transverse momentum hadrons produced in collisions of 800 GeV /c protons on fixed metal targets. The apparatus consisted of a double-arm spectrometer. calorimetrically triggered. with high momentum resolution and a large angular acceptance for all charge states of particle pairs. The experiment was designed to select those hadron pairs that carrted most of the momentum and energy of the underlying scattered quarks and gluons. The charge of such "leading" hadrons is correlated with the charge of the quark that produced it. Quantum Chromodynamics (QCD) assumes that the scattering behavior of quarks ts independent of their charge, or "flavour": Experiment 711 could test this assumption. Tilis dissertation descrtbes the analysis of the mass and angular distributions of hadron pair production for three separate charge states: +-, ++ and --. The angular distributions are found to deviate from theory predictions of flavour symmetry. Also. the mass cross sections indicate ratios of positive to negative hard-scattered particles that are larger than expected from theory. These results could warrant reconsideration of the assumptions and approximations currently made in leading-order QCD calculations.

  20. Benzene: a case study in parent chemical and metabolite interactions.

    Science.gov (United States)

    Medinsky, M A; Kenyon, E M; Schlosser, P M

    1995-12-28

    Benzene, an important industrial solvent, is also present in unleaded gasoline and cigarette smoke. The hematotoxic effects of benzene in humans are well documented and include aplastic anemia and pancytopenia, and acute myelogenous leukemia. A combination of metabolites (hydroquinone and phenol for example) is apparently necessary to duplicate the hematotoxic effect of benzene, perhaps due in part to the synergistic effect of phenol on myeloperoxidase-mediated oxidation of hydroquinone to the reactive metabolite benzoquinone. Since benzene and its hydroxylated metabolites (phenol, hydroquinone and catechol) are substrates for the same cytochrome P450 enzymes, competitive interactions among the metabolites are possible. In vivo data on metabolite formation by mice exposed to various benzene concentrations are consistent with competitive inhibition of phenol oxidation by benzene. In vitro studies of the metabolic oxidation of benzene, phenol and hydroquinone are consistent with the mechanism of competitive interaction among the metabolites. The dosimetry of benzene and its metabolites in the target tissue, bone marrow, depends on the balance of activation processes such as enzymatic oxidation and deactivation processes such as conjugation and excretion. Phenol, the primary benzene metabolite, can undergo both oxidation and conjugation. Thus, the potential exists for competition among various enzymes for phenol. However, zonal localization of Phase I and Phase II enzymes in various regions of the liver acinus regulates this competition. Biologically-based dosimetry models that incorporate the important determinants of benzene flux, including interactions with other chemicals, will enable prediction of target tissue doses of benzene and metabolites at low exposure concentrations relevant for humans.

  1. Radiation induced leakage due to stochastic charge trapping in isolation layers of nanoscale MOSFETs

    Science.gov (United States)

    Zebrev, G. I.; Gorbunov, M. S.; Pershenkov, V. S.

    2008-03-01

    The sensitivity of sub-100 nm devices to microdose effects, which can be considered as intermediate case between cumulative total dose and single event errors, is investigated. A detailed study of radiation-induced leakage due to stochastic charge trapping in irradiated planar and nonplanar devices is developed. The influence of High-K insulators on nanoscale ICs reliability is discussed. Low critical values of trapped charge demonstrate a high sensitivity to single event effect.

  2. Secondary metabolites from Eremostachys laciniata

    DEFF Research Database (Denmark)

    Calis, Ihsan; Güvenc, Aysegül; Armagan, Metin

    2008-01-01

    ), and forsythoside B (18), and five flavone derivatives, luteolin (19), luteolin 7-O-β-D-glucopyranoside (20), luteolin 7-O-(6''-O-β-D-apiofuranosyl)-β-D-glucopyranoside (21), apigenin 7-O-β-D-glucopyranoside (22), and apigenin 7-O-(6''-O-p-coumaroyl)-β-D-glucopyranoside (23). The structures of the metabolites were...... elucidated from spectroscopic (UV, IR, 1D- and 2D-NMR) and ESI-MS evidence, as well as from their specific optical rotation. The presence of these metabolites of three different classes strongly supports the close relationship of the genera Eremostachys and Phlomis....

  3. Cyanobacteria as Cell Factories to Produce Plant Secondary Metabolites

    OpenAIRE

    Xue, Yong; He, Qingfang

    2015-01-01

    Cyanobacteria represent a promising platform for the production of plant secondary metabolites. Their capacity to express plant P450 proteins, which have essential functions in the biosynthesis of many plant secondary metabolites, makes cyanobacteria ideal for this purpose, and their photosynthetic capability allows cyanobacteria to grow with simple nutrient inputs. This review summarizes the advantages of using cyanobacteria to transgenically produce plant secondary metabolites. Some techniq...

  4. Protein precipitation: an expedient procedure for the routine analysis of the plasma metabolites of [123I]IBZM

    International Nuclear Information System (INIS)

    Zea-Ponce, Yolanda; Laruelle, Marc

    1999-01-01

    Plasma metabolite analysis of the single photon emission computed tomography (SPECT) D 2 /D 3 receptor radiotracer (S)(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-2-hydroxy-3-[ 123 I] iodo-6-methoxyb enzamide ([ 123 I]IBZM) is needed for the equilibrium analysis of the SPECT data, in brain imaging studies involving bolus plus constant infusion paradigm. The purpose of these experiments was to find an appropriate procedure to expedite this analysis during routine determinations. The procedure was applied to the plasma analysis of 22 human subjects. Each plasma sample was subjected to acetonitrile protein precipitation. After separation of the pellet, the acetonitrile fraction contained 91%±2% (n=88) of the mixture of labeled metabolites and parent compound. The recovery coefficient of unmetabolized [ 123 I]IBZM determined with an standard plasma sample was 95%±2% (n=22). The percent parent compound present in the extracted fraction, measured by high performance liquid chromatography, was 16%±9% (n=85) and the percent metabolites was 84%±9% (n=85). Free fraction determination (f 1 , fraction of radiotracer unbound to protein), was 4%±0.8% (n=22). Free fraction of parent was 15%±8% (n=85). The results indicate that acetonitrile protein precipitation is an adequate method for the analysis of the [ 123 I]IBZM plasma metabolites

  5. An update on organohalogen metabolites produced by basidiomycetes

    NARCIS (Netherlands)

    Field, J.A.; Wijnberg, J.B.P.A.

