Neutron activation analysis of a particle returned from asteroid Itokawa     

Ebihara M  Sekimoto S  Shirai N  Hamajima Y  Yamamoto M  Kumagai K  Oura Y  Ireland TR  Kitajima F  Nagao K  Nakamura T  Naraoka H  Noguchi T  Okazaki R  Tsuchiyama A  Uesugi M  Yurimoto H  Zolensky ME  Abe M  Fujimura A  Mukai T  Yada Y 《Science (New York, N.Y.)》2011,333(6046):1119-1121

A single grain (~3 micrograms) returned by the Hayabusa spacecraft was analyzed by neutron activation analysis. This grain is mainly composed of olivine with minor amounts of plagioclase, troilite, and metal. Our results establish that the Itokawa sample has similar chemical characteristics (iron/scandium and nickel/cobalt ratios) to chondrites, confirming that this grain is extraterrestrial in origin and has primitive chemical compositions. Estimated iridium/nickel and iridium/cobalt ratios for metal in the Itokawa samples are about five times lower than CI carbonaceous chondrite values. A similar depletion of iridium was observed in chondrule metals of ordinary chondrites. These metals must have condensed from the nebular where refractory siderophile elements already condensed and were segregated.  相似文献   

The Politics of Regional Cooperation on Acid Rain Control in East Asia     

Wakana Takahashi  Jusen Asuka 《Water, air, and soil pollution》2001,130(1-4):1837-1842

Several multilateral initiatives on acid rain control were advocated in the 1990s, and extended through multiple channels in East Asia. There is, however, little coordination between those initiatives. The geopolitical make-up of the region has also hampered further progress in regional cooperation on the issue. In this paper we first examine the major features and weaknesses of existing regional environmental cooperative schemes. Second, we review collective initiatives on the acid rain issue, and examine how further progress has been hindered by the inherent inadequacies of the schemes. Finally, we consider whether and how regional cooperation on the acid rain issue may be promoted, and try to draw some implications from the European experience that might help enhance regional cooperation.  相似文献   

Preparation of phytate-removed deamidated soybean globulins by ion exchangers and characterization of their calcium-binding ability.   总被引：3，自引：0，他引：3  

Hitomi Kumagai  Shigeo Ishida  Atsushi Koizumi  Hidetoshi Sakurai  Hitoshi Kumagai 《Journal of agricultural and food chemistry》2002,50(1):172-176

Phytate-removed deamidated soybean globulins were prepared using ion-exchange resins to provide them with a functional property to enhance calcium absorption in the body. The phosphorus level was reduced from 45 to 20 micromol/g using 0.05 g/mL of AE-4, an anion-exchange resin with a (2-hydroxyethyl)dimethylammonium group, in 0.2% soybean globulin solution for 1 h at 4 degrees C, and 90-92% of the phosphorus in defatted soybeans could be removed. As for deamidation, CE-4, a cation-exchange resin of the carboxylate type, showed a much higher deamidation activity than CE-1 and CE-2, cation-exchange resins of the sulfonate type. No peptide bond hydrolysis was observed for any cation-exchange resin treated at 4 degrees C. There was no significant difference in the amount of acid amide deamidated at temperatures between 4 and 50 degrees C. The deamidation level was able to increase to 73% using 0.10 g/mL of CE-4 in a 0.2% soybean globulin solution for 6 h at 4 degrees C. The amount of calcium bound to the soybean globulins decreased with removal of the phytate but increased with deamidation.  相似文献   

Effect of 3-O-octanoyl-(+)-catechin on the responses of GABA(A) receptors and Na+/glucose cotransporters expressed in xenopus oocytes and on the oocyte membrane potential     

Aoshima H  Okita Y  Hossain SJ  Fukue K  Mito M  Orihara Y  Yokoyama T  Yamada M  Kumagai A  Nagaoka Y  Uesato S  Hara Y 《Journal of agricultural and food chemistry》2005,53(6):1955-1959

Recently, 3-O-octanoyl-(+)-catechin (OC) was synthesized from (+)-catechin (C) by incorporation of an octanoyl chain into C in the light of (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), which are the major polyphenols found in green tea and have strong physiological activities. OC was found to inhibit the response of ionotropic gamma-aminobutyric acid (GABA) receptors (GABA(A) receptors) and Na+/glucose cotransporters expressed in Xenopus oocytes in a noncompetitive manner more strongly than does C. OC also induced a nonspecific membrane current and decreased the membrane potential of the oocyte, and thus death of the oocyte occurred even at lower concentrations than that induced by C or EGCg. Although EGCg produced H2O2 in aqueous solution, OC did not. This newly synthesized catechin derivative OC possibly binds to the lipid membrane more strongly than does C, Ecg, or EGCg and as a result perturbs the membrane structure.  相似文献   

Oxidative dimers produced from protocatechuic and gallic esters in the DPPH radical scavenging reaction     

Kawabata J  Okamoto Y  Kodama A  Makimoto T  Kasai T 《Journal of agricultural and food chemistry》2002,50(19):5468-5471

DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging reactions of protocatechuic and gallic acids, and their methyl esters, have been investigated by NMR. In acetone, methyl protocatechuate was gradually converted to a Diels-Alder adduct of two molecules of the intermediate quinone in the reaction with DPPH radical, whereas methyl gallate rapidly gave a symmetrical dimer via a putative quinone precursor. Both dimers are rather unstable and their structures have been deduced by in situ NMR measurements of the reaction mixtures. Gallic acid also gave a corresponding symmetrical dimer in the same reaction as methyl gallate, although protocatechuquinone produced from protocatechuic acid did not yield a Diels-Alder adduct, unlike its methyl ester. Interestingly, these dimer formations were not observed in methanol solution.  相似文献   

