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711.
Ana Fernández-Jiménez Ángel Palomo Tomas Vazquez Ramesh Vallepu Tohru Terai Ko Ikeda 《Journal of the American Ceramic Society》2008,91(4):1231-1236
The present paper reports the preliminary results obtained and analyzed in the framework of a joint Spanish–Japanese project on the behavior of blends of alkali-activated metakaolin (MK) and calcium aluminate cement (CAC). In these experiments, the materials were activated with an 8 M solution of NaOH, poured into molds, and subjected to brief thermal curing (2 or 20 h at 85°C). The hardened pastes were tested for mechanical strength and characterized for mineralogy and microstructure by a number of techniques (XRD, FTIR, BSEM, and MAS-NMR). The results showed that under the above conditions, the Al and Ca in the CAC were taken up into the aluminosilicate formed as the main product of the alkali activation of MK. None of the CAC hydration compounds (CAH10 ; C2 AH8 ; C3 AH6 ; AH3 ) normally formed were detected in any of the cases studied. 相似文献
712.
Aeromonas caviae ME-1 is a multiple xylanase-producing gram-negative bacterium which was isolated from the gut contents of a wild silkworm, Samia cynthia pryeri. One of the xylanases produced by A. caviae ME-1, XynX (38 kDa, family 10 xylanase), hydrolyzes xylan to xylobiose and xylotetraose as final degradation products. Generally, xylanases are extracellular or cell surface enzymes. However, XynX is not exported to the extracellular fluid by A. caviae ME-1 and an Escherichia coli transformant harboring the xynX gene. In this study, we investigated the intracellular localization of XynX in A. caviae ME-1 and an E. coli transformant. XynX was found in the cytoplasm when the cells were grown under normal culture conditions. However, XynX was released from the cytoplasm to the periplasm during osmotic downshock. This release of XynX in the E. coli transformant was blocked in the presence of gadolinium chloride, which has been reported to be an inhibitor of bacterial mechanosensitive channels. 相似文献
713.
714.
Yan Feng Yong-Goe Joh Kazuhiko Ishikawa Hiroyasu Ishida Susumu Ando Tohru Yamagaki Hiroshi Nakanishi Shugui Cao Ikuo Matsui Yoshitsugu Kosugi 《Journal of the American Oil Chemists' Society》2000,77(11):1147-1152
Hyperthermophilic archaeon Pyrococcus horikoshii produced phospholipase A2 in a cytosolic fraction. The enzyme displayed optimal activity at 90°C and pH 7 and preferentially hydrolyzed sn-2 fatty acids in the following order: linoleoyl> oleoyl>arachidoyl phosphatidylcholine. Phospholipase A2 had similar activities toward l-α-1-palmitoyl-2-arachidoyl derivatives of phosphatidylcholine and phosphatidylethanolamine. Phospholipase A2 activity was unaffected by the addition of 0.0001–1 mM calcium, but was inhibited slightly by the addition of 2–10 mM calcium.
The activity was enhanced more than 5–18-fold in the presence of 3–20% (vol/vol) glycerol. The activity was unaffected by
the addition of 1–5 mM EDTA or 0.01–20 mM dithiothreitol. A caldarchaetidic acid derivative having a molecular weight of 1544
disappeared upon incubation of the cytosolic fraction with total lipid. The phospholipase A2 was difficult to purify by general chromatography because it existed as an aggregate. Electrophoresis was carried out using
10–15% polyacrylamide gels containing sodium dodecyl sulfate (SDS-PAGE). No activity of phospholipase A2 activity was observed in the absence of proteins less than 19 kD in size, as fractionated by SDS-PAGE.
Portions of this article were presented at the Biocatalysis Symposium at the 91st Annual Meeting and Expo of the American
Oil Chemists’ Society in San Diego, CA, April, 2000. 相似文献
715.