    2003-01-01

    Basidiomycetes are an ecologically important group of higher fungi known for their widespread capacity to produce organohalogen metabolites. To date, 100 different organohalogen metabolites (mostly chlorinated) have been identified from strains in 70 genera of Basidiomycetes. This manuscript

  6. High and ultra-high resolution metabolite mapping of the human brain using 1H FID MRSI at 9.4T.

    Science.gov (United States)

    Nassirpour, Sahar; Chang, Paul; Henning, Anke

    2018-03-01

    Magnetic resonance spectroscopic imaging (MRSI) is a promising technique for mapping the spatial distribution of multiple metabolites in the human brain. These metabolite maps can be used as a diagnostic tool to gain insight into several biochemical processes and diseases in the brain. In comparison to lower field strengths, MRSI at ultra-high field strengths benefits from a higher signal to noise ratio (SNR) as well as higher chemical shift dispersion, and hence spectral resolution. This study combines the benefits of an ultra-high field magnet with the advantages of an ultra-short TE and TR single-slice FID-MRSI sequence (such as negligible J-evolution and loss of SNR due to T 2 relaxation effects) and presents the first metabolite maps acquired at 9.4T in the healthy human brain at both high (voxel size of 97.6µL) and ultra-high (voxel size of 24.4µL) spatial resolutions in a scan time of 11 and 46min respectively. In comparison to lower field strengths, more anatomically-detailed maps with higher SNR from a larger number of metabolites are shown. A total of 12 metabolites including glutamate (Glu), glutamine (Gln), N-acetyl-aspartyl-glutamate (NAAG), Gamma-aminobutyric acid (GABA) and glutathione (GSH) are reliably mapped. Comprehensive description of the methodology behind these maps is provided. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Single bunched beam generation without subharmonic prebuncher

    International Nuclear Information System (INIS)

    Kobayashi, T.; Tagawa, S.

    1995-01-01

    The intensity of the accelerated single bunched electron beam depends on the performance of the electron gun and the fast cathode pulser. The electron beam is emitted by a Y-796 cathode assembly with a cathode of 2 cm 2 (8 A/cm 2 ), and an extracted voltage of 90 kV. The maximum charge of the single bunched beam was attained at 1.5 nC/pulse using SHB. Recently, a single bunched beam has been generated by an ultrafast cathode pulser (rise and fall time <100 ps pulse height -2 kV at 50 Ω) without SHB. The charge of the accelerated electron beam is about 40 pC/pulse (pulse width <10 ps) without the production of a satellite beam. This result show that a single bunched beam can be produced by the linear accelerator without SHB. ((orig.))

  8. Metabolome analysis - mass spectrometry and microbial primary metabolites

    DEFF Research Database (Denmark)

    Højer-Pedersen, Jesper Juul

    2008-01-01

    , and therefore sample preparation is critical for metabolome analysis. The three major steps in sample preparation for metabolite analysis are sampling, extraction and concentration. These three steps were evaluated for the yeast Saccharomyces cerevisiae with primary focus on analysis of a large number...... of metabolites by one method. The results highlighted that there were discrepancies between different methods. To increase the throughput of cultivation, S. cerevisiae was grown in microtitier plates (MTPs), and the growth was found to be comparable with cultivations in shake flasks. The carbon source was either...... a theoretical metabolome. This showed that in combination with the specificity of MS up to 84% of the metabolites can be identified in a high-accuracy ESI-spectrum. A total of 66 metabolites were systematically analyzed by positive and negative ESI-MS/MS with the aim of initiating a spectral library for ESI...

  9. Role of molecular charge in nucleocytoplasmic transport.

    Directory of Open Access Journals (Sweden)

    Alexander Goryaynov

    Full Text Available Transport of genetic materials and proteins between the nucleus and cytoplasm of eukaryotic cells is mediated by nuclear pore complexes (NPCs. A selective barrier formed by phenylalanine-glycine (FG nucleoporins (Nups with net positive charges in the NPC allows for passive diffusion of signal-independent small molecules and transport-receptor facilitated translocation of signal-dependent cargo molecules. Recently, negative surface charge was postulated to be another essential criterion for selective passage through the NPC. However, the charge-driven mechanism in determining the transport kinetics and spatial transport route for either passive diffusion or facilitated translocation remains obscure. Here we employed high-speed single-molecule fluorescence microscopy with an unprecedented spatiotemporal resolution of 9 nm and 400 µs to uncover these mechanistic fundamentals for nuclear transport of charged substrates through native NPCs. We found that electrostatic interaction between negative surface charges on transiting molecules and the positively charged FG Nups, although enhancing their probability of binding to the NPC, never plays a dominant role in determining their nuclear transport mode or spatial transport route. A 3D reconstruction of transport routes revealed that small signal-dependent endogenous cargo protein constructs with high positive surface charges that are destined to the nucleus, rather than repelled from the NPC as suggested in previous models, passively diffused through an axial central channel of the NPC in the absence of transport receptors. Finally, we postulated a comprehensive map of interactions between transiting molecules and FG Nups during nucleocytoplasmic transport by combining the effects of molecular size, signal and surface charge.

  10. Transition density of charge-exchange processes

    International Nuclear Information System (INIS)

    Lovas, R.G.

    1983-01-01

    The transition density between parent and analogue states is studied with special reference to its role in charge-exchange nuclear reactions. The structure of the target nucleus is described in a perturbative approach, in which the Coulomb and asymmetry potentials mix the eigenstates of a charge-independent single-particle Hamiltonian. In this model formulae are derived for the transition density, the Coulomb displacement energy and the neutron-proton density difference, and their relationship is used to estimate the transition density. This estimate shows that: the largest contribution comes from the density of the excess neutrons; the weight of the Coulomb-mixing effect is small up to excess neutron number 10, and grows rapidly beyond; the weight of the core polarization term induced by the excess neutrons is modest and is the same for all nuclei. It is indicated that the Coulomb effect may explain the departure from the Lane model of nucleon charge-exchange scattering found for heavy nuclei, whereas the core polarization may account for the observed anomalous dependence of the deg 0 pion charge-exchange cross section on the number of excess neutrons. (author)

  11. Tau lepton charge asymmetry and new physics at the LHC

    International Nuclear Information System (INIS)

    Gupta, Sudhir Kumar; Valencia, German

    2011-01-01

    We consider the possibility of studying new physics that singles out the tau lepton at the LHC. We concentrate on the tau lepton charge asymmetry in τ + τ - pair production as a tool to probe this physics beyond the standard model. We consider two generic scenarios for the new physics. We first study a nonuniversal Z' boson as an example of a new resonance that can single out tau leptons. We then consider vector lepto-quarks coupling the first-generation quarks with the third-generation leptons as an example of nonresonant new physics. We find that in both cases the charge asymmetry can be sufficiently sensitive to the new physics to provide useful constraints at the LHC.

