2,605 research outputs found

    Investigations on the Problem of Moisture Absorption13; by Kevlar Fibres

    Get PDF
    Kevlar fibres are know, to have affinity for moisture. We have investigated (i) the effect of relative humidity (RH) of ambient atmosphere and ( ii ) the effect of crystallinity of fibres on the process of moisture uptake.13; For RH values ranging fran 3 to 80% variation of moisture content of initially dry fibres with time has been measured. It is found that saturation moisture content varies with RH value. Specimens in which crystallinity has been reduced by apropriate treatmrent exhibit a marked increase in moisture content.Experiments on the effect of soaking the fibres in water at 26xB0;C and 98xB0;C have also been carried out. The site of ITOisture absorption has been studied using X-ray of dry Kevlar 49 fibres and those with clifferent levels13; of misture content. The results suggest that water molecules do not enter the unit cell

    Macromolecular crystallography in India. A historical overview

    Get PDF
    India has a distinguished tradition in crystallography and structural biology. However, biological macromolecular crystallography in the country has had a somewhat delayed start on account of paucity of adequate funds and insufficient interactions between crystallographers and biochemists. Preliminary results in the area began to appear in the early eighties. The support provided by the Department of Science & Technology in the mid eighties under its thrust area programme for macromolecular crystallographic studies at the Molecular Biophysics Unit of the Indian Institute of Science gave a major impetus to work in the area. The Bangalore centre also came to be recognised as a national nucleus for the development of the area in the country. Since then, over the years, biological macromolecular crystallography has grown into a major activity in India encompassing nearly 20 institutions and close to twice as many research groups. It is also now at the centre stage of modern biological research in India. The problems addressed by biological crystallographers in the country span a wide spectrum and their efforts have made considerable international impact. Collective initiatives such as those involving microbial pathogens and structure-based inhibitor design have also begun to emerge

    Structural genomics of microbial pathogens - an Indian programme

    Get PDF
    Structural genomics, simply stated, seeks to determine the structures of all proteins coded by genomes of known sequence, using X-ray crystallography, NMR and bioinformatics. The known principles of protein architecture and the available information on the structural and functional classification of proteins, make this an approachable objective. The early excessive preoccupation with folds has now been substantially overcome. The emphasis is now on the determination of a collection of related proteins coded by a given genome or a set of similar proteins coded by different genomes. Taking advantage of the existing strengths in the country, a national programme on the structural genomics of microbial pathogens is being pursued. A major component of the programme is concerned with proteins from Mycobacterium tuberculosis. Comparative structural genomics of viruses forms another important component. Although not part of the concerted effort, structural studies on proteins from parasites are also gathering momentum. India has reasonably well-equipped laboratories for carrying out the programme. A major lacuna in the effort is caused by the absence of an Indian synchrotron X-ray facility. The results obtained so far in the programme have been encouraging. Particular attention is being paid to marry the requirements of quantity and quality. The overall objective of the programme is to advance our detailed understanding of selected microbial pathogens at the molecular level and to promote applications that flow from it where possible, under the overall umbrella provided by the genomics effort in the country

    Suprahelical arrangements of hydrogen bonds in peptide helices

    Get PDF
    corecore