Receding-horizon predictive control offers a practical approach to complex control problems where robustness and adaptability are required. Important theoretical developments have been reported, leading to many algorithms and acronyms. This paper seeks to provide an encompassing treatment of a broad range of predictive schemes. Some new results on stability are also obtained. 相似文献
Catechin-7-O-β-d-glucopyranoside (CA-G) was previously isolated from red bean (the seed of Phaseolus calcaratus cv. Roxburgh). This study examined the ability of CA-G to scavenge reactive oxygen species generated by cell-free systems
and to protect cells from oxidative stress caused by hydrogen peroxide (H2O2). The mechanism by which CA-G exerts its antioxidant and anti-apoptotic action on H2O2-exposed cells was also investigated. CA-G treatment prevented H2O2-mediated apoptosis and inhibited the formation of single stand breaks in DNA in H2O2-exposed BJAB cells. CA-G suppressed mitochondrial stress and caspase activation caused by H2O2. Mechanistic experiments revealed that the antioxidant mechanism of CA-G on H2O2-mediated oxidative damage was due to the direct scavenging of hydroxyl radicals and/or to the chelation of metal ions that
were used to produce hydroxyl radicals from H2O2 via the Fenton reaction. Collectively, these findings suggest beneficial roles of CA-G or CA-G-rich red bean on the protection
from oxidative damage. 相似文献
As a continuous effort of developing highly enantioselective epoxide hydrolase from marine microorganisms, it was found that Rhodobacterales bacterium HTCC2654 was highly enantioselective toward racemic glycidyl phenyl ether (GPE). An open reading frame (ORF) encoding a putative epoxide hydrolase (EHase) was cloned from the genome of R. bacterium HTCC2654, followed by expression and purification in Escherichia coli. The purified EHase (REH) hydrolyzed (S)-GPE preferentially over (R)-GPE. Enantiopure (R)-GPE from kinetic resolution of 29.2 mM racemic GPE using the purified REH could be obtained with enantiopurity of more than 99.9% enantiomeric excess (ee) and 38.4% yield (theoretical, 50%) within 20 min (enantiomeric ratio (E-value): 38.4). The enantioselective activity of REH toward GPE was also confirmed by the analysis of the vicinal diol, 3-phenoxy-1,2-propanediol. To our knowledge, this study demonstrates the highest enantioselective resolution of racemic GPE using a purified biocatalyst among the known native EHases. 相似文献
ABSTRACT We have used silicon carbide (SiC) thin films as an insulating material of the PZT micro cantilevers for electrical and biological passivation. The use of SiC thin films as a passivation layer of the PZT microcantilevers is also seemingly viable to insure the high mass sensitivity as well as the stable passivation. In this study, we report the effect of SiC passivation layer on the performance of the PZT microcantilevers. The micromachined PZT microcantilevers having a structure of SiNx/Ta/Pt/PZT/Pt were fabricated through MEMS processes. In order to improve the mass sensitivity and the passivation, SiC thin films of the high elasticity material were deposited on the cantilever using plasma enhanced chemical vapor deposition (PECVD) at the temperature of 400°C. Plane-strain modulus of SiC thin film was measured by nanoindentation. We observed that SiC thin films showed higher Young's modulus than Si and SiO2. Before and after the deposition of SiC thin films, the end-tip deflection and the resonant frequency change of microcantilevers were measured by a confocal microscope and an impedance analyzer. It was confirmed that end-tip deflection of microcantilever was reduced by 13~18% through the deposition of SiC thin films, indicating the stress relaxation of the microcantilevers. 相似文献
Formation of diallyl disulfide, identified as a main flavor component of garlic, was gradually decreased by irradiation of 0.05-0.5 kGy, but increased slightly at higher doses of 1.0-3.0 kGy. In garlic stored for 5 months, a dose of 0.1 kGy had little influence on the amount of diallyl disulfide, but higher dose irradiation caused an apparent reduction in the amount of the component. 相似文献
Previously we reported that an epoxide hydrolase (EHase) from Novosphingobium aromaticivorans could preferentially hydrolyze (R)-styrene oxide. In this study, we demonstrate that the purified NEH could be also effective in chiral resolution of racemic epichlorohydrin (ECH). Particularly, the purified NEH showed excellent hydrolyzing activity toward ECH to complete the reaction at a short period of incubation time. Enantiopure (S)-ECH could be obtained with a high enantiopurity of more than 99.99% enantiomeric excess (ee) and yield of 20.7% (theoretical, 50%). The chiral resolution of the purified NEH toward ECH was not susceptible to substrate inhibition by 500 mM racemic ECH. 相似文献
Corn, sorghum, barley, Italian ryegrass (IRG), and alfalfa have long been used in human and/or animal diets. While their nutritional information is widely available, their potentials for anti-oxidation, anti-inflammation, and anti-tumor are barely explored. In the present study, several serial extracts were prepared from 70% methanol extracts of these forage crops and their bioactive potentials were investigated using cell-free and cell-mediated experimental systems. Chloroform extracts in this study generally showed stronger activity to scavenge hydroxyl radicals and superoxide anions than butanol or water extracts. IRG and sorghum chloroform extracts especially almost completely suppressed the lipopolysaccharide-mediated production of nitric oxide, tumor-necrosis factor-α, and interleukin-6. These extracts also inhibited dramatically the viability and DNA synthesis of human skin dermatofibrosarcoma cells without a toxic effect on primary cultured control cells. These beneficial effects appeared to be associated with the amount of flavonoids contained in the extracts.
There are numerous information technology solutions including hardware and software. A company that provides the solution should have knowledge of the customer needs in the purpose of sailing strategy or upgrade policy. The needs are also directly connected to the user satisfaction. However, the users have respective points of view in the needs as well as they may not identify the requirements to improve the solution. SERVQUAL can be an appropriate method to define and measure the customer satisfaction for the information technology solutions. As a case study of the customer satisfaction, the modified SERVQUAL items and scoring method are applied to a cyber-infrastructure system named CyberL ab in Korea. The measurement results of user satisfaction for CyberL ab are provided to confirm that our proposed method performs as we intended. From the results, we can score the satisfaction level of users and identify their needs in the various aspects. The total user satisfaction level for CyberL ab is scored by 88.3. 相似文献
In order to observe the effect of particle shape of poly-dispersed dusts on filter performance, the pressure drop across the
dust cakes of fly ashes from a conventional power plant (PC), fluidized bed combustion (FBC), and paint incinerator (FI) was
measured over a metal filter element in the accurate conditions. A fluidized bed column was used to prepare the dust feed
stream of uniform particle distribution. The fine particles of FI ash have a tendency to be agglomerated at low transport
velocity. The aggregates were broken at high velocity of more than 21 cm/sec. FBC ash composed of jagged type particles and
containing high concentration of unburned-carbon showed higher pressure drop than that of PC ash composed mostly of spherical
particles. FI ash composed of aggregates of very fine carbon particles presented the highest pressure drop among the fly ashes
tested. The shape factors of PC, FBC, and FI ash were estimated as 0.91, 0.76, and 0.65, respectively, by the Ergun equation.
The results implied that the irregular particle tends to form a higher pressure drop and to be more compressible than spherical
one.
This paper is dedicated to Professor Wha Young Lee on the occasion of his retirement from Seoul National University. 相似文献