Atom ordering in cuboctahedral Ni-Al nanoalloys

Energy calculations have been carried out on high-symmetry cuboctahedral Ni-Al nanoalloy clusters, of varying composition, with the interatomic interactions modelled by the Gupta many-body potential. Relaxations of cuboctahedral fragments cut from the bulk lattice of Ni₃Al, with 13-561 atoms, were undertaken, as were relaxations of high symmetry clusters with 55 and 147 atoms. The lowest energy isomers were found to be dominated by three factors: the tendency toward mixing due to the favourable energy of mixing, Δ_mixE; the size difference between nickel and aluminium; and the higher cohesive and surface energy of nickel compared to aluminium. The latter two factors favour Al-segregation to the surface. The most stable Ni:Al composition approaches 3:1 for larger clusters.     

Prognosis of non-Hodgkin's lymphomas in the Dresden district with special reference to combined radio-/chemotherapy

The total population affected with non-Hodgkin's lymphoma and treated by means of radiotherapy or combined radio-chemotherapy between 1960 and 1985 at the Medical Academy Dresden was analysed as to prognosis. 247 patients were classified according to the previous German scheme, 79 were subdivided on the basis of the recommendations laid down in the Kiel classification. The remission rates and survival curves achieved will stand out the comparison with international literature (remission rates of the low malignancy group amounted to 85.3 p.c. and those of the high malignancy group to 80.0 p.c.; the 5-years survival rates of the low malignancy group amounted to 61.9 p.c. and those of the high malignancy group to 41.7 p.c.). The influence of histology, clinical stage and involvement of organs is discussed on the basis of our results and informations obtained in literature. Our analysis confirms the high importance which must be attached to a common radiologic-internal outpatient-department for co-ordinating the diagnostic and therapeutical programme.     

Transcriptional regulation of the antioxidant protein 2 gene, a thiol-specific antioxidant, by lens epithelium-derived growth factor to protect cells from oxidative stress.

Antioxidant protein 2 (AOP2), a member of the newly defined family of thiol-specific antioxidant proteins, has been shown to remove H(2)O(2) and protect proteins and DNA from oxidative stress. Here we report that LEDGF is one of the regulatory factors for the AOP2 gene. We found that LEDGF bound to the heat shock element and to stress-related elements in the AOP2 promoter. It trans-activated expression of AOP2-CAT in COS-7 cells and lens epithelial cells overexpressing LEDGF. Mutations in the heat shock element and stress-related elements of the AOP2 promoter reduced LEDGF-dependent trans-activation. Lens epithelial cells showed a higher level of AOP2 mRNA in the presence of LEDGF. Cells overexpressing LEDGF exhibited a higher level of AOP2 protein, the level of which was directly related to the increase in cellular protection. Thus, LEDGF, by activating the AOP2 gene, protected and enhanced the survival of cells under oxidative stress.     

Immunity to Epstein-Barr virus in Hodgkin's disease preceded by infectious mononucleosis

A patient who developed Hodgkin''s disease four years after infectious mononucleosis had elevated serum antibody titres to Epstein-Barr virus and delayed hypersensitivity reactions to membrane antigens prepared from fresh autologous spleen, from spleen cells of another Hodgkin''s patient, and from cell lines known to carry the Epstein-Barr virus genome. Additional studies in more lymphoma patients will be needed to determine the significance of the reactivity against tumour and virus-associated antigens which has been documented in this patient.