Identification of an additional two-cysteine containing type I interferon in rainbow trout Oncorhynchus mykiss provides evidence of a major gene duplication event within this gene family in teleosts

Multiple type I interferons (IFNs) have recently been identified in salmonids, containing two or four conserved cysteines. In this work, a novel two-cysteine containing (2C) IFN gene was identified in rainbow trout. This novel trout IFN gene (termed IFN5) formed a phylogenetic group that is distinct from the other three salmonid IFN groups sequenced to date and had a close evolutionary relationship with IFNs from advanced fish species. Our data demonstrate that two subgroups are apparent within each of the 2C and 4C type I IFNs, an evolutionary outcome possibly due to two rounds of genome duplication events that have occurred within teleosts. We have examined gene expression of the trout 2C type I IFN in cultured cells following stimulation with lipopolysaccharide, phytohaemagglutinin, polyI:C or recombinant IFN, or after transfection with polyI:C. The kinetics of gene expression was also studied after viral infection. Analysis of the regulatory elements in the IFN promoter region predicted several binding sites for key transcription factors that potentially play an important role in mediating IFN5 gene expression.

First-principle study of extrinsic defects in CuScO2 and CuYO2

Using first-principles methods, we studied the extrinsic defects doping in transparent conducting oxides CuMO2 (M=Sc, Y). We chose Be, Mg, Ca, Si, Ge, Sn as extrinsic defects to substitute for M and Cu atoms. By systematically calculating the impurity formation energy and transition energy level, we find that Be-Cu is the most prominent extrinsic donor and Ca-M is the prominent extrinsic acceptor. In addition, we find that Mg atom substituting for Sc is the most prominent extrinsic acceptor in CuSCO2. Our calculation results are expected to be a guide for preparing n-type and p-type materials through extrinsic doping in CuMO2 (M=SC, y). (C) 2008 Elsevier B.V. All rights reserved.

Growth of SiGe heterojunction bipolar transistor using Si2H6 gas and Ge solid sources molecular beam epitaxy

N-p-n Si/SiGe/Si heterostructure has been grown by a disilane (Si2H6) gas and Ge solid sources molecular beam epitaxy system using phosphine (PH3) and diborane (B2H6) as n- and p-type in situ doping sources, respectively. X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) measurements show that the grown heterostructure has a good quality, the boron doping is confined to the SiGe base layer, and the Ge has a trapezoidal profile. Postgrowth P implantation was performed to prepare a good ohmic contact to the emitter. Heterojunction bipolar transistor (HBT) has been fabricated using the grown heterostructure and a common-emitter current gain of 75 and a cut-off frequency of 20 GHz at 300 K have been obtained. (C) 2001 Elsevier Science B.V. All rights reserved.

The effect of substrate orientation on the morphology of InAs nanostructures on (001) and (11n)A/B(n=1-5) InP substrates

Strained InAs nanostructures have been grown by solid-source molecular beam epitaxy in In0.52Al0.48As matrix on different InP substrate surfaces ((0 0 1) and (1 1 n)A/B (n = 1 - 5)). The morphology of the nanostructures was characterized using atomic force microscopy (AFM). The AFM results reveal interesting differences in the size, shape, and alignment of the nanostructures between different oriented surfaces. It was found that some faceted nanostructures tend to form on A-type surfaces, the shape and the alignment of these nanostructures show clear dependence on the substrate orientation. Samples grown on (0 0 1) and B-type surfaces showed preferentially dense round dots. Dots formed on (1 1 3)B, (1 1 3)B and (1 1 5)B surfaces have a higher dot density and size homogeneity, which shows a potential for the production of high-quality and customized self-assembled quantum dots for photonics applications. (C) 2000 Elsevier Science B.V. All rights reserved.

Improved neutron radiation hardness for Si detectors: Application of low resistivity starting material and or manipulation of N-eff by selective filling of radiation-induced traps at low temperatures

Radiation-induced electrical changes in both space charge region (SCR) of Si detectors and bulk material (BM) have been studied for samples of diodes and resistors made on Si materials with different initial resistivities. The space charge sign inversion fluence (Phi(inv)) has been found to increase linearly with the initial doping concentration (the reciprocal of the resistivity), which gives improved radiation hardness to Si detectors fabricated from low resistivity material. The resistivity of the BM, on the other hand, has been observed to increase with the neutron fluence and approach a saturation value in the order of hundreds k Omega cm at high fluences, independent of the initial resistivity and material type. However, the fluence (Phi(s)), at which the resistivity saturation starts, increases with the initial doping concentrations and the value of Phi(s) is in the same order of that of Phi(inv) for all resistivity samples. Improved radiation hardness can also be achieved by the manipulation of the space charge concentration (N-eff) in SCR, by selective filling and/or freezing at cryogenic temperatures the charge state of radiation-induced traps, to values that will give a much smaller full depletion voltage. Models have been proposed to explain the experimental data.

practical type checking of functions defined on context-free languages

A type checking method for the functional language LFC is presented. A distinct feature of LFC is that it uses Context-Free (CF) languages as data types to represent compound data structures. This makes LFC a dynamically typed language. To improve efficiency, a practical type checking method is presented, which consists of both static and dynamic type checking. Although the inclusion relation of CF.languages is not decidable,a special subset of the relation is decidable, i.e., the sentential form relation, which can be statically checked.Moreover, most of the expressions in actual LFC programs appear to satisfy this relation according to the statistic data of experiments. So, despite that the static type checking is not complete, it undertakes most of the type checking task. Consequently the run-time efficiency is effectively improved. Another feature of the type checking is that it converts the expressions with implicit structures to structured representation. Structure reconstruction technique is presented.

