Synthesis and Field Evaluation of Stereoisomers and Analogues of 5-Methylheptadecan-7-ol,an Unusual Sex Pheromone Component of the Lichen Moth,Miltochrista calamina

Females of the lichen moth, Miltochrista calamina (Arctiidae, Lithosiinae), were previously shown to produce 5-methylheptadecan-7-ol (1) as a sex pheromone. In field tests, males were attracted only by the (5R,7R)-isomer of the four stereoisomers that were prepared by separation from two mixtures of diastereoisomers. A new route to (5R,7R)-1 starting from (S)-propylene oxide was developed utilizing the S_N2 reaction of an optically active secondary tosylate and the Jacobsen hydrolytic kinetic resolution of an epoxide intermediate as key steps. Enantioselective HPLC analysis of the product and the antipode synthesized from (R)-propylene oxide confirmed their high enantiomeric excess (> 99 %). Using this stereospecific synthesis, six analogues with the same configuration as (5R,7R)-1 but with different alkyl chain(s) connected to the stereogenic centers were prepared in order to obtain GC/MS data and to examine the ability of M. calamina males to discriminate between them. The mass spectra of the synthetic analogues revealed characteristic fragment ions derived by cleavage around the methyl group in addition to that at the hydroxyl group. In field trapping tests, five out of the six compounds were attractive to male M. calamina moths, indicating that the males distinguished the configurations of methyl and hydroxyl groups but were less able to perceive differences in the lengths of the two alkyl chains in the pheromone.     

Highly efficient reverse transfection with siRNA in multiple wells of microtiter plates

We have developed an efficient and inexpensive method of reverse transfection from the solid phase to suppress genes with siRNA. The method enabled the realization of (i) a high efficiency of transfection; (ii) transfection of various types of cell; (iii) a high efficiency of gene knockdown by siRNA; (iv) a low toxicity to cells; and (v) a long-term stabilization (more than 210 d) of attached transfection mixture including siRNA in multiple wells. Although array-based reverse transfection has advantages in terms of miniaturization, the method has the advantage of enabling the inclusion of various soluble factors, such as humoral factors, drugs and ligands that affect gene expression, because the liquid phase is partitioned within the individual wells of each microtiter plate. Our method of reverse transfection with siRNA in multiple wells is a powerful and high-throughput tool for the analysis of signaling pathways.     

Evaluation of physical properties of human hair by diffuse reflectance near-infrared spectroscopy

The objective of the present study is to develop a novel nondestructive, simple, and quick method to evaluate the friction, twist, and gloss of human hair based on near-infrared diffuse reflectance (NIR-DR) spectroscopy and chemometrics. NIR-DR spectra were measured for human hair, which was collected from eleven Japanese women (age 5-44 years), by use of an optical fiber probe. Partial least squares (PLS) regression has been applied to the NIR-DR spectra of human hair after mean centering (MC), standard normal variate (SNV), and first derivative (1d) or second derivative (2d) analysis to develop calibration models that predict the friction, twist, and gloss of human hair. We identified the most suitable wavenumber region for the evaluation of each physical property. Correlation coefficients and standard errors of calibration of the PLS calibration models for the friction, twist, and gloss of hair were calculated to be 0.96 and 0.023, 0.81 and 3.27, and 0.90 and 0.36, respectively. Thus, the calibration models have high accuracy.     

Magnetocaloric effect of (ErxR1−x)Co2 (R = Ho, Dy) for magnetic refrigeration between 20 and 80 K

Two series of RCo₂ compounds, (Er_xHo_1−x)Co₂ and (Er_yDy_1−y)Co₂, were investigated as magnetic refrigerants for hydrogen liquefaction. A large magnetocaloric effect (MCE) was observed just above the Curie temperature (T_c) of these compounds which both undergo a first-order magnetic transition. The isothermal entropy change ΔS and the adiabatic temperature change ΔT_ad of these compounds were larger than those of other Laves-phase materials such as RAl₂ and RNi₂. However, the temperature range of the large MCE for these compounds was limited. It has been shown that T_c increases almost linearly against the de Gennes factor, and can be controlled by changing the concentration of the rare earth elements while maintaining a first-order transition. By measuring the magnetization and heat capacity, we obtained temperature entropy (T–S) diagrams, which are essential for analyzing the magnetic refrigeration cycle. Both series of compounds showed high potential for use in a regenerative thermal cycle, especially as a combination of several compositions to cover a wide temperature range.     

