Cloning and expression of the gene encoding the thermophilic NAD(P)H-FMN oxidoreductase coupling with the desulfurization enzymes from Paenibacillus sp. A11-2

The gene encoding the NAD(P)H-flavin oxidoreductase (flavin reductase) which couples with the thermophilic dibenzothiophene (DBT)-desulfurizing monooxygenases of Paenibacillus sp. A11-2 was cloned in Escherichia coli and designated tdsD. Nucleotide sequence analysis suggested that the gene product consisted of 200 amino acids and showed about 30%, 27% and 26% amino acid sequence similarity to the major flavin reductase of Vibrio fischeri, the NADH dehydrogenase of Thermus thermophilus and several oxygen-insensitive NAD(P)H nitroreductases in the Enterobacteriaceae family, respectively. Both the growing and resting recombinant E. coli, in which tdsD was coexpressed with a set of desulfurizing genes, showed a rate of DBT removal about 5 times higher than the recombinants lacking tdsD. Maximal desulfurization was observed close to 45°C and 55°C in the resting cells and in the cell-free extraction reaction with the tdsD-coexpressing recombinants, respectively. In an organic/aqueous biphasic system, the coexpression of tdsD also markedly enhanced the rate of DBT removal.     

Effective Catalysts for Wet Oxidation Of Formic Acid by Oxygen and Ozone

The catalytic wet-air oxidation and catalytic ozonation of a formic acid solution have been studied at room temperature using more than 20 kinds of catalysts including Pt/C, Pt/Al₂O₃, Pd/Al₂O₃, etc. The most effective catalyst was Pt/Al₂O₃. The apparent activation energies for the catalytic wet-air oxidation and ozonation on Pt/Al₂O₃ were both about 5 kcal/mol. This fact suggests that these reactions on the catalyst were diffusion controlled, and thus, the potential of the catalyst is likely much higher.     

Effect of Atmosphere on Weight Loss in Sintered Silicon Carbide during Heat Treatment

Heat treatment was performed on β-SiC with different sintering additives in the temperature range 1873–2073 K, in both argon and nitrogen-gas atmospheres. In the case of the specimens heat-treated at 2073 K in argon, the weight loss was more than the total weight of the sintering additives, except for B,C-doped β-SiC. On the other hand, weight loss was suppressed by about one-third to one-half in nitrogen gas. Weight loss depended mainly on the reaction at the interface between the SiC grains and the grain-boundary phase.     

Stability of the molten globule state of a domain-exchanged chimeric protein between human and bovine {alpha}-lactalbumins

A domain-exchanged chimeric     

Scenario analysis of bioenergy resources and CO2 emissions with a global land use and energy model

The purpose of the present study is to evaluate bioenergy supply potentials, land use changes, and CO₂ emissions in the world, using a global land use and energy model (GLUE) including land use competitions and overall biomass flows. Through a set of simulations, the following results were obtained: (1) Supply potentials of energy crops produced from surplus arable lands will be strongly affected by food supply and demand parameters in the future, such as animal food demand per capita. (2) The policy option, i.e. the world, large-scale introduction of modern fuelwood by felling and planting in existing forest, will cause drastic reduction of the mature forest area but will cause little reduction of the accumulated CO₂ emissions coming from both energy and forest sectors. One reason for this is that the additional CO₂ emissions owing to the land use conversion from the mature forest to the growing forest will partly cancel out the CO₂ reduction owing to the fuel substitution from fossil fuels to fuelwood. (3) When energy recovery of paper scrap is given priority to material recycling, bioenergy will substitute partly for fossil fuels; however the decrease in recycled paper scrap will cause an increase in roundwood felling demand. Hence, the results will be similar to those of (2).     

Silicone-containing polymer blend electrolyte membranes for fuel cell applications

Polymer electrolyte membranes are developed from blends of chemically durable silicone-containing epoxy (Si-Epoxy) and proton conducting sulfonic polyimide (SPI). A charge-transfer (CT) complex is formed between electron-donating dihydroxynaphthalene units in Si-Epoxy, and electron-accepting naphthalenediimide units in SPI, as confirmed via X-ray diffraction and visible spectroscopy. The blend membranes show comparable mechanical strength to Nafion 211, but the elongation to break is much lower, indicating better resistance to deformation under strain stress, attributed to CT complex formation. The chemical durability of the blend membranes was much higher than pure SPI according to Fenton's test, also attributed to CT complex formation. Meanwhile, the proton conductivity is dependent on the sulfonic acid content of the SPI, which in turn affects the fuel cell performance. The maximum proton conductivity was measured to be 23.1 mS cm⁻¹ at 80°C and 90 %RH for a 1:1 blend, and the membranes were successfully incorporated into PEFCs.     

Autonomous battery management for mobile robots based on risk and gain assessment

Battery management of mobile robots is an issue that has not been a strong focus of attention and is usually addressed by the simple use of battery thresholds. One of the main causes is that no significant method of assessment of risk of battery depletion has yet been proposed. As a result decision of redirection to a charging station is fixed and takes into account neither a dynamic evaluation of the risk of battery depletion nor an evaluation of the gain, defined as the level of mission accomplishment that could be achieved. In this paper we propose a novel method for evaluation of risk of battery depletion for mobile robots. Uncertainties concerning effective battery capacity, current discharge rate and energy required for reaching the station are addressed by the use of probability density functions. This risk assessment will allow replacing the usage of battery threshold by a customizable risk-taking parameter that will be used to define what level of gain is required for balancing a given level of risk. This risk/gain management of battery will guarantee that decision of redirection to the station corresponds to a favorable compromise between risk and level of mission accomplishment. While the proposed approach has been tested using a simulated and real room cleaning robot, it could be applied on a wider range of mobile robots.     

Effect of legume seed extracts on the inhibition of proteolytic activity and muscle degradation of fresh water prawn (Macrobrachiumrosenbergii)

Trypsin inhibitors in the extracts from soybean (Glycine max), adzuki bean (Vigna angularis), bambara groundnut (Vigna subterranea) and red kidney bean (Phaseoulus vulgaris) varied in amount and molecular weight. The soybean extract had the highest level of trypsin inhibitor with molecular weight (MW) of 21 kDa, followed by bambara groundnut extract possessing trypsin inhibitor with MW of 15 kDa. Both extracts showed a more effective inhibition towards crude protease extract (CE) from the hepatopancreas of fresh water prawn (Macrobrachium rosenbergii) than the extracts from adzuki and red kidney beans. Activity staining also reconfirmed the higher inhibitory activity on CE from hepatopancreas by the extracts from both soybean and bambara groundnut. The extracts from all seeds were able to inhibit the degradation of fresh water prawn meat containing CE in a concentration dependent manner. Based on inhibitor study, the extracts from soybean and bambara groundnut can be a potential aid to suppress the muscle softening of fresh water prawn, mediated by trypsin-like proteases released from hepatopancreas, during extended iced storage.