382 research outputs found

    FEL research and development at STFC Daresbury laboratory

    Get PDF
    In this paper we present an overview of current and proposed FEL developments at STFC Daresbury Laboratory in the UK. We discuss progress on the ALICE IR-FEL since first lasing in October 2010, covering the optimisation of the FEL performance, progress on the demonstration of a single shot cross correlation experiment and the results obtained so far with a Scanning Near-Field Optical Microscopy beamline. We discuss a proposal for a 250 MeV single pass FEL test facility named CLARA to be built at Daresbury and dedicated to research for future light source applications. Finally we present a brief overview of other recent research highlights

    Circuit Quantum Electrodynamics with a Spin Qubit

    Full text link
    Circuit quantum electrodynamics allows spatially separated superconducting qubits to interact via a "quantum bus", enabling two-qubit entanglement and the implementation of simple quantum algorithms. We combine the circuit quantum electrodynamics architecture with spin qubits by coupling an InAs nanowire double quantum dot to a superconducting cavity. We drive single spin rotations using electric dipole spin resonance and demonstrate that photons trapped in the cavity are sensitive to single spin dynamics. The hybrid quantum system allows measurements of the spin lifetime and the observation of coherent spin rotations. Our results demonstrate that a spin-cavity coupling strength of 1 MHz is feasible.Comment: Related papers at http://pettagroup.princeton.edu

    Exercise-induced release of troponin.

    Get PDF
    It is well established that regular physical activity reduces cardiovascular disease risk; however, numerous studies have demonstrated postexercise elevations in cardiac troponin (cTn), indicative of cardiac injury in apparently healthy individuals. The prevalence of these findings in different exercise settings and population groups, as well as potential underlying mechanisms and clinical significance of exercise-induced cTn release are not yet quite determined. The present review will discuss the cTn response to exercise in light of developing cTn assays and the correlation between postexercise cTn release and cardiac function. Additionally, recent data regarding the potential link between strenuous endurance exercise and its relationship with unfavorable cardiac effects in athletes, as well as the management of patients presenting at emergency care after sport events will be briefly reviewed

    Early Life Socioeconomic Circumstance and Late Life Brain Hyperintensities : A Population Based Cohort Study

    Get PDF
    Funding: Image acquisition and image analysis for this study was funded by the Alzheimer's Research Trust (now Alzheimer's Research UK). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments The authors would like to thank the participants of the Aberdeen 1936 Birth Cohort (ABC36), without whom this research would not have been possible.Peer reviewedPublisher PD

    Quantum Acoustics with Surface Acoustic Waves

    Full text link
    It has recently been demonstrated that surface acoustic waves (SAWs) can interact with superconducting qubits at the quantum level. SAW resonators in the GHz frequency range have also been found to have low loss at temperatures compatible with superconducting quantum circuits. These advances open up new possibilities to use the phonon degree of freedom to carry quantum information. In this paper, we give a description of the basic SAW components needed to develop quantum circuits, where propagating or localized SAW-phonons are used both to study basic physics and to manipulate quantum information. Using phonons instead of photons offers new possibilities which make these quantum acoustic circuits very interesting. We discuss general considerations for SAW experiments at the quantum level and describe experiments both with SAW resonators and with interaction between SAWs and a qubit. We also discuss several potential future developments.Comment: 14 pages, 12 figure

    Synthesis of some nucleosides derivatives from L- rhamnose with expected biological activity

    Get PDF
    Practical procedures for production of variously blocked compounds from L-rhamnose have been developed. These compounds are highly useful as indirect β-L-rhamnosyl donors. This approach represents a new method for the synthesis of aromatic nucleoside analogues and the synthesis of (3S, 4S, 5S, 6R) 3, 4, 5-triacetoxy-2-methyl-7,9-diaza-1-oxa-spiro [4,5]decane-10-one-8-thione (7)

    Generation and Characterization of a Novel Recombinant Antibody Against 15-Ketocholestane Isolated by Phage-Display

