Dietary effects of phytoecdysones in the leek-moth,Acrolepiopsis assectella Zell. (Lepidoptera: Acrolepiidae)

Incorporation of certain phytoecdysones (ecdysterone, polypodine B, and ponasterone A) into a semisynthetic artificial diet induces pathophysiological effects in larvae of the leek-moth (Acrolepiopsis assectella Zell., Acrolepiidae). The effects include lethality of the newly hatched, first-instar larvae; special ecdysial failures associated with the appearance of larvae with two head capsules; and developmental anomalies during metamorphosis. The effective range of dietary ecdysteroid, as evaluated by larval mortality, varies from 25 to 250 ppm. The EC₅₀ value is 100 ppm for polypodine B and 130 ppm for ecdysterone. The dietary effects of the phytoecdysones are similar to the previously observed effects caused by the dried flowers, but not leaves, of the leek plant. However, the active compound of the leek flowers is a saponin.     

基于IEEE 802.15.6的无线体域网自适应MAC协议

针对无线体域网MAC协议自适应性不高且能效低的问题,提出一种基于IEEE 802.15.6的无线体域网自适应MAC协议（A-MAC）。对IEEE 802.15.6的超帧结构进行改进,竞争接入阶段和非竞争接入阶段的长度根据产生各优先级数据的节点所占的比例进行调整。竞争接入阶段又被划分为三个子阶段,子阶段的长度根据数据优先级情况进行动态调整。所有节点在竞争接入阶段按照信道接入策略竞争接入信道。最后仿真结果表明,在吞吐量、能耗和网络时延方面,使用A-MAC协议的网络性能明显优于使用IEEE 802.15.6 MAC和CA-MAC协议的网络性能。     

Phase Equilibria in the Pr - Re - B System

X-ray diffraction methods have been applied to the component interaction in the system Pr - Re - B. Isothermal sections of the phase diagram have been constructed for 600°C (region of more than 33 at.% Pr) and 800°C (region less than 33 at.% Pr). The previously known borides Pr₂Re₃B₆, Pr₈Re_13–x B₁₂, Pr₇(Re₄B₄)₆ are confirmed, which have specific structural types. A new ternary compound has been found, Pr₃ReB₆ (structure not determined).__________Translated from Poroshkovaya Metallurgiya, Nos. 1–2(441), pp. 46–51, January–February, 2005.     

Electrochemical reduction of 2,2′-dinitrobiphenyl-X type substances in nonaqueous and aprotic solvents

The oxidation-reduction behaviour of 2,2′-dinitrobiphenyl-X type compounds (X = O, S, NH, CH₂, CO) and of 2,2′-dinitrobiphenyl in non-aqueos acetonitrile and dimethylformamide and their mixtures with water was investigated by polarography and cyclic voltammetry at mercury drop electrodes. In combination with ESR-spectroscopy the reversible formation of a radical anion has been found in the primary one-electron step which is followed by a second one-electron uptake leading to a di-anion. According to the group X, to the water content and to the supporting electrolyte the second reduction step is or is not reversible. The ease of reduction decreases in the following sequence with changing X : CO > NH > S > O> - >CH₂(ie E_{$\text{1}\text{2}$} becomes more negative). According to the composition of the solution further 2 or 6 electrons are consumed at more negative potentials, giving to the 2-hydroxylamine-2′-nitro derivative or to the 2,2′-di-hydroxylamine compound, respectively. In solutions with more than approx 5–10% (by vol.) of water the reduction of the two nitro groups proceeds either in a single 8-electron step or in two 4-electron waves. In 90–94% acetonitrile solutions with alkali metal cation salts as supporting electrolytes a dip appears on the limiting current of the overall 8-electron reduction wave with the dme. The inhibition of the reduction process has been interpreted in terms of formation at the electrode of an insoluble precipitate of tri-ions resulting from the interaction between the di-anion and the alkali metal cations.     