Yong-Ho Choa Noriko Bamba Hiroyuki Hayashi Hiroki Kondo Tohru Sekino Koichi Niihara 《Journal of Materials Science》1999,34(15):3789-3793
The deagglomeration process and its effects on the microstructure have been investigated for fine MgO, SiC powders and SiC particle added MgO mixed powders which were ball-milled under both polar- and non-polar solvent without deflocculants. During the drying, exothermic reactions are observed at 300–450 °C in MgO and SiC powders ball-milled in alcohol. On the other hand, no chemical reaction could be observed for the powders ball-milled using acetone, and nn-hexane. The observed exothermic reactions, then, are believed to be due to the oxide and/or oxide layer-alcohol reaction product formed during milling. This mechano-chemical reaction directly affects to deagglomerate during the drying process after wet-milling. Among the alcohol media, the well-dispersibility and deagglomeration of SiC powders as well as MgO powders seem to be reached by n-butyl alcohol, considering the balance between the steric effects and the dielectric constant of alcohol. These dispersion characteristics also effect on the microstructure of SiC particle dispersed MgO based composites. 相似文献
716.
Tohru Shiga Takeshi Narita Taiji Ikawa Akane Okada 《Polymer Engineering and Science》1998,38(4):693-698
Stress monitoring in thin polymer coatings was monitored using time resolved fluorescence from organic molecules. The decay time of fluorescence from an organic molecule in a uniaxially stretched polymer coating decreases with increasing tensile stress. The substance 9-methylanthracene (9-MeAn) is an effective dye for detecting internal stresses up to 10 MPa. Compared with the traditional bimetallic method, time resolved fluorescence of 9-MeAn gave reliable values for internal stresses in a thin polymer coating. The internal stress in a polymer coating cured on a glass plate was measured during exposure to an outdoor weathering test. The internal stress diminished significantly in three days. The decrease in the internal stress was caused mainly by light irradiation. Because 9-MeAn degraded in sunlight, it was a useful probe for stress monitoring only for periods less than two weeks. 相似文献
717.
Yoshizumi Serizawa Kazunori Kitamura Masanori Myoujin Tohru Matsushima 《Electrical Engineering in Japan》2000,132(2):39-48
In this paper we propose a simplified SDH (Synchronous Digital Hierarchy)‐based time synchronous system that does not require the modification of existing SDH transmission equipment (STE) and clock supply equipment (CSE). The system has auxiliary time synchronizing equipment (TSE) attached to existing STE and CSE and can be expanded in a cascade and branch manner, where frequency and time are separately synchronized, and which enables us to partially time‐synchronize an SDH network or to introduce a time transfer network locally. Experimental time synchronizing devices using a 576‐kbps data communication channel (DCC) in the section overhead (SOH) showed potentially satisfactory performance, with synchronization errors of a four‐link system on the order of submicroseconds. Noise analyses of experimental TSE, DCC, CSE, and optical links showed that accuracy on the order of microseconds can be achieved. © 2000 Scripta Technica, Electr Eng Jpn, 132(2): 39–48, 2000 相似文献
718.
Mustafa T Ardah Nabil Eid Tohru Kitada M. Emdadul Haque 《International journal of molecular sciences》2021,22(24)
Parkinson’s disease (PD) is a neurodegenerative disease characterized by the loss of dopamine neurons and the deposition of misfolded proteins known as Lewy bodies (LBs), which contain α-synuclein (α-syn). The causes and molecular mechanisms of PD are not clearly understood to date. However, misfolded proteins, oxidative stress, and impaired autophagy are believed to play important roles in the pathogenesis of PD. Importantly, α-syn is considered a key player in the development of PD. The present study aimed to assess the role of Ellagic acid (EA), a polyphenol found in many fruits, on α-syn aggregation and toxicity. Using thioflavin and seeding polymerization assays, in addition to electron microscopy, we found that EA could dramatically reduce α-syn aggregation. Moreover, EA significantly mitigated the aggregated α-syn-induced toxicity in SH-SY5Y cells and thus enhanced their viability. Mechanistically, these cytoprotective effects of EA are mediated by the suppression of apoptotic proteins BAX and p53 and a concomitant increase in the anti-apoptotic protein, BCL-2. Interestingly, EA was able to activate autophagy in SH-SY5Y cells, as evidenced by normalized/enhanced expression of LC3-II, p62, and pAKT. Together, our findings suggest that EA may attenuate α-syn toxicity by preventing aggregation and improving viability by restoring autophagy and suppressing apoptosis. 相似文献
719.