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Ruiz-Martín MD, Qureshi N, González MA, Ollivier J, Frick B, Farago B. Influence of water on the microscopic dynamics of 1-butyl-3-methylimidazolium tetrafluoroborate studied by means of quasielastic neutron scattering. J Chem Phys 2022; 156:084505. [DOI: 10.1063/5.0082088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a systematic study on the effect of water on the microscopic dynamics of 1-butyl-3-methylimidazolium tetrafluoroborate by means of quasielastic neutron scattering. By mixing the ionic liquid with either heavy or light water, the different contributions to the quasielastic broadening could be identified and treated separately. This study was performed at room temperature, which is more than 15 °C above the demixing line. Our results show that even small amounts of water accelerate the diffusion mechanisms considerably. While samples with small water percentage reveal a diffusion process confined within ionic liquid nanodomains, an admixture of more than 15 wt. % water relieves the confinement. Furthermore, the presence of two water species was identified: one behaving as free water, whereas the other was interpreted as a component bound to the ionic liquid motion. Based on the fact that water preferentially binds to the BF4 anion, which itself has a negligible contribution to the scattered intensity, our experiments reveal unprecedented information about the microscopic anion dynamics.
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Affiliation(s)
- M. D. Ruiz-Martín
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - N. Qureshi
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - M. A. González
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - J. Ollivier
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - B. Frick
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
| | - B. Farago
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, France
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2
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Dietz J, Spengler U, Müllhaupt B, Schulze Zur Wiesch J, Piecha F, Mauss S, Seegers B, Hinrichsen H, Antoni C, Wietzke-Braun P, Peiffer KH, Berger A, Matschenz K, Buggisch P, Backhus J, Zizer E, Boettler T, Neumann-Haefelin C, Semela D, Stauber R, Berg T, Berg C, Zeuzem S, Vermehren J, Sarrazin C, Giostra E, Berning M, Hampe J, De Gottardi A, Rauch A, Semmo N, Discher T, Trauth J, Fischer J, Gress M, Günther R, Heinzow H, Schmidt J, Herrmann A, Stallmach A, Hilgard G, Deterding K, Lange C, Ciesek S, Wedemeyer H, Hoffmann D, Klinker H, Schulze P, Kocheise F, Müller-Schilling M, Kodal A, Kremer A, Ganslmayer M, Siebler J, Lammert F, Rissland J, Löbermann M, Götze T, Canbay A, Lohse A, von Felden J, Jordan S, Maieron A, Moradpour D, Chave JP, Moreno C, Müller T, Muche M, Epple HJ, Port K, von Hahn T, Cornberg M, Manns M, Reinhardt L, Ellenrieder V, Rockstroh J, Schattenberg J, Sprinzl M, Galle P, Roeb E, Steckstor M, Schmiegel W, Brockmeyer N, Seufferlein T, Stremmel W, Strey B, Thimme R, Teufel A, Vogelmann R, Ebert M, Tomasiewicz K, Trautwein C, Tacke F, Koenen T, Weber T, Zachoval R, Mayerle J, Raziorrouh B, Angeli W, Beckebaum S, Doberauer C, Durmashkina E, Hackelsberger A, Erhardt A, Garrido-Lüneburg A, Gattringer H, Genné D, Gschwantler M, Gundling F, Hametner S, Schöfl R, Hartmann C, Heyer T, Hirschi C, Jussios A, Kanzler S, Kordecki N, Kraus M, Kullig U, Wollschläger S, Magenta L, Beretta-Piccoli BT, Menges M, Mohr L, Muehlenberg K, Niederau C, Paulweber B, Petrides A, Pinkernell M, Piso R, Rambach W, Reiser M, Riecken B, Rieke A, Roth J, Schelling M, Schlee P, Schneider A, Scholz D, Schott E, Schuchmann M, Schulten-Baumer U, Seelhoff A, Stich A, Stickel F, Ungemach J, Walter E, Weber A, Winzer T, Abels W, Adler M, Audebert F, Baermann C, Bästlein E, Barth R, Barthel K, Becker W, Behrends J, Benninger J, Berger F, Berzow D, Beyer T, Bierbaum M, Blaukat O, Bodtländer A, Böhm G, Börner N, Bohr U, Bokemeyer B, Bruch H, Bucholz D, Burkhard O, Busch N, Chirca C, Delker R, Diedrich J, Frank M, Diehl M, Dienethal A, Dietel P, Dikopoulos N, Dreck M, Dreher F, Drude L, Ende K, Ehrle U, Baumgartl K, Emke F, Glosemeyer R, Felten G, Hüppe D, Fischer J, Fischer U, Frederking D, Frick B, Friese G, Gantke B, Geyer P, Schwind H, Glas M, Glaunsinger T, Goebel F, Göbel U, Görlitz B, Graf R, Gruber H, Härter G, Herder M, Heuchel T, Heuer S, Höffl KH, Hörster H, Sonne JU, Hofmann W, Holst F, Hunstiger M, Hurst A, Jägel-Guedes E, John C, Jung M, Kallinowski B, Kapzan B, Kerzel W, Khaykin P, Klarhof M, Klüppelberg U, Klugewitz K, Knapp B, Knevels U, Kochsiek T, Körfer A, Köster A, Kuhn M, Langekamp A, Künzig B, Link R, Littman M, Löhr H, Lutz T, Knecht G, Lutz U, Mainz D, Mahle I, Maurer P, Mayer C, Meister V, Möller H, Heyne R, Moritzen D, Mroß M, Mundlos M, Naumann U, Nehls O, Ningel K, Oelmann A, Olejnik H, Gadow K, Pascher E, Petersen J, Philipp A, Pichler M, Polzien F, Raddant R, Riedel M, Rietzler S, Rössle M, Rufle W, Rump A, Schewe C, Hoffmann C, Schleehauf D, Schmidt K, Schmidt W, Schmidt-Heinevetter G, Schmidtler-von Fabris J, Schnaitmann E, Schneider L, Schober A, Niehaus-Hahn S, Schwenzer J, Seidel T, Seitel G, Sick C, Simon K, Stähler D, Stenschke F, Steffens H, Stein K, Steinmüller M, Sternfeld T, Strey B, Svensson K, Tacke W, Teuber G, Teubner K, Thieringer J, Tomesch A, Trappe U, Ullrich J, Urban G, Usadel S, von Lucadou A, Weinberger F, Werheid-Dobers M, Werner P, Winter T, Zehnter E, Zipf A. Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections. Clin Gastroenterol Hepatol 2021; 19:195-198.e2. [PMID: 31706062 DOI: 10.1016/j.cgh.2019.10.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/19/2019] [Accepted: 10/25/2019] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.8 However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.