Study on rapid analysis method of pesticide contamination in processed foods by GC-MS and GC-FPD

A simple and rapid method using GC-MS and GC-FPD for the determination of pesticide contamination in processed food has been developed. Pesticides were extracted from a sample with ethyl acetate in the presence of anhydrous sodium sulfate, then cleaned up with a combination of mini-columns, such as macroporous diatomaceous earth, C18, GCB (graphite carbon black) and PSA. Recovery tests of 57 pesticides (known to be toxic or harmful) from ten kinds of processed foods (butter, cheese, corned beef, dried shrimp, frozen Chinese dumplings, grilled eels, instant noodles, kimchi, retort-packed curry and wine) were performed, and the recovery rates were mostly between 70% and 120%. This method can be used to judge whether or not processed foods are contaminated with pesticides at potentially harmful levels.     

A novel approach to a fine particle coating using porous spherical silica as core particles

The applicability of porous spherical silica (PSS) was evaluated as core particles for pharmaceutical products by comparing it with commercial core particles such as mannitol (NP-108), sucrose and microcrystalline cellulose spheres. We investigated the physical properties of core particles, such as particle size distribution, flow properties, crushing strength, plastic limit, drying rate, hygroscopic property and aggregation degree. It was found that PSS was a core particle of small particle size, low friability, high water adsorption capacity, rapid drying rate and lower occurrence of particle aggregation, although wettability is a factor to be carefully considered. The aggregation and taste-masking ability using PSS and NP-108 as core particles were evaluated at a fluidized-bed coating process. The functional coating under the excess spray rate shows different aggregation trends and dissolution profiles between PSS and NP-108; thereby, exhibiting the formation of uniform coating under the excess spray rate in the case of PSS. This expands the range of the acceptable spray feed rates to coat fine particles, and indicates the possibility of decreasing the coating time. The results obtained in this study suggested that the core particle, which has a property like that of PSS, was useful in overcoming such disadvantages as large particle size, which feels gritty in oral cavity; particle aggregation; and the long coating time of the particle coating process. These results will enable the practical fine particle coating method by increasing the range of optimum coating conditions and decreasing the coating time in fluidized bed technology.     

Fatigue behaviour of dissimilar friction stir welds between wrought and cast aluminium alloys

Wrought aluminium alloy, A6016-T4, was welded to cast one ADC12 by a friction stir welding technique. A6016 was set on the advancing side, while ADC12 was on the retreating side based on the pre-tensile test results. The dissimilar welds exhibited lower fatigue strengths than A6016 but higher than that of ADC12. Fatigue strengths increased when the tool was offset into ADC12, which could be explained based on the risk volume concept. When ADC12 was set on the advancing side, the fatigue strengths decreased. Microstructural observation revealed that the macroscopic structure in the stir zone drastically changed by putting ADC12 on the advancing side, and insufficient mixing of dissimilar alloys resulted in the lower fatigue strengths.     

Structure and biomechanics of culms of Phragmites australis used for reeds of Japanese wind instrument “hichiriki”

Hichiriki is a traditional Japanese double‐reed wind instrument used in Japanese ancient imperial court music, gagaku, which has been performed since the 7th century. The best reeds for hichiriki have been made of culms or stems of Phragmites australis (P. australis) that are harvested from only a limited reed bed at Udono near Kyoto. The aim of this study is to elucidate why the stems from Udono are the best materials for hichiriki reeds. Plant anatomy was examined for choice stems of P. australis grown in different reed beds in Japan as well as morphology, and the local indentation hardness and Young's modulus of tissues on the cross‐sections of some representatives of hichiriki reeds were measured. It is concluded that the good stems for hichiriki reeds have an outer diameter of about 11 mm, a wall thickness of about 1 mm and comparatively homogeneous structure where harder materials, such as epidermis, hypodermis, sclerenchymatous cells, and vascular bundle sheaths with hard walls, are orderly deployed with softer materials such as parenchyma cells and vascular bundles. This structure has smaller differences of hardness and Young's modulus between the hard and soft materials in the reed, providing the best music performance. Microsc. Res. Tech. 78:260–267, 2015. © 2015 Wiley Periodicals, Inc.