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The Cu–10 %Fe–1.5 %Ag in situ composite with high strength, high conductivity and low cost was prepared, and its hot deformation behavior was investigated by isothermal compression test with true strain of 0.69, temperature range of 750–950 °C and strain rate of 0.002–1.000 s−1. The flow stress–strain response shows the characterization of dynamic recrystallization (DRX), and the peak stress increases gradually with deformation temperature decreasing and strain rate increasing. The deformation activation energy of the composite for DRX is calculated as 241.864 kJ·mol−1. The constitutive relation of the composite was got by Arrhenius equation. Furthermore, according to the dynamic material modeling and Kumar–Prasad’s instability criteria, the processing map was constructed and the unsafe regions for hot deformation were analyzed. Based on the processing map and microstructural evolution, the optimal parameter range for hot deformation processing is 750–863 °C at the strain rate of 0.002–0.013 s−1.

Aluminum alloy A6061 and mild steel Q235 was welded using resistance spot welding with an interlayer of AlCu28. The mechanical properties of the joint were investigated; the effects of various welding parameters on nugget diameter and tensile shear load of the joints were systematically discussed. The results reveal that it is effective to weld aluminum alloy and mild steel using resistance spot welding with an interlayer of AlCu28.

A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.

Based on the hot compression tests of AZ31B magnesium alloy, the trend of flow stress was analyzed and constitutive equation was established. Using Deform-3D Microsoft, the process of magnesium alloy wheel was numerical simulated. The effect of fraction coefficient and heating temperature on extrusion load and radial load on die surface was studied. It was shown that variety of these loads was tardo at prophase back-extrusion while violent at anaphase stage. The fraction coefficient was an important factor in total compression load and radial load on die surface was affected obviously by forming temperature.

Previous studies have shown that PRRSV nsp11, which was an endoribonuclease, was an interferon antagonist, however, the mechanism that nsp11 inhibited IFN-β production was unclear. To explore whether the endoribonuclease was required for nsp11 to disrupt the IFN-β production, substitutions of the presumed catalytic histidine and lysine residues of nsp11 were introduced into plasmid pcDNA 3.1-FLAG. The results showed that mutation that inactivated endoribonuclease made nsp11 lose its ability to inhibit Poly(I:C)-induced IFN-β promoter activity. In conclusion, our present work indicated that the endoribonuclease activity of nsp11 was essential for nsp11 to inhibit the IFN-β induction.

This paper expatiates the prominent effect of axial compression ratios on the ductility of reinforced concrete frame columns and the limits of the ratios in Code for Seismic Design of Buildings and summarizes the ductility design methods of frame columns with high compression ratios. The principles of value engineering were adopted to analyze the major factors affecting the ductility of reinforced concrete frame columns. The cost of columns with high compression ratios and different types of ties in a real project was calculated and relevant analysis and evaluations were conducted according to Value Coefficient Discriminance. At last the optimum ductility design method for frame columns with high compression ratios was put forth, with which reference can be made in design.

With the calculation methods for the sectional curvature ductility of reinforced concrete flexural components, analysis was conducted on the factors affecting the formation of plastic hinges at the ends of RC frame beams and their rotational capacities; on the basis of which, singly-doubly reinforced rectangular section method for flexural design calculation was put forth, which is favorable to the realization of beam hinge mechanism. The analysis of a practical design case shows that the method proposed is not only beneficial to the formation of plastic hinges at the beam ends and their rotational capacities, but also results in considerable reduction of longitudinal reinforcement, hence lowering of cost, ease of construction, so that it is worthy of popularization and application in design practice.

There are many advantages of magnesium alloy such as light mass, nonrattling and electromagnetic interference shield. Yet, its ductility was poor at room temperature and plastic forming was difficulty due to its close-packed hexagonal structure. In this paper, the superplasticity of magnesium alloy AZ91D was explored and the relationship between flow stress and true strain were achieved at different temperature by tensile tests. It was found that the flow stress of AZ91D as cast was less than 20MPa at 340-450°Cand superplastic deformation could be used to manufacture magnesium alloy parts. Utilized superplastic air bulking mold, AZ91D seamless pipes with variable cross-section were manufactured successfully based on process parameters being optimized. Moreover, the relationship between loading path of internal pressure and wall thickness was analyzed also.

