1,486 research outputs found

    Searching the World-Wide-Web using nucleotide and peptide sequences

    Get PDF
    *Background:* No approaches have yet been developed to allow instant searching of the World-Wide-Web by just entering a string of sequence data. Though general search engines can be tuned to accept ‘processed’ queries, the burden of preparing such ‘search strings’ simply defeats the purpose of quickly locating highly relevant information. Unlike ‘sequence similarity’ searches that employ dedicated algorithms (like BLAST) to compare an input sequence from defined databases, a direct ‘sequence based’ search simply locates quick and relevant information about a blunt piece of nucleotide or peptide sequence. This approach is particularly invaluable to all biomedical researchers who would often like to enter a sequence and quickly locate any pertinent information before proceeding to carry out detailed sequence alignment. 

*Results:* Here, we describe the theory and implementation of a web-based front-end for a search engine, like Google, which accepts sequence fragments and interactively retrieves a collection of highly relevant links and documents, in real-time. e.g. flat files like patent records, privately hosted sequence documents and regular databases. 

*Conclusions:* The importance of this simple yet highly relevant tool will be evident when with a little bit of tweaking, the tool can be engineered to carry out searches on all kinds of hosted documents in the World-Wide-Web.

*Availability:* Instaseq is free web based service that can be accessed by visiting the following hyperlink on the WWW
http://instaseq.georgetown.edu 
&#xa

    Modulating Integrin Ī±IIbĪ²3 Activity through Mutagenesis of Allosterically Regulated Intersubunit Contacts

    Get PDF
    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Biochemistry, copyright Ā© American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.biochem.9b00430.Integrin Ī±IIbĪ²3, a transmembrane heterodimer, mediates platelet aggregation when it switches from an inactive to an active ligand-binding conformation following platelet stimulation. Central to regulating Ī±IIbĪ²3 activity is the interaction between the Ī±IIb and Ī²3 extracellular stalks, which form a tight heterodimer in the inactive state and dissociate in the active state. Here, we demonstrate that alanine replacements of sensitive positions in the heterodimer stalk interface destabilize the inactive conformation sufficiently to cause constitutive Ī±IIbĪ²3 activation. To determine the structural basis for this effect, we performed a structural bioinformatics analysis and found that perturbing intersubunit contacts with favorable interaction geometry through substitutions to alanine quantitatively accounted for the degree of constitutive Ī±IIbĪ²3 activation. This mutational study directly assesses the relationship between favorable interaction geometry at mutation-sensitive positions and the functional activity of those mutants, giving rise to a simple model that highlights the importance of interaction geometry in contributing to the stability between proteinā€“protein interactions.NIH P01 HL40387NIH R35 GM122603National Science Foundation 1709506National Science Foundation 165011

    Liquid phase blending of metal-organic frameworks.

    Get PDF
    The liquid and glass states of metal-organic frameworks (MOFs)Ā have recently become of interest due to the potential for liquid-phase separations and ion transport, alongside the fundamental nature of the latter as a new, fourth category of melt-quenched glass. Here we show that the MOF liquid state can be blended with another MOF component, resulting in a domain structured MOF glass with a single, tailorable glass transition. Intra-domain connectivity and short range order is confirmed by nuclear magnetic resonance spectroscopy and pair distribution function measurements. The interfacial binding between MOF domains in the glass state is evidenced by electron tomography, and the relationship between domain size and Tg investigated. Nanoindentation experiments are also performed to place this new class of MOF materials into context with organic blends and inorganic alloys

    Optimised power harvesting by controlling the pressure applied to molecular junctions

    Get PDF
    A major potential advantage of creating thermoelectric devices using self-assembled molecular layers is their mechanical flexibility. Previous reports have discussed the advantage of this flexibility from the perspective of facile skin attachment and the ability to avoid mechanical deformation. In this work, we demonstrate that the thermoelectric properties of such molecular devices can be controlled by taking advantage of their mechanical flexibility. The thermoelectric properties of self-assembled monolayers (SAMs) fabricated from thiol terminated molecules were measured with a modified AFM system, and the conformation of the SAMs was controlled by regulating the loading force between the organic thin film and the probe, which changes the tilt angle at the metal-molecule interface. We tracked the thermopower shift vs. the tilt angle of the SAM and showed that changes in both the electrical conductivity and Seebeck coefficient combine to optimize the power factor at a specific angle. This optimization of thermoelectric performance via applied pressure is confirmed through the use of theoretical calculations and is expected to be a general method for optimising the power factor of SAMs

    Oral steroids for the resolution of otitis media with effusion (OME) in children (OSTRICH): study protocol for a randomised controlled trial

    Get PDF
    Background Otitis media with effusion (OME) is an accumulation of fluid in the middle ear affecting about 80% of children by the age of 4 years. While OME usually resolves spontaneously, it can affect speech, behaviour and development. Children with persistent hearing loss associated with OME are usually offered hearing aids or insertion of ventilation tubes through the tympanic membrane. Oral steroids may be a safe and effective treatment for OME, which could be delivered in primary care. It has the potential to benefit large numbers of children and reduce the burden of care on them and on health services. However, previous trials have either been too small with too short a follow up period, or of too poor quality to give a definite answer. The aim of the OSTRICH trial is to determine if a short course of oral steroids improves the hearing of children with OME in the short and longer term. Methods/Design 380 participants (children aged 2-8 years) are recruited from Hospital Ear, Nose and Throat departments in Wales and England. A trained clinician seeks informed consent from parents of children with symptoms attributable to OME for at least 3 months and with confirmed bilateral hearing loss at study entry. Participants are randomised to a course of oral steroid or a matched placebo for one week. Outcomes include audiometry, tympanometry and otoscopy assessments, symptoms, adverse effects, functional health status, quality of life, resource use and cost effectiveness. Participants are followed up at 5 weeks, and at 6 and 12 months after the day of randomisation. The primary outcome is audiometry-confirmed satisfactory hearing at 5 weeks. Discussion There is an important evidence gap regarding clinical and cost effectiveness of short courses of oral steroid treatment for OME. Identifying an effective, safe, non-surgical intervention for OME in children for use in primary care would be of great benefit to children, their families and the NHS

    Quantitative association tests of immune responses to antigens of Mycobacterium tuberculosis: a study of twins in West Africa.

    No full text
    There is now considerable evidence that host genetic factors are important in determining the outcome of infection with Mycobacterium tuberculosis (MTB). The aim of this study was to assess the role of several candidate genes in the variation observed in the immune responses to MTB antigens. In-vitro assays of T-cell proliferation, an in-vivo intradermal delayed hypersensitivity response; cytokine and antibody secretions to several mycobacterial peptide antigens were assessed in healthy, but exposed, West African twins. Candidate gene polymorphisms were typed in the NRAMP1, Vitamin D receptor, IL10, IL4, IL4 receptor and CTLA-4 genes. Variants of the loci IL10 (-1082 G/A), CTLA-4 (49 A/G) and the IL4 receptor (128 A/G) showed significant associations with immune responses to several antigens. T-cell proliferative responses and antibody responses were reduced, TNF-alpha responses were increased for subjects with the CTLA-4 G allele. The T-cell proliferative responses of subjects with IL10 GA and GG genotypes differed significantly. IL4 receptor AG and GG genotypes also showed significant differences in their T-cell proliferative responses to MTB antigens. These results yield a greater understanding of the genetic mechanisms that underlie the immune responses in tuberculosis and have implications for the design of therapeutic interventions
    • ā€¦
    corecore