Syntheses and biodegradability of benzylated waste pulps and graft copolymers from PBzs and L‐lactic acid

Benzylated waste pulps (PBzs) were synthesized from treated waste pulp (Pulp), and benzyl chloride with phase transfer catalyst (PTC), and graft copolymers (PBz‐g‐LA) were synthesized from PBzs and L‐lactic acid (LA). Thermal properties, solubility, crystallinity, and biodegradability of the obtained PBzs and graft copolymers were investigated. PBzs with the degree of substitution (DS) higher than 1.5 showed T_g and T_m in DSC measurement. All PBz‐g‐LA exhibited no T_m. However, the graft copolymers obtained from lower DS PBzs having no T_g, exhibited T_g. The solubility of PBzs enhanced with increasing DS, and the crystallinity of PBzs reduced with increasing DS because of hydrophobicity and steric effect of benzyl groups. The solubility of graft copolymers was similar to that of original PBzs. Biodegradation tests for PBzs, Pulp, and graft copolymers were performed using cellulase in 0.1 M acetate buffer solution (pH 5.5) at 37°C. All samples showed biodegradability though the biodegradation rate decreased with increasing DS of PBz. In PBz‐g‐LA, the initial biodegradation rate was faster than that of original PBz because of hydrolysis of LA units. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2658–2664, 2004     

Resource Name-Based Routing in the Network Layer

New network architectures and routing technologies are being proposed to reflect the changes in the current trend of Internet communication that are becoming more and more resource-centric; the demand for the hierarchically structured resource in the network is emphasized, not the location of the resource. Therefore, routing by the resource rather than routing by the conventional Internet protocol address is more suitable for the future Internet with some attractive advantages such as reducing the burden of resolving identifier to location and achieving higher scalability by using a provider-independent addressing structure. In this paper, we propose resource name-based routing within the routers in the network layer since te ardware architecture should also be able to support the paradigm shift from host-centric to resource-centric communication. Through evaluating the required network architecture and memory size in routers, we show the feasibility of resource name-based routing by using fully qualified domain names (FQDN) as an example of describing structured information. Using approximately 700 million existing FQDNs, the evaluation result shows that resource name-based routing is feasible even when considering the limitations of ternary content addressable memory size in routers.     

A genetic network programming with learning approach for enhanced stock trading model

In this paper, an enhancement of stock trading model using Genetic Network Programming (GNP) with Sarsa Learning is described. There are three important points in this paper: First, we use GNP with Sarsa Learning as the basic algorithm while both Technical Indices and Candlestick Charts are introduced for efficient stock trading decision-making. In order to create more efficient judgment functions to judge the current stock price appropriately, Importance Index (IMX) has been proposed to tell GNP the timing of buying and selling stocks. Second, to improve the performance of the proposed GNP-Sarsa algorithm, we proposed a new method that can learn the appropriate function describing the relation between the value of each technical index and the value of the IMX. This is an important point that devotes to the enhancement of the GNP-Sarsa algorithm. The third point is that in order to create more efficient judgment functions, sub-nodes are introduced in each node to select appropriate stock price information depending on the situations and to determine appropriate actions (buying/selling). To confirm the effectiveness of the proposed method, we carried out the simulation and compared the results of GNP-Sarsa with other methods like GNP with Actor Critic, GNP with Candlestick Chart, GA and Buy&Hold method. The results shows that the stock trading model using GNP-Sarsa outperforms all the other methods.     

Data envelopment analysis for evaluating Japanese universities

In order to evaluate universities from various aspects, we propose a method of utilizing data envelopment analysis (DEA). The management of universities is complex, and it is necessary to find out their strengths and weaknesses so that they may become a better educational institute. In this sense, DEA contributes to the evaluation since it can show the efficiency of universities based on multiple viewpoints. However, when the number of universities evaluated is increased, the results of an evaluation are similar. Therefore, it is difficult to understand the specific points of each university. We propose a method for developing evaluations by adapting the decision-making unit (DMU) to certain viewpoints. The utility and effectiveness of the proposed method are shown by numerical experiments.     

