Degradation of fish gelatin using hot-compressed water and the properties of the degradation products

The degradation of fish gelatin using hot-compressed water was investigated. The hot-compressed water treatment resulted in the degradation of fish gelatin into peptides, and the number of the peptides increased with increasing the temperature. The distribution of amino acids in the product mixture indicated that hot-compressed water treatment at 240°C resulted in a high level of amino acid degradation, and the highest concentrations of free amino acids was at 220°C. Lysinoalanine, which is toxic, was rarely generated by hot-compressed water treatment at higher temperature range. Additionally, the optimum temperature for the hot-compressed water treatment with respect to the angiotensin I-converting enzyme inhibitory was at 180°C. These analyses demonstrate that the degradation of fish gelatin with hot-compressed water could be used to generate functional materials.     

Gas Chromatography–Mass Spectrometry of Bisphenol A Adducts with Propylene Oxide

Gas chromatography/resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS) was applied to the measurement of a sample of raw material, the main component of which was bisphenol A di(2-hydroxypropyl) ether, which is a bisphenol A propylene oxide 2 mol adduct (BPA-2PO). Consequently, the peak for the main component could be ionized and detected via ultraviolet laser pulse. Moreover, other components that were considered to be byproducts were also detected: an isomer of the main component along with bisphenol A propylene oxide 1 mol adduct and 3 mol adduct (BPA-1PO and BPA-3PO). In GC/REMPI-TOFMS, an intense molecular ion peak was obtained and soft ionization was achieved for all bisphenol A adducts with propylene oxide, compared with a conventional GC–MS coupled with electron ionization (EI). Based on the results of the GC/REMPI-TOFMS, the ratio of the peak area of the molecular ions of BPA-3PO against that of BPA-2PO was calculated to be 14 %.

     

Dispersion polymerization using hydroxy‐functional macroazoinitiators as an inistab

Hydroxy‐functional macroazoinitiators with central azo unit have been synthesized by atom transfer radical polymerization of 2‐hydroxyethyl methacrylate or 2‐hydroxypropyl methacrylate in methanol. The mean degrees of polymerization of the polymer chains beside the azo group were fixed at 30 and 60. Proton nuclear magnetic resonance (¹H NMR) and gel permeation chromatography were used to characterize the macroazoinitiators in terms of their chemical structure, molecular weight, and polydispersity, respectively. Dispersion polymerizations of styrene using the hydroxy‐functional macroazoinitiators as an inistab (initiator + colloidal stabilizer) in 2‐propanol or 2‐propanol/water media resulted in submicrometer‐sized polystyrene latex particles with hydroxy‐functional polymer hair. Electron microscopies, Fourier transform infrared spectrometer, thin layer chromatography, and ¹H NMR were used to characterize the particles in terms of their morphologies, particle sizes, and their distributions and chemical compositions. The synthesized particles behaved as an effective particulate emulsifier for the stabilization of oil‐in‐water emulsions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Quantification of phosphorus in DNA using capillary electrophoresis hyphenated with inductively coupled plasma mass spectrometry

We have analyzed phosphorus in an enzymatically digested DNA molecule using capillary electrophoresis (CE) hyphenated with inductively coupled plasma mass spectrometry (ICP-MS). The DNA concentration was quantified by the phosphorus value obtained in the CE-ICP-MS analysis. The CE-ICP-MS measurement, for which the interface device AIF-01 equipped three layered nebulizer was adopted, was achieved with limited μL/min nebulizing without loss of sample in the vaporizing chamber. The samples of nucleotides and free phosphate were separated well in the CE-ICP-MS measurement, and the calibration curve (0.1-10μg/mL) of the phosphorus showed a linear (R(2)=0.999) increase in intensity. After digestion of the 100-bp double-strand DNA sample to deoxyribonucleotide-5'-monophosphates (dNMPs) by phosphodiesterase-I, phosphorus was detected by CE-ICP-MS without further purification steps. In this study, we applied two calculation schemes of DNA analysis using a dNMP concentration obtained from CE-ICP-MS. Comparative CE-ICP-MS analysis with DNA digested to dNMPs showed that the assay gave an equal value obtained from the total DNA quantification using fluorescence detection. The detection limits of the DNA sample obtained from these species and phosphorus in nucleotides using CE-ICP-MS were 3.1-26ng/mL. These LOD values were equal to the conventional fluorescence determination of DNA.     

Synthesis of 2-substituted quinones, vitamin K3, and vitamin K1 from p-cresol. BF3·OEt2-catalyzed methyl migration of 4-tert-butyldioxycyclohexadienones

BF₃·OEt₂-catalyzed methyl group migration of 4-methyl-4-tert-butyldioxycyclohexadienone, which is obtained by ruthenium-catalyzed oxidation of p-cresol with tert-butyl hydroperoxide, in hexafluoro-2-propanol/toluene gave toluquinone efficiently. The reaction can be applied to the regio-selective short-step syntheses of vitamin K₃ and vitamin K₁ from p-cresol.     

