Acylation of anthocyanins with hydroxycinnamic acid derivatives is one of the most important and less under-stood modification reactions during anthocyanin biosynthesis. Anthocyanin aromatic acyltransferase catalyses the transfer of hydroxycinnamic acid moieties from their CoA esters to the glycosyl groups of anthocyanins. A full-length cDNA encoding the anthocyanin 5-aromatic acyltransferase (5AT) (EC 2.3.1.153) that acylates the glucose bound at the 5-position of anthocyanidin 3,5-diglucoside was isolated from petals of Gentiana triflora on the basis of the amino acid sequence of the purified enzyme. The isolated full-length cDNA had an open reading frame of 469 amino acids and the calculated molecular weight was 52,736. The deduced amino acid sequence contains consensus motifs that are conserved among the putative acyl CoA-mediated acyltransferases, and this indicates that 5AT is a member of a proposed superfamily of multi-functional acyltransferases (St-Pierre et al. (1998) Plant J. 14, 703-713). The cDNA was expressed in Escherichia coli and yeast, and confirmed to encode 5AT. The enzymatic characteristics of the recombinant 5AT were consistent with those of the native gentian 5AT. Immunoblot analysis using specific antibodies to 5AT showed that the 5AT protein is present in petals, but not in sepals, stems or leaves of G. triflora. RNA blot analysis showed that the 5AT gene is expressed only in petals and that its expression is temporally regulated during flower development coordinately with other anthocyanin biosynthetic genes. Immunohistochemical analysis demonstrated that the 5AT protein is specifically expressed in the outer epidermal cells of gentian petals and that it is localized mainly in the cytosol. 相似文献
Phase equilibria in the CaO─CuO─Cu system were determined at 1173 K from the results of X-ray diffraction measurements using specimens annealed in the oxygen partial pressure range from P O2= 1 to 10−8 atm. Electromotive force (emf) measurements using ZrO2 solid electrolyte cells were carried out in the ternary phase equilibria. Gibbs free energies for the chemical reactions were summarized by equations with linear temperature dependence, and the standard free energy of formation for Ca2CuO3 was derived. The stability conditions of the oxides are displayed in the p – T – x diagram, and the possible phase equilibria with the liquid are evaluated. 相似文献
Phase equilibria on the Fe-Cu side in the Fe-Cu-X (X: Co, Cr, Si, V) system were experimentally determined over the temperature
range of 1073–1273 K. Based on the present results and previous works, the thermodynamic assessments of the phase equilibria
in the Fe-Cu-X system were evaluated using the Calculation of Phase Diagram (CALPHAD) method. The Gibbs energies (G) of the bcc, fcc, and liquid phases are described by the subregular solution model, and a set of thermodynamic parameters
enable us to calculate various isothermal and vertical sections and the miscibility gaps of the solid and liquid phases. 相似文献
For identifying human or finger movement, it is necessary to sense subtle movements at multiple points, including the local strain and global deformation simultaneously; however, this has not yet been realized. Therefore, a highly stretchable, global, and distributed local strain sensing electrode made of GaInSn and polydimethylsiloxane is developed for wearable devices. To investigate the electrical properties of multiple sections of the GaInSn electrode when stretching, tensile, cyclic, and three‐point‐bending tests are performed. The results demonstrate that the electrode can withstand a strain up to 50% and has little hysteresis without any delay. Moreover, the distributed local strain and global strain can be simultaneously measured using just a single electrode line. Finally, a prototype of a data glove as an application of the strain sensing line is manufactured, and it is demonstrated that the folding state of fingers could be identified. The proposed technology may allow the creation of a lightweight master hand manipulator or 3D data entry device. 相似文献
The possible use of ozone to produce higher oxides was analyzed thermodynamically. Because the activity of oxygen in ozone is ∼1018 at room temperature and ∼108 at 773 K, ozone may react with metals to yield higher-oxidation-state products than does an ambient pressure of pure oxygen. In agreement with this thermodynamic prediction, silver oxides (AgO and Ag2O) were synthesized experimentally by blowing a gas mixture of 6 vol% ozone and oxygen through a water-cooled lance. Neither Ag3O4 nor Ag2O3 was detected. Slow oxygen diffusion into a metal and/or reaction products and decomposition of unstable oxides that are formed successively are obstacles to practical applications of syntheses via ozone oxidation. 相似文献
