883 results on '"Wolfgang Weber"'
Search Results
352. Antipsychotic drug effects on motor activation measured by functional magnetic resonance imaging in schizophrenic patients
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Petra Hubrich-Ungureanu, Dieter F. Braus, Fritz A. Henn, Andreas Krier, Wolfgang Weber-Fahr, Alexander Sartorius, Sabine Stuck, Matthias Ruf, and Gabriele Ende
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Adult ,Male ,Psychosis ,medicine.medical_treatment ,medicine ,Humans ,Antipsychotic ,Clozapine ,Biological Psychiatry ,Blood-oxygen-level dependent ,medicine.diagnostic_test ,Supplementary motor area ,Motor Cortex ,Somatosensory Cortex ,Risperidone ,medicine.disease ,SMA ,Magnetic Resonance Imaging ,Oxygen ,Psychiatry and Mental health ,medicine.anatomical_structure ,Schizophrenia ,Anesthesia ,Female ,Primary motor cortex ,Functional magnetic resonance imaging ,Psychology ,Neuroscience ,Psychomotor Performance ,Antipsychotic Agents - Abstract
Brain function and laterality in schizophrenia were investigated by means of a simple motor task with a self-generated left-hand sequential finger opposition (SFO) using a whole-brain high-speed (100 ms per slice) functional imaging technique. Neuroleptic-naïve, acutely ill schizophrenic patients were compared to schizophrenic patients under stable neuroleptic medication and matched controls. The goal was to evaluate both the motor function in first-episode patients and possible effects of different neuroleptic treatments on functional MRI results. Forty patients satisfying ICD 10 criteria (F20.x) for schizophrenia and sex- and age-matched healthy volunteers participated in this study. All subjects underwent fMRI examinations on a conventional 1.5 T MR unit. The primary sensorimotor cortex and the high-order supplementary motor area (SMA) were evaluated. There was a close similarity in the activation of the primary and high-order (SMA) sensorimotor areas between first-episode schizophrenic patients and controls. In contrast, a significant reduction in the overall blood oxygen level dependent (BOLD) response was seen in sensorimotor cortices (contra- and ipsilateral) in schizophrenic patients under stable medication with typical neuroleptics. This effect was not present in patients treated with atypical antipsychotics. Both antipsychotic treatments, however, led to a significant reduction in activation of the SMA region compared to controls and neuroleptic-naïve subjects. Thus, the present study provides no evidence for the localized involvement of the primary motor cortex or the SMA as a relatively stable vulnerability marker in schizophrenia. There is, however, strong evidence that neuroleptics themselves influence fMRI activation patterns and that there are major differences between typical neuroleptics and atypical antipsychotics.
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- 1999
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353. Financial Participation in Europe-Determinants and Outcomes
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Yvonne Groening, Marion Festing, Wolfgang Weber, and Rüdiger Kabst
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Finance ,Organizational Behavior and Human Resource Management ,business.industry ,Strategy and Management ,Accounting management ,05 social sciences ,Financial ratio ,General Business, Management and Accounting ,Financial management ,Profit sharing ,Management of Technology and Innovation ,Human resource management ,0502 economics and business ,Economics ,Financial analysis ,Relevance (information retrieval) ,050207 economics ,business ,050203 business & management ,Limited company - Abstract
This article's objective is to analyse determinants and outcomes of financial participation in Europe. It starts off with a definition of the instruments, a review of the literature in the field of financial participation and a discussion on the relevance of financial participation in selected European countries. Choosing a rather inductive approach, the authors develop a model for financial participation. Based on the Cranfield data, the significance of the variables used in the model is tested. Union density, number of employees, public limited company status, geographical market and policy regarding pay and benefits came out as significant determinants for financial participation at company level. The environment, however, also bears influence. Organizations in Germany, France, Great Britain and Sweden show significantly different practices. Employee share ownership and profit sharing cannot only increase financial performance but also allow for efficient human resource management. Profit sharing increases profits and decreases absenteeism as well as staff turnover. The findings for employee share ownership are not that straightforward.
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- 1999
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354. Magnetite Nanoparticles for the Preparation of Ultrapure RAFT Polymers
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Wolfgang Weber, Fozi M. Saoud, Matthew P. Tonge, and Ronald D. Sanderson
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chemistry.chemical_classification ,Polymers and Plastics ,Organic Chemistry ,Radical polymerization ,Nanoparticle ,Solution polymerization ,Chain transfer ,Polymer ,Raft ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Polymer chemistry ,Materials Chemistry ,Magnetic nanoparticles ,Magnetite - Published
- 2008
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355. Democratic Competences and Social Practices in Organizations
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Wolfgang Weber, Michael Thoma, Annette Ostendorf, Lynne Chisholm, Wolfgang Weber, Michael Thoma, Annette Ostendorf, and Lynne Chisholm
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- Democracy, Philosophy, Democracy--Philosophy
- Abstract
The contributions in this book address the question of how to develop and foster democratic competences. This may take place via school curricula, resource materials and teaching/learning methods; in workplaces by means of formalised arrangements that encourage self-direction and through the informal processes engendered by expansive working environments; and in personal and community life, including in the course of incidental learning in social networks. The studies and analyses are somewhat nonconformist in its thematic spread and its boundary-crossing between disciplines and perspectives that conventionally live separate lives.
- Published
- 2012
356. Macht und Kommunikation : Augsburger Studien zur europäischen Kulturgeschichte
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Silvia Serena Tschopp, Wolfgang Weber, Silvia Serena Tschopp, and Wolfgang Weber
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- Communication and culture--Europe--History, Communication--Political aspects--Europe--History, Power (Social sciences)--Europe--History, Nobility--Europe--History
- Abstract
Macht ist nicht nur stets auf Kommunikation angewiesen, um sich durchzusetzen und erhalten zu können, sondern bereits selbst Ergebnis eines kommunikativen Prozesses. Um diesen Zusammenhängen genauer auf die Spur zu kommen, bedarf es einer neuen kulturhistorischen Perspektive. Das Institut für Europäische Kulturgeschichte der Universität Augsburg ist seit Langem damit befasst, diese Perspektive zu entwickeln und zu erproben. Der vorliegende Sammelband zeigt anhand einer Vielfalt von Fallstudien zur europäischen Geschichte von der Antike bis in die neueste Zeit, welche faszinierenden Aspekte auf diese Weise hervortreten können: Legitimationsstrategien, Ansprüche auf höchste Throne, Zugang zum Ohr des Königs, Theorien kommunikativen Umgangs mit Untertanen, wissenschaftsdisziplinäre Exklusionen, Machtzuschreibungen in der Erziehung, Macht und Ohnmacht in der religiösen Kommunikation, literarische Verarbeitungen im Hinblick auf das Todesurteil und den Krieg.
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- 2012
357. Verteidigung Leo Trotzkis : Zweite, erweiterte Auflage
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David North, Wolfgang Weber, David North, and Wolfgang Weber
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Leo Trotzki (1879–1940) gehört zu den größten und am meisten umstrittenen Persönlichkeiten in der Geschichte des 20. Jahrhunderts. Während seines Lebens war er das Ziel einer bösartigen Kampagne von Lügen und Verleumdungen durch das stalinistische Regime in der Sowjetunion, die in der Ermordung des Verbannten revolutionären Führers ihren Höhepunkt fand. 70 Jahre nach dem Mord an Trotzki finden längst ausgeräumte stalinistische Verzerrungen und Fälschungen der historischen Tatsachen ihren Weg in die akademische Literatur dieser Tage. In dieser umfassenden Analyse und Widerlegung von drei kürzlich veröffentlichten Biografien Leo Trotzkis durch die bekannten britischen Historiker Robert Service, Ian Thatcher und Geoffrey Swain wirft David North beunruhigende Fragen über den Zustand der zeitgenössischen historischen Wissenschaft auf. Die vorliegende zweite Auflage ist um drei Vorträge des Autors erweitert, die sich unter anderem mit der besonderen Bedeutung der Analysen Leo Trotzkis zu den Ursachen der deutschen Katastrophe von 1933 befassen. Außerdem ist im Anhang die Unterstützung dokumentiert, die dieses Buch bei namhaften Historikern in den USA, Deutschland, Österreich und der Schweiz gefunden hat. „Der Aufsatz von David North ist eine eindrucksvolle Arbeit – ausführlich, peinlich genau, gut dargelegt und verheerend in seiner Kritik. Er hat dem historischen Vermächtnis Trotzkis einen großen Dienst erwiesen.“ Professor Baruch Knei-Paz ist Autor von „The Social and Political Thought of Leon Trotsky” „Die große Leistung besteht darin, dass David North bei allem Engagement dennoch sachlich und objektiv argumentiert. Ich war erstaunt über die Genauigkeit und die Fülle an faktischen Details, womit er Autoren wie Robert Service Verdrehungen, Verleumdungen und Fälschungen nachweist und in diesem Zuge gleichzeitig ein Bild vom Leben und Werk Leo Trotzkis vor den Augen des Lesers entstehen lässt, das eher der geschichtlichen Wahrheit entspricht.“ Professor Hermann Weber, Mannheim, ist der Nestor der deutschen Stalinismus- und DDR-Forschung
- Published
- 2012
358. 18F-FDG PET in Non-Hodgkin's Lymphoma: Qualitative or Quantitative?
