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941.
Inoue Y. Terada N. Kawarasaki M. Sano K. Ikuta K. 《Selected Areas in Communications, IEEE Journal on》1992,10(9):1474-1488
A granulated broadband network (GBN) is proposed as an intermediate asynchronous transfer mode (ATM) based platform to be part of an evolution scenario toward B-ISDN. The GBN enables various types of services to be provided including 64-kb/s-based services and broadband services. In the GBN, information is transformed into ATM cells at subscriber line terminals or at customer premises and is transferred through ATM networks; consequently, the cost feasibility of a single-channel cell assembly/deassembly device is a significant factor in economically providing ATM-based conventional services and interworking between STM and ATM networks. Various virtual path capacities with a fine degree of granularity can be provided in a mesh structure between transit modes in the GBN. Economic feasibility studies of the GBN, by simulating on certain large-size real networks in the greater Tokyo area, indicate the possibility of a more than 50% cost reduction in transit networks 相似文献
942.
By immunizing ground-state peptides or proteins, we can produce super catalytic antibodies possessing serine protease-like characteristics. The unique feature of super catalytic antibodies is their ability to decompose a target molecule that is being killed. The authors have succeeded in preparing super catalytic antibodies that destroy (i) the HIV-1 envelope protein gp41, (ii) chemokine receptor CCR5 peptide, and (iii) Helicobacter pylori urease, etc. Some of them can degrade antigens at high catalytic reaction rates. Regarding their Km and kcat, super catalytic antibodies show intermediary values between that of enzymes (high Km and kcat) and that of antibodies (low Km and kcat [=0]). The catalytic function of an antibody mostly resides in its light chain. From mouse Vkappa germline analysis, it became clear that super catalytic antibodies are generated from some discrete germlines such as bb1, cr1, cs1, bl1, bj2 and bd2. In these Vkappa germlines, at least one catalytic triad composed of three amino acid residues, namely, Asp1, Ser27a and His93, is encoded. Namely, the antibody light chains (super catalytic antibodies) generated from the germlines are inherently able to enzymatically decompose antigens. Thus, such antibody light chains can be referred to as antigenase (antigen-decomposing enzyme) and may have arisen during the evolution of antibodies to acquire a higher ability than that of enzymes for developing a sophisticated self-defense system for survival. 相似文献
943.
Unknown genetic regulation mechanisms are expected to be discovered by information technology using large amount of biological data especially for gene expression data. In this study, we propose a novel inferring method for genetic interactions that combines our original preprocessing method and the Boolean algorithm. First, the performance of our method was evaluated using artificial data. The results showed that our method was able to infer genetic interactions with high specificity (specificity=0.629). Then, using our method, the genetic interaction was inferred from the experimental time course data collected using microarray on 69 genes of cell cycle for Saccharomyces cerevisiae. Our method estimated about 80% of all genetic interactions in Kyoto Encyclopedia Genes and Genomes (KEGG) for these genes. Furthermore, our method was able to infer several other genetic interactions that are not included in KEGG but whose existence is supported by other biological reports. 相似文献
944.
Shimoda K Kubota N Sano T Hirakawa H Hirata T 《Journal of Bioscience and Bioengineering》2004,98(2):67-70
A novel 55-kDa hydroxylase was isolated from cultured cells of Catharanthus roseus by a three-step procedure: anion exchange chromatography, affinity chromatography and hydroxylapatite adsorption chromatography. The enzyme specifically catalyzed the hydroxylation of 2-hydroxybenzoic acid to give 2,5-dihydroxybenzoic acid. The enzyme activity was optimal at pH 7.8 and was completely inhibited by divalent cations, such as Cu(2+) and Hg(2+). The enzyme showed sequence similarity to certain plant flavonoid 3'-hydroxylases. 相似文献
945.
Sugiyama T Shinozuka K Sano A Yamada S Endoh K Yamada K Umegaki K 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(6):295-301
In previous papers, we showed that Ginkgo biloba extract (GBE) induced hepatic cytochrome P450 (CYP) activity, in particular pentoxyresorufin O-dealkylase (PROD; corresponding to CYP2B type) in rats, and that GBE influenced the efficacy of co-administered drugs. In this study, to clarify the nature of the induction, we examined the effects of GBE samples from different sources and some major constituents of GBE on rat hepatic CYP in vitro and in vivo. In the study in vitro, eight GBE samples dose-dependently inhibited PROD activity in microsomes prepared from GBE-treated rats, and the inhibitory ratio correlated well with the content of proanthocyanidin in the GBE samples. Moreover, among six GBE constituents examined, proanthocyanidin markedly inhibited the PROD activity. However, administration of two GBE extracts with different proanthocyanidin contents to rats induced hepatic CYP activity, including PROD, to similar extents, and proanthocyanidin alone did not induce PROD activity. Furthermore, GBE samples extracted with both acetone-water and ethanol-water showed similar induction of CYPs in rats in vivo. These results suggest that most GBE samples available in Japan induce CYPs in rats regardless of the preparation method of the GBE, and that proanthocyanidin is not responsible for the induction. Further studies will be necessary to identify the constituent(s) of GBE involved in the induction of CYPs in vivo. 相似文献
946.