    Get PDF
    The employment of monoclonal antibodies (Mabs) to identify disease-associated biomarkers in clinical samples represents the underlying principle for many diagnostic tests. To date, these have been principally developed for protein targets with few reported applications for lipids due to their hydrophobicity and poor immunogenicity. Oxysterols represent a family of lipids implicated in diverse human diseases where Mab-based detection assays could have a profound effect on their utility as clinical biomarkers. These are usually identified in patients’ samples by mass- spectrometry based approaches. Here, we describe an antibody phage-library based screening methodology for generating a recombinant monoclonal antibody (RAb) targeting the oxysterol-15-ketocholestane (15-KA), a lipid implicated in multiple sclerosis and Autoimmune Encephalomyelitis (EAE). The antibody is highly specific for 15-KA and shows little or no binding activity for other closely related oxysterols. We employ RAb2E9 to address the controversy over whether 15-KA is a true biomarker for MS/EAE and show that 15-KA is undetectable in serum taken from mice with EAE using antibody based detection methodologies; a finding confirmed by mass-spectrometry analysis. This study demonstrates the technical feasibility of using phage display to isolate highly specific antibodies against poorly immunogenic, small molecule lipids

    Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses

    Get PDF
    The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined

    High Prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae Detected in the Human Gut Using an Improved DNA Detection Protocol

    Get PDF
    Background: The low and variable prevalence of Methanobrevibacter smithii and Methanosphaera stadtmanae DNA in human stool contrasts with the paramount role of these methanogenic Archaea in digestion processes. We hypothesized that this contrast is a consequence of the inefficiencies of current protocols for archaeon DNA extraction. We developed a new protocol for the extraction and PCR-based detection of M. smithii and M. stadtmanae DNA in human stool. Methodology/Principal Findings: Stool specimens collected from 700 individuals were filtered, mechanically lysed twice, and incubated overnight with proteinase K prior to DNA extraction using a commercial DNA extraction kit. Total DNA was used as a template for quantitative real-time PCR targeting M. smithii and M. stadtmanae 16S rRNA and rpoB genes. Amplification of 16S rRNA and rpoB yielded positive detection of M. smithii in 95.7% and M. stadtmanae in 29.4% of specimens. Sequencing of 16S rRNA gene PCR products from 30 randomly selected specimens ( 15 for M. smithii and 15 for M. stadtmanae) yielded a sequence similarity of 99-100% using the reference M. smithii ATCC 35061 and M. stadtmanae DSM 3091 sequences. Conclusions/Significance: In contrast to previous reports, these data indicate a high prevalence of the methanogens M. smithii and M. stadtmanae in the human gut, with the former being an almost ubiquitous inhabitant of the intestinal microbiome

    The reliability of methods to estimate the number and size of human motor units and their use with large limb muscles

    Get PDF
    Purpose: Current methods for estimating muscle motor unit (MU) number provide values which are remarkably similar for muscles of widely differing size, probably because surface electrodes sample from similar and relatively small volumes in each muscle. We have evaluated an alternative means of estimating MU number that takes into account differences in muscle size. Methods: Intramuscular motor unit potentials (MUPs) were recorded and muscle cross-sectional area (CSA) was measured using MRI to provide a motor unit number estimate (iMUNE). This was compared to the traditional MUNE method, using compound muscle action potentials (CMAP) and surface motor unit potentials (sMUPs) recorded using surface electrodes. Data were collected from proximal and distal regions of the vastus lateralis (VL) in young and old men while test–retest reliability was evaluated with VL, tibialis anterior and biceps brachii. Results: MUPs, sMUPs and CMAPs were highly reliable (r = 0.84–0.91). The traditional MUNE, based on surface recordings, did not differ between proximal and distal sites of the VL despite the proximal CSA being twice the distal CSA. iMUNE, however, gave values that differed between young and old and were proportional to the muscle size. Conclusion: When evaluating the contribution that MU loss makes to muscle atrophy, such as in disease or ageing, it is important to have a method such as iMUNE, which takes into account any differences in total muscle size
    corecore