Neonicotinoids are pesticides used worldwide. They bind to insect nicotinic acetylcholine receptors (nAChRs) with high affinity. We previously reported that clothianidin (CTD), one of the latest neonicotinoids, reduced antioxidant expression and induced germ cell death in the adult testis of vertebrates. Here, we investigated the male reproductive toxicity of prenatal and early postnatal exposure to CTD, because it is likely that developmental exposure more severely affects the testis compared to adults due to the absence of the blood-testis barrier. Pregnant C57BL/6 mice were given water gel blended with CTD (0, 10 or 50 mg/kg/day; no-observed-adverse-effect-level [NOAEL for mice]: 47.2 mg/kg/day) between gestational day 1 and 14 days post-partum. We then examined the testes of male offspring at postnatal day 14. The testis weights and the numbers of germ cells per seminiferous tubule were decreased in the CTD-50 group, and abnormal tubules containing no germ cells appeared. Nevertheless, the apoptotic cell number and proliferative activity were not significantly different between the control and CTD-exposed groups. There were no significant differences in the androgen-related parameters, such as the Leydig cell volume per testis, the Sertoli cell number and the tubule diameter. The present study is the first demonstration that in utero and lactational exposures to CTD at around the NOAEL for mice reduce the germ cell number, but our findings suggest that these exposures do not affect steroidogenesis in Leydig cells during prenatal or early postnatal life.
An apparatus for measurements of the heat capacity and the pressure coefficient of liquid He4 under pressure is reported. A tunnel diode oscillator is used to measure the change of the pressure. The frequency resolution and the reproducibility of the oscillator for pressure measurements are found to be 1×10-8 and 5×10-4, respectively. The temperature resolution of the system is 4×10-7K and the measurable range of pressure change is from 2×10-6bar to 30bar.
Gas sensors operated with a small battery is an exciting objective. The authors tried it with a thin film SnO{sub 2} semiconductor as a sensing element and IC-technics, and the other with a sintered SnO{sub 2} and various pulse driving methods. These tries have both advantages and disadvantages. Thin-film sensors suffer from low stability and low sensitivity to certain gases. SnO{sub 2} sensors have more favorable operating characteristics, but they require much power and have long response times. The authors corrected these shortcomings with good success through miniaturization of a SnO{sub 2} sensor.
Abstract A detector for continuous detennination of a trace amount of aqueous ozone, utilizing an ozone extraction process from liquid (water) into the gas phase and an In2O3 thin film semiconductor ozone gas sensor, has been developed. It offers many advantages including high sensitivity to aqueous ozone and high aqueous ozone selectivity in the presence of various kinds of interfering compounds in water. It is able to detect 0.5 ppb of aqueous ozone with a sufficient response. The response to 1 ppm of free chlorine in water was smaller than that to 10 ppb of aqueous ozone. Long term monitoring aqueous ozone over 100 days was performed in an experimental plant for ozone treatment in water supply with the present aqueous ozone detector. The readings of the detector agreed well with the results of iodometry during the monitoring.
A new method has been proposed for generating binary random sequence based on an M-sequence. The method is called random sampling method and the binary random sequence is generated by using successive k-tuples of an M-sequence and uniform random numbers.This paper describes the analysis for obtaining the optimal condition for the generating binary random sequence which has the most random property, by use of a new concept called merit factor Fr. The merit factor Fr is obtained from the expected values of the autocorrelation function of binary random sequence. The randomness of the binary random sequences generated by the random sampling method are evaluated by Fr. And it is shown that when the tuple length is equal to the period of the original M-sequence, the generated binary random sequence is considered to be the most random.