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Affiliation(s)
- Julia Dietz
- Department of Internal Medicine 1, University Hospital Frankfurt, Goethe University, Frankfurt, and German Center for Infection Research (DZIF), External Partner Site, Frankfurt, Germany
| | - Ulrich Spengler
- Department of Internal Medicine I, University of Bonn, Bonn, and German Center for Infection Research (DZIF), Partner Site, Cologne-Bonn, Germany
| | - Beat Müllhaupt
- Swiss Hepato-Pancreato-Biliary Center and Department of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Julian Schulze Zur Wiesch
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, and German Center for Infection Research (DZIF), Partner Site, Hamburg-Lübeck-Borstel-Riems, Germany
| | - Felix Piecha
- I. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, and German Center for Infection Research (DZIF), Partner Site, Hamburg-Lübeck-Borstel-Riems, Germany
| | - Stefan Mauss
- Center for HIV and Hepatogastroenterology, Düsseldorf, Germany
| | - Barbara Seegers
- Gastroenterologisch-Hepatologisches Zentrum Kiel, Kiel, Germany
| | | | - Christoph Antoni
- Department of Internal Medicine II, University Hospital Mannheim, Mannheim, Germany
| | | | - Kai-Henrik Peiffer
- Department of Internal Medicine 1, University Hospital Frankfurt, Goethe University, Frankfurt, and German Center for Infection Research (DZIF), External Partner Site, Frankfurt, Germany
| | - Annemarie Berger
- Institute for Medical Virology, University Hospital Frankfurt, Frankfurt, Germany
| | | | - Peter Buggisch
- Institute for Interdisciplinary Medicine IFI, Hamburg, Germany
| | - Johanna Backhus
- Department of Internal Medicine I, Ulm University, Ulm, Germany
| | - Eugen Zizer
- Department of Internal Medicine I, Ulm University, Ulm, Germany
| | - Tobias Boettler
- Department of Medicine II, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christoph Neumann-Haefelin
- Department of Medicine II, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - David Semela
- Division of Gastroenterology and Hepatology, Kantonsspital St Gallen, St Gallen, Switzerland
| | - Rudolf Stauber
- Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Thomas Berg
- Department of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany
| | - Christoph Berg
- Department of Internal Medicine I, University of Tübingen, Tübingen, Germany
| | - Stefan Zeuzem
- Department of Internal Medicine 1, University Hospital Frankfurt, Goethe University, Frankfurt, and German Center for Infection Research (DZIF), External Partner Site, Frankfurt, Germany
| | - Johannes Vermehren
- Department of Internal Medicine 1, University Hospital Frankfurt, Goethe University, Frankfurt, and German Center for Infection Research (DZIF), External Partner Site, Frankfurt, Germany
| | - Christoph Sarrazin
- Department of Internal Medicine 1, University Hospital Frankfurt, Goethe University, Frankfurt, and German Center for Infection Research (DZIF), External Partner Site, Frankfurt, Germany; Medizinische Klinik 2, St Josefs-Hospital, Wiesbaden, Germany.
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Russo D, De Angelis A, Paciaroni A, Frick B, de Sousa N, Wurm FR, Teixeira J. Protein-Polymer Dynamics as Affected by Polymer Coating and Interactions. Langmuir 2019; 35:2674-2679. [PMID: 30677298 DOI: 10.1021/acs.langmuir.8b03636] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigate the relaxation dynamics of protein-polymer conjugates by neutron scattering spectroscopy to understand to which extent the coating of a protein by a polymer can replace water in promoting thermal structural fluctuations. For this purpose, we compare the dynamics of protein-polymer mixtures to that of conjugates with a variable number of polymers covalently attached to the protein. Results show that the flexibility of the protein is larger in protein-polymer mixtures than in native protein or in conjugates, even in the dry state. Upon hydration, both the native protein and the conjugate show equivalent dynamics, suggesting that the polymer grafted on the protein surface adsorbs all water molecules.
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Affiliation(s)
- D Russo
- Consiglio Nazionale delle Ricerche & Istituto Officina dei Materiali c/o Institut Laue Langevin , 38042 Grenoble , France
- Australian Nuclear Science and Technology Organisation , New Illawarra Road, Lucas Heights , NSW 2234 , Australia
| | - A De Angelis
- Dipartimento di Fisica e Geologia , Università degli Studi di Perugia and CNISM , Via Pascoli, 06123 Perugia , Italy
| | - A Paciaroni
- Dipartimento di Fisica e Geologia , Università degli Studi di Perugia and CNISM , Via Pascoli, 06123 Perugia , Italy
| | - B Frick
- Institut Laue-Langevin , 38042 Grenoble , France
| | - N de Sousa
- Australian Nuclear Science and Technology Organisation , New Illawarra Road, Lucas Heights , NSW 2234 , Australia
| | - F R Wurm
- Max-Planck-Institut für Polymerforschung , Ackermannweg 10 , 55128 Mainz , Germany
| | - J Teixeira
- Laboratoire Léon Brillouin (CEA/CNRS), CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
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4
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Hansen HW, Sanz A, Adrjanowicz K, Frick B, Niss K. Evidence of a one-dimensional thermodynamic phase diagram for simple glass-formers. Nat Commun 2018; 9:518. [PMID: 29410398 PMCID: PMC5802781 DOI: 10.1038/s41467-017-02324-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/20/2017] [Indexed: 11/09/2022] Open
Abstract
Glass formers show motional processes over an extremely broad range of timescales, covering more than ten orders of magnitude, meaning that a full understanding of the glass transition needs to comprise this tremendous range in timescales. Here we report simultaneous dielectric and neutron spectroscopy investigations of three glass-forming liquids, probing in a single experiment the full range of dynamics. For two van der Waals liquids, we locate in the pressure-temperature phase diagram lines of identical dynamics of the molecules on both second and picosecond timescales. This confirms predictions of the isomorph theory and effectively reduces the phase diagram from two to one dimension. The implication is that dynamics on widely different timescales are governed by the same underlying mechanisms.
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Affiliation(s)
- H W Hansen
- Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, Postbox 260, DK-4000, Roskilde, Denmark
| | - A Sanz
- Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, Postbox 260, DK-4000, Roskilde, Denmark
| | - K Adrjanowicz
- Institute of Physics, University of Silesia, ul. Uniwersytecka 4, 40-007, Katowice, Poland
| | - B Frick
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble Cedex 9, France
| | - K Niss
- Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University, Postbox 260, DK-4000, Roskilde, Denmark.
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Andersson CD, Martinez N, Zeller D, Rondahl SH, Koza MM, Frick B, Ekström F, Peters J, Linusson A. Changes in dynamics of α-chymotrypsin due to covalent inhibitors investigated by elastic incoherent neutron scattering. Phys Chem Chem Phys 2017; 19:25369-25379. [DOI: 10.1039/c7cp04041e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamics of chymotrypsin increases when bound to two different covalent inhibitors. These effects were analyzed by univariate and multivariate methods.
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Affiliation(s)
| | - N. Martinez
- Institut Laue Langevin
- F-38042 Grenoble Cedex 9
- France
- Univ. Grenoble Alpes
- IBS and LiPhy
| | - D. Zeller
- Institut Laue Langevin
- F-38042 Grenoble Cedex 9
- France
- Univ. Grenoble Alpes
- IBS and LiPhy
| | - S. H. Rondahl
- CBRN Defence and Security
- Swedish Defence Research Agency
- SE-90621 Umeå
- Sweden
| | - M. M. Koza
- Institut Laue Langevin
- F-38042 Grenoble Cedex 9
- France
| | - B. Frick
- Institut Laue Langevin
- F-38042 Grenoble Cedex 9
- France
| | - F. Ekström
- CBRN Defence and Security
- Swedish Defence Research Agency
- SE-90621 Umeå
- Sweden
| | - J. Peters
- Institut Laue Langevin
- F-38042 Grenoble Cedex 9
- France
- Univ. Grenoble Alpes
- IBS and LiPhy
| | - A. Linusson
- Department of Chemistry
- Umeå University
- SE-90187 Umeå
- Sweden
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6
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Arbe A, Malo de Molina P, Alvarez F, Frick B, Colmenero J. Dielectric Susceptibility of Liquid Water: Microscopic Insights from Coherent and Incoherent Neutron Scattering. Phys Rev Lett 2016; 117:185501. [PMID: 27834987 DOI: 10.1103/physrevlett.117.185501] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Indexed: 06/06/2023]
Abstract
The analysis of neutron scattering results on H dynamics (H_{2}O) and the dynamic structure factor (D_{2}O) around the intermolecular peak and at intermediate length scales in terms of the susceptibilities reveals three processes (diffusive, local relaxational and vibrational) at frequencies below 3 THz, to which the contributions commonly invoked in dielectric studies can be directly mapped. We achieve a unified description of the results from both techniques, clarifying the nature of the molecular motions involved in the dielectric spectra and their impact on the structural relaxation.