In this study, Norovirus (NV) capsid gene was detected from patients of gastroenteritis, domestic sewage, treated wastewater, river water and cultivated oysters in geographically close areas where all of samples were collected. In order to improve recovery efficiency of NVs from oysters, a new method using a spallation apparatus was developed. As a result, 18 of 30 oysters (60%) were positive for NV gene, while 7 of 30 (23%) oysters from the same sampling point were positive with the conventional ultracentrifugal method between November 2003 and February 2004. These results indicate that our new method exhibits the higher efficiency of recovering NVs than the conventional ultracentrifugal method. Six of 8 samples (75%) of river water were positive for NV gene between November 2003 and February 2004. Furthermore, 8 of 9 samples (89%) of treated wastewater and all 9 samples of sewage were positive for NV gene in the same period. These results indicated that treated wastewater would be one of the main sources for NV pollution in this area. The phylogenetic analysis in isolated NV capsid genes was conducted, in which high identities of gene sequences between NVs from patients, domestic sewage, river water and cultivated oysters were observed. These results implied that there would be a geographically associated circulation of NVs between human and cultivated oysters via water environment. It would be important to quantitatively analyze the moving pathway of NVs, which directly link to the development of a new scheme for preventing water environment and cultivated oysters from NV contamination. 相似文献
947.
Shigeru Ueda Kazuki Morita Nobuo Sano 《Metallurgical and Materials Transactions B》1997,28(6):1151-1155
The thermodynamics of phosphorus in molten Si-Fe and Si-Mn alloys has been investigated at 1723 K by equilibrating the alloys
in a controlled phosphorus partial pressure. The activity coefficient of phosphorus in each alloy shows a maximum value at
a certain composition due to a strong interaction between silicon and iron and between silicon and manganese. Interaction
coefficients between phosphorus and iron in molten silicon were found to be ε
P
Fe
=7.43 and ρ
P
Fe
=−16.4 (0≦X
Fe≦0.65), and those between phosphorus and manganese were ε
P
Mn
=12.0 and ρ
P
Mn
=−22.2 (0≦X
Mn≦0.5). Further discussion has revealed that the Si-Fe-P and Si-Mn-P systems approximately conform to a regular solution within
the composition ranges investigated in the present work. 相似文献
948.
Koichi Iuchi Kazuki Morita Nobuo Sano 《Metallurgical and Materials Transactions B》1998,29(6):1235-1240
The rate of nitrogen dissolution in CaO-Al2O3-SiO2 and CaO-Al2O3-TiO
x
melts was measured by 14N–15N isotope exchange reaction. The rate constant for the CaO-Al2O3-SiO2 melts at the ratio of mass pct CaO/mass pct Al2O3 = 1 increases as SiO2 content increases, whereas the rate constant for the same melts at the ratio of mass pct CaO/mass pct SiO2 = 1 increases as Al2O3 content increases. The rate constant for the CaO-Al2O3-TiO
x
melts at the ratio of mass pct CaO/mass pct Al2O3 = 1 decreases as the TiO
x
content increases. The activation energies of nitrogen dissolution in CaO-Al2O3-SiO2 melts are about 1.5 to 3 times larger than that of molten pure iron. Moreover, the rate constant of nitrogen dissolution
is independent of the ratio of Ti3+/Ti4+. 相似文献
949.
In a case of neurosarcoidosis with bilateral facial nerve palsy and hydrocephalus, contrast-enhanced magnetic resonance imaging (MRI) study and angiotensin converting enzyme (ACE) activities in cerebrospinal fluid (CSF) were valuable for the diagnosis and the follow up. Facial nerve lesions were demonstrated on gadolinium-DTPA enhanced MRI. The disappearance of enhancement was concomitant with the amelioration of facial nerve palsy after corticosteroid therapy. 相似文献
950.
A novel 2:1 selector circuit is described. To achieve high-speed operation, a parallel feedback circuit and inductor peaking were added to a conventional selector circuit. Furthermore, wide bandwidth buffers are carefully designed to cover the operation frequency of this selector circuit. The selector IC, fabricated with 0.1 μm class GaAs MESFETs, operated at up to 44 Gbit/s 相似文献