Measurement of positron lifetime to probe the mixed molecular states of liquid water

Positron lifetime spectra were measured in liquid water at temperatures between 0c and 50c. The long lifetime of ortho-positronium atoms (o-Ps) determined by electron pick-off in molecular substances decreases smoothly by 10% as the temperature is raised. This lifetime temperature dependence can be explained by combining the Ps-bubble model and the mixture state model of liquid water.Comment: 11 pages, 6 page

The Data Acquisition System for the KOTO Experiment

We developed and built a new system of readout and trigger electronics, based on the waveform digitization and pipeline readout, for the KOTO experiment at J-PARC, Japan. KOTO aims at observing the rare kaon decay $K_{L}\rightarrow\pi^{0}\nu\bar{\nu}$. A total of 4000 readout channels from various detector subsystems are digitized by 14-bit 125-MHz ADC modules equipped with a 10-pole Bessel filter in order to reduce the pile-up effects. The trigger decision is made every 8-ns using the digitized waveform information. To avoid dead time, the ADC and trigger modules have pipelines in their FPGA chips to store data while waiting for the trigger decision. The KOTO experiment performed the first physics run in May 2013. The data acquisition system worked stably during the run.Comment: 5 pages,12 figures, Transactions on Nuclear Science, Proceedings of the 19th Real Time Conference, Preprin

Biomonitoring of Urinary Cotinine Concentrations Associated with Plasma Levels of Nicotine Metabolites after Daily Cigarette Smoking in a Male Japanese Population

Human biomonitoring of plasma and urinary levels of nicotine, cotinine, and 3′-hydroxycotinine was conducted after daily cigarette smoking in a population of 92 male Japanese smokers with a mean age of 37 years who had smoked an average of 23 cigarettes per day for 16 years. Members of the population were genotyped for the nicotine-metabolizing enzyme cytochrome P450 2A6 (CYP2A6). The mean levels of nicotine, the levels of its metabolites cotinine and 3′-hydroxycotinine, and the sum of these three levels in subjects one hour after smoking the first cigarette on the sampling day were 20.1, 158, 27.7, and 198 ng/mL in plasma and 846, 1,020, 1,010, and 2,870 ng/mL in urine under daily smoking conditions. Plasma levels of 3′-hydroxycotinine and urinary levels of nicotine and 3′-hydroxycotinine were dependent on the CYP2A6 phenotype group, which was estimated from the CYP2A6 genotypes of the subjects, including those with whole gene deletion. Plasma cotinine levels were significantly correlated with the number of cigarettes smoked on the day before sampling (r = 0.71), the average number of cigarettes smoked daily (r = 0.58), and the Brinkman index (daily cigarettes × years, r = 0.48) under the present conditions. The sum of nicotine, cotinine, and 3′-hydroxycotinine concentrations in plasma showed a similar relationship to that of the plasma cotinine levels. Urinary concentrations of cotinine and the sum of nicotine metabolite concentrations also showed significant correlations with the plasma levels and the previous day’s and average cigarette consumption. The numbers of cigarettes smoked per day by two subjects with self-reported light smoking habits were predicted by measuring the urinary cotinine concentrations and using linear regression equations derived from above-mentioned data. These results indicate that biomonitoring of the urinary cotinine concentration is a good, easy-to-use marker for plasma levels of cotinine and the sum of nicotine metabolites in smokers independent of genetic polymorphism of CYP2A6

Human Blood Concentrations of Cotinine, a Biomonitoring Marker for Tobacco Smoke, Extrapolated from Nicotine Metabolism in Rats and Humans and Physiologically Based Pharmacokinetic Modeling

The present study defined a simplified physiologically based pharmacokinetic (PBPK) model for nicotine and its primary metabolite cotinine in humans, based on metabolic parameters determined in vitro using relevant liver microsomes, coefficients derived in silico, physiological parameters derived from the literature, and an established rat PBPK model. The model consists of an absorption compartment, a metabolizing compartment, and a central compartment for nicotine and three equivalent compartments for cotinine. Evaluation of a rat model was performed by making comparisons with predicted concentrations in blood and in vivo experimental pharmacokinetic values obtained from rats after oral treatment with nicotine (1.0 mg/kg, a no-observed-adverseeffect level) for 14 days. Elimination rates of nicotine in vitro were established from data from rat liver microsomes and from human pooled liver microsomes. Human biomonitoring data (17 ng nicotine and 150 ng cotinine per mL plasma 1 h after smoking) from pooled five male Japanese smokers (daily intake of 43 mg nicotine by smoking) revealed that these blood concentrations could be calculated using a human PBPK model. These results indicate that a simplified PBPK model for nicotine/cotinine is useful for a forward dosimetry approach in humans and for estimating blood concentrations of other related compounds resulting from exposure to low chemical doses

Seismic reflection survey using Vibroseis in Zama city and Hiratsuka city, Kanto basin, central Japan

Seismic reflection survey using Vibroseis with a line length of 13km was conducted around Zama city and Hiratsuka city, in the southwest part of the Kanto basin. Seismic refraction records were also acquired by shooting at the both ends of the survey line with over 100 vertical stacks. From the seismic section, a clear reflector interpreted as the top of the acoustic basement is identified. The basement has a very complex structure with depths varying from 200m to 1200 m. As a result of a refraction method analysis, the P-wave velocity of the basement is estimated to be about 4.3 km/s. Comparing acoustic logging data of Atsugi observation well, it corresponds to the lower part of the Aikawa Group (Miocene volcanics). The interpreted basement has a different velocity and geology from that commonly observed in the Kanto plain (4.8-5.5 km/s layer). Above the basement, sediments can be divided into two parts by a remarkable reflector seen at depths of 200 300m at both ends of the line. As this reflector has a velocity of 2.3-2.4 km/s, this corresponds to the boundary between the Sagami Group (Quaternary sediments) and the Aikawa Group observed at the Atsugi well. The Sagami Group contains sharp and continuous reflectors with flat or gentle dips, whereas the upper part of the Aikawa Group is accompanied with considerable folds and faults