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Affiliation(s)
- A Arbe
- Centro de Física de Materiales (CFM) (CSIC-UPV/EHU)-Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - P Malo de Molina
- Centro de Física de Materiales (CFM) (CSIC-UPV/EHU)-Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - F Alvarez
- Centro de Física de Materiales (CFM) (CSIC-UPV/EHU)-Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
| | - B Frick
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS 20156, F-38042 Grenoble Cedex 9, France
| | - J Colmenero
- Centro de Física de Materiales (CFM) (CSIC-UPV/EHU)-Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
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Ondrejkovic P, Kempa M, Kulda J, Frick B, Appel M, Combet J, Dec J, Lukasiewicz T, Hlinka J. Dynamics of nanoscale polarization fluctuations in a uniaxial relaxor. Phys Rev Lett 2014; 113:167601. [PMID: 25361280 DOI: 10.1103/physrevlett.113.167601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Indexed: 06/04/2023]
Abstract
We have studied neutron diffuse scattering in a Sr(0.61)Ba(0.39)Nb(2)O(6) single crystal by neutron backscattering at sub-μeV energy resolution. We can identify two response components with transverse polarization: an elastic (resolution limited) central peak, which monotonically increases with decreasing temperature, and a quasielastic central peak, having a maximum intensity around the ferroelectric phase transition close to 350 K. In contrast to previous neutron experiments on this and other relaxor materials, we were able to observe a temperature dependence of the characteristic frequency of these fluctuations, obeying the same Vogel-Fulcher law as the dynamic part of the dielectric permittivity of this material. In this way our findings provide a first direct link between the Vogel-Fulcher-type frequency dependence of dielectric permittivity and dynamic nanoscale lattice modulations with a transverse correlation length of about 5-10 unit cells.
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Affiliation(s)
- P Ondrejkovic
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8, Czech Republic
| | - M Kempa
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8, Czech Republic
| | - J Kulda
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - B Frick
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - M Appel
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J Combet
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J Dec
- Institute of Materials Science, University of Silesia, Bankowa 12, PL-40-007 Katowice, Poland
| | - T Lukasiewicz
- Institute of Electronic Materials Technology, 133 Wolczynska Street, 01-919 Warsaw, Poland
| | - J Hlinka
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8, Czech Republic
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Palm U, Frick B, Lustig D, Nitsche M, Kuo MF, Padberg F. P 103. Transcranial direct current stimulation reveals reduced LTP-like motor cortex plasticity in depression: A study in antidepressant-free patients. Clin Neurophysiol 2013. [DOI: 10.1016/j.clinph.2013.04.181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Serrano-Ruiz D, Alonso-Cristobal P, Laurenti M, Frick B, López-Cabarcos E, Rubio-Retama J. Influence of the inter-chain hydrogen bonds on the thermoresponsive swelling behavior of UCST-like microgels. POLYMER 2013. [DOI: 10.1016/j.polymer.2013.06.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Fotiadou S, Karageorgaki C, Chrissopoulou K, Karatasos K, Tanis I, Tragoudaras D, Frick B, Anastasiadis SH. Structure and Dynamics of Hyperbranched Polymer/Layered Silicate Nanocomposites. Macromolecules 2013. [DOI: 10.1021/ma302405q] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. Fotiadou
- Institute of Electronic Structure
and Laser, Foundation for Research and Technology—Hellas, P.O. Box 1527, 711 10 Heraklion, Crete, Greece
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 541 24 Thessaloniki,
Greece
| | - C. Karageorgaki
- Institute of Electronic Structure
and Laser, Foundation for Research and Technology—Hellas, P.O. Box 1527, 711 10 Heraklion, Crete, Greece
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 541 24 Thessaloniki,
Greece
| | - K. Chrissopoulou
- Institute of Electronic Structure
and Laser, Foundation for Research and Technology—Hellas, P.O. Box 1527, 711 10 Heraklion, Crete, Greece
| | - K. Karatasos
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 541 24 Thessaloniki,
Greece
| | - I. Tanis
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 541 24 Thessaloniki,
Greece
| | - D. Tragoudaras
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 541 24 Thessaloniki,
Greece
| | - B. Frick
- Institut Laue Langevin (ILL), 6 rue Jules Horowitz, F38042 Grenoble, France
| | - S. H. Anastasiadis
- Institute of Electronic Structure
and Laser, Foundation for Research and Technology—Hellas, P.O. Box 1527, 711 10 Heraklion, Crete, Greece
- Department of Chemistry, University of Crete, P.O. Box 2208, 710 03 Heraklion
Crete, Greece
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Gerstl C, Schneider GJ, Fuxman A, Zamponi M, Frick B, Seydel T, Koza M, Genix AC, Allgaier J, Richter D, Colmenero J, Arbe A. Quasielastic Neutron Scattering Study on the Dynamics of Poly(alkylene oxide)s. Macromolecules 2012. [DOI: 10.1021/ma3003399] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. Gerstl
- Jülich Centre
for Neutron Science (JCNS 1) and Institut for Complex Systems (ICS
1), Forschungszentrum Jülich GmbH, D−52425 Jülich, Germany
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - G. J. Schneider
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - A. Fuxman
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - M. Zamponi
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - B. Frick
- Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - T. Seydel
- Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - M. Koza
- Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - A.-C. Genix
- Laboratoire Charles Coulomb, UMR 5221, CNRS and Université Montpellier 2, 34095 Montpellier,
France
| | - J. Allgaier
- Jülich Centre
for Neutron Science (JCNS 1) and Institut for Complex Systems (ICS
1), Forschungszentrum Jülich GmbH, D−52425 Jülich, Germany
| | - D. Richter
- Jülich Centre
for Neutron Science (JCNS 1) and Institut for Complex Systems (ICS
1), Forschungszentrum Jülich GmbH, D−52425 Jülich, Germany
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - J. Colmenero
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, E-20018 San
Sebastián, Spain
- Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián,
Spain
| | - A. Arbe
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, E-20018 San
Sebastián, Spain
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Abstract
We have combined incoherent quasielastic neutron scattering experiments and atomistic molecular simulations to investigate the microscopic dynamics of glycerol moving away from the hydrodynamic limit. We relate changes in the momentum transfer (Q) dependence of the relaxation time to distinct changes of the single-particle dynamics. Going from small to large values of Q, a first crossover at about 0.5 Å(-1) is related to the coupling of the translational diffusion dynamics to the non-Debye structural relaxation, while the second crossover at a Q-value near the main diffraction peak is associated with the Gaussian to non-Gaussian crossover of the short-time molecular dynamics, related to the decaging processes. We offer an unprecedented extension of previous studies on polymeric systems towards the case of the typical low-molecular-weight glass-forming system glycerol.