  12. Theory and simulation of charge transfer through DNA - nanotube contacts

    International Nuclear Information System (INIS)

    Rink, Gunda; Kong Yong; Koslowski, Thorsten

    2006-01-01

    We address the problem of charge transfer between a single-stranded adenine oligomer and semiconducting boron nitride nanotubes from a theoretical and numerical perspective. The model structures have been motivated by computer simulations; sample geometries are used as the input of an electronic structure theory that is based upon an extended Su-Schrieffer-Heeger Hamiltonian. By analyzing the emerging potential energy surfaces, we obtain hole transfer rates via Marcus' theory of charge transfer. In the presence of nanotubes, these rates exceed those of isolated DNA single strands by a factor of up to 10 4 . This enhancement can be rationalized and quantified as a combination of a template effect and the participation of the tube within a superexchange mechanism

  13. On measurement of charge behavior with super high velocity formed in semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Hirao, Toshio; Sakai, Takuro; Hamano, Tsuyoshi; Nashiyama, Isamu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Nemoto, Norio; Matsuda, Sumio

    1996-12-01

    The basic process of single event phenomenon of the semiconductor element consists of formation of electron and positive hole pair due to penetration of incident particle and collection of small number of carrier into pn-junction added with inverse bias. This collecting process has a rapid process of about 200 ps and a late process reaching to some nanoseconds. And, it is an important problem to develop radiation resistant element of superconducting element usable for the space environment to acquire single event parameter by directly observing charge collection using pn-junction diode constructing basic structure of the semiconductor element. At present, an experiment on the single event phenomenon in actual device is executed by using cyclotron of TIARA irradiation facility in Takasaki Radiation Chemistry Research Establishment, JAERI. On the other hand, the experiments on mechanism elucidation of the single event phenomenon and so on are conducting by using heavy ion microbeam installed at tandem accelerator. As an experiment result measured high speed charge collection on irradiating the heavy ion microbeam into the semiconductor element, following items were found: (1) The single event transient current waveform becomes high in its peak and many in collected charge with magnitude of LET, (2) rise of the transient current waveform formed in each ion specie shows a shift to long time side with increase of LET, and so forth. (G.K.)

  14. Charge transfer devices and their application in physics

    Energy Technology Data Exchange (ETDEWEB)

    Soroko, L M [Joint Inst. for Nuclear Research, Dubna (USSR)

    1979-01-01

    Physical properties and technical specifications of charge transfer devices (CTD) are reviewed. The CTD are semiconductor devices based on silicon single crystals. The limiting charge density of the CTD, their efficiency of charge transfer, the background noise and radiation effects are considered. Fast response and low energy consumption are characteristic features of the devices. The application of the CTD in storage devices, real time spectral data processing systems and in streamer chambers is described. The algorithms of topological transformations in the stage of scanning particle track images, which can be realized with the help of the CTD are shortly considered. It is pointed out that applications of the CTD in different fields of science and technology are numerous and expanding.

  15. Spin-coupled charge dynamics in layered manganite crystals

    CERN Document Server

    Tokura, Y; Ishikawa, T

    1998-01-01

    Anisotropic charge dynamics has been investigated for single crystals of layered manganites, La sub 2 sub - sub 2 sub x Sr sub 1 sub + sub 2 sub x Mn sub 2 O sub 7 (0.3<=X<=0.5). Remarkable variations in the magnetic structure and in the charge-transport properties are observed by changing the doping level x . A crystal with x = 0.3 behaves like a 2-dimensional ferromagnetic metal in the temperature region between approx 90 K and approx 270 K and shows an interplane tunneling magnetoresistance at lower temperatures which is sensitive to the interplane magnetic coupling between the adjacent MnO sub 2 bilayers. Optical probing of these layered manganites has also clarified the highly anisotropic and incoherent charge dynamics.

  16. Irradiation of zinc single crystal with 500 keV singly-charged carbon ions: surface morphology, structure, hardness, and chemical modifications

    Science.gov (United States)

    Waqas Khaliq, M.; Butt, M. Z.; Saleem, Murtaza

    2017-07-01

    Cylindrical specimens of (1 0 4) oriented zinc single crystal (diameter  =  6 mm and length  =  5 mm) were irradiated with 500 keV C+1 ions with the help of a Pelletron accelerator. Six specimens were irradiated in an ultra-high vacuum (~10‒8 Torr) with different ion doses, namely 3.94  ×  1014, 3.24  ×  1015, 5.33  ×  1015, 7.52  ×  1015, 1.06  ×  1016, and 1.30  ×  1016 ions cm-2. A field emission scanning electron microscope (FESEM) was utilized for the morphological study of the irradiated specimens. Formation of nano- and sub-micron size rods, clusters, flower- and fork-like structures, etc, was observed. Surface roughness of the irradiated specimens showed an increasing trend with the ions dose. Energy dispersive x-ray spectroscopy (EDX) helped to determine chemical modifications in the specimens. It was found that carbon content varied in the range 22.86-31.20 wt.% and that oxygen content was almost constant, with an average value of 10.16 wt.%. The balance content was zinc. Structural parameters, i.e. crystallite size and lattice strain, were determined by Williamson-Hall analysis using x-ray diffraction (XRD) patterns of the irradiated specimens. Both crystallite size and lattice strain showed a decreasing trend with the increasing ions dose. A good linear relationship between crystallite size and lattice strain was observed. Surface hardness depicted a decreasing trend with the ions dose and followed an inverse Hall-Petch relation. FTIR spectra of the specimens revealed that absorption bands gradually diminish as the dose of singly-charged carbon ions is increased from 3.94  ×  1014 ions cm-1 to 1.30  ×  1016 ions cm-1. This indicates progressive deterioration of chemical bonds with the increase in ion dose.

