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Background: We evaluate long-term post-operative hippocampal volume (HV) on non-epileptic hippocampus using MR volumetry as well as the neuropsychological outcome in patients with surgery for unilateral mesial temporal lobe epilepsy (MTLE) and achieved seizure-freedom. Methods: We studied 1.5-Tesla MRI before and after epilepsy surgery in 24 patients with MTLE. Serial MRI studies were scheduled at 4 post-operative consecutive periods; 6m-1y; 1-2y; 2-3y; 3-5y. We compared neuropsychological outcomes for memory and estimated IQ at the same periods with serial MRI up to 3 years. Results: The pre-operative non-epileptic HV was significantly smaller than HV in age-matched controls (n=14) (p<0.05). The HV became progressively atrophic after the surgery (p<0.05), correlating with the age at surgery (p<0.05) and pre-operative larger non-epileptic HV (p<0.05), but not with seizure duration. In 14 patients with non-dominant MTLE, the smaller dominant HV at 2-3y period correlated with decline of verbal memory (p<0.05). Conclusions: Post-operative progression of non-epileptic hippocampal atrophy was found with significantly more pronounce in patients with older age at surgery and larger pre-operative non-epileptic hippocampus. After the epileptogenic hippocampus is resected, the remaining hippocampus alone might exhaust to maintain the memory, especially in elders.
We report three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging findings in a patient with relapsing polychondritis.
A 76-year-old woman initially presented with bilateral auricular swelling together with dyspnoea. Three months later, she experienced left hearing loss and recurrent vertigo. A biopsy of the auricle was performed and relapsing polychondritis was diagnosed. The patient underwent three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging 4 hours after intravenous injection of a standard dose of gadolinium. Gadolinium enhancement was visible throughout the vestibule and the endolymphatic space could not be visualised, suggesting breakdown of the blood–labyrinth barrier.
This is the first radiological report to demonstrate breakdown of the blood–labyrinth barrier in a case of relapsing polychondritis with inner ear impairment.
The wettability of Pb-free Sn-based solder over the Cu-based Cu60Zr30Ti10 bulk metallic glass surface was investigated. We observed that the as-polished surface was nonwetting for the solder, which was due to the surface oxide layer of ZrOx formed in air. After complete removal of the oxide layer, a thin layer of Ag was deposited on the clean Cu60Zr30Ti10 surface. The Ag-covered Cu60Zr30Ti10 surface showed relatively high resistivity to the reoxidation even in air, and thus the wettability of the Cu60Zr30Ti10 surface for the Sn-based solder was greatly improved.
We surveyed T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients. T1 (emm1) remained dominant through 1992 to 2000, but the dominant T3 (emm3.1) strains from 1992 to 1995 disappeared during 1996–2000. Strains of several emm genotypes emerged during 1996–2000, indicating alterations in the prevalent strains causing TSLS.
A new efficient injection method from a laser ion source to
a Radio Frequency Quadropole (RFQ) was proposed and is being
tested in RIKEN, Japan. A laser plasma is induced just before
the entrance of the RFQ and is injected directly into the RFQ
channel. Using an existing RFQ, first verification tests have
been completed successfully. Finally, the preliminary
specifications for the first RFQ dedicated to the new injection
scheme are presented.
The aligned carbon nanofibers were synthesized on Si substrates using RF magnetron sputtering with a hot filament. The hot filament was made of tungsten wire and its temperature was up to 2000°C during the deposition. Nitrogen was used as the sputter gas at a relatively low pressure of 2×10-2 Torr. The sputtering deposition was carried out at a substrate temperature of 700°C. The nanofibers were grown vertically on the substrates. The diameters and the density of the fibers were about 30–45 nm and 109 cm-2, respectively.
Real-time spectroscopic ellipsometry (RTSE) method was applied to study thermal cleaning process of silicon surfaces for epitaxial growth by ultra-high vacuum chemical vapor deposition (UHV-CVD). For the first time, in-situ observation of oxide decomposition process under Si2H6 ambience was carried out. The substrates with thin oxide formed by wet chemical treatment were heated up by infrared heater under UHV or under Si2H6 ambience in an UHV-CVD chamber and the oxide decomposition processes were observed by RTSE. Ellipsometric parameters Psi and Delta increase with the progress of oxide decomposition process and become constant with the completion of the decomposition. It was found that the oxide decomposition process consists of two phases and rate-determing processes are different in each phase. It was also found that Si2H6 lowers the activation energies of oxide decomposition process in each phase.
BaTiO3 and PZT films were prepared by single-step dip-coating from alkoxide-acetate solutions containing polyvinylpyrrolidone (PVP). Crack-free BaTiO3 and PZT films over 1 μm in thickness were obtained via single-step deposition. Stepwise heating of the gel films was found to improve densification of BaTiO3 films, reducing the thickness and increasing the optical transmittance, which was not, however, the case with PZT films, where the stepwise heating rather induced crack formation, leading to degraded transmittance. Residual stress was evaluated on spin-coating BaTiO3 films by measuring the substrate curvature, where a significant reduction in tensile stress was found to be caused by PVP.
Precipitation-hardened stainless steels are important structural materials in a variety of industrial applications in aircraft, chemical and power plants. These steels have a combination of good mechanical properties, corrosion resistance and simple fabrication process. Precipitation reaction in a PH 17-4 stainless steel which contains approximately 3 wt.% of Cu begins with formation of coherent copper-rich precipitate, which subsequently transform to incoherent fee Cu by further aging. By prolonged aging at 400 °C, embrittlement occurs as hardening progresses. Both the coarsening of Cu and the decomposition of the martensite matrix could be the reasons for this embrittlement. Thus, this study attempted to clarify the phase separation and the precipitation processes in a PH 17-4 stainless steel on prolonged aging by atom probe field ion microscopy (APFIM), in order to understand the mechanism of the degradation of mechanical properties by long term medium temperature aging.
