Metal-Matrix Embedded Phononic Crystals

Metal-matrix embedded phononic crystals (MMEPCs) can be applied for noise and vibration reduction. Metal-matrix embedded phononic crystals (MMEPCs) consisting of double-sided stubs (single “hard” stubs/composite stubs) were introduced. The introduced MMEPCs are deposited on a two-dimensional locally resonant phononic crystal plate that consists of an array of rubber fillers embedded in a steel plate. The lower frequency complete bandgap will be produced in the MMEPCs with composite stubs by decoupling the spring-mass system of the resonator by means of the rubber filler. Then, the out-of-plane bandgap and the in-plane bandgap can be adjusted into the same lowest frequency range by the composite stubs. The broad complete bandgap will be produced in the metal-matrix embedded phononic crystals with single “hard” stubs by producing new kinds of resonance modes (in-plane and out-of-plane analogous-rigid modes) by introducing the single “hard” stubs, and then the out-of-plane bandgap and the in-plane bandgap can be broadened into the same frequency range by the single “hard” stubs. The proposed MMEPCs can be used for noise and vibration reduction

A new Schiff base nickel(II) complex: {5,5′-dihydr­oxy-2,2′-[o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}nickel(II) methanol disolvate

The monomeric title nickel(II) complex of a salicylaldimine, [Ni(C20H14N2O4)]·2CH3OH, was obtained by the reaction of 2,4-dihydroxy­benzaldehyde and 1,2-phenyl­enediamine with nickel(II) acetate. The NiII atom is coordinated by two N atoms [Ni—N = 1.839 (2) Å] and two O atoms [Ni—O = 1.8253 (19) Å] in an approximately square-planar geometry. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into a chain along [001]

Bis[2-(2-hydroxy-3-meth­oxy­phen­yl)benzimidazolium] tetrachlorido­cuprate(II) methanol disolvate

In the title compound, (C14H13N2O2)2[CuCl4]·2CH4O, the geometry of the CuC14 2− ions (Cu site symmetry 2) is inter­mediate between tetra­hedral and square-planar. The dihedral angle between the benzimidazole and benzene ring systems is 8.74(14)°. A network of N—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds helps to consoldiate the structure. Aromatic π–π stacking inter­actions involving the benzimidazole ring system, with a centroid–centroid distance of 3.785 (3) Å, also occur

Temperature dependence of electron-spin relaxation in a single InAs quantum dot at zero applied magnetic field

The temperature-dependent electron spin relaxation of positively charged excitons in a single InAs quantum dot (QD) was measured by time-resolved photoluminescence spectroscopy at zero applied magnetic fields. The experimental results show that the electron-spin relaxation is clearly divided into two different temperature regimes: (i) T < 50 K, spin relaxation depends on the dynamical nuclear spin polarization (DNSP) and is approximately temperature-independent, as predicted by Merkulov et al. (ii) T > about 50 K, spin relaxation speeds up with increasing temperature. A model of two LO phonon scattering process coupled with hyperfine interaction is proposed to account for the accelerated electron spin relaxation at higher temperatures.Comment: 10 pages, 4 figure

Partial characterization of glutathione S-transferases from different field populations of Liposcelis bostrychophila

Glutathione S-transferases (GSTs) from different field populations of Liposcelis bostrychophila (Psocoptera: Liposcelididae) were purified by glutathione-agarose affinity chromatography and characterized subsequently by their Michaelis-Menten kinetics toward the artificial substrates 1-chloro- 2,4-dinitrobenzene (CDNB) and reduced glutathione (GSH). The specific activity of the affinity of purified GST toward CDNB was highest in lab population, 2.7-fold higher than that of Guanghan population with the lowest value observed. GSTs of lab population exhibited higher apparent Michaelis-Menten constants (Km) and higher maximal velocity (Vmax) values than those of Jianyang and Guanghan populations, revealing that the latter two populations exhibited significantly higher affinities to the test substrates. Inhibition kinetics showed that all test compounds (ethacrynic acid, curcumin, diethyl maleate, bromosulfalein, and carbosulfan) possessed significant inhibitory effects on GSTs. Curcumin appeared to be the most effective inhibitor. Compared to the other compounds, diethyl maleate and carbosulfan exhibited their I50s (the concentration required to inhibit 50% of GSTs activity) at higher concentrations.Keywords: GSTs, purification, Psocids, Xenobiotic compounds, Field population

Genome-wide analysis of microRNAs in relation to pupariation in oriental fruit fly

Insect metamorphosis is a complex process involving drastic morphological and physiological changes. microRNAs (miRNAs) are a class of endogenous small non-coding RNAs that play key roles in regulating various biological processes, including metamorphosis, by post-transcriptional repression of mRNAs. The oriental fruit fly, Bactrocera dorsalis, is one of the most destructive insect pests in many Asian countries and the Pacific Islands. The regulatory role of miRNAs in B. dorsalis metamorphosis is unclear. To better understand the molecular regulatory mechanisms of miRNAs in pupariation, Illumina sequencing of the wandering stage (WS), the late WS and the white puparium stage of B. dorsalis were performed. Two hundred forty-nine miRNAs, including 184 known miRNAs and 65 novel miRNAs, were obtained. Among these miRNAs, 19 miRNAs were differentially expressed in pupariation, and eight miRNAs showed relative high expression levels (>50 TPM), of which five differentially expressed miRNAs (DEMs) had target differentially expressed genes (DEGs) predicted by the expected miRNA-mRNA negative regulation pattern using the Illumina HiSeq data. Four sets of DEMs and their predicted target DEGs were confirmed by qPCR. Of the four miRNAs, two miRNAs were down-regulated: miR-981, which may target pdpc, and Bdo-novel-mir-55, which potentially regulates spsX1, psB/C, and chit3. The other two miRNAs were up-regulated: let-7a-3p, which possibly controls lap, and Bdo-novelmir-24, which may regulate ipc and sp1/2. This study provides a useful resource to elucidate the regulatory role of miRNAs and understand the molecular mechanisms of metamorphosis