The deformation processed Cu-based in-situ composite was a kind of structural function materials with high physical and mechanical performance and used widely in large scale integrated circuit. Especially, the sheet material of Cu-Fe in-situ composites was interested to researchers because the Fe was cheaper and the use of sheets was more widely in electron industry. In this study, the sheets of Cu-10Fe-1Ag in-situ composite were achieved by cold rolling which the thickness was from 6mm to 2.56mm, 1.28mm, 0.64mm and 0.32mm. Corresponding, the rolling ratio was 4.9, 5.3, 5.9 and 6.6. The maximum strength was 722Mpa at the rolling ratio 4.9. The conductivity was measured also with maximum 59.5% IACS. The experimental results show that the tensile strength and electrical resistance increase with the increasing of rolling strain. Although the conductivity of Cu-Fe in-situ composites was not very high, the matching of strength and conductivity was favorable. It is feasible that the high performance Cu-based in-situ composite can be obtained by cold rolling with merits of materials cheaper, melting simple and usage wide

The extracellular domain of the boFcgamma2R gene was constructed and cloned into the Escherichia coli expression vector pET-28a. The recombinant protein was expressed at high level in E. coli BL21(DE3) and existed mainly as inclusion bodies. The inclusion bodies were solubilized in 6 M guanidine hydrochloride and refolded by rapid dilution. After renaturation, the purity of the recovered recombinant protein was up to 95%. ELISA assay showed that the renatured recombinant protein could inhibit bovine IgG2 binding to expressed boFcgamma2R on the COS-7 cell surface with an IC50 value of 0.68 microM. The overall yield of the active rsbo2R was up to 20 mg/l of culture. Crystals of the rsbo2R were grown at 293 K by the hanging-drop vapour diffusion method showed weak diffraction.

The IL-2Ralpha chain (CD25, Tac) is an essential component of high affinity IL-2Rs, playing critical role for the immune specificity of antigen-activated T-cell clonal expansion. Up to now, no duck cytokine receptor has been described. Here, the cDNA segment of a duck cytokine receptor (duCD25), encoding a 226 aa precursor protein with a 20 aa signal peptide, was isolated. Then a novel mouse monoclonal antibody (mAb) was generated using the prokaryotically expressed duCD25 protein as immunogen. Using this mAb, the endogenous duCD25 molecule was localized on the surface of duck lymphocytes, and the duck IL-2-induced lymphocyte proliferation was further inhibited. Furthermore, flow cytometry analysis showed that duCD25 positive cells were upregulated in ducks infected with avian influenza virus (H9N2). Our findings confirm that duCD25 is a receptor of duck interleukin-2, and duCD25 positive cells play a potential role in H9N2 virus infection.

To identify the linear epitope for Fc-binding on the bovine IgG2 Fc receptor (boFcgamma2R), peptides derived from the membrane-distal extracellular domain (EC1) of boFcgamma2R corresponding to the homologous region of human FcalphaRI were synthesized. Binding of bovine IgG2 to the different peptides was tested by Dot-blot assay, and the peptide showing maximal binding was further modified by truncation and mutation. The minimum effective peptide 82FIGV85 located in the putative F-G loop of the EC1 domain was found to bind bovine IgG2 specifically and inhibit the binding of bovine IgG2 to the receptor. The Phe82, Ile83 and Val85 residues within the linear epitope were shown to be critical for IgG2-binding. Such functional epitope peptide should be very useful for understanding the IgG-Fcgamma interaction and development of FcR-targeting drugs.

Infectious bursal disease virus (IBDV) is the causative agent of infectious bursal disease, which is one of the most important and widespread infectious diseases in commercial chickens. Conformational epitopes have been reported in the highly variable region of the VP2 protein of IBDV. In the present study, a random heptapeptide library was screened by using monoclonal antibodies (mAbs), YNW17 and YNW29, directed to the VP2 of IBDV and two peptide motifs, D-X-P-R and A-R-G, were identified. The motifs are present on the N and C terminal sequences of the highly variable region of VP2. Synthetic overlapping peptides covering the motifs on VP2 were analyzed by Dot- ELISA with the mAbs and two epitopes 197CDSSDRPRVYTIT209 and 329ARGSLAVTI337 identified. The above epitopes were also recognized by chicken anti-IBDV sera and shown to inhibit the binding of their mAbs to recombinant VP2. Both mAbs and sera from mice immunized with the conjugated epitope-peptides were able to neutralize serotype I IBDV. These results indicated that the epitopes are two neutralizing linear B-cell epitopes and would be useful for the development of peptide-based IBD vaccines.

