Effects of substrate misorientation on triple-period ordering in AlInAs

Substrate misorientation effects on triple-period (TP) ordering in Al_0.48In_0.52As were studied. When AlInAs was grown on a (001) InP substrate misoriented by 4° in the [ 1]A direction, TP-type ordering formed more strongly in the [ 1]A direction than in the [111]A direction. This asymmetric formation of TP-type ordering demonstrates that the step-arrays descending in the [ 0] direction play an important role in TP-type ordering formation in the [ 1]A direction. When AlInAs was grown at a higher temperature on a (001) InP substrate misoriented by 4° in the [ 11]B direction, CuPt-type ordering was formed more strongly in the [ 11]B than in the [1 1]B direction. The importance of the [ 10] step in CuPt-type ordering, which is well established in GaInP systems, was thus reconfirmed in this study on AlInAs.     

Highly polarized very cold neutrons through a permanent magnet quadrupole

We obtained highly polarized very cold neutrons through a quadrupole magnet with a large aperture. When neutrons go through a quadrupole magnet, parallel-spin neutrons are attracted to the magnet axis and anti-parallel-spin neutrons are repelled off the axis. Therefore, the neutrons through a sufficiently long quadrupole magnet have completely parallel-spin. At the downstream of the quadrupole magnet, we placed another quadrupole magnet to divide neutrons into two regions depending on their spin directions. We obtained the neutron polarization from the integrated count of the two regions and found it was 99.88±0.09 (stat.)±0.05 (syst.)%.     

Development of neutron spin phase contrast imaging

We present an imaging technique utilizing a neutron spin interferometer. Neutron spin phase contrast is achieved in spatial resolved measurements of the phase difference between two superposed neutron spin states introduced by passing through a magnetic sample. Since the phase difference of spin states parallel and anti-parallel to the magnetic field is proportional to the magnetic field integral, it is possible to record images of the internal magnetic field distribution of the sample. Taking advantage of high transmission probabilities, neutron spin phase contrast provides non-destructive images of internal magnetic structures.     

Cyclic tautomers of tryptamines and tryptophans. V. Formation and reactions of cyclic tautomers of cyclo-L-tryptophanyl-L-proline

Two stereoisomeric cyclic tautomers ($\text{5}$ and $\text{6}$ of cyclo-L-tryptophanyl-L-proline whose stereochemistry was established by x-ray analysis, gave 5- and 6-hydroxytryptophanyl derivatives ($\text{10}$), $\text{11}$, and $\text{19}$) on the hydroxylation with lead tetraacetate in trifluoroacetic acid.     

Autothermal reforming of biogas over a monolithic catalyst

This study focused on measurement of the autothermal reforming of biogas over a Ni based monolithic catalyst. The effects of the steam/CH₄ (S/C) ratio, O₂/CH₄ (O₂/C) ratio and temperature were investigated. The CH₄ conversions were higher under all examined temperatures than the equilibrium conversion calculated using the blank outlet temperature, because the catalyst layer was heated by the exothermic catalytic partial oxidation reaction. The CH₄ conversion increased with increasing O₂/C ratio. Moreover, the CH₄ conversion was higher than the equilibrium conversion calculated using the blank outlet temperature for O₂/C>0.42 and reached about 100% at O₂/C=0.55. However, the hydrogen concentration decreased for O₂/C>0.45 because hydrogen was combusted to steam in the presence of excess oxygen. On the other hand, the hydrogen and CO₂ concentrations increased and the CO concentration decreased with increasing S/C ratio. As a result, it was found that the highest hydrogen concentrations and CH₄ conversions were attained at the O₂/C ratios of 0.45-0.55 and the S/C ratios of 1.5-2.5. Moreover, the H₂/CO ratio could also be controlled in the range from about 2 to 3.5 to give at least 90% CH₄ conversion, by regulating the O₂/C or S/C ratios.     

Evolved gas analysis-mass spectrometry using skimmer interface and ion attachment mass spectrometry

Summary A new EGA-MS instrument consisted of a combination of skimmer interface with no change of evolved gaseous species and IAMS (Ion Attachment Mass Spectrometry) with no fragmentation during the ionization has been developed successfully. As its application of evolved gaseous species from PVA as firing process of alumina ceramics binder, the method has indicated detection of gaseous species which have not been detected with Py-GC-MS.     

