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571.
Kenji Watanabe Shuichi Shibuya Yusuke Ozawa Toshihiko Toda Takahiko Shimizu 《International journal of molecular sciences》2021,22(7)
Intracellular superoxide dismutases (SODs) maintain tissue homeostasis via superoxide metabolism. We previously reported that intracellular reactive oxygen species (ROS), including superoxide accumulation caused by cytoplasmic SOD (SOD1) or mitochondrial SOD (SOD2) insufficiency, induced p53 activation in cells. SOD1 loss also induced several age-related pathological changes associated with increased oxidative molecules in mice. To evaluate the contribution of p53 activation for SOD1 knockout (KO) (Sod1−/−) mice, we generated SOD1 and p53 KO (double-knockout (DKO)) mice. DKO fibroblasts showed increased cell viability with decreased apoptosis compared with Sod1−/− fibroblasts. In vivo experiments revealed that p53 insufficiency was not a great contributor to aging-like tissue changes but accelerated tumorigenesis in Sod1−/− mice. Furthermore, p53 loss failed to improve dilated cardiomyopathy or the survival in heart-specific SOD2 conditional KO mice. These data indicated that p53 regulated ROS-mediated apoptotic cell death and tumorigenesis but not ROS-mediated tissue degeneration in SOD-deficient models. 相似文献
572.
Toshihiko Hoshide Masato Hirano 《Journal of Materials Engineering and Performance》2010,19(4):562-567
The durability of coated materials with high performance should be adequately evaluated prior to their application. This study
aims at establishing a procedure to estimate the durability of such materials. In this study, a borosilicate glass was coated
with ceramic films by a radio-frequency (RF) magnetron sputtering method, and mechanical properties of materials coated with
single ceramic materials, alumina (Al2O3), silicon carbide (SiC), or titanium nitride (TiN), were investigated. Roughness and hardness were measured as surface characteristics
of coated glass. The strength of coated glass was evaluated under three-point bending mode. It was found that the strength
properties were improved by coating ceramic materials on glass. As for the strength properties, TiN-coated glass was superior
to Al2O3- or SiC-coated glass, although the surface of TiN-coated glass was rougher compared with that of Al2O3- or SiC-coated glass. A new procedure to estimate the strength of coated materials was proposed by incorporating relative
hardness and roughness variations with sputtering time. The strength in experiments was adequately estimated by using the
proposed procedure. 相似文献
573.
Toshihiko Osaki Hiroyuki Masuda Tatsuro Horiuchi Toshiaki Mori 《Catalysis Letters》1995,34(1-2):59-63
The dynamics of produced CO and H2, measured by pulse surface reaction rate analysis (PSRA), revealed that the intermediate hydrocarbon species for the CO2-reforming of CH4 was highly hydrogen-deficient (CH0.75) on supported Co/Al2O3 catalyst. It was also found that the species was more reactive than the less hydrogen-deficient one (CH2.4) on Ni/Al2O3 catalyst. 相似文献
574.
Dietary cyanidin 3-O-β-d-glucoside increases ex vivo oxidation resistance of serum in rats 总被引:1,自引:0,他引:1
The effect of dietary cyanidin 3-O-β-d-glucoside (C3G), a typical anthocyanin pigment, on the generation of thiobarbituric acid reactive substances (TBARS) during serum formation ex vivo and susceptibility of serum to further lipid peroxidation was studied in rats. Rats were fed a diet containing C3G (2 g/kg) for 14 d. Feeding C3G resulted in a significant decrease in generation of TBARS during serum formation. The serum from the C3G-fed group showed a significantly lower susceptibility to further lipid peroxidation provoked by 2,2′-azobis (2-amidinopropane)hydrochloride or Cu2+ than that of the control group. No significant differences were observed in serum phospholipid, triglyceride, esterified cholesterol, and free fatty acid concentrations between the control and the C3G-fed groups. Concentrations of endogenous antioxidants remaining in the serum after blood coagulation were not affected by the C3G feeding. These results demonstrate that feeding C3G increases the ex vivo oxidation resistance of the serum without affecting serum endogeneous antioxidant levels, and reduces the TBARS generated during serum formation without changing the concentrations of serum lipids. 相似文献
575.
