Simultaneous determination of N-methylcarbamate and urea pesticides in agricultural products by LC/MS

A simultaneous determination method of 7 N-methylcarbamate and 7 urea pesticides in agricultural products by liquid chromatography/mass spectrometry (LC/MS) has been developed. Under reversed-phase liquid chromatographic conditions, 14 pesticides were analyzed using electrospray ionization (ESI) with simultaneous acquisition of positive ions and negative ions. Fourteen pesticides were extracted with acetone, 10% NaCl solution was added, and the pesticides were re-extracted with dichloromethane. The extract was concentrated under reduced pressure, and dissolved in methanol. The detection limits of 14 pesticides ranged from 0.0012 to 0.0056 microgram/g. The recoveries of pesticides were from 36.5 to 112.5% [RSD (n = 3) ranged from 0.5 to 48.1%] for 4 agricultural products.     

Identification Method of Dynamic Coefficients of Fluid Film Bearings for HDD Spindle Motors

Fluid film bearings are widely used as support elements of rotating shaft for HDD （hard disk drive） spindle motors. Recently, the opportunity for the HDD spindle motors exposed to external vibration has been increasing because the HDDs are used for various information related equipments such as mobile PCs, car navigation systems. Hence, the rotating shaft has a possibility to come in contact with the bearing and it causes wear or seizure to the bearing surface. In order to avoid the problems, it is extremely important to enhance the dynamic characteristics of the fluid film bearings for spindles. However, verification from both theory and experiment of dynamic characteristics such as spring coefficients and damping coefficients is rare and few. In this paper, the bearing vibration characteristics when the HDD spindle is oscillated are investigated theoretically and experimentally. And then the identification method ofoil film coefficients of fluid film bearing spindles is described.     

Analysis of bis(trifluoromethylsulfonyl)imide-doped paramagnetic graphite intercalation compound using F very fast magic angle spinning nuclear magnetic resonance

F atoms bonding to paramagnetic/conductive graphene layers in accepter-type graphite intercalation compounds (GICs) are analyzed using very fast magic angle spinning nuclear magnetic resonance, which is applied for the first time on ¹⁹F nuclei to investigate paramagnetic materials. In the bis(trifluoromethylsulfonyl)imide(TFSI)-doped GIC, C–F bonds between fluorine atoms and graphene layers conform to a weak bonding of F to the graphene sheets. TFSI anions intercalated in the GIC do not show overall molecular motion; even at room temperature only the CF₃ groups rotate.     

Strong Influences of Melting Time and Tm3+ Concentration on Blue Up-Conversion Photoluminescence for Tm3+/Yb3+ Co-Doped TeO2–TlO0.5–ZnO Glass

In this study, by a conventional melt quenching method, we synthesized novel up-conversion phosphors of 60TeO₂–30TlO_0.5–(9−x)ZnO–xTm₂O₃–1Yb₂O₃ (x = 0.1–0.5) glasses, whose system was recently developed in our collaborative group, and their blue up-conversion photoluminescence (UCPL) of Tm³⁺ ions via three-step energy transfer from near-infrared (NIR) sensitizer of Yb³⁺ ions was observed. In particular, the substantial rate of the energy transfer <γ_d5> in the third step from Yb³⁺ to Tm³⁺ under excitation at 975 nm, which determined the final blue UCPL intensity, was estimated as a function of the rare-earth concentration. With an aid of analytical methods of PL lifetime and Judd–Ofelt theory, it was revealed that the highest energy transfer rate <γ_d5> was achieved to be 2.07 × 10⁻¹⁷ cm³/s for x = 0.2, and further increasing Tm₂O₃ content x in the fixed Yb₂O₃ resulted in the decrease in the energy transfer rate <γ_d5>. One of the plausible causes was concentration quenching of Yb³⁺ ions. The other was back-transfer from Tm³⁺ to Yb³⁺ ions. The influence of the condition of glass synthesis and the melting time on <γ_d5> was also discussed.     

Highly Sensitive Terahertz Sensing of Glycerol-Water Mixtures with Metamaterials

We demonstrate the highly sensitive terahertz (THz) sensing of a water-glycerol mixture poured on a metamaterial surface using reflection-based THz time domain spectroscopy. The reflectance at the resonant dip frequency changes significantly with glycerol concentration. The detection sensitivity is about 8 times higher than that compared to the case without a metamaterial structure. We also investigate how sensitivity depends on the Q factor of the metamaterial resonance for highly absorptive media, such as a water solution in the THz region.     

