Yoshiharu Mitoma

Attomole detection of hemagglutinin molecule of influenza virus by combining an electrochemiluminescence sensor with an immunoliposome that encapsulates a Ru complex.

An immunoliposome (80 nm in diameter) encapsulating a Ru complex with two aminobutyl moieties was prepared to detect the presence of hemagglutinin molecules, which play an important role in influenza virus infection. The highly sensitive detection was accomplished by electrochemiluminescence (ECL) from the Ru complex adsorbed onto Au electrodes after competitive immunoreactions. This method clarified that the adsorption of the Ru complex onto the electrode was an important factor in obtaining high sensitivity. Optimization of the analytical conditions enabled determination of the hemagglutinin molecules of the influenza virus in the concentration range of 3 x 10(-14) (6 x 10(-19) mol/50 microL sample) to 2 x 10(-12) g/mL. The sensitivity was far superior to that obtained by conventional ELISA as well as to that obtained by biosensors and reported thus far.

Enhanced heavy metal immobilization in soil by grinding with addition of nanometallic Ca/CaO dispersion mixture

This study investigated the use of a nanometallic Ca and CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb) in contaminated soil. Simple grinding achieved 85-90% heavy metal immobilization, but it can be enhanced further to 98-100% by addition of a nanometallic Ca/CaO dispersion mixture produced by grinding. Observations using SEM-EDS elemental maps and semi-quantitative analysis showed that the amounts of As, Cd, Cr, and Pb measurable on the soil particle surface decrease after nanometallic Ca/CaO treatment. The leachable heavy metal concentrations were reduced after nanometallic Ca/CaO treatment to concentrations lower than the Japan soil elution standard regulatory threshold: <0.01 mg L(-1) for As, Cd, and Pb; and 0.05 mg L(-1) for Cr. Effects of soil moisture and pH on heavy metal immobilization were not strongly influenced. The most probable mechanisms for the enhancement of heavy metal immobilization capacity with nanometallic Ca/CaO treatment might be due to adsorption and entrapment of heavy metals into newly formed aggregates, thereby prompting aggregation of soil particles and enclosure/binding with Ca/CaO-associated immobile salts. Results suggest that the nanometallic Ca/CaO mixture is suitable for use in immobilization of heavy-metal-contaminated soil under normal moisture conditions.

Mechanochemical degradation of chlorinated contaminants in fly ash with a calcium-based degradation reagent.

This report presents our results in a low-temperature mechanochemical hydrodechlorination process applied to fly ash coming from a municipal waste incinerator in order to efficiently remove all traces of PCDDs, PCDFs and PCBs. We found that the most suitable degradation agent is a mixture of metallic calcium and calcium oxide. A sample of fly ash presenting a TEQ of 5200 pg g(-1) was completely detoxified (no traces of PCDDs, PCDFs and PCBs detected) after ball-milling at 400 rpm over night.

Organic reaction in water. Part 2. A new method for dechlorination of chlorobiphenyls using a Raney NiAl alloy in dilute aqueous alkaline solution

Abstract Use of a Raney Niue5f8Al alloy in dilute aqueous alkaline solution gave rise to strong reducing power and chlorobiphenyls were reduced easily to biphenyl and/or phenylcyclohexane, respectively, without any organic solvents.

Organic reaction in water. Part 4. New synthesis of vicinal diamines using zinc powder-promotedcarbon–carbon bond formation

Reductive coupling of aromatic imines is performed by the use nof zinc powder and additives such as NH4Cl and nL-tyrosine in water without any organic solvents under mild nconditions to give the corresponding vicinal diamines in good yields; ncross-coupling of N-benzylideneaniline and benzaldehyde similarly nproceeds in aqueous media to afford the corresponding 2-aminoalcohol.

Highly effective degradation of polychlorinated biphenyls in soil mediated by a Ca/Rh bicatalytic system.

Treatment of PCBs in soil using metallic calcium and alcohol ultimately reduced 1300 x 10(-3)mgkg(-1) PCB concentration to 1.8 x 10(-3)mg kg(-1). Moreover, using the metallic calcium catalyst method to promote the effective use of hydrogen gas in the presence of a specific reducing catalyst such as Rh/C, the decomposition efficiency of PCBs was notably increased despite mild reaction conditions. The total PCB concentration of treated soils decreased from 1300 x 10(-3)mg kg(-1) to 0.62 x 10(-3)mg kg(-1) (decomp. avg.=99.95%). Treatment of soils with metallic calcium and a Rh/C catalyst in alcohol under mild conditions such as 0.15-0.26 MPa at room temperature is extremely effective for degradation of existing PCBs.