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Affiliation(s)
- R Busselez
- Institute of Physics of Rennes, CNRS-University of Rennes 1, UMR 6251, F-35042 Rennes, France
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13
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Capponi S, Arbe A, Cerveny S, Busselez R, Frick B, Embs JP, Colmenero J. Quasielastic neutron scattering study of hydrogen motions in an aqueous poly(vinyl methyl ether) solution. J Chem Phys 2011; 134:204906. [PMID: 21639476 DOI: 10.1063/1.3592560] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a quasielastic neutron scattering (QENS) investigation of the component dynamics in an aqueous Poly(vinyl methyl ether) (PVME) solution (30% water content in weight). In the glassy state, an important shift in the Boson peak of PVME is found upon hydration. At higher temperatures, the diffusive-like motions of the components take place with very different characteristic times, revealing a strong dynamic asymmetry that increases with decreasing T. For both components, we observe stretching of the scattering functions with respect to those in the bulk and non-Gaussian behavior in the whole momentum transfer range investigated. To explain these observations we invoke a distribution of mobilities for both components, probably originated from structural heterogeneities. The diffusive-like motion of PVME in solution takes place faster and apparently in a more continuous way than in bulk. We find that the T-dependence of the characteristic relaxation time of water changes at T ≲ 225 K, near the temperature where a crossover from a low temperature Arrhenius to a high temperature cooperative behavior has been observed by broadband dielectric spectroscopy (BDS) [S. Cerveny, J. Colmenero and A. Alegría, Macromolecules, 38, 7056 (2005)]. This observation might be a signature of the onset of confined dynamics of water due to the freezing of the PVME dynamics, that has been selectively followed by these QENS experiments. On the other hand, revisiting the BDS results on this system we could identify an additional "fast" process that can be attributed to water motions coupled with PVME local relaxations that could strongly affect the QENS results. Both kinds of interpretations, confinement effects due to the increasing dynamic asymmetry and influence of localized motions, could provide alternative scenarios to the invoked "strong-to-fragile" transition.
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Affiliation(s)
- S Capponi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain.
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Affiliation(s)
- S. Arrese-Igor
- Centro de Física de Materiales (CSIC−UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - A. Arbe
- Centro de Física de Materiales (CSIC−UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - B. Frick
- Institut Laue−Langevin, BP 156X, 38042 Grenoble Cedex 9, France
| | - J. Colmenero
- Centro de Física de Materiales (CSIC−UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Departamento de Física de Materiales UPV/EHU, Paseo Manuel de Lardizabal 3, 20018 San Sebastián, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
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16
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Rubio-Retama J, Zafeiropoulos NE, Frick B, Seydel T, López-Cabarcos E. Investigation of the relationship between hydrogen bonds and macroscopic properties in hybrid core-shell gamma-Fe2O3-P(NIPAM-AAS) microgels. Langmuir 2010; 26:7101-7106. [PMID: 20143864 DOI: 10.1021/la904452c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We investigate in a hybrid material the interactions existing between magnetic nanoparticles of gamma-Fe(2)O(3) and the polymer matrix constituted by core-shell poly(N-isopropylacrylamide-sodium acrylate) microgels. These interactions provoke the shifting of the microgel volume phase transition to higher temperatures when the amount of gamma-Fe(2)O(3) increases. The study was performed using different techniques such as incoherent quasi-elastic neutron scattering (IQNS), infrared spectroscopy (FTIR-ATR), and dynamic light scattering (DLS). Below the low critical solution temperature (LCST) of the polymer, the IQNS data confirm that the presence of inorganic nanoparticles affects the PNIPAM chain motions. Thus, in the swollen state both the mean-square displacement of the polymer segments and the diffusive motion of the polymer chains decrease as the iron oxide content increases. The FTIR-ATR study indicates that the reduction of vibrational and diffusional motions of the polymer chains is due to the formation of hydrogen bonds between the amide groups of the polymer matrix and the OH groups of the magnetic nanoparticles. The creation of this hybrid complex would explain the reduction of the swelling capacity with increasing the iron content in the microgels. Furthermore, this interaction could also explain the shift of the polymer LCST to higher temperatures as due to the extra energy required by the system to break the hydrogen bonds prior to the PNIPAM collapse.
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Affiliation(s)
- J Rubio-Retama
- Departamento Química Física II, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain
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Richter D, Zorn R, Frick B, Farago B. Neutron Scattering Experiments in the Neighborhood of the Glass Transition in Polybutadiene - a Test of Mode Coupling. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19910950931] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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18
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Fotiadou S, Chrissopoulou K, Frick B, Anastasiadis SH. Structure and dynamics of polymer chains in hydrophilic nanocomposites. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/polb.21974] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Capponi S, Arbe A, Alvarez F, Colmenero J, Frick B, Embs JP. Atomic motions in poly(vinyl methyl ether): A combined study by quasielastic neutron scattering and molecular dynamics simulations in the light of the mode coupling theory. J Chem Phys 2009; 131:204901. [DOI: 10.1063/1.3258857] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Dalle-Ferrier C, Simon S, Zheng W, Badrinarayanan P, Fennell T, Frick B, Zanotti JM, Alba-Simionesco C. Consequence of excess configurational entropy on fragility: the case of a polymer-oligomer blend. Phys Rev Lett 2009; 103:185702. [PMID: 19905814 DOI: 10.1103/physrevlett.103.185702] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Indexed: 05/28/2023]
Abstract
By taking advantage of the molecular weight dependence of the glass transition of polymers and their ability to form perfectly miscible blends, we propose a way to modify the fragility of a system, from fragile to strong, keeping the same glass properties, i.e., vibrational density of states, mean-square displacement, and local structure. Both slow and fast dynamics are investigated by calorimetry and neutron scattering in an athermal polystyrene-oligomer blend, and compared to those of a pure 17-mer polystyrene considered to be a reference, of the same Tg. Whereas the blend and the pure 17-mer have the same heat capacity in the glass and in the liquid, their fragilities differ strongly. Thus, the difference in fragility is related to an extra configurational entropy created by the mixing process and acting at a scale much larger than the interchain distance, without affecting the fast dynamics and the structure of the glass.
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Affiliation(s)
- C Dalle-Ferrier
- Laboratoire de Chimie Physique, UMR 8000, Bâtiment 349, Université, Paris-Sud, 91405 Orsay, France
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Laurenti M, López-Cabarcos E, García-Blanco F, Frick B, Rubio-Retama J. Interpenetrated PNIPAM-polythiophene microgels for nitro aromatic compound detection. Langmuir 2009; 25:9579-9584. [PMID: 19456092 DOI: 10.1021/la900864a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this work, we present a facile and reproducible method to obtain thermally responsive, monodisperse, fluorescent microgels with diameters smaller than 700 nm based on poly(N-isopropyl acrylamide) (PNIPAM) interpenetrated with poly(thiophene-ethyl buthyl sulfonate) (PTEBS). Changing the temperature and inducing the microgel volume phase transition, it is possible to modify the photoluminescence (PL) properties of the microgels. Thus, when the temperature was below the low critical solution temperature (LCST) of PNIPAM, the PL intensity was higher than that above the LCST. Time-resolved fluorescence measurements indicate that, in the swollen state, the increment of cross-linking increases the fluorescence decay time of PTEBS. By contrast, in the collapsed state, variations in the decay time were attributed to higher rigidity of the PNIPAM-PTEBS system, which was confirmed by neutron scattering measurements. Moreover, the shift in the wavelength of the fluorescence emission peak observed above the LCST indicates that the collapsed PNIPAM matrix was able to interact with the PTEBS chains hindering the formation of pi-pi interactions. This property is envisaged for developing a picric acid microsensor based on the formation of pi-pi interactions with the pi-conjugated polymer, thus quenching its PL emission. Above the LCST of PNIPAM-PTEBS microgels, the interactions would be broken and the initial PL emission would be recovered. This property could render reusable microsensors for detection of nitro aromatic compounds.
