A comparison of electrocatalytic ability of various mediators adsorbed onto paraffin impregnated graphite electrodes for oxidation of reduced nicotinamide coenzymes

Twelve mediators have been modified by adsorption onto the paraffin impregnated graphite electrodes (IGE). The resulting electrodes exhibit electrocatalytic activity of different degrees towards oxidation of 1,4-dihydronicotinamide adenine dinucleotide (NADH). The electrocatalytic ability of the chemically modified electrode (CME) depends mainly on the formal potential and molecular structure of mediator. The formation of the charge transfer complex between NADH and adsorbed mediator has been demonstrated by the experiments using a rotating disk electrode. An electrocatalytic scheme obeying Michaelis-Menten kinetics has been confirmed, and some kinetic parameters were estimated. The solution pH influences markedly the electrocatalytic activity of the modified electrode. Various possible reasons are discussed.

Toughening mechanism of polymer blends: Influence of voiding ability of dispersed-phase particles

The parameters which effect the cavitation strain of polymer blends toughened with a shear yield mechanism have been studied by analysis of the stress acted on the equatorial plane of dispersed-phase particles. As a result, the cavitation strain of polymer blends depends on the Young's modulus and the Poisson's ratio of the dispersed-phase particles and the matrix and also on the break stress of dispersed-phase particles. We tried to provide a criterion for selecting the materials used as dispersed-phase particles which can effectively enhance the toughness of polymer blends. (C) 1996 John Wiley & Sons, Inc.

A bioaugmentation failure caused by phage infection and weak biofilm formation ability

Two biological aerated filters (BAF) were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization (FISH) with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved differently and an overgrowth of protozoa was observed in the bioaugmented BAR Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, gazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9-18.

Transporting nutrients from sediments: nitrogen and carbon as indicators to measure scavenging ability of a detritivorous fish, Liza haematocheila

The redlip mullet, Liza haematocheila, is a common species in polyculture as a scavenger in China. Feeding on detritus, redlip mullet transports nutrients from sediments up into the water column and converts them into forms that can be utilized by phytoplankton and affects the relative abundance of detritus and dissolved inorganic nutrients to phytoplankton, zooplankton and other fishes. We used nitrogen and carbon as the indicators in this study to measure the scavenging ability, which means intake of nitrogen or carbon by redlip mullet, and the loss of nutrients. Temperature and body weight significantly affected growth nitrogen, faecal nitrogen and faecal carbon. At a certain temperature, the proportion of growth nitrogen or growth carbon increased while the proportion of excretion nitrogen or respiration carbon decreased with increasing body weight.

Molecular cloning, expression and biochemical property analysis of AtKP1, a kinesin gene from Arabidopsis thaliana

Kinesins are common in a variety of eukaryotic cells with diverse functions. A cDNA encoding a member of the Kinesin-14B subfamily is obtained using X-RACE technology and named AtKP1 (for Arabidopsis kinesin protein 1). This cDNA has a maximum open reading frame of 3.3 kb encoding a polypeptide of 1087 aa. Protein domain analysis shows that AtKP1 contains the motor domain and the calponin homology domain in the central and amino-terminal regions, respectively. The carboxyl-terminal region with 202 aa residues is diverse from other known kinesins. Northern blot analysis shows that AtKP1 is widely expressed at a higher level in seedlings than in mature plants. 2808 bp of the AtKP1 promoter region is cloned and fused to GUS. GUS expression driven by the AtKP1 promoter region shows that AtKP1 is mainly expressed in vasculature of young organs and young leaf trichomes, indicating that AtKP1 may participate in the differentiation or development of Arabidopsis thaliana vascular bundles and trichomes. A truncated AtKP1 protein containing the putative motor domain is expressed in E. coli and affinity-purified. In vitro characterizations indicate that the polypeptide has nucleotide-dependent microtubule-binding ability and microtubule-stimulated ATPase activity.