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Wolfgang Weber
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Oncology ,medicine.medical_specialty ,medicine.medical_treatment ,education ,Tumor response ,18f fdg pet ,Fluorodeoxyglucose F18 ,immune system diseases ,hemic and lymphatic diseases ,Internal medicine ,Image Interpretation, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,In patient ,Practice Patterns, Physicians' ,Clinical Trials as Topic ,Chemotherapy ,business.industry ,Lymphoma, Non-Hodgkin ,medicine.disease ,Lymphoma ,Non-Hodgkin's lymphoma ,Positron-Emission Tomography ,Practice Guidelines as Topic ,Radiopharmaceuticals ,business - Abstract
Several studies have documented that 18F-FDG PET is more accurate than CT for assessment of tumor response to chemotherapy in patients with Hodgkin's lymphoma (HL) and high-grade (aggressive) non-Hodgkin's lymphoma (NHL) ( [1][1],[2][2] ). On the basis of these data, the International Workshop
- Published
- 2007
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359. Electron paramagnetic resonance and Raman spectroscopy studies on carbon-doped MgB2 superconductor nanomaterials
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Bateni, Ali; Somer, Mehmet Suat (ORCID & YÖK ID 178882), Erdem, Emre; Repp, Sergej; Acar, Selçuk; Kokal, İlkin; Haessler, Wolfgang; Weber, Stefan, College of Sciences, Department of Chemistry, Bateni, Ali; Somer, Mehmet Suat (ORCID & YÖK ID 178882), Erdem, Emre; Repp, Sergej; Acar, Selçuk; Kokal, İlkin; Haessler, Wolfgang; Weber, Stefan, College of Sciences, and Department of Chemistry
- Abstract
Undoped and carbon-doped magnesium diboride (MgB2) samples were synthesized using two sets of mixtures prepared from the precursors, amorphous nanoboron, and as-received amorphous carbon-doped nanoboron. The microscopic defect structures of carbon-doped MgB2 samples were systematically investigated using X-ray powder diffraction, Raman and electron paramagnetic resonance spectroscopy. Mg vacancies and C-related dangling-bond active centers could be distinguished, and sp(3)-hybridized carbon radicals were detected. A strong reduction in the critical temperature T-c was observed due to defects and crystal distortion. The symmetry effect of the latter is also reflected on the vibrational modes in the Raman spectra. (C) 2015 AIP Publishing LLC., Deutsche Forschungsgemeinschaft (DFG); Koç University Graduate Program; Koç University Surface Science and Technology Center (KUYTAM)
- Published
- 2015
360. Numerical modeling of a sub-sonic moving load front along a rod's skin
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Bernd W. Zastrau, Yannick F. Fangye, Wolfgang Weber, and Daniel Balzani
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Engineering ,business.industry ,Front (oceanography) ,Moving load ,Mechanical engineering ,Numerical modeling ,Boundary value problem ,business - Abstract
In this contribution the dynamical behaviour of a semi-infinite rod subjected to a longitudinal load moving along the rod's skin is investigated both analytically and numerically. By means of the analytical results the numerical model is validated and thus can be used for more advanced studies e. g. concerning dynamic fibre pull-out phenomena. These forthcoming studies involve spatially moving boundary conditions which are also modeled within the present model in a first step. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)
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- 2015
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361. S.19.02 Structural and functional imaging effects of CNVs in mouse and man
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Wolfgang Weber-Fahr, Adam J. Schwarz, Jesper F. Bastlund, Natalia Gass, Michael Didriksen, Andreas Meyer-Lindenberg, and Alexander Sartorius
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Pharmacology ,Genetics ,Functional imaging ,Psychiatry and Mental health ,Neurology ,Pharmacology (medical) ,Neurology (clinical) ,Computational biology ,Biology ,Biological Psychiatry - Published
- 2015
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362. Total Scattering Cross Section and Spin Motion of Low Energy Electrons Passing through a Ferromagnet
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H. C. Siegmann, R. Burgermeister, D. Y. Oberli, S. Riesen, and Wolfgang Weber
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Physics ,Condensed matter physics ,Scattering ,media_common.quotation_subject ,High Energy Physics::Phenomenology ,General Physics and Astronomy ,Scattering length ,Electron ,Asymmetry ,Condensed Matter::Materials Science ,Magnetization ,Mathematics::Probability ,Ferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Nuclear cross section ,Atomic physics ,Spin (physics) ,media_common - Abstract
It is shown that the spin asymmetry of the elastic transmission of electrons through ferromagnetic films can approach unity. The polycrystalline Co films are a few nanometers thick and saturated with the magnetization $\stackrel{\ensuremath{\rightarrow}}{M}$ in the plane. The contribution of spin-productive scattering events is below $5%$. If the electron spin at incidence is chosen to be perpendicular to $\stackrel{\ensuremath{\rightarrow}}{M}$, it rotates into the direction of $\stackrel{\ensuremath{\rightarrow}}{M}$ and also precesses around it.
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- 1998
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363. Functional flexibility: merely reacting or acting strategically?
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Rüdiger Kabst, Wolfgang Weber, Maria Rodehuth, and Andrea Friedrich
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Human resource management system ,Flexibility (engineering) ,Organizational Behavior and Human Resource Management ,Process management ,business.industry ,Strategic human resource planning ,Human resource management ,Industrial relations ,Resource allocation ,Job rotation ,Resource management ,Operations management ,Business ,Human resources - Abstract
This article raises the question of to what extent functional flexibility is an operatively designed approach with which European companies confront current short‐term changes in their environment, and whether functional flexibility is integrated into long‐term human resource strategies. The proposition is tested that organisations with a strategic human resource management in the sense of a coordinated, objective‐oriented personnel management pattern, show a higher probability of using job rotation than organisations lacking a strategic‐oriented human resource management approach.
- Published
- 1998
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364. Oscillatory magnetic properties
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Rolf Allenspach and Wolfgang Weber
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Condensed Matter::Materials Science ,Magnetic anisotropy ,Coupling (physics) ,Materials science ,General Computer Science ,Spin polarization ,Magnetic moment ,Condensed matter physics ,Oscillation ,Condensed Matter::Superconductivity ,Thin film ,Quantum Hall effect ,Magnetic hysteresis - Abstract
The recent discovery of oscillations in interlayer exchange coupling as a function of nonmagnetic spacer layer thickness has led to a widespread interest in oscillatory magnetic properties in layered structures for both basic and applied reasons. In this overview, several oscillatory magnetic properties are discussed for a particular model system. We have chosen epitaxial fcc Co films grown on Cu(100) as a base structure and have selected additional epitaxial overlayers to study interlayer exchange coupling, induced magnetic moments, magneto-optical properties, and magnetic anisotropy.
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- 1998
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365. Contents Vol. 140, 2006
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F. de la Torre-Martínez, Christian Betzel, Miki Abo, Françoise André, Makoto Hattori, T. Hansson, Michel Laviolette, Philippe Moingeon, Philippe Harzic, Masaki Fujimura, Julia Horn, S. Ahlstedt, Redwan Moqbel, Conny Höflich, Marie-Noëlle Couret, Volker Wahn, Yuko Waseda, Toshiyuki Yamamoto, Thierry Batard, J. Magnusson, Henri Chabre, Fook Tim Chew, M.P. Borres, J. Ring, M.D. Ibáñez, Alexandre Hrabina, Kirsten Gehlhar, Shiho Furusho, I. Münster, Wolfgang Weber, Johsuke Hara, Claudine Ferland, K. R. Rajashankar, Bertrand Villet, Masahide Yasui, C. Traidl-Hoffmann, M. Boquete, Hans-Dieter Volk, U. Bengtsson, Yoriko Herai, Francis Davoine, Hanae Wada, L. Hulthén, A.I. Tabar, Robert Bunk, Takashi Sone, Tsukasa Uno, Eckhard Hofmann, Tadashi Yoshida, Kazuo Kasahara, Yoshitaka Oribe, Albrecht Bufe, Joo Eun Lee, Dominique Faccenda, Sandra Werner, Aki Hirano, Noriyuki Ohkura, Jamila Chakir, Kathrin Schmolke, Darryl J. Adamko, Koji Takahashi, P. Lemoine, F. Rodriguez, C.G.B. Peterson, Ilka Schulze, H. Behrendt, Shigeharu Myou, Sock Yong Goh, Xue Zhi Bi, Anna-Maria Dittrich, Claude André, and J. van Odijk
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Immunology ,Immunology and Allergy ,General Medicine ,Biology - Published
- 2006
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366. Die wirtschaftliche Bedeutung des Sports
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Claudia Schnieder, Norbert Kortlüke, Klaus Heinemann, Birgit Horak, and Wolfgang Weber
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Political science ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,Humanities - Abstract
Sporttreiben kostet Geld and Zeit. Es entstehen Kosten fir die Sportausiibung selbst, also fiir Mitgliedschaft in Sportvereinen oder bei gewerblichen Sportanbietern, fur Sportgerate and Sportkleidung, fur Trainer, Nutzungsrechte an Sportstatten und -geraten, fur Eintrittskarten zu Sportveranstaltungen; es entstehen Kosten fiir die Fahrt zwischen Wohn-/Arbeitsort and Sportgelegenheit sowie Zusatzkosten etwa fur Verpflegung and Unterbringung. Man benotigt Zeit fur die Sportausiibung selbst, weiter fur die Anfahrt zur Sportgelegenheit, u. U. auch fur die Herstellung and die Pflege der Sportgerate and -anlagen sowie for Vereinswesen and ehrenamtliche Tatigkeit im Verein.
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- 1997
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367. Magnetic anisotropy oscillations (invited)
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Rolf Allenspach, A. Bischof, Danilo Pescia, Ch. Würsch, Wolfgang Weber, and Christian H. Back
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Materials science ,Quantitative Biology::Neurons and Cognition ,Condensed matter physics ,General Physics and Astronomy ,Electron ,Magnetic hysteresis ,Epitaxy ,Condensed Matter::Materials Science ,Magnetic anisotropy ,Hysteresis ,Ferromagnetism ,Condensed Matter::Superconductivity ,Monolayer ,Anisotropy - Abstract
The magnetic anisotropy in Co films epitaxially grown on Cu(001) is investigated by measuring magneto-optical Kerr hysteresis loops during film growth. As a function of Co thickness the magnetic anisotropy oscillates with a period of 1 monolayer. These oscillations are attributed to the periodic variations of the film morphology alternating between filled and incompletely filled atomic layers. Upon coverage of the Co films with Cu overlayers the anisotropy of the magnetic film is found to oscillate with increasing Cu layer thickness. We relate these oscillations to quantum interferences due to the confinement of electrons in ultrathin films.
