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61.
Shuzo Morita Tsuneo Katsuyama Kazuhiko Ito Hichiro Hayami 《International Journal of Communication Systems》1989,2(1):3-11
This paper proposes a new integrated switching system, ‘elastic basket switching’, for broadband and multimedia communications, including voice and high-speed data. In elastic basket switching (EBS), it is possible flexibly and efficiently to handle multimedia information by adaptively assigning communication resources according to communication requests and bandwidth of switched information. For continuous information, such as voice, EBS functions just as a circuit switching system, and for burst data it achieves high-efficiency bandwidth usage equivalent to a packet switching system by demand-assign type time-slot assignment. The detail of EBS and its application to a departmental system-orientated PBX are described. The traffic handling capability and details of the hardware structure are presented. The experimental system, including use of LSIs in the main parts of EBS is also described. 相似文献
62.
63.
We developed a micro total analysis system (mu-TAS) incorporating chemiluminescence detection, in which the chemiluminescence reaction of isoluminol isothiocyanato (ILITC) (as a chemiluminescence reagent for labeling)-microperoxidase (as a catalyst)-hydrogen peroxide (as an oxidant) was adopted. The analysis system performed the following three processes on a microchip: immune reaction for high selectivity, electrophoresis for formation and transportation of the sample plug, and chemiluminescence detection for high sensitivity. The three processes were compactly integrated onto the microchip to give the mu-TAS. The microchip contained two microchannels that crossed at an intersection, while the ends of the microchannels accessed four reservoirs. As the first process, the immune reaction was performed using an antibody-immobilized glass bead. The glass bead was placed in one of the reservoirs along with antigen (analyte) and a known amount of ILITC-labeled antigen to set up a competitive immune reaction. For electrophoresis, as the second process, the reactant after the immune reaction was fed electrophoretically into the intersection resulting in a sample plug. The sample plug was then moved into another reservoir containing hydrogen peroxide solution. At this point, chemiluminescence detection was performed as the third process: the labeled antigen mixed with the hydrogen peroxide and the catalyst included in the migration buffer to produce chemiluminescence. Chemiluminescence was detected by a photomultiplier tube located under the reservoir. The mu-TAS described here was capable of determining, with high selectivity and sensitivity, human serum albumin or immunosuppressive acidic protein as a cancer marker in human serum. 相似文献
64.
Kinetic study of thermostable L-threonine dehydrogenase from an archaeon Pyrococcus horikoshii 总被引:1,自引:0,他引:1
In the genome data base of the hyperthermophilic archaeon Pyrococcus horikoshii, an open reading frame with sequence homology to a gene encoding alcohol dehydrogenase was found. It was demonstrated that the encoded enzyme was a thermostable L-threonine dehydrogenase which can oxidize the hydroxy alkyl residue of L-threonine associated with the reduction of NAD+ or NADP+. This enzyme is a member of the zinc-containing L-threonine dehydrogenase family. One enzyme molecule contained one zinc atom, and this metal was considered to contribute to the hyperthermostablility of the enzyme. The reaction of the enzyme proceeded via a sequential mechanism. The Michaelis constants (Km) for L-threonine and NAD+ were 0.013 and 0.010 mM, respectively, and the maximum reaction rate (Vmax) was 1.75 mmol NADH formed/min/mg-protein at 65 degrees C. The Km values for both L-threonine and NADP+ were larger than those for L-threonine and NAD+ with a similar Vmax value. These results indicate that the enzyme has lower affinity to NADP+ than to NAD+, and the binding affinity for L-threonine depends on the coenzymes. 相似文献
65.
A heuristic algorithm for cell formation problems with consideration of multiple production factors 总被引:1,自引:1,他引:0
ChenGuang Liu Yong Yin Kazuhiko Yasuda Jie Lian 《The International Journal of Advanced Manufacturing Technology》2010,46(9-12):1201-1213
For the design of manufacturing cells, numerous mathematical models and various algorithms have been extensively investigated in the literature. However, most of the proposed models and algorithms have more or fewer drawbacks on the issues with real-life situations. In this paper, we propose a mathematical model that incorporates multiple key real-life production factors simultaneously, namely, production volume, batch size, alternative process routings and perfect coefficient of each routing, cell size, unit cost of intercell/intracell movements, and path coefficient of material flows. Then, to solve this NP-hard model, we develop a heuristic algorithm with three stages: (1) form the temporary machine group plan according to the alternative process routings of each part, (2) select the appropriate process routing of each part with respect to the over-all material movement cost, and (3) configure the regular manufacturing cells based on the appropriate process routing. A simple numerical example and an industrial case are used to test the computational performance of the proposed algorithm. The test results imply that it is useful for manufacturing cell design in both quality and speed. 相似文献
66.
考虑土、上部结构和桥台相互作用的桥台抗震性能研究 总被引:3,自引:1,他引:2
在以往的桥梁设计中并不考虑基础提离和地基土屈服等土与桥台相互作用对桥台地震反应的影响。因此,为了研究桥台在地震中的抗震性能,采用Newmark时程分析方法对考虑土、上部结构和桥台相互作用的由扩展基础支撑的桥台进行分析。采用离散的质点–弹簧模型对土、上部结构和桥台系统进行建模。利用非线性模型,模拟上部结构和桥台的碰撞反应、桥台背部填土及地基土的弹塑性反应,并采用Winkler地基梁模型模拟地基土与桥台基础的相互作用。分析结果表明,桥台基础的提离作用可以减弱桥梁上部结构及桥台在强烈地震中的反应,减小桥台墙身底部在强震作用下发生的塑性变形,起到一定的减震隔震效果。同时,桥台底部土的屈服减小了传递到桥台底部塑性铰处的弯矩,进一步增强了桥台基础提离的效果。然而,由地基土屈服引起的永久性沉降也造成桥台基础的倾斜。因此,在桥梁的抗震设计中,必须考虑桥台基础的提离和地基土的屈服等土与结构相互作用对桥台抗震性能的影响。 相似文献
67.
