126
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Gao CL, Wulfhekel W, Kirschner J. Revealing the 120 degrees antiferromagnetic Néel structure in real space: one monolayer Mn on Ag(111). PHYSICAL REVIEW LETTERS 2008; 101:267205. [PMID: 19437669 DOI: 10.1103/physrevlett.101.267205] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
With spin-polarized scanning tunneling microscopy operating in the constant current mode, the 120 degrees antiferromagnetic Néel structure was found for a monolayer Mn on Ag(111) in both fcc and hcp stacking. The existence of structurally equivalent, but magnetically distinguished, Mn islands was observed. While both the fcc and hcp Mn islands display the frustrated spin structure, the orientations of their magnetic moments differ by 30 degrees possibly due to the spin-orbit coupling.
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127
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Gao CL, Ernst A, Fischer G, Hergert W, Bruno P, Wulfhekel W, Kirschner J. Spin wave dispersion on the nanometer scale. PHYSICAL REVIEW LETTERS 2008; 101:167201. [PMID: 18999706 DOI: 10.1103/physrevlett.101.167201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Indexed: 05/27/2023]
Abstract
Hot electrons injected into antiferromagnetic Mn layers from the tip of a low temperature scanning tunneling microscope have been used to determine the energies, lifetimes, and momenta of antiferromagnetic spin waves on the nanometer scale. The spin waves show a linear dispersion with a velocity of 160+/-10 meV A and lifetimes that scale linearly with energy in agreement with neutron scattering and theory. It is shown that the method is sensitive enough to detect the influence of surface anisotropies on the spin wave dispersion.
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128
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Schessl J, Walter MC, Schreiber G, Schara U, Müller CR, Lochmüller H, Bönnemann CG, Korinthenberg R, Kirschner J. Phenotypic variability in siblings with calpainopathy (LGMD2A). ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2008; 27:54-58. [PMID: 19364062 PMCID: PMC2858935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Calpainopathy is an autosomal-recessive limb girdle muscular dystrophy (LGMD2A) characterized by selective atrophy and weakness of proximal limb girdle muscles. The clinical phenotype of the disease is highly variable inter-familial, but little is known about intra-familial variability. This study reports the phenotypic variability in eight sibling pairs with genetically proven LGMD2A. Although siblings with identical mutations were often similarly affected, in some families the age of onset and the clinical course varied considerably.
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129
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Haug V, Horvath R, Horvath R, Kühr J, Korinthenberg R, Kirschner J. G.P.3.09 Mutation in PDHA1 gene mimicking a Guillain-Barré-Syndrome. Neuromuscul Disord 2008. [DOI: 10.1016/j.nmd.2008.06.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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130
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Kley R, Kirschner J, Eger K, Fischer D, Huebner A, Vorgerd M. G.O.1 The phenotype of myofibrillar myopathy associated with p.W2710X mutation in filamin C: A study of 31 German patients. Neuromuscul Disord 2008. [DOI: 10.1016/j.nmd.2008.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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131
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Kley R, Kirschner J, Eger K, Fischer D, Huebner A, Vorgerd M. Charakterisierung des klinischen und morphologischen Phänotyps der Filaminopathie. AKTUELLE NEUROLOGIE 2008. [DOI: 10.1055/s-0028-1086652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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132
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Winkelmann A, Hartung D, Engelhard H, Chiang CT, Kirschner J. High efficiency electron spin polarization analyzer based on exchange scattering at FeW(001). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:083303. [PMID: 19044342 DOI: 10.1063/1.2949877] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on a compact electron spin analyzer based on exchange scattering from a magnetic surface. The heart of the detector is an Fe(001) thin film grown on W(001) with chemisorbed oxygen in the p(1 x 1) structure. The device is mounted at the exit of an energy dispersive analyzer and works at a scattering energy of about 13.5 eV. Its figure of merit is 2 x 10(-3), combined with an excellent stability of more than 2 weeks in UHV.
