Mechanically strengthened new Hagi porcelain developed by controlling the chemical environment of iron

In order to enhance the mechanical strength of Hagi Porcelain (Hagiyaki), one of the oldest and famous potteries in Japan, new preparation condition was examined. Tempered Hagi porcelain, denominated as ‘Hagi Porcelain B’, was prepared with the Porcelain clay originating from Daido district, Yamaguchi Prefecture, Japan. Structural change of ‘Hagi Porcelain B’ was investigated by means of ⁵⁷Fe-Mössbauer spectroscopy, X-ray diffractometry (XRD) and three-point bending test. Mechanical strength of the ‘original Hagi Porcelain B’ was estimated to be 43.1 MPa by means of the three-point bending test, while much larger value of 104.5 MPa could be achieved when tempered by a chemical modification. Mössbauer spectrum of the ‘original Hagi porcelain B’ was composed of a paramagnetic doublet and a magnetic sextet due to Fe(III) of γ-Fe₂O₃(maghemite), while only one paramagnetic doublet due to to octahedral Fe(II)O₆ was observed for the ‘tempered Hagi Porcelain B’ with isomer shift and quadrupole splitting values of 1.13 and 2.15 mm s^?1, respectively. It is considered that the absence of magnetic phase causes an increase of the mechanical strength because the maghemite phase has a defect spinel structure. These results indicate that mechanical strength of the ‘Hagi porcelain B’ could be enhanced by controlling the sintering condition.     

Size-Selective Harvesting of Extracellular Vesicles for Strategic Analyses Towards Tumor Diagnoses

Extracellular vesicles (EV), typified by exosomes or microvesicles, are expected to be effective diagnostic markers for cancers. The sizes of the vesicles range from 20 to 1000 nm, but the size-dependent variations of the contents of EVs are still poorly understood. We succeeded in the size-selective harvesting of the vesicles by utilizing the molecular weight-dependent characteristics of a variety of polyethylene glycols (PEG) as precipitating reagents and analyzed the antigens displayed on the surfaces of the vesicles and the miRNAs included in the vesicles from each size group. As a result, the relatively larger (<100 nm) particles precipitated by PEG5k clearly exhibited the greatest amount of epithelial cell adhesion molecule (EpCAM), from both breast cancer (MCF-7) and colon cancer (HCT116) cells, and a larger quantity of microRNA (miRNA) specific to breast cancer cells (miRNA155 for MCF-7) seemed to be contained in the PEG-precipitated particles. The results demonstrated that the quantities of both the tumor-specific miRNA and protein were similarly distributed among the several classes of the size-sorted EVs and that the size-selective harvesting of EVs may be informative for strategic analyses towards the diagnoses of cancers.     

Laser absorption-scattering technique applied to asymmetric evaporating fuel sprays for simultaneous measurement of vapor/liquid mass distributions

This paper describes an Ultraviolet-Visible Laser Absorption-Scattering (UV-Vis LAS) imaging technique applied to asymmetric fuel sprays. Continuing from the previous studies, the detailed measurement principle was derived. It is demonstrated that, by means of this technique, cumulative masses and mass distributions of vapor/liquid phases can be quantitatively measured no matter what shape the spray is. A systematic uncertainty analysis was performed, and the measurement accuracy was also verified through a series of experiments on the completely vaporized fuel spray. The results show that the Molar Absorption Coefficient (MAC) of the test fuel, which is typically pressure and temperature dependent, is the major error source. The measurement error in the vapor determination has been shown to be approximately 18% under the assumption of constant MAC of the test fuel. Two application examples of the extended LAS technique were presented for exploring the dynamics and physical insight of the evaporating fuel sprays: diesel sprays injected by group-hole nozzles and gasoline sprays impinging on an inclined wall.     

Synthesis of Unsaturated Nitriles from Trisubstituted Olefins Via Ene-Type Chlorination

Unsaturated nitriles have been synthesized from trisubstituted olefins via ene-type chlorination and regioselective substitution with cyanide ion followed by double bond migration.     

A novel condition for capillary electrophoretic analysis of reductively aminated saccharides without removal of excess reagents

We have identified novel CE conditions for the separation of 7‐amino‐4‐methylcoumarin‐labeled monosaccharides and oligosaccharides from glycoproteins. Using a neutrally coated capillary and alkaline borate buffer containing hydroxypropylcellulose and ACN, saccharide derivatives form anionic borate complexes, which move from the cathode to the anode in an electric field and are detected near the anodic end. Excess labeling reagents and other fluorescent products remain at the cathodic end. Fluorimetric detection using an LED as a light source enables determination of monosaccharide derivatives with good linearity between at least 0.4 and 400 μM, may correspond to 140 amol to 140 fmol. The lower LOD (S/N = 5) is only 80 nM in the sample solution (ca. 28 amol). The results were comparable to reported values using fluorometric detection LC. The method was also applied to the analysis of oligosaccharides that were enzymatically released from glycoproteins. Fine resolution enables profiling of glycans in glycoproteins. The applicability of the method was examined by applying it to other derivatives labeled with nonacidic tags such as ethyl p‐aminobenzoate‐ and 2‐aminoacridone‐labeled saccharides.     