镇村公交下一种新型智能公交到站时间预测算法

提出了一种新型模糊隶属度算法,针对镇村公交线路进行公交到站时间预测。算法在速度集Vmin,Vmid1, Vmid2,...Vmidn-2,Vmidmax层面上对GPS公交运行数据进行分析,用模糊策略标定不同速度所属速度集,并用r解释不同速度集下公交行驶道路百分比,最终采用GPS历史数据和即时数据预测公交到站时间。结果表明,新的公交运行数据可进行算法更新以保证公交到站预测精度大于95%。     

Electrophoretic Determination of Symmetric and Asymmetric Dimethylarginine in Human Blood Plasma with Whole Capillary Sample Injection

Asymmetric and symmetric dimethylarginines are toxic non-coded amino acids. They are formed by post-translational modifications and play multifunctional roles in some human diseases. Their determination in human blood plasma is performed using capillary electrophoresis with contactless conductivity detection. The separations are performed in a capillary covered with covalently bonded PAMAPTAC polymer, which generates anionic electroosmotic flow and the separation takes place in the counter-current regime. The background electrolyte is a 750 mM aqueous solution of acetic acid with pH 2.45. The plasma samples for analysis are treated by the addition of acetonitrile and injected into the capillary in a large volume, reaching 94.5% of the total volume of the capillary, and subsequently subjected to electrophoretic stacking. The attained LODs are 16 nm for ADMA and 22 nM for SDMA. The electrophoretic resolution of both isomers has a value of 5.3. The developed method is sufficiently sensitive for the determination of plasmatic levels of ADMA and SDMA. The determination does not require derivatization and the individual steps in the electrophoretic stacking are fully automated. The determined plasmatic levels for healthy individuals vary in the range 0.36–0.62 µM for ADMA and 0.32–0.70 µM for SDMA.     

Effect of Chitosan-Coated Alginate Microspheres on the Permeability of Caco-2 Cell Monolayers

ABSTRACT

Alginate microspheres were prepared by emulsification/internal gelation and coated with chitosan. The ability of chitosan-coated alginate microspheres to increase the paracellular transport across Caco-2 cell monolayers was evaluated in comparison to uncoated microspheres and chitosan solutions. Transport studies were performed by using a permeability marker, Lucifer Yellow (LY), and by measuring the transepithelial electric resistance (TEER) variations. Furthermore, the occurrence of cytotoxic effects was assessed by evaluating neutral red uptake in viable cells and lactate dehydrogenase (LDH) release from damaged cells. A 3-fold increase on LY permeability was obtained for coated microspheres when compared to chitosan solutions. TEER variations were in agreement with permeability results. Chitosan solutions exhibited a dose-dependent toxicity, but coated microspheres did not decrease the viability of cells. Chitosan-coated alginate microspheres have potential to be used as carriers of poorly absorbable hydrophilic drugs to the intestinal epithelia and possibly increase their oral bioavailability.     

基于S2Si＋jQuery的高校短信平台设计与实现

目前新型的开源集成框架S2Si提供了轻量级、高效率的软件开发模型。为了实现高质量的、交互性强的Web应用,把jQuery这一目前较为流行的前端技术整合到了S2Si框架中,构建了一种新的基于S2Si＋jQuery的应用开发框架。最后阐述了该框架在高校短信平台系统中的实现过程和应用效果。     

New compounds with a Y2ReB6 type structure

The Ln’Mo’MB ternary systems (where Ln is Tm, Yb, Lu) are studied by means if X-ray analysis. New compounds of the Y2ReB6 structure type (space group Pbam) were found: Tm₂MoB₆ (a=0.9210(2), b=1.1409(1), c=0.35983(6) nm), Yb₂MoB₆ (a=0.9068(3), b=1.1394(3), c=0.3588(1) nm), Lu₂MoB₆ (a=0.9031(4), b=1.1364(3), c=0.35526(9) nm); the atomic factors of the last structure are refined up to R=0.068. Lattice parameters for the known boride Er₂MoB₆ are refined: a=0.925492), b=1.1449(3), c=0.36065(6) nm. The smoothly decreasing lattice parameters and unit cell volumes in the series Ln₂MoB₆ (Ln is Er, Tm, Yb, Lu) point to the trivalent state of the rare earth atoms (REM).