1,032 research outputs found

    A novel variant of the Calvin-Benson cycle bypassing fructose bisphosphate

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    The Calvin-Benson cycle (CB cycle) is quantitatively the most important metabolic pathway for CO2 fixation. In the canonical CB cycle, fructose 6-phosphate (F6P), fructose 1,6-bisphosphate (FBP), sedoheptulose 7-phosphate (S7P), and sedoheptulose 1,7-bisphosphate (SBP) appear as essential intermediates, where F6P is formed from FBP by the fructose 1,6-bisphosphatase (FBPase) reaction, and S7P is formed from SBP by the sedoheptulose 1,7-bisphosphatase (SBPase) reaction. Although the involvement of SBP and SBPase in the canonical CB cycle is consistent with the reported dependency of photosynthetic carbon metabolism on SBPase, the involvement of FBP and FBPase is not completely consistent with the reported FBP- or FBPase-related findings such as, although with a diminished growth rate, an Arabidopsis mutant lacking FBPase grew photoautotrophically in soil. Here, we show a novel variant of the CB cycle involving SBP, SBPase, and transaldolase, but neither FBP nor FBPase. This novel variant, named the S7P-removing transaldolase variant, bypasses FBP. This variant explains the FBP- or FBPase-related findings more easily than the canonical CB cycle as well as the dependency of photosynthetic carbon metabolism on SBPase and further suggests that co-overexpression of SBPase and transaldolase can be a strategy for enhancing photosynthetic carbon metabolism, which is important for the global environment

    Instability of the solitary waves for the generalized Boussinesq equations

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    In this work, we consider the following generalized Boussinesq equation \begin{align*} \partial_{t}^2u-\partial_{x}^2u+\partial_{x}^2(\partial_{x}^2u+|u|^{p}u)=0,\qquad (t,x)\in\mathbb R\times \mathbb R, \end{align*} with 0<p<0<p<\infty. This equation has the traveling wave solutions ϕω(xωt)\phi_\omega(x-\omega t), with the frequency ω(1,1)\omega\in (-1,1) and ϕω\phi_\omega satisfying \begin{align*} -\partial_{xx}{\phi}_{\omega}+(1-{\omega^2}){\phi}_{\omega}-{\phi}_{\omega}^{p+1}=0. \end{align*} Bona and Sachs (1988) proved that the traveling wave ϕω(xωt)\phi_\omega(x-\omega t) is orbitally stable when 0<p<4,0<p<4, p4<ω2<1\frac p4<\omega^2<1. Liu (1993) proved the orbital instability under the conditions 0<p<4,0<p<4, ω2<p4\omega^2<\frac p4 or p4,p\ge 4, ω2<1\omega^2<1. In this paper, we prove the orbital instability in the degenerate case 0<p<4,ω2=p40<p<4,\omega^2=\frac p4 .Comment: 29 page

    Factors Affecting Home Care of Elders Report 1. Support Expected by the Elderly and Family

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    For the rapid increase of the elders in population in Japan after the 2nd world war, the arrangement of medical care for aged persons, both therapeutic and preventive, has become the serious social problem. To estimate the possibility of care at home and needs of elders and their family for public and volunteer services, questionnaire survey was carried out at Konko town in Okayama prefecture, Japan, in August 1990. More than half of the 105 elders older than 65 years and living alone (group A, 9 males and 96 females) replied to want to be cared for at home and 178 families with elders (group B) wanted to care for them at home. As for services they would wish to be offered when they would become bedridden at home, while group A wished to be visited and cared for by 'physician', 'home helper' and 'neighbor' in order of high rate group B 'physician', 'public health nurse' and 'nurse'. As for facility or assistance services, the former wanted 'purchasing, sweeping and washing', food delivery' and 'calling on' and the latter 'care consultation', 'assist of body bath' and 'economic aid'. Other supports or cares were also hopefully expected by both groups. The results shows that well-arrangement and promotion of a variety of constitional and personal support for home cares for elders in the community must be urged

    Macroscopic visualization of fast electrochemical reaction of SrCoOx oxygen sponge