- Published
- 1997
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368. Rotation and inversion barriers in N-methylmethanesulfonamide from ab initio calculations
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Wolfgang Weber, Jochen Heyd, and Walter Thiel
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Maxima and minima ,Inversion barrier ,Chemistry ,Ab initio quantum chemistry methods ,Quantum mechanics ,Physics::Atomic and Molecular Clusters ,Ab initio ,Intrinsic reaction coordinate ,Inversion (meteorology) ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry ,Molecular physics - Abstract
Rotation and inversion barriers in N-methylmethanesulfonamide were calculated using restricted Hartree-Fock and MP2 ab initio methods with 6-31G∗ and larger basis sets. The two enantiomeric global minima are separated by a single transition state along the minimum energy path. The intrinsic reaction coordinate combines the two necessary motions: rotation and inversion.
- Published
- 1997
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369. Tracer Studies with Crude U-13C-Lipid Mixtures
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Wolfgang Weber, Ernst Kupfer, Adelbert Bacher, and Wolfgang Eisenreich
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chemistry.chemical_classification ,Claisen condensation ,Chromatography ,biology ,Linoleic acid ,Streptomyces toxytricini ,Fatty acid ,Cell Biology ,Lipstatin ,biology.organism_classification ,Biochemistry ,chemistry.chemical_compound ,chemistry ,Moiety ,Organic chemistry ,Fermentation ,Molecular Biology ,Unsaturated fatty acid - Abstract
The biosynthesis of the pancreatic lipase inhibitor lipstatin was investigated by fermentation experiments using cultures of Streptomyces toxytricini, which were supplied with soybean oil and a crude mixture of U-13C-lipids obtained from algal biomass cultured with 13CO2. Lipstatin was analyzed by one- and two-dimensional NMR spectroscopy. 13C total correlation spectroscopy and INADEQUATE experiments show that two fatty acid fragments containing 14 and 8 carbon atoms, respectively, are incorporated en bloc into lipstatin. The 14-carbon fragment is preferentially derived from the unsaturated fatty acid fraction, as shown by an experiment with hydrogenated U-13C-lipid mixture, which is conducive to labeling of the 8-carbon moiety but not of the 14-carbon moiety. The data indicate that the lipstatin molecule can be assembled by Claisen condensation of octanoyl-CoA with 3-hydroxy-∆5,8-tetradecanoyl-CoA obtained by β oxidation of linoleic acid. The formation of lipstatin from acetate units by a polyketide-type pathway is ruled out conclusively by these data. The data show that surprisingly clear labeling patterns can be obtained in studies with crude, universally 13C-labeled precursor mixtures that are proffered together with a large excess of unlabeled material. One- and two-dimensional 13C total correlation spectroscopy analyses are suggested as elegant methods for the delineation of contiguously 13C-labeled biosynthetic blocks.
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- 1997
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370. Sub-Anesthetic Ketamine Modulates Intrinsic BOLD Connectivity Within the Hippocampal-Prefrontal Circuit in the Rat
- Author
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Celine Risterucci, Natalia Gass, Michael Spedding, Esther Schenker, Adam J. Schwarz, Wolfgang Weber-Fahr, Lei Zheng, Alexander Sartorius, and Andreas Meyer-Lindenberg
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Male ,Statistics as Topic ,Hippocampus ,Prefrontal Cortex ,Hippocampal formation ,Rats, Sprague-Dawley ,Retrosplenial cortex ,Heart Rate ,medicine ,Image Processing, Computer-Assisted ,Animals ,Ketamine ,Prefrontal cortex ,Pharmacology ,Analgesics ,Dose-Response Relationship, Drug ,Psychotomimetic ,medicine.disease ,Magnetic Resonance Imaging ,Rats ,Oxygen ,Psychiatry and Mental health ,Schizophrenia ,NMDA receptor ,Original Article ,Nerve Net ,Psychology ,Neuroscience ,medicine.drug - Abstract
Dysfunctional connectivity within the hippocampal-prefrontal circuit (HC-PFC) is associated with schizophrenia, major depression, and neurodegenerative disorders, and both the hippocampus and prefrontal cortex have dense populations of N-methyl-D-aspartate (NMDA) receptors. Ketamine, a potent NMDA receptor antagonist, is of substantial current interest as a mechanistic model of glutamatergic dysfunction in animal and human studies, a psychotomimetic agent and a rapidly acting antidepressant. In this study, we sought to understand the modulatory effect of acute ketamine administration on functional connectivity in the HC-PFC system of the rat brain using resting-state fMRI. Sprague-Dawley rats in four parallel groups (N=9 per group) received either saline or one of three behaviorally relevant, sub-anesthetic doses of S-ketamine (5, 10, and 25 mg/kg, s.c.), and connectivity changes 15- and 30-min post-injection were studied. The strongest effects were dose- and exposure-dependent increases in functional connectivity within the prefrontal cortex and in anterior-posterior connections between the posterior hippocampus and retrosplenial cortex, and prefrontal regions. The increased prefrontal connectivity is consistent with ketamine-induced increases in HC-PFC electroencephalographic gamma band power, possibly reflecting a psychotomimetic aspect of ketamine's effect, and is contrary to the data from chronic schizophrenic patients suggesting that ketamine effect does not necessarily parallel the disease pattern but might rather reflect a hyperglutamatergic state. These findings may help to clarify the brain systems underlying different dose-dependent behavioral profiles of ketamine in the rat.
- Published
- 2013
371. Exercise boosts hippocampal volume by preventing early age-related gray matter loss
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Johannes, Fuss, Sarah V, Biedermann, Claudia, Falfán-Melgoza, Matthias K, Auer, Lei, Zheng, Jörg, Steinle, Felix, Hörner, Alexander, Sartorius, Gabriele, Ende, Wolfgang, Weber-Fahr, and Peter, Gass
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Male ,Mice, Inbred C57BL ,Aging ,Mice ,Imaging, Three-Dimensional ,Physical Conditioning, Animal ,Animals ,Longitudinal Studies ,Cranial Irradiation ,Hippocampus ,Magnetic Resonance Imaging ,Running - Abstract
Recently, a larger hippocampus was found in exercising mice and men. Here we studied the morphological underpinnings in wheel running mice by longitudinal magnetic resonance imaging. Voxel-based morphometry revealed that running increases hippocampal volume by inhibiting an early age-related gray matter loss. Disruption of neurogenesis-related neuroplasticity by focalized irradiation is sufficient to block positive effects of exercise on macroscopic brain morphology.
- Published
- 2013
372. 123I-iodobenzamide SPECT is not an independent predictor of dopaminergic responsiveness in patients with suspected atypical parkinsonian syndromes
- Author
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Bernhard Hellwig, Werner Vach, Florian Amtage, Sabine Hellwig, Oliver H. Winz, Philipp T. Meyer, Cornelius Weiller, Annabelle Kreft, Oliver Tüscher, and Wolfgang Weber
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Oncology ,Male ,medicine.medical_specialty ,Pathology ,Multivariate analysis ,Dopamine ,chemistry.chemical_compound ,Iodobenzamide ,Parkinsonian Disorders ,Dopamine receptor D3 ,Internal medicine ,Dopamine receptor D2 ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Tomography, Emission-Computed, Single-Photon ,Univariate analysis ,business.industry ,Iodobenzenes ,Receptors, Dopamine D2 ,Parkinsonism ,Confounding ,Dopaminergic ,Age Factors ,Middle Aged ,medicine.disease ,Treatment Outcome ,chemistry ,Multivariate Analysis ,Female ,business - Abstract
The prediction of dopaminergic responsiveness in patients with parkinsonism is desirable for effective treatment strategies. We investigated whether striatal dopamine D2/D3 receptor (D2R) binding assessed by 123I-iodobenzamide SPECT is an independent predictor of dopaminergic responsiveness in patients with parkinsonism. Methods: Seventy-eight patients with clinically suspected atypical parkinsonian syndrome (APS) were prospectively recruited for imaging. To quantify striatal D2R binding, 123I-iodobenzamide SPECT datasets were subjected to an observer-independent, regions-of-interest analysis. A final clinical diagnosis of Lewy-body disease (LBD) or APS was made after a mean follow-up of 12 mo. On the basis of follow-up data, dopaminergic responsiveness was classified as 0 (none), 1 (transient), 2 (sustained mild), or 3 (sustained strong). Uni- and multivariate analyses of the relationship between treatment response, D2R binding, and confounding variables were conducted. Results: Sixty patients with clinically verified LBD (n = 28; 22/28 with Parkinson disease) or APS (n = 32), in whom dopaminergic responsiveness could be assessed (n = 19/13/15/13 in categories 0/1/2/3; 18 were excluded because of insufficient dosing), were included in the statistical analysis. Univariate analyses revealed that a sustained treatment response was significantly associated with higher D2R binding, clinical diagnosis of LBD, lower Hoehn and Yahr scores, and younger age. After multivariate correction of D2R binding for diagnosis, age, symptom duration, Hoehn and Yahr score, and dopaminergic pretreatment, no association was found between D2R binding and treatment response, either in the pooled group or in LBD or APS subgroups. Conclusion: Striatal D2R binding assessed by 123I-iodobenzamide SPECT does not provide additional predictive information about treatment response beyond other clinical variables, most notably the clinical diagnosis.
- Published
- 2013
373. ChemInform Abstract: 2,2,4,4-Tetrathio Substituted 1,3-Dithietanes
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Wolfgang Weber, Harald Pasch, and Helen Chirowodza
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Thiophosgene ,chemistry.chemical_compound ,Chemistry ,General Medicine ,Medicinal chemistry - Abstract
The title compounds (III) are formed by reaction of thiophosgene with carbonotrithioates or O-ethyldithiocarbonates (I).
