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Taylor D, Donovan L, Choi J, Kim R, Schwarz U, Wilson A. A174 A NOVEL MECHANISM OF CROHN’S DISEASE SEVERITY IN WOMEN: EVALUATING THE IMPACT OF AN ESTROGEN-FARNESOID X RECEPTOR INTERACTION ON INTESTINAL BARRIER FUNCTION. J Can Assoc Gastroenterol 2023. [PMCID: PMC9991304 DOI: 10.1093/jcag/gwac036.174] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 03/09/2023] Open
Abstract
Background Crohn’s disease (CD) is associated with deficits in intestinal barrier function. Activation of bile acid-sensing nuclear receptor Farnesoid X receptor (NR1H4, FXR) is associated with protective effects against reduced intestinal barrier function; namely through promoting tight junction complex genes (TJCGs) and reducing expression of inflammatory cytokines. The FXR -1G>T variant is associated with decreased FXR activation and increased risk of, and early progression to, CD-related surgery in females only. It is hypothesized an estrogen-FXR interaction is mediating this effect. Purpose We aimed to assess the combined effect of estrogen and FXR genetic variation on intestinal barrier function using a cell-based model and its impact in a clinical cohort. Method Caco-2 cells were characterized for expression of TJCGs (zonula occludens-1, occludin, junctional adhesion molecule A, and claudin-1 and claudin-2), FXR, and nuclear estrogen receptors (ERα, ERβ) by qPCR. The influence of FXR activation on TJCGs was characterized by incubation of Caco-2 cells with chenodeoxycholic acid (CDCA). FXR-knockout stable Caco-2 line was developed using CRISPR-Cas9 methods and verified by qPCR and genotyping. The effect of estradiol on expression of TJCGs in FXR-knockout and wildtype Caco-2 cell monolayers was compared by qPCR. Future experiments include comparison of FXR-knockout and wildtype monolayer permeability with estrogen exposure by transwell permeability assay. The effect of FXR genotype and exogenous estrogen CD severity (surgery, hospitalization, fistulizing disease) was evaluated in our female cohort by multivariate analysis. Result(s) Increased expression of TJCGs was seen in native Caco-2 monolayers incubated with CDCA. FXR-knockout cell line was then successfully created and confirmed. FXR-knockout cells showed decreased expression of TJCGs with the exception of zonula occludens-1. Estradiol exposure resulted in a dose-dependent decline in TJCGs expression in the wildtype Caco-2 cell line, however this effect was lost in the FXR-knockout cell line. Preliminary analysis of patient cohort data (n=359) showed exogenous estrogen was associated with lower surgery risk (OR = 0.603, 95% CI= 0.373–0.964, p < 0.05; Fischer’s exact test) and trended towards decreasing fistulizing disease risk in a multiple logistic regression model which included FXR genotype. The association of FXR genotype with increased surgery risk was also confirmed in this logistic regression model. Conclusion(s) Herein, we show that FXR activity affects expression of TJCGs, and this effect is attenuated by estrogen interactions. Our patient cohort preliminary analysis confirmed an increased CD severity risk associated with FXR genotype and demonstrated a trend of decreasing CD severity with exogenous estrogen exposure. Further studies will assess the mechanisms by which FXR and estrogen interact to influence intestinal permeability. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding; Department of Medicine, Western University Disclosure of Interest D. Taylor: None Declared, L. Donovan: None Declared, J. Choi: None Declared, R. Kim: None Declared, U. Schwarz: None Declared, A. Wilson Consultant of: Consulting fees from Fresenius Kabi, Speakers bureau of: Speaking fees from Takeda and Pfizer
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Affiliation(s)
- D Taylor
- Department of Physiology & Pharmacology
| | - L Donovan
- Schulich School of Medicine & Dentistry
| | - J Choi
- Department of Physiology & Pharmacology
| | - R Kim
- Department of Medicine, Western University, London, Canada
| | - U Schwarz
- Department of Physiology & Pharmacology
| | - A Wilson
- Department of Medicine, Western University, London, Canada
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Mydeen K, Jesche A, Meier-Kirchner K, Schwarz U, Geibel C, Rosner H, Nicklas M. Electron Doping of the Iron-Arsenide Superconductor CeFeAsO Controlled by Hydrostatic Pressure. Phys Rev Lett 2020; 125:207001. [PMID: 33258641 DOI: 10.1103/physrevlett.125.207001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/25/2020] [Accepted: 10/14/2020] [Indexed: 06/12/2023]
Abstract
In the iron-pnictide material CeFeAsO not only the Fe moments, but also the local 4f moments of the Ce order antiferromagnetically at low temperatures. We elucidate on the peculiar role of the Ce on the emergence of superconductivity. While application of pressure suppresses the iron SDW ordering temperature monotonously up to 4 GPa, the Ce-4f magnetism is stabilized until both types of magnetic orders disappear abruptly and a narrow SC dome develops. With further increasing pressure characteristics of a Kondo-lattice system become more and more apparent in the electrical resistivity. This suggests a connection of the emergence of superconductivity with the extinction of the magnetic order and the onset of Kondo screening of the Ce-4f moments.
