Methylamine stimulates the action of ricin toxin but inhibits that of diphtheria toxin

The action of ricin toxin was stimulated by addition of methylamine or some other amines, as shown by measuring the inhibition of protein synthesis of cultured cells by the toxin. Under the same conditions, however, the action of diphtheria toxin was completely inhibited by the amines. In a cell-free protein-synthesizing system, methylamine had no effect on the action of the A chain of ricin toxin and fragment A of diphtheria toxin. Studies on the interactions of 125I-labeled toxins with cells revealed that methylamine did not alter toxin-receptor bindings, but affected the entry of the toxins into the cells. Studies were also made on the effects of methylamine on the actions of two hybrid toxins, formed from a subunit of Wistaria floribunda lectin and fragment A of diphtheria toxin and the A chain of ricin toxin, respectively. Results suggested that the processes of entry of ricin toxin and diphtheria toxin, or at least parts of these processes, are different.     

Diphtheria toxin binds to the epidermal growth factor (EGF)-like domain of human heparin-binding EGF-like growth factor/diphtheria toxin receptor and inhibits specifically its mitogenic activity

The membrane anchored form of human heparin-binding epidermal growth factor-like growth factor (HB-EGF) acts as the diphtheria toxin (DT) receptor. Transfection of human HB-EGF cDNA into mouse LC cells, L cells stably expressing DRAP27, conferred sensitivity to DT, but transfection of mouse HB-EGF cDNA did not. To define the essential regions of HB-EGF that serve as the functional DT receptor, we examined the sensitivity to DT and DT binding of cells expressing several human/mouse HB-EGF chimeras. It was found that DT binds to the EGF-like domain of the human HB-EGF. However, mouse HB-EGF does not serve as a functional DT receptor due to non-conserved amino acid substitutions in this domain. In addition, CRM197, a non-toxic mutant of DT, inhibited strongly the mitogenic activity of the secreted form of human HB-EGF, but not of mouse HB-EGF and other EGF receptor-binding growth factors. These results confirmed further that DT interacts with the EGF-like domain of HB-EGF and that this interaction is specific for human HB-EGF.     

Chemical Removal of CeO2 Segregated on the Surface of CeO2–ZrO2 Binary Oxides for Improvement of OSC

A chemical treatment to remove residual CeO₂ phase on CeO₂–ZrO₂ (CZ) solid solution was carried out. A CZ was treated by H₂O₂ for the reduction of Ce⁴⁺ to Ce³⁺ and then HNO₃ for the dissolution of Ce³⁺ compounds (H–CZ). H₂-TPR, TEM-EDX and XPS analyses revealed the removal of CeO₂ phase and the homogeneous distribution of Ce species. About 20% improvement in oxygen storage capacity (OSC) of H–CZ was confirmed at 773 K by the weight measurements under H₂/N₂ and air atmospheres, indicating that the HNO₃/H₂O₂ treatment was effective to avoid the deterioration of the OSC by segregated CeO₂ on the CZ binary oxides.     

Low Frictional Coating of Copper Oxide with Preferred Crystal Orientation

Coating films of copper oxide were synthesized on stainless steel substrates with a r.f. magnetron sputter. The composition of the films could be controlled by changing a gas ratio of oxygen and argon in sputter plasma, which was analyzed with X-ray diffraction spectroscopy. Frictional property of the films in an atmospheric pressure and in an ultra high vacuum (UHV) was measured with a pin-on-disk vacuum tribometer. Frictional coefficients of the film as low as 0.03 and 0.05 were achieved in an atmospheric pressure and in UHV, respectively. It is therefore, expected that the films are applicable to smooth-drive movable materials for ultimate conditions such as UHV and high temperature.     

Polarization independent, linear-tuned interference filter with constant transmission characteristics over 1530-1570-nm tuning range

We present a polarization independent optical tunable filter (OTF) with nearly constant transmission characteristics over 1530-1570 nm. The tuning is achieved by horizontally sliding an interference filter, resulting in a very low polarization dependent loss (PDL)<0.1 dB and nearly constant characteristics over the tuning range. By cascading interference filters in double or triple stage, narrower bandwidth characteristics are obtained allowing for smaller channel spacing in wavelength division multiplexing (WDM) systems. Experimental results for PDL, loss, and bandwidth are presented and compared to those of angle-tuned filter. The proposed OTF has shown superior performance promising a practical solution for dense WDM applications.     

