Elucidating the Quenching Mechanism of Tris(2,2'-bipyridyl)ruthenium(II) Complex in the Water-Glycerol Binary System Based on the Microscopic Structure of the Media.

Kinetic studies on the photochemical quenching reaction of the tris(2,2'-bipyridyl) ruthenium(II) complex ([Ru(bpy)3]2+) in water-glycerol binary media were conducted based on the Einstein-Smoluchowski (E-S) theory. Dynamic and static quenching behaviors were analyzed by comparing results from time-resolved spectroscopy and emission spectroscopy. While the dynamic quenching reaction aligns well with the E-S theory, static quenching was observed, leading to a notable increase in the overall photoquenching reaction rate constant. Employing chromatography and infrared spectroscopy, we correlated the microscopic molecular structure of the binary solvent system and the solvation environment around the emitters with the reaction mechanism. This correlation was found to correspond to ion pair formation and the confinement effect of the emitter, respectively.

Megahertz detection of spectroscopic polarization by a time-encoded supercontinuum vector beam.

We demonstrated a 40-MHz detection of spectroscopic polarization by a supercontinuum vector beam with a wavelength-dependent polarization state. To achieve the high-repetition-rate measurement, we detected the rotation angle of polarization and the spectrum by measuring the temporal waveform using a photodetector after expanding the pulse duration of the supercontinuum vector beam. The spectrum of the supercontinuum vector beam was measured using a spectrometer. We compared it with the temporal waveforms, confirming a good agreement of spectra between the conventional spectrometer and the temporal waveforms. The detection method is useful for many applications requiring high-repetition-rate spectroscopic-polarization measurements, such as the defect inspection of thin optical materials.

Effect of Childhood Disease on Hospital Presentation: A Survey of Pediatricians.

BACKGROUND: Determining when caregivers should take their children to a hospital is crucial in ensuring the health and safety of children. Because children cannot make these decisions on their own, caregivers bear the core responsibility for the wellness of their children. The aim of this study was to determine how disease, disability, and child behavior affect when and how often caregivers take their children to a hospital. METHODS: A structured anonymous online survey was circulated to pediatricians in Japan. Pediatricians were queried about the characteristics of their patients, including reactivity to pain, expression of pain, behavior at the hospital, and the timing of presentation. Patients were school-aged children and included those with autism spectrum disorder, attention-deficit hyperactivity disorder, Down syndrome, mental retardation, epilepsy, premature birth, and allergies. RESULTS: Sixty-eight of 80 pediatricians responded to the survey (85% response rate). The results indicated that caregivers of children with autism spectrum disorder, attention-deficit hyperactivity disorder, and mental retardation took them to the hospital later than was optimal. Conversely, children born prematurely and those with allergies were taken to hospitals even when symptoms were mild. CONCLUSIONS: Caregivers make decisions on when to present to hospital on the basis of their child's expression of pain and behavior. Guidelines should be developed to assist caregivers in determining when to present for treatment at a hospital.

The Roles of Dominance of the Nitric Oxide Fractions Nitrate and Nitrite in the Epilepsy-Prone EL Mouse Brain.

BACKGROUND: Oxidative stress is thought to be closely related to epileptogenesis. We have previously reported that nitric oxide (NO) levels are higher in epilepsy-prone EL mice between the ages of 3 and 8 weeks than in control mice. However, NO is divided into two fractions, nitrite (NO2) and nitrate (NO3), which appear to play different roles in epileptogenesis. METHODS: NO2 and NO3 levels were measured, in EL mice and the control mice, in the parietal cortex, which is thought to be the primary epileptogenetic center in EL mice, and measured in the hippocampus, which is thought to be the secondary center. RESULTS: NO3 levels in the hippocampus and parietal cortex of the immature EL mice (3 to 8 weeks of age) were significantly higher than those in the control mice; NO2 levels were significantly higher in the EL mice throughout the study period. The NO3 levels were significantly higher than the NO2 levels in the immature EL mice, but after the onset of ictogenesis at 10 weeks of age, the relative levels of the two fractions reversed. CONCLUSION: The reversal of the NO fraction distribution at the onset of seizures that we observed may be related to the developmental process of seizure susceptibility in the neural network of EL mice.