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Affiliation(s)
- K Mydeen
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - A Jesche
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany
| | - K Meier-Kirchner
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - U Schwarz
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - C Geibel
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - H Rosner
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
| | - M Nicklas
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden
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Abstract
BACKGROUND Chikungunya fever is a globally spreading mosquito-borne disease that shows an unexpected neurovirulence. Even though the neurological complications have been a major cause of intensive care unit admission and death, to date, there is no systematic analysis of their spectrum available. OBJECTIVE To review evidence of neurological manifestations in Chikungunya fever and map their epidemiology, clinical spectrum, pathomechanisms, diagnostics, therapies and outcomes. METHODS Case report and systematic review of the literature followed established guidelines. All cases found were assessed using a 5-step clinical diagnostic algorithm assigning categories A-C, category A representing the highest level of quality. Only A and B cases were considered for further analysis. After general analysis, cases were clustered according to geospatial criteria for subgroup analysis. RESULTS Thirty-six of 1196 studies were included, yielding 130 cases. Nine were ranked as category A (diagnosis of Neuro-Chikungunya probable), 55 as B (plausible), and 51 as C (disputable). In 15 cases, alternative diagnoses were more likely. Patient age distribution was bimodal with a mean of 49 years and a second peak in infants. Fifty percent of the cases occurred in patients <45 years with no reported comorbidity. Frequent diagnoses were encephalitis, optic neuropathy, neuroretinitis, and Guillain-Barré syndrome. Neurologic conditions showing characteristics of a direct viral pathomechanism showed a peak in infants and a second one in elder patients, and complications and neurologic sequelae were more frequent in these groups. Autoimmune-mediated conditions appeared mainly in patients over 20 years and tended to show longer latencies and better outcomes. Geospatial subgrouping of case reports from either India or Réunion revealed diverging phenotypic trends (Réunion: 88% direct viral vs. India: 81% autoimmune). CONCLUSIONS Direct viral forms of Neuro-Chikungunya seem to occur particularly in infants and elderly patients, while autoimmune forms have to be also considered in middle-aged, previously healthy patients, especially after an asymptomatic interval. This knowledge will help to identify future Neuro-Chikungunya cases and to improve outcome especially in autoimmune-mediated conditions. The genetics of Chikungunya virus might play a key role in determining the course of neuropathogenesis. With further research, this could prove diagnostically significant.
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Affiliation(s)
- T Cerny
- Neurointensive Care Unit, University Hospital Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland
| | - M Schwarz
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - U Schwarz
- Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - J Lemant
- Intensive Care Unit, CHU de la Réunion, Saint Pierre, Réunion, France
| | - P Gérardin
- INSERM CIC 1410, CHU de la Réunion, Saint Pierre, Réunion, France.,CNRS 9192, INSERM U1187, IRD 249, CHU Réunion, Unité Mixte 134 Processus Infectieux en Milieu Insulaire Tropical (PIMIT), CYROI, Université de La Réunion, Sainte-Clotilde, Réunion, France
| | - E Keller
- Neurointensive Care Unit, University Hospital Zurich, Frauenklinikstrasse 10, 8091, Zurich, Switzerland.
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Mydeen K, Kasinathan D, Koz C, Rößler S, Rößler UK, Hanfland M, Tsirlin AA, Schwarz U, Wirth S, Rosner H, Nicklas M. Pressure-Induced Ferromagnetism due to an Anisotropic Electronic Topological Transition in Fe_{1.08}Te. Phys Rev Lett 2017; 119:227003. [PMID: 29286759 DOI: 10.1103/physrevlett.119.227003] [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: 03/09/2017] [Indexed: 06/07/2023]
Abstract
A rapid and anisotropic modification of the Fermi-surface shape can be associated with abrupt changes in crystalline lattice geometry or in the magnetic state of a material. We show that such an electronic topological transition is at the basis of the formation of an unusual pressure-induced tetragonal ferromagnetic phase in Fe_{1.08}Te. Around 2 GPa, the orthorhombic and incommensurate antiferromagnetic ground state of Fe_{1.08}Te is transformed upon increasing pressure into a tetragonal ferromagnetic state via a conventional first-order transition. On the other hand, an isostructural transition takes place from the paramagnetic high-temperature state into the ferromagnetic phase as a rare case of a "type-0" transformation with anisotropic properties. Electronic-structure calculations in combination with electrical resistivity, magnetization, and x-ray diffraction experiments show that the electronic system of Fe_{1.08}Te is instable with respect to profound topological transitions that can drive fundamental changes of the lattice anisotropy and the associated magnetic order.
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Affiliation(s)
- K Mydeen
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - D Kasinathan
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - C Koz
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - S Rößler
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - U K Rößler
- Leibniz-Institut für Festkörper- und Werkstoffforschung IFW, Helmholtz Straße 20, 01171 Dresden, Germany
| | - M Hanfland
- ESRF, BP 220, F-38043 Grenoble Cedex 9, France
| | - A A Tsirlin
- Experimental Physics VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany
| | - U Schwarz
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - S Wirth
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - H Rosner
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - M Nicklas
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
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Materne P, Koz C, Rössler UK, Doerr M, Goltz T, Klauss HH, Schwarz U, Wirth S, Rössler S. Solitonic Spin-Liquid State Due to the Violation of the Lifshitz Condition in Fe(1+y)Te. Phys Rev Lett 2015; 115:177203. [PMID: 26551139 DOI: 10.1103/physrevlett.115.177203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Indexed: 06/05/2023]
Abstract
A combination of phenomenological analysis and Mössbauer spectroscopy experiments on the tetragonal Fe(1+y)Te system indicates that the magnetic ordering transition in compounds with higher Fe excess, y≥0.11, is unconventional. Experimentally, a liquidlike magnetic precursor with quasistatic spin order is found from significantly broadened Mössbauer spectra at temperatures above the antiferromagnetic transition. The incommensurate spin-density wave order in Fe(1+y)Te is described by a magnetic free energy that violates the weak Lifshitz condition in the Landau theory of second-order transitions. The presence of multiple Lifshitz invariants provides the mechanism to create multidimensional, twisted, and modulated solitonic phases.