A computer-controlled compression testing machine is used to compile a database of the static cushioning properties of package cushioning materials. Through research into automated data input procedures, so far not developed, a direct transfer program (ZABCON) has been devised, which allows direct access to the disk in which compression test data are stored. Elimination of manual data input has led to simplified and easy construction of a database, and the applied laboratory tests, such as that for determining the relationship between static cushioning properties and compression rate, can be performed quite readily. Also in this report, the application of the static cushioning characteristics of foamed polystyrene in the cushioning package design of dummy goods and the evaluation of its reliability by drop testing are discussed. 相似文献
Chemical reactions between Cu substrates and Zn-Al high-temperature solder alloys, Zn-4Al and Zn-4Al-1Cu (mass%), at temperatures
ranging from 420°C to 530°C were experimentally investigated by a scanning electron microscope using backscattered electrons
(SEM-BSE) and an electron probe microanalyzer (EPMA). Intermediate phases (IMPs), β(A2) or β′(B2), γ(D82), and ε(A3) phases formed and grew during the soldering and aging treatments. The consumption rate of the IMP for Cu substrates
is described by the square root of t in both the alloys, while the additional Cu in the molten Zn-Al alloy slightly suppresses the consumption of Cu substrates.
The growth of IMPs during soldering treatment is controlled by the volume diffusion of constituent elements, and its activation
energy increases in the order of Qε < Qγ < Qβ. In view of the aging process, the growth of IMPs is considered to be controlled by the volume diffusion. In particular,
the layer thickness of γ rapidly grows over 200°C, although the thickness of the β layer grows very slowly. 相似文献
The effects of CoCl(2) on retinoic acid (RA)-treated embryoid bodies (EBs) were investigated. Four-day EBs were treated with 5x10(-6) M of RA for 4 d, then subjected to attached culturing for 7 d in the presence of CoCl(2) at 0, 20, and 100 microM. Differentiation into MAP2- and GFAP-immunopositive cells was inhibited by CoCl(2) in a dose-dependent manner. Next, RA-treated EBs were dissociated into single cells and cultured for 7 d at an initial cell density of 1x10(3)/cm(2). The number of cells increased in a CoCl(2)-dose dependent fashion. In cultures with 100 microM of CoCl(2), more than 90% of the cells were immunopositive for nestin and nestin-immunopositive cells formed clusters, while there were few cells immunopositive for MAP2 or GFAP. These results suggest that CoCl(2) inhibits neural differentiation of RA-treated EB cells and promotes the proliferation of nestin-immunopositive cells, i.e., embryonic stem (ES)-derived neural stem-like cells. 相似文献
Case-carburizing of helical gears with large helix angles may form too large hardened layers near the tooth width end on the acute angle side (ACUTE-END), and adversely affect the bending fatigue strength. We investigated the bending fatigue strength of casecarburized helical gears with large helix angles up to approximately 40° through a bending fatigue test, hardness test, and residual stress measurement. We found that the case-carburizing formed large hardened layers near ACUTE-END, reduced the compressive residual stress near ACUTE-END, and restricted the improvement of the bending fatigue strength in a meshing state where tooth root stress became large near ACUTE-END. Based on the obtained bending fatigue limits, we revealed that ISO 6336-3:2006 overestimated the rate of increase of the permissible circumferential loads for helix angles exceeding approximately 30°, and ISO/DIS 6336-3:2018 underestimated this rate for helix angles near 30°.
Modeling an embankment by subjecting it to different upstream conditions in a centrifuge is challenging. However, the response of an embankment to shaking under different upstream conditions needs to be studied to ensure that the necessary precautions are taken during its construction and maintenance. Herein, the influence of different upstream conditions and embankment densities are investigated. The pore water pressure values at different locations in an embankment were recorded during seepage and under induced shaking. Accelerometers recorded the response of the embankment to shaking, and a linear variable differential transformer (LVDT) measured the settlement at the top of the embankment as a result of the shaking. An image analysis was used to trace the resulting deformation of the embankment due to the shaking. The results indicate that the upstream conditions of the embankment determine the failure mechanism of the embankment in cases of lower density. In addition, the distribution of the water content within the embankment was found to have a greater influence on its response to shaking than the water level height on its upstream side. 相似文献