- Published
- 2013
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374. Chemisorption of manganese phthalocyanine on Cu(001) surface promoted by van der Waals interactions
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Jörg Zegenhagen, Wulf Wulfhekel, Fatima Ibrahim, S. Javaid, Mebarek Alouani, Sébastien Lebègue, Jacek Arabski, Wolfgang Weber, Eric Beaurepaire, Samy Boukari, Martin Bowen, Blanka Detlefs, D. Spor, F. Djeghloul, T. Miyamachi, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Cristallographie, Résonance Magnétique et Modélisations (CRM2), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), and Karlsruhe Institute of Technology (KIT)
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Materials science ,Aucun ,Charge density ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Dipole ,Adsorption ,Chemical physics ,Chemisorption ,0103 physical sciences ,symbols ,[CHIM.CRIS]Chemical Sciences/Cristallography ,Molecule ,Density functional theory ,van der Waals force ,Atomic physics ,010306 general physics ,0210 nano-technology ,Ground state - Abstract
van der Waals (vdW) interactions within density functional theory are shown to strongly reduce the distance between manganese phthalocyanine (MnPc) and a Cu(001) surface to that found by x-ray standing wave experiments. Thus, the physisorbed ground state that is predicted within the generalized-gradient approximation formalism is replaced by a chemisorbed ground state once vdW interactions are taken into account. These findings indicate how to systematically obtain the correct theoretical adsorption distance for complex molecules and thus accurately predict the properties of the ensuing molecule/metal interface. The reduction of the experimental work function upon molecular adsorption is satisfactorily accounted for and explained in terms of Friedel-like oscillations of the charge density at the vicinity of the MnPc molecule that change the sign of the charge transfer electric dipole. This shows how vdW interactions can strongly impact charge injection in organic electronic devices. DOI: 10.1103/PhysRevB.87.155418
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- 2013
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375. Direct observation of a highly spin-polarized organic spinterface at room temperature
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Riccardo Bertacco, Amina Taleb-Ibrahimi, Samy Boukari, Christian Rinaldi, Wolfgang Weber, S. Javaid, P. Le Fèvre, Eric Beaurepaire, Fatima Ibrahim, Richard Mattana, François Bertran, Mebarek Alouani, Philippe Ohresser, J. Arabski, Pierre Seneor, N. B. Brookes, Loïc Joly, F. Djeghloul, T. Miyamachi, J. P. Kappler, Pardeep K. Thakur, Martin Bowen, A. Jaafar, Fabrice Scheurer, Wulf Wulfhekel, Matteo Cantoni, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Politecn Milan, LNESS Dipartimento Fis, I-22100 Como, Italy, Paul Scherrer Inst, CH-5232 Villigen, Switzerland, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Karlsruhe Inst Technol, Ctr Funct Nanostruct, D-76131 Karlsruhe, Germany, Karlsruhe Inst Technol, Inst Phys, D-76131 Karlsruhe, Germany, Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, Université Paris-Sud - Paris 11 (UP11), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique
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Aucun ,Electron ,02 engineering and technology ,7. Clean energy ,01 natural sciences ,chemistry.chemical_compound ,Organic spintronics ,Electronic circuit ,Spin-½ ,[PHYS]Physics [physics] ,Spin-polarized photoemission spectroscopy ,Condensed Matter - Materials Science ,Multidisciplinary ,Condensed matter physics ,Spin polarization ,Magnetic moment ,Applied Mathematics ,Physics ,Spin-polarized interface states ,Computer Science Applications1707 Computer Vision and Pattern Recognition ,Electrical and Electronic Engineering ,Electronic, Optical and Magnetic Materials ,Condensed Matter Physics ,Current source ,021001 nanoscience & nanotechnology ,Thermal conduction ,Chemical physics ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology ,Materials science ,FOS: Physical sciences ,Article ,Condensed Matter::Materials Science ,Atomic orbital ,0103 physical sciences ,Electronic ,Molecule ,ddc:530 ,Optical and Magnetic Materials ,Spin (physics) ,010306 general physics ,Spintronics ,business.industry ,Materials Science (cond-mat.mtrl-sci) ,Organic semiconductor ,Semiconductor ,Ferromagnetism ,chemistry ,Phthalocyanine ,business - Abstract
International audience; Organic semiconductors constitute promising candidates toward large-scale electronic circuits that are entirely spintronics-driven. Toward this goal, tunneling magnetoresistance values above 300% at low temperature suggested the presence of highly spin-polarized device interfaces. However, such spinterfaces have not been observed directly, let alone at room temperature. Thanks to experiments and theory on the model spinterface between phthalocyanine molecules and a Co single crystal surface, we clearly evidence a highly efficient spinterface. Spin-polarised direct and inverse photoemission experiments reveal a high degree of spin polarisation at room temperature at this interface. We measured a magnetic moment on the molecule's nitrogen p orbitals, which substantiates an ab-initio theoretical description of highly spin-polarised charge conduction across the interface due to differing spinterface formation mechanisms in each spin channel. We propose, through this example, a recipe to engineer simple organic-inorganic interfaces with remarkable spintronic properties that can endure well above room temperature
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- 2013
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376. Crystallization and Preliminary Diffraction Data of a Major Pollen Allergen
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Gabriele Schramm, Wolfgang Weber, Wolf-Meinhard Becker, Albrecht Bufe, Christian Betzel, Zbigniew Dauter, Max Schlaak, Arnd Petersen, and Markus Perbandt
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Gel electrophoresis ,chemistry.chemical_classification ,Chromatography ,biology ,Chemistry ,Biological activity ,Cell Biology ,medicine.disease_cause ,Biochemistry ,respiratory tract diseases ,law.invention ,Amino acid ,Allergen ,law ,otorhinolaryngologic diseases ,medicine ,biology.protein ,Ribonuclease ,Crystallization ,Protein crystallization ,Molecular Biology ,Peptide sequence - Abstract
Group V major allergen Phl p 5b of timothy grass pollen induces allergic rhinitis and bronchial asthma in 90% of grass pollen-allergic patients. In addition to its allergenicity ribonuclease activity has recently been attributed to this 29-kDa protein. The allergen was expressed in Escherichia coli and subsequently purified. Spontaneous conversion of these preparations to a mixture of various forms with molecular sizes between 10 and 29 kDa was consistently observed. Surprisingly, crystals could be grown from this heterogenous preparation. Single crystals, redissolved and analyzed by SDS-polyacrylamide gel electrophoresis and immunoblot, yielded one distinct low molecular weight protein, which was identified by amino acid sequencing as the C-terminal 13-kDa portion of the allergen. Histamine release assays with single crystal solutions using basophils of an allergic patient demonstrated allergenicity comparable with that of the holo-allergen. By contrast, RNase activity of the crystallized C-terminal form was 23 times higher than that of the full-length parent allergen. Crystals were used to collect preliminary diffraction data; the space group was evaluated to I4122 with cell dimensions of a = 87.7 A, b = 87.7 A, and c = 59.6 A. We conclude that preferential crystal growth of the 13-kDa form is indicative of a compact conformation of this particular C-terminal portion of the allergen. Thus, we show here that protein crystallization is not only a prerequisite for structural analyses, but it also can provide a unique separation technique to localize the functional domain of a major allergen.
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- 1996
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377. Structural relaxation and magnetic anisotropy in Co/Cu(001) films
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U. May, Jürgen Fassbender, Wolfgang Weber, Burkard Hillebrands, R. M. Jungblut, Christian H. Back, Gernot Güntherodt, Rolf Allenspach, B. Schirmer, and A. Bischof
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Condensed Matter::Materials Science ,Magnetic anisotropy ,Reflection (mathematics) ,Kerr effect ,Materials science ,Strain (chemistry) ,Condensed matter physics ,Relaxation (NMR) ,Electron ,Critical thickness - Abstract
The magnetic anisotropy of Co/Cu(001) films has been investigated by the magneto-optical Kerr effect, both in the pseudomorphic growth regime and above the critical thickness where strain relaxation sets in. A clear correlation between the onset of strain relaxation---as measured by means of reflection high-energy electron diffraction---and changes of the magnetic anisotropy has been found. \textcopyright{} 1996 The American Physical Society.
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- 1996
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378. Characterization of the C-terminal domain of ras-GTPase-activating protein (ras-GAP) as substrate for epidermal growth factor receptor and p60c-src kinase
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Rainer Laufs, Wolfgang Weber, Sandra Roloff, Lutz Kornetzky, Peter Borowski, and Max Heiland
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Phosphopeptides ,GTPase-activating protein ,Ovalbumin ,Clinical Biochemistry ,macromolecular substances ,Biology ,environment and public health ,Biochemistry ,Histones ,Phosphoserine ,chemistry.chemical_compound ,Tumor Cells, Cultured ,Genetics ,Humans ,Magnesium ,Polylysine ,Trypsin ,Protein phosphorylation ,Phosphorylation ,Tyrosine ,Phosphotyrosine ,Molecular Biology ,Manganese ,GTPase-Activating Proteins ,Autophosphorylation ,Proteins ,Tyrosine phosphorylation ,Cell Biology ,Peptide Fragments ,Cell biology ,Enzyme Activation ,ErbB Receptors ,Kinetics ,Phosphothreonine ,src-Family Kinases ,Polyglutamic Acid ,chemistry ,ras GTPase-Activating Proteins ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,GRB2 ,Proto-oncogene tyrosine-protein kinase Src - Abstract
We describe in vitro tyrosine phosphorylation of the C-terminal 334 amino acids of ras-GTPase-activating protein (ras-GAP)1 that contains the activity domain for ras interaction. To date, there have been no other phosphorylation sites determined than the reported in N-terminal domain of ras-GAP Tyr-460, which is considered to be the major phosphorylation site of ras-GAP. In our assays some differences of the kinetic parameters were observed when the reaction was catalyzed by EGF-R compared to p60c-src. Enzyme specific regulation of activity is associated with autophosphorylation which leads to reduced (in case of EGF-R) or increased (in case of p60c-src) phosphorylation of the C-terminal 334 amino acids of ras-GAP (GAP334). Because of the characteristics of these investigated reactions the phosphorylation of GAP334 seems to be-independent from the presence of SH2 or SH3 domains-triggered off by complex mechanisms different from those regulating the phosphorylation at Tyr-460.
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- 1996
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379. Oscillatory Magnetic Anisotropy and Quantum Well States in Cu/Co/Cu(100) Films
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A. Bischof, Christian H. Back, Ch. Würsch, Wolfgang Weber, Danilo Pescia, and Rolf Allenspach
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Condensed Matter::Materials Science ,Magnetic anisotropy ,Materials science ,Quantitative Biology::Neurons and Cognition ,Condensed matter physics ,Computer Science::Networking and Internet Architecture ,General Physics and Astronomy ,Quantum well states ,Computer Science::Distributed, Parallel, and Cluster Computing ,Overlayer - Abstract
The magnetic anisotropy of Co films grown on stepped Cu(100) substrates is found to oscillate with varying Cu overlayer thickness. We relate these oscillations to the occurrence of quantum well states in the Cu overlayer.