We expressed firstly the Capsid protein gene defecting the nuclear localization signal (NLS) of Porcine circovirus type II (PCV2) in Escherichia coli as a fusion protein with glutathione S-transferase (rGST-dCap protein). The purified rGST-dCap protein and the recombinant NLS-defected Cap protein of PCV2 (rdCap protein) from the purified rGST-dCap protein reacted specifically with swine antiserum to PCV2. Furthermore, the obtained monoclonal antibodies (mAbs) to rdCap protein were shown to bind to PCV2 particles replicated in PK15 cell and capsid protein (Cap protein) of PCV2 expressed in PK15 cells, respectively. mAbs to rdCap protein also revealed the neutralizing ability to PCV2 particles. These results demonstrated that rGST-dCap protein expressed in E. coli was folded correctly or at least partly, and mAbs to rdCap protein possessed the binding epitopes of PCV2 particles whereas mAbs 4C4 and 3F6 to rdCap protein remained the neutralization epitope of PCV2 particle, showing a possibility of neutralizing mAb to rdCap protein as an immnuotherapeutic agent and a potential of rGST-dCap protein as a vaccine antigen or serodiagnostic reagent.

RNA-dependent RNA polymerase (RdRp) is the replicase of positive-strand RNA viruses. Expression and characterization of the replicase are the first steps in the elucidation of the virus replication mechanism. We expressed nonstructural protein 5B (NS5B) of classical swine fever virus (CSFV) as a fusion protein with green fluorescent protein (GFP) in porcine kidney cells (PK-15 cells), natural host cells of CSFV. The expressed CSFV NS5B-GFP fusion protein possessed RdRp activity. By fluorescence microscope it was observed that the density of the fusion protein near cytoplasmic membranes was higher than that in other parts of cells. This was in contrast to the distribution of the GFP alone which was uniformly distributed throughout the cytoplasm. The GFP is a signal for the location of NS5B in a host cell that allows in vitro and in vivo investigation of the distribution of plus-strand RNA virus RdRp.

Faceted micropits obtained by electrochemical etching of a single quasicrystal of an Al-Pd-Mn icosahedral phase have been examined by optical and electron microscopy. Anodic etching of the flat surface of a fivefold plane in a solution composed of CH3OH and HNO3(3:1 in volume ratio) reveals a variety of icosahedrally faceted micropits which originated from pre-existing microvoids and etch pits of pentagonal pyramid shape due to the other origins, probably structural defects inside the specimen. As the dissolution progresses, the micropits make successive changes in their shapes, ending in pentagonal pyramids before they vanish.

The shapes of micro-pits formed in an Al-Pd-Mn icosahedral quasicrystal have been examined by alternating sequence of electrochemical etching and scanning electron microscopy (SEM) observations. Anodic etching was executed on fivefold and twofold surfaces of the single-quasicrystal. Prolonged anodic etching in a solution of CH 3 OH + HNO 3 (volume ratio 3 : 1) followed by SEM observations has revealed that two different types of micro-pits, i.e. pre-existing micro-voids and electrochemical etch-pits, develop into the same regular shape. The micro-pits develop into a pentagonal pyramid on the fivefold surface, and a flat-bottomed rhombic pyramid on the twofold surface. It is shown that these two polyhedral etch-figures correspond to two different sections of a regular rhombic triacontahedron.