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Affiliation(s)
- Ph Materne
- Institut für Festkörperphysik, Technische Universität Dresden, 01062 Dresden, Germany
| | - C Koz
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straß e 40, 01187 Dresden, Germany
| | - U K Rössler
- IFW Dresden, Postfach 270016, 01171 Dresden, Germany
| | - M Doerr
- Institut für Festkörperphysik, Technische Universität Dresden, 01062 Dresden, Germany
| | - T Goltz
- Institut für Festkörperphysik, Technische Universität Dresden, 01062 Dresden, Germany
| | - H H Klauss
- Institut für Festkörperphysik, Technische Universität Dresden, 01062 Dresden, Germany
| | - U Schwarz
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straß e 40, 01187 Dresden, Germany
| | - S Wirth
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straß e 40, 01187 Dresden, Germany
| | - S Rössler
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straß e 40, 01187 Dresden, Germany
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Schmitt KU, Seeger R, Fischer H, Lanz C, Muser M, Walz F, Schwarz U. Reply to: Technical Comment on “Saccadic eye movement performance as an indicator of driving ability in elderly drivers”. Swiss Med Wkly 2015; 145:w14195. [DOI: 10.4414/smw.2015.14195] [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: 11/19/2022] Open
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Gumeniuk R, Schöneich M, Kvashnina KO, Akselrud L, Tsirlin AA, Nicklas M, Schnelle W, Janson O, Zheng Q, Curfs C, Burkhardt U, Schwarz U, Leithe-Jasper A. Intermetallic germanides with non-centrosymmetric structures derived from the Yb3Rh4Sn13 type. Dalton Trans 2015; 44:5638-51. [PMID: 25705863 DOI: 10.1039/c4dt03155e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [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
New germanides with composition RE3Pt4Ge13 (RE = Y, Pr, Sm, Gd, Tb, Tm) have been prepared by high-pressure, high-temperature synthesis. Their crystal structures have been refined, and the relationship of this new rhombohedral and monoclinic structure types with the primitive cubic Yb3Rh4Sn13 prototype is discussed. Band structure calculations within density functional theory confirm the distorted rhombohedral and monoclinic structural arrangements to be energetically more favorable than the simple cubic one. X-ray absorption spectroscopy and magnetic susceptibility measurements indicate that the RE-atoms are in the +3 oxidation state in all studied compounds.
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Affiliation(s)
- R Gumeniuk
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
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Tencé S, Janson O, Krellner C, Rosner H, Schwarz U, Grin Y, Steglich F. CoBi3--the first binary compound of cobalt with bismuth: high-pressure synthesis and superconductivity. J Phys Condens Matter 2014; 26:395701. [PMID: 25204566 DOI: 10.1088/0953-8984/26/39/395701] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The first compound in the cobalt bismuth system was synthesized by high-pressure high-temperature synthesis at 5 GPa and 450 °C. CoBi3 crystallizes in space group Pnma (no. 62) with lattice parameters of a = 8.8464(7) Å, b = 4.0697(4) Å and c = 11.5604(9) Å adopting a NiBi3-type crystal structure. CoBi3 undergoes a superconducting transition at Tc = 0.48(3) K as evidenced by electrical-resistivity and specific-heat measurements. Based on the anomaly of the specific heat at Tc and considering the estimated electron-phonon coupling, the new Bi-rich compound can be classified as a Bardeen-Cooper-Schrieffer-type superconductor with weak electron-phonon coupling. Density-functional theory calculations disclose a sizable influence of the spin-orbit coupling to the valence states and proximity to a magnetic instability, which accounts for a significantly enhanced Sommerfeld coefficient.
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Affiliation(s)
- S Tencé
- CNRS, ICMCB, UPR 9048, F-33600 Pessac, France. Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac, France
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Davis RF, Gehrke T, Linthicum K, Rajagopal P, Roskowski A, Zheleva T, Preble EA, Zorman C, Mehregany M, Schwarz U, Schuck J, Grober R. Review of Pendeo-Epitaxial Growth and Characterization of Thin Films of GaN and AlGaN Alloys on 6H-SiC(0001) and Si(111) Substrates. ACTA ACUST UNITED AC 2014. [DOI: 10.1557/s1092578300000260] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Discrete and coalesced monocrystalline GaN and AlxGa1−xN layers grown via pendeo-epitaxy (PE) originated from side walls of GaN seed stripes with and without SiNx top masks have been grown via organometallic vapor phase deposition on GaN/AlN/6H-SiC(0001) and GaN(0001)/AlN(0001)/3C-SiC(111)/Si(111) substrates. Scanning and transmission electron microscopies were used to evaluate the external microstructures and the distribution of dislocations, respectively. The dislocation density in the laterally grown sidewall regions and in the regions grown over the SiNx masks was reduced by at least five orders of magnitude relative to the initial GaN seed layers. Tilting of 0.2° in the coalesced GaN epilayers grown over the SiNx masks was determined via X-ray and selected area diffraction; however, tilting was not observed in the material suspended above the SiC substrate and that grown on unmasked stripes. A strong, low-temperature photoluminescence band-edge peak at ~3.45 eV with a FWHM of <300 µeV was determined on the overgrowth material grown on the silicon carbide substrates. The band-edge in the GaN grown on silicon substrates was shifted to a lower energy by 10 meV, indicative of a greater tensile stress.
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Abstract
Two stages in murein-biosynthesis — first, the partial degradation of the preexistent murein and second, the neosynthesis immediately following it under normal conditions — can be separated by DAP *-starvation of the DAP-dependent mutant of E. coli W 173-25. In order to investigate the function of mureinhydrolases in murein-biosynthesis, the degradation of murein in growing cells has been studied using a new method. Evidence is presented which indicates that a muramylendopeptidase plays a major role in the process. The activity of this enzyme is revealed by a conversion of the cells into spheroplasts upon DAP-starvation.
A hypothesis concerning the insertion of new murein moieties due to transpeptidation by this enzyme is discussed.