To clarify the relationship between the epidemics of severe
invasive group A streptococcal
infections (streptococcal Toxic Shock-Like Syndrome; TSLS) and common group
streptococcal infections in Japan, we examined the T serotypes of
S. pyogenes strains (group A
streptococci) isolated from clinical specimens of the streptococcal
infections (17999 cases) in
the period 1990–5, including the severe infections (TSLS)
(29 cases) in the period 1992–5.
Characteristic points of the analyses were: (1) dominant serotypes
of the infections in these
periods were T12, T4, T1, T28 and TB3264, which were consistently isolated;
(2) isolates of T3
rapidly increased through 1990 to 1994 while T6 decreased in the
period 1990–3; (3) when
Japanese area was divided into three parts, T3 serotype tended to spread
out from the north-eastern to the south-western area; (4) strains of T3
and T1 serotypes were dominant in the
TSLS. Dominant-serotype strains of streptococcal infections did not
always induce severe
infections and dominance of T3 serotype in the TSLS seemed to be
correlated with the increase
of T3 in streptococcal infections. These results may indicate that
certain clones of S. pyogenes are involved in the
pathogenesis of the TSLS.
Unusual magnetic behaviours occur in thin Fe films grown on Ir(100) by Molecular Beam Epitaxy. Four different magnetic sites are actually observed in these layers by Conversion Electron Mössbauer Spectrometry. The magnetic relaxation phenomena found in the strained FCC structure together with spin wave softening observed in the strained BCC structure point to small magnetic correlations along the growth direction.
We present the results of calculations of the magnetic order in Fe/Cr systems with a mono-atomic step at the interface. The study of such a systems is of particular interest since it is believed that topological defects play an essential role in the exchange coupling mechanism in Fe/Cr multilayered systems. We show that assuming only collinear magnetism, an interfacial step creates a very extended magnetic defect in the Cr layer. On the other hand, when the local magnetic moments are allowed to rotate, the magnetic defect is very localized near the step and the presence of the step induces a non-collinear coupling between the Fe layers in Fe/Cr superlattices.
In this paper, the interrelation between structural and magnetic properties of ultra-thin Mn films epitaxially grown on (001) bcc Fe is studied. The Mn growth and in-plane structure were controlled by electron diffraction (RHEED). The structures of the Mn films were determined by using X-Ray absorption spectroscopy (SEXAFS). Finally, the magnetic properties were studied by using X-Ray magnetic circular dichroïsm (XMCD). All the experiments were performed under ultra-high vacuum. As shown by XMCD experiments, a magnetic transition is observed at 2 Mn monolayers. The analysis of RHEED and SEXAFS experimental results clearly demonstrates that a structural transition comes with this magnetic transition.
Different phases of FeN thin films and Fe/FeN multilayers were prepared by reactive rf sputtering. The release of nitrogen and the crystallographic transformations during annealing were monitored by thermal desorption spectrometry and X-ray diffraction experiments. Finally, the diffusivity of nitrogen in the γ-Fe4N phase was evaluated.
Magnetic X-Ray resonant scattering performed at the Dysprosium Lni absorption edge permits to study the magnetic behaviour of a 3000 Å thick Dy film. The development of an helical magnetic order gives rise to intense magnetic resonant harmonics. The energy dependence of the resonant intensity has been investigated and presents a double resonance at the second harmonic measured in the σ-π geometry. The accurate thermal variation of the turn angle and of the c-parameter is given. These evolutions reveal the stabilisation of the helical phase in the Dysprosium film compared to the bulk case.
Magnetic and magnetoresistive properties of magnetic thin films deposited on periodically structured substrates have been studied. By using a thermodynamical heat treatment, we activate the step bunching phenomenon on vicinal Si(111) substrates misoriented towards  which results in a laterally modulated surface with a period around 0.1 μm. Epitaxial magnetic thin films deposited on these substrates exhibit an in-plane uniaxial anisotropy and a specific magnetoresistive behavior which characterizes the magnetization reversal process. In this contribution, we demonstrate that these properties can also be observed in non-epitaxial structures grown either by molecular beam epitaxy or by sputtering. In particular, magnetotransport measurements show that by varying parameters such as the nature of the magnetic metal, the layer thickness or the strength of the induced anisotropy, we can modulate the interplay between the anisotropy and the exchange stiffness, and, consequently, observe gradual magnetization reversal behaviors between a Stoner-Wohlfarth uniform mode and a non-uniform mode.
The effect of in-plane strain on the magnetic anisotropy of -oriented epitaxial TbFe2 films was studied. DC magnetron cosputtering was used to grow epitaxial TbFe2(110) films on A12O3(1120) substrates with an epitaxial Nb(110) buffer layer. Torque magnetometry showed that the films had uniaxial anisotropy, and the torque curves were used to determine the magnetic anisotropy constants of the films by analyzing the rotational hysteresis loss. Film strain was measured using synchrotron radiation. The film strain and anisotropy measurements confirm that the uniaxial anisotropy results from tensile strain in the TbFe2(110) films. This agrees with theoretical calculations of magnetic anisotropy which show that tensile strains can induce a uniaxial anisotropy in TbFe2(110) films.
We investigated the induced magnetic behaviour of the Ag of Fe/Ag multilayers with low temperature nuclear orientation. The experiments show induced magnetic moments in all samples. Furthermore, multilayers with 2ML and 4ML of Ag, these moments do not lie in the plane of the multilayer at low external magnetic fields.