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Affiliation(s)
- M Laurenti
- Physical Chemistry Department, Faculty of Pharmacy, Complutense University, Madrid 28040, Spain
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Busselez R, Lefort R, Guendouz M, Frick B, Merdrignac-Conanec O, Morineau D. Molecular dynamics of glycerol and glycerol-trehalose bioprotectant solutions nanoconfined in porous silicon. J Chem Phys 2009; 130:214502. [DOI: 10.1063/1.3147222] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Chatterji T, Schneider GJ, van Eijck L, Frick B, Bhattacharya D. Direct evidence for the Nd magnetic ordering in NdMnO(3) from the hyperfine field splitting of Nd nuclear levels. J Phys Condens Matter 2009; 21:126003. [PMID: 21817475 DOI: 10.1088/0953-8984/21/12/126003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We investigated the low energy excitations in NdMnO(3) in the µeV range by a backscattering neutron spectrometer. The energy spectra on polycrystalline NdMnO(3) samples revealed inelastic peaks at E = 2.15 ± 0.01 µeV at T = 2 K on both energy gain and energy loss sides. The inelastic peaks move gradually towards lower energy with increasing temperature and tend to merge with the elastic peak at the electronic magnetic ordering temperature of Nd, T(Nd)≈20 K. However, at temperatures higher than T(Nd)≈20 K the energy of the inelastic peak decreases at a much slower rate and remains finite up to T = 55 K, the highest temperature investigated. We interpret the inelastic peaks to be due to the transition between the hyperfine-split nuclear level of the (143)Nd and (145)Nd isotopes with spin I = 7/2 caused by the magnetic ordering of Nd electronic moment below T(Nd)≈20 K. We ascribe the finite energy of the inelastic peak and its much smaller temperature dependence at T>20 K to be due to the polarization of the Nd magnetic moment by the field of Mn moments that order below T(N)≈78 K.
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Affiliation(s)
- Tapan Chatterji
- JCNS, Forschungszentrum Jülich Outstation at Institut Laue-Langevin, BP 156, F-38042 Grenoble Cedex, France
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Brand RA, Hippert F, Frick B. Iron dynamics in Al-Cu-Fe quasicrystals and approximants: Mössbauer and neutron experiments. J Phys Condens Matter 2009; 21:045405. [PMID: 21715806 DOI: 10.1088/0953-8984/21/4/045405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present new results on the iron dynamics in the icosahedral quasicrystal i-AlCuFe and two cubic approximants as well as the non-approximant Al-Cu-Fe cubic B2 phase. Conventional Mössbauer spectroscopy is used as well as, for the i-AlCuFe phase, high Doppler velocity Mössbauer spectroscopy and quasielastic neutron scattering for samples with different Fe isotope contents. We show that in the i-phase the Fe Lamb-Mössbauer recoilless fraction decreases below that predicted for lattice vibrations alone for temperatures above about 550 K. This decrease is correlated with the onset of a quasielastic signal seen in both Mössbauer and neutron backscattering spectroscopy, which indicates the presence above 550 K of Fe jump processes confined in a local cage. The timescale of the Fe jumps (660 ps at 1000 K) and their temperature dependence differ widely from those of Cu jumps in the same i-AlCuFe quasicrystal. From the temperature dependence of the quadrupole splitting of the (57)Fe Mössbauer spectrum, one can distinguish two kinds of Fe jumps, one starting at 550 K and the second above 800 K. In the two cubic approximants, a loss in the Fe recoilless fraction also occurs above 550 K, revealing the same kind of Fe dynamics as in the i-phase but the effect is smaller. On the other hand, no anomalous Fe dynamics (other than lattice vibrations) is detected in the B2-AlCuFe phase. Since the cubic approximants possess similar local configurations as the quasicrystal, we conclude that locally a Penrose tile description is appropriate. This shows that the detected Fe jumps can be interpreted in terms of phason-like local tiling flips.
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Affiliation(s)
- R A Brand
- INT, Forschungszentrum Karlsruhe, D-76344 Eggenstein-Leopoldshafen, Germany. Department of Physics, Universität Dusburg-Essen, D-47048 Duisburg, Germany
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Teixeira SCM, Ankner J, Bellissent-Funel MC, Bewley R, Blakeley MP, Coates L, Dahint R, Dalgliesh R, Dencher N, Dhont J, Fischer P, Forsyth VT, Fragneto G, Frick B, Geue T, Gilles R, Gutberlet T, Haertlein M, Hauß T, Häußler W, Heller WT, Herwig K, Holderer O, Juranyi F, Kampmann R, Knott R, Kohlbrecher J, Kreuger S, Langan P, Lechner R, Lynn G, Majkrzak C, May R, Meilleur F, Mo Y, Mortensen K, Myles DAA, Natali F, Neylon C, Niimura N, Ollivier J, Ostermann A, Peters J, Pieper J, Rühm A, Schwahn D, Shibata K, Soper AK, Straessle T, Suzuki UI, Tanaka I, Tehei M, Timmins P, Torikai N, Unruh T, Urban V, Vavrin R, Weiss K, Zaccai G. New sources and instrumentation for neutrons in biology. Chem Phys 2009; 345:133-151. [PMID: 19132140 PMCID: PMC2614686 DOI: 10.1016/j.chemphys.2008.02.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Neutron radiation offers significant advantages for the study of biological molecular structure and dynamics. A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed.