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Affiliation(s)
- W. Leutgeb
- Max-Planck-Institut für Biologie, Tübingen
| | - U. Schwarz
- Max-Planck-Institut für Biologie, Tübingen
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Odermatt B, Schwarz U, Zimmermann R, Krafft A. Opsoklonus-Myoklonus-Ataxie Syndrom in der Schwangerschaft – eine Rarität! Z Geburtshilfe Neonatol 2013. [DOI: 10.1055/s-0033-1361311] [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: 10/26/2022]
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Imbach LL, Kuhn F, Zumsteg V, Schwarz U. Picture story: Herniated brain causing generalised seizures. Assoc Med J 2012. [DOI: 10.1136/bmj.e7652] [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: 11/04/2022]
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Werheit H, Filipov V, Shitsevalova N, Armbrüster M, Schwarz U. Isotopic phonon effects in LaB6-LaB6 do not possess cubic symmetry and show a non-random isotope distribution. J Phys Condens Matter 2012; 24:385405. [PMID: 22945638 DOI: 10.1088/0953-8984/24/38/385405] [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: 06/01/2023]
Abstract
The isotopic phonon effects in LaB(6) are investigated on the Raman spectra of a series of high-quality single crystals with systematically varied contents of (10)B and (11)B isotopes. A detailed group theoretical analysis enlightens the correlation between distortions of the B(6) octahedra and the splitting or broadening of phonon modes. It is evident that LaB(6) does not have cubic symmetry as assumed so far. A further symmetry reduction of the B(6) octahedra occurs in isotopically mixed crystals. There, the distribution of isotopes is not random as commonly assumed; the probability of associating equal isotopes increases with their mass decreasing.
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Affiliation(s)
- H Werheit
- Institute of Physics, University Duisburg-Essen, Duisburg, Germany.
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Nern C, Bellut D, Husain N, Pangalu A, Schwarz U, Valavanis A. Fatal cerebral venous air embolism during endoscopic retrograde cholangiopancreatography-case report and review of the literature. Clin Neuroradiol 2012; 22:371-4. [PMID: 22689221 DOI: 10.1007/s00062-012-0155-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Accepted: 05/15/2012] [Indexed: 12/17/2022]
Affiliation(s)
- C Nern
- Department of Neuroradiology, University Hospital Zurich, Switzerland.
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Werheit H, Filipov V, Kuhlmann U, Schwarz U, Armbrüster M, Antadze M. Isotopic phonon effects in β-rhombohedral boron--non-statistical isotope distribution. J Phys Condens Matter 2012; 24:175401. [PMID: 22469660 DOI: 10.1088/0953-8984/24/17/175401] [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
On the basis of the spectra of IR- and Raman-active phonons, the isotopic phonon effects in β-rhombohedral boron are analysed for polycrystalline (10)B- and (11)B-enriched samples of different origin and high-purity (nat)B single crystals. Intra- and inter-icosahedral B-B vibrations are harmonic, hence meeting the virtual crystal approximation (VCA) requirements. Deviations from the phonon shift expected according to the VCA are attributed to the anharmonic share of the lattice vibrations. In the case of icosahedral vibrations, the agreement with calculations on α-rhombohedral boron by Shirai and Katayama-Yoshida is quite satisfactory. Phonon shifts due to isotopic disorder in (nat)B are separated and determined. Some phonon frequencies are sensitive to impurities. The isotopic phonon effects yield valuable specific information on the nature of the different phonon modes. The occupation of regular boron sites by isotopes deviates significantly from the random distribution.
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Affiliation(s)
- H Werheit
- Institute of Physics, University Duisburg-Essen, Campus Duisburg, 47048 Duisburg, Germany.
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Werheit H, Filipov V, Shirai K, Dekura H, Shitsevalova N, Schwarz U, Armbrüster M. Raman scattering and isotopic phonon effects in dodecaborides. J Phys Condens Matter 2011; 23:065403. [PMID: 21406928 DOI: 10.1088/0953-8984/23/6/065403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Raman spectra of numerous dodecaborides have been measured on high-quality single crystals at ambient conditions with high spectral resolution and signal-to-noise ratio. Besides the strong Raman-active modes, numerous Raman-inactive modes occur in the spectra, indicating distortions of the structures. Ab initio calculation of the phonon spectra on ZrB(12) excellently agrees with the experimental results. Force constants are theoretically calculated and force parameters are estimated from the Raman frequencies. The influence of the surface range on the Raman spectra is evident. The different isotopic effects (virtual crystal approximation, the polarization effect and the effect of isotopic disorder) on the phonon frequencies are determined, separated and discussed.
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Affiliation(s)
- H Werheit
- Institute of Physics, University Duisburg-Essen, Campus Duisburg, D-47048 Duisburg, Germany.
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Budak K, Iliakis D, Schwarz U, Brunckhorst CB. [Syncope]. Praxis (Bern 1994) 2010; 99:518-530. [PMID: 20449819 DOI: 10.1024/1661-8157/a000139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- K Budak
- Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich
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Werheit H, Filipov V, Schwarz U, Armbrüster M, Leithe-Jasper A, Tanaka T, Shalamberidze SO. On surface Raman scattering and luminescence radiation in boron carbide. J Phys Condens Matter 2010; 22:045401. [PMID: 21386312 DOI: 10.1088/0953-8984/22/4/045401] [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] [Indexed: 05/26/2023]
Abstract
The discrepancy between Raman spectra of boron carbide obtained by Fourier transform Raman and conventional Raman spectrometry is systematically investigated. While at photon energies below the exciton energy (1.560 eV), Raman scattering of bulk phonons of boron carbide occurs, photon energies exceeding the fundamental absorption edge (2.09 eV) evoke additional patterns, which may essentially be attributed to luminescence or to the excitation of Raman-active processes in the surface region. The reason for this is the very high fundamental absorption in boron carbide inducing a very small penetration depth of the exciting laser radiation. Raman excitations essentially restricted to the boron carbide surface region yield spectra which considerably differ from bulk phonon ones, thus indicating structural modifications.