In the present investigation, the rationale for the design, synthesis, and biological evaluation of potent inhibitors of neuronal Na+ channels is described. N,N'-diaryl- and N-aryl-N-aralkylguanidine templates were locked in conformations mimicking the permissible conformations of the flexible diarylguanidinium ion (AS+, AA+, SS+). The resulting set of constrained guanidines termed "lockamers" (cyclophane, quinazoline, aminopyrimidazolines, aminoimidazolines, azocino- and tetrahydroquinolinocarboximidamides) was examined for neuronal Na+ channel blockade properties. Inhibition of [14C]guanidinium ion influx in CHO cells expressing type IIA Na+ channels showed that the aminopyrimidazoline 9b and aminoimidazoline 9d, compounds proposed to lock the N,N'-diarylguanidinium in an SS+ conformation, were the most potent Na+ channel blockers with IC50's of 0.06 microM, a value 17 times lower than that of the parent flexible compound 18d. The rest of the restricted analogues with 4-p-alkyl substituents retained potency with IC50 values ranging between 0.46 and 2.9 microM. Evaluation in a synaptosomal 45Ca2+ influx assay showed that 9b did not exhibit high selectivity for neuronal Na+ vs Ca2+ channels. The retention of significant neuronal Na+ blockade in all types of semirigid conformers gives evidence for a multiple mode of binding in this class of compounds and can possibly be attributed to a poor structural specificity of the site(s) of action. Compound 9b was also found to be the most active compound in vivo based on the high level of inhibition of seizures exhibited in the DBA/2 mouse model. The pKa value of 9b indicates that 9b binds to the channel in its protonated form, and log D vs pH measurements suggest that ion-pair partitioning contributes to membrane transport. This compound stands out as an interesting lead for further development of neurotherapeutic agents.

A pair of α-cyano analogues of decarboxylated S-adenosylmethionine (2a and 2b) were synthesized as potential enzyme activated, irreversible inhibitors of the[pyruvoyl enzyme S-adenosylmethionine decarboxylase (AdoMet-DC). Each of these analogues acts as an irreversible inactivator for ADoMet-DC from Escherichia coli (IC50 values of 9 and 50 μM, respectively). These analogues also inactivate human AdoMet-DC, with KI values of 246.6 and 7.2 μM, and kinact values of 0.29 and 0.03 min−1, respectively.

In 2006 China experienced outbreaks of a severe form of porcine reproductive and respiratory syndrome (PRRS) characterized by high fever, morbidity and mortality in swine irrespective of age. It is thought that secondary bacterial infections may contribute to the generation of this severe form of the disease. To determine the mechanisms by which a highly pathogenic PRRSV strain causes high fever we used an in vitro model to investigate the production of the pro-inflammatory cytokines IL-1β and TNF-α by macrophages in response to inoculation with PRRSV with or without LPS. Firstly we demonstrated, through an animal inoculation trial, that the isolate HN07-1 was a highly pathogenic strain and sequencing showed that the virus had the same genomic characteristics as previously described isolates. Porcine alveolar macrophage (PAM) cultures infected with PRRSV strains showed increased cytokine secretion and this was greater in the more virulent strain. Addition of LPS further increased cytokine secretion and again the effect was greater with the more virulent strain. Incubation of PAMs with PRRSV strain HN07-1 resulted in a significant increase in surface CD14 expression. This may explain the synergistic action between PRRSV and LPS in the induction of inflammatory cytokine secretion seen in the PAMs and so offer an explanation for the high fever that is characteristic of infections by the highly pathogenic PRRSV.

Receptors for the Fc region of IgG (Fc gamma Rs) play a critical role in the immune system and host protection against infection. In this study, we describe the cloning, mRNA expression and IgG subclass specificity of ovine Fc gamma receptor I (ovFc gamma RI). The ovFc gamma RI cDNA contains a 1047bp open-reading frame, and is predicted to encode a 349 amino acid trans-membrane glycoprotein composed of three immunoglobulin-like domains, a trans-membrane region and a short cytoplasmic tail. The overall identity of the ovine Fc gamma RI to its cattle, human and mouse counterparts at the level of the amino acid sequence was 92%, 61% and 54%, respectively. Rosetting analysis shows that COS-7 cells were transfected with an expressional vector carrying the cDNA open-reading frame of ovFc gamma RI and expressed this receptor on the surface. Identification of ovine Fc gamma RI will aid in the understanding of molecular basis of the ovine immune system and further studies of the receptor function.

