Investigation on activating individual living monocytic U937 cell by interleukin-6 using Raman tweezers

We investigate the activation of living monocytic U937 cells induced by interleukin-6 （IL-6） at the single cell level. We employ home-built Raman tweezers to measure the Raman spectra of living U937 cells with and without IL-6 at the single cell level. Raman peaks of amide III, amide I, DNA backbone, as well as guanine and adenine in U937 cells, change at 1312, 1652, 1090, and 1576 cm ？1 , respectively, shortly after IL-6 is added in the medium. The change is a dynamic temporal process. In the activation process of U937 cells induced by IL-6, the protein signals recover in 20 min, while the nucleic acid signals continue to increase for 20 min. The results reveal that the biochemical cascades of activation in signal transduction induced by IL-6 can be investigated in situ at the single cell level.     

Multi-carrier transport properties in p-type ZnO thin films

By the aid of temperature- and magnetic-field-dependent Hall effect measurements, we have extracted the multi-carrier transport information in N-doped and N–In codoped p- ZnO thin films grown on Si substrates through mobility spectrum analysis. It is found that owing to the compensation between free electrons and holes, the two-dimensional hole gas from ZnO/Si interface layers becomes determinant and results in the high p-type conductivity and high hole mobility in the ZnO samples. Compared with N-doping, the N–In codoping introduces many In donors and increases acceptor incorporation, as well as enhancing the free hole mobility due to the short-range dipole-like scattering.     

Determination of piracetam in rat plasma by LC–MS/MS and its application to pharmacokinetics

A sensitive and selective liquid chromatography–tandem mass spectrometry method for the determination of piracetam in rat plasma was developed and validated over the concentration range of 0.1–20 µg/mL. After addition of oxiracetam as internal standard, a simplified protein precipitation with trichloroacetic acid (5%) was employed for the sample preparation. Chromatographic separation was performed by a Zorbax SB‐Aq column (150 × 2.1 mm, 3.5 µm). The mobile phase was acetonitrile–1% formic acid in water (10:90 v/v) delivered at a flow rate of 0.3 mL/min. The MS data acquisition was accomplished in multiple reaction monitoring mode with a positive electrospray ionization interface. The lower limit of quantification was 0.1 µg/mL. For inter‐day and intra‐day tests, the precision (RSD) for the entire validation was less than 9%, and the accuracy was within the 94.6–103.2% range. The developed method was successfully applied to pharmacokinetic studies of piracetam in rats following single oral administration dose of 50 mg/kg. Copyright © 2010 John Wiley & Sons, Ltd.     

Effect of the distribution of palladium over the cross section of an ion-exchanger fiber on catalyst activity in a water deoxygenation process

A procedure for the preparation of a fibrous palladium-containing catalyst for the removal of dissolved oxygen from water was developed. This procedure includes the preliminary modification of an anionexchanger fiber with carboxylate ions, which makes it possible to localize metal clusters in a thin subsurface layer of a fiber at the subsequent stages of the ion-exchange introduction of palladium into the carrier and the reduction of palladium. It was found that the higher activity of fibrous palladium-containing catalysts based on the citrate forms of anion exchangers, as compared with that of samples based on the chloride forms, was due to the predominant arrangement of reduced metal clusters on the external surface and an adjacent thin layer of the fiber.     

Structure of recurrent sequences of median filters

In this paper, we first obtain a fundamental result on the structure of recurrent sequences of median filters. Based on this result, we then classify recurrent sequences and discuss their periodicity.     

A black hole preying on the star for a gamma-ray burst of GRB080503: Evidence for the second event in this new class

In this paper, we critically assess GRB080503, a short gamma-ray burst with very bright extended emission (about 30 times the gamma-ray fluence of the initial spike). The light curve of the prompt γ-ray emission of GRB080503 resembles that of GRB 060614 which has been suggested to be due to an event from an intermediate mass black hole (IMBH) preying on a star. We therefore propose that GRB080503 is also due to a similar event; the mass of the IMBH is estimated to be about 4.6×10⁴ solar masses, and the engulfed star had about the same mass and size as the Sun. We also estimate that the total burst energy is about 7.67 × 10⁵⁰ ergs.

     

具交叉感染的流行病模型的数学分析

In this paper,an initial boundary value problem with homogeneous Neumann boundary condition is studied for a reaction-diffusion system which models the spread of infectious diseases within two population groups by means of self and criss-cross infection mechanism. Existence,uniqueness and boundedness of the nonnegative global solution (u1,u2,u3,u4),existence of the limit of the solution as t→+∞,namely,(u1,u2,u3,u4)→(u*1,0,u*3,0),are proved.     

电脉冲沉积铝化物及铝化物-Y_2O_3涂层

采用电脉冲沉积技术在 2 0碳钢表面上获得了冶金结合的晶粒尺寸约为几十到几百纳米的铝化物和铝化物 弥散Y2 O3复合微晶涂层。60 0℃空气中氧化 10 0h的结果表明 ,电脉冲沉积获得的两种涂层均可显著地降低 2 0碳钢的氧化速率并提高氧化层的抗剥落性能。用AFM ,SEM ,EDS和XRD对铝化物涂层及氧化层进行了分析 ,并讨论了两种涂层提高抗氧化性能的作用机制     

Scheme for implementing quantum dense coding with W-class state in cavity QED

An experimentally feasible protocol for realizing dense coding by using a class of W-state in cavity quantum electrodynamics （QED） is proposed in this paper. The prominent advantage of our scheme is that the successful probability of the dense coding with a W-class state can reach 1. In addition, the scheme can be implemented by the present cavity QED techniques.     

Anomalous magnetic properties of an iron film system deposited on fracture surfaces of α-Al2O3 ceramics

An iron film percolation system is fabricated by vapour-phase deposition on fracture surfaces of α-Al2O3 ceramics. The zero-field-cooled （ZFC） and field-cooled （FC） magnetization measurement reveals that the magnetic phase of the film samples evolve from a high-temperature ferromagnetic state to a low-temperature spin-glass-like state, which is also demonstrated by the temperature-dependent ac susceptibility of the iron films. The temperature dependence of the exchange bias field He of the iron film exhibits a minimum peak around the temperature T=5 K, which is independent of the magnitude of the cooling field Hcf. However, for T 〉 10K, （1） He is always negative when Hcf=2kOe and （2） for Hcf= 20 kOe （1Oe≈80 A/m）, He changes from negative to positive values as T increases. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase.