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Tranquilan-Aranilla, C.*; Nagasawa, Naotsugu; Bayquen, A.*; Dela Rosa, A.*
Carbohydrate Polymers, 87(2), p.1810 - 1816, 2012/01
Times Cited Count：88 Percentile：95.14(Chemistry, Applied)Carboxymethyl derivatives of kappa-carrageenan (KC) with varying degrees of substitution were obtained by multi-step carboxymethylation process. The structural and chemical profiles of the derivatives were determined by FTIR, 
C NMR, gel permeation chromatography, elemental analysis, potentiometric titration and visual estimation of gelation temperature. The derivatives exhibited high degrees of substitution and acidity. However, sulfur content, molecular weight and gelation temperature were lower compared to the parent KC polymer. FTIR confirmed the presence of carboxymethyl groups in the polymer backbone while C NMR revealed that functionalization occurred at the three hydroxyl groups in KC disaccharide unit.
-carrageenan oligomers as plant growth promoterAbad, L.*; Saiki, Seiichi; Nagasawa, Naotsugu; Kudo, Hisaaki*; Katsumura, Yosuke*; Dela Rosa, A. M.*
Radiation Physics and Chemistry, 80(9), p.977 - 982, 2011/09
Times Cited Count：15 Percentile：73.97(Chemistry, Physical)The optimum molecular weight of irradiated -carrageenan for the plant growth promoting effect is known to be around 10 kDa, which is obtained by irradiation at doses of 100 kGy in solid and of 2 kGy in 1% aqueous solution. In this study, isolated fraction by membrane filter of irradiated -carrageenan was analyzed by NMR. The chemical shifts of C and 
H spectra at the range of 3-10 kDa indicated that the basic functional structure of -carrageenan (alternating D-galactose-4-sulfate and 3,6-anhydro-D-galactose dimer) remains intact. No radiolytic product having carbonyl groups was detected at the range of 3-10 kDa, and moved to less than 3 kDa probably. From these results, it is assumed that the plant growth promoting effect of irradiated -carrageenan depends on the molecular weight, its intact structure, and not on the radiolytic products.
Be halo nucleus from 
Bi at coulomb barrierMazzocco, M.*; Signorini, C.*; Romoli, M.*; De Francesco, A.*; Di Pietro, M.*; Vardaci, E.*; Yoshida, Koichi*; Yoshida, Atsushi*; Bonetti, R.*; De Rosa, A.*; et al.
European Physical Journal A, 28(3), p.295 - 299, 2006/06
Times Cited Count：46 Percentile：90.03(Physics, Nuclear)The scattering of the radioactive, weakly bound, halo nucleus Be from Bi has been studied at 40 MeV. The measurement performed with a low-intensity and a large-emittance secondary beam could be made using an extremely compact, large solid angle (
2
sr) detecting set-up, based on 8 highly segmented Si telescopes. The 
Be scattering angular distributions, as well as their relative reaction cross-sections, resulted to be rather similar. This may suggest that at Coulomb barrier energies the halo structure and the small weakly binding energy of the Be projectile have no big influence on the reaction dynamics.
Relleve, L. S.*; Yoshii, Fumio; Dela Rosa, A.*; Kume, Tamikazu
Angewandte Makromolekulare Chemie, 273, p.63 - 68, 1999/07
no abstracts in English
irradiationC.T.Aranilla*; Yoshii, Fumio; Dela-Rosa, A. M.*; Makuuchi, Keizo
Radiation Physics and Chemistry, 55(2), p.127 - 131, 1999/00
Times Cited Count：47 Percentile：94.09(Chemistry, Physical)no abstracts in English
-carrageenan for radiation crosslinkingAranilla, C. T.*; Nagasawa, Naotsugu; Dela Rosa, A. M.*; Tamada, Masao
no journal, ,
The -carrageenan (kC) who is one of the oceanic polysaccharides is chemically modified to carboxymethyl -carrageenan (CMkC). The CMkC hydrogel was synthesized by -irradiation in the paste. CMkC whose degree of substitution of the carboxymethyl group is 1.2 could be synthesized by making the monochlorinated acetate react to kC under the alkaline existence. CMkC hydrogel whose gel fraction is 6-40% could be synthesized by -irradiation with the paste of 10-40% concentration.
Nagasawa, Naotsugu; Aranilla, C. T.*; Dela Rosa, A. M.*; Tamada, Masao
no journal, ,
no abstracts in English
-carrageenan derivative for radiation crosslinkingNagasawa, Naotsugu; Aranilla, C. T.*; Dela Rosa, A. M.*; Tamada, Masao
no journal, ,
no abstracts in English
-ray irradiation and electron-beam pulse radiolysis study of -carrageenanAbad, L.*; Kudo, Hisaaki*; Saiki, Seiichi; Nagasawa, Naotsugu; Tamada, Masao; Fu, H.*; Muroya, Yusa*; Lin, M.; Katsumura, Yosuke*; Dela Rosa, A. M.*
no journal, ,
The radiation degradation yield of -carrageenan irradiated at atmospheric conditions, in vacuum and at 1% aqueous solutions was determined by GPC. UV-Vis characterization of irradiated -carrageenan for all irradiation conditions indicated a UV-Vis peak at 260nm. The rate constant of reaction of OH radicals with sonicated and irradiated -carrageenan with decreasing molecular weights were determined using e-beam pulse radiolysis.