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133
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Kirschner J, Kerhervé G, Winkler C. Reflection-time-of-flight spectrometer for two-electron (e,2e) coincidence spectroscopy on surfaces. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:073302. [PMID: 18681695 DOI: 10.1063/1.2949869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In this article, a novel time-of-flight spectrometer for two-electron-emission (e,2egamma,2e) correlation spectroscopy from surfaces at low electron energies is presented. The spectrometer consists of electron optics that collect emitted electrons over a solid angle of approximately 1 sr and focus them onto a multichannel plate using a reflection technique. The flight time of an electron with kinetic energy of Ekin approximately 25 eV is around 100 ns. The corresponding time- and energy resolution are typically approximately 1 ns and approximately 0.65 eV, respectively. The first (e,2e) data obtained with the present setup from a LiF film are presented.
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134
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Gao CL, Ernst A, Winkelmann A, Henk J, Wulfhekel W, Bruno P, Kirschner J. Noncollinear surface spin density by surface reconstruction in the alloy NiMn. PHYSICAL REVIEW LETTERS 2008; 100:237203. [PMID: 18643540 DOI: 10.1103/physrevlett.100.237203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Indexed: 05/26/2023]
Abstract
At the (001) surface of the alloy Ni(50)Mn(50), a noncollinear spin density is observed in real space by spin-polarized scanning tunneling microscopy. The spin density of individual atoms also varies in both size and direction as a function of bias voltage, indicating a noncollinearity in the energy domain. The noncollinearity is driven by a surface reconstruction which breaks the otherwise high surface symmetry. First-principles electronic-structure calculations support the experimental observations and evidence the interplay of reconstruction and spin-orbit coupling.
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135
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Krömker B, Escher M, Funnemann D, Hartung D, Engelhard H, Kirschner J. Development of a momentum microscope for time resolved band structure imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:053702. [PMID: 18513070 DOI: 10.1063/1.2918133] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate the use of a novel design of a photoelectron microscope in combination to an imaging energy filter for momentum resolved photoelectron detection. Together with a time resolved imaging detector, it is possible to combine spatial, momentum, energy, and time resolution of photoelectrons within the same instrument. The time resolution of this type of energy analyzer can be reduced to below 100 ps. The complete ARUPS pattern of a Cu(111) sample excited with He I, is imaged in parallel and energy resolved up to the photoelectron emission horizon. Excited with a mercury light source (h nu=4.9 eV), the Shockley surface state at the energy threshold is clearly imaged in k-space. Electron-electron interactions are observed in momentum space as a correlation hole in two-electron photoemission. With the high transmission and the time resolution of this instrument, possible new measurements are discussed: Time and polarization resolved ARUPS measurements, probing change of bandstructure due to chemical reaction, growth of films, or phase transitions, e.g., melting or martensitic transformations.
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136
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Meyerheim HL, Sander D, Negulyaev NN, Stepanyuk VS, Popescu R, Popa I, Kirschner J. Buried Ni/Cu(001) interface at the atomic scale. PHYSICAL REVIEW LETTERS 2008; 100:146101. [PMID: 18518052 DOI: 10.1103/physrevlett.100.146101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Indexed: 05/26/2023]
Abstract
We present a quantitative surface x-ray analysis of the buried Ni/Cu(001) interface structure after deposition of 3 and 5 monolayers of Ni at room temperature. Interface mixing is found where 27+/-10% of top layer Cu atoms are exchanged by Ni. Atomic scale simulations reveal a kinetic pathway for the Ni/Cu-exchange process and explain the observed limited degree of intermixing. A disperse distribution of Ni within the Cu surface with a preferential Ni-Ni separation of 3-4 nearest neighbor distances is determined.
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137
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Mironets O, Meyerheim HL, Tusche C, Stepanyuk VS, Soyka E, Zschack P, Hong H, Jeutter N, Felici R, Kirschner J. Direct evidence for mesoscopic relaxations in cobalt nanoislands on Cu(001). PHYSICAL REVIEW LETTERS 2008; 100:096103. [PMID: 18352728 DOI: 10.1103/physrevlett.100.096103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Indexed: 05/26/2023]
Abstract
Surface x-ray diffraction in combination with scanning tunneling microscopy and molecular dynamics calculations provide first quantitative evidence for unusually large relaxations in nanometer-sized Co islands deposited on Cu(001) at 170 K. These lead to sharply reduced interatomic Co distances as low as 2.36 A as compared to bulk Co (2.51 A) involving low symmetry Co adsorption sites. Our results prove the validity of the concept of mesoscopic mismatch which governs the strain relaxation of nanosized islands in general.
