Preparation of New Nitrogen-Bridged Heterocycles. 68. One-Pot Synthesis of 4-Substituted 5-Acylthieno[3,2-d]thiazole Derivatives

The reactions of 5-acyl-3-(1-pyridinio)thiophene-2-thiolates with dimethyl acetylenedicarboxylate in xylene at the reflux temperature afforded the corresponding 2-unsubstituted 5-acylthieno[3,2-d]thiazoles in 25―69% yields together with dimethyl phthalate as another fragmentation product. In a few reactions, the unexpected products, dimethyl 2-[2-acylthieno[2’,3’:2,3]-1,4-thiazino[4,5-a]pyrrol-8-ylidene]succinate derivatives, were also isolated, though their yields were very low.ArticleHETEROCYCLES. 81(1):175-184 (2010)journal articl

Search for Tetraneutron by Pion Double Charge Exchange Reaction at J-PARC

Tetraneutron ($^4n$) has come back in the limelight, because of recent observation of a candidate resonant state at RIBF. We propose to investigate the pion double charge exchange (DCX) reaction, i.e. $^4\mathrm{He}({\pi}^- , {\pi}^+)$, as an alternative way to populate tetraneutron. An intense ${\pi}^-$ beam with the kinetic energy of ~850 MeV, much higher than that in past experiments at LAMPF and TRIUMF, will open up a possibility to improve the experimental sensitivity of the formation cross section, which will be much smaller than hitherto known DCX cross sections such as $^9\mathrm{Be}({\pi}^-, {\pi}^+)^9\mathrm{He}\ (g.s.)$.Comment: 4 pages, 1 figure; proceedings of the 14th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon (MENU2016), Kyoto, Japan, 25-30 July 201

Trade effects of ASEAN-plus-China and -Japan free trade agreements by production stage and industry

This article examines the trade creation and diversion effects of ASEAN-Plus-China (ACFTA) and -Japan (AJFTA) free trade agreements with focuses on production stage and machinery industry by estimating the gravity trade model for the recent two decades between 1993 and 2015. The purpose for focusing on the trade flows by production stages (final goods and intermediate goods) and by industries (machinery and non-machinery) is to uncover the effects of ACFTA and AJFTA on the expanding international production networks in East Asia. The main findings are summarized as follows. First, regarding industry total, the trade creation effects of ACFTA and AJFTA are identified not in intermediate goods but in final goods. It might come from the larger tariff gaps between the Most Favored Nation (MFN) rates and the preferential rate for ASEAN in final goods than in intermediate goods, reflecting the structure of “tariff escalation”. Comparing the effects of ACFTA and AJFTA, the larger trade creation effects are found in ACFTA than in AJFTA, probably due to the larger tariff gaps with the higher MFN rates in China. As for machinery industry, the trade creation effects are verified on ACFTA probably due to the large tariff gaps with the still-existing high MFN in China, while no trade creation effects are found because of no tariff gaps with almost zero MFN rates in Japan

疎水性相互作用あるいは親水性相互作用を利用する コアシェル型カラムHPLC法による 水溶性ビタミン類の分離分析

This paper describes HPLC separation of water soluble vitamins such as ascorbic acid （vitamin C, VC） etc. employing the core-shell type column utilizing hydrophobic interaction and/or hydrophilic interaction. As for 12 water soluble vitamins, riboflavin （vitamin B2, VB2）,riboflavin sodium phosphate （vitamin B2 phosphate）, cyanocobalamin （vitamin B12）,hydroxocobalamin and mecobalamin were successfully separated by the reversed-phase （RP）HPLC with an ODS column employing 15 – 20 % acetonitrile（ ACN） or methanol（ MeOH） as an organic modifier. Other water soluble vitamins eluted at almost t0 （column hold up time）by the RP-HPLC with an ODS column using no addition of ACN or MeOH to the mobile phase.These seven water soluble vitamins （VC, isoascorbic acid, ascorbic acid 2-glucoside, nicotinic acid, nicotinamide, vitamin B1 and vitamin B6） were successfully separated by hydrophilic interaction chromatography（ HILIC） with an amide type column employing around 70% ACN mobile phase. The elution order in the HILIC mode was reversed compared with that in the RP-HPLC mode. Further each sample was identified more selectively by the UV spectra obtained by the photo diode array detector. Assay of pharmaceutical preparations and soft drink containing VC was successful by the HILIC mode HPLC employing an internal substance method within a short analysis time

Trade effects of ASEAN-plus-China and -Japan free trade agreements by production stage and industry

This article examines the trade creation and diversion effects of ASEAN-Plus-China (ACFTA) and -Japan (AJFTA) free trade agreements with focuses on production stage and machinery industry by estimating the gravity trade model for the recent two decades between 1993 and 2015. The purpose for focusing on the trade flows by production stages (final goods and intermediate goods) and by industries (machinery and non-machinery) is to uncover the effects of ACFTA and AJFTA on the expanding international production networks in East Asia. The main findings are summarized as follows. First, regarding industry total, the trade creation effects of ACFTA and AJFTA are identified not in intermediate goods but in final goods. It might come from the larger tariff gaps between the Most Favored Nation (MFN) rates and the preferential rate for ASEAN in final goods than in intermediate goods, reflecting the structure of “tariff escalation”. Comparing the effects of ACFTA and AJFTA, the larger trade creation effects are found in ACFTA than in AJFTA, probably due to the larger tariff gaps with the higher MFN rates in China. As for machinery industry, the trade creation effects are verified on ACFTA probably due to the large tariff gaps with the still-existing high MFN in China, while no trade creation effects are found because of no tariff gaps with almost zero MFN rates in Japan