Intergrowth between the Oxynitride Perovskite SrTaO2N and the Ruddlesden-Popper Phase Sr2TaO3N.

Strontium tantalum oxynitrides were prepared within the nominal composition range of 1.0 ≤ x ≤ 2.0, where x = Sr/Ta atomic ratio. A gradual structural transition was observed between the perovskite SrTaO2N and the Ruddlesden-Popper phase Sr2TaO3N with increasing SrO content. X-ray diffraction analyses showed that a single-phase perovskite was obtained up to x = 1.1, after which Sr2TaO3N gradually appeared at x ≥ 1.25. High-resolution scanning transmission electron microscopy observations identified the gradual intergrowth of a Ruddlesden-Popper Sr2TaO3N type planar structure interwoven with the perovskite crystal lattice upon increasing x. The crystal lattice at x = 1.4 was highly defective and consisted primarily of perovskite intergrown with a large amount of the Ruddlesden-Popper phase structure. This Ruddlesden-Popper phase layer intergrowth is a characteristic of an oxynitride perovskite rather than the Ruddlesden-Popper defects previously reported in oxide perovskites. Partial substitution of Ta with Sr was also evident in this perovskite lattice. Just below x = 2, a perovskite-type structure was intergrown as defects in the Ruddlesden-Popper Sr2TaO3N. Characterization of Sr2TaO3N in ambient air was challenging due to its moisture sensitivity. Thermal analysis demonstrated that this material was relatively stable up to approximately 1400 °C in comparison with SrTaO2N perovskite, especially under nitrogen. Sr2TaO3N could keep its structure in a sealed tube, and some amount of SrCO3 was observed in XRD after 10 days of exposure to 75% relative humidity under prior ambient conditions. A compact of this material had a relative density of 96% after sintering at 1400 °C under 0.2 MPa of nitrogen, even though a drastic loss of nitrogen was previously reported for a SrTaO2N perovskite under these same conditions. Postammonolysis of the Sr2TaO3N ceramics was not required prior to studying its dielectric behavior. This is in contrast to the SrTaO2N perovskite, which requires postammonolysis to recover its stoichiometric composition and electrical insulating properties.

Alternative Internal Standard Calibration of an Indirect Enzymatic Analytical Method for 2-MCPD Fatty Acid Esters.

An indirect enzymatic analysis method for the quantification of fatty acid esters of 2-/3-monochloro-1,2-propanediol (2/3-MCPD) and glycidol was developed, using the deuterated internal standard of each free-form component. A statistical method for calibration and quantification of 2-MCPD-d5, which is difficult to obtain, is substituted by 3-MCPD-d5 used for calculation of 3-MCPD. Using data from a previous collaborative study, the current method for the determination of 2-MCPD content using 2-MCPD-d5 was compared to three alternative new methods using 3-MCPD-d5. The regression analysis showed that the alternative methods were unbiased compared to the current method. The relative standard deviation (RSDR) among the testing laboratories was ≤ 15% and the Horwitz ratio was ≤ 1.0, a satisfactory value.

Collaborative Study of an Indirect Enzymatic Method for the Simultaneous Analysis of 3-MCPD, 2-MCPD, and Glycidyl Esters in Edible Oils.

A collaborative study was conducted to evaluate an indirect enzymatic method for the analysis of fatty acid esters of 3-monochloro-1,2-propanediol (3-MCPD), 2-monochloro-1,3-propanediol (2-MCPD), and glycidol (Gly) in edible oils and fats. The method is characterized by the use of Candida rugosa lipase, which hydrolyzes the esters at room temperature in 30 min. Hydrolysis and bromination steps convert esters of 3-MCPD, 2-MCPD, and glycidol to free 3-MCPD, 2-MCPD, and 3-monobromo-1,2-propanediol, respectively, which are then derivatized with phenylboronic acid, and analyzed by gas chromatography-mass spectrometry. In a collaborative study involving 13 laboratories, liquid palm, solid palm, rapeseed, and rice bran oils spiked with 0.5-4.4 mg/kg of esters of 3-MCPD, 2-MCPD, and Gly were analyzed in duplicate. The repeatability (RSDr) were < 5% for five liquid oil samples and 8% for a solid oil sample. The reproducibility (RSDR) ranged from 5% to 18% for all oil samples. These RSDR values were considered satisfactory because the Horwitz ratios were ≤ 1.3% for all three analytes in all oil samples. This method is applicable to the quantification of 3-MCPD, 2-MCPD, and Gly esters in edible oils.

