Electron paramagnetic resonance measurements revealed a ferromagnetic phase transition taking place near room temperature in quasi-two-dimensional dodecylamine-intercalated vanadium pentoxide with a mixed structure of coexisting lamellar and rectangular phases. It is shown that the ferromagnetism can be ascribed to the rectangular phase, whereas the paramagnetic lamellar phase undergoes no magnetic transition. 相似文献
Summary: Fuel cells were designed for high temperature operations. Poly[2,2′‐(m‐phenylene)‐5,5′‐bibenzimidazole] (PBI) was synthesized in a solution of P2O5, CH3SO3H, and CF3SO3H. The PBI was dissolved in a mixture of CF3CO2H and H3PO4 and the solution was used for the preparation of Pt catalyst slurry for membrane electrode assembly. The single cell showed a current density of 280 mA · cm−2 at a cell voltage of 0.5 V with feeds of H2 and O2 at 160 °C and without external humidification.
The direct sulfonylation of 4,5‐dichloropyridazin‐3‐ones with some benzenesulfonyl chlorides in the presence of base in tetrahydrofuran gave only the corresponding N‐sulfonylated product. The reaction of 2‐benzenesulfonyl‐4,5‐dichloropyridazin‐3‐ones with some aliphatic amines under neutral conditions afforded 5‐alkylamino‐2‐benzenesulfonyl‐4‐chloropyridazin‐3‐ones and/or the corresponding N‐alkyl‐benzenesulfonamides. 相似文献
Functionalization of 4,5-dihalopyridazin-6-ones using 1-(1,1-dibromo-2-oxopropyl)-4,5-dihalopyridazin-6-ones with some nucleophiles gave regioselectively only 5-halo-4-substituted-pyridazin-6-ones. 相似文献
Recombinant DNA technology and protein engineering are currently utilized in the cost-effective production of pharmaceutical and industrial proteins with native conformation. Escherichia coli retains its dominant position as the first choice of host for speed, simplicity and well-established production protocols. However, protein production using recombinant E. coli occasionally encounters complex purification and refolding steps. This paper introduces an efficient scheme for purification andin vitro refolding of industrially important proteins including cyclodextrin glycosyltransferase (CGTase) expressed in recombinant E. coli employing a polycationic amino acid fusion system. Fusion of polycationic amino acids to CGTase allowed purification and refolding of CGTase to be simple and efficient. A novel CGTase production strategy will be discussed by considering recent progress in protein purification and refolding techniques. 相似文献
Previous studies have demonstrated that rottlerin, a specific PKCdelta inhibitor, potentiates death receptor- mediated apoptosis through a cytochrome c-dependent or -independent pathway. However, its ability to regulate necrotic cell death, as well as the underlying mechanism, remains unknown. We found that in murine fibrosarcoma L929 cells, treatment with rottlerin protected the cells against TNF-induced necrosis, whereas it sensitized the cells to apoptosis induced by co-treatment with Hsp90 inhibitor geldanamycin and TNF, in a manner independent of its ability to inhibit PKC-delta. TNF treatment induced rapid accumulation of mitochondrial superoxide (O2-) through the Nox1 NADPH oxidase when cells undergo necrosis. Moreover, pretreatment with rottlerin failed to induce the GTP-bound form of small GTPase Rac1 by TNF treatment, and subsequently suppressed mitochondrial O2- production and poly(ADP-ribose) polymerase activation, thus inhibiting necrotic cell death. Therefore, our study suggests that Nox1 NADPH oxidase is a new molecular target for anti-necrotic activity of rottlerin upon death-receptor ligation. 相似文献
The effect of fuel burn-up on the radioactivation behavior of cladding hull materials was investigated using the ORIGEN-S code for various materials of Zircaloy-4, Zirlo, HANA-4, and HANA-6 and for various fuel burn-ups of 30, 45, 60, and 75 GWD/MTU. The Zircaloy-4 material is the only one that does not contain Nb as an alloy constituent, and it was revealed that 125Sb, 125mTe, and 55Fe are the major sources of radioactivity. On the other hand, 93mNb was identified as the most radioactive nuclide for the other materials although minor radioactive nuclides varied owing to their different initial constituents. The radioactivity of 94Nb was of particular focus owing to its acceptance limit against a Korean intermediate-/low-level waste repository. The radioactivation calculation results revealed that only Zircaloy-4 is acceptable for the Korean repository, while the other materials required at least 4,900 of Nb decontamination factor owing to the high radioactivity of 94Nb regardless of the fuel burn-up. A discussion was also made on the feasibility of Zr recovery methods (chlorination and electrorefining) for selective recovery of Zr so that it can be disposed of in the Korean repository. 相似文献