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101.
Nobuyuki Gokon Hiroko Murayama Jun Umeda Tsuyoshi Hatamachi Tatsuya Kodama 《International Journal of Hydrogen Energy》2009
Two-step thermochemical water-splitting using monoclinic ZrO2-supported Fe3O4 (Fe3O4/m-ZrO2) for hydrogen production was examined at high thermal reduction temperatures of 1400–1600 °C. After thermal reduction of Fe3O4/m-ZrO2, the reduced sample was quenched in liquid nitrogen, and was subsequently subjected to the water-decomposition step at 1000 °C. Quenching of the solid sample was conducted for analysis of the chemical reactions, such as phase transitions, occurring at high-temperature. The hydrogen productivity of Fe3O4 on a m-ZrO2 support and the conversion of Fe3O4 to FeO were significantly enhanced with higher thermal reduction temperatures. The Fe3O4-to-FeO conversion reached 60% when the Fe3O4/m-ZrO2 was thermally reduced at 1600 °C. The phase transition of m-ZrO2 support to tetragonal ZrO2 (t-ZrO2) did not occur during the thermal reduction at 1400–1500 °C, but it did proceed slightly at 1600 °C. Fe ions from Fe3O4 did not enter the ZrO2 lattice during high-temperature thermal reduction. Thus, the Fe3O4 loaded on a m-ZrO2 support can continuously contribute as a Fe3O4–FeO redox reactant for thermochemical water-splitting at high-temperatures of 1400–1600 °C. 相似文献
102.
Isolation and Identification of Antihypertensive Peptides from Antarctic Krill Tail Meat Hydrolysate 总被引:2,自引:0,他引:2
Akimasa Hatanaka Hiroko Miyahara Ken Ichi Suzuki Seizo Sato 《Journal of food science》2009,74(4):H116-H120
ABSTRACT: Antarctic krill ( Euphausia superba ) obtained from the huge biomass in Antarctic waters is an important food product in Japan. Antarctic krill peptide powder (AKPP) prepared from the tail meat by enzymatic hydrolysis significantly decreased the systolic blood pressure in spontaneously hypertensive rats by a single oral administration (1, 10, or 100 mg). Presumably, the effect of AKPP was through inhibition of the conversion of angiotensin, which mediates blood pressure elevation, from its inactive propeptide to the mature angiotensin. Two potent angiotensin I-converting enzyme (ACE) inhibitory peptides were isolated from AKPP by high-performance liquid chromatography (HPLC) and identified as Val-Trp (IC50 = 2.75 μg/mL; 12.9 μM) and Leu-Lys-Tyr (IC50 = 4.26 μg/mL; 10.1 μM). Val-Trp and Leu-Lys-Tyr comprised 0.025%± 0.0023% (w/w) and 0.018%± 0.0023% (w/w) of AKPP, respectively, as measured by electrospray ionization mass spectrometry (ESI-MS). The contributions of Val-Trp and Leu-Lys-Tyr to the ACE inhibitor activity of AKPP were 17.7%± 1.60% and 8.04%± 1.03%, respectively, suggesting that these 2 peptides constitute a substantial portion of the overall ACE inhibitor potential of AKPP. 相似文献
103.
Hayashida T Ueda M Aiura K Tada H Onizuka M Seno M Yamada H Kitajima M 《Protein engineering, design & selection : PEDS》2005,18(7):321-327
Human pancreatic ribonuclease-1 (RNase1) does not exhibit its cytotoxicity unless it is artificially internalized into the cytosol. Furthermore, once it encounters the cytosolic RNase inhibitor (RI), the activity of RNase1 is seriously reduced. To achieve the cellular targeting of RNase1 and the blocking of RI binding simultaneously, the basic fibroblast growth factor (bFGF) sequence was inserted into RNase1 at the RI binding site using a gene fusion technique. The effect of this fusion protein, CL-RFN89, on the angiogenesis, which was accelerated by FGF-FGF receptor interaction, was investigated. It was shown by using fluorescein-labeled CL-RFN89, that the binding to human umbilical vein endothelial cells (HUVECs) was dependent on the existence of the FGF receptors. In addition, CL-RFN89 inhibited the cellular growth of HUVECs in vitro and also inhibited the tube formation, using a three-dimensional tube formation assay. Furthermore, this fusion protein was shown to prevent in vivo tumor cell-induced angiogenesis, using the mouse dorsal air sac assay. These results demonstrated that CL-RFN89 inhibits angiogenesis in vitro and in vivo and that it can be expected to be a potent antiangiogenic agent. 相似文献
104.
