Transplantation of hepatocytes cultured on hydroxyapatite into Nagase analbuminemia rats

Rat hepatocytes were seeded in porous hydroxyapatite (HA) disks for hepatocyte transplantation to Nagase analbuminemic rat (NAR). To increase the cell density in the HA, cell suspension in the tube containing the disks were centrifuged down. The centrifugation increased the viable cell number in HA disk approximately 4-fold over the static method. The HA disks were intraperitoneally transplanted into NARs and harvested three weeks after the transplantation. Angiogenesis with no obvious inflammatory reaction was found inside the pore areas of HA. The ectopic transplantation well supported the viability of hepatocytes seeded in HA disks evidenced by significant increases in the host rats' serum albumin level as time passed after the transplantation.     

Anisotropic Thermal Diffusivities of Plasma-Sprayed Thermal Barrier Coatings

Thermal barrier coatings (TBCs) are used to shield the blades of gas turbines from heat and wear. There is a pressing need to evaluate the thermal conductivity of TBCs in the thermal design of advanced gas turbines with high energy efficiency. These TBCs consist of a ceramic-based top coat and a bond coat on a superalloy substrate. Usually, the focus is on the thermal conductivity in the thickness direction of the TBC because heat tends to diffuse from the surface of the top coat to the substrate. However, the in-plane thermal conductivity is also important in the thermal design of gas turbines because the temperature distribution within the turbine cannot be ignored. Accordingly, a method is developed in this study for measuring the in-plane thermal diffusivity of the top coat. Yttria-stabilized zirconia top coats are prepared by thermal spraying under different conditions. The in-plane and cross-plane thermal diffusivities of the top coats are measured by the flash method to investigate the anisotropy of thermal conduction in a TBC. It is found that the in-plane thermal diffusivity is higher than the cross-plane one for each top coat and that the top coats have significantly anisotropic thermal diffusivity. The cross-sectional and in-plane microstructures of the top coats are observed, from which their porosities are evaluated. The thermal diffusivity and its anisotropy are discussed in detail in relation to microstructure and porosity.     

Investigation of Coxiella burnetii contamination in commercial milk and PCR method for the detection of C. burnetii in egg

A total of 244 milk samples collected from supermarkets in Tokyo were examined for contamination with Coxiella burnetii. C. burnetii DNA was detected in 131 (53.7%) of the samples by nested PCR. PCR-positive samples were injected into immunosuppressed A/J strain mice. Of the 22 PCR-positive milk samples tested, none resulted in isolation of C. burnetii from the mice. Heat-treatment was sufficient to inactivate C. burnetii in commercial milk. In addition, a PCR detection method for C. burnetii in chicken egg was developed. Egg yolk was added to an equal volume of 1 mol/L of NaCl phosphate buffer and homogenized for removal of protein and lipid. After centrifugal separation, the supernatant was removed, and template DNA in the precipitate was extracted using SDS, proteinase K and NaI. Using such prepared samples, 3.2 x 10(1) C. burnetii particles in 1 g of egg yolk could be detected by nested PCR. All of 200 chicken egg samples collected from supermarkets in Tokyo were negative for C. burnetii by the nested PCR method.     

Economic Analysis of Environmental Issues Regarding Seawater Desalination

Abstract

Desalination of seawater is becoming an important source of drinking water in many cities and towns, where the demand for water continues to increase, while the supply of fresh water is limited. We examine the economic aspects of several environmental issues that arise during consideration of desalination projects. We present a conceptual framework that demonstrates the differences between public and private objectives, and we use that framework to describe policies that can encourage firms and consumers to consider environmental impacts. Public policies can be implemented also to stimulate technological developments that will reduce the environmental impacts of desalination. We also examine the potential growth inducement effects of seawater desalination by describing the likely impacts of desalination on both the demand and supply components of the market for municipal water in a coastal area.     

