Hiroshi Kimura

Interspecies transmission of influenza C virus between humans and pigs

The antigenic and genetic characteristics of the 18 human strains of influenza C virus isolated in Yamagata and Sendai Cities, Japan between January 1991 and February 1993 were investigated. Antigenic analysis with monoclonal antibodies to the hemagglutinin-esterase glycoprotein showed that the isolates could be divided into three distinct groups closely related to C/Yamagata/26/81, C/Aichi/1/81 and C/Mississippi/80, respectively. T1-oligonucleotide fingerprinting of total vRNA revealed that the six isolates belonging to the C/Yamagata/26/81 virus group had the genomes greatly similar to one another but considerably different from those of the 1988/1990 isolates (except C/Yamagata/10/89) of the same antigenic group. Comparison of total or partial nucleotide sequences of the seven RNA segments of the three strains (C/Miyagi/3/91, C/Miyagi/9/91 and C/Miyagi/2/92) representative of the 1991/1993 strains of the C/Yamagata/26/81 virus group with those of the previous influenza C isolates obtained from humans and pigs during 1980/1989 showed that the 1991/1993 strains, like C/Yamagata/10/89, are more closely related to viruses isolated from pigs in Beijing, China in 1981/1982 than to any of the isolates from humans. This observation suggests strongly that interspecies transmission of influenza C virus between humans and pigs has occurred in nature, although it is not known whether the virus has been transmitted from pigs to humans or from humans to pigs.

Production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) byPseudomonas acidovorans

SummaryTerpolyesters of 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB) and 3-hydroxyvarelate (3HV) were produced byPseudomonas acidovorans in nitrogen-free culture solutions of 1,4-butanediol and pentanol. When 1,4-butanediol was used as the sole carbon source, a polyester with an unusually high 4HB fraction of 99 mol% was produced.

In Situ Kinetic Study on Hydrothermal Transformation of d-Glucose into 5-Hydroxymethylfurfural through d-Fructose with 13C NMR

Kinetics of hydrothermal reaction of D-glucose was investigated at 0.02 M over a temperature range of 120-160 °C by applying in situ (13)C NMR spectroscopy. D-Glucose was found to be reversibly transformed first into D-fructose (intermediate) and successively into 5-hydroxymethylfurfural (5-HMF) through dehydration. The carbon mass balance has been kept within the detection limit, and no other reaction pathways are present. The hydrothermal reaction of d-glucose is thus understood as that of D-fructose in the sense that the D-glucose reaction proceeds only through D-fructose. All the isomers of D-glucose and D-fructose were detected by the in situ (13)C NMR in D(2)O: they are the open chains and the pyranoses and furanoses of α- and β-types. The β-forms are the most stable due to the hydration. For both D-glucose and D-fructose, the isomers are in a rapid equilibrium for each monosaccharide, and they are treated collectively in the kinetic analysis of the slower hydrothermal reactions. The reactions are of the first order with respect to the concentrations of D-glucose and D-fructose, and D-glucose converts to 5-HMF on the order of hours. The kinetic parameters were determined by the in situ method.

`Positive' and `negative' electro-rheological effect of liquid blends

The electrorheological (ER) effect of urethane-modified polypropylene glycol (UPPG)/dimethylsiloxane (DMS) blends was investigated by rheological measurement and observation of the domain structure under shear flow. It was found that: (i) the cause of an ER effect is in close association with the domain composition under no electric field; the ER effect appears when UPPG forms droplets, while when it forms a continuous phase, the ER effect does not appear; (ii) UPPG droplets elongate and bridge between the electrodes when an electric field is applied and the bridges remain even under the shear; and (iii) the ER effect is positive in the case that the viscosity of UPPG is larger than that of DMS and negative in the case that the viscosity of UPPG is smaller than that of DMS. The cause of both positive and negative ER effects for UPPG/DMS blends is the connection of UPPG between electrodes under the electric field.