Takahide Nomura Masakatsu Tachibana Hiroko Nomura Masaru Chihara Yasumichi Hagino 《Lipids》1987,22(7):474-479
Studies were conducted to compare the metabolic effects of vasopressin, 4β-phorbol-12-myristate-13-acetate (PMA) and A23187
on ketogenesis and oleate metabolism in isolated hepatocytes from fed rats. Vasopressin inhibited the formation of acid-soluble
products from [1-14C]oleate (0.25 mM, 0.5 mM and 1 mM), the inhibition being most marked at low (0.25 mM) concentration of oleate. Conversion
of [1-14C]oleate into14CO2 and esterified products was stimulated by vasopressin. The stimulatory effect of this hormone on14CO2 production was most marked at high (1 mM) concentration of oleate, whereas that on [1-14C]-oleate esterification was most marked at low (0.25 mM) concentration of oleate. These vasopressin actions were abolished
when hepatocytes were incubated in the absence of calcium in the medium. Our results strongly suggest that both increase in
esterification and increase in oxidation to CO2 contribute to the anti-ketogenic action of vasopressin when oleate is added as substrate, although the relative extent of
their contribution varies according to the oleate concentration. The anti-ketogenic action of vasopressin was mimicked by
PMA but not by A23187. PMA also caused a stimulation of [1-14C]oleate esterification although the effect was diminished at 1 mM [1-14C]oleate. A23187 failed to affect [1-14C]oleate esterification. The metabolic effects of PMA were elicited in the absence of extracellular calcium, too. Conversion
of [1-14C]oleate into14CO2 was only slightly increased by both PMA and A23187 when 1 mM [1-14C]oleate was added as substrate. The marked stimulatory effect of vasopressin on14CO2 production from [1-14C]oleate was not reproduced even by the combination of PMA and A23187. The possible involvement of protein kinase C and calcium
mobilization in the regulation of oleate metabolism is discussed. 相似文献
105.
A 532 nm red pigment formed in the thiobarbituric acid (TBA) assay of human urine was characterized after separation of the
pigment by high-performance liquid chromatography. The yield of the red pigment was some-what higher at pH 2 than at pH 5;
its development was not inhibited by ethylenediaminetetraacetic acid. The characteristics of the pigment were similar to those
of the pigment derived from standard malonaldehyde. The amount of the pigment formed was roughly equal to the content of malonaldehyde
derivatives estimated as 1-(2,4-dinitrophenyl)pyrazole. Pigment formation was significantly enhanced byt-butyl hydroperoxide (t-BuOOH) and ferric ions, which may be due to pigment formed from aldehydes other than malonaldehyde; the presence of these
aldehydes was confirmed by the formation of the corresponding 2,4-dinitrophenylhydrazones. The amount of pigment produced
from 24-h urine samples of 12 healthy subjects was estimated to be 26–95 nmol/kg, and 65–182 nmol/kg in the presence oft-BuOOH. These values are lower than those for urine of rabbit or rat. The TBA reactivity in the absence and presence oft-BuOOH of human urine was not related to age or sex. The TBA reactivity of human urine collected in the afternoon and in the
evening was higher than that of urine collected in the morning. 相似文献
106.
K Ido T Suzuki Y Taniguchi C Kawamoto N Isoda N Nagamine T Ioka K Kimura M Kumagai Y Hirayama 《Canadian Metallurgical Quarterly》1995,42(2):151-155
Venous stasis of the legs during laparoscopic cholecystectomy was compared between patients without graded compression leg bandages (Group 1; n = 12) and patients with such bandages (Group 2; n = 12) by measuring mean blood flow velocity and cross-sectional area of the femoral vein using a color Doppler ultrasonography. In Group 1, when velocity and area were measured in the supine position, a significant decrease in velocity (p < .05) and a significant increase in area (p < .05) occurred after abdominal insufflation to 10 mm Hg. These changes were greater during abdominal insufflation in the reverse Trendelenburg position than during abdominal insufflation in the supine position. In Group 2, flow velocity was significantly higher (p < .05) before abdominal insufflation as compared with Group 1. After abdominal insufflation to 10 mm Hg and a postural change, velocity significantly decreased (p < .05) and area significantly increased (p < .05) in Group 2, similar to the results in Group 1. During abdominal insufflation at 5 mm Hg or lower, the use of the graded compression bandage was found to be useful for preventing femoral vein stasis. During abdominal insufflation at 10 mm Hg or in the reverse Trendelenburg position, the bandage did not prevent femoral vein stasis. 相似文献
107.
This study considered an information presentation method to help customers make a concept-articulation type of purchase. When
customers follow the concept-articulation type of thinking, they only have vague requirements and try to make a gradual clarification
of what they really want through the interaction with salesclerk(s). Skillful salesclerks can communicate with their customers
appropriately to discover an opportunity for bringing the customers to their concept-articulation, which often leads to a
successful sale. Based on the observations from our analysis of these human behavior in actual purchase activities, we constructed
a system called S-Conart (Concept Articulator for Shoppers) to support the concept-articulation type of purchase. The user
study conducted using S-Conart shows that using a different method of presenting information can cause a change in the user’s
mental world, which is also observed in a real-life shopping situation, although in a different form. The result of this user
study suggests the possibility of chance discovery by customers themselves, which is expected to be useful for building support
systems for concept-articulation type of shoppers.