Determination of zinc in marine/lacustrine sediments by graphite furnace atomic absorption spectrometry using Pd/Mg chemical modifier and slurry sampling

Effectiveness of Pd/Mg chemical modifier for the accurate direct determination of zinc in marine/lacustrine sediments by graphite furnace atomic absorption spectrometry (GF-AAS) using slurry samples was evaluated. A calibration curve prepared by aqueous zinc standard solution with addition of Pd/Mg chemical modifier is used to determine the zinc concentration in the sediment. The accuracy of the proposed method was confirmed using Certified Reference Materials, NMIJ CRM 7303-a (lacustrine sediment) from National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Japan, and MESS-3 (marine sediment) and PACS-2 (marine sediment) from National Research Council, Canada. The analytical results obtained by employing Pd/Mg modifier are in good agreement with the certified values of all the reference sediment materials. Although for NRC MESS-3 an accurate determination of zinc is achieved even without the chemical modifier, the use of Pd/Mg chemical modifier is recommended as it leads to establishment of a reliable and accurate direct analytical method. One quantitative analysis takes less than 15 minutes after we obtain dried sediment samples, which is several tens of times faster than conventional analytical methods using acid digested sample solutions. The detection limits are 0.13?µg?g^?1 (213.9?nm) and 16?µg?g^?1 (307.6?nm), respectively, in sediment samples, when 40?mg of dried powdered samples are suspended in 20?mL of 0.1?mol?L^?1 nitric acid and a 10?µl portion of the slurry sample is measured. The precision of the proposed method is 8–15% (RSD).     

An Unusual Cyclic System: Derivatives of N-Acetyl [2-Deoxy-β-D-Mannopyranosid]Urono-6,2-Lactam

ABSTRACT

Syntheses are described of a new ring system, namely derivatives of N-acetyl [2-deoxy-β-D-mannopyranosid]urono-6,2-lactam. These were formed by participation of a 2-acetamido-2-deoxy group in the oxidation using pyridinium dichromate of a 6-hydroxyl group in a mannopyranosidic system The structures of the new compounds were determined mainly by NMR experiments inter alia by HMBC techniques.     

57Fe-Mössbauer study of electrically conductive alkaline iron vanadate glasses

A relationship between local structure, thermal stability and electrical conductivity (σ) of xR₂O·10Fe₂O₃·(90 ? x)V₂O₅ glasses (abbreviated as xRFV glasses, where R = Li, Na, K; x = 20 and 40 in mol %) was investigated by ⁵⁷Fe-Mössbauer spectroscopy, X-ray diffractometry, differential thermal analysis (DTA) and DC two- and four-probe method. From DTA study, thermal stability of 20RFV glasses is lower than that of 40RFV glasses by evaluating Hruby parameter (K _gl). Constant activation energy for crystallization (E _a) of 2.5 eV obtained from both 20RFV and 40RFV glasses indicate that the crystallization proceeds with the cleavage of Fe–O bond having the energy of 2.6 eV. Isochronally annealed 20RFV glass at 400–450 °C resulted in the increase in electrical conductivity (σ) from the order of 10^?3 to 10^?1 S cm^?1, whereas slight decrease in σ was observed for 20RFV glass annealed above 460 °C. A paramagnetic doublet with an identical isomer shift (δ) of 0.39 mm s^?1 was observed in the ⁵⁷Fe-Mössbauer spectra of 20RFV glass after isothermal annealing conducted at 400–450 °C for 100 min, which caused a decrease of quadruple splitting (Δ) from 0.67 to 0.52 mm s^?1 for 20LiFV glass and from 0.66 to 0.53 mm s^?1 for 20NaFV glass. On the other hand, three paramagnetic doublets with δ and Δ of 0.40 and 0.25, 0.38 and 0.60, and 0.31 and 1.11 mm s^?1 respectively were observed for 20RFV glass annealed at 460–550 °C, reflecting precipitation of semiconducting FeVO₄ phase having σ of 6.0 × 10^?7 S cm^?1. It can be concluded that isochronal annealing of 20RFV glass below 450 °C resulted in increase in σ due to the structural relaxation, while annealing above 500 °C resulted in the decrease of σ due to the precipitation of FeVO₄ phase.