  17. New secondary metabolites of phenylbutyrate in humans and rats.

    Science.gov (United States)

    Kasumov, Takhar; Brunengraber, Laura L; Comte, Blandine; Puchowicz, Michelle A; Jobbins, Kathryn; Thomas, Katherine; David, France; Kinman, Renee; Wehrli, Suzanne; Dahms, William; Kerr, Douglas; Nissim, Itzhak; Brunengraber, Henri

    2004-01-01

    Phenylbutyrate is used to treat inborn errors of ureagenesis, malignancies, cystic fibrosis, and thalassemia. High-dose phenylbutyrate therapy results in toxicity, the mechanism of which is unexplained. The known metabolites of phenylbutyrate are phenylacetate, phenylacetylglutamine, and phenylbutyrylglutamine. These are excreted in urine, accounting for a variable fraction of the dose. We identified new metabolites of phenylbutyrate in urine of normal humans and in perfused rat livers. These metabolites result from interference between the metabolism of phenylbutyrate and that of carbohydrates and lipids. The new metabolites fall into two categories, glucuronides and phenylbutyrate beta-oxidation side products. Two questions are raised by these data. First, is the nitrogen-excreting potential of phenylbutyrate diminished by ingestion of carbohydrates or lipids? Second, does competition between the metabolism of phenylbutyrate, carbohydrates, and lipids alter the profile of phenylbutyrate metabolites? Finally, we synthesized glycerol esters of phenylbutyrate. These are partially bioavailable in rats and could be used to administer large doses of phenylbutyrate in a sodium-free, noncaustic form.

  18. Novel urinary metabolite of d-delta-tocopherol in rats

    International Nuclear Information System (INIS)

    Chiku, S.; Hamamura, K.; Nakamura, T.

    1984-01-01

    A novel metabolite of d-delta-tocopherol was isolated from the urine of rats given d-3,4-[ 3 H 2 ]-delta-tocopherol intravenously. The metabolite was collected from the urine of rats given d-delta-tocopherol in the same manner as that of the labeled compound. It was found that the metabolites consisted of sulfate conjugates. The portion of the major metabolite released with sulfatase was determined to be 2,8-dimethyl-2-(2'-carboxyethyl)-6-chromanol by infrared spectra, nuclear magnetic resonance spectra, and mass spectra. The proposed structure was confirmed by comparing the analytical results with those of a synthetically derived compound. As a result of the structural elucidation of this novel metabolite, a pathway for the biological transformation of delta-tocopherol is proposed which is different from that of alpha-tocopherol. A characteristic feature of the pathway is the absence of any opening of the chroman ring throughout the sequence

  19. Circulating prostacyclin metabolites in the dog

    International Nuclear Information System (INIS)

    Taylor, B.M.; Shebuski, R.J.; Sun, F.F.

    1983-01-01

    The present study was designed to determine the concentration of prostacyclin (PGI2) metabolites in the blood of the dog. After a bolus i.v. dose of [11 beta- 3 H]PGI2 (5 micrograms/kg) into each of five dogs, blood samples were withdrawn at 0.33, 0.67, 1, 3, 5, 20, 30, 60 and 120 min postdrug administration. Plasma samples were extracted and the radioactive components were analyzed by two-dimensional thin-layer chromatography with autoradiofluorography and radio-high-performance liquid chromatography. The compounds were identified by comparing their mobility with synthetic standards; only parallel responses observed in both tests constituted positive identification. Seven metabolites were identified by these two techniques: 6-keto-prostaglandin (PG)F1 alpha; 6-keto-PGE1; 2,3-dinor-6-keto-PGF 1 alpha; 2,3-dinor-13,14-dihydro-6,15-diketo-20-carboxyl PGF 1 alpha; and 2,3,18,19-tetranor-13,14-dihydro-6,15-diketo-20-carboxyl PGF 1 alpha. Several additional compounds, both polar and nonpolar in nature, which did not co-chromatograph with any of our standards were also detected. Early samples consisted predominantly of 6-keto-PGF 1 alpha and other 20-carbon metabolites. By 30 min, the predominant metabolites were the 16- and 18-carbon dicarboxylic acids. By 60 min, 85% of the radioactivity was associated with two unidentified polar compounds. The evidence suggests that 6-keto-PGF 1 alpha probably reflects only the transient levels of freshly entering PGI2 in the circulation, whereas levels of the most polar metabolites (e.g., dihydro-diketo-carboxyl tetranor-PGF 2 alpha) may be a better measure of the overall PGI2 presence due to its longer half-life in circulation

  20. Search for doubly-charged Higgs boson production at HERA

    Science.gov (United States)

    H1 Collaboration; Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J. G.; Coughlan, J. A.; Cox, B. E.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Dau, W. D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Flucke, G.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Lüke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Marti, L.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Plačakytė, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A. J.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauvan, E.; Schätzel, S.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Stiewe, J.; Stoilov, A.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Traynor, D.; Truöl, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Urban, M.; Usik, A.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-07-01

    A search for the single production of doubly-charged Higgs bosons H in ep collisions is presented. The signal is searched for via the Higgs decays into a high mass pair of same charge leptons, one of them being an electron. The analysis uses up to 118 pb-1 of ep data collected by the H1 experiment at HERA. No evidence for doubly-charged Higgs production is observed and mass dependent upper limits are derived on the Yukawa couplings h of the Higgs boson to an electron lepton pair. Assuming that the doubly-charged Higgs only decays into an electron and a muon via a coupling of electromagnetic strength h=4πα≃0.3, a lower limit of 141 GeV on the H mass is obtained at the 95% confidence level. For a doubly-charged Higgs decaying only into an electron and a tau and a coupling h≃0.3, masses below 112 GeV are ruled out.