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Affiliation(s)
- S C M Teixeira
- Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble cedex 9, France
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27
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Teixeira S, Zaccai G, Ankner J, Bellissent-Funel M, Bewley R, Blakeley M, Callow P, Coates L, Dahint R, Dalgliesh R, Dencher N, Forsyth V, Fragneto G, Frick B, Gilles R, Gutberlet T, Haertlein M, Hauß T, Häußler W, Heller W, Herwig K, Holderer O, Juranyi F, Kampmann R, Knott R, Krueger S, Langan P, Lechner R, Lynn G, Majkrzak C, May R, Meilleur F, Mo Y, Mortensen K, Myles D, Natali F, Neylon C, Niimura N, Ollivier J, Ostermann A, Peters J, Pieper J, Rühm A, Schwahn D, Shibata K, Soper A, Strässle T, Suzuki J, Tanaka I, Tehei M, Timmins P, Torikai N, Unruh T, Urban V, Vavrin R, Weiss K. Erratum to “New sources and instrumentation for neutrons in biology” [Chem. Phys. 345 (2008) 133–151]. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Rubio Retama J, Frick B, Seydel T, Stamm M, Fernandez Barbero A, López Cabarcos E. Polymer Chain Dynamics of Core−Shell Thermosensitive Microgels. Macromolecules 2008. [DOI: 10.1021/ma800668t] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Rubio Retama
- Department of Pharmaceutical Chemical-Physics, University Complutense of Madrid, 28040 Madrid, Spain, Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, Dresden 01069, Germany, Institut Laue Langevin, Grenoble, France, and Complex Fluid Physics Group, Department of Applied Physics, University of Almería, E-04120 Almería, Spain
| | - B. Frick
- Department of Pharmaceutical Chemical-Physics, University Complutense of Madrid, 28040 Madrid, Spain, Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, Dresden 01069, Germany, Institut Laue Langevin, Grenoble, France, and Complex Fluid Physics Group, Department of Applied Physics, University of Almería, E-04120 Almería, Spain
| | - T. Seydel
- Department of Pharmaceutical Chemical-Physics, University Complutense of Madrid, 28040 Madrid, Spain, Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, Dresden 01069, Germany, Institut Laue Langevin, Grenoble, France, and Complex Fluid Physics Group, Department of Applied Physics, University of Almería, E-04120 Almería, Spain
| | - M. Stamm
- Department of Pharmaceutical Chemical-Physics, University Complutense of Madrid, 28040 Madrid, Spain, Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, Dresden 01069, Germany, Institut Laue Langevin, Grenoble, France, and Complex Fluid Physics Group, Department of Applied Physics, University of Almería, E-04120 Almería, Spain
| | - A. Fernandez Barbero
- Department of Pharmaceutical Chemical-Physics, University Complutense of Madrid, 28040 Madrid, Spain, Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, Dresden 01069, Germany, Institut Laue Langevin, Grenoble, France, and Complex Fluid Physics Group, Department of Applied Physics, University of Almería, E-04120 Almería, Spain
| | - E. López Cabarcos
- Department of Pharmaceutical Chemical-Physics, University Complutense of Madrid, 28040 Madrid, Spain, Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, Dresden 01069, Germany, Institut Laue Langevin, Grenoble, France, and Complex Fluid Physics Group, Department of Applied Physics, University of Almería, E-04120 Almería, Spain
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Genix AC, Arbe A, Arrese-Igor S, Colmenero J, Richter D, Frick B, Deen PP. Neutron scattering investigation of a diluted blend of poly(ethylene oxide) in polyethersulfone. J Chem Phys 2008; 128:184901. [DOI: 10.1063/1.2918497] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Bordallo HN, Frick B, Schober H, Seydel T. Primary spectrometer neutron optics simulations for a new cold neutron backscattering spectrometer. J of Neutron Res 2008. [DOI: 10.1080/10238160802401344] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Chrissopoulou K, Anastasiadis SH, Giannelis EP, Frick B. Quasielastic neutron scattering of poly(methyl phenyl siloxane) in the bulk and under severe confinement. J Chem Phys 2007; 127:144910. [DOI: 10.1063/1.2775449] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Niss K, Begen B, Frick B, Ollivier J, Beraud A, Sokolov A, Novikov VN, Alba-Simionesco C. Influence of pressure on the boson peak: stronger than elastic medium transformation. Phys Rev Lett 2007; 99:055502. [PMID: 17930767 DOI: 10.1103/physrevlett.99.055502] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Indexed: 05/25/2023]
Abstract
We study the changes in the low-frequency vibrational dynamics of poly(isobutylene) under pressure up to 1.4 GPa, corresponding to a density change of 20%. Combining inelastic neutron, x-ray, and Brillouin light scattering, we analyze the variations in the boson peak, transverse and longitudinal sound velocities, and the Debye level under pressure. We find that the boson peak variation under pressure cannot be explained by the elastic continuum transformation only. Surprisingly, the shape of the boson peak remains unchanged even at such high compression.
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Affiliation(s)
- K Niss
- Laboratoire de Chimie Physique, UMR 8000, Université Paris Sud and CNRS, Bâtiment 349, 91405 Orsay, France
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Tyagi M, Arbe A, Alegría A, Colmenero J, Frick B. Dynamic Confinement Effects in Polymer Blends. A Quasielastic Neutron Scattering Study of the Slow Component in the Blend Poly(vinyl acetate)/Poly(ethylene oxide). Macromolecules 2007. [DOI: 10.1021/ma070539i] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. Tyagi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain, Centro de Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - A. Arbe
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain, Centro de Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - A. Alegría
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain, Centro de Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J. Colmenero
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain, Centro de Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - B. Frick
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain, Centro de Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
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Guégan R, Morineau D, Lefort R, Moréac A, Béziel W, Guendouz M, Zanotti JM, Frick B. Molecular dynamics of a short-range ordered smectic phase nanoconfined in porous silicon. J Chem Phys 2007; 126:064902. [PMID: 17313239 DOI: 10.1063/1.2435366] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
4-n-octyl-4-cyanobiphenyl has been recently shown to display an unusual sequence of phases when confined into porous silicon (PSi). The gradual increase of oriented short-range smectic (SRS) correlations in place of a phase transition has been interpreted as a consequence of the anisotropic quenched disorder induced by confinement in PSi. Combining two quasielastic neutron scattering experiments with complementary energy resolutions, the authors present the first investigation of the individual molecular dynamics of this system. A large reduction of the molecular dynamics is observed in the confined liquid phase, as a direct consequence of the boundary conditions imposed by the confinement. Temperature fixed window scans reveal a continuous glasslike reduction of the molecular dynamics of the confined liquid and SRS phases on cooling down to 250 K, where a solidlike behavior is finally reached by a two-step crystallization process.
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Affiliation(s)
- R Guégan
- Groupe Matière Condensée et Matériaux, CNRS-UMR 6626, Bâtiment 11A, Université de Rennes 1, F-35042 Rennes, France
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Frick B, Gruber B, Schroecksnadel K, Leblhuber F, Fuchs D. Homocysteine but not neopterin declines in demented patients on B vitamins. J Neural Transm (Vienna) 2006; 113:1815-9. [PMID: 16988797 DOI: 10.1007/s00702-006-0539-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 06/18/2006] [Indexed: 10/24/2022]
Abstract
Inflammation and immune system activation seem to play an important role in the development and progression of dementia. Hyperhomocysteinemia is common in various forms of dementia, and a significant relationship was found between concentrations of homocysteine and immune activation marker neopterin. B vitamin supplementation is able to slow-down homocysteine formation in patients. In an open-label study, effects of B vitamin supplementation (Beneuran compositum ) on concentrations of homocysteine and neopterin were investigated in 58 patients with Alzheimer's disease (n=30), vascular dementia (n=12) and mild cognitive impairment (n=16). In all groups of patients, a significant percentage of patients presented with homocysteine concentrations >15 micromol/L and with elevated concentrations of immune activation marker neopterin. Decline of homocysteine concentrations was observed after one month of B vitamin supplementation (all p<0.01; paired Kruskal-Wallisn-test). By contrast, neopterin concentrations remained unchanged (all p>0.05). B vitamin supplementation in patients with various forms of dementia did not influence neopterin concentrations, which indicates that the degree of immune activation and inflammation remained unchanged. The question remains, if lowering of homocysteine by folate supplementation alone could have any beneficial effect to modulate the course of dementia development and if longer period of supplementation would also ameliorate immune system activation status.