Recognition of camera-captured low-quality characters using motion blur information

Camera-based character recognition has gained attention with the growing use of camera-equipped portable devices. One of the most challenging problems in recognizing characters with hand-held cameras is that captured images undergo motion blur due to the vibration of the hand. Since it is difficult to remove the motion blur from small characters via image restoration, we propose a recognition method without de-blurring. The proposed method includes a generative learning method in the training step to simulate blurred images by controlling blur parameters. The method consists of two steps. The first step recognizes the blurred characters based on the subspace method, and the second one reclassifies structurally similar characters using blur parameters estimated from the camera motion. We have experimentally proved that the effective use of motion blur improves the recognition accuracy of camera-captured characters.     

Determination of nequinate and buquinolate in livestock products using liquid chromatography-tandem mass spectrometry

We studied the simultaneous determination of nequinate and buquinolate, which are used as feed additives to prevent coccidiosis, by means of liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile, then loaded onto an HLB mini-column with 20% methanol. After clean-up with 20% methanol, the analytes were eluted with acetonitrile-methanol (1 : 1). The coccidiostats in the purified samples were determined using ESI-MRM mode LC-MS/MS with a sample matrix calibration curve. Mean recoveries of nequinate and buquinolate from 8 kinds of livestocks samples (chicken muscle, chicken liver, chicken heart, swine muscle, swine heart, cattle muscle, sheep muscle, egg) were in the range of 89.5% to 108.6%, and the relative standard deviation values were <20% (n=10) at the levels of 0.01 μg/g and 0.05 μg/g, respectively. The limits of quantification of these compounds were 0.001 μg/g in each sample.     

析出相对Cr-Mn-N奥氏体不锈钢应力腐蚀性能的影响

本文研究了合金碳化物M_(23)C_6和金属间化合物x相对Cr-Mn-N奥氏体不锈钢应力腐蚀性能的影响。结果指出,在4NNaCl溶液中,上述两种沉淀相对钢的自然腐蚀电位和不同电位下的断裂时间影响明显,而在45％MgCl_2溶液中,两种沉淀相的影响甚微。从断裂机制上对两种沉淀相的影响进行了讨论。     

Fabrication of a simultaneous red-green-blue reflector using single-pitched cholesteric liquid crystals

A cholesteric liquid crystal (CLC) is a self-assembled photonic crystal formed by rodlike molecules, including chiral molecules, that arrange themselves in a helical fashion. The CLC has a single photonic bandgap and an associated one-colour reflection band for circularly polarized light with the same handedness as the CLC helix (selective reflection). These optical characteristics, particularly the circular polarization of the reflected light, are attractive for applications in reflective colour displays without using a backlight, for use as polarizers or colour filters and for mirrorless lasing. Recently, we showed by numerical simulation that simultaneous multicolour reflection is possible by introducing fibonaccian phase defects. Here, we design and fabricate a CLC system consisting of thin isotropic films and of polymeric CLC films, and demonstrate experimentally simultaneous red, green and blue reflections (multiple photonic bandgaps) using the single-pitched polymeric CLC films. The experimental reflection spectra are well simulated by calculations. The presented system can extend applications of CLCs to a wide-band region and could give rise to new photonic devices, in which white or multicolour light is manipulated.     

A highly sensitive method for quantifying gallocatechin gallate and its epimer using a catechin-specific peptide

We have developed a method for quantifying gallocatechin gallate (GCg) and epigallocatechin gallate (EGCg) using a catechin-binding peptide (part of the 67-kDa laminin receptor). Using micro titer plates, we investigated various conditions, including the quantifiable range of EGCg concentrations, the optimal concentration of the catechin-binding peptide, and the optimal reaction conditions. In this microplate assay, after each well was coated with bovine serum albumin, sample containing GCg and EGCg was added at pH 8.0, and allowed to stand at 37 °C for 2 h. After washing, biotinylated-peptide solution was added at 1 μg mL^?1 and allowed to react for 1 h at 37 °C. Each well was added with streptavidin–horseradish peroxidase conjugate, followed by chromogenic reaction for 25 min at room temperature. After the reaction, absorbance was measured at 405 nm. Our method is capable of quantifying EGCg in the range of approximately 0.1–2.0 mg L^?1 with a high degree of sensitivity and a high correlation (R² = 0.98) between EGCg concentration and absorbance. The method was specific to GCg and EGCg and seems capable of estimating GCg and EGCg contents in the presence of other catechin compounds. The method is simple and highly sensitive for quantitative GCg and EGCg measurement that requires no special equipment or operation and can measure multiple samples simultaneously.