Investigation of in Situ Oxalate Formation from 2,3-Pyrazinedicarboxylate under Hydrothermal Conditions Using Nuclear Magnetic Resonance Spectroscopy

We have investigated the assembly of a two-dimensional coordination polymer, Nd(2)(C(6)H(2)N(2)O(4))(2)(C(2)O(4))(H(2)O)(2), that has been prepared from the hydrothermal reaction of Nd(NO(3))(3)·6H(2)O and 2,3-pyrazinedicarboxylic acid (H(2)pzdc). In situ oxalate formation as observed in this system has been been investigated using (1)H and (13)C nuclear magnetic resonance spectroscopy, and a pathway for C(2)O(4)(2-) anion formation under hydrothermal conditions has been elucidated. The oxalate ligands found in Nd(2)(C(6)H(2)N(2)O(4))(2)(C(2)O(4))(H(2)O)(2) result from the oxidation of H(2)pzdc, which proceeds through intermediates, such as 2-pyrazinecarboxylic acid (2-pzca), 2-hydroxyacetamide, 3-amino-2-hydroxy-3-oxopropanoic acid, 2-hydroxymalonic acid, 2-oxoacetic acid (glyoxylic acid), and glycolic acid. The species are generated through a ring-opening that occurs via cleavage of the C-N bond of the pyrazine ring, followed by hydrolysis/oxidation of the resulting species.

Solvent Effect on Pathways and Mechanisms for d-Fructose Conversion to 5-Hydroxymethyl-2-furaldehyde: In Situ 13C NMR Study

Noncatalytic reactions of D-fructose were kinetically investigated in dimethylsulfoxide (DMSO), water, and methanol as a function of time at temperatures of 30-150 °C by applying in situ (13)C NMR spectroscopy. The products were quantitatively analyzed with distinction of isomeric species by taking advantage of site-selective (13)C labeling technique. In DMSO, D-fructose was converted first into 3,4-dihydroxy-2-dihydroxymethyl-5-hydroxymethyltetrahydrofuran having no double bond in the ring, subsequently into 4-hydroxy-5-hydroxymethyl-4,5-dihydrofuran-2-carbaldehyde having one double bond through dehydration, and finally into 5-hydroxymethyl-2-furaldehyde (5-HMF) having two double bonds. No other reaction pathways were involved, as shown from the carbon mass balance. In water, 5-HMF, the final product in DMSO, was generated with the precursors undetected and furthermore transformed predominantly into formic and levulinic acids and slightly into 1,2,4-benzenetriol accompanied by polymerization. D-glucose was also produced through the reversible transformation of the reactant D-fructose. In methanol, some kinds of anhydro-D-fructoses were generated instead of 5-HMF. The reaction pathways can thus be controlled by taking advantage of the solvent effect. The D-fructose conversion reactions are of the first order with respect to the concentration of D-fructose and proceed on the order of minutes in DMSO but on the order of hours in water and methanol. The rate constant was three orders of magnitude larger in DMSO than in water or methanol.

Characterization of antigenically unique influenza C virus strains isolated in Yamagata and Sendai Cities, Japan, during 1992-1993

Three influenza C virus strains (C/Yamagata/1/92, C/Yamagata/1/93 and C/Miyagi/5/93) isolated in Yamagata and Sendai Cities, Japan, between June 1992 and May 1993 were found to possess haemagglutinin-esterase glycoproteins that were antigenically indistinguishable from one another but were clearly different from any previous Japanese isolates. To investigate the origin of the 1992/1993 strains, their antigenic and genetic properties were compared with those of eight strains isolated outside Japan between 1967 and 1982. The results showed that the 1992/1993 isolates were closely related to a virus isolated in Brazil in 1982 (C/SaoPaulo/378/82) and that these viruses (including C/SaoPaulo/378/82) are reassortants that had obtained PB1 and NP genes from a C/Yamagata/26/81-like parent and the other genes from another as yet unidentified parent.

Nuclear magnetic resonance study on rotational dynamics of water and benzene in a series of ionic liquids: Anion and cation effects

