Amido analogues of zincocenes and cadmocenes

The synthesis and characterisation of low-coordinate zinc and cadmium complexes of the sterically demanding 1,3,6,8-tetra-tert-butylcarbazol-9-yl ligand ((t)Bu(4)carb(-)) are reported. ((t)Bu(4)carb)(2)M (M = Zn 1; M = Cd 2) are the first examples of formally two-coordinate bis-carbazol-9-yl complexes of the Group 12 metals and 2 is the first crystallographically characterised two-coordinate amido complex of cadmium. The structure and bonding within these complexes are explored via a combination of X-ray crystallography and DFT calculations. The solid state structures for these zinc and cadmium complexes differ greatly from each other; not only do the steric demands of the peripheral tert-butyl substituents in these systems act to inhibit solvent coordination, but they also influence the coordination geometry around the metal centres.     

Representing quasi-orders by embeddability ordering of families of topological spaces

An elementary argument constructs, for each cardinal , a topological space whose subspaces, ordered by homeomorphic embeddability, can model every partial order on -many points. We show how to modify this procedure to deal also with quasi-orders (where the antisymmetry condition may fail), obtaining an initial estimate of the cardinality of the space then required.

     

On the infinity norm of the inverse of a class of toeplitz matrices of band width five

A useful theorem for precisely bounding the infinity norm of the inverse of a five-diagonal symmetric positive definite Toeplitz matrix is obtained.     

Magnetic properties of a novel family of ferrous cubanes

A novel family of paramagnetic tetranuclear ferrous cubanes is reported. Two complexes from this family are described and their magnetic properties are discussed in relation to their structures.     

Cleavability in Semigroups

The notion of cleavability (splittability) is observed to apply not only to topological spaces, where it was first developed, but to semigroups also. Several results of the form 'if a semigroup D is cleavable over a class of semigroups each of which has property P, then D also has property P' are derived, and some suggestions for further investigations are put forward.     

DNA vaccine containing the mycobacterial hsp65 gene prevented insulitis in MLD-STZ diabetes

Background  

Our group previously demonstrated that a DNA plasmid encoding the mycobacterial 65-kDa heat shock protein (DNA-HSP65) displayed prophylactic and therapeutic effect in a mice model for tuberculosis. This protection was attributed to induction of a strong cellular immunity against HSP65. As specific immunity to HSP60 family has been detected in arthritis, multiple sclerosis and diabetes, the vaccination procedure with DNA-HSP65 could induce a cross-reactive immune response that could trigger or worsen these autoimmune diseases.