Yasutaka Nagai Kazuhiko Dohmae Kentaro Teramura Tsunehiro Tanaka Gemma Guilera Kazuo Kato Masaharu Nomura Hirofumi Shinjoh Shinichi Matsumoto 《Catalysis Today》2009,145(3-4):279
Two main pivotal subjects of research in automotive catalysts were studied by modern X-ray absorption analysis techniques. One is oxygen storage/release behaviour, and the other is sintering inhibition of Pt particles. First, three types of CeO2–ZrO2 (Ce:Zr = 1:1 molar ratio) compounds with different oxygen storage/release capacities and different structural properties were prepared, and the valence change of Ce as a function of temperature during oxygen release/storage processes was investigated. The reduction of surface Ce mainly occurred in the range 100–170 °C, and the reduction of bulk Ce progressed at high temperatures of 170 °C and above. The Ce reduction behaviour depended not only on the homogeneity of the Ce and Zr for bulk reduction at high temperatures but also on the particle size of the CeO2–ZrO2 samples for surface reduction at low temperatures. Secondly, sintering inhibition of Pt in Pt/Al2O3, Pt/MgO and Pt/ceria-based catalysts after 800 °C ageing in air was studied. We found that the Pt–O–M (M = Mg, Ce) bond acted as an anchor and inhibited the sintering of Pt particles on MgO or ceria-based oxide. Especially, it was noteworthy that the Pt–O–Ce4+ bond on the ceria-based support breaks easily through the reduction of Ce (Ce4+ → Ce3+) during the usual stoichiometric and reducing conditions. 相似文献
68.
The configuration isomers alpha,alpha-, alpha,beta-, and beta,beta-trehalose are distinguishable by a relative ion abundance analysis using collision-induced dissociation MS/MS measurements in electrospray ionization quadrupole-time-of-flight mass spectrometry. The relative abundance of the Y-type fragment ion of alpha,alpha-trehalose is the highest and that of beta,beta-trehalose is the lowest, indicating that alpha-glycosyl bonds cleave more easily than beta-glycosyl bonds. The relative ion abundance depends on both the alpha- and beta-glycosyl linkage type and the number of alpha-glycosyl bonds. The reaction path of glycosyl bond cleavage is calculated computationally using the molecular orbital method in the form of Hartree-Fock theory in conjunction with the 6-31G(d) basis set. The results are consistent with the experimental data. Isotope effects on the fragmentation of the glycosyl bonds are detected in the experiments of the H2O/D2O solvent systems. Furthermore, the isotope effect regarding beta,beta-trehalose is larger than those of alpha,alpha- and alpha,beta-trehalose, indicating that the isotope effect on the beta-glycosyl bond cleavage is larger than that on the alpha-glycosyl bond cleavage. The thermal energy increase in trehalose-d8 molecules over the corresponding trehalose molecules is calculated from the vibrational modes. 相似文献
69.
Mastitis is the most frequent and prevalent production disease in dairy herds in developed countries. Based on a milk somatic cell count (SCC) of either >300,000 or <200,000 cells/ml in this study, we defined the quarter as either inflamed or uninflamed, respectively. The electrical conductivity (EC) of milk was used as an indicator of udder epithelial cell damage. We determined the amount of H2O2 produced by utilizing a small molecular weight compound in milk, and examined the characteristics of H2O2 production and EC in milk from inflamed and uninflamed quarters. In cows with milk of delivery grade (control population), H2O2 production and EC were 3.6+/-1.3 nmol/ml and 5.4+/-0.4 mS/cm (mean+/-sd), respectively. In 37 inflamed quarter milk samples, the production of H2O2 was 1.9+/-1.0 nmol/ml and was significantly smaller than that in the control population (P<0.01). Production of H2O2 was moderately but significantly correlated with EC (r<-0.71). In 20 cows with inflamed quarters, the production of H2O2 in milk from inflamed quarters was significantly smaller than that in milk from uninflamed quarters (P<0.01). In 18 out of 20 cows, milk from inflamed quarters showed the smallest H2O2 production among all tested quarters in each cow. We conclude that inflammation caused a decrease in H2O2 production in milk. In this study, we present parameters for evaluating the lactoperoxidase/H2O2/thiocyanate antibacterial defence system in bovine milk. 相似文献
70.
The discovery of Lgr5+ intestinal stem cells (ISCs) triggered a breakthrough in the field of ISC research. Lgr5+ ISCs maintain the homeostasis of the intestinal epithelium in the steady state, while these cells are susceptible to epithelial damage induced by chemicals, pathogens, or irradiation. During the regeneration process of the intestinal epithelium, more quiescent +4 stem cells and short-lived transit-amplifying (TA) progenitor cells residing above Lgr5+ ISCs undergo dedifferentiation and act as stem-like cells. In addition, several recent reports have shown that a subset of terminally differentiated cells, including Paneth cells, tuft cells, or enteroendocrine cells, may also have some degree of plasticity in specific situations. The function of ISCs is maintained by the neighboring stem cell niches, which strictly regulate the key signal pathways in ISCs. In addition, various inflammatory cytokines play critical roles in intestinal regeneration and stem cell functions following epithelial injury. Here, we summarize the current understanding of ISCs and their niches, review recent findings regarding cellular plasticity and its regulatory mechanism, and discuss how inflammatory cytokines contribute to epithelial regeneration. 相似文献