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Affiliation(s)
- H Werheit
- Institute of Physics, University Duisburg-Essen, Duisburg, Germany.
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Abstract
Abstract
Structural properties of the intermetallic compound GdGa2 were investigated under hydrostatic pressures up to 20 GPa using angle dispersive x-ray powder diffraction in combination with the diamond anvil cell technique. At 7.7(5) GPa the onset of a first order phase transition from the AlB2 type structure into a hexagonal high-pressure phase is observed. The transformation is associated with a 2.5 % elongation of the lattice parameter a and an 8 % shortening of c. TB-LMTO bandstructure calculations reveal that the two-dimensional character of the gallium partial structure is preserved in the high-pressure modification.
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Andres M, Krayenbühl PA, Schwarz U. [Differential involuntary muscle movement diagnosis]. Praxis (Bern 1994) 2009; 98:985-994. [PMID: 19739043 DOI: 10.1024/1661-8157.98.18.985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- M Andres
- Klinik und Poliklinik für Innere Medizin, Universitätsspital Zürich, Zürich.
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Lunderstädt J, Schwarz U, Dinish KN. Über Zusammenhänge zwischen dem Zuckerstoffwechsel bei Larven von Gilpinia hercyniae (Hym., Diprionidae) und dem Kohlenhydratgehalt ihrer natürlichen Nahrung, den Nadeln von Fichte (Picea abies Karst)1. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1439-0418.1974.tb03256.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [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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Zaikina JV, Kovnir KA, Burkhardt U, Schnelle W, Haarmann F, Schwarz U, Grin Y, Shevelkov AV. Cationic clathrate I Si(46-x)P(x)Te(y) (6.6(1) < or = y < or = 7.5(1), x < or = 2y): crystal structure, homogeneity range, and physical properties. Inorg Chem 2009; 48:3720-30. [PMID: 19281208 DOI: 10.1021/ic8023887] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new cationic clathrate I Si(46-x)P(x)Te(y) (6.6(1) < or = y < or = 7.5(1), x < or = 2y at 1375 K) was synthesized from the elements and characterized by X-ray powder diffraction, thermal analysis, scanning electron microscopy, wavelength dispersive X-ray spectroscopy (WDXS), neutron powder diffraction, and (31)P NMR spectroscopy. The thermal behaviors of the magnetic susceptibility and resistivity were investigated as well. Si(46-x)P(x)Te(y) reveals a wide homogeneity range due to the presence of vacancies in the tellurium guest positions inside the smaller cage of the clathrate I structure. The vacancy ordering in the structure of Si(46-x)P(x)Te(y) causes the change of space group from Pm3n (ideal clathrate I) to Pm3 accompanied by the redistribution of P and Si atoms over different framework positions. Neutron powder diffraction confirmed that P atoms preferably form a cage around the vacancy-containing tellurium guest position. Additionally, (31)P NMR spin-spin relaxation experiments revealed the presence of sites with different coordination of phosphorus atoms. Precise determination of the composition of Si(46-x)P(x)Te(y) by WDXS showed slight but noticeable deviation (x < or = 2y) of phosphorus content from the Zintl counting scheme (x = 2y). The compound is diamagnetic while resistivity measurements show activated behavior or that of heavily doped semiconductors. Thermal analysis revealed high stability of the investigated clathrate: Si(46-x)P(x)Te(y) melts incongruently at approximately 1460 K in vacuum and is stable in air against oxidation up to 1295 K.
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Affiliation(s)
- J V Zaikina
- Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia
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Thiel F, Hein M, Schwarz U, Sachs J, Seifert F. Combining magnetic resonance imaging and ultrawideband radar: a new concept for multimodal biomedical imaging. Rev Sci Instrum 2009; 80:014302. [PMID: 19191450 DOI: 10.1063/1.3065095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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
Due to the recent advances in ultrawideband (UWB) radar technologies, there has been widespread interest in the medical applications of this technology. We propose the multimodal combination of magnetic resonance (MR) and UWB radar for improved functional diagnosis and imaging. A demonstrator was established to prove the feasibility of the simultaneous acquisition of physiological events by magnetic resonance imaging and UWB radar. Furthermore, first in vivo experiments have been carried out, utilizing this new approach. Correlating the reconstructed UWB signals with physiological signatures acquired by simultaneous MR measurements, representing respiratory and myocardial displacements, gave encouraging results which can be improved by optimization of the MR data acquisition technique or the use of UWB antenna arrays to localize the motion in a focused area.
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Affiliation(s)
- F Thiel
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany.
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Komalapriya C, Thiel M, Romano MC, Marwan N, Schwarz U, Kurths J. Reconstruction of a system's dynamics from short trajectories. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 78:066217. [PMID: 19256935 DOI: 10.1103/physreve.78.066217] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 09/02/2008] [Indexed: 05/27/2023]
Abstract
Long data sets are one of the prime requirements of time series analysis techniques to unravel the dynamics of an underlying system. However, acquiring long data sets is often not possible. In this paper, we address the question of whether it is still possible to understand the complete dynamics of a system if only short (but many) time series are observed. The key idea is to generate a single long time series from these short segments using the concept of recurrences in phase space. This long time series is constructed so as to exhibit a dynamics similar to that of a long time series obtained from the corresponding underlying system.
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Affiliation(s)
- C Komalapriya
- Center for Dynamics of Complex Systems, University of Potsdam, 14415 Potsdam, Germany.