Redispersible dry emulsion system as novel oral dosage form of oily drugs: in vivo studies in beagle dogs.

The absorption characteristics of vitamin E acetate (VEA) formulated into a dry emulsion system after its oral administration to beagle dogs were determined and compared to those of two different dosage forms (an oily mixture of the drug with cottonseed oil and an oil (drug)-in-water emulsion). The three dosage forms were administered in a crossover fashion to six nonfasting subjects, and the drug absorption was assessed from the plasma concentration of the major metabolite (free vitamin E). VEA formulated in the dry emulsion was rapidly absorbed, which suggested that a considerable amount was released as reformed emulsion droplets in the gastrointestinal tract as well as in water in vitro. Based on the analysis of variance, no significant differences in bioavailability parameters (AUC, Cmax or Tmax) were observed among the three dosage forms.     

Determination of acrolein in serum by high‐performance liquid chromatography with fluorescence detection after pre‐column fluorogenic derivatization using 1,2‐diamino‐4,5‐dimethoxybenzene

Acrolein is a major unsaturated aldehyde that is generated during the lipid peroxidation process. The measurement of acrolein in biological samples should be useful to estimate the degree of lipid peroxidation and to evaluate the effect of hazardous properties of acrolein on human health. In this study, a highly sensitive and selective high‐performance liquid chromatography with fluorescence detection method was developed for the determination of acrolein in human serum. The proposed method involves the pre‐column fluorogenic derivatization of acrolein with 1,2‐diamino‐4,5‐dimethoxybenzene (DDB) as a reagent. The fluorescent derivative of acrolein could be detected clearly without any interfering reagent blank peaks because DDB does not have intrinsic fluorescence itself, and the detection limit was 10 nM (signal‐to‐noise ratio = 3). The proposed method could selectively detect acrolein in human serum with a simple protein precipitation treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

Determination of avoparcin in animal tissues and milk using LC‐ESI‐MS/MS and tandem‐SPE

A highly sensitive and selective method using LC‐ESI‐MS/MS and tandem‐SPE was developed to detect trace amounts of avoparcin (AV) antibiotics in animal tissues and milk. Data acquisition using MS/MS was achieved by applying multiple reaction monitoring of the product ions of [M + 3H]³⁺ and the major product ions of AV‐α and ‐β at m/z 637 → 86/113/130 and m/z 649 → 86/113/130 in ESI(+) mode. The calculated instrumental LODs were 3 ng/mL. The sample preparation was described that the extraction using 5% TFA and the tandem‐SPE with an ion‐exchange (SAX) and InertSep C18‐A cartridge clean‐up enable us to determine AV in samples. Ion suppression was decreased by concentration rates of each sample solution. These SPE concentration levels could be used to detect quantities of 5 ppb (milk), 10 ppb (beef), and 25 ppb (chicken muscle and liver). The matrix matching calibration graphs obtained for both AV‐α (r >0.996) and ‐β (r >0.998) from animal tissues and milk were linear over the calibration ranges. AV recovery from samples was higher than 73.3% and the RSD was less than 12.0% (n = 5).     

Structure and Surface Properties of High-density Polyelectrolyte Brushes at the Interface of Aqueous Solution

Zwitterionic and cationic polyelectrolyte brushes were prepared by surface-initiated atom transfer radical polymerization of 2-methacryloyloxy- ethyl phosphorylcholine (MPC) and 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA), respectively. The poly(DMAEMA) brush was treated with methyl iodide to form poly[2-(methacryloyloxy) ethyltrimethylammonium iodide] [poly(METAI)]. The effects of ionic strength on brush structure and surface properties of densely grafted polyelectrolyte brushes were analyzed by contact angle measurements, neutron reflectivity (NR) and macroscopic friction tests. Both polyelectrolyte brushes exhibited hydrophilic properties. The contact angle of the poly(MPC) brush surface against water was ca. 0° in air and the contact angle of the air bubble in water was ca. 170°. The air bubble in water hardly attached to the poly(MPC) brush surface, indicating super hydrophilic characteristics. NR measurements of poly(MPC) and poly(METAI) brushes showed that the grafted polymer chains were extended from the substrate surface in a good solvent such as water. Interestingly, NR study did not reveal the shrinkage of the brush chain in salt solution. The polyelectrolyte brushes immersed in both water and NaCl solution at various concentrations showed a low friction coefficient and low adhesion force.