Analysis of properties of monoclonal antibodies to transmissible gastroenteritis virus using TO-163 strain     

E Honda  H Kanemaru  X Y Dong  M Ikuma  Y Somura  I Shibata  K Okazaki  T Kumagai 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1990,37(9):660-667

Nineteen monoclonal antibodies (MAbs), reactive in enzyme-linked immunosorbent assay (ELISA), with porcine transmissible gastroenteritis (TGE) virus TO-163 were obtained. Of these MAbs, 5 showed neutralizing (NT) activity (x 3,200 to 25,600) against TO-163. One of the MAbs which had NT activity showed hemagglutination inhibition activity (x 5,120) too. 14 hybridomas of polypeptide specificity against TO-163 strain were developed from which 11, 2, and 1 were specific for protein E2, N, and E1, respectively. Immunofluorescence staining patterns in TGE virus-infected cells reacted with MAbs were divided into three groups (types I, II and III). The fluorescence staining of E2 specific MAbs having NT activity were limited to the perinuclear area. All MAbs having NT activity showed the same fluorescence staining pattern.  相似文献   

Detection of bovine rhinotracheitis virus antibody by neutralizing test and ELISA in experimentally infected rabbits.     

E Honda  T Taniguchi  M Watanabe  T Kumagai 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1991,38(1):55-59

The antibody response of rabbit to infectious bovine rhinotracheitis (IBR) virus was examined. Two rabbits were inoculated with IBR virus strain Los Angeles into the trachea and intravenously, and intravenously two times, respectively. The patterns of antibody titers in the rabbits measured by neutralization test and ELISA were similar to those in the case of bovine. The antibody was detected after the inoculation, and much more antibody was detected after the second inoculation. The fact suggests that rabbits are a very useful laboratory animal for IBR virus infection studies.  相似文献   

Experimental infection of pregnant goats with swine fever virus     

M Shimizu  T Kumagai 《Veterinary microbiology》1989,20(3):207-214

Thirteen pregnant goats were inoculated intravenously with the ALD strain of virulent swine fever (SF) virus on Days 64-84 of gestation. Dams showed transient and mild viremia, and produced high serum neutralizing (SN) antibody after inoculation. Six inoculated dams were reared until parturition occurred and bore six apparently normal, one apparently normal but dead, one mummified and three edematous kids. Neutralizing antibody was demonstrated in the pre-colostral sera obtained from all normal kids, but no SF virus was isolated from any of them. The other seven dams were killed on post-inoculation days (PID) 5-61, and fetuses, placenta and amnion were tested for the virus and SN antibody. All fetuses of five dams examined within PID 40 were positive for SF virus, but negative for SN antibody. SF virus was also isolated from one of three fetuses examined on PID 61. Conversely, the other two fetuses examined on PID 61 were negative for SF virus, but positive for SN antibody. Furthermore, SF virus was isolated from the placenta and amnion of all the dams.  相似文献   

Small molecule lactoferrin with an inflammatory effect but no apparent antibacterial activity in mastitic mammary gland secretion     

Komine K  Komine Y  Kuroishi T  Kobayashi J  Obara Y  Kumagai K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(7):667-677

We have identified various lactoferrin (Lf) molecules in mastitic mammary gland secretions (MGSs), and these Lf molecules were examined for their physiological function in MG. These Lf molecules were isolated by Con A affinity chromatography, and then analyzed by various electrophoresis methods and N-terminal amino acid sequencing. The low Con A affinity Lf was found to have low molecular peptides as compared with the 86 kDa of the high Con A affinity Lf, which is usually detected in healthy MGSs. The N-terminal amino acid sequence of each of the small molecular Lfs were confirmed as fragments of 86 kDa Lf. This low Con A affinity Lf stimulated spleen adherent cells to produce more O(2)(-) than 86 kDa Lf. Furthermore, the low Con A affinity Lf showed low antibacterial activity against E. coli and S. aureus, and had decreased iron-binding capacity in comparison with 86 kDa Lf. Moreover, the 86 kDa Lf could stimulate bovine T cells or macrophages to produce IFN-gamma, IL-4, IL-6, and IL-1alpha. However low Con A affinity Lf induced the production of TNFalpha, but not physiological T cell or macrophage cytokines. It was also found that when the healthy MGs of dry cows were injected with the low Con A affinity Lf, there was an increase in polymorphonuclear cells together with TNFalpha, MCP-1, and IL-8 production. These results suggested that low Con A affinity Lf in mastitic MGSs differed from 86 kDa Lf in physiological characteristics, and, that it induced an inflammatory reaction in MGs.  相似文献   

Enzyme-linked immunosorbent assay for detection of canine chromogranin A by use of immunological cross-reactivity of rabbit anti-bovine chromogranin A antibody     

Akiyoshi H  Aoki M  Kumagai D  Saleh N  Noda K  Shimada T  Sugii S  Ohashi F 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(5):535-537

Bovine and canine chromogranin A were extracted and purified from each specie's adrenal glands. Isolated bovine 70 kDa protein showed 100% identity to bovine CgA reported previously, whereas isolated canine 68 kDa protein showed 83.3% identity to bovine CgA by the NH(2)-terminal amino acid sequence analysis. Rabbit antibody to purified bovine protein (CgA) was found to immunologically cross-reacted with purified canine protein (CgA). In sandwich ELISA with anti-bovine CgA, concentration-dependent curves were obtained ranging from 0.3 to 20 mug/ml for canine CgA. From these findings, sandwich ELISA with anti-bovine CgA is found to be useful to determine the concentration of canine CgA.  相似文献