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Affiliation(s)
- B Frick
- Division of Biological Chemistry, Biocentre, Innsbruck Medical University, Innsbruck, Austria
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Arends J, Bodoky G, Bozzetti F, Fearon K, Muscaritoli M, Selga G, van Bokhorst-de van der Schueren MAE, von Meyenfeldt M, Zürcher G, Fietkau R, Aulbert E, Frick B, Holm M, Kneba M, Mestrom HJ, Zander A. ESPEN Guidelines on Enteral Nutrition: Non-surgical oncology. Clin Nutr 2006; 25:245-59. [PMID: 16697500 DOI: 10.1016/j.clnu.2006.01.020] [Citation(s) in RCA: 386] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Accepted: 01/20/2006] [Indexed: 02/06/2023]
Abstract
Enteral nutrition (EN) by means of oral nutritional supplements (ONS) and tube feeding (TF) offers the possibility of increasing or ensuring nutrient intake in cases where normal food intake is inadequate. These guidelines are intended to give evidence-based recommendations for the use of ONS and TF in cancer patients. They were developed by an interdisciplinary expert group in accordance with officially accepted standards, are based on all relevant publications since 1985 and were discussed and accepted in a consensus conference. Undernutrition and cachexia occur frequently in cancer patients and are indicators of poor prognosis. EN should be started if undernutrition already exists or if food intake is markedly reduced for more than 7-10 days. Standard formulae are recommended for EN. Nutritional needs generally are comparable to non-cancer subjects. In cachectic patients metabolic modulators such as progestins, steroids and possibly eicosapentaenoic acid may help to improve nutritional status. EN is indicated preoperatively for 5-7 days in cancer patients undergoing major abdominal surgery. During radiotherapy of head/neck and gastrointestinal regions dietary counselling and ONS prevent weight loss and interruption of radiotherapy. Routine EN is not indicated during (high-dose) chemotherapy.
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Affiliation(s)
- J Arends
- Department of Medical Oncology, Tumor Biology Center, Albert-Ludwigs-Universität, Freiburg, Germany.
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Hofmann WP, Bock H, Weber C, Tacke W, Pfaff R, Kihn R, Moog G, Kellner HU, Schöfer M, Frick B, Berg P, Rambow A, Friedrich-Rust M, Herrmann E, Sarrazin C, Zeuzem S. [Effectiveness of antiviral therapy in patients with chronic hepatitis C treated by private practice gastroenterologists]. Z Gastroenterol 2006; 44:25-31. [PMID: 16397836 DOI: 10.1055/s-2005-858960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The standard treatment for patients with chronic hepatitis C consists of pegylated interferon (PegIFN) alpha in combination with ribavirin. Information on treatment effectiveness outside clinical trials is sparse. To study community-based health care, a regional network supported by the German network of competence for hepatitis (Hep-Net) was created between gastroenterologists in private practice and a tertiary referral centre. A treatment register containing evidence-based guidelines was established and 212 consecutive patients who were treated with either PegIF Nalpha 2a/ribavirin (n = 126) or PegIFNalpha2b/ribavirin (n = 86) for 24 weeks (HCV genotype 2, 3) and 48 weeks (HCV genotype 1, 4, 5), respectively, were included and followed prospectively. Twenty-four weeks after cessation of antiviral treatment a sustained virological response was achieved in 54 % of the patients. By univariate analyses, infection with HCV genotypes 2 or 3 (p < 0.0001), younger age (p < 0.0001), normal gamma-glutamyltransferase levels before initiation of treatment (p = 0.003), and absence of language communication problems (p = 0.023) were associated with a sustained virological response. The presence of liver cirrhosis in patients with HCV genotype 1, 4, 5 infection was associated with lower sustained response rates (p = 0.025). Patients infected with HCV genotype 1 in whom the PegIFNalpha dose was reduced had higher virological relapse rates (p = 0.049). With regard to the treating physician, sustained virological response rates ranged from 26 - 67 % in patients infected with HCV genotype 1. Our study shows that virological response rates similar to those in international randomised clinical trials can be achieved by private practice gastroenterologists. The presented network allows characterization of the treatment outcome in chronic hepatitis C not only with regard to virus- and host-related factors but also on an individual physician basis.
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Affiliation(s)
- W P Hofmann
- Universitätsklinikum des Saarlandes, Kirrberger Strasse, 66421 Homburg/Saar
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Tyagi M, Arbe A, Colmenero J, Frick B, Stewart JR. Dynamic Confinement Effects in Polymer Blends. A Quasielastic Neutron Scattering Study of the Dynamics of Poly(ethylene oxide) in a Blend with Poly(vinyl acetate). Macromolecules 2006. [DOI: 10.1021/ma052642i] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Tyagi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - A. Arbe
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J. Colmenero
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - B. Frick
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J. R. Stewart
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
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Pérez Aparicio R, Arbe A, Colmenero J, Frick B, Willner L, Richter D, Fetters LJ. Quasielastic Neutron Scattering Study on the Effect of Blending on the Dynamics of Head-to-Head Poly(propylene) and Poly(ethylene−propylene). Macromolecules 2006. [DOI: 10.1021/ma052006k] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Pérez Aparicio
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
| | - A. Arbe
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
| | - J. Colmenero
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
| | - B. Frick
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
| | - L. Willner
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
| | - D. Richter
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
| | - L. J. Fetters
- Departamento de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain; Unidad Física de Materiales (CSIC-UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain; Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain; Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France; Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; and School of Chemical and Biomolecular Engineering, Cornell University, Ithaca,
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Schroecksnadel K, Frick B, Winkler C, Wirleitner B, Schennach H, Fuchs D. Aspirin downregulates homocysteine formation in stimulated human peripheral blood mononuclear cells. Scand J Immunol 2005; 62:155-60. [PMID: 16101822 DOI: 10.1111/j.1365-3083.2005.01654.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Moderate hyperhomocysteinaemia is established as an independent risk factor for atherosclerosis, thrombosis, stroke and dementia. Hyperhomocysteinaemia is mostly caused by the deficiency of B-vitamins folate and vitamin B12, which are essential cofactors in the remethylation of homocysteine to methionine. Interestingly, moderate hyperhomocysteinaemia is also often observed in chronic diseases, in which also elevated immune activation markers such as neopterin or sTNFR-II are found. In order to simulate immune activation in vitro, human peripheral blood mononuclear cells (PBMC) were stimulated with mitogens. Stimulation significantly increased homocysteine production in comparison with unstimulated PBMC; in parallel also neopterin formation was induced. Homocysteine formation was due to cell proliferation, proliferating T lymphocytes, and also the myelomonocytic cell line U-937 produced homocysteine. Treatment with the anti-inflammatory drug aspirin dose-dependently inhibited homocysteine production and also neopterin formation in human PBMC. Treatment with salicylic acid showed similar effects as aspirin; FACS analysis showed that both compounds inhibited cell proliferation by arresting cells in the G0/G1-phase. In U-937, both compounds also slightly induced apoptosis at 5 mm. Proliferation-induced homocysteine formation and in parallel also monocyte activation can be suppressed effectively by aspirin and salicylic acid in vitro, suggesting that also in vivo aspirin may downregulate not only inflammation but also formation of homocysteine.
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Affiliation(s)
- K Schroecksnadel
- Department of Biological Chemistry, Biocentre, Innsbruck Medical University, A-6020 Innsbruck, Austria
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Arrese-Igor S, Arbe A, Alegría A, Colmenero J, Frick B. Sub-Tg dynamics in polycarbonate by neutron scattering and its relation with secondary γ relaxation. J Chem Phys 2005; 123:014907. [PMID: 16035869 DOI: 10.1063/1.1948372] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have investigated the dynamics of phenylene rings in glassy bisphenol-A (BPA) polycarbonate (PC) by means of quasielastic neutron scattering. Taking advantage of selective deuteration of the samples, we have studied the incoherent scattering of hydrogens in phenylene rings on the one hand, and on the other hand the coherent quasielastic scattering of all the atoms in the sample. Two different types of neutron spectrometers, time of flight and backscattering, were used in order to cover a wide dynamic range, which extends from microscopic (approximately 10(-13) s) to mesoscopic (approximately 10(-9) s) times. Moreover, neutron-diffraction experiments with polarization analysis were carried out in order to characterize the structural features, and the relative coherent and incoherent contributions of the samples investigated. In contrast with previous studies of phenylene ring dynamics in BPA polysulfone performed by us also by neutron scattering, phenylene rings in BPA PC exhibit an "extra" motion in addition to those found for BPA polysulfone's phenylene rings. This extra motion of the rings in PC perfectly correlates with the main carbonate group motion followed by dielectric spectroscopy and allows us to (i) consistently interpret the PC's gamma relaxation in terms of two different motions; and (ii) experimentally confirm the relation between the motion of phenylene rings and carbonate groups within BPA PC formerly predicted by computational methods.