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- 1996
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380. 18F-FDG PET is an independent outcome predictor in primary central nervous system lymphoma
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Elisabeth Schorb, Jürgen Finke, Wolfgang Weber, Kristina Fritsch, Michael Mix, Vanessa Haug, Philipp T. Meyer, Gerald Illerhaus, Claudia Hader, and Benjamin Kasenda
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Adult ,Genetic Markers ,Male ,Risk ,medicine.medical_specialty ,Time Factors ,Standardized uptake value ,Logistic regression ,Gastroenterology ,Disease-Free Survival ,Central Nervous System Neoplasms ,Outcome predictor ,Fluorodeoxyglucose F18 ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Proportional Hazards Models ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Proportional hazards model ,Lymphoma, Non-Hodgkin ,Hazard ratio ,Primary central nervous system lymphoma ,Brain ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Lymphoma ,Treatment Outcome ,Positron-Emission Tomography ,Regression Analysis ,Female ,business ,Nuclear medicine ,Tomography, X-Ray Computed - Abstract
Primary central nervous system (CNS) lymphoma is an aggressive non-Hodgkin lymphoma with poor prognosis. We evaluated pretreatment 18F-FDG PET as a prognostic marker in primary CNS lymphoma. Methods: Forty-two immunocompetent patients with newly diagnosed primary CNS lymphoma who underwent pretreatment 18F-FDG PET were retrospectively analyzed. Baseline status and response to treatment were evaluated by MR imaging. Tumor maximum standardized uptake values were assessed by volume-of-interest analyses using an automatic isocontour definition. A 10-step semiquantitative visual rating system (metabolic imaging lymphoma aggressiveness scale, or MILAS) was used to assess primary CNS lymphoma metabolism as a marker of clinical aggressiveness. Logistic regression, log-rank testing, and multivariable Cox regression were used to investigate the association between 18F-FDG uptake and tumor response and survival. Results: Mean maximum standardized uptake value correlated linearly with MILAS. The distribution of patients according to MILAS (0–9) was 0%, 28.6%, 23.8%, 21.4%, 11.9%, 4.8%, 7.1%, 0%, 0%, and 2.4%. There was no correlation between MILAS and response to treatment. Respective 2- and 5-y survival rates were 52% and 32% for progression-free survival (PFS) and 64% and 50% for overall survival (OS). A cutoff at MILAS 3 was a good separator for PFS (median: 54.7 mo [≤3], 3.8 mo [>3], P = 0.0272) and OS (median: not reached [≤3], 13.8 mo [>3], P = 0.131). In multivariable analyses, increasing MILAS was significantly associated with shorter PFS (hazard ratio, 1.49, P = 0.006) and OS (hazard ratio, 1.43, P = 0.018). Conclusion: Increased pretreatment 18F-FDG uptake may offer new opportunities for baseline risk evaluation in untreated primary CNS lymphoma.
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- 2012
381. SURFACE-SCIENCE TECHNIQUES APPLIED TO MAGNETIC MATERIALS
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Wolfgang Weber
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Surface (mathematics) ,Materials science ,Materials Chemistry ,Surfaces and Interfaces ,Composite material ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 1995
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382. Submonolayers of adsorbates on stepped Co/Cu(100): Switching of the easy axis
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Urs Ramsperger, Christian H. Back, Andreas Vaterlaus, Rolf Allenspach, and Wolfgang Weber
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Orientation (vector space) ,Magnetic anisotropy ,Magnetization ,Materials science ,Adsorption ,Condensed matter physics ,Plane (geometry) ,Substrate (electronics) ,Epitaxy ,Anisotropy - Abstract
We report a striking sensitivity of the easy magnetization axis in epitaxial Co films upon adsorption of submonolayers of Cu, Ag, Fe, and O if the Cu substrate is a stepped surface slightly miscut from the (100) orientation. All adsorbates cause a switch of the easy axis by 90\ifmmode^\circ\else\textdegree\fi{} within the plane. The key role of this switching phenomenon is played by the atoms at the step sites and their influence on the magnetic surface anisotropy.
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- 1995
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383. Probing oscillatory exchange coupling with a paramagnet
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A. Bischof, Wolfgang Weber, Christian H. Back, Rolf Allenspach, and Danilo Pescia
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Paramagnetism ,Coupling (physics) ,Materials science ,Condensed matter physics ,Magnetic dipole ,Electron magnetic dipole moment ,Magnetic susceptibility - Published
- 1995
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384. MONSUN A Distributed Manipulator Control System Utilizing Network Technology
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Helmut Breitwieser and Wolfgang Weber
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Engineering ,business.industry ,Application protocol ,Control system ,Human–machine interface ,Control engineering ,Architecture ,Help giving ,business ,Open system (systems theory) - Abstract
The paper presents a philosophy, an architecture and an implementation of a distributed manipulator control system whereby the controllers are to be interconnected by standard LAN-means. MONSUN focusses on manual control in the sense of telepresence systems but also includes semiautonomous operation modes. The application protocols are of prime importance for MONSUN to be an open system. An important finding is that a motorized master arm is of significant help giving natural cues for the limits of the actual working envelope.
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- 1995
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385. Die Bande des Reca Kelmendi : Jugendroman
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Wolfgang Weber and Wolfgang Weber
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Jonas ist genervt: von seiner Mutter, von seiner Schule und von seinen Lehrern. Er macht mit seinen Freunden nicht nur seine Hauptschule, sondern eine ganze norddeutsche Kleinstadt unsicher. Sein neuer Freund, Cenan Kelmendi, der stets fröhliche, aber auch hitzköpfige stellvertretende Sprecher der chaotischen 8 b weiß, wie man sich durchsetzt. Cenans älterer Bruder ist der stadtbekannte Reca, einst Schrecken aller Lehrer und Oberhaupt der Familien-'Bande'Kelmendi, die mit geheimnisvollen Vorbereitungen zu einem großen Coup beschäftigt ist.
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- 2011
386. Computer-Based Assessment: A NATO Survey
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Paul Van Raay, Wolfgang Weber, Agnés Kokorian, François Lescreve, Clessen J. Martin, and Eugene Burke
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Engineering management ,Military personnel ,Operations research ,Order (business) ,Management of Technology and Innovation ,Strategy and Management ,Computer based ,Psychology ,General Business, Management and Accounting ,General Psychology ,Applied Psychology - Abstract
The purpose of this paper is to provide a brief summary of developments in NATO nations in order to bring these developments to a wider audience. The basis of the survey provided is the information collated by NATO Research Study Group 15 Computer-Based Assessment of Military Personnel as given in its report to NATO Headquarters in 1993.
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- 1995
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387. Species-conserved reconfigurations of brain network topology induced by ketamine
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Michael Spedding, Esther Schenker, Celine Risterucci, Wolfgang Weber-Fahr, Urs Braun, C Clemm von Hohenberg, Oliver Grimm, Alexander Sartorius, Heike Tost, Natalia Gass, Janina I. Schweiger, Adam J. Schwarz, Andreas Meyer-Lindenberg, Zhenxiang Zang, and Robert Becker
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Adult ,Male ,0301 basic medicine ,Network science ,Topology ,Rats, Sprague-Dawley ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Double-Blind Method ,medicine ,Animals ,Humans ,Ketamine ,Biological Psychiatry ,Cross-Over Studies ,Drug discovery ,Brain ,medicine.disease ,Phenotype ,Rats ,Psychiatry and Mental health ,030104 developmental biology ,Schizophrenia ,Behavioral medicine ,Antidepressant ,Female ,Original Article ,Psychopharmacology ,Psychology ,Excitatory Amino Acid Antagonists ,Neuroscience ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Species-conserved (intermediate) phenotypes that can be quantified and compared across species offer important advantages for translational research and drug discovery. Here, we investigate the utility of network science methods to assess the pharmacological alterations of the large-scale architecture of brain networks in rats and humans. In a double-blind, placebo-controlled, cross-over study in humans and a placebo-controlled two-group study in rats, we demonstrate that the application of ketamine leads to a topological reconfiguration of large-scale brain networks towards less-integrated and more-segregated information processing in both the species. As these alterations are opposed to those commonly observed in patients suffering from depression, they might indicate systems-level correlates of the antidepressant effect of ketamine.