Evaluating 3D position and velocity of subject in parabolic flight experiment by use of the binocular stereo vision measurement

<正>A practical method for evaluating the three-dimensional(3D) position and velocity of a moving object used in the parabolic flight experiment is developed by using the binocular stereo vision measurement theory. The camera calibration mathematic model without considering the lens distortion is introduced.The direct linear transformation(DLT) algorithm is improved to accomplish the camera calibration.The camera calibration result and optimization algorithm are used to calculate the object's world coordinate from image coordinate.The 3D position and the velocity of the moving object are obtained.The standard uncertainty in estimating the velocity is 0.0024 m/s,which corresponds to 1%level of the velocity of the object in the experiment.The results show that this method is very useful for the parabolic flight experiments.     

Performance of the micro‐PIC gaseous area detector in small‐angle X‐ray scattering experiments

The application of a two‐dimensional photon‐counting detector based on a micro‐pixel gas chamber (µ‐PIC) to high‐resolution small‐angle X‐ray scattering (SAXS), and its performance, are reported. The µ‐PIC is a micro‐pattern gaseous detector fabricated by printed circuit board technology. This article describes the performance of the µ‐PIC in SAXS experiments at SPring‐8. A dynamic range of >10⁵ was obtained for X‐ray scattering from a polystyrene sphere solution. A maximum counting rate of up to 5 MHz was observed with good linearity and without saturation. For a diffraction pattern of collagen, weak peaks were observed in the high‐angle region in one accumulation of photons.     

Preparation of Nb doped PZT film by RF sputtering

Undoped lead zirconate titanate (PZT) and Nb doped lead zirconate titanate (PNZT) films formed on an Ir/Ti/SiO₂/Si substrate using an RF magnetron sputtering method were studied in detail. Films of about 3–4 μm thickness were deposited at a substrate temperature of 525 ^°C. X-ray diffraction measurement (XRD) shows that the obtained PZT and PNZT films are both strongly uniaxially oriented in the (100) direction of the perovskite structure, and TEM observation shows that the films have columnar structures. The addition of Nb results in changes of film electrical characteristics, particularly dielectric constant and hysteresis characteristics. Sputtered PNZT films (Nb 13 at.%) formed on silicon diaphragm structures generate 2 times more deflections than undoped PZT film formed on the same structure, thus demonstrating a superior piezoelectric performance. A sputtering method to directly form a PNZT film with high piezoelectric constant on a substrate at low temperature via electrodes finds a wide potential use in MEMS applications.     

Long-range structural order, moiré patterns, and iridescence in latex-stabilized foams

We describe the facile production of highly stable foams stabilized solely by micrometer-sized, sterically stabilized polystyrene (PS) latex particles. Such foams can survive for more than one year in the wet state and remain intact after drying. In contrast, foams stabilized with either sodium dodecyl sulfate or poly(N-vinylpyrrolidone) were destroyed after removal of the aqueous phase. Scanning electron microscopy studies reveal hexagonally close-packed arrays of PS particles within the dried foam, which suggests high colloid stability for the PS particles prior to their adsorption at the air-water interface. Localized moiré patterns are observed by optical microscopy due to the formation of well-defined latex bilayers with exquisite long-range order. Moreover, the dried foams are highly iridescent in bright transmitted light, which may offer potential applications in security inks and coatings.     

Trigonal-bipyramidal geometry induced by an external water ligand in a sterically hindered iron salen complex, related to the active site of protocatechuate 3,4-dioxygenase

A unique distorted trigonal-bipyramidal geometry observed for the non-heme iron center in protocatechuate 3,4-dioxygenase (3,4-PCD) was carefully examined utilizing a sterically hindered iron salen complex, which well reproduces the endogenous His2Tyr2 donor set with water as an external ligand. X-ray crystal structures of a series of iron model complexes containing bis(3,5-dimesitylsalicylidene)-1,2-dimesitylethylenediamine indicate that a distorted trigonal-bipyramidal geometry is achieved upon binding of water as an external ligand. The extent of a structural change of the iron center from a preferred square-pyramidal to a distorted trigonal-bipyramidal geometry varies with the external ligand that is bound in the order Cl < EtO < H2O, which is consistent with the spectrochemical series. The distortion in the model system is not due to steric repulsions but electronic interactions between the external ligand and the iron center, as evidenced from the X-ray crystal structures of another series of iron model complexes with a less-hindered bis(3-xylylsalicylidene)-1,2-dimesitylethylenediamine ligand, as well as by density functional theory calculations. Further spectroscopic investigations indicate that a unique distorted trigonal-bipyramidal geometry is indeed maintained even in solution. The present model study provides a new viewpoint that a unique distorted trigonal-bipyramidal iron site might not be preorganized by a 3,4-PCD protein but could be electronically induced upon the binding of an external hydroxide ligand to the iron(III) center. The structural change induced by the external water ligand is also discussed in relation to the reaction mechanism of 3,4-PCD.