Double-walled carbon nanotubes (DWCNTs) were synthesized by catalytic chemical vapor deposition using Fe-Mo/MgO as a catalyst at 1000 degrees C under the mixture of methane and hydrogen gas. The nanotubes were purified by acid but were not damaged. Thermogravimetric analysis revealed the purity of the tubes to be about 90%. The high-resolution transmission electron microscopy image showed that DWCNTs have inner tube diameters of 1.4-2.6 nm and outer tube diameters of 2.3-3.4 nm. We observed radial breathing modes in Raman spectra, which are related to the diameter of inner nanotubes. The purified DWCNTs were mixed with organic vehicles and glass frit, and then they were screen-printed on glass substrate coated with indium tin oxide. The field emission properties of the screen-printed DWCNT films were examined by varying the amount of glass frit ingredient within the DWCNT paste. The results showed that DWCNT emitters had good emission properties such as turn-on field of 1.33-1.78 V/microm and high brightness. When the applied anode voltage was gradually increased, current density and brightness became saturated. We also observed DWCNTs adsorbed on the anode plate; they were DWCNTs peeled off from the cathode plate for field emission measurement.

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Atopic dermatitis (AD) is a chronic, relapsing, inflammatory skin disease. Children with AD tend to have a higher prevalence of food allergies. This study investigated the clinical significance of food sensitization in AD patients. A total of 266 AD patients participated in this study. The prevalence of food sensitization and clinically relevant sensitization were compared in the subjects according to their age and AD severity. Sera from all patients were analyzed for food-specific IgE levels using the Pharmacia CAP System FEIA. The serum specific IgE levels for egg, milk, peanut and soybean were measured. Patients were regarded as sensitized to the food if their food-specific IgE levels were above 0.35 kUA/L. Also the food-specific IgE levels, the so-called diagnostic decision point, which is recommended as the clinically relevant level, for clinical food allergy, as suggested by Sampson et al, was used as an alternative method. From the measurement of food-specific IgE antibodies of the four foods, egg was the most highly sensitized and the main causative allergenic food in children with AD. The positive rates of specific IgE to the four major food allergens, and the prevalences of clinically relevant food sensitization, were higher for all foods tested in the group less than 1 year of age, and were significantly higher in moderate to severe AD compared to mild AD in infants and young children. In summary, presence of food specific IgE is prevalent in infants and young children with AD, and clinically relevant food sensitization is important in Korean infants and children with moderate to severe AD.

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