  1. Measurement of the atmospheric muon charge ratio with the OPERA detector

    CERN Document Server

    Agafonova, N.; Aoki, S.; Ariga, A.; Ariga, T.; Autiero, D.; Badertscher, A.; Bagulya, A.; Bertolin, A.; Besnier, M.; Bick, D.; Boyarkin, V.; Bozza, C.; Brugiere, T.; Brugnera, R.; Brunetti, G.; Buontempo, S.; Cazes, A.; Chaussard, L.; Chernyavsky, M.; Chiarella, V.; Chon-Sen, N.; Chukanov, A.; Cozzi, M.; D'Amato, G.; Dal Corso, F.; D'Ambrosio, N.; De Lellis, G.; Declais, Y.; De Serio, M.; Di Capua, F.; Di Ferdinando, D.; Di Giovanni, A.; Di Marco, N.; Dmitrievski, S.; Dracos, M.; Duchesneau, D.; Dusini, S.; Ebert, J.; Egorov, O.; Enikeev, R.; Ereditato, A.; Esposito, L.S.; Favier, J.; Felici, G.; Ferber, T.; Fini, R.; Frekers, D.; Fukuda, T.; Fukushima, C.; Galkin, V.I.; Garfagnini, A.; Giacomelli, G.; Giorgini, M.; Goellnitz, C.; Goldberg, J.; Golubkov, D.; Goncharova, L.; Gornushkin, Y.; Grella, G.; Grianti, F.; Guler, M.; Gustavino, C.; Hagner, C.; Hamada, K.; Hara, T.; Hierholzer, M.; Hoshino, K.; Ieva, M.; Jakovcic, K.; Jollet, C.; Juget, F.; Kazuyama, M.; Kim, S.H.; Kimura, M.; Klicek, B.; Knuesel, J.; Kodama, K.; Komatsu, M.; Kose, U.; Kreslo, I.; Kubota, H.; Lazzaro, C.; Lenkeit, J.; Ljubicic, A.; Longhin, A.; Lutter, G.; Malgin, A.; Mandrioli, G.; Marotta, A.; Marteau, J.; Matsuo, T.; Matveev, V.; Mauri, N.; Medinaceli, E.; Meisel, F.; Meregaglia, A.; Migliozzi, P.; Mikado, S.; Miyamoto, S.; Monacelli, P.; Morishima, K.; Moser, U.; Muciaccia, M.T.; Naganawa, N.; Naka, T.; Nakamura, M.; Nakano, T.; Naumov, D.; Nikitina, V.; Niwa, K.; Nonoyama, Y.; Ogawa, S.; Olchevski, A.; Oldorf, C.; Orlova, G.; Osedlo, V.; Paniccia, M.; Paoloni, A.; Park, B.D.; Park, I.G.; Pastore, A.; Patrizii, L.; Pennacchio, E.; Pessard, H.; Pilipenko, V.; Pistillo, C.; Policastro, G.; Polukhina, N.; Pozzato, M.; Pretzl, K.; Publichenko, P.; Pupilli, F.; Rescigno, R.; Roganova, T.; Rokujo, H.; Romano, G.; Rosa, G.; Rostovtseva, I.; Rubbia, A.; Russo, A.; Ryasny, V.; Ryazhskaya, O.; Sato, O.; Sato, Y.; Schembri, A.; Schmidt Parzefall, W.; Schroeder, H.; Scotto Lavina, L.; Sheshukov, A.; Shibuya, H.; Simone, S.; Sioli, M.; Sirignano, C.; Sirri, G.; Song, J.S.; Spinetti, M.; Stanco, L.; Starkov, N.; Stipcevic, M.; Strauss, T.; Strolin, P.; Takahashi, S.; Tenti, M.; Terranova, F.; Tezuka, I.; Tioukov, V.; Tolun, P.; Tran, T.; Tufanli, S.; Vilain, P.; Vladimirov, M.; Votano, L.; Vuilleumier, J.L.; Wilquet, G.; Wonsak, B.; Yakushev, V.; Yoon, C.S.; Yoshioka, T.; Yoshida, J.; Zaitsev, Y.; Zemskova, S.; Zghiche, A.; Zimmermann, R.

    2010-01-01

    The OPERA detector at the Gran Sasso underground laboratory (LNGS) was used to measure the atmospheric muon charge ratio in the TeV energy region. We analyzed 403069 atmospheric muons corresponding to 113.4 days of livetime during the 2008 CNGS run. We computed separately the muon charge ratio for single and for multiple muon events in order to select different energy regions of the primary cosmic ray spectrum and to test the charge ratio dependence on the primary composition. The measured charge ratio values were corrected taking into account the charge-misidentification errors. Data have also been grouped in five bins of the "vertical surface energy". A fit to a simplified model of muon production in the atmosphere allowed the determination of the pion and kaon charge ratios weighted by the cosmic ray energy spectrum.

  2. Ultra-thin MoS{sub 2} irradiated with highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Hopster, J.; Kozubek, R.; Krämer, J.; Sokolovsky, V.; Schleberger, M., E-mail: marika.schleberger@uni-due.de

    2013-12-15

    Single MoS{sub 2} layers exfoliated on KBr have been irradiated with highly charged Xe ions, i.e. with Xe{sup 35+} and Xe{sup 40+}. By atomic force microscopy (AFM) we identified pits and hillocks induced by single ion impacts. The latter ones appear on single layer and bulk-like MoS{sub 2} after both irradiations, whereas their diameter and height apparently depend on the charge state q and layer number. By comparison of contact mode and tapping mode AFM measurements we deduce that these ion induced defects are topographical hillocks accompanied by an enhanced friction. In contrast to this, pit-like structures were only observed on single layer MoS{sub 2} irradiated with q = 40. Taking into account the well known ion induced pit formation on KBr due to defect mediated sputtering, we deduce that pit formation takes place in the substrate and not in the MoS{sub 2} layer.

  3. Charge reconstruction in large-area photomultipliers

    Science.gov (United States)

    Grassi, M.; Montuschi, M.; Baldoncini, M.; Mantovani, F.; Ricci, B.; Andronico, G.; Antonelli, V.; Bellato, M.; Bernieri, E.; Brigatti, A.; Brugnera, R.; Budano, A.; Buscemi, M.; Bussino, S.; Caruso, R.; Chiesa, D.; Corti, D.; Dal Corso, F.; Ding, X. F.; Dusini, S.; Fabbri, A.; Fiorentini, G.; Ford, R.; Formozov, A.; Galet, G.; Garfagnini, A.; Giammarchi, M.; Giaz, A.; Insolia, A.; Isocrate, R.; Lippi, I.; Longhitano, F.; Lo Presti, D.; Lombardi, P.; Marini, F.; Mari, S. M.; Martellini, C.; Meroni, E.; Mezzetto, M.; Miramonti, L.; Monforte, S.; Nastasi, M.; Ortica, F.; Paoloni, A.; Parmeggiano, S.; Pedretti, D.; Pelliccia, N.; Pompilio, R.; Previtali, E.; Ranucci, G.; Re, A. C.; Romani, A.; Saggese, P.; Salamanna, G.; Sawy, F. H.; Settanta, G.; Sisti, M.; Sirignano, C.; Spinetti, M.; Stanco, L.; Strati, V.; Verde, G.; Votano, L.