Dynamic Resource Allocation in Non-orthogonal Multiple Access Using Weighted Maximin Fairness Strategy for a UAV Network

Non-orthogonal multiple access (NOMA) with power domain multiplexing and successive interference cancellation (SIC) is one of the promising technologies for future wireless communication. The performance of NOMA is highly dependent on resource allocation such as power allocation and channel assignment. In this paper, we investigate the power allocation (PA) scheme, to optimize the weighted maximin fairness (MMF) for 2-user and 3-user clusters. We utilize the particle swarm optimization (PSO) based algorithm for power allocation due to its promising behavior. Application area of NOMA is becoming broader, then, we considered a cellular network, assisted by an unmanned aerial vehicle (UAV) as the base station (BS) which is integrated with the NOMA system. The PA for weighted MMF problem in NOMA is non-convex, it is difficult to find out the optimal solution directly. Simulation results show the performance of PSO-based algorithm in different adaptive weights and its convergence characteristics. We have also shown that the rate and fairness tradeoff using weighted maximin fairness. Numerical results compare the performance of NOMA and orthogonal multiple access (OMA) and prove the significance of the proposed algorithm.

     

Suppressive effect of alkyl ferulate on the oxidation of microencapsulated linoleic acid

The oxidation processes of linoleic acid mixed with ferulic acid or the 1‐pentyl, 1‐hexyl and 1‐heptyl ferulates, encapsulated with gum arabic or maltodextrin, were studied. The alkyl ferulates had a higher antioxidative effect than ferulic acid, but there was no significant difference among the three alkyl ferulates. Suppression of the oxidation by 1‐hexyl ferulate or ferulic acid was more effective at the higher molar ratios of the additive to linoleic acid. The processes were analyzed using the Weibull equation to evaluate the rate constant, k, and the shape constant, n. Although the k values for linoleic acid encapsulated with gum arabic were lower than that with maltodextrin, the suppressive effect of the alkyl ferulates was more remarkable for linoleic acid encapsulated with maltodextrin than with gum arabic because of the non‐antioxidative ability of maltodextrin. Because the partition coefficient of the alkyl ferulates was much greater than that of ferulic acid, most of the alkyl ferulates would be located in the linoleic acid phase of the microcapsules and effectively suppress the oxidation of linoleic acid.     

Effect of amplification of desensitized purF and prs on inosine accumulation in Escherichia coli

The effect of a phosphoribosylpyrophosphate (PRPP) synthetase gene (prs) that was desensitized to feedback inhibition by ADP on inosine accumulation was investigated using an inosine-producing mutant of Escherichia coli. At the same time, various types of plasmid having a PRPP amidotransferase gene (purF) that was desensitized to feedback inhibition by AMP and GMP were also investigated to improve inosine productivity using a compatible plasmid containing prs with a plasmid containing purF. The recombinant E. coli I-9 harboring a low-copy-number plasmid having the desensitized-purF (pMWKQ) accumulated 3.6 g/l inosine from 40 g/l glucose in a 2-d culture. Furthermore, desensitized-prs amplification, in addition to purF, resulted in the accumulation of 6.2 g/l inosine. Additionally, through these experiments, a spontaneous mutant with an enhanced inosine-producing ability compared with the parent strain I-9 was obtained. The spontaneous mutant I-9m harboring only pMWKQ and I-9m harboring both pMWKQ and pSTVDA (a plasmid having the desensitized-prs) accumulated 6.7 g/l and 7.5 g/l inosine, respectively, from 40 g/l glucose in a 3-d culture.     

Inter-laboratory validation studies of biological method for determination of tetracyclines in royal jelly

Inter-laboratory validation studies were conducted in 5 laboratories to validate the biological method for determination of tetracyclines in royal jelly. Oxytetracycline spiked at the levels of 0.2 and 1.0 ppm was analyzed. Mean recoveries were 88 and 90%, reproducibility relative standard deviations (RSD(R)) were 13.7 and 7.8%, and HORRAT(R) values were 0.7 and 0.5. Samples containing residues at the levels of 0.25 and 0.80 ppm were analyzed. Mean recoveries were 73 and 77%, RSD(R) were 12.6 and 10.5%, and HORRAT(R) values were 0.6 and 0.6. The determination limit was 0.1 ppm (oxytetracycline, tetracycline) and 0.02 ppm (chlortetracycline). These results show that this method has good performance.