The highly pathogenic H5N1 avian influenza virus emerged from China in 1996 and has spread across Eurasia and Africa, with a continuous stream of new cases of human infection appearing since the first large-scale outbreak among migratory birds at Qinghai Lake. The role of wild birds, which are the natural reservoirs for the virus, in the epidemiology of the H5N1 virus has raised great public health concern, but their role in the spread of the virus within the natural ecosystem of free-ranging terrestrial wild mammals remains unclear. In this study, we investigated H5N1 virus infection in wild pikas in an attempt to trace the circulation of the virus. Seroepidemiological surveys confirmed a natural H5N1 virus infection of wild pikas in their native environment. The hemagglutination gene of the H5N1 virus isolated from pikas reveals two distinct evolutionary clades, a mixed/Vietnam H5N1 virus sublineage (MV-like pika virus) and a wild bird Qinghai (QH)-like H5N1 virus sublineage (QH-like pika virus). The amino acid residue (glutamic acid) at position 627 encoded by the PB2 gene of the MV-like pika virus was different from that of the QH-like pika virus; the residue of the MV-like pika virus was the same as that of the goose H5N1 virus (A/GS/Guangdong [GD]/1/96). Further, we discovered that in contrast to the MV-like pika virus, which is nonpathogenic to mice, the QH-like pika virus is highly pathogenic. To mimic the virus infection of pikas, we intranasally inoculated rabbits, a species closely related to pikas, with the H5N1 virus of pika origin. Our findings first demonstrate that wild pikas are mammalian hosts exposed to H5N1 subtype avian influenza viruses in the natural ecosystem and also imply a potential transmission of highly pathogenic avian influenza virus from wild mammals into domestic mammalian hosts and humans.

The immunochromatographic lateral flow strip test is a one-step test that facilitates low-cost, rapid identification of various analytes at the point of care. We have developed lateral flow strip tests for the specific qualitative or semiquantitative detection of antigens, antibodies, and haptens, such as drug residues. Here, we describe in detail the preparation of three examples of the strip tests for detection of (a) the infectious bursal disease virus; (b) Trichinella specific antibodies, and (c) Clenbuterol residues in urine samples.

Receptors for the Fc regions of immunoglobin G (IgG) play a critical role in immunoregulation and immune defenses against pathogens. In this study, we describe the cloning, eukaryotic expression and IgG subclass specificity of ovine Fc gamma receptor III (FcγRIII). The newly cloned ovine FcγRIII cDNA contains a 940 bp open-reading frame (ORF), and is predicted to encode a 250 amino acid transmembrane glycoprotein composed of two immunoglobulin-like extracellular domains, a transmembrane region and a short cytoplasmic tail. The overall identity of the ovine FcγRIII amino acid sequence to its cattle, pig and human counterparts was 83.2%, 62.0%, 60.7%, respectively. Overlapping PCR was performed with the extracellular domain of ovine FcγRIII and the transmembrane and intracellular region of ovine Fc gamma chain to construct a chimeric receptor. Rosetting analysis showed that transfected COS-7 cells required Fc receptor gamma chain for the expression of FcγRIII on the surface. COS-7 cells expressing FcγRIII were able to bind chicken erythrocytes sensitized with ovine IgG1, but not IgG2. Identification of ovine FcγRIII will further our understanding of the ovine immune system.

The protective immune response against porcine circovirus 2 (PCV2) infection in mice was characterized using flow cytometric analysis (FCM), assays of antibody (of different IgG isotypes) and viraemia, and histopathological examination. An open reading frame 2 plasmid (pORF2) and the capsid protein (Cap) of PCV2 were used as DNA and subunit vaccines, respectively. In FCM analysis, although pORF2 and Cap alone showed comparable efficacy in eliciting lymphoproliferative responses and Cap-specific CD4+ T cells, pORF2 was superior to the Cap protein in triggering CD8+ T cells. A virus neutralization assay showed that pORF2 evoked stronger recall virus-neutralizing (VN) antibody responses than the Cap protein on PCV2 challenge. Correspondingly, VN antibody kinetics coincided with those of Cap-specific IgG2a, but not with the kinetics of IgG and IgG1. Following virus challenge, real-time PCR and histopathological analysis confirmed that only low viral DNA loads and mild microscopic lesions appeared in pORF2-immunized mice. These findings indicate that CD8+ T cells and VN antibody responses correlating mainly with Cap-specific IgG2a play crucial roles in protecting against PCV2 infection, and that the protective immunity induced by the pORF2 plasmid is superior to that induced by the PCV2 Cap protein.