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    Strontium cobaltite (SrCoOx) is known as a material showing fast topotactic electrochemical Redox reaction so-called oxygen sponge. Although atomic scale phenomenon of the oxidation of SrCoO2.5 into SrCoO3 is known, the macroscopic phenomenon has not been clarified yet thus far. Here, we visualize the electrochemical oxidation of SrCoOx macroscopically. SrCoOx epitaxial films with various oxidation states were prepared by the electrochemical oxidation of SrCoO2.5 film into SrCoO3-d film. Steep decrease of both resistivity and the absolute value of thermopower of electrochemically oxidized SrCoOx epitaxial films indicated the columnar oxidation firstly occurred along with the surface normal and then spread in the perpendicular to the normal. Further, we directly visualized the phenomena using the conductive AFM. This macroscopic image of the electrochemical oxidation would be useful to develop a functional device utilizing the electrochemical redox reaction of SrCoOx.Comment: 24 pages, 5 figures, 5 supplementary figure

    Fe and Co-doped (Ba, Ca)TiO3 Perovskite as Potential Electrocatalysts for Glutamate Sensing

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    Barium titanate (BaTiO3) and calcium titanate (CaTiO3) are renown perovskite-structured dielectric materials. Nevertheless, utilization of BaTiO3 and CaTiO3 in sensing applications has not been extensive. This study, therefore, aims at examining potential usage of BaTiO3 and CaTiO3 as enzyme-less sensors. &nbsp;BaTiO3, CaTiO3, Fe-doped BaTiO3, Co-doped BaTiO3, Fe-doped BaTiO3, and Co-doped CaTiO3 (with Fe and Co 5 at%) were synthesized by solution combustion technique, compositionally and microstructurally examined, and tested for their electrocatalytic activities. All powders consisted of submicrometer-sized particles. Measurements of electrocatalytic activities in 0.01 M glutamate solution by cyclic voltammetry were performed. It was found that oxidation peaks occurred at applied voltage close to 0.6 V. Peak currents, which denoted electrocatalytic performance, were prominent in doped powders. Electrocatalytic activities of the powders were discussed with respect to chemical composition, microstructure, and electronic characteristic of the materials

    Reduction of 3-mercaptopyruvate in rat liver is catalyzed by lactate dehydrogenase.

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    It has been assumed that the in vivo reduction of 3-mercaptopyruvate, an intermediate of cysteine metabolism, to 3-mercaptolactate is catalyzed by lactate dehydrogenase (EC 1.1.1.27) though no definitive evidence has been presented. In order to examine this assumption, reduction of 3-mercaptopyruvate and its inhibition were studied using rat liver homogenate, lactate dehydrogenase purified from rat liver and anti-lactate dehydrogenase antiserum. Reduction of 3-mercaptopyruvate was actively catalyzed by rat liver homogenate and by the purified lactate dehydrogenase. This reducing activity was completely inhibited by anti-lactate dehydrogenase antiserum. These results indicate that the reduction of 3-mercaptopyruvate to 3-mercaptolactate in rat liver is catalyzed by lactate dehydrogenase.</p

    Post-Annealing Effects on the Structure and Semiconductor Performance of Nanocrystalline ZnTe Thin Films Electrodeposited from an Aqueous Solution Containing Citric Acid

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    Using the potentiostatic electrodeposition technique, zinc telluride nanocrystalline thin films and an array of nanowires were synthesized in a citric acid bath. Electrodeposited zinc telluride thin films with stoichiometric compositions were obtained at a cathode potential of approximately −0.8 V versus Ag/AgCl, which was in a more noble region compared with the equilibrium potential of zinc. The average thickness of the zinc telluride thin films was approximately 3 μm, and the average growth rate was approximately 3 nm s−1. The as-deposited zinc telluride thin films had an amorphous phase with a black tint. By contrast, the zinc telluride thin films annealed at 683 K had a crystalline phase with a reddish-brown tint. The electrodeposited single-phase zinc telluride exhibited an optical absorption performance in a wavelength region that was shorter than 559 nm. At the annealing temperature of 683 K, the zinc telluride films exhibited an energy band gap of 2.3 eV, which was almost identical to that of single-crystal zinc telluride. The resistivity of the as-deposited amorphous-like zinc telluride thin films was approximately 2 × 105 Ω·m, whereas that of the samples annealed at 683 K was around 2 × 103 Ω·m, which was smaller than that of single-crystal zinc telluride. A three-dimensional nanostructure constructed with the zinc telluride nanowire array was also demonstrated using a template synthesis technique
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