学习困难儿童智力结构及其与心理语言、视动能力关系的研究

IQ Structure, Psycholinguistic and Visual-motor Abilities Study on Children Learning Disability TONG Fang Directed by professor Zhu Liqi (Developmental and educational psychology) ABSTRACT Objective To comprehensive analyze the IQ structures, and relationships among IQ, psychometric characteristics and visual-motor integration on children disability. At same time, to probe into the family factors that influenced IQ, psycholinguistic abilities and behavior of LD children. Method (1) Downloading the papers on children learning disability from www.cqvip.com and www.wanfangdata.com, in which, the articles were collected by key words from 1985 to 2005. To conduct meta-analysis on IQ construction, compare the case group and the control group, including full IQ, verbal and practice IQ. (2) Designed with model compared and self-compared, 59 diagnosed learning disability children, tested themes with WISC, ITPA and Berry’s VMI. WISC included 10 items, 5 of which subtotal to verbal and practice IQ respectively. IPTA included 10 items, too, 5 process of which subtotal to auditory and visual perception. The first 3 items shared representation level, the other 2 of that shared automatic level.VMI had one score. Analyzed factors and levels with description and Pearson Correlation. To probe to linguistic internal alternately functions of LD children, and compare the scores of groups in different IQ. (3) Analyzed the perspective questionnaire filled by parents. Early development facts compared with model groups. Factors relationships analyzed with Kendall correlation, KOM and Bartlett’s test of sphericity, Promax Rotation. Results: (1) There have been 319 papers related with LD, in which 36 with IQ and 14 valid reports have been analyzed by Meta. FIQ’s 95%CI (confidence interval) is 2.418 ~ 0.172, VIQ between the difficulty and non- difficulty group. C-WISC-R reports were 10 papers, of which, 95%CI of FIQ is 2.424 ~ 0.676, of VIQ is 2.314 ~ 1.196, of PIQ is 2.176 ~ 0.176. The VIQ comparing the PIQ, 95%CI is 1.1 ~ -0.07 in difficulty group and 0.5 ~ -0.0046 in non-difficult group. Nevertheless, in the other 4 tests, FIQ’s 95%CI is 2.00 ~ -0.818 between LD and NLD. (2) Children psycholinguistic abilities had strong relation with Berry’s VMI test excluding auditory reception, and with perceptive factor of intelligence excluding verbal expression. Auditory reception and visual closure had strong relation with FIQ and PIQ. Grammatic closure, visual association and manual expression had strong relation with concept factor. The representational and automatic levels are depended on integration of auditory and visual procession. Lower verbal expression (VE) let to lower expression process and low scores on representational level. Lower visual sequential memory (VSM) let to lower memory process and influenced automatic level. Groups compared by IQ 90 show that LD children with under IQ 90 had lower scores on items of IPTA than with up IQ 90 excluded verbal expression. It was proved that IQ administrated the linguistic ability. Nevertheless, general abilities deficiency didn’t show influencing on the types of the perceptive delay. There was mutual function among linguistic ability on LD children. Auditory and visual level are overlapped each other. Not only show higher Decoding and lower Encoding on Auditory perception, lower Decoding and higher Encoding on Visual perception, in representation, but also higher Sequential remember, lower Closure on Audition, and lower Sequential member, higher Closure on Vision, in Automation. Nevertheless, there was no different between Representational and Automatic level, which may be the relationship of parallel or evolution. (3) Major family factors were father’s education, occupation. Lower auditory perception related to unconcerned, lower visual perception related to premature delivery and written slowly. Threatened–abortion, childbirth-suffocated were known as influencing children’s IQ and later linguistic abilities. It wasn’t shown that dosage relationship with the types of perceptive delay. Conclusion: (1) The FIQ, VIQ and PIQ of Children with LD is lower than that of NLD group. There is no significantly different between VIQ and PIQ in LD and NLD groups. (2) The objectives of ITPA and WISC tests are differently. The psycholinguistic abilities had strong relation with perceptive factor and VMI. Some facts of IPTA related with FIQ. IQ had strong administration on linguistic abilities. There was mutual function among linguistic internal abilities. (3) Family facts on IQ and psycholinguistic abilities were Father’s education, abnormal pregnant and abortion. It would be pre-show development delay in early period.