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- 2016
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388. Corrigendum to 'Haloperidol challenge in healthy male humans: a functional magnetic resonance imaging study' [Neurosci. Lett. 340 (3) (2003) 193–196]
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Sabine Klein, Wolfgang Weber-Fahr, Dieter F. Braus, Heike Tost, Fabian Höhn, and Stefanie Brassen
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Text mining ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,Haloperidol ,medicine ,Functional magnetic resonance imaging ,business ,Neuroscience ,medicine.drug - Published
- 2016
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389. A phase I/IIa trial of prostate specific membrane antigen (PSMA) positron emission tomography (PET) imaging with 89Zr-Df-IAB2M in metastatic prostate cancer (PCa)
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Daniel C. Danila, Steven M. Larson, Susan F. Slovin, Michael J. Morris, Joseph A. O' Donoghue, Victor E. Reuter, Danny F. Martinez, Jason S. Lewis, Jorge A. Carrasquillo, Neeta Pandit-Taskar, Serge K. Lyashchenko, Howard I. Scher, Jeremy C. Durack, Nicole Andrea Parada, Anna M. Wu, Shutian Ruan, Wolfgang Weber, and Jennifer Keppler
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Cancer Research ,medicine.diagnostic_test ,business.industry ,Pet imaging ,Disease distribution ,medicine.disease ,030218 nuclear medicine & medical imaging ,Lesion ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Oncology ,Bone scintigraphy ,Positron emission tomography ,030220 oncology & carcinogenesis ,Biopsy ,Glutamate carboxypeptidase II ,medicine ,medicine.symptom ,Nuclear medicine ,business - Abstract
287 Background: There is a pressing need for improved imaging biomarkers to identify disease distribution and response in both localized and advanced prostate cancer patients. PSMA-directed imaging is undergoing analytic and clinical validation for these contexts of use. IAB2M is an anti-PSMA recombinant minibody (Mb) derived from huJ591. We have previously reported on 28 pts imaged with IAB2M(Pandit-Taskar et al, SNM 2015). Here we report the lesion targeting and uptake (SUV) of the Mb and correlation with pathology of biopsied lesions on the full complement of the 38 pts examined in this trial. Methods: 38 pts with progressive metastatic PCa received escalating amounts of the Mb (16 pts at 10mg, 16 pts at 20mg, 6 pts at 50mg) in a phase I/IIa trial. All pts underwent standard imaging (SI) using CT, bone scintigraphy (BS), FDG PET, followed by imaging with 5 mCi of IAB2M. Whole body PET/CT scans were performed and evaluated for lesion targeting and SUVmax. Biopsy (bx) locations were selected by a consensus panel prioritized on the basis of: IAB2M & FDG positivity, IAB2M & FDG mismatch, and CT or BS positivity & any PET mismatch. Results: A total of 556 lesions (410 bone, 146 soft tissue) in 38 pts were detected by SI or IAB2M. In bone, IAB2M detected 344 lesions (83.9%), CT 209 (51%), BS 211 (51.5%), and FDG 109 (26.6%). For soft tissue, IAB2M detected 119 (81.5%), CT 83 (56.8%), and FDG 79 (54.1%). The SUV for bone lesions ranged from 2.1-60.4 for 10mg Mb, 1.7- 33 in 20mg Mb, and 2.3-17.5 in 50mg Mb. For soft tissue lesions, SUV range was 3.1-45.4, 2.1-20, and 1.9-13.8 respectively. 28 bxs (13 bone, 15 soft tissue) were obtained from 27 pts; 27 bxs were evaluable (1 was non-diagnostic). 20/27 (74.1%) bxs were pos for PCa; 20/24 (83.3%) IAB2M pos lesions were path pos and 3/3 (100%) IAB2M neg lesions were neg on path. All imaging and path correlated (true pos + true neg) in 23/27 (85.2%) bxs. Conclusions: PET imaging with IAB2M has demonstrated higher lesion detection when compared with SI. IAB2M’s high concordance with path suggests pos findings represent bx confirmed PCa. Further studies to examine biochemically recurrent prostate cancer are planned. Clinical trial information: NCT01923727.
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- 2016
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390. Stereotactic ablative radiotherapy for small lung tumors with a moderate dose. Favorable results and low toxicity
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N. Marschner, Felix Heinemann, J. Reusch, Wolfgang Weber, Cornelius F. Waller, V. Duncker-Rohr, Michael Mix, M.-B. Messmer, Felix Momm, Anca-L. Grosu, Ursula Nestle, and V. Prokic
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Oncology ,Male ,medicine.medical_specialty ,Lung Neoplasms ,medicine.medical_treatment ,SABR volatility model ,Radiosurgery ,Multimodal Imaging ,Disease-Free Survival ,Metastasis ,Internal medicine ,Carcinoma, Non-Small-Cell Lung ,Ablative case ,medicine ,Carcinoma ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Neoplasm Staging ,Aged, 80 and over ,Lung ,medicine.diagnostic_test ,business.industry ,Middle Aged ,medicine.disease ,Radiation therapy ,medicine.anatomical_structure ,Positron emission tomography ,Positron-Emission Tomography ,Toxicity ,Female ,Radiology ,business ,Lung Volume Measurements ,Tomography, X-Ray Computed ,Follow-Up Studies - Abstract
Stereotactic ablative body radiotherapy (SBRT, SABR) is being increasingly applied because of its high local efficacy, e.g., for small lung tumors. However, the optimum dosage is still under discussion. Here, we report data on 45 lung lesions [non-small cell lung cancer (NSCLC) or metastases] in 39 patients treated between 2009 and 2010 by SABR. SABR was performed with total doses of 35 Gy (5 fractions) or 37.5 Gy (3 fractions) prescribed to the 60% isodose line encompassing the planning target volume. Three-monthly follow-up CT scans were supplemented by FDG-PET/CT if clinically indicated. The median follow-up was 17 months. Local progression-free survival rates were 90.5% (all patients), 95.0% (NSCLC), and 81.8% (metastases) at 1 year. At 2 years, the respective local progression-free survival rates were 80.5%, 95.0%, and 59.7%. Overall survival rates were 71.1% (all patients), 65.4% (NSCLC), and 83.3% (metastases) at 1 year. Overall survival rates at 2 years were 52.7%, 45.9%, and 66.7%, respectively. Acute side effects were mild. With the moderate dose schedule used, well-tolerated SABR led to favorable local tumor control as in other published series. Standardization in reporting the dose prescription for SABR is needed to allow comparison of different series in order to determine optimum dosage.
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- 2012
391. Effects of normal aging and SCN1A risk-gene expression on brain metabolites: evidence for an association between SCN1A and myo-inositol
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Nuran, Tunc-Skarka, Sandra, Meier, Traute, Demirakca, Markus, Sack, Wolfgang, Weber-Fahr, Wencke, Brusniak, Isabella, Wolf, Franziska, Matthäus, Thomas G, Schulze, Carsten, Diener, and Gabriele, Ende
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Adult ,Aged, 80 and over ,Genetic Markers ,Male ,Aging ,Evidence-Based Medicine ,Magnetic Resonance Spectroscopy ,Brain ,Middle Aged ,Polymorphism, Single Nucleotide ,NAV1.1 Voltage-Gated Sodium Channel ,Young Adult ,Gene Expression Regulation ,Risk Factors ,Animals ,Humans ,Female ,Tissue Distribution ,Genetic Association Studies ,Inositol ,Aged - Abstract
Previously reported MRS findings in the aging brain include lower N-acetylaspartate (NAA) and higher myo-inositol (mI), total creatine (Cr) and choline-containing compound (Cho) concentrations. Alterations in the sodium channel voltage gated type I, alpha subunit SCN1A variant rs10930201 have been reported to be associated with several neurological disorders with cognitive deficits. MRS studies in SCN1A-related diseases have reported striking differences in the mI concentrations between patients and controls. In a study on 'healthy aging', we investigated metabolite spectra in a sample of 83 healthy volunteers and determined their age dependence. We also investigated a potential link between SCN1A and mI. We observed a significantly negative association of NAA (p = 0.004) and significantly positive associations of mI (p ≤ 0.001), Cr (p ≤ 0.001) and Cho (p = 0.034) with age in frontal white matter. The linear association of Cho ends at the age of about 50 years and is followed by an inverted 'U'-shaped curve. Further, mI was higher in C allele carriers of the SCN1A variant rs10930201. Our results corroborated the age-related changes in metabolite concentrations, and found evidence for a link between SCN1A and frontal white matter mI in healthy subjects.
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- 2012
392. Loss of control of alcohol use and severity of alcohol dependence in non-treatment-seeking heavy drinkers are related to lower glutamate in frontal white matter
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Juri Rabinstein, Sabine Vollstädt-Klein, Ulrich Frischknecht, Nuran Tunc-Skarka, Mareen Hoerst, Wolfgang Weber-Fahr, Karl Mann, Svenja Wichert, Gabriele Ende, Derik Hermann, and Traute Demirakca
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Adult ,Male ,medicine.medical_specialty ,Alcohol Drinking ,Medicine (miscellaneous) ,Glutamic Acid ,Alcohol ,Toxicology ,Nerve Fibers, Myelinated ,Severity of Illness Index ,White matter ,chemistry.chemical_compound ,Myelin ,Internal medicine ,Frontal white matter ,medicine ,Choline ,Humans ,Alcohol dependence ,Glutamate receptor ,Middle Aged ,Magnetic Resonance Imaging ,Frontal Lobe ,Diagnostic and Statistical Manual of Mental Disorders ,Psychiatry and Mental health ,Alcoholism ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Frontal lobe ,Female ,Psychology ,Neuroscience ,Biomarkers - Abstract
Background: Thedevelopmentandmaintenanceofalcoholusedisorders(AUD)have beenhypoth-esized to be associated with an imbalance of glutamate (GLU) homeostasis. White matter (WM) loss,especially in anterior brain regions, has been reported in alcohol dependence, which may involvedisturbances in both myelin and axonal integrity. Frontal lobe dysfunction plays an important role inaddiction, because it is suggested to be associated with the loss of control over substance use. Thisstudy investigated magnetic resonance spectroscopy (MRS)-detectable Glu levels in frontal WM ofnon-treatment-seekingheavydrinkersanditsassociationswithAUDsymptoms.Methods: Single-voxel MR spectra optimized for Glu assessment (TE 80 ms) were acquired at 3Tfrom a frontal WM voxel in a group of heavy drinking, non-treatment-seeking subjects in comparisonwithagroupofsubjectswithonlylightalcoholconsumption.Results: The results corroborate previous findings of increased total choline in heavy drinkingsubjects. A negative association of Glu levels with severity of alcohol dependence and especially loss ofcontrolovertimeandamountofalcoholintakewasobserved.Conclusions: In contrast to the rather unspecific rise in choline-containing compounds, low Glu infrontal WM may be specific for the shift from nondependent heavy drinking to dependence and doesnotreflectasimpleeffectoftheamountofalcoholconsumptionalone.Key Words: Alcohol Dependence, Frontal White Matter, Glutamate, Choline-ContainingCompounds, LossofControl,HeavyDrinking.
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- 2012
393. Image quality and data quantification in dopamine transporter SPECT: advantage of 3-dimensional OSEM reconstruction?
