Directing the structures of silver-antimony sulphides: a new topological variant of the [Ag5Sb3S8](2-) double layer

A new silver-antimony sulphide, [C6H20N4][Ag5Sb3S8], has been synthesised solvothermally in the presence of triethylenetetramine and characterised by single-crystal X-ray diffraction, thermogravimetry and elemental analysis. The compound crystallises in the space group P2(1)/m (a = 6.2778(7), b = 15.8175(16) and c = 12.4617(15) angstrom and beta = 104.561(5)degrees) and adopts a structure in which honeycomb-like sheets of fused six-membered silver-antimony-sulphide rings are linked through Ag-S bonds to form double layers. The idealised structure can be considered to be derived from that of antifluorite and represents a second structure type for the [Ag5Sb3S8](2-) double layer. (c) 2005 Elsevier Inc. All rights reserved.

Templated synthesis of the novel layered silver-antimony Sulfides [H3NCH2CH2NH2][Ag2SbS3] and [H3NCH2CH2NH2](2)[Ag5Sb3S8]

Two new silver-antimony sulfides, [C2H9N2][Ag2SbS3] (1) and [C2H9N2](2)[Ag5Sb3S8] (2), have been prepared solvothermally in the presence of ethylenediamine and characterized by single-crystal X-ray diffraction, thermogravimetry, and elemental analysis. Compound 1 crystallizes in the space group Pn (a = 6.1781(1) Angstrom, b =11.9491(3) Angstrom, c = 6.9239(2) Angstrom, =111.164(1)degrees) and 2 in the space group Pm (a = 6.2215(2) Angstrom, b = 15.7707(7) Angstrom, c = 11.6478(5) Angstrom, beta = 92.645(2)degrees). The structure of 1 consists of chains of fused five-membered Ag2SbS2 rings linked to form layers, between which the template molecules reside. Compound 2 contains honeycomb-like sheets of fused silver-antimony-sulfide six-membered rings linked to form double layers. The idealized structure can be considered to be an ordered defect derivative of that of lithium bismuthide, Li3Bi, and represents a new solid-state structure type.

Ultra-thin porous silica coated silver-platinum alloy nano-particle as a new catalyst precursor

Templated sol-gel encapsulation of surfactant-stabilised micelles containing metal precursor(s) with ultra-thin porous silica coating allows solvent extraction of organic based stabiliser from the composites in colloidal state hence a new method of preparing supported alloy catalysts using the inorganic silica-stabilised nano-sized, homogenously mixed, silver - platinum (Ag-Pt) colloidal particles is reported.

Nutrition Society Silver Medal Lecture Nutrigenetics and personalised nutrition: how far have we progressed and are we likely to get there?

Nutrigenetics and personalised nutrition are components of the concept that in the future genotyping will be used as a means of defining dietary recommendations to suit the individual. Over the last two decades there has been an explosion of research in this area, with often conflicting findings reported in the literature. Reviews of the literature in the area of apoE genotype and cardiovascular health, apoA5 genotype and postprandial lipaemia and perilipin and adiposity are used to demonstrate the complexities of genotype-phenotype associations and the aetiology of apparent between-study inconsistencies in the significance and size of effects. Furthermore, genetic research currently often takes a very reductionist approach, examining the interactions between individual genotypes and individual disease biomarkers and how they are modified by isolated dietary components or foods. Each individual possesses potentially hundreds of 'at-risk' gene variants and consumes a highly-complex diet. In order for nutrigenetics to become a useful public health tool, there is a great need to use mathematical and bioinformatic tools to develop strategies to examine the combined impact of multiple gene variants on a range of health outcomes and establish how these associations can be modified using combined dietary strategies.

Greek, Latin, and the Indian Civil Service

This is a slightly revised version of an article first published in the Cambridge Classical Journal, vol. 51 (2005), pp. 35-71.