Organic reaction in water. Part 1. A convenient method for reduction of imines using zinc powder

Abstract Reduction of imines was performed with zinc powder in 5% aq NaOH solution without any organic solvents under mild conditions, and the corresponding amines were obtained in good yields.

High immobilization of soil cesium using ball milling with nano-metallic Ca/CaO/NaH2PO4: implications for the remediation of radioactive soils

This report shows that cesium can be immobilized in soils with an efficiency of 96.4% by ball milling with nano-metallic Ca/PO4. In Japan, the major concern on 137Cs deposition and soil contamination due to the emission from the Fukushima Daiichi nuclear power plant showed up after a massive quake on March 11, 2011. The accident rated 7, the highest possible on the international nuclear event scale, released 160 petabecquerels (PBq) of iodine 131I and 15 PBq of 137Cs according to the Japanese Nuclear and Industrial Safety Agency. Both 137Cs and 131I radioactive nuclides are increasing cancer risk. Nonetheless, 137Cs, with a half-life of about 30xa0years compared with 8xa0days for 131I, is a major threat for agriculture and stock farming and, in turn, human life for decades. Therefore, in Japan, the 137Cs fixation and immobilization in contaminated soil is the most important problem, which should be solved by suitable technologies. Ball milling treatment is a promising treatment for the remediation of cesium-contaminated soil in dry conditions. Here, we studied the effect, factors and mechanisms of soil Cs immobilization by ball milling with the addition of nano-metallic Ca/CaO/NaH2PO4, termed “nano-metallic Ca/PO4.” We used scanning electron microscopy combined with electron dispersive spectroscopy (SEM/EDS) and X-ray diffraction. Results show that immobilization efficiency increases from 56.4% in the absence of treatment to 89.9, 91.5, and 97.7 when the soil is ball-milled for 30, 60 and 120xa0min, respectively. The addition of nano-metallic Ca/PO4 increased the immobilization efficiency to about 96.4% and decreased the ball milling time. SEM/EDS analysis allows us to observe that the amount of Cs decreased on soil particle surface. Use of nano-metallic Ca/PO4 over a short milling time also decreases Cs leaching. Therefore, ball milling with nano-metallic Ca/PO4 treatment may be potentially applicable for the remediation of radioactive Cs-contaminated soil in dry conditions.

Synthesis of imines, diimines and macrocyclic diimines as possible ligands, in aqueous solution

Although it is recognized that the presence of water is disadvantageous for imine synthesis, we demonstrate that such synthesis can be effective in completely aqueous media, without any catalyst and under mild conditions. Thus, aryl-aryl, aryl-alkyl, alkyl-aryl and alkyl-alkyl monoimines as well as a large variety of diimines are obtained by direct condensation of the corresponding carbonyl compounds and amines, in water. The same process is used to synthesize macrocyclic diimines starting from methylene, ethylene, trimethylene and tetramethylene glycol bis(2-formylphenyl ether) and ethylene-, trimethylene- and tetramethylene-diamine, some of these macrocycles being known for their chelating properties.

Dynamic immobilization of simulated radionuclide 133Cs in soil by thermal treatment/vitrification with nanometallic Ca/CaO composites

Although direct radiation induced health impacts were considered benign, soil contamination with (137)Cs, due to its long-term radiological impact (30 years half-life) and its high biological availability is of a major concern in Japan in the aftermath of the Fukushima nuclear power plant disaster. Therefore (137)Cs reduction and immobilization in contaminated soil are recognized as important problems to be solved using suitable and effective technologies. One such thermal treatment/vitrification with nanometallic Ca/CaO amendments is a promising treatment for the ultimate immobilization of simulated radionuclide (133)Cs in soil, showing low leachability and zero evaporation. Immobilization efficiencies were 88%, 95% and 96% when the (133)Cs soil was treated at 1200xa0°C with activated carbon, fly ash and nanometallic Ca/CaO additives. In addition, the combination of nanometallic Ca/CaO and fly ash (1:1) enhanced the immobilization efficiency to 99%, while no evaporation of (133)Cs was observed. At lower temperatures (800xa0°C) the leachable fraction of Cs was only 6% (94% immobilization). Through the SEM-EDS analysis, decrease in the amount of Cs mass percent detectable on soil particle surface was observed after soil vitrified with nCa/CaOxa0+xa0FA. The (133)Cs soil was subjected to vitrified with nCa/CaOxa0+xa0FA peaks related to Ca, crystalline phases (CaCO3/Ca(OH)2), wollastonite, pollucite and hematite appeared in addition to quartz, kaolinite and bentonite, which probably indicates that the main fraction of enclosed/bound materials includes Ca-associated complexes. Thus, the thermal treatment with the addition of nanometallic Ca/CaO and fly ash may be considered potentially applicable for the remediation of radioactive Cs contaminated soil at zero evaporation, relatively at low temperature.