Theoretical Analysis of Gain and Threshold Current Density for Long Wavelength GaAs-Based Quantum-Dot Lasers

Quantum dot gain spectra based on harmonic oscillator model are calculated including and excluding excitons. The effects of non-equilibrium distributions are considered at low temperatures. The variations of threshold current density in a wide temperature range are analyzed and the negative characteristic temperature and oscillatory characteristic temperature appearing in that temperature range are discussed. Also,the improvement of quantum dot lasers＇ performance is investigated through vertical stacking and p-type doping and the optimal dot density, which corresponds to minimal threshold current density,is calculated.

Improved neutron radiation hardness for Si detectors: Application of low resistivity starting material and or manipulation of N-eff by selective filling of radiation-induced traps at low temperatures

Radiation-induced electrical changes in both space charge region (SCR) of Si detectors and bulk material (BM) have been studied for samples of diodes and resistors made on Si materials with different initial resistivities. The space charge sign inversion fluence (Phi(inv)) has been found to increase linearly with the initial doping concentration (the reciprocal of the resistivity), which gives improved radiation hardness to Si detectors fabricated from low resistivity material. The resistivity of the BM, on the other hand, has been observed to increase with the neutron fluence and approach a saturation value in the order of hundreds k Omega cm at high fluences, independent of the initial resistivity and material type. However, the fluence (Phi(s)), at which the resistivity saturation starts, increases with the initial doping concentrations and the value of Phi(s) is in the same order of that of Phi(inv) for all resistivity samples. Improved radiation hardness can also be achieved by the manipulation of the space charge concentration (N-eff) in SCR, by selective filling and/or freezing at cryogenic temperatures the charge state of radiation-induced traps, to values that will give a much smaller full depletion voltage. Models have been proposed to explain the experimental data.

Radiosensitivity of hepatoma cell lines and human normal liver cell lines exposed in vitro to carbon ions and argon ions at the HIRFL

Human hepatoma (SMMC-7721) and normal liver (L02) cells were irradiated with c-rays, 12C6+ and 36Ar18+ ion beams at the Heavy Ion Research Facility in Lanzhou (HIRFL). By using the Calyculin-A induced premature chromosome condensation technique, chromatid-type breaks and isochromatid-type breaks were scored separately. Tumor cells irradiated with heavy ions produced a majority of isochromatid break, while chromatid breaks were dominant when cells were exposed to c-rays. The relative biological effectiveness (RBE) for irradiation-induced chromatid breaks were 3.6 for L02 and 3.5 for SMMC-7721 cell lines at the LET peak of 96 keVlm 1 12C6+ ions, and 2.9 for both of the two cell lines of 512 keVlm 1 36Ar18+ ions. It suggested that the RBE of isochromatid-type breaks was pretty high when high-LET radiations were induced. Thus we concluded that the high production of isochromatid-type breaks, induced by the densely ionizing track structure, could be regarded as a signature of high-LET radiation exposure.

Investigation of Chemical Bond Characteristics, Thermal Expansion Coefficients and Bulk Moduli of alpha-R2MoO6 and R2Mo2O7 (R = rare earths) by Using a Dielectric Chemical Bond Method

Theoretical researches are performed on the alpha-R2MoO6 (R = Y, Gd, Tb Dy, Ho, Er, Tm and Yb) and pyrochlore-type R2Mo2O7 (R = Y, Nd, Sm, Gd, Tb and Dy) rare earth molybdates by using chemical bond theory of dielectric description. The chemical bonding characteristics and their relationship with thermal expansion property and compressibility are explored. The calculated values of linear thermal expansion coefficient (LTEC) and bulk modulus agree well with the available experimental values. The calculations reveal that the LTECs and the bulk moduli do have linear relationship with the ionic radii of the lanthanides: the LTEC decreases from 6.80 to 6.62 10(-6)/K and the bulk modulus increases from 141 to 154 GPa when R goes in the order Gd, Tb Dy, Ho, Er, Tm, and Yb in the alpha-R2MoO6 series; while in the R2Mo2O7 series, the LTEC ranges from 6.80 to 6.61 10(-6)/K and the bulk modulus ranges from 147 to 163 GPa when R varies in the order Nd, Sm, Gd, Tb and Dy.

