Designing novel bulk metallic glass composites with a high aluminum content.

The long-standing challenge for forming Al-based BMGs and their matrix composites with a critical size larger than 1 mm have not been answered over the past three decades. In this paper, we reported formation of a series of BMG matrix composites which contain a high Al content up to 55 at.%. These composites can be cast at extraordinarily low cooling rates, compatible with maximum rod diameters of over a centimetre in copper mold casting. Our results indicate that proper additions of transition element Fe which have a positive heat of mixing with the main constituents La and Ce can appreciably improve the formability of the BMG matrix composites by suppressing the precipitation of Al(La,Ce) phase resulted from occurrence of the phase separation. However, the optimum content of Fe addition is strongly dependant on the total amount of the Al content in the Al-(CoCu)-(La,Ce) alloys.

Enhancing glass-forming ability via frustration of nano-clustering in alloys with a high solvent content.

The glass-forming ability (GFA) of alloys with a high-solvent content such as soft magnetic Fe-based and Al-based alloys is usually limited due to strong formation of the solvent-based solid solution phase. Herein, we report that the GFA of soft magnetic Fe-based alloys (with >70 at.% Fe to ensure large saturation magnetization) could be dramatically improved by doping with only 0.3 at.% Cu which has a positive enthalpy of mixing with Fe. It was found that an appropriate Cu addition could enhance the liquid phase stability and crystallization resistance by destabilizing the α-Fe nano-clusters due to the necessity to redistribute the Cu atoms. However, excessive Cu doping would stimulate nucleation of the α-Fe nano-clusters due to the repulsive nature between the Fe and Cu atoms, thus deteriorating the GFA. Our findings provide new insights into understanding of glass formation in general.

Preparation and application of monoclonal antibodies against hepatitis C virus nonstructural proteins.

AIM: To prepare hybridoma cell lines that secrete monoclonal antibodies against hepatitis C virus (HCV) recombinant proteins NS3 and NS5 and to evaluate their use in the study of HCV NS3 and NS5 antigen distribution in human liver tissue. METHODS: Hybridoma cell lines were generated using spleen cells from BALB/C mice immunized with recombinant NS3 and NS5 proteins, following conventional protocols. Antibody-secreting cells were screened by solid phase ELISA and cloned by limited dilution. The specificity of the monoclonal antibodies was determined by testing hybridoma culture supernatants by Western blots of E. coli expressing the recombinant HCV proteins and ELISA with HCV core and hepatitis B virus (HBV) antigens. The monoclonal antibodies were employed in immunohistochemistry studies to determine the distribution of HCV NS5 and NS3 antigens in 51 paraffin embedded human liver tissue samples. RESULTS: Eight hybridoma cell lines secreting monoclonal antibodies against HCV NS3 and NS5 proteins were generated and named 2B6, 2F3, 3D8, 3D9, 8B2, 6F11, 4C6 and 7D9. Only one of them, 2B6 (secreting antibodies against NS3 protein), cross-reacted with the C7 polypeptide, a different recombinant NS3 polypeptide. The rest of the cell lines showed no cross-reactivity with HCV core or HBV antigens. In addition, monoclonal antibodies against NS3 antigens did not cross-react with NS5 antigens, and vice versa. In immunohistochemistry studies, these monoclonal antibodies did not detect HCV antigens in specimens from patients infected only with HBV (n = 20). In HCV-infected specimens (n = 31), the rates of positive detection of NS3 and NS5 antigens were 51.6% (16/31) and 54.9% (17/31), respectively. Six of these 31 specimens were from patients infected only with HCV and half of them were positive for HCV NS3 and NS5 antigens. In specimens from patients co-infected with HBV and HCV (n = 25), the rates of NS3 and NS5 antigen positive detection were 52% (13/25) and 56% (14/25), respectively, which are similar to those obtained in samples from patients infected only with HCV. In specimens from chronic active cirrhosis patients, the rates of HCV NS3 and NS5 antigen detection were 70.6% (12/17) and 76.5% (13/17), respectively. CONCLUSION: We successfully prepared monoclonal antibodies that are specific against recombinant HCV NS3 and NS5 proteins and could be useful for clinical immunohistochemistry diagnosis.