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101.
Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood–brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures.  相似文献   
102.
Various terpene alcohols were prepared from isoprene oligomers via two steps: epoxidation with peracetic acid and isomerisation with aluminium triisopropoxide. For example, 2-methylene-6-methyl-7-octene-1-o1 was prepared from 2,6-dimethyl-1,7-octadiene. From 2,6-dimethyl-2,7-octadiene, 3,3,6-trimethyl-1,5-heptadiene, 2,7-dimethyl-2,6-octadiene, 2,6-dimethyl-1,3,6-octatriene, 1-methyl-4-isopropenyl-1-cyclohexene, and 1,5-dimethyl-1,5-cyclooctadiene, the corresponding alcohols were obtained, respectively.  相似文献   
103.
A three-dimensional simulation model for colloidal dispersion system with an adsorptive surface under a specified bulk concentration was developed basing on the Brownian dynamics technique, and the adsorption process of electrostatically stabilized colloidal particles with radius of 50 nm onto a planar surface with counter charge was simulated. The particle-particle and particle-surface interactions were modeled on the DLVO theory. The adsorbed particles are found to form hexagonally ordered array, only if the surface coverage is above a certain threshold, which varies depending on the ionic strength or the interaction potentials. Through the analysis of the ordered structure, we found that the determinant factor for the order formation is “one-directional average force” acting between adsorbed particles, which exhibits a common value regardless of the ionic strength. Also, looking at the last process for establishing the order, we developed a model that can predict the potential barrier for the order formation. Further, the order formation was proven to be a stochastic phenomenon, and a model to describe the probability against time was developed and its quantitative validity was demonstrated.  相似文献   
104.
Y. Inoue  Y. Watanabe 《Catalysis Today》1993,16(3-4):487-494
A poled ferroelectric LiNbO3 single crystal with high spontaneous polarization was employed as a catalyst support, and the static and dynamic effects of the polar substrate surfaces on the adsorptive and catalytic properties of thin film catalysts deposited were shown. For the static effect, it was demonstrated that the surface conductivity of copper and metal-free phthalocyanine films increased by the adsorption of NO gas, to a larger extent, when the substrate was the negative polar surface, compared to the positive one. The role of the polar substrates is explained In terms of a band bending model. For the dynamic effect, the Rayleigh surface acoustic wave generated on the LiNbO3 substrate was shown to enhance the catalytic activity for ethanol oxidation on Cu and Ag thin film catalysts deposited on the propagation path. It is proposed that the catalyst activation is mainly due to an electric Held produced. The use of poled LiNbO3 is suggested to be effective for the development of a device-type catalyst with activity controllable functions.  相似文献   
105.
Mechanical Properties of Alumina/Silicon Carbide Whisker Composites   总被引:1,自引:0,他引:1  
The improvement of mechanical properties of Al2O3/SiC whisker composites has been studied with emphasis on the effects of the whisker content and of the hot-pressing temperature. Mechanical properties such as fracture toughness and fracture strength increased with increasing whisker content up to 40 wt%. In the case of the high SiC whisker content of 40 wt%, fracture toughness of the sample hot-pressed at 1900° decreased significantly, in spite of densification, compared with one hot-pressed at 1850°. Fracture toughness strongly depended on the microstructure, especially the distribution of SiC whiskers rather than the grain size of the Al2O3 matrix.  相似文献   
106.
Comparing the thermal properties of TiO2 encapsulating polystyrene and poly(methyl methacrylate) with those of TiO2 dispersion polymers it was found that the encapsulating polymers have two thermal relaxation regions. The activation energy of those thermal relaxation regions was determined using the Wunderlich method and it was found that the values are similar to the activation energy for the dynamic dispersion. It is suggested that the low-temperature thermal relaxation is caused by the local change of conformation of molecular chains, while the high-temperature thermal relaxation is similar to that of the normal glass transition temperature including the interaction with TiO2. In addition, the thermal behaviour near the degradation point in different atmospheres indicates that the encapsulating polymer has a specific structure for adsorbing a large amount of oxygen.  相似文献   
107.
The structure of silicon carbide–silicon nitride (SiC–Si3N4) composite particles synthesized using a CO2 laser was studied by magic angle spinning nuclear magnetic resonance (MAS-NMR) and electron spin resonance (ESR). The structure around Si atoms changed by introducing N. C atoms around Si were substituted by N atoms, and N-rich configurations around Si atoms increased stepwise as the N content increased. The low N content composite particles consisted of mainly SiC phase containing dissolved N. N atoms were partly present in β-SiC microcrystal and partly in the grain boundary layer in the particle. N atoms were tetrahedrally surrounded by four Si atoms in β-SiC microcrystal and were trivalent state bonded to three Si atoms in the grain boundary layer. The high N content particles consisted of SiC, Si3N4, and amorphous phases, whose amount depended on N content.  相似文献   
108.
Monofluoro esters were prepared by the reaction of hydroxy esters with N,N-diethyl-1,1,2,3,3,3-hexafluoro propylamine (PPDA). Saponification of these monofluoroesters with enzyme (lipase MY) was attempted to give their corresponding monofluorocarboxylic acids in moderate yields.  相似文献   
109.
Thermal cracking of tar-sand bitumens has been carried out using a two-stage pyrolysis reactor with temperature zones of 440°C and 750–800°C, respectively. Feedstocks were pyrolysed in the first stage into cracked oils, which were carried to the second stage for subsequent pyrolysis. Only 12–14 wt% of ethylene was obtained from tar-sand bitumens at the residence time of 1.2 s in the second stage, although 27 and 16 wt% were obtained from Taching and Iranian heavy vacuum residues, respectively. The tar-sand bitumens contain shorter paraffinic straight-chains and have more branched molecules than the vacuum residues of petroleum. A straight-chain paraffin index is proposed, with which a good correlation was obtained between ethylene yield and the fraction of straight-chain paraffin carbons in the heavy oil.  相似文献   
110.
Dynamic mechanical properties and adhesive strengths of power feed copolymer and random copolymer synthesized using styrene or methyl methacrylate and n-butyl acrylate were investigated. Although the two systems were synthesized from the same raw materials, power feed copolymer had a very broad transition compared with random copolymer. This fact was explained by the fact that the system synthesized through power feed method was an alloy of copolymers which are a continuous series from monomer A rich copolymers to monomer B rich copolymers. The dynamic mechanical behavior of film cast from solution was almost the same as that of emulsion film, which indicated more extensive application of power feed copolymer. In the P(nBA/St) system, power feed copolymer maintained its adhesive strengths over a wide temperature range compared with random copolymer. The absolute value, however, was not so high. This was due to the low cohesive strengths of the films.  相似文献   
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