    2018-02-01

    Large-area PhotoMultiplier Tubes (PMT) allow to efficiently instrument Liquid Scintillator (LS) neutrino detectors, where large target masses are pivotal to compensate for neutrinos' extremely elusive nature. Depending on the detector light yield, several scintillation photons stemming from the same neutrino interaction are likely to hit a single PMT in a few tens/hundreds of nanoseconds, resulting in several photoelectrons (PEs) to pile-up at the PMT anode. In such scenario, the signal generated by each PE is entangled to the others, and an accurate PMT charge reconstruction becomes challenging. This manuscript describes an experimental method able to address the PMT charge reconstruction in the case of large PE pile-up, providing an unbiased charge estimator at the permille level up to 15 detected PEs. The method is based on a signal filtering technique (Wiener filter) which suppresses the noise due to both PMT and readout electronics, and on a Fourier-based deconvolution able to minimize the influence of signal distortions—such as an overshoot. The analysis of simulated PMT waveforms shows that the slope of a linear regression modeling the relation between reconstructed and true charge values improves from 0.769 ± 0.001 (without deconvolution) to 0.989 ± 0.001 (with deconvolution), where unitary slope implies perfect reconstruction. A C++ implementation of the charge reconstruction algorithm is available online at [1].

  4. Single spin asymmetries in charged kaon production from semi-inclusive deep inelastic scattering on a transversely polarized 3He target

    Science.gov (United States)

    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

  5. Single-Molecule Electronics: Chemical and Analytical Perspectives.

    Science.gov (United States)

    Nichols, Richard J; Higgins, Simon J

    2015-01-01

    It is now possible to measure the electrical properties of single molecules using a variety of techniques including scanning probe microcopies and mechanically controlled break junctions. Such measurements can be made across a wide range of environments including ambient conditions, organic liquids, ionic liquids, aqueous solutions, electrolytes, and ultra high vacuum. This has given new insights into charge transport across molecule electrical junctions, and these experimental methods have been complemented with increasingly sophisticated theory. This article reviews progress in single-molecule electronics from a chemical perspective and discusses topics such as the molecule-surface coupling in electrical junctions, chemical control, and supramolecular interactions in junctions and gating charge transport. The article concludes with an outlook regarding chemical analysis based on single-molecule conductance.

  6. Charge dependence of one and two electron processes in collisions between hydrogen molecules and fast projectiles

    International Nuclear Information System (INIS)

    Wells, E.; Ben-Itzhak, I.; Carnes, K.D.; Krishnamurthi, V.

    1996-01-01

    The ratio of double- to single-ionization (DI/SI) as well as the ratio of ionization-excitation to single-ionization (IE/SI) in hydrogen molecules was studied by examining the effect of the projectile charge on these processes. The DI/SI and IE/SI ratios were measured using the coincidence time of flight technique at a fixed velocity (1 MeV/amu) over a range of projectile charge states (q = 1-9,14,20). Preliminary results indicate that for a highly charged F 9+ projectile the DI/SI and IE/SI ratios are 6.8% and 24.7%, respectively, a large increase from the ratios of 0.13% and 1.95%, respectively, for H + projectiles. For low charge states, the DI/SI is negligible relative to the IE/SI ratio, while for more highly charged projectiles the DI/SI ratio becomes comparable to the IE/SI ratio. This indicates that double-ionization increases much more rapidly with projectile charge than ionization-excitation

  7. Pharmacokinetics of ifosfamide and some metabolites in children

    NARCIS (Netherlands)

    Kaijser, G. P.; de Kraker, J.; Bult, A.; Underberg, W. J.; Beijnen, J. H.

    1998-01-01

    The pharmacokinetics of ifosfamide and some metabolites in children was investigated. The patients received various doses of ifosfamide, mostly by continuous infusion, over several days. The penetration of ifosfamide and its metabolites into the cerebrospinal fluid was also studied in four cases.

  8. Novel pyrazine metabolites found in polymyxin biosynthesis by Paenibacillus polymyxa

    DEFF Research Database (Denmark)

    Beck, Hans Christian; Hansen, Anne M; Lauritsen, Frants R

    2003-01-01

    A complex mixture of methyl-branched alkyl-substituted pyrazines was found in the growth medium of the polymyxin-producing bacterium Paenibacillus polymyxa, and of these, seven are new natural compounds. A total of 19 pyrazine metabolites were identified. The dominant metabolite was 2,5-diisoprop......A complex mixture of methyl-branched alkyl-substituted pyrazines was found in the growth medium of the polymyxin-producing bacterium Paenibacillus polymyxa, and of these, seven are new natural compounds. A total of 19 pyrazine metabolites were identified. The dominant metabolite was 2...

  9. NMR-based metabolite profiling of human milk: A pilot study of methods for investigating compositional changes during lactation

    International Nuclear Information System (INIS)

    Wu, Junfang; Domellöf, Magnus; Zivkovic, Angela M.; Larsson, Göran; Öhman, Anders; Nording, Malin L.

    2016-01-01

    Low-molecular-weight metabolites in human milk are gaining increasing interest in studies of infant nutrition. In the present study, the milk metabolome from a single mother was explored at different stages of lactation. Metabolites were extracted from sample aliquots using either methanol/water (MeOH/H_2O) extraction or ultrafiltration. Nuclear magnetic resonance (NMR) spectroscopy was used for metabolite identification and quantification, and multi- and univariate statistical data analyses were used to detect changes over time of lactation. Compared to MeOH/H_2O extraction, ultrafiltration more efficiently reduced the interference from lipid and protein resonances, thereby enabling the identification and quantification of 36 metabolites. The human milk metabolomes at the early (9–24 days after delivery) and late (31–87 days after delivery) stages of lactation were distinctly different according to multi- and univariate statistics. The late lactation stage was characterized by significantly elevated concentrations of lactose, choline, alanine, glutamate, and glutamine, as well as by reduced levels of citrate, phosphocholine, glycerophosphocholine, and N-acetylglucosamine. Our results indicate that there are significant compositional changes of the human milk metabolome also in different phases of the matured lactation stage. These findings complement temporal studies on the colostrum and transitional metabolome in providing a better understanding of the nutritional variations received by an infant. - Highlights: • 36 metabolites were simultaneously quantified in human milk by NMR. • Ultrafiltration more efficiently reduces interferences than MeOH/H_2O extraction. • Compositional changes of the human milk exist during the matured lactation stage.