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Felix M. Mottaghy, Philipp T. Meyer, Wolfgang Weber, Sabine Hellwig, Wolfgang Schäfer, Michael Mix, Oliver H. Winz, MUMC+: DA BV Medische staf (6), RS: NUTRIM - R1 - Metabolic Syndrome, Beeldvorming, and RS: MHeNs School for Mental Health and Neuroscience
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Male ,Quality Control ,Coefficient of variation ,Caudate nucleus ,Iterative reconstruction ,Imaging, Three-Dimensional ,BINDING ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,NEUROTRANSMISSION ,dopamine transporter ,Aged ,Retrospective Studies ,Dopamine transporter ,Tomography, Emission-Computed, Single-Photon ,Dopamine Plasma Membrane Transport Proteins ,biology ,business.industry ,Putamen ,Binding potential ,General Medicine ,Middle Aged ,I-123-FP-CIT ,Data set ,ITERATIVE RECONSTRUCTION ,SPECT ,biology.protein ,Female ,Tomography ,business ,Nuclear medicine ,Tropanes - Abstract
PURPOSE: Reconstruction of striatal dopamine transporter (DAT) SPECT is commonly done by filtered back projection (FBP). We investigated if image reconstruction by 3-dimensional ordered-subset expectation maximization (3D-OSEM) with resolution recovery, which has recently become available for clinical routine, provides a relevant improvement. METHODS: I-FP-CIT SPECT studies of 18 patients with normal to severely decreased DAT binding were reconstructed by FBP, 2D-OSEM (without resolution recovery), and 3D-OSEM, each with 2 different filter settings, yielding 3 data set pairs of relatively low and high resolution and noise: FBP with seventh-order Butterworth filter [cutoff frequency, 0.36 Nyquist (FBPlow) and 0.45 Nyquist (FBPhigh)] and OSEM with 8 iterations and 8 subsets (2D-/3D-OSEMlow) and 6 iterations and 16 subsets (2D-/3D-OSEMhigh), each with 8-mm Gaussian filtering. Mean regional counts, variability of counts (coefficient of variation), and binding potential (BPND) were assessed by volume-of-interest analyses of the caudate nucleus, the putamen, and the occipital cortex (reference region). RESULTS: On visual inspection, both 2D- and 3D-OSEM-reconstructed images showed an optimal delineation of striatal structures, whereas variability (noise) of nonspecific cortical I-FP-CIT uptake was lowest (most homogenous) with FBPlow, slightly higher with 2D-/3D-OSEMlow, and notably higher for the other methods. Volume-of-interest analyses revealed no significant differences of counts in the occipital reference region in comparison to FBPlow (reference method). In caudate nucleus, counts and, consequently, BPND values increased significantly with FBPhigh (mean BPND change, +5.2%), 2D-OSEMlow/high (+3.7%/+6.2%), and, most notably, 3D-OSEMlow/high (+11.1%/+14.0%). In the putamen, this effect was less pronounced for FBPhigh (+1.8%) and 3D-OSEMlow/high (+5.6%/+6.8%) and failed to reach statistical significance for 2D-OSEMlow/high (-0.2%/+0.8%). Regression analyses indicated excellent correlations of BPND between FBPlow and all other methods (R > 0.97), with the highest regression slopes for 3D-OSEM (1.12-1.16) followed by FBPhigh (1.04-1.06) and then 2D-OSEM (1.01-1.04). The order of the variability of counts in the occipital cortex was as follows: FBPlow (12.5%), 2D-OSEMlow (13.9%), 3D-OSEMlow (14.2%), FBPhigh (15.1%), 2D-OSEMhigh (17.0%), and 3D-OSEMhigh (17.6%). CONCLUSIONS: Three-dimensional OSEM considerably improves DAT SPECT reconstruction by offering an optimal combination of high-resolution delineation of striatal structures, superior recovery of signal and BPND, and sufficiently homogeneous nonspecific tracer uptake of the reference region.
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- 2012
394. Crystal structure of human seminal diferric lactoferrin at 3.4 Angstrom resolution
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Janesh, Kumar, Wolfgang, Weber, Sabine, Münchau, Savita, Yadav, S Bhaskar, Singh, K, Saravanan, M, Paramasivam, Sujata, Sharma, Punit, Kaur, A, Bhushan, A, Srinivasan, Christian, Betzel, and T P, Singh
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Models, Molecular ,Lactoferrin ,Semen ,Iron ,Molecular Sequence Data ,Humans ,Amino Acid Sequence ,Crystallography, X-Ray ,Sequence Analysis ,Protein Structure, Tertiary - Abstract
Lactoferrin was purified from human seminal fluid obtained from the semen bank. The purified samples were saturated with Fe3+ and crystallized by microdialysis method. The crystals belong to orthorhombic space group P21212, with a = 55.9 Angstrom. b = 97.2 Angstrom, c = 156.1 Angstrom and Z = 4. The structure was determined with molecular replacement method and refined to an R factor of 18.7% for all the data to 3.4 Angstrom resolution. The overall structure of seminal lactoferrin is similar to human colostrum lactoferrin. The amino acid sequence of seminal lactoferrin shows that it has one amino acid less than human colostrum lactoferrin and the structure of its N-terminal region is far more ordered than other lactoferrins. The structure of the iron-binding site and its immediate surroundings indicate well defined features.
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- 2012
395. Assessment of striatal dopamine D2/D3 receptor availability with PET and 18F-desmethoxyfallypride: comparison of imaging protocols suited for clinical routine
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P. Reuland, Christian Winkler, Ursula Sahm, Wolfgang Weber, Philipp T. Meyer, Cornelius Weiller, Bernhard Hellwig, Florian Amtage, Timo S. Spehl, and Sabine Hellwig
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Striatal dopamine ,business.industry ,Receptors, Dopamine D2 ,Parkinsonism ,Desmethoxyfallypride ,Receptors, Dopamine D3 ,Binding potential ,Clinical routine ,medicine.disease ,Neostriatum ,Kinetics ,Parkinsonian Disorders ,Positron-Emission Tomography ,Spatial normalization ,Salicylamides ,Radioligand ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,business ,Nuclear medicine ,Receptor ,Aged - Abstract
Assessment of striatal dopamine receptor availability with (18)F-desmethoxyfallypride PET is of high diagnostic utility in parkinsonism. The present study was undertaken to define the optimal clinical scan protocol with regard to quantification accuracy and scan time.Fourteen patients with parkinsonian syndromes underwent (18)F-desmethoxyfallypride PET over 90 min. Volume-of-interest analyses were performed after spatial normalization, with the right and left caudate nuclei and putamina as target regions and the cerebellum as reference region. The estimate of target region binding potential (relative to nondisplaceable radioligand in tissue) (BP(ND)) provided by the 2-step simplified reference tissue model (SRTM2) served as the reference standard. Additional analyses included the multilinear reference tissue model 2 (MRTM2), noninvasive graphical analyses, and single-scan analyses (peak-equilibrium analysis at 35-65 min [PEA]; pseudoequilibrium analysis at 60-90 min [PsEA]).SRTM2 and MRTM2 yielded virtually identical results (mean BP(ND) difference = 0.1% ± 0.5%, r(2) = 1.0). Noninvasive graphical analyses with and without inclusion of the k(2)' term were affected by a small BP(ND) bias (2.5% ± 3.6% and -5.0% ± 6.7%, respectively), although correlations with SRTM2 were still excellent (r(2) = 1.0 and 0.98, respectively). In turn, single-scan analyses suffered from limited precision (PEA, mean BP(ND) bias = 0.7% ± 13.0%, r(2) = 0.90) or a considerable positive bias (PsEA, 19.2% ± 7.1%, r(2) = 0.98). Shortening scan time to 70 and 60 min resulted in an acceptable average BP(ND) change (5% decline) for SRTM2/MRTM2 and graphical analysis with inclusion of the k(2)' term, respectively.Kinetic reference tissue model analyses of (18)F-desmethoxyfallypride PET data offer the least biased results at a well-tolerable scan duration and should thus be pursued whenever possible. Single-scan analyses may be pragmatic alternatives that, however, suffer from a relevant positive bias (PsEA) or limited precision (PEA).
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- 2012
396. Correlation of the genotype of paragangliomas and pheochromocytomas with their metabolic phenotype on 3,4-dihydroxy-6-18F-fluoro-L-phenylalanin PET
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Wolfgang Weber, Jochen Seufert, Dean O. Campbell, Matthias R. Benz, Rebecca A. Dumont, Hartmut P. H. Neumann, H. Christian Rischke, Michael Mix, Jochen Rössler, Thorsten Wiech, and Damian Wild
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Adult ,Male ,medicine.medical_specialty ,endocrine system diseases ,Adolescent ,Genotype ,SDHB ,Adrenal Gland Neoplasms ,Pheochromocytoma ,medicine.disease_cause ,Gastroenterology ,Paraganglioma ,Young Adult ,Germline mutation ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Neurofibromatosis ,Child ,Aged ,Retrospective Studies ,Aged, 80 and over ,Mutation ,Genetic heterogeneity ,business.industry ,Biological Transport ,Middle Aged ,medicine.disease ,Dihydroxyphenylalanine ,Tumor Burden ,Endocrinology ,Phenotype ,Positron-Emission Tomography ,Histopathology ,Female ,SDHD ,business - Abstract
UNLABELLED Paragangliomas and pheochromocytomas are genetically heterogeneous diseases. The purpose of this study was to determine the sensitivity and specificity of PET with 3,4-dihydroxy-6-(18)F-fluoro-L-phenylalanin ((18)F-DOPA) for the detection and staging of pheochromocytomas/paragangliomas. Furthermore, we assessed whether the genotypes of pheochromocytomas and paragangliomas correlate with the uptake of (18)F-DOPA. METHODS We retrospectively analyzed 101 consecutive patients who underwent (18)F-DOPA PET or (18)F-DOPA PET/CT for known or suspected pheochromocytomas or paragangliomas. Maximum (18)F-DOPA tumor uptake was quantified relative to uptake in the liver. RESULTS Histopathology, cross-sectional imaging, and follow-up indicated the presence of paragangliomas and pheochromocytomas in 68 patients and the absence of a tumor in 33 patients. The average (18)F-DOPA uptake by paragangliomas and pheochromocytomas, expressed as a tumor-to-liver ratio, was 5.9 ± 5.2. There was no significant difference in uptake among patients with von Hippel Lindau syndrome (VHL; n = 19), succinate dehydrogenase B-D mutation (n = 21), neurofibromatosis type 1 (n = 1), RET (n = 1), no germline mutation (n = 20), or unknown mutation status (n = 6) (P = 0.84). All 8 patients with an SDHD mutation were true-positive on (18)F-DOPA PET. There were 2 cases of false-negative results each in the group with SDHB (2/12) and VHL mutations (2/19) and 1 false-negative result in the subgroup of patients with unknown mutation status (1/6). Overall, (18)F-DOPA PET yielded a sensitivity of 93% and a specificity of 88% for the detection of paragangliomas and pheochromocytomas on a patient basis (positive and negative predictive value, 94% and 85%, respectively). CONCLUSION (18)F-DOPA PET is a sensitive and specific imaging modality for the detection and staging of pheochromocytomas and paragangliomas in different genotypes, including VHL-, SDHB-, and SDHD-mutation carriers, and in patients with no germline mutation.
