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排序方式: 共有160条查询结果,搜索用时 250 毫秒
1.
The educational system has gradually shifted from a face-to-face to an e-learning system, which has become prevalent in advanced countries with the advance of information technology, and connection of global networks. Accordingly, a growing demand is emerging for more reliable individual certification with technical precision in order to measure and record learning achievements and credentials of participants. The present system has a limit in terms of registration capacity, therefore, its accuracy has often been questioned. Against this background, an individual certification system is proposed particularly for access control in e-learning. Under our proposed system, a compact optical correlator for facial recognition is employed. This correlator was previously tested for of biometrics authentication accuracy and proved highly reliable, having recorded remarkably low error rates (below 1%). The recorded error rate is sufficiently robust that the system itself can be regarded as a valid and practical viable attestation system. 相似文献
2.
Watanabe G Umetsu K Yuasa I Sato M Sakabe M Naito E Yamanouchi H Suzuki T 《Electrophoresis》2001,22(3):418-420
We present a simple and rapid polymerase chain reaction (PCR)-based technique, termed consumed allele-specific primer analysis (CASPA), as a new strategy for single nucleotide polymorphism (SNP) analysis. The method involves the use of labeled allele-specific primers, differing in length, with several noncomplementary nucleotides added in the 5'-terminal region. After PCR amplification, the amounts of the remaining primers not incorporated into the PCR products are determined. Thus, nucleotide substitutions are identified by measuring the consumption of primers. In this study, the CASPA method was successfully applied to ABO genotyping. In the present method, the allele-specific primer only anneals with the target polymorphic site on the DNA, so it is not necessary to analyze the PCR products. Therefore, this method is only little affected by modification of the PCR products. The CASPA method is expected to be a useful tool for typing of SNPs. 相似文献
3.
Dehydration of zinc biladienone was catalyzed by zinc acetate, while the reverse reaction was catalyzed by triethylamine. The transformation can be performed thermally without catalyst, and the ratio of the hydrated form to the dehydrated form depended on the solvents: the dehydrated form is favored in CHCl3 and CH2Cl2, while the hydrated form is favored in hexane, pyridine, and DMF. Kinetic studies on the thermal transformation of zinc biladienone from its hydrated blue form to the dehydrated yellow-brown form were performed in toluene and THF. The rate law was half order with respect to the zinc biladienone concentration in toluene, while first order in THF, leading to a slow transformation in concentrated solution in toluene. 相似文献
4.
Umetsu K Tanaka M Yuasa I Adachi N Miyoshi A Kashimura S Park KS Wei YH Watanabe G Osawa M 《Electrophoresis》2005,26(1):91-98
We present a reliable, rapid, and economical multiplex amplified product-length polymorphism (APLP) method for analyzing the haplogroup-diagnostic mitochondrial single-nucleotide polymorphisms (mtSNPs) in East Asian populations. By examining only 36 haplogroup-specific mtSNPs in the coding region by using four 9-multiplex polymerase chain reaction (PCR) and subsequent electrophoresis, we could safely assign 1815 individuals from 8 populations of Japanese, Korean, Chinese, and Germans to 45 relevant haplogroups. This multiplex APLP analysis of coding-region mtSNPs for haplogrouping is especially useful not only for molecular phylogenetic studies but also for large-scale association studies due to its rapid and economical nature. This is the first panel of mtSNPs in the coding region to be used for haplogrouping of East Asian populations. 相似文献
5.
Human alpha 2HS-glycoprotein (AHSG) phenotypes were studied by isoelectric focusing of native and desialyzed samples followed by passive immunoblotting. At present a total of 15 different alleles could be distinguished. The usefulness of AHSG polymorphism in the field of forensic hemogenetics was demonstrated by markedly high variability at AHSG locus, reliability of phenotyping results and stability in blood stains. 相似文献
6.
Suyama Kyozo Fukazawa Yoshitaka Umetsu Yoshiyaki 《Applied biochemistry and biotechnology》1994,(1):871-879
The egg shell membrane (ESM) is an intricate lattice network of stable and water-insoluble fibers with high surface area.
ESM accumulates and eliminates various heavy metal ions from dilute aqueous solution with high affinity and in short contact
time, depending on pH and characteristics of the individual ion. Under certain conditions, the level of precious ions, Au,
Pt, and Pd accumulation approaches 55, 25, and 22% of dry wt of ESM, respectively. Also uranium uptake 30% of that of ESM.
Experiments suggested that ESM is promising to use for the purpose of removal/recovery of metals and water pollution control. 相似文献
7.
In the course of a population study of alpha 1-antitrypsin polymorphism by separator isoelectric focusing, a variant phenotype having a somewhat narrower spacing than PI M1M3 was observed in a Japanese blood donor. Family studies by hybrid isoelectric focusing in a carrier ampholyte-supplemented immobilized pH gradient from 4.35-4.65 revealed that the products of the responsible gene, PI*Mtoyoura, were extremely close but slightly cathodal to those of PI*M1. The difference in isoelectric point between them corresponded to the resolving limit of isoelectric focusing. For this reason, although the propositus' father was deduced to have the genotype PI*M1/PI*Mtoyoura, the products of these two genes failed to form a double band pattern. Thus, the gene frequency for PI*Mtoyoura was unknown. These findings, however, indicate that a further microheterogeneity in the PI M subtype exists at least in the Japanese. 相似文献
8.