  10. NMR-based metabolite profiling of human milk: A pilot study of methods for investigating compositional changes during lactation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junfang [Department of Chemistry, Umeå University (Sweden); Domellöf, Magnus [Department of Clinical Sciences, Pediatrics, Umeå University (Sweden); Zivkovic, Angela M. [Foods for Health Institute, University of California, Davis, CA (United States); Department of Nutrition, University of California, Davis, CA (United States); Larsson, Göran [Department of Medical Biochemistry and Biophysics, Unit of Research, Education and Development-Östersund, Umeå University (Sweden); Öhman, Anders, E-mail: anders.ohman01@umu.se [Department of Pharmacology and Clinical Neuroscience, Umeå University (Sweden); Nording, Malin L., E-mail: malin.nording@umu.se [Department of Chemistry, Umeå University (Sweden)

    2016-01-15

    Low-molecular-weight metabolites in human milk are gaining increasing interest in studies of infant nutrition. In the present study, the milk metabolome from a single mother was explored at different stages of lactation. Metabolites were extracted from sample aliquots using either methanol/water (MeOH/H{sub 2}O) extraction or ultrafiltration. Nuclear magnetic resonance (NMR) spectroscopy was used for metabolite identification and quantification, and multi- and univariate statistical data analyses were used to detect changes over time of lactation. Compared to MeOH/H{sub 2}O extraction, ultrafiltration more efficiently reduced the interference from lipid and protein resonances, thereby enabling the identification and quantification of 36 metabolites. The human milk metabolomes at the early (9–24 days after delivery) and late (31–87 days after delivery) stages of lactation were distinctly different according to multi- and univariate statistics. The late lactation stage was characterized by significantly elevated concentrations of lactose, choline, alanine, glutamate, and glutamine, as well as by reduced levels of citrate, phosphocholine, glycerophosphocholine, and N-acetylglucosamine. Our results indicate that there are significant compositional changes of the human milk metabolome also in different phases of the matured lactation stage. These findings complement temporal studies on the colostrum and transitional metabolome in providing a better understanding of the nutritional variations received by an infant. - Highlights: • 36 metabolites were simultaneously quantified in human milk by NMR. • Ultrafiltration more efficiently reduces interferences than MeOH/H{sub 2}O extraction. • Compositional changes of the human milk exist during the matured lactation stage.

  11. Assessing the associations of blood metabolites with osteoporosis: a Mendelian randomization study.

    Science.gov (United States)

    Liu, Li; Wen, Yan; Zhang, Lei; Xu, Peng; Liang, Xiao; Du, Yanan; Li, Ping; He, Awen; Fan, QianRui; Hao, Jingcan; Wang, Wenyu; Guo, Xiong; Shen, Hui; Tian, Qing; Zhang, Feng; Deng, Hong-Wen

    2018-03-01

    Osteoporosis is a metabolic bone disease. The impact of blood metabolites on the development of osteoporosis remains elusive now. To explore the relationship between blood metabolites and osteoporosis. We used 2,286 unrelated Caucasian subjects as discovery samples and 3,143 unrelated Caucasian subjects from the Framingham heart study (FHS) as replication samples. Bone mineral density (BMD) were measured using dual-energy X-ray absorptiometry. Genome-wide SNP genotyping was performed using Affymetrix Human SNP Array 6.0 (for discovery samples) and Affymetrix SNP 500K and 50K array (for FHS replication samples). The SNP sets significantly associated with blood metabolites were obtained from a published whole-genome sequencing study. For each subject, the genetic risk score (GRS) of metabolite was calculated from the genotype data of metabolite associated SNP sets. Pearson correlation analysis was conducted to evaluate the potential impact of blood metabolites on the variations bone phenotypes. 10,000 permutations were conducted to calculate the empirical P value and false discovery rate (FDR). 481 blood metabolites were analyzed in this study. We identified multiple blood metabolites associated with hip BMD, such as 1,5-anhydroglucitol(1,5-AG) (Pdiscovery metabolites on the variations of BMD, and identified several candidate blood metabolites for osteoporosis.

  12. Metabolomics and Cheminformatics Analysis of Antifungal Function of Plant Metabolites.

    Science.gov (United States)

    Cuperlovic-Culf, Miroslava; Rajagopalan, NandhaKishore; Tulpan, Dan; Loewen, Michele C

    2016-09-30

    Fusarium head blight (FHB), primarily caused by Fusarium graminearum , is a devastating disease of wheat. Partial resistance to FHB of several wheat cultivars includes specific metabolic responses to inoculation. Previously published studies have determined major metabolic changes induced by pathogens in resistant and susceptible plants. Functionality of the majority of these metabolites in resistance remains unknown. In this work we have made a compilation of all metabolites determined as selectively accumulated following FHB inoculation in resistant plants. Characteristics, as well as possible functions and targets of these metabolites, are investigated using cheminformatics approaches with focus on the likelihood of these metabolites acting as drug-like molecules against fungal pathogens. Results of computational analyses of binding properties of several representative metabolites to homology models of fungal proteins are presented. Theoretical analysis highlights the possibility for strong inhibitory activity of several metabolites against some major proteins in Fusarium graminearum , such as carbonic anhydrases and cytochrome P450s. Activity of several of these compounds has been experimentally confirmed in fungal growth inhibition assays. Analysis of anti-fungal properties of plant metabolites can lead to the development of more resistant wheat varieties while showing novel application of cheminformatics approaches in the analysis of plant/pathogen interactions.

  13. Metabolite Profiling of Candidatus Liberibacter Infection in Hamlin Sweet Oranges.

    Science.gov (United States)

    Hung, Wei-Lun; Wang, Yu

    2018-04-18

    Huanglongbing (HLB), also known as citrus greening disease, caused by Candidatus Liberibacter asiaticus (CLas), is considered the most serious citrus disease in the world. CLas infection has been shown to greatly affect metabolite profiles in citrus fruits. However, because of uneven distribution of CLas throughout the tree and a minimum bacterial titer requirement for polymerase chain reaction (PCR) detection, the infected trees may test false negative. To prevent this, metabolites of healthy Hamlin oranges (CLas-) obtained from the citrus undercover protection systems (CUPS) were investigated. Comparison of the metabolite profile of juice obtained from CLas- and CLas+ (asymptomatic and symptomatic) trees revealed significant differences in both volatile and nonvolatile metabolites. However, no consistent pattern could be observed in alcohols, esters, sesquiterpenes, sugars, flavanones, and limonoids as compared to previous studies. These results suggest that CLas may affect metabolite profiles of citrus fruits earlier than detecting infection by PCR. Citric acid, nobiletin, malic acid, and phenylalanine were identified as the metabolic biomarkers associated with the progression of HLB. Thus, the differential metabolites found in this study may serve as the biomarkers of HLB in its early stage, and the metabolite signature of CLas infection may provide useful information for developing a potential treatment strategy.