野外试验场场址土壤蒸发量的计算

为了确定野外试验场场址由地表向地下土壤渗入的水量,必须计算场址的地表蒸发量。在野外试验场安装了环境气象自然监装置,每１０分钟自动记录一次监测数据,观测历时二年多。将所获取和气象数据和有关参数用Ｐｅｎｍａｎ法,能量平衡法,失窃代法和湍流相关法四种方法计算了土壤蒸发量,计算结果表明,试验场址的土壤年蒸发量与降水量基本一致,在４００－６００ｍｍ／ａ之间。     

A 60-ns 16-Mbit CMOS DRAM with a transposed data-line structure

Low-noise, high-speed circuit techniques for high-density DRAMs (dynamic random-access memories), as well as their application to a single 5-V 16-Mb CMOS DRAM with a 3.3-V internal operating voltage for a memory array, are described. It was found that data-line interference noise becomes unacceptably high (more than 25% of the signal) and causes a serious problem in 16-Mb DRAM memory arrays. A transposed data-line structure is proposed to eliminate the noise. Noise suppression below 5% is confirmed using this transposed data-line structure. A current sense amplifier is also proposed to maintain the data-transmission speed in common I/O lines, in spite of a reduced operating voltage and increased parasitic capacitance loading in the memory array. A speed improvement of 10 ns is achieved. Using these circuit techniques, a 16-Mb CMOS DRAM with a typical RAS access time of 60 ns was realized     

Viscoelastic properties and microstructures of 11S globulin and soybean protein isolate gels: Magnesium chloride-induced gels

Heat-induced gels of 11S globulin (11S) or soybean protein isolate (SPI) were prepared using magnesium chloride (MgCl₂) as a coagulant. Viscoelastic properties and microstructures of 11S and SPI gels were quantified using dynamic viscoelastic measurement (DVM) and confocal laser scanning microscopy (CLSM). The addition of sodium chloride was necessary for 11S and SPI to form MgCl₂-induced gels. DVM indicated that 11S formed stiffer and more solid gels than SPI under all experimental conditions. CLSM showed that the microstructures of 11S gels were coarser and more heterogeneous than SPI gels in comparable conditions. The microstructures of 11S gels were highly affected by MgCl₂ concentration whereas those of SPI gels were relatively insensitive to MgCl₂ concentration. The microstructures of 11S and SPI gels were analyzed by two parameters: the fractal dimension and the average density of gel networks. Compared to SPI, 11S forms MgCl₂-induced gels with a lower fractal dimension and a higher density of network structures.     

Antihypertensive effect of an angiotensin converting enzyme inhibitory peptide from enzyme modified cheese

Two angiotensin converting enzyme (ACE)-inhibitory peptides were isolated from enzyme modified cheese (EMC) and their amino acid sequences were identified as Leu-Gln-Pro and Met-Ala-Pro. The EMC was prepared by a combination of Protease N, Umamizyme, and Flavourzyme 500L. Both peptides were derived from beta-casein, f 88-90 and f 102-104, respectively. Met-Ala-Pro showed strong ACE inhibitory activity (IC50=0.8 mum) and antihypertensive activity in spontaneously hypertensive rats (SHR) after single oral administration. The IC50 value of Met-Ala-Pro was not affected by pre-incubation with ACE, suggesting that this peptide was a true ACE-inhibitory peptide. We report here, for the first time antihypertensive peptides from EMC.     

Centronuclear Myopathy Caused by Defective Membrane Remodelling of Dynamin 2 and BIN1 Variants

Centronuclear myopathy (CNM) is a congenital myopathy characterised by centralised nuclei in skeletal myofibers. T-tubules, sarcolemmal invaginations required for excitation-contraction coupling, are disorganised in the skeletal muscles of CNM patients. Previous studies showed that various endocytic proteins are involved in T-tubule biogenesis and their dysfunction is tightly associated with CNM pathogenesis. DNM2 and BIN1 are two causative genes for CNM that encode essential membrane remodelling proteins in endocytosis, dynamin 2 and BIN1, respectively. In this review, we overview the functions of dynamin 2 and BIN1 in T-tubule biogenesis and discuss how their dysfunction in membrane remodelling leads to CNM pathogenesis.