Ishizaka T Miyanaga Y Mukai J Asaka K Nakai Y Tsuji E Uchida T 《Chemical & pharmaceutical bulletin》2004,52(8):943-948
The purpose of this study was to evaluate the bitterness of 18 different antibiotic and antiviral drug formulations, widely used to treat infectious diseases in children and infants, in human gustatory sensation tests and using an artificial taste sensor. Seven of the formulations were found to have a bitterness intensity exceeding 1.0 in gustatory sensation tests (evaluated against quinine as a standard) and were therefore assumed to have an unpleasant taste to children. The bitterness intensity scores of the medicines were examined using suspensions in water or an acidic sports drink. In the case of three macrolide antibiotic formulations containing erythromycin (ERYTHROCIN dry syrup), clarithromycin (CLARITH dry syrup for pediatric), and azithromycin (ZITHROMAC fine granules for pediatric use), the bitterness intensities of suspensions in acidic sports drinks were dramatically enhanced compared with the corresponding scores of suspensions in water. This enhancement could be predicted using the taste sensor. On the other hand, a reduction of bitterness intensity was observed for an acidic sports drink suspension of an amantadine product (SYMMETREL fine granules) compared with an aqueous suspension. This reduction in bitterness could also be predicted using the taste sensor output value. Thus, the taste sensor could predict whether or not suspension in an acidic sports drink would enhance or reduce the bitterness intensity of pediatric drug formulations, compared with suspensions in water. 相似文献
9.
Ando K Tsuji E Ando Y Kunitomo J Kobayashi R Yokomizo T Shimizu T Yamashita M Ohta S Nabe T Kohno S Ohishi Y 《Organic & biomolecular chemistry》2005,3(11):2129-2139
Variable benzo[b]furan derivatives having (E)- and (Z)-2-alkylcarbamoyl-1-methylvinyl groups at the 2-, 4- and 5-positions and a carboxylpropoxy or (1-phenyl)ethoxy group at the 7-position were prepared to find novel and selective leukotriene B4(LTB4) receptor antagonists. (E)-2-(2-diethylcarbamoyl-1-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (4v) showed selective inhibition to the human BLT2 receptor (hBLT2). On the other hand, (E)-2-acetyl-4-(2-diethylcarbamoyl-1-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (7v) inhibited both human BLT(1) receptor (hBLT1) and hBLT2. The (E)-2-(2-diethylcarbamoyl-1-methylvinyl) group lay on approximately the same plane as the benzo[b]furan ring, whereas the (E)-4-(2-diethylcarbamoyl-1-methylvinyl) group had the torsion angle (45.7 degree) from the benzo[b]furan ring plane. However, the (Z)-(2-alkylcarbamoyl-1-methylvinyl)benzo[b]furans were inactive. The inhibitory activity depended on the conformation of the 2-diethylcarbamoyl-1-methylvinyl group. 相似文献
10.
Eriko Sato Per B. Zetterlund Bunichiro Yamada 《Journal of polymer science. Part A, Polymer chemistry》2004,42(23):6021-6030
α‐(2‐Methyl‐2‐phenylpropyl)acrylate (RS‐2) was examined as a C? C bond‐cleavage type addition–fragmentation chain transfer (AFCT) agent in the benzene solution polymerizations of styrene (St), ethyl methacrylate (EMA), and cyclohexyl acrylate (CHA) with the objective of achieving efficient macromonomer synthesis by radical polymerization. The AFCT efficiency was evaluated in terms of the decrease in the number‐average molecular weight (Mn) upon the addition of the AFCT agent and the number of unsaturated end groups introduced per chain (f). The AFCT efficiency was rationalized by the consideration of the relative importance of AFCT as an end‐forming event and the competition between ‐fragmentation and crosspropagation as adduct radical reaction pathways. In St and EMA polymerizations at 60 °C, RS‐2 resulted in higher f values and lower Mn values than methyl α‐(2‐methyl‐2‐carbomethoxypropyl)acrylate (MMA‐2), and this suggested the facilitation of ‐fragmentation due to the expulsion of the more stable cumyl radical from the RS‐2 adduct radical. Higher f values were observed for MMA‐2 than for RS‐2 in CHA polymerization because of unsaturated end group formation by ‐fragmentation of midchain radicals. However, RS‐2 resulted in lower Mn values for poly(CHA) than MMA‐2 because of a smaller contribution of crosspropagation. Retardation in the presence of the AFCT agents was affected by the balance between b‐fragmentation and crosspropagation and by the addition rate of the propagating radical to the AFCT agent. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6021–6030, 2004 相似文献