Measurement of the whole-body 137Cs in residents around the Chernobyl nuclear power plant

To understand the current situation of internal radiation exposure in the population around the Chernobyl Nuclear Power Plant (CNPP), we examined the 137Cs body burden in six residents of Belarus, Ukraine and Russia in 2002 and 2004 using the whole-body counter (WBC) at Nagasaki University (Japan). The data were compared with those of our previous study performed in 1993-1994 using the same method. In 2002 and 2004, peaks of 137Cs were detected in two residents from Gomel, which was heavily contaminated by the CNPP accident, one from Minsk (Belarus) and one from Kiev (Ukraine), but another resident from Minsk showed no 137Cs peaks. The results of the present study suggests that residents around the CNPP are still exposed to chronic 137Cs internal irradiation, probably due to the daily consumption of contaminated domestic foods, but the risk of any disease by the irradiation is quite low. Long-term follow-up of WBC around the CNPP is useful and may contribute to radiation safety regulation together with a reduction of unnecessary radiophobia for the residents.     

Formation of Aluminosilicate Glasses Containing Rare-Earth Oxides

Formation of aluminosilicate glasses containing oxides of rare-earth elements, e.g. Sc, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, and Yb, was studied by melting at 1550°C and air quenching. The upper limit of the amount of rare-earth oxide which can be incorporated into the aluminosilicate glasses decreases according to the lanthanide contraction.     

Effects of sulfated fucan,ascophyllan, from the brown Alga Ascophyllum nodosum on various cell lines: A comparative study on ascophyllan and fucoidan

The effects of fucose-containing sulfated polysaccharides, ascophyllan and fucoidan, isolated from the brown alga Ascophyllum nodosum, on the growth of various cell lines (MDCK, Vero, PtK₁, CHO, HeLa, and XC) were investigated. In a colony formation assay, ascophyllan and fucoidan showed potent cytotoxic effects on Vero and XC cells, while other cell lines were relatively resistant to these polysaccharides. Almost no significant effects of these polysaccharides were observed in the cell lines tested using the Alamar blue cytotoxicity assay over 48 h with varying initial cell densities (2500–20,000 cells/well) in growth medium. Interestingly, a significant growth promoting effect of ascophyllan on MDCK cells was observed, whereas treatment with fucoidan showed growth suppressive effects on this cell line under the same experimental conditions. These results suggest that ascophyllan is distinguishable from fucoidan in terms of their bioactivities. This is the first report of the growth promoting effects of a sulfated fucan on a mammalian cell line under normal growth conditions.     

Detection of norovirus RNA in bivalve molluscs by using bacteria-culture-employed method (A3T method)

Norovirus (NV) RNA has rarely been detected in foods despite the use of highly sensitive methods such as RT-PCR and real-time RT-PCR. In the modified method (A3T method) reported previously, a bacterial culture process was introduced into the standard protocol for NV detection to remove some inhibitor(s) present in food ingredients. To confirm the efficiency of the A3T method and to examine NV contamination in bivalve molluscs, we tried to detect NV RNA in bivalve molluscs on the market and in oyster samples associated with foodborne outbreaks by using the standard method and the A3T method. NV RNAs were detected in 20 samples (18.0%) of 111 bivalve molluscs, including oysters, on the market by use of the A3T method, while only one sample (0.9%) was positive according to the standard method. NV RNA was also detected in 10 of 35 oyster samples related to foodborne outbreaks by the A3T method. Those results show that the A3T method is suitable for the detection of NV in bivalve molluscs in general laboratories.     

Genotoxicity of nano/microparticles in in vitro micronuclei, in vivo comet and mutation assay systems

Background

Recently, manufactured nano/microparticles such as fullerenes (C₆₀), carbon black (CB) and ceramic fiber are being widely used because of their desirable properties in industrial, medical and cosmetic fields. However, there are few data on these particles in mammalian mutagenesis and carcinogenesis. To examine genotoxic effects by C₆₀, CB and kaolin, an in vitro micronuclei (MN) test was conducted with human lung cancer cell line, A549 cells. In addition, DNA damage and mutations were analyzed by in vivo assay systems using male C57BL/6J or gpt delta transgenic mice which were intratracheally instilled with single or multiple doses of 0.2 mg per animal of particles.