Optimization of an Indirect Enzymatic Method for the Simultaneous Analysis of 3-MCPD, 2-MCPD, and Glycidyl Esters in Edible Oils.

We developed a novel, indirect enzymatic method for the analysis of fatty acid esters of 3-monochloro-1,2-propanediol (3-MCPD), 2-monochloro-1,3-propanediol (2-MCPD), and glycidol (Gly) in edible oils and fats. Using this method, the ester analytes were rapidly cleavaged by Candida rugosa lipase at room temperature for 0.5 h. As a result of the simultaneous hydrolysis and bromination steps, 3-MCPD esters, 2-MCPD esters, and glycidyl esters were converted to free 3-MCPD, 2-MCPD, and 3-monobromo-1,2-propanediol (3-MBPD), respectively. After the addition of internal standards, the mixtures were washed with hexane, derivatized with phenylboronic acid, and analyzed by gas chromatography-mass spectrometer (GC-MS). The analytical method was evaluated in preliminary and feasibility studies performed by 13 laboratories. The preliminary study from 4 laboratories showed the reproducibility (RSD R ) of < 10% and recoveries in the range of 102-111% for the spiked 3-MCPD and 2-MCPD in extra virgin olive (EVO) oil, semi-solid palm oil, and solid palm oil. However, the RSDR and recoveries of Gly in the palm oil samples were not satisfactory. The Gly content of refrigerated palm oil samples decreased whereas the samples at room temperature were stable for three months, and this may be due to the depletion of Gly during cold storage. The feasibility studies performed by all 13 laboratories were conducted based on modifications of the shaking conditions for ester cleavage, the conditions of Gly bromination, and the removal of gel formed by residual lipase. Satisfactory RSDR were obtained for EVO oil samples spiked with standard esters (4.4% for 3-MCPD, 11.2% for 2-MCPD, and 6.6% for Gly).

Identification and evaluation of anti-inflammatory compounds from Kaempferia parviflora.

The rhizome of Kaempferia parviflora has been used in traditional Thai medicine. In this study, we identified and compared specific compounds from the hexane extract of K. parviflora with those from other Zingiberaceous plants by using gas chromatography-mass spectrometry. We identified 5,7-dimethoxyflavone (DMF), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (TMF), estimated 3,5,7-trimethoxyflavone, 5-hydroxy-7,4'-dimethoxyflavone, 3,5,7,4'-tetramethoxyflavone, and investigated their anti-inflammatory effects in rat basophilic leukemia (RBL-2H3) cells stimulated with an IgE antigen or a calcium ionophore. We found that DMF and TMF more potently inhibited antigen-induced degranulation than did nobiletin, a well-known anti-inflammatory agent. In addition, compared to RBL-2H3 cells stimulated with a calcium ionophore, those treated with DMF and TMF showed more marked inhibition of the degranulation and the production and mRNA expression of inflammatory mediators. These results suggest that DMF and TMF inhibit an early step in the high-affinity IgE receptor signaling cascade rather than intracellular calcium release and protein kinase C activation.

Acrylamide in roasted barley grains: presence, correlation with colour and decrease during storage.

We investigated the presence of acrylamide in roasted barley grains, and assessed the correlation between acrylamide concentration and colour, and also examined acrylamide decrease during storage. Acrylamide concentrations in 45 commercially available roasted barley grains were analysed. The mean and standard deviation were 0.24 and 0.08 mg kg(-1), respectively. The CIE colour parameter a* value had little correlation with acrylamide concentration in roasted barley grains; however, the L* and b* values showed correlations with acrylamide concentration in the grains, yielding a correlation coefficient of 0.42 and 0.40, respectively. Darker-coloured roasted barley grains with lower L* values may contain lower amounts of acrylamide. Although acrylamide concentration decreased by 40% in the grains, and decreased by 36% in the milled grains (teabag form) after 309 days of storage at room temperature a significant difference in the rate of acrylamide decrease was not observed between the grain and teabag forms. The data obtained in this study are of importance to the risk assessment and management of acrylamide exposure in Japan.

Ionic liquid-induced formation of the α-helical structure of ß-lactoglobulin.

Structural modification of bovine milk ß-lactoglobulin (ß-LG) in aqueous 1-butyl-3-methylimidazolium nitrate ([bmim][NO3]) and ethylammonium nitrate ([EAN][NO3]) solutions has been investigated by Fourier transform infrared and circular dichroism spectroscopy. Remarkably, high ionic liquid (IL) concentrations (>15 mol %IL) caused formation of a non-native α-helical structure of ß-LG and disruption of its tertiary structure. Furthermore, while [bmim][NO3] promoted protein aggregation, [EAN][NO3] inhibited it probably owing to differences in the unique solution structure (nanoheterogeneity) of the ILs by the different cationic species. The IL-induced α-helical formation of ß-LG shows a behavior similar to the alcohol denaturation, but a disordered structure-rich state was observed in the ß-α transition process by adding IL, in contrast to the case of an aqueous alcohol solution of protein. We propose that the molten salt-like property of aqueous IL solutions strongly support α-helical formation of proteins.

