Optically tunable and detectable magnetoelectric effects in the composite consisting of magnetic thin films and InGaN/GaN multiple quantum wells.

An optically tunable and detectable magnetoeletric (ME) effect has been discovered in the composite consisting of InGaN/GaN multiple quantum wells and magnetostrictive ferromagnetic Ni or FeCo thin films at room temperature. Due to the interactively optical and piezoelectric properties of nitride semiconductors, this composite provides an intriguing optically accessible system, in which the magnetoelectric effect can be both easily tuned and detected. The underlying mechanism can be well accounted for by the interplay among magnetostrictive, piezoelectric and optical transition. It thus offers a new paradigm to generate artificial material systems with magnetic/electric/optical inter-related/controllable properties.

Magnetic field modulation of photonic bandgap on FeCo/NiO half-shell array.

FeCo/NiO half-shell arrays were fabricated based on the periodic monolayer polystyrene spheres. The two-dimensional magnetic periodic arrays form well-defined photonic crystals with pronounced stop bands. Quite interestingly, it is found that the stop bands can be tuned by an external magnetic field. The underlying mechanism is attributed to the controllable dielectric constant of the magnetic FeCo film under an applied magnetic field. The results shown here may open up an avenue for magnetically tunable photonic crystal stop bands, which may be useful for the creation of new magneto-optical devices.

Magnetically tunable surface plasmon resonance based on a composite consisting of noble metal nanoparticles and a ferromagnetic thin film.

We demonstrate magnetically tunable surface plasmon resonance based on a composite consisting of noble metal nanoparticles and ferromagnetic thin film. We found that both the frequency and linewidth of the localized surface plasmon resonance can be manipulated by applying an external magnetic field. The underlying mechanism is attributed to the variation of the dielectric constant in the ferromagnetic thin film resulting from the change of magnetization. Our result shown here paves an alternative route for manipulation of the characteristics of the surface plasmon resonance, which may serve as a new design concept for the development of magneto-optical devices.

Frequency and phenotypic analysis of CD4+CD25+ regulatory T cells in children with juvenile idiopathic arthritis.

BACKGROUND AND PURPOSE: The aim of this study was to investigate the frequency of CD4(+)CD25(+) regulatory T cells and their phenotypic expression in peripheral blood of children with active and non-active juvenile idiopathic arthritis (JIA) and healthy controls, to determine if their frequency or phenotypic expression is involved in the immunoregulation of this disease. METHODS: From October 2004 to October 2005, 55 JIA patients and 55 age- and gender-matched healthy controls were enrolled in the study at National Taiwan University Hospital. Flow cytometry was used to determine the frequency of CD4(+)CD25(+) and CD4(+)CD25(hi) in CD4(+) T cells and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) expression on CD4(+)CD25(+) by tricolor staining. Basic profiles, medication history, clinical symptoms and laboratory data were obtained by chart review and outpatient department interviews. RESULTS: There was no significant difference in expression of CD4(+)CD25(+) T cells between patients with inactive JIA and normal controls (13.74+/-3.25% vs 12.85+/-3.68%, p>0.05). The expression of CD4(+)CD25(hi) T cells was significantly lower in inactive JIA patients than in normal controls (1.89+/-1.01% vs 2.76+/-1.28%, p<0.01). The expression of CTLA-4 on CD4(+)CD25(+) T cells was also significantly lower in inactive JIA patients compared with controls (4.37+/-2.02% vs 6.33+/-2.57%, p<0.001). CONCLUSION: We speculate that a decreased frequency of CD4(+)CD25(hi) regulatory T cells and lower level of CTLA-4 expression on CD4(+)CD25(+) regulatory T cells might play a role in the immunoregulation of JIA.

Reye's syndrome developing in an infant on treatment of Kawasaki syndrome.

Aspirin is commonly used as an anti-inflammatory therapy for Kawasaki syndrome. Early initiation with high dose aspirin (80 to > 100 mg/kg per day), followed by low-dose therapy at the afebrile stage, has been often used to reduce morbidity and mortality in coronary complications. We report a 10-month-old infant who was diagnosed with Kawasaki syndrome. Sudden onset of poor activity, poor appetite, lethargy, tachycardia, tachypnea, hepatomegaly, increased AST/ALT, coagulopathy and hyperammonemia developed 3 days after the high-dose aspirin therapy. His histopathological and ultrastructural findings from the liver biopsy were compatible with Reye's syndrome. He recovered completely, and there was no recurrence.