Porcine circovirus type 2 (PCV2) has been recently associated with a number of disease syndromes, especially postweaning multisystemic wasting disease (PMWS). Herein, an alternative indirect enzyme-linked immunosorbent assay (ELISA) for detection of PCV2 antibody was developed using nuclear localization signal-truncated capsid protein of PCV2 produced in Escherichia coli (CAP ELISA). This assay was validated by comparison with an indirect immunofluorescence assay (IIF) and a PCV2-based ELISA. The diagnostic sensitivity (DSN), specificity (DSP) and accuracy of the CAP ELISA were 95.3%, 93.9% and 95.1%, compared with IIF on 1080 field serum samples, and 93.3%, 84.2% and 91.1%, compared with the PCV2-based ELISA on 79 field sera, respectively. Cross-reactivity assay showed that this assay was PCV2-specific. Repeatability tests revealed that the coefficients of variation of positive sera within and between runs were less than 15%. This ELISA is simpler to produce and perform, time-saving and suitable for large scale surveys of PCV2 infection at low cost and the evaluation of the efficiency of various vaccines against PCV2.

To identify chicken IL-2R α chain (chCD25), the cDNA of chCD25 was cloned and mapped onto chicken chromosome 1. The polyclonal and monoclonal antibodies raised from the recombinant chCD25 specifically bound to the cell surface of splenic mononuclear cells (SMC) and inhibited chicken IL-2-dependent proliferation of T cells. Flow cytometry analysis revealed that chCD25 molecules could be expressed on the surface of monocytes/macrophages, thrombocytes, CD4+ and CD8+ cells as well as tissue cells. Importantly, the CD4+CD25+ and CD8+CD25+ cells were upregulated dramatically in chickens infected with H9N2 avian influenza virus. These results confirm that the cloned cDNA is the nucleotide sequence of chicken IL-2R, and suggest that chicken CD4+CD25+ and CD8+CD25+ cells may play an important role in immune responses induced by H9N2 virus, and the monoclonal antibodies to chCD25 may be useful for investigating biological functions of chicken regulatory T cells.

Outbreaks of a highly pathogenic avian influenza (H5N1) were reported in birds in more than eight Asian countries. We sought to identify the origin of this infection, and herein report the results of serological and virological monitoring of migrant wild waterfowl in mainland China. From a total of 493 serum samples, collected from 15 migratory wild waterfowl species for 9 months (from June 2004 to May 2005) in mainland China, we detected only low-level antibodies against influenza subtypes H2, H9 and H10 in the relict gull, little egret, black-crowned night heron, bar-tailed godwit, whimbrel and the common greenshank. No virus was identified from the 1052 cloacal and oropharyngeal swabs except dead bar-headed geese. These data show that the influenza type A virus subtypes H2-H13 did not circulate at detectable levels within the sampled population.

A rapid immunochromatographic lateral flow test strip was developed in a competitive format with the gold-conjugated monoclonal antibody to specifically determine the residues of Clenbuterol (CL), a beta-adrenergic agonist. The test strip is made up of a sample pad, a conjugate reagent pad, a test membrane containing a control line and a test line, and an absorbent pad. CL standard samples of 0, 0.1, 0.3, 0.9, 2.7, 8.1 ng/ml in swine urine were determined by the test strip. It was shown that detection limit of the test strip was as low as 0.1 ng/ml of CL and that the half of maximal inhibition concentration (IC50) in relative optical density was calculated to be 1.78+/-0.17 ng/ml under an optical density scanner. The sensitivity by eye measurement was 1.0 ng/ml. It takes 10 min to accomplish a test. Parallel analysis of urine samples from pigs fed with CL showed comparable results obtained from the test strip and GC-MS. Therefore, the test strip is very useful as a screening method for quantitative, semi-quantitative or qualitative detection of CL residues in swine urine.

A functional IP10-scFv fusion protein retaining the antibody specificity for acidic isoferritin and chemokine function was produced at high level in Esherichia coli (E. coli). IP10-scFv gene from the recombinant plasmid pc3IP104c9 was subcloned into pET28a fused to N-terminal His-tag sequence in frame and overexpressed in E. coli BL21(DE3). With an on-column refolding procedure based on Ni-chelating chromatography, the active fusion protein was recovered efficiently from inclusion bodies with a refolding yield of approximate 45% confirmed by spectrophotometer. The activity of refolded IP10-scFv was determined through sodium dodecyl sulfate–polyacrylamide gel electrophoresis, Western blotting and enzyme-linked immunosorbent assay. The results showed the fusion protein retains the specific binding activity to AIF with an affinity constant of 4.48 × 10−8 M as well as the chemokine function of IP-10. The overall yield of IP10-scFv with bioactivity in E. coli flask culture was more than 40 mg/L.