Results

In in vitro genotoxic analysis, increased MN frequencies were observed in A549 cells treated with C₆₀, CB and kaolin in a dose-dependent manner. These three nano/microparticles also induced DNA damage in the lungs of C57BL/6J mice measured by comet assay. Moreover, single or multiple instillations of C₆₀ and kaolin, increased either or both of gpt and Spi^- mutant frequencies in the lungs of gpt delta transgenic mice. Mutation spectra analysis showed transversions were predominant, and more than 60% of the base substitutions occurred at G:C base pairs in the gpt genes. The G:C to C:G transversion was commonly increased by these particle instillations.

Conclusion

Manufactured nano/microparticles, CB, C₆₀ and kaolin, were shown to be genotoxic in in vitro and in vivo assay systems.     

Low Capture Switching Activity Test Generation for Reducing IR-Drop in At-Speed Scan Testing

At-speed scan testing, based on ATPG and ATE, is indispensable to guarantee timing-related test quality in the DSM era. However, at-speed scan testing may incur yield loss due to excessive IR-drop caused by high test (shift & capture) switching activity. This paper discusses the mechanism of circuit malfunction due to IR-drop, and summarizes general approaches to reducing switching activity, by which highlights the problem of current solutions, i.e. only reducing switching activity for one capture while the widely used at-speed scan testing based on the launch-off-capture scheme uses two captures. This paper then proposes a novel X-filling method, called double-capture (DC) X-filling, for generating test vectors with low and balanced capture switching activity for two captures. Applicable to dynamic & static compaction in any ATPG system, DC X-filling can reduce IR-drop, and thus yield loss, without any circuit/clock modification, timing/circuit overhead, fault coverage loss, and additional design effort.

Using Turmeric Oil as a Solvent Improves the Distribution of Sesamin-Sesamolin in the Serum and Brain of Mice

Accumulation of amyloid-β peptide is associated with Alzheimer's dementia. Previously, we reported that sesamin and sesamolin inhibited β-secretase activity in vitro, and each was transported to the serum and brain in mice after oral administration. However, the bioavailability of sesamin and sesamolin was poor in mice. In this study, we aimed to improve the bioavailability of sesamin and sesamolin. We found that the levels of sesamin and sesamolin in mouse serum and brain were higher after the administration of a mixture of sesame extract and turmeric oil (MST) than those after administering sesame extract alone. Serum sesamin and sesamolin contents in the MST-treated group were 23-fold and 15-fold higher, respectively, than those in the sesame extract-treated group. Brain sesamin and sesamolin contents in the MST-treated group were 14-fold and 11-fold higher, respectively, than those in the sesame extract-treated group. These results suggest that turmeric oil is an effective solvent to enhance the bioavailability of sesamin and sesamolin.     

Stochastic security testing of chaos‐based communication systems against error function attack

This paper proposes two stochastic testing methods for the security analysis of a secure communication scheme based on continuous‐time chaotic systems. First, we define an instantaneous EFA (error function attack) function that does not include the average operation. Second, we propose a statistical testing for cryptanalysis, which calculates a standard deviation of the EFA function obtained by random trial keys. As another stochastic testing, moreover, we propose a stochastic evolutional attack to find a secret key. Finally, simulation results for the proposed security testing are presented. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

In Vivo Electrophysiology of Peptidergic Neurons in Deep Layers of the Lumbar Spinal Cord after Optogenetic Stimulation of Hypothalamic Paraventricular Oxytocin Neurons in Rats

The spinal ejaculation generator (SEG) is located in the central gray (lamina X) of the rat lumbar spinal cord and plays a pivotal role in the ejaculatory reflex. We recently reported that SEG neurons express the oxytocin receptor and are activated by oxytocin projections from the paraventricular nucleus of hypothalamus (PVH). However, it is unknown whether the SEG responds to oxytocin in vivo. In this study, we analyzed the characteristics of the brain–spinal cord neural circuit that controls male sexual function using a newly developed in vivo electrophysiological technique. Optogenetic stimulation of the PVH of rats expressing channel rhodopsin under the oxytocin receptor promoter increased the spontaneous firing of most lamina X SEG neurons. This is the first demonstration of the in vivo electrical response from the deeper (lamina X) neurons in the spinal cord. Furthermore, we succeeded in the in vivo whole-cell recordings of lamina X neurons. In vivo whole-cell recordings may reveal the features of lamina X SEG neurons, including differences in neurotransmitters and response to stimulation. Taken together, these results suggest that in vivo electrophysiological stimulation can elucidate the neurophysiological response of a variety of spinal neurons during male sexual behavior.