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Geyer C, Helbig M, Schwarz U, Sachs J, Hein MA, Kaiser WA, Hilger I. Can ultra-wideband (UWB) radar be used for imaging purposes? Preliminary in vitro investigations. ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-0028-1085912] [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: 10/21/2022]
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Geyer C, Helbig M, Schwarz U, Sachs J, Hein MA, Kaiser WA, Hilger I. Ultrabreitband (UWB)-Radar-Technologie in der Bildgebenden Tumordiagnostik – erste Untersuchungen. ROFO-FORTSCHR RONTG 2008. [DOI: 10.1055/s-2008-1073932] [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: 10/21/2022]
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Figueroa C, Schwarz U, Kurths J, Postnova S, Braun H, Hemmeter U. Analysis of Sleep-EEG from Depressed Patients. Pharmacopsychiatry 2007. [DOI: 10.1055/s-2007-991836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Pedrazzini P, Wilhelm H, Jaccard D, Jarlborg T, Schmidt M, Hanfland M, Akselrud L, Yuan HQ, Schwarz U, Grin Y, Steglich F. Metallic state in cubic FeGe beyond its quantum phase transition. Phys Rev Lett 2007; 98:047204. [PMID: 17358807 DOI: 10.1103/physrevlett.98.047204] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Indexed: 05/14/2023]
Abstract
We report on results of electrical resistivity and structural investigations on the cubic modification of FeGe under high pressure. The long-wavelength helical order (T(C) = 280 K) is suppressed at a critical pressure p(c) approximately 19 GPa. An anomaly at T(X)(p) and strong deviations from a Fermi-liquid behavior in a wide pressure range above p(c) suggest that the suppression of T(C) disagrees with the standard notion of a quantum critical phase transition. The metallic ground state persisting at high pressure can be described by band-structure calculations if zero-point motion is included. The shortest FeGe interatomic distance display discontinuous changes in the pressure dependence close to the T(C)(p) phase line.
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Affiliation(s)
- P Pedrazzini
- DPMC, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland
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Werheit H, Paderno Y, Filippov V, Paderno V, Pietraszko A, Armbrüster M, Schwarz U. Peculiarities in the Raman spectra of ZrB12 and LuB12 single crystals. J SOLID STATE CHEM 2006. [DOI: 10.1016/j.jssc.2005.11.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Die neurologische Untersuchung ist eine Herausforderung an den Arzt wie an den Patienten. Das Ziel ist die Erfassung eines Syndroms – und nicht die Diagnose – mit den Werkzeugen der Anamnese und Befunderhebung. Diese werden in groben Zügen, gewichtet, plakativ und gelegentlich provokativ dargestellt.
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Affiliation(s)
- U Schwarz
- Neurologische Klinik, UniversitätsSpital Zürich.
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Demchyna R, Prots Y, Schnelle W, Burkhardt U, Schwarz U. Crystal structures of (barium, europium) platinum trigermanium, Ba1-xEuxPtGe3 (x = 0, 0.27, 1). Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.0002] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract BaGe3Pt, tetragonal, I4mm (no. 107), a = 4.5636(2) Å, c = 10.2341(6) Å, V = 213.1 Å3, Z = 2, Rgt(F) = 0.030, wRref(F2) = 0.074, T = 293 K. Ba0.73Eu0.27Ge3Pt, tetragonal, I4mm (no. 107), a = 4.5432(1) Å, c = 10.1763(2) Å, V = 210.0 Å3, Z = 2, Rgt(F) = 0.025, wRref(F2) = 0.061, T = 293 K. EuGe3Pt, tetragonal, I4mm (no. 107), a = 4.4633(1) Å, c = 10.0625(4) Å, V = 200.5 Å3, Z = 2, Rgt(F) = 0.018, wRref(F2) = 0.035, T = 293 K.
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Affiliation(s)
- R. Demchyna
- 1Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - Yu. Prots
- 1Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - W. Schnelle
- 1Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - U. Burkhardt
- 1Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
| | - U. Schwarz
- 1Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, 01187 Dresden, Germany
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Demchyna R, Prots Y, Schnelle W, Burkhardt U, Schwarz U. Crystal structures of (barium, europium) platinum trigermanium, Ba1-xEuxPtGe3 (x = 0,0.27,1). Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.221.14.109] [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: 11/24/2022]
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Marcar VL, Schwarz U, Martin E, Loenneker T. How depth of anesthesia influences the blood oxygenation level-dependent signal from the visual cortex of children. AJNR Am J Neuroradiol 2006; 27:799-805. [PMID: 16611767 PMCID: PMC8134003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND PURPOSE Functional MR imaging (fMRI) is playing an important role in investigations of cortical development and maturation. Functional MR imaging in young children or infants frequently involves measuring a clinical population under sedation or anesthesia. We examined the effect of depth of anesthesia on the extent and amplitude of the blood oxygen level-dependent (BOLD) response. METHOD We performed BOLD-based fMRI on a visual stimulus flickering at 8 Hz at sevoflurane concentrations of 0.5 minimum alveolar concentration (MAC), 0.75 MAC, and 1.0 MAC, on 16 children at least 5 years of age. We determined the extent of activation by counting the number of activated voxels and assessed the change in the local deoxyhemoglobin concentration by comparing DeltaR2*. RESULTS The number of activated voxels of the positive BOLD response was higher at 0.75 MAC than at 0.5 MAC or 1.0 MAC. The magnitude of their mean DeltaR2* steadily declined as the level of sevoflurane was increased from 0.5 MAC to 1.0 MAC. The extent of activation of the negative BOLD response declined progressively from 0.5 MAC to 1.0 MAC. The magnitude of their mean amplitude of the DeltaR2* did not change with sevoflurane concentrations. The change in the extent of activation and the magnitude of DeltaR2* when the concentration of sevoflurane increased from 0.5 MAC to 0.75 MAC was due to its vasodilative property. The change in the extent of activation and the amplitude of DeltaR2* following the increase in the concentration of sevoflurane from 0.75 MAC and 1.0 MAC was due to its anesthetic property. This was the case for both the positive and negative BOLD response. CONCLUSIONS Careful adjustment of anesthetic depth can be used advantageously when performing BOLD-based fMRI measurements in children.