Hiroko Shoji: She is an associate professor in the Department of Information and Communication Sciences at Kawamura Gakuen Women’s University,
and also a doctoral student in the Department of Advanced Interdisciplinary Studies at the University of Tokyo. She received
her B.S. in mechanical engineering in 1989 and her M.Eng. in mechanical engineering and engineering synthesis in 1991 from
the University of Tokyo. Her current research interests include creativity in real life and chance discovery. She was awarded
a Research Promotion Award from Japanese Society for Artificial Intelligence (JSAI) in 2000.
Koichi Hori, D.Eng.: He received his B.Eng, M.Eng, and Dr.Eng. degrees in electronic engineering from the University of Tokyo, in 1979, 1981,
and 1984, respectively. In 1984, he joined National Institute of Japanese Literature, where he developed AI systems for literature
studies. Since 1988, he has been with the University of Tokyo. He is currently a professor with Department of Advanced Interdisciplinary
Studies, the University of Tokyo. From September 1989 to January 1990, he also held a visiting position at University of Compiegne,
France. His current research interests include AI technology for supporting human creative activities, cognitive engineering
and Intelligent CAD systems. Professor Hori is a member of IEEE, ACM, IEICE, IPSJ, JSAI, JSSST, and JCSS. 相似文献
108.
This paper describes an on-chip-type electrochemical flow immunoassay system with a multichanneled matrix column. The multichanneled matrix column was functionally coated with cation-exchange resin and used for separation of proteins. Antihistamine immunoglobulin G (IgG) antibody conjugated with ferrocenemonocarboxylic acid (Fc) was also prepared and used as a novel analytical reagent. Antibody-antigen complexes were separated from free Fc-conjugated IgG antibody (Fc-IgG) on the basis of differences in isoelectric point (pI) using the multichanneled matrix column coated with cation-exchange resin. The assay yields a good relationship between current and histamine concentration in the range of 200-2000 ng/mL. This simple technique enables the assay of histamine released in whole blood within 2 min. Furthermore, a good correlation was found between the response of the electrochemical immunoassay described in this paper and the conventional RIA (radioimmunoassay). This on-chip-type electrochemical flow immunoassay requires only minute quantities of whole blood samples and generates highly reproducible results. 相似文献
109.
Arata T Nakamura M Ueki S Sugata K Aihara T Ueda K Yasuda S Narumi R Kusuhara H Yamamoto Y 《Journal of electron microscopy》2005,54(Z1):i47-i51
We have studied biological nano-machines, motor and switch proteins operating as supramolecular complexes by electron spin resonance (ESR) and found key features of their molecular movements. In all the systems, the specific movements of elements or domains were detected and quite dynamic at nanometer scale. We have observed two broad but distinct orientations, separated by a 25 degrees axial rotation, of a spin label attached specifically to the light chain (LC) domain of myosin motor in the muscle fibers. The distribution became only narrower upon muscle activation. ESR spectrum from the spin label of the neck-linker of dimeric kinesin motor consisted of immobilized and mobilized components and did not exhibit nucleotide-dependent mobility change. The distance between two labels of kinesin dimer was also measured by spin dipole-dipole interaction, showing a broad distribution and a nucleotide-dependent change on the nanometer scale (>1.5 nm). These results suggest that two LC domains of myosin and two neck linkers of kinesin play a similar role for sliding movement using two conformations. The spin label of the skeletal (Tn)-I regulatory domain (TnIreg) showed a large mobility change by Ca2+ ion suggesting a Ca-induced switch movement of TnIreg. Spin dipole-dipole interaction showed that in reconstituted muscle fibers both skeletal and cardiac TnC undergo Ca2+-induced structural change that is thought to be essential for TnIreg movement. We also succeeded in fixing the newly-synthesized bifunctional spin label rigidly on the TnC molecule in solution, indicating that we can determine the precise coordinate of the spin principal axis of troponin on the oriented filament. 相似文献
110.
Two polyanions and two polycations were prepared by the esterification of poly(vinyl alcohol). Properties of their neutral polyelectrolyte complex membranes were compared with those of polyelectrolyte membranes. The charged state on the membranes was related closely to the mechanochemical reaction, the salt rejection, and the solution permeability. Both the salt rejection and the water flux of neutral polyelectrolyte complex memberanes were lower than those of the corresponding acidic or basic complex membranes. 相似文献