The rotational correlation times (τ(2R)) for polar water (D(2)O) molecule and apolar benzene (C(6)D(6)) molecule were determined in ionic liquids (ILs) by means of the (2)H (D) NMR spin-lattice relaxation time (T(1)) measurements. The solvent IL was systematically varied to elucidate the anion and cation effects separately. Five species, bis(trifluoromethylsulfonyl)imide (TFSI(-)), trifluoromethylsulfonate (TfO(-)), hexafluorophosphate (PF(6)(-)), chloride (Cl(-)), and formate (HCOO(-)), were examined for the anion effect against a fixed cation species of 1-butyl-3-methyl-imidazolium (bmim(+)). Four species, bmim(+), N-methyl-N-butylpyrrolidinium (bmpy(+)), N,N,N-trimethyl-N-propylammonium (N(1,1,1,3)(+)), and P,P,P-trihexyl-P-tetradecylphosphonium (P(6,6,6,14)(+)), were employed for the cation effect against a fixed anion species of TFSI(-). The τ(2R) ratio of water to benzene, expressed as τ(W/B), was used as a probe to characterize the strength of Coulombic solute-solvent interaction in ILs beyond the hydrodynamic limit based on the excluded-volume effect. The τ(W/B) value was found to strongly depend on the anion species, and the solute dynamics are sensitive not only to the size but also to the chemical structure of the component anion. The cation effect was rather weak, in contrast. The largest and most hydrophobic P(6,6,6,14)(+) cation was exceptional and a large τ(W/B) was observed, indicating a unique solvation structure in [P(6,6,6,14)(+)]-based ILs.

Effective microbial production of poly(4-hydroxybutyrate) homopolymer by Ralstonia eutropha H16

The effective microbial production of copolyesters of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) with high mole fractions of 4HB units by a wild-type strain of Ralstonia eutropha H16 was investigated in culture solutions containing 4-hydroxybutyric acid (4HBA) and various carbon substrates in the presence of a nitrogen source such as ammonium sulfate. The addition of glucose or acetic acid to the culture solution containing 4HBA in the presence of ammonium sulfate resulted in the production of random copolymers of P(3HB-co-4HB) with compositions of up to 82u2009mol% 4HB, but the yield of copolymers was less than 7u2009wt% of dried cell weights. In contrast, when n-alkanoic acids such as propionic acid, butyric acid, valeric acid and hexanoic acid, being subject to β-oxidation metabolism in the cell, were used as the co-substrates of 4HBA in the presence of ammonium sulfate, a mixture of copolymers with two different 4HB compositions was produced, and copolyesters with compositions of 93–100u2009mol% 4HB were isolated from chloroform–n-hexane insoluble fractions in the mixture of copolymers. Especially, when this wild-type Ralstonia eutropha H16 was cultivated in a medium containing 4HBA (15u2009g litre−1), propionic acid (5u2009g litre−1) and ammonium sulfate (5u2009g litre−1), namely C/N (mol/mol)u2009=u200910, the P(4HB) homopolymer was produced at maximally 34u2009wt% of dry cell weight (7.8u2009g litre−1), and the conversion yield of 4HBA to P(4HB) homopolymer resulted in values as high as 21u2009mol%. n n n n© 1999 Society of Chemical Industry

Effect of water content on conversion of D-cellobiose into 5-hydroxymethyl-2-furaldehyde in a dimethyl sulfoxide-water mixture.

Noncatalytic conversion of D-cellobiose (at 0.5 M) into 5-hydroxymethyl-2-furaldehyde (5-HMF), a platform chemical for fuels and synthetic materials, was analyzed at 120-200 °C over a wide range of water mole fraction, xw = 0.007-1 in a binary dimethyl sulfoxide (DMSO)-water mixture by means of the in situ (13)C NMR spectroscopy. Effects of the water content were revealed as follows: (i) The tautomerization of the anomeric residue of D-cellobiose from D-glucose to D-fructose type was not initially observed at a lower water content, in contrast to the significant tautomerization into the D-fructose type in a higher water content and pure water. (ii) The lower the water content, the faster the glycosidic-bond cleavage by hydrolysis, because of the high reactivity of solitary water molecules with the large partial charges more naked as in supercritical water clusters due to the isolation by the organic solvent DMSO. (iii) The amount of D-fructose as the intermediate product was larger at the higher xw; despite the increase of D-fructose, the production of 5-HMF from D-fructose was slowed down. (iv) A high 5-HMF yield of 71% was reached at xw = 0.20-0.30 that was 6-10 times the initial D-cellobiose concentration. The best yield of 5-HMF was attained in the low xw region when the polymerization paths into NMR-undetectable species via 5-HMF and anhydromonosaccharides were effectively suppressed. This study provides a new framework to design optimal, noncatalytic reaction process to produce 5-HMF from cellulosic biomass by tuning the water content as well as the temperature and the reaction time.