Nanocomposite multilayer film of preyssler-type polyoxometalates with fine tunable electrocatalytic activities

Through layer-by-layer (LBL) assembly technique, iron oxide (Fe3O4) nanoparticles coated by poly (diallyldimethylammonium chloride) (PDDA) and Preyssler-type polyoxometalates (NH4)(14)NaP5W30O110.31H(2)O (P5W30) were alternately deposited on quartz and ITO substrates, and 4-aminobenzoic acid modified glassy carbon electrodes. Thus-prepared multilayer films were characterized by UV-visible spectroscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry. It was proved that the multilayer films are uniform and stable. And the electrocatalytic activities of the multilayer films can be fine-tuned by adjusting the assembly conditions in the LBL assembly process, such as the pH of the assembly solution. The multilayer films fabricated from P5W30 solutions dissolved in 0.1 M H2SO4 exhibit high electrocatalytic response and sensitivity toward the reduction of two substrates of important analytical interests, HNO2 and IO3- whereas the films assembled with P5W30 solutions dissolved in 1.0 M H2SO4 show remarkable electrocatalytic activity for the hydrogen evolution reaction (HER). Furthermore, the electrocatalytic properties of the HER of the latter film can be obtained from the former film upon exposure to 1.0 M H2SO4 for several hours.

Facile syntheses and characterization of hyperbranched poly(ester-amide)s from commercially available aliphatic carboxylic anhydride and multihydroxyl primary amine

A new method for synthesis of novel hyperbranched poly(ester-amide)s from commercially available AA' and CBx type monomers has been developed on the basis of a series of model reactions. The hyperbranched poly(ester-amide)s with multihydroxyl end groups are prepared by thermal polycondensation of carboxyl anhydrides (AA') and multihydroxyl primary amine (CBx) without any catalyst and solvent. The reaction mechanism in the initial stage of polymerization was investigated with in situ H-1 NMR. In the initial stage of the reaction, primary amino groups of 2-amino-2-ethyl-1,3-propanediol (AEPO) or tris(hydroxymethyl)aminomethane (THAM) react rapidly with anhydride, forming an intermediate which can be considered as a new AB(x) type monomer. Further self-polycondensation reactions of the AB. molecules produce hyperbranched polymers. Analysis using H-1 and C-13 NMR spectroscopy revealed the degree of branching of the resulting polymers ranging from 0.36 to 0.55. These hyperbranched poly(ester-amide)s contain configurational isomers observed by C-13 and DEPT C-13 NMR spectroscopy, possess high molecular weights with broad distributions and display glass-transition temperatures (T(g)s) between 7 and 96 degreesC.

Improved n-type organic transistors by introducing organic heterojunction buffer layer under source/drain electrodes

N-type organic thin-film transistors (OTFTs) employing hexadecafluorophthalocyaninatocopper (F16CuPc) as active layer and p-type copper phthalocyanine (CuPc) as buffer layer are demonstrated. The highest field-effect mobility is 7.6x10(-2) cm(2)/V s. The improved performance was attributed to the decrease of contact resistance due to the introduction of highly conductive F16CuPc/CuPc organic heterojunction. Therefore, current method provides an effective path to improve the performance of OTFTs.

Influence of Mn-O-Mn bond angle on the magnetic and electronic properties in YBaMn2O5

The influence of the Mn-O-Mn bond angle on the magnetic and electronic properties of YBaMn2O5 was studied by density functional theory, which was implemented in the CASTEP code. In practical calculation, both G- and A-type antiferromagnetic (AFM) orderings were considered. The calculated results indicated that G-type is more stable than A-type, in agreement with both experiment and previous theoretical study. It is also interesting to note that a transition from G-type to A-type at an Mn-O-Mn angle of ca. 170 degrees was found upon increasing Mn-O-Mn angle. Therefore, the calculation suggested that what is essential to stabilize the G-type AFM state is the reduction of the Mn-O-Mn bond angle. For both magnetic orderings, the compound changes from semiconductor to metal with the increase of Mn-O-Mn angle.

Synthesis and characterization of hyperbranched poly(ester-amide)s from commercially available dicarboxylic acids and multihydroxyl primary amines

A new method for syntheses of hyperbranched poly(ester-amide)s from commercially available A(2) and CBx type monomers has been developed on the basis of a series of model reactions. The aliphatic and semiaromatic hyperbranched poly(ester-amide)s with multihydroxyl end groups are prepared by in situ thermal polycondensation of intermediates obtained from dicarboxylic acids (A(2)) and multihydroxyl primary amines (CBx) in N,N-dimethylformamide. Analyses of FTIR, H-1 NMR, and C-13 NMR spectra revealed the structures of the polymers obtained. The MALDI-TOF MS of the polymers indicated that cyclization side reactions occurred during polymerization. The hyperbranched poly(ester-amide) s contain configurational isomers observed by C-13 and DEPT C-13 NMR spectroscopy. The DBs of the polymers were determined to be 0.38-0.62 by H-1 NMR or quantitive C-13 NMR and DEPT 135 spectra. These polymers exhibit moderate molecular weights, with broad distributions determined by size exclusion chromatography ( SEC), and possess excellent solubility in a variety of solvents such as N, N- dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, and ethanol, and display glass-transition temperatures (T(g)s) between -2.3 and 53.2 degrees C, determined by DSC measurements.