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- 2012
397. Zu Snorri Sturlusons Ausschöpfung der Skaldendichtung als historischer Quelle: Glymdrápa Str. 8 als methodologisches Problem
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Gerd Wolfgang Weber
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- 2012
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398. In vivo imaging of folate receptor positive tumor xenografts using novel 68Ga-NODAGA-folate conjugates
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Marc Port, Maria-Luisa Tamma, Wolfgang Weber, Melpomeni Fani, Isabelle Raynal, Helmut R. Maecke, Guillaume Nicolas, Elisabeth Lasri, and Christelle Medina
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Pharmaceutical Science ,Mice, Nude ,Gallium Radioisotopes ,Acetates ,Heterocyclic Compounds, 1-Ring ,Mice ,Folic Acid ,Heterocyclic Compounds ,Cell Line, Tumor ,Drug Discovery ,Organometallic Compounds ,Animals ,Humans ,Chemistry ,Folate Receptors, GPI-Anchored ,Nasopharyngeal Neoplasms ,Pet imaging ,Biochemistry ,Folic acid ,Cell culture ,Folate receptor ,Positron-Emission Tomography ,Molecular targets ,Cancer research ,Molecular Medicine ,Female ,Preclinical imaging ,Conjugate - Abstract
The overexpression of the folate receptor (FR) in a variety of malignant tumors, along with its limited expression in healthy tissues, makes it an attractive tumor-specific molecular target. Noninvasive imaging of FR using radiolabeled folate derivatives is therefore highly desirable. Given the advantages of positron emission tomography (PET) and the convenience of (68)Ga production, the aim of our study was to develop a new (68)Ga-folate-based radiotracer for clinical application. The chelator 1,4,7-triazacyclononane,1-glutaric acid-4,7-acetic acid (NODAGA) was conjugated to folic acid and to 5,8-dideazafolic acid using 1,2-diaminoethane as a spacer, resulting in two novel conjugates, namely, P3246 and P3238, respectively. Both conjugates were labeled with (68/67)Ga. In vitro internalization, efflux, and saturation binding studies were performed using the FR-positive KB cell line. Biodistribution and small-animal PET imaging studies were performed in nude mice bearing subcutaneous KB xenografts. Both conjugates were labeled with (68)Ga at room temperature within 10 min in labeling yields95% and specific activity ~30 GBq/μmol. The K(d) values of (68/67)Ga-P3246 (5.61 ± 0.96 nM) and (68/67)Ga-P3238 (7.21 ± 2.46 nM) showed high affinity for the FR. (68/67)Ga-P3246 showed higher cell-associated uptake in vitro than (68/67)Ga-P3238 (approximately 72 and 60% at 4 h, respectively, P0.01), while both radiotracers exhibited similar cellular retention up to 4 h (approximately 76 and 71%, respectively). Their biodistribution profile is characterized by high tumor uptake, fast blood clearance, low hepatobiliary excretion, and almost negligible background. Tumor uptake was already high at 1 h for both (68)Ga-P3246 and (68)Ga-P3238 (16.56 ± 3.67 and 10.95 ± 2.12% IA/g, respectively, P0.05) and remained at about the same level up to 4 h. Radioactivity also accumulated in the FR-positive organs, such as kidneys (91.52 ± 21.05 and 62.26 ± 14.32% IA/g, respectively, 1 h pi) and salivary glands (9.05 ± 2.03 and 10.39 ± 1.19% IA/g, respectively, 1 h pi). The specificity of the radiotracers for the FR was confirmed by blocking experiments where tumor uptake was reduced by more than 85%, while the uptake in the kidneys and the salivary glands was reduced by more than 90%. Reduction of the kidney uptake was achieved by administration of the antifolate pemetrexed 1 h prior to the injection of the radiotracers, which resulted in an improvement of tumor-to-kidney ratios by more than a factor of 3. In line with the biodistribution results, small-animal PET images showed high uptake in the kidneys, clear visualization of the tumor, accumulation of radioactivity in the salivary glands, and no uptake in the gastrointestinal tract. (68)Ga-P3246 and (68)Ga-P3238 showed very high tumor-to-background contrast in PET images; however, the tumor-to-kidney ratio remained low. The new radiotracers, especially (68)Ga-P3246, are promising as PET imaging probes for clinical application due to their facile preparation and improved in vivo profile as compared to the other folate-based PET radiotracers.
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- 2012
399. [18F]desmethoxyfallypride as a novel PET radiotracer for quantitative in vivo dopamine D2/D3 receptor imaging in rat models of neurodegenerative diseases
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Guido Nikkhah, Joanna Garcia, Máté D. Döbrössy, Wolfgang Weber, Stefanie Klein, Friederike Braun, Philipp T. Meyer, and Karl-Josef Langen
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Cancer Research ,Pathology ,medicine.medical_specialty ,Parkinson's disease ,chemistry.chemical_compound ,In vivo ,Dopamine receptor D3 ,Dopamine receptor D2 ,Salicylamides ,medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,Radioactive Tracers ,Medial forebrain bundle ,Chemistry ,Receptors, Dopamine D2 ,Neurodegeneration ,Desmethoxyfallypride ,Receptors, Dopamine D3 ,Parkinson Disease ,medicine.disease ,Rats ,Disease Models, Animal ,Huntington Disease ,Raclopride ,Positron-Emission Tomography ,Molecular Medicine ,Quinolinic acid - Abstract
Introduction [ 18 F]desmethoxyfallypride ([ 18 F]DMFP) is a promising tracer for longitudinal assessment of striatal dopamine D2/D3-receptor (D2R) availability by positron emission tomography (PET) in small animal models. We explored the feasibility of [ 18 F]DMFP-PET to image D2R availability in rat models of Huntington's (HD) and Parkinson's disease (PD). Methods Animals received either unilateral intrastriatal quinolinic acid lesions or medial forebrain bundle injections of 6-OHDA to produce the loss of striatal projection neurones or deplete the striatal dopamine, corresponding to established animal models for HD and PD, respectively. Three weeks after lesioning, PET scans were acquired on a microPET Focus 120 system following the tail vein injection of [ 18 F]DMFP. Results [ 18 F]DMFP-PET clearly visualized lesion induced decreases and increases of D2R availability. In vivo estimates of D2R binding and changes thereof gained by pharmacokinetic analyses correlated significantly with D2R density and its change provided by in vitro [ 3 H]raclopride-autoradiography. Conclusions In conclusion, [ 18 F]DMFP-PET is a suitable method for in vivo D2R-assessment in preclinical research, e.g for monitoring cell-based therapies.
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- 2012
400. 18F-FDG-PET/CT Imaging as an early survival predictor in patients with primary high-grade soft tissue sarcomas undergoing neoadjuvant therapy
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Fritz C. Eilber, Tibor Schuster, Wolfgang Weber, Jeffrey J. Eckardt, Matthias R. Benz, Ken Herrmann, Martin Allen-Auerbach, Michael E. Phelps, Johannes Czernin, William D. Tap, and Sarah M. Dry
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Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Surgical margin ,Time Factors ,medicine.medical_treatment ,Urology ,Kaplan-Meier Estimate ,Multimodal Imaging ,Article ,Young Adult ,Fluorodeoxyglucose F18 ,Antineoplastic Combined Chemotherapy Protocols ,Outcome Assessment, Health Care ,medicine ,Humans ,Prospective Studies ,Survival analysis ,Neoadjuvant therapy ,Aged ,Aged, 80 and over ,business.industry ,Soft tissue sarcoma ,Cancer ,Sarcoma ,Middle Aged ,medicine.disease ,Prognosis ,Confidence interval ,Neoadjuvant Therapy ,Oncology ,Positron-Emission Tomography ,Multivariate Analysis ,Biomarker (medicine) ,Histopathology ,Female ,Radiopharmaceuticals ,Nuclear medicine ,business ,Tomography, X-Ray Computed ,Follow-Up Studies - Abstract
Purpose: Neoadjuvant therapy is associated with considerable toxicity and limited survival benefits in patients with soft tissue sarcoma (STS). We prospectively evaluated whether 2[18F]fluoro-2-deoxy-d-glucose (18F-FDG)-PET/computed tomographic (CT) imaging after the initial cycle of neoadjuvant therapy could predict overall survival in these patients. Experimental Design: Thirty-nine patients underwent 18F-FDG-PET/CT before and after one cycle of neoadjuvant therapy. Fifty-six patients underwent end-of-treatment PET. Overall survival was, among others, correlated with changes of SUVpeak and histopathology. Results: One-, two-, and five-year survival rates were 95% ± 3.0%, 86% ± 4.6%, and 68% ± 6.6%, respectively. Median time to death was 30.9 months (mean, 27.7; range, 6.9–50.1). Optimal cutoff values for early and late decreases in SUVpeak (26% and 57%, respectively) were significant predictors of survival in univariate survival analysis [P = 0.041; HR, 0.27; 95% confidence interval (CI), 0.08–0.95 and P = 0.045; HR, 0.31; 95% CI, 0.10–0.98]. Seven of 15 early PET nonresponders but only four of 24 early PET responders died during follow-up (P = 0.068). The only other significant survival predictor was surgical margin positivity (P = 0.041; HR, 3.31; 95% CI, 1.05–10.42). By multivariable analysis, early metabolic response (P = 0.016) and positivity of surgical margins (P = 0.036) remained significant survival predictors. Conclusion: 18F-FDG-PET predicted survival after the initial cycle of neoadjuvant chemotherapy in patients with STS and can potentially serve as an intermediate endpoint biomarker in clinical research and patient care. Clin Cancer Res; 18(7); 2024–31. ©2012 AACR.
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- 2012
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