Development and motion control of a biped walking robot based on passive walking theory

This research aims to develop the biped walking robot that can walk on the horizontal ground and improve walking efficiency by utilizing the theory of the passive walking robot, namely the pendulum principle. For that, two motors were installed on the hip of the robot to generate the control torques to perform a walking motion. The computer simulations with dynamic model were carried out to investigate the walking capability of the system. Experimental robot was developed considering the calculated results. The proportional control law was used in walking experiment. The robot can walk on the horizontal ground with the proposed method.     

Development and performance evaluation of a GC-FPD method for quantification of ethephon in feeds

An analytical method of ethephon in feeds by GC-FPD was developed. Ethephon was extracted with ethyl acetate-hydrochloric acid (100 : 1) from feed samples. The extract was treated with added trimethylsilyldiazomethane in acetone-acetic acid (99 : 1) and this methylation procedure was repeated three times. Methylated ethephon was cleaned up on a graphitized carbon mini-column and a silicagel mini-column, and determined by GC-FPD. A method performance study in 7 laboratories was conducted with three kinds of samples spiked with ethephon at 10 mg/kg, 1 mg/kg and 0.5 mg/kg. The recovery of ethephon ranged from 81.8% to 90.8% (the reproducibility standard deviation (RSDr) were within 11%) and HorRat values were 0.58 to 0.94. The limit of detection (S/N≧3) and the limit of quantitation (S/N≧10) of ethephon in samples except hay were 0.02 mg/kg and 0.05 mg/kg, respectively. In the case of hay, the corresponding values were 0.2 mg/kg and 0.5 mg/kg, respectively.     

Ceramide Metabolism Regulated by Sphingomyelin Synthase 2 Is Associated with Acquisition of Chemoresistance via Exosomes in Human Leukemia Cells

Ceramide levels controlled by the sphingomyelin (SM) cycle have essential roles in cancer cell fate through the regulation of cell proliferation, death, metastasis, and drug resistance. Recent studies suggest that exosomes confer cancer malignancy. However, the relationship between ceramide metabolism and exosome-mediated cancer malignancy is unclear. In this study, we elucidated the role of ceramide metabolism via the SM cycle in exosomes and drug resistance in human leukemia HL-60 and adriamycin-resistant HL-60/ADR cells. HL-60/ADR cells showed significantly increased exosome production and release compared with parental chemosensitive HL-60 cells. In HL-60/ADR cells, increased SM synthase (SMS) activity reduced ceramide levels, although released exosomes exhibited a high ceramide ratio in both HL-60- and HL-60/ADR-derived exosomes. Overexpression of SMS2 but not SMS1 suppressed intracellular ceramide levels and accelerated exosome production and release in HL-60 cells. Notably, HL-60/ADR exosomes conferred cell proliferation and doxorubicin resistance properties to HL-60 cells. Finally, microRNA analysis in HL-60 and HL-60/ADR cells and exosomes showed that miR-484 elevation in HL-60/ADR cells and exosomes was associated with exosome-mediated cell proliferation. This suggests that intracellular ceramide metabolism by SMS2 regulates exosome production and release, leading to acquisition of drug resistance and enhanced cell proliferation in leukemia cells.     

Contrasting Lubrication Properties of Imidazolium-Based Ionic Liquids Affected by the Nature of the Surface Under High Vacuum

The lubrication performance of imidazolium-based ionic liquids was evaluated under high vacuum using a ball-on-disk tribometer. A ball and a flat disk made of SUS440C stainless steel were used as specimens. A surface of the as-received flat disk specimen was covered with a thick oxide layer (>40 nm). For an examination of the effect of the surface oxide layer on the tribological performance of the ionic liquids under high vacuum, another specimen with a thin oxide layer (approx. 4 nm thick) was prepared. The ionic liquids with the TFSA anion showed better lubrication performance with the thicker oxide layer specimen, whereas the ionic liquids with the BF4 anion showed superior performance with the thinner oxide layer specimen. These results are discussed based on the HSAB principle. It is shown that the mechanism of the opposite tribological characteristics can be reasonably explained in terms of the chemical hardness by the HSAB principle.