Molecular oxygen species formed on the surface of partially reduced TiO 2 (rutile) nanoparticles have been studied by in situ electron spin resonance (ESR) and diffuse-reflectance spectroscopies. ESR signals due to O 2 -(g z ) 2.020) and Ti 3+ appeared upon visible-light illumination at 77 K and vanished by raising the temperature in the dark. The numbers of O 2 and Ti 3+ radicals formed by sub-band-gap illumination were equal, suggesting a reversible electron transfer between peroxo O 2 2species and the adjacent Ti 4+ ion at an oxygen vacancy site on the TiO 2 surface:The ESR intensity was saturated by a prolonged illumination and a surface coverage of O 2 molecules adsorbed at the oxygen vacancy site was evaluated as 1.3 × 10 13 sites cm -2 . The spectral response for the generation rate of O 2 exhibited a broad peak at around 480 nm, in agreement with the absorption band observed by the diffuse-reflectance measurements. It was concluded that F-type color centers generated in subsurface layers of TiO 2 absorb the visible light to induce indirectly the electron-transfer reaction from O 2 2to Ti 4+ at the surface oxygen vacancy site.

Photoinduced electron transfer reactions of O 2 molecules adsorbed on the H 2 -reduced surface of TiO 2 (rutile) nanoparticles have been studied at 77 K by in situ ESR spectroscopy. Upon visible-light illumination, ESR signals due to O 2 -(g z ) 2.020) and Ti 3+ appeared and then returned to the original ones by raising the temperature in the dark. The numbers of O 2 -and Ti 3+ ions formed by illumination were equal, suggesting that a reversible electron transfer between peroxo O 2 2-species and the adjacent Ti 4+ ion occurs by sub-band gap illumination of TiO 2 .

The objective of this study was to determine whether paracetamol (acetaminophen) affects the outcome of children with fever due to bacterial infectious disease. A total of 208 outpatients aged 6 months to 15 years with pyrexia due to bacterial infection who had been examined at the Fujimoto Children's Hospital from March 1992 to May 1992. The number of antipyretic doses of paracetamol (10 mg/kg) a day received within 3 days of illness in the patients with acute fever (a38'C) was investigated. In this study, the patients were divided into two groups: (i) the pneumonia group, which consisted of 101 patients who were subsequently diagnosed as having pneumonia during their illness and (ii) the control group, which consisted of 107 patients who were subsequently diagnosed as having illness with fever that did not Progress to pneumonia. The mean number of daily doses was significantly higher for the pneumonia group (2.52 20.80) than for the control group (1.37 20.72, P < 0.001). There was no significant difference between the pneumonia group and the control group in body temperature during acute fever (38.7 f 0.65 vs 38.8 &0.54'C). The data suggest that frequent administration of antipyretics to children with infectious disease may lead to a worsening of their illness.

A simple and safe technique which is based on glow discharge is demonstrated for stable encapsulation of H atoms in cage-shaped silsesquioxanes at room temperature, leading to the encapsulation yield of ca. 10(-4) H atoms per molecule for 10-minute discharging, much faster than the conventional gamma-ray irradiation technique.