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138
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Yildiz F, Luo F, Tieg C, Abrudan RM, Fu XL, Winkelmann A, Przybylski M, Kirschner J. Strongly enhanced orbital moment by reduced lattice symmetry and varying composition of Fe1-xCox alloy films. PHYSICAL REVIEW LETTERS 2008; 100:037205. [PMID: 18233034 DOI: 10.1103/physrevlett.100.037205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Indexed: 05/25/2023]
Abstract
We studied tetragonally distorted Fe(1-x)Co(x) alloy films on Rh(001), which show a strong perpendicular anisotropy in a wide thickness and composition range. Analyzing x-ray magnetic circular dichroism spectra at the L_(3,2) edges we found a dependence of the Co magnetic orbital moment on the chemical composition of the Fe(1-x)Co(x) alloy films, with a maximum at x=0.6. For this composition, we observed an out-of-plane easy axis of magnetization at room temperature for film thickness up to 15 monolayers. Since both the magnetic orbital moment and the anisotropy energy show similar composition dependence, it confirms that both quantities are directly related. Our experiments show that the adjustment of the Fermi level by a proper choice of the alloy composition is decisive for the large magnetic orbital moment and for a large magnetic anisotropy in a tetragonally distorted lattice.
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139
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Lebrecht D, Deveaud C, Beauvoit B, Bonnet J, Kirschner J, Mueller K, Venhoff N, Walker UA. Uridine supplementation with Mitocnol antagonizes antiretroviral nucleoside analogue-induced mitochondrial peripheral and cerebral neuropathy in vivo. J Int AIDS Soc 2008. [DOI: 10.1186/1758-2652-11-s1-p148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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140
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Kottlors M, Kirschner J. G.P.12.07 Reduced differentiation potential in Duchenne muscular dystrophy with increasing dystrophy. Neuromuscul Disord 2007. [DOI: 10.1016/j.nmd.2007.06.270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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141
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Meyerheim HL, Sander D, Popescu R, Pan W, Popa I, Kirschner J. Surfactant-mediated growth revisited. PHYSICAL REVIEW LETTERS 2007; 99:116101. [PMID: 17930451 DOI: 10.1103/physrevlett.99.116101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Indexed: 05/25/2023]
Abstract
The x-ray structure analysis of the oxygen-surfactant-mediated growth of Ni on Cu(001) identifies up to 0.15 monolayers of oxygen in subsurface octahedral sites. This questions the validity of the general view that surfactant oxygen floats on top of the growing Ni film. Rather, the surfactant action is ascribed to an oxygen-enriched zone extending over the two topmost layers. Surface stress measurements support this finding. Our results have important implications for the microscopic understanding of surfactant-mediated growth and the change of the magnetic anisotropy of the Ni films.
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142
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Tang WX, Zhang Y, Tudosa I, Prokop J, Etzkorn M, Kirschner J. Large wave vector spin waves and dispersion in two monolayer fe on w(110). PHYSICAL REVIEW LETTERS 2007; 99:087202. [PMID: 17930976 DOI: 10.1103/physrevlett.99.087202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Indexed: 05/25/2023]
Abstract
We present the first surface spin-wave (SW) dispersion measurements up to the surface Brillouin zone boundary of a two monolayer Fe film on W(110) by using spin-polarized electron energy loss spectroscopy. Pronounced features of SW peaks are observed in the spectra at room temperature. We found that the SW energies in the Fe film are strongly reduced compared to spin waves in bulk Fe and to theoretical predictions. Our results suggest that this reduction is caused by the reduction of exchange interaction within the 2 ML Fe on W(110) as compared to bulk Fe.
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143
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Tusche C, Meyerheim HL, Kirschner J. Observation of depolarized ZnO(0001) monolayers: formation of unreconstructed planar sheets. PHYSICAL REVIEW LETTERS 2007; 99:026102. [PMID: 17678236 DOI: 10.1103/physrevlett.99.026102] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Indexed: 05/16/2023]
Abstract
A novel nonpolar structure of 2 monolayer (ML) thick ZnO(0001) films grown on Ag(111) has been revealed, using surface x-ray diffraction and scanning tunneling microscopy. Zn and O atoms are arranged in planar sheets like in the hexagonal boron-nitride prototype structure. The observed depolarization is accompanied by a significant lateral 1.6% expansion of the lattice parameter and a 3% reduced Zn-O bond length within the sheets. The nonpolar structure stabilizes an atomically flat surface morphology unseen for ZnO surfaces thus far. The transition to the bulk wurtzite structure occurs in the 3-4 ML coverage range, connected to considerable roughening.