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Affiliation(s)
- V L Marcar
- Department of Neuropsychology, University of Zurich, Zurich, Switzerland
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Danzer E, Schwarz U, Wehrli S, Radu A, Adzick NS, Flake AW. Retinoic acid induced myelomeningocele in fetal rats: characterization by histopathological analysis and magnetic resonance imaging. Exp Neurol 2005; 194:467-75. [PMID: 15893307 DOI: 10.1016/j.expneurol.2005.03.011] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [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: 11/22/2004] [Revised: 03/11/2005] [Accepted: 03/11/2005] [Indexed: 12/29/2022]
Abstract
The prevention of human neural tube defects by folic acid administration and the potential for fetal surgical intervention for myelomeningocele (MMC) have renewed interest in the molecular pathways and pathophysiology of spina bifida. Animal models for assessment of the early developmental biology and pathophysiology of this lesion are needed. The goal of this study was to develop and characterize a non-surgical rat model of MMC. Time-dated Sprague-Dawley rats were gavage fed different doses of retinoic acid (RA) dissolved in olive oil at E10 (maternal n = 55, fetal n = 505). Control animals received olive oil alone (maternal n = 20, fetal n = 265) or were untreated (maternal n = 5, fetal n = 63). Fetuses were analyzed by detailed histopathology and MRI. Overall, isolated MMC occurred in 60.7% (307/505) of RA-exposed fetuses and no controls. Histopathology confirmed the entire spectrum of severity observed in human MMC, ranging from exposure of the cord with intact neural elements to complete cord destruction. MRI of the brain of MMC fetuses confirmed structural changes similar to humans with Arnold-Chiari malformation, including downward displacement of the cerebellum to just above the foramen magnum and compression of the developing medulla into a small posterior fossa. In conclusion, the RA-induced rat model of MMC is developmentally and anatomically analogous to human MMC. This relatively efficient and cost-effective model of MMC should facilitate investigation of the developmental biology and pathophysiology of MMC, and may be useful for the evaluation of further strategies for prenatal treatment.
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Affiliation(s)
- E Danzer
- The Children's Hospital of Philadelphia, The Children's Institute for Surgical Science, The University of Pennsylvania School of Medicine, Abramson Research Center, Room 1116B, 3615 Civic Center Boulevard, Philadelphia, PA 19104-4318, USA
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Wosylus A, Burkhardt U, Schnelle W, Schwarz U. High pressure synthesis of EuGa 2-xSi 4+x[x = 1.3 (1)]. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305080773] [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: 11/10/2022] Open
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Abstract
HISTORY AND CLINICAL FINDINGS A 53-year-old West African man presented two years after a travel to Guinea because of severe headache, neck stiffnes, fever and pruritus. The patient had been in orthopedical treatment for the last five months. INVESTIGATIONS Stool microscopy revealed a high number of Strongyloides stercoralis larvae. Hematology, biochemistry and all other parasitology results were normal. HIV-1/2 testing was negative and CD4+-lymphocyte count was normal. Concomitant infection by Human T Cell lymphotropic virus type 1 (HTLV-1) was confirmed by serology and PCR. The phylogenetic analysis confirmed African origin of the virus. TREATMENT The infection responded to a five-day course of albendazol at 400 mg/d but during the following five years repeat recrudescences were observed inspite of high-dosage and prolonged antiparasitic treatments. Eventually, eradication of the infection was achieved by a four day course of ivermectin 0.2 mg/kg/d. CONCLUSIONS Although both strongyloidiasis and HTLV-1 infections occur most frequently in tropical areas, these may also be observed in temperate regions. Suppression of the immune system by HTLV-1 differs from that by HIV. CD4+-lymphocytes were rarely decreased. Prolonged treatment with ivermectin in a dosage exceeding the current recommendations may be required in HTLV-1 infected patients and was well tolerated. The unusual presentation of the infection with muscular symptoms contributed to the delay of the diagnosis. HTLV-1 positive patients must be monitored for years. They and their partners must be instructed how to prevent transmission of the virus.
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Affiliation(s)
- J Richter
- Tropenmedizinische Ambulanz, Klinik für Gastroenterologie, Hepatologie und Infektiologie, Heinrich-Heine-Universität, Düsseldorf.
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Abstract
The article sketches concepts of entertaining health education programmes on television as discussed in the new sub-discipline of health communication in Germany and describes some examples and aspects of cooperation between the Federal Center for Health Education (BZgA/FCHE) Cologne as an institutional health education agency and German television partners. Specific chances and problems of entertaining forms of mass media health education on television are discussed. Finally, perspectives for institutional health education in relation to television are discussed.
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Affiliation(s)
- U Schwarz
- Bundeszentrale für gesundheitliche Aufklärung, Köln.