  14. Metabolite Profiles of Lactic Acid Bacteria in Grass Silage▿

    OpenAIRE

    Broberg, Anders; Jacobsson, Karin; Ström, Katrin; Schnürer, Johan

    2007-01-01

    The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydro...

  15. Adiabatic and non-adiabatic charge pumping in a single-level molecular motor

    NARCIS (Netherlands)

    Napitu, B.D.; Thijssen, J.M.

    2015-01-01

    We propose a design for realizing quantum charge pump based on a recent proposal for a molecular motor (Seldenthuis J S et al 2010 ACS Nano 4 6681). Our design is based on the presence of a moiety with a permanent dipole moment which can rotate, thereby modulating the couplings to metallic contacts

  16. Multi-slice echo-planar spectroscopic MR imaging provides both global and local metabolite measures in multiple sclerosis

    DEFF Research Database (Denmark)

    Mathiesen, Henrik Kahr; Tscherning, Thomas; Sorensen, Per Soelberg

    2005-01-01

    MR spectroscopy (MRS) provides information about neuronal loss or dysfunction by measuring decreases in N-acetyl aspartate (NAA), a metabolite widely believed to be a marker of neuronal viability. In multiple sclerosis (MS), whole-brain NAA (WBNAA) has been suggested as a marker of disease...... progression and treatment efficacy in treatment trials, and the ability to measure NAA loss in specific brain regions early in the evolution of this disease may have prognostic value. Most spectroscopic studies to date have been limited to single voxels or nonlocalized measurements of WBNAA only......, measurements of metabolites in specific brain areas chosen after image acquisition (e.g., normal-appearing white matter (NAWM), gray matter (GM), and lesions) can be obtained. The identification and exclusion of regions that are inadequate for spectroscopic evaluation in global assessments can significantly...

  17. Systematics of nuclear RMS charge radii

    International Nuclear Information System (INIS)

    Brown, B.A.; Bronk, C.; Hodgson, P.E.

    1984-01-01

    The experimental RMS charge radii of isotopic sequences of nuclei are compared with calculations based on the spherical droplet model and spherical single-particle potential models. Harmonic-oscillator, Woods-Saxon and Skyrme Hartree-Fock single-particle potentials are considered. Deviations between experiment and theory are discussed in terms of the model parameters and in terms of the fundamental inadequacies of the models. The experimental B(E2) values connecting the ground states to the lowest 2 + states are used to estimate the increase in RMS radius due to the effects of deformation and zero-point vibrational motion. (author)

  18. Gut Microbiota-Regulated Pharmacokinetics of Berberine and Active Metabolites in Beagle Dogs After Oral Administration.

    Science.gov (United States)

    Feng, Ru; Zhao, Zhen-Xiong; Ma, Shu-Rong; Guo, Fang; Wang, Yan; Jiang, Jian-Dong

    2018-01-01

    Berberine (BBR) is considered a multi-target drug that has significant advantages. In contrast to its significant pharmacological effects in clinic, the plasma level of BBR is very low. Our previous work revealed that dihydroberberine (dhBBR) could be an absorbable form of BBR in the intestine, and butyrate is an active metabolite that is generated by gut bacteria in rats. In this study, for the first time we describe gut microbiota-regulated pharmacokinetics in beagle dogs after oral administration of BBR by single (50 mg/kg) or multiple doses (50 mg/kg/d) for 7 days. GC-MS, GC, LC-MS/MS, and LC/MS n -IT-TOF were used to detect dhBBR, butyrate and BBR as well as its Phase I and II metabolites, respectively. The results showed that dhBBR was not detected in dog plasma but was excreted in small amounts in the feces of dogs examined on days 3 and 7. Butyrate was generated by gut bacteria and increased by 1.3- and 1.2-fold in plasma or feces, respectively, after 7 days of BBR treatment compared to the levels before treatment. Changes of intestinal bacterial composition were analyzed by 16S rRNA genes analysis. The results presented that dogs treated with BBR for 7 days increased both the abundance of the butyrate- and the nitroreductases- producing bacteria. We also identified chemical structures of the Phase I and II metabolites and analyzed their contents in beagle dogs. Eleven metabolites were detected in plasma and feces after BBR oral administration (50 mg/kg) to dogs, including 8 metabolites of Phase I and III metabolites of Phase II. The pharmacokinetic profile indicated that the concentration of BBR in plasma was low, with a C max value of 36.88 ± 23.45 ng/mL. The relative content of glucuronic acid conjugates (M11) was higher than those of other metabolites (M1, M2, M12, and M14) in plasma. BBR was detected in feces, with high excreted amounts on day 3 (2625.04 ± 1726.94 μg/g) and day 7 (2793.43 ± 488.10 μg/g). In summary, this is the first study to

  19. Electrical discharge occurring between a negatively charged particle cloud and a grounded sphere electrode

    International Nuclear Information System (INIS)

    Higashiyama, Y; Migita, S; Toki, K; Sugimoto, T

    2008-01-01

    Electrostatic discharge occurring between a space-charge cloud and a grounded object was investigated using a large-scale charged particle cloud formed by using three set of cloud generators consisting of a blower and corona charger. The ejecting velocity of the particles affects the formation of the charged cloud. At the lower velocity, the charged cloud spread due to electrostatic repulsion force, while at the higher velocity cloud forms an elongated conical shape. To cause electrostatic discharge between the cloud and a grounded object, a grounded sphere electrode with 100 mm in diameter was set at the inside or outside of the cloud. The brush-like discharge channels reached the maximum length of 0.55 m. The discharge current has a waveform with single or multi-peak, a current peak of several amperes, the maximum charge quantity of 2 μC, and the duration of several microseconds. The relationship between the charge quantity and the current peak or the duration in each discharge was examined. The discharge between the cloud and the electrode placed at the outside of the cloud has relatively longer channels and multi-peak current with the longer duration, while that at the inside of the cloud has the lower charge quantity with single peak.

  20. DIFFICULTY OF MODE OF ACTION DETERMINATION FOR TRICHLOROETHYLENE: AN EXAMPLE OF COMPLEX INTERACTIONS OF METABOLITES AND OTHER CHEMICAL EXPOSURES (Journal Article)

    Science.gov (United States)

    The mode(s) of action (MOA) of a pollutant for adverse health effects may be dependent on the mixture of metabolites resulting from exposure to a single agent and may also be affected by co-exposure to pollutants that have similar targets or affected pathways. Trichloroethylene ...