High ionic liquid concentration-induced structural change of protein in aqueous solution: a case study of lysozyme.

The structural change of chicken egg white lysozyme in aqueous 1-butyl-3-methylimidazolium nitrate ([bmim][NO(3)]) solutions (0-24 M) has been investigated by optical spectroscopy and small-angle X-ray scattering (SAXS) methods. Fourier-transform infrared (FTIR) and circular dichroism (CD) spectra and SAXS profiles indicated that the addition of up to 6 M of [bmim][NO(3)] induces unfolding of lysozyme resulting from disruption of the α-helix by the NO(3)(-) ion. On the other hand, even with the addition of more than 10 M of [bmim][NO(3)], lysozyme aggregation is inhibited and the protein adopts a partially globular state (the secondary structure is partially refolded while the tertiary structure is disrupted). Observation of the structural features of the aqueous [bmim][NO(3)] solution by Raman OD stretching spectra indicated that bulk-like water still remains at concentrations above 10 M and form an "aggregated water" (water pool) in the nanoheterogeneous structure consisting of a polar domain (the high charge-density region) and nonpolar areas (the alkyl-chain region) in the IL. At these concentrations (above 10 M), lysozyme is not sufficiently hydrated because of the reduced number of water molecules. Consequently lysozyme above 10 M assumes the partially globular state. We propose that the changes of the unique IL solution structure (nanoheterogeneous) between the lower and higher [bmim][NO(3)] concentrations strongly correlated to the differences in the protein stability of the present results.

Monitoring of acrylamide concentrations in potato chips in Japan between 2006 and 2010.

Acrylamide levels in commercially available potato chips in Japan were monitored between August 2006 and June 2010 using the xanthydrol derivative gas chromatography-mass spectrometry (GC-MS) method. Seasonal and annual changes in acrylamide concentrations were determined. Nationwide bimonthly sampling of potato chips was carried out using a four-level design, and seasonal variations were detected in which the minimum acrylamide concentration was observed in August, and the maximum between February and June. Seasonal variations became less apparent after August 2008 as a result of annual effects and/or mitigation measures taken by the potato chip producers. Sampling uncertainties were separated into time-to-time, city-to-city, and lot-to-lot variation, and the largest variation was shown to be lot-to-lot including bag-to-bag.

A method for the determination of acrylamide in a broad variety of processed foods by GC-MS using xanthydrol derivatization.

A novel GC-MS method was developed for the determination of acrylamide, which is applicable to a variety of processed foods, including potato snacks, corn snacks, biscuits, instant noodles, coffee, soy sauces and miso (fermented soy bean paste). The method involves the derivatization of acrylamide with xanthydrol instead of a bromine compound. Isotopically labelled acrylamide (d3-acrylamide) was used as the internal standard. The aqueous extract from samples was purified using Sep-Pak™ C18 and Sep-Pak™ AC-2 columns. For amino acid-rich samples, such as miso or soy sauce, an Extrelut™ column was used for purification or extraction. After reaction with xanthydrol, the resultant N-xanthyl acrylamide was determined by GC-MS. The method was validated for various food matrices and showed good linearity, precision and trueness. The limit of detection and limit of quantification ranged 0.5-5 and 5-20 µg kg⁻¹), respectively. The developed method was applied as an exploratory survey of acrylamide in Japanese foods and the method was shown to be applicable for all samples tested.

Inactivation of avian influenza virus H1N1 by photocatalyst under visible light irradiation.

A novel photocatalyst - ILUMIO (platinum-loaded tungsten oxide) - was evaluated for its anti-influenza virus activity with the avian isolate A/northern pintail/Miyagi/1472/08 (H1N1). Under a fluorescent lamp of 1000lx in the absence of ultraviolet light, the virus was inactivated to below the detection limit i.e. >5.3log inactivation within 2h. This photocatalyst can be used for coating walls, tables, and other surfaces to decrease virus infectivity associated with surfaces. This would be desirable to reduce transmission of infection due to indirect contact, because self-inoculation of the nasal mucosa by contaminated hands is a major transmission mode of influenza viruses from human to human, alongside with transmissions via aerosols and droplets.