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144
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Schumann FO, Winkler C, Kirschner J. Correlation effects in two electron photoemission. PHYSICAL REVIEW LETTERS 2007; 98:257604. [PMID: 17678057 DOI: 10.1103/physrevlett.98.257604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Indexed: 05/16/2023]
Abstract
Many-body effects in solids are ultimately related to the correlation among electrons, which can be probed by double photoelectron emission. We have investigated the electron pair emission from a Cu(111) surface upon photon absorption. We are able to observe for the first time the full extension and shape of a depletion zone around the fixed emission direction of one electron. It has an angular extension of approximately 1.2 rad, which is independent of the electron energy.
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145
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Winkelmann A, Bisio F, Ocaña R, Lin WC, Nývlt M, Petek H, Kirschner J. Ultrafast optical spin injection into image-potential states of Cu(001). PHYSICAL REVIEW LETTERS 2007; 98:226601. [PMID: 17677868 DOI: 10.1103/physrevlett.98.226601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Indexed: 05/16/2023]
Abstract
We report the observation of a net spin polarization in the n=1 image-potential state at the Cu(001) surface. The spin polarization is achieved by spin-selective multiphoton excitation of electrons from the spin-orbit split Cu d bands to the image-potential state using circularly polarized ultrafast light pulses. We show that by tuning the exciting photon energy, we can adjust the resonant coupling of the image-potential state to d bands of different double-group symmetry. This allows us to tune the spin polarization injected into the image-potential state.
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146
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Kley RA, Hellenbroich Y, van der Ven PFM, Furst DO, Huebner A, Bruchertseifer V, Peters SA, Heyer CM, Kirschner J, Schroder R, Fischer D, Muller K, Tolksdorf K, Eger K, Germing A, Brodherr T, Reum C, Walter MC, Lochmuller H, Ketelsen UP, Vorgerd M. Clinical and morphological phenotype of the filamin myopathy: a study of 31 German patients. Brain 2007; 130:3250-64. [DOI: 10.1093/brain/awm271] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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147
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Gao CL, Schlickum U, Wulfhekel W, Kirschner J. Mapping the surface spin structure of large unit cells: reconstructed mn films on Fe(001). PHYSICAL REVIEW LETTERS 2007; 98:107203. [PMID: 17358562 DOI: 10.1103/physrevlett.98.107203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Indexed: 05/14/2023]
Abstract
Using spin-polarized scanning tunneling microscopy with ring electrodes, the in-plane spin polarization of Mn on Fe(001) was measured. A large (square root 10 x 2 square root 10)R18.4 degrees reconstruction with a noncollinear spin structure was found. By combining maps of the spin polarization for two orthogonal in-plane directions, the vector field of the polarization in the unit cell could be constructed. The complex behavior is explained on the basis of the tendency of Mn to form antiferromagnetically coupled surface dimers.