A functional single-chain Fv antibody fragment (scFv) specific for acidic isoferritin (AIF) was produced at high level in Escherichia coli. The variable regions of heavy chain (V(H)) and light chain (V(L)) from the hybridoma 4c9 were connected with a flexible linker using an assembly polymerase chain reaction. The construct of V(H)-linker-V(L) was inserted into a phagemid pCANTAB 5 E followed by selection with the Recombinant Phage Antibody System (RPAS). Anti-AIF scFv gene from the recombinant phagemid pCAN4c9 was subcloned into pET28a fused to N-terminal His-tag sequence in frame and overexpressed in E. coli BL21(DE3). With an on-column refolding procedure based on Ni-chelating chromatography, the active anti-AIF scFv was recovered efficiently from inclusion bodies with a refolding yield of approximate 75% confirmed by spectrophotometer. The activity of refolded scFv was determined through sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting and enzyme-linked immunosorbent assay. The results showed anti-AIF scFv retains the specific binding activity to AIF with an affinity constant of 7.29 x 10(-8) mol l(-1). The overall yield of anti-AIF scFv with bioactivity in E. coli flask culture was more than 60 mg l(-1).

We have grown a decagonal single quasicrystal with a size of centimeter order in an A172Co16Ni12 alloy by floating zone method at a growth rate of 0.5 mm/h. The single decagonal quasicrystal has been inspected by Laue X-ray as well as neutron diffraction, revealing a very high quasicrystalline quality. By quenching the liquid during growth, a flat solid-liquid interface has been directly observed. There exists solute redistribution at the growing solid-liquid interface. At steady state growth Al is enriched and Co, Ni are depleted in front of solid-liquid interface. Solute partition ratios of Al, Co and Ni were determined to be about 0.91, 1.57 and 1.08, respectively.

In this study, experiments were performed to clarify the grain-refining mechanisms of pure Mg cast by adding some grain refiners containing Al3Ti, TiC, TiB2, and AlB2 particles as heterogeneous nucleation sites. It is found that Al–5 mass % Ti, Al–3 mass % Ti–0.15 mass % C, Al–5 mass % Ti–0.2 mass % B, and Al–5 mass % Ti–1 mass % B alloys are effective grain refiners for pure Mg, as well as for pure Al and Al alloys. The favourable heterogeneous nucleation sites in these refiners are considered to be TiC, TiB2, and AlB2 particles.

Antibody-dependent enhancement (ADE) of virus infection caused by the uptake of virus-antibody complexes by FcγRs is a significant obstacle to the development of effective vaccines to control certain human and animal viral diseases. The activation FcγRs, including FcγRI and FcγRIIa have been shown to mediate ADE infection of virus. In the present paper, we showed that pocine FcγRIIb, an inhibitory FcγR, mediates ADE of PRRSV infection. Stable Marc-145 cell lines expressing poFcγRIIb (Marc-poFcγRII) were established. The relative yield of progeny virus was significantly increased in the presence of sub-neutralization anti-PRRSV antibody. The Fab fragment and normal porcine sera had no effect. Anti-poFcγRII antibody inhibited the enhancement of infection when cells were infected in the presence of anti-PRRSV antibody, but not when cells were infected in the absence of antibody. These results indicate that enhancement of infection in these cells by anti-PRRSV virus antibody is FcγRII-mediated. Identification of the inhibitory FcγR mediating ADE infection should expand our understanding of the mechanisms of pathogenesis for a broad range of infectious diseases and may open many approaches for improvements to the treatment and prevention of such diseases.

We have found that an epitaxial film of Au–Al alloy can be formed on a quasiperiodic surface of icosahedral Al72Pd19.5Mn8.5. Depositions of Au onto the quasiperiodic surface, which is perpendicular to one of the fivefold axes of Al72Pd19.5Mn8.5, were attempted in order to create a quasicrystal of a single element as an epitaxial film. Although the desired film was not obtained on the clean surface, an ordered layer of Au–Al alloy with icosahedral symmetry was formed in the presence of predeposited In, which worked as a surfactant. X-ray photoelectron diffraction (XPD) images for Au 4f and Al 2s emissions from the ordered layer indicate clear fivefold symmetric patterns which are coherent with the symmetry of the substrate. In addition, symmetric elements specific to the icosahedral symmetry are clearly recognized in these patterns, indicating that both Au and Al atoms are located in an icosahedral environment with long-range bond-orientational order.