Antimutagenic effects of a novel lipophilic antioxidant, 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), and other known antioxidants against heterocyclic amine- or other mutagen-induced mutagenesis were examined in the Ames assay using Salmonella strain TA 98 to access the chemo-preventive effects of antioxidants on heterocyclic amine-induced carcinogenesis. Further the mechanisms of inhibition by HTHQ were accessed. HTHQ was shown to potently inhibit mutagenesis induced by all of 8 different heterocyclic amines at rates between 100% and 63% in the presence of S9 mix. When the protection of HTHQ against 2-amino-6- methyldipyrido[1,2-alpha:3',2'-d]imidazole (Glu-P-1)-induced mutagenesis was compared with known antioxidants t-butylhydroquinone, propyl gallate, BHA, BHT and alpha-tocopherol, HTHQ showed the greatest effect. Among hexyl, butyl, ethyl and methyl derivatives of 1-O-alkyl-2,3,5-trimethylhydroquinone, HTHQ was the most effective in inhibiting Glu-P-1-, 3-amino-1-methyl-5-H-pyrido[4,3-b]indole (Trp-P-2)- or 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-induced mutagenesis. On the other hand, HTHQ did not inhibit mutagenic activity induced by other mutagens such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2) and benzo[a]pyrene. HTHQ weakly inhibited that due to direct mutagen 2-nitro derivative of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) only in the presence of S9 mix. No such influence on a 2-nitro derivative of 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mutagenesis, was observed with or without the S9 mix. HTHQ slightly inhibited mutagenesis induced by activated Glu-P-1, a direct acting proximate metabolite of Glu-P-1, in the absence of the S9 mix. HPLC analysis revealed activated Glu-P-1 to be formed by incubating Glu-P-1 with the S9 mix, but this was considerably decreased by the addition of HTHQ. These results indicate that HTHQ is a powerful antimutagenic compound and specifically acts against heterocyclic amines. Its antimutagenic activity appeared to exert by both inhibiting metabolic activation of heterocyclic amines and action on activated N-hydroxy species.

The tunnel field-effect transistor (FET) has emerged as an attractive candidate for next-generation low-power-consuming devices. In tunnel FETs, a steep subthreshold slope (SS) and a low off-current are expected. However, the tunnel FETs have a lower on-current than conventional MOSFETs. To obtain a high on-current, the use of a heterojunction at the location of tunneling is effective. In this study, we confirmed that it was indeed effective to use heterojunctions for the tunnel FETs, and we revealed the dependences of SS and on-current on two parameters, namely, the equivalent oxide thickness (EOT) and body width, in the GaAsSb/InGaAs tunnel FET by a simulation study. We also verified the results experimentally.

Biochemical examinations of a hyalinized skin tumor of systemic hyalinosis (juvenile hyaline fibromatosis) revealed an increase in chrondroitin sulfate synthesis by skin fibroblasts with an enlarged, rough surfaced endoplasmic reticulum as well as an increase in chondroitin sulfate content. Thse results indicate that systemic hyalinosis is a connective tissue disorder characterized by abnormal GAG synthesis of fibroblasts.

We performed trajectory analysis of beam ions in such a magnetic field structure having a weak magnetic field region over a wide range by canceling the magnetic field created by the solenoid coil with a Helmholtz coil. The rate at which the beam ions injected in the axial direction are trapped in the magnetic field structure is statistically examined. In addition, by adjusting the Helmholtz coil current, the position of the field-null point is changed, and the influence on the ion trapping rate is also investigated. As a result, it is found that the larger the beam dispersion, the higher the trapping rate, and the higher the energy, the lower the trapping rate. Furthermore, it is also found that in the case where the magnetic field is not completely canceled at the center of the device, there is an energy which extremely decreases the trapping rate.

In this paper, we propose a method to classify the tunneling currents using simulations. The main objective is to investigate the effects of the direct source-to-drain tunneling, which is undesirable, in the case of devices with extremely short channels. We performed the classification of tunneling currents in InGaAs/GaAsSb heterojunction double-gate tunnel FETs based on this method, and we found that the direct-tunneling component increased dramatically in short-channel cases. The channel length must be 20 nm or longer, in case of InGaAs/GaAsSb heterojunction double-gate tunnel FETs, to limit the off-current within 10 pA/µm, which is required as per the ITRS LP.