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148
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Korinthenberg R, Schessl J, Kirschner J. Clinical presentation and course of childhood Guillain-Barré syndrome: a prospective multicentre study. Neuropediatrics 2007; 38:10-7. [PMID: 17607598 DOI: 10.1055/s-2007-981686] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Presenting symptoms, clinical course and paraclinical findings in childhood Guillain-Barré syndrome (GBS) have rarely been investigated prospectively. We performed a multicentre study in GBS diagnosed according to international criteria. Clinical findings were recorded using an ordinal GBS score and additional scores for arm, cranial nerve and vegetative function, and pain. Electrophysiological and CSF investigations followed individual procedures in the local hospitals. Ninety-five children with a median age of 6.2 years were registered over 40 months (53 boys, 42 girls). 70 had suffered an infection and 8 had been vaccinated during the previous 6 weeks. The first symptom was usually a disturbance of gait or neuropathic pain. The symptoms progressed for a median of 7 days. At the height of the disease, 60% of patients were unable to walk and 24% could not use their arms. 46% showed cranial nerve involvement, and 51% autonomous dysfunction. 13% required artificial ventilation. 79% complained of neuropathic pain, half of them to a severe degree. Electrophysiological examination showed demyelination in 74%, and 26% of these presented with very low amplitude compound action potentials. Purely axonal changes were found in 11%. All but eight were treated with I.V. immunoglobulin. Improvement began on day 13 after the first symptom (median). Ability to walk unaided returned after 27 days. In the children observed over the long-term, it took 118 days for them to be free of symptoms. Transient deterioration after immunoglobulin treatment occurred in seven patients, two suffered relapsing GBS, and three developed CIDP. At the end of the observation period (288 days), 75% of patients were free of symptoms. 21% suffered residual symptoms having no effect on daily functioning. The more severely disabled 4% either suffered from CIDP or concurrent myelitis. With this prospective study, the results of earlier retrospective investigations are confirmed. Besides pareses and respiratory compromise, severe neuropathic pain frequently is a therapeutic challenge during the acute phase of the disease. The long-term prognosis is good for most children. However, a change to CIDP and concurrent myelitis can give rise to a worse prognosis.
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149
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Schessl J, Koga M, Funakoshi K, Kirschner J, Muellges W, Weishaupt A, Gold R, Korinthenberg R. Prospective study on anti-ganglioside antibodies in childhood Guillain-Barré syndrome. Arch Dis Child 2007; 92:48-52. [PMID: 16920757 PMCID: PMC2083162 DOI: 10.1136/adc.2006.098061] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Antiganglioside antibodies have been reported to play a part in the pathophysiology of Guillain-Barré syndrome (GBS). AIMS To investigate the prevalence and correlation of anti-ganglioside antibodies with clinical data in children with GBS in a multicentre clinical trial. METHODS Immunoglobin (Ig)G and IgM to GM1, GM1b, GD1a, GalNAc-GD1a, GD1b, GT1a, and GQ1b were measured by ELISA in sera obtained before treatment. In addition, serological testing for Campylobacter jejuni was carried out. In parallel, a group of adults with GBS and a control group of children without GBS or other inflammatory diseases were evaluated. RESULTS Sera from 63 children with GBS, 36 adults with GBS and 41 children without GBS were evaluated. Four of the children with GBS showed positive IgG to GM1, in one case combined with anti-GalNAc-GD1a and in one with anti-GD1b. Two others showed isolated positive IgG to GD1b and GT1a. One showed increased anti-GalNAc-GD1a IgM. In 5 of the 63 children, serological evidence of a recent infection with C jejuni was found, and this correlated significantly with the raised antibodies (p = 0.001). In the control group without GBS, no child showed positive IgG, but one showed anti-GalNAc-GD1a IgM. Compared with the adults with GBS, the frequency of antibodies in children was insignificantly lower. In our study, patients with positive antibodies did not show a more severe GBS course or worse outcome than those who were seronegative, and we could not show an increased incidence of axonal dysfunction. CONCLUSIONS In some children with GBS, one can detect raised IgG against various gangliosides, similar to that in adults. A recent infection with C jejuni is markedly associated with the presence of these antibodies. However, in contrast with what has been reported in adults, in this study we were unable to show a negative effect of these findings on the clinical course.
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150
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Balashov T, Takács AF, Wulfhekel W, Kirschner J. Magnon excitation with spin-polarized scanning tunneling microscopy. PHYSICAL REVIEW LETTERS 2006; 97:187201. [PMID: 17155571 DOI: 10.1103/physrevlett.97.187201] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Indexed: 05/12/2023]
Abstract
Using spin-polarized scanning tunneling microscopy, the local excitation of magnons in Fe and Co has been studied. A large cross section for magnon excitation was found for bulk Fe samples while for thin Co films on Cu(111) the cross section linearly scales with film thickness. Recording inelastic tunneling spectra with Fe coated W tips in a magnetic field, the magnonic nature of the excitation was proven. Magnon excitation could be detected without the use of a separating insulating layer opening up the possibility to directly study magnons in magnetic nanostructures via spin-polarized currents.
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