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Neff KW, Schwarz U, Motsch L, Steinke W, Schwartz A, Düber C. Langzeit-Entwicklung von Dissektionen der A. carotis interna: Quantitative Blutvolumenfluss-Untersuchungen mit der 2D cine Phasen-Kontrast MR Technik. ROFO-FORTSCHR RONTG 2004; 176:992-1000. [PMID: 15237342 DOI: 10.1055/s-2004-813274] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To use the magnetic resonance (MR) phase-contrast technique as a non-invasive method to determine blood volume flow in internal carotid artery (ICA) dissection, which has variable initial volume flow reduction and long term hemodynamic compromise. ICA dissection can lead to partial or complete recanalization or persistent occlusion, and strong clinical motivation exists for reliable assessment of the blood flow, in particular blood volume flow, in the carotid artery circulation after ICA dissection. MATERIALS AND METHODS Blood volume flow in the carotid artery circulation was quantified in 28 patients with unilateral ICA dissection and 20 age-matched normal controls. Blood volume flow was measured in the ICAs and the common carotid arteries (CCAs) using 2D cine phase-contrast MR imaging. Final measurements were performed until after at least 6 months the hemodynamic compromise showed no changes by ultrasound and MRA. RESULTS In long term follow up, 11/28 patients demonstrated remaining vessel occlusion, 10/28 partial and 7/28 complete recanalizations. Patients with ICA occlusion showed a significant contralateral volume flow increase (mean 56 %, p < 0.001) in comparison to normal controls. Patients with partial recanalization demonstrated volume flow rates between 24 ml/min and 188 ml/min in the dissected ICA and a less but significant (p < 0.001) increase in the contralateral volume flow. In patients with complete recanalization, normal volume flow conditions were found for both ICAs and CCAs. CONCLUSION In ICA dissection, quantitative volume flow determination using 2D cine phase-contrast MR imaging is helpful in the initial assessment and long term follow-up of hemodynamic compromise. ICA dissection demonstrated a partial or complete recanalization in nearly (2/3) of the investigated patients and a persisting vessel occlusion in little more than (1/3). Compensatory contralateral increase in volume flow was found.
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Affiliation(s)
- K W Neff
- Institut für Klinische Radiologie, Universitätsklinikum Mannheim, Fakultät für Klinische Medizin Mannheim der Universität Heidelberg.
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Schmidt M, Ewald B, Prots Y, Cardoso-Gil R, Armbrüster M, Loa I, Zhang L, Huang YX, Schwarz U, Kniep R. Growth and Characterization of BPO4 Single Crystals. Z Anorg Allg Chem 2004. [DOI: 10.1002/zaac.200400002] [Citation(s) in RCA: 30] [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: 11/12/2022]
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Fedorchuk A, Prots Y, Schmidt M, Schnelle W, Burkhardt U, Schwarz U, Grin Y. Novel Derivatives of the CaIn2 Type of Structure: Yb1+xMg1—xGa4 (0≤x≤ 0.058) and YLiGa4. Z Anorg Allg Chem 2003. [DOI: 10.1002/zaac.200300308] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Akselrud LG, Hanfland M, Schwarz U. Refinement of the crystal structure of Sb-I, at 2.22 GPa. Z KRIST-NEW CRYST ST 2003. [DOI: 10.1524/ncrs.2003.218.jg.446] [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: 11/24/2022]
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Abstract
Abstract Bi, monoclinic, C12/m1 (No. 12), a = 6.67256(1) Å, b = 6.1108(2) Å, c = 3.30013(9) Å, β = 110.412(2)°, V = 126.1 Å3, Z = 4, R(P) = 0.118, R(I) = 0.087, T = 295 K, P = 2.54 GPa.
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Affiliation(s)
- L. G. Akselrud
- 1Lviv State University, Kyryla and Mefodija St. 6, 79005 Lviv, Ukraine
- 2Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, D-01187 Dresden, Germany
| | | | - U. Schwarz
- 2Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Str. 40, D-01187 Dresden, Germany
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Affiliation(s)
- G Geldner
- Klinik für Anästhesie und Intensivtherapie der Philipps Universität Marburg, Marburg.
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Schwarz U. Crystal structure of indium monosulfide, InS, at 7.9 GPa. Z KRIST-NEW CRYST ST 2002. [DOI: 10.1524/ncrs.2002.217.1.470] [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: 11/24/2022]
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Vötsch W, Nicholson G, Müller R, Stierhof YD, Gorb S, Schwarz U. Chemical composition of the attachment pad secretion of the locust Locusta migratoria. Insect Biochem Mol Biol 2002; 32:1605-1613. [PMID: 12429112 DOI: 10.1016/s0965-1748(02)00098-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This study is the first attempt to characterise the chemical composition of the secretion of the smooth pads of the locust Locusta migratoria and to relate this to the composition of the cuticle coverage of the pads and the wings. Gas-chromatography and mass-spectrometry (GC-MS) were the principal techniques used for the characterization of these materials. Secretion droplets were visualised and quantified with the aid of diverse microscopic techniques. The chemical composition of prints is shown to differ from the cuticle coverage, in particular, with respect to the fatty acid distribution: in the secretion, saturated and unsaturated fatty acids with chain lengths between C(16) and C(20) in both the free form and as glycerides predominate, whereas cuticle coverage contains waxes of long-chained fatty-acids bound to long-chain primary alcohols. The second important difference is the significant amount of glucose and other saccharides found in methanolyzates of the pad fluid. A considerable amount of the amino acids (up to 53%) was detected in the non-volatile portion of the fluid. Data obtained from the shock-freezing, carbon-platinum coating and replica preparation show that the secretory droplets contain nano-droplets on their surfaces. The results lead us to suggest that the pad secretion is an emulsion consisting of lipidic nano-droplets dispersed in an aqueous liquid. According to the chemical composition of the secretion, a high-viscosity of the fluid may be suggested. Presumably, the fluid is a kind of a coupling agent, promoting and strengthening adhesion between otherwise incompatible materials by providing the proximity of contact for intermolecular forces.
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Affiliation(s)
- W Vötsch
- Biochemistry Department, MPI of Developmental Biology, Spemannstr. 35, D-72076, Tübingen, Germany
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Affiliation(s)
- U Schwarz
- Neurologische Klinik, Universitätsspital, Zürich, Schweiz.
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