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151.
Hormone-sensitive lipase (HSL) catalyzes the rate-limiting step in adipocyte lipolysis. We have studied the effect of glucose and long chain fatty acids on the HSL mRNA content of 3T3-F442A adipocytes. Exposure of the cells for 32 h to a medium without glucose led to a decrease by a factor of 2.5-3 in the HSL mRNA without a change in C/EBP alpha mRNA or triglyceride content of the adipocytes. The reduction in HSL mRNA level was accompanied by a decrease in HSL total activity. The effect of glucose exposure was observed after 24 h of exposure and was reversible. Treatment of the adipocytes with oleate did not affect HSL expression. These data show that glucose modulates HSL gene expression and hence could participate in the regulation of adipose tissue lipolysis.  相似文献   
152.
Gas analysis provides a promising means for a diagnosis of gas-insulated equipment. Although many studies have been concentrated on SF6 gas decomposition, they were mostly related to the faults in GIS systems and not directly applicable to gas-insulated transformers, which have much more complicated material structure. An experimental survey on decomposition by-products at various abnormal conditions was carried out by use of simulation models to develop a diagnostic method for gas-insulated transformers based on gas and ion chromatograph analyses. Major components characteristic in each abnormality, such as SO2 on metal overheat, SO2F 2 on partial discharges, etc. were identified by the experiments  相似文献   
153.
The Tokyo Electric Power Co. Inc. (TEPCO) and Toshiba developed an energy management system that was put into operation in December 1988. The authors review the background of developing the new system and the concept underlying the development, with the aim of improving reliability and enhancing capability. They describe the system configuration, configuration control of the distributed subsystems, and the application software. To enhance system function, two subsystems (one composed of two computers and another composed of a single computer) were planned to be installed in February 1990. One unit will analyze and access the voltage stability of the power system on a real-time basis. The other will perform the monitoring and analysis of demand characteristics by collecting information on active as well as reactive power consumption of typical users  相似文献   
154.
The results are given of calculations of the pressure to compress plastically, ideal material between perfectly rough parallel plates of variously unequal widths which do not overhang the material and in which the die width exceeds the material thickness. The rate of approach of the dies is also stated for certain die parameters. A particular solution is also given for the case when there is less than shearing friction between the material and the plates.  相似文献   
155.
Ubiquitination and deubiquitination are two popular ways for the post-translational modification of proteins. These two modifications affect intracellular localization, stability, and function of target proteins. The process of deubiquitination is involved in histone modification, cell cycle regulation, cell differentiation, apoptosis, endocytosis, autophagy, and DNA repair after damage. Moreover, it is involved in the processes of carcinogenesis and cancer development. In this review, we discuss these issues in understanding deubiquitinating enzyme (DUB) function in head and neck squamous cell carcinoma (HNSCC), and their potential therapeutic strategies for HNSCC patients are also discussed.  相似文献   
156.
Aqueous solutions of isovaline and its precursor molecule, 5-ethyl-5-methylhydantoin, were irradiated with ultraviolet and γ-ray photons, to evaluate their structural stability against space radiation. The degree of photolysis was measured and irradiation products were identified using chiral, reversed-phase and ion-exchange high-performance liquid chromatography. The experimental results show that the degree of photolysis of 5-ethyl-5-methylhydantoin is more significant than that of isovaline under ultraviolet light irradiation, while the results under γ-ray irradiation are the opposite. As the products of isovaline photolysis, aspartic acid, serine, glutamic acid and alanine were dominantly detected.  相似文献   
157.
Effects of epoxidized 1,2- or 1,4-polybutadienes on the zinc stearate/calcium stearate synergetic soap-induced thermal stabilization of poly(vinyl chloride) (PVC) were investigated by colorimetry. The remarkable stabilization effects of epoxidized polybutadienes could not be observed on the PVC films without synergetic soaps, while the stabilization of PVC was markedly enhanced by combined use of epoxidized polybutadienes with synergetic soaps. Excessive coloration of cool color-producing zinc chloride-polyene complexes that were the source of abrupt discoloration of stabilized PVC was retarded by using epoxidized polybutadienes together with synergetic soap. The synergism of epoxidized polybutadienes was enhanced with increasing epoxy contents. Moreover, the effect is also clearly dependent on degree of dispersion of epoxidized polybutadienes in PVC. Further colorimetries, infrared (IR), and X-ray photoelectron spectroscopies on the various PVC-containing epoxidized polybutadienes and zinc chloride indicated that the epoxy groups capture the zinc chloride. The synergistic effect between epoxidized polybutadienes and metal soap was ascribed to epoxidized polybutadienes serving as acceptors for the excessive cool color-producing zinc chloride produced by zinc stearate to retard the abrupt discoloration of stabilized PVC. The plate-out phenomenon appeared during the molding process of PVC-containing epoxy compounds was considerably retarded by epoxidized polybutadienes which modified polyols. The polyol-modifying epoxidized polybutadienes also exhibited a marked effect on PVC stabilization with metal soap.  相似文献   
158.
Photocatalytic water splitting into H2 and O2 over various tantalates was reviewed and factors affecting photocatalytic activities of tantalates were discussed from a viewpoint of the crystal structure and the energy structure. Many tantalates, K3Ta3Si2O13, alkali and alkaline earth tantalates, were highly active photocatalysts for water splitting. The high activities were mainly due to the high conduction band level consisting of Ta5d orbitals. NiO-loaded NaTaO3 with the distorted perovskite structure showed the highest activity among tantalates. Moreover, the activity of the NiO/NaTaO3 photocatalyst was remarkably improved by doping of lanthanoids. The apparent quantum yield of NiO/NaTaO3 doped with lanthanum was ca. 50% at 270 nm.  相似文献   
159.
160.
The pulse height distribution in 3He proportional counters has been investigated to accurately quantify the response function to be used in fast neutron spectroscopy. The measurements were performed as a function of the operating voltage, the counting gas mixture, and the incident neutron energy. The special emphasis of this study has been put on the nonlinearity of the pulse height of a recoil helium induced by the 3He(n,n)3He reaction. A distinct deviation of 14% at maximum to lower energies was found in the position of the recoil edge with the energy axis calibrated by the full energy peaks of the 3He(n,p)T reaction produced with neutrons of thermal energy and 2.413 MeV. It was confirmed that the nonlinear effects, such as an initial recombination and a space-charge effect, take place more significantly in the energy loss process of a recoil helium because of its higher linear energy transfer (LET) in the filling gas compared to that of a proton and triton pair emitted from the 3 He(n,p)T reaction. The deviation becomes larger with an increase of the average LET in the gas mixture. The experimental results suggested that the nonlinear effect caused by a higher LET recoil helium is inevitable for the filling gas, even if the operating voltage is changed to an acceptable range  相似文献   
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