Giuseppe Pezzotti Orfeo Sbaizero Valter Sergo Naoki Muraki Ken Maruyama Toshihiko Nishida 《Journal of the American Ceramic Society》1998,81(1):187-192
Fracture of a large-grained alumina polycrystal has been examined in situ by optical microscopy. Concurrently, local bridging stresses, as generated by friction or tension of unbroken ligaments in the wake of the crack path, were measured by piezospectroscopy. Stress measurements were performed both at fixed sites as a function of the external load and at a fixed external load along the crack profile. Frictional stresses were similar/congruent50 MPa, while unbroken ligaments between the crack faces were found to support tensile stresses up to similar/congruent100 MPa. The maximum bridging stress was dictated by the weak (intrinsic) interface bonding of the polycrystal. Average bridging stresses, either theoretically calculated from R -curve data or experimentally measured by piezospectroscopy on frictional/bridging sites, were similar. Such a circumstance enables us to explain the fracture behavior of polycrystalline alumina by considering crack-wake shielding as the main micromechanism contributing to toughening. 相似文献
576.
Arikawa Y Yamanoi K Nagai T Watanabe K Kouno M Sakai K Nakazato T Shimizu T Cadatal MR Estacio ES Sarukura N Nakai M Norimatsu T Azechi H Murata T Fujino S Yoshida H Izumi N Satoh N Kan H 《The Review of scientific instruments》2010,81(10):106105
The characteristics of an APLF80+3Ce scintillator are presented. Its sufficiently fast decay profile, low afterglow, and an improved light output compared to the recently developed APLF80+3Pr, were experimentally demonstrated. This scintillator material holds promise for applications in neutron imaging diagnostics at the energy regions of 0.27 MeV of DD fusion down-scattered neutron peak at the world's largest inertial confinement fusion facilities such as the National Ignition Facility and the Laser Me?gajoule. 相似文献
577.
An estimating procedure for grinding-induced residual stress based on the indentation-fracture (IF) method was proposed by
considering a nonuniform distribution of residual stress in the specimen depth. The proposed procedure was applied to gas
pressure sintered and pressureless sintered silicon nitride ceramics, which were ground under different grinding conditions.
The estimated residual stress was found to be compressive for both materials. The residual stress was dominantly affected
by the grit size of the grinding wheel rather than the cutting depth. Although the dependency of the estimated residual stress
on the grit size was different between the two materials, it was revealed that the estimated residual stress in both materials
qualitatively corresponded with the stress measured by the x-ray diffraction method. In both materials, the bending strength
was reasonably correlated with the estimated residual stress. It was elucidated that the proposed procedure was applicable
to a relative evaluation of the grinding-induced residual stress in machined silicon nitride ceramics. 相似文献
578.
本文介绍的联用分析系统是将超临界流体萃取(SFE)系统与超高效液相色谱(UHPLC)系统联用。使用在线SFE-UHPLC系统,可以完成对胡椒粉中胡椒碱成分的高速萃取和分析。整个分析过程包括萃取时间在内只需要7min。将此方法的萃取回收率与其他萃取方法进行比较,SFE方法得到的回收率与其他方法相当。这种在线SFE-UHPLC方法操作简单,分析速度快。这一方法对于分析固体样品中的化合物组分非常有用,可以有效避免繁琐的样品预处理过程。 相似文献
579.
The value of choice-freedom is a measurement of the variety of choice of an individual and is defined as the maximum amount
a consumer would be willing to pay for the option which is infrequently or not at all used by the consumer. This paper shows
that the value of choice-freedom can be derived from random utility theory and measured by an entropy defined by choice probabilities.
In addition, the interrelationships among choice-freedom, average utility and indirect utility is unified into only one equation,
called the choice equation, and its properties are examined. 相似文献