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Affiliation(s)
- S Arrese-Igor
- Departamento de Física de Materiales, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain.
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Baltá Calleja FJ, Arche AG, Ezquerra TA, Cruz CS, Batallán F, Frick B, Cabarcos EL. Structure and properties of ferroelectric copolymers of poly(vinylidene fluoride). ADVANCES IN POLYMER SCIENCE 2005. [DOI: 10.1007/3-540-56579-5_1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Affiliation(s)
- I. Quintana
- Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Donostia International Physics Center, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - A. Arbe
- Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Donostia International Physics Center, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J. Colmenero
- Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Donostia International Physics Center, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - B. Frick
- Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain, Unidad Física de Materiales (CSIC−UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain, Donostia International Physics Center, Apartado 1072, 20080 San Sebastián, Spain, and Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
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Arrese-Igor S, Arbe A, Alegrı́a A, Colmenero J, Frick B. Erratum: “Phenylene ring dynamics in bisphenol-A-polysulfone by neutron scattering” [J. Chem. Phys. 120, 423 (2004)]. J Chem Phys 2005. [DOI: 10.1063/1.1839573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ding Y, Novikov VN, Sokolov AP, A. Cailliaux,, Dalle-Ferrier C, Alba-Simionesco C, Frick B. Influence of Molecular Weight on Fast Dynamics and Fragility of Polymers. Macromolecules 2004. [DOI: 10.1021/ma0492420] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | - B. Frick
- Institute Laue Langevin, 38042 Grenoble, France
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Abstract
Moderate hyperhomocysteinemia is associated with an increased risk of atherosclerosis, thrombosis and neurodegenerative diseases. Homocysteine accumulation in the blood can be due to many underlying causes, which may interact with each other, e.g. genetic disposition and B-vitamin status. The role of the sulfur-containing amino acid homocysteine in the pathogenesis of diseases remains unclear, even if many studies suggest a causal relationship between homocysteine-mediated processes like oxidative stress, NO-inactivation and endothelial deficiency and atherogenesis. Proposed mechanisms of action of homocysteine are discussed, and the question is addressed, whether effects that are attributed to homocysteine, are not rather the consequence of folate and vitamin B12-deficiency. Deficiency of these B-vitamins in parallel with moderate hyperhomocysteinemia is often found in patients with enhanced activation of the cellular immune system, like Alzheimer's disease, rheumatoid arthritis and also vascular diseases. In patients with these diseases an association between homocysteine metabolism, oxidative stress and immune activation exists. On the one hand proliferation of immunocompetent cells having an enhanced demand for B-vitamins leads to the accumulation of homocysteine. On the other hand macrophages stimulated by TH1-type cytokine interferon-gamma form reactive oxygen species (ROS), which oxidize antioxidants, lipoproteins and oxidation-sensitive B-vitamins. Thereby Th1-type immune response could contribute importantly to the development of hyperhomocysteinemia, and may also be a major determinant of disease progression.
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Affiliation(s)
- K Schroecksnadel
- Institute of Medical Chemistry and Biochemistry, University of Innsbruck, Austria
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Arrese-Igor S, Arbe A, Alegría A, Colmenero J, Frick B. Phenylene ring dynamics in bisphenol-A-polysulfone by neutron scattering. J Chem Phys 2004; 120:423-36. [PMID: 15267305 DOI: 10.1063/1.1630013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have investigated the dynamics of phenylene rings in a glassy polysulfone (bisphenol-A-polysulfone) by means of quasielastic neutron scattering. Nowadays it is well known that these molecular motions are directly connected with the mechanical properties of engineering thermoplastics in general. The particular system investigated by us has the advantage that by selective deuteration of the methyl groups, the neutron scattering measured is dominated by the incoherent contribution from the protons in the phenylene rings. In this way, the dynamics of such molecular groups can be experimentally isolated. Two different types of neutron spectrometers: time of flight and backscattering, were used in order to cover a wide dynamic range, which extends from microscopic (10(-13) s) to mesoscopic (10(-9) s) times. Moreover, neutron diffraction experiments with polarization analysis were also carried out in order to characterize the structural features of the sample investigated. Fast oscillations of increasing amplitude with temperature and pi-flips are identified for phenylene rings motions. Due to the structural disorder characteristic of the amorphous state, both molecular motions display a broad distribution of relaxation times, which spreads over several orders of magnitude. Based on the results obtained, we propose a model for phenylene rings dynamics, which combines the two kinds of molecular motions identified. This model nicely describes the neutron scattering results in the whole dynamic range investigated.
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Affiliation(s)
- S Arrese-Igor
- Departamento de Física de Materiales UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain
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Frick B, Dalnoki-Veress K, Forrest JA, Dutcher J, Murray C, Higgins A. First inelastic neutron scattering studies on thin free standing polymer films. Eur Phys J E Soft Matter 2003; 12 Suppl 1:S93-S96. [PMID: 15011024 DOI: 10.1140/epjed/e2003-01-022-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2003] [Indexed: 05/24/2023]
Abstract
Glass transition studies in free standing polymer films have revealed values of the transition temperature, T(g), which were substantially reduced below the bulk for sufficiently thin films. Here we report on the preparation of two stacks of free standing polystyrene films: 70 films with a thickness of h approximately 107 nm and 140 films with h approximately 55 nm with equivalent total sample thicknesses of approximately 7.5 microm. We have performed the first measurements on such samples using inelastic neutron scattering, and demonstrate that inelastic neutron scattering experiments, performed on the time-of-flight spectrometer IN6 and the backscattering spectrometer IN16 at the Institut Laue-Langevin, are feasible.
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Affiliation(s)
- B Frick
- Institut Laue-Langevin, 6 rue Jules Horowitz, 38042 Grenoble, France
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Moreno AJ, Colmenero J, Alegría A, Alba-Simionesco C, Dosseh G, Morineau D, Frick B. Methyl group dynamics in a confined glass. Eur Phys J E Soft Matter 2003; 12 Suppl 1:S43-S46. [PMID: 15011013 DOI: 10.1140/epjed/e2003-01-011-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2003] [Indexed: 05/24/2023]
Abstract
We present a neutron scattering investigation on methyl group dynamics in glassy toluene confined in mesoporous silicates of different pore sizes. The experimental results have been analysed in terms of a barrier distribution model, such a distribution following from the structural disorder in the glassy state. Confinement results in a strong decreasing of the average rotational barrier in comparison to the bulk state. We have roughly separated the distribution for the confined state in a bulk-like and a surface-like contribution, corresponding to rotors at a distance from the pore wall respectively larger and smaller than the spatial range of the interactions which contribute to the rotational potential for the methyl groups. We have estimated a distance of 7 A as a lower limit of the interaction range, beyond the typical nearest-neighbour distance between centers-of-mass (4.7 A).
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Affiliation(s)
- A J Moreno
- Laboratoire des Verres, CNRS-UMR 5587, Université de Montpellier II, Bâtiment 13, 34095 Montpellier, France.
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