2,882 research outputs found

    Peptides as potent antimicrobials tethered to a solid surface: Implications for medical devices

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    Medical devices are an integral part of therapeutic management; despite their importance, they carry a significant risk of microbial infection. Bacterial attachment to a medical device is established by a single, multiplying organism, leading to subsequent biofilm formation. To date, no preventative measures have impacted the incidence of device-related infection. We report the bidirectional covalent coupling of an engineered cationic antimicrobial peptide (eCAP), WLBU2, to various biological surfaces is accomplished. These surfaces included (i) a carbohydrate-based gel matrix, (ii) a complex polymeric plastic bead, and (iii) a silica-calcium phosphate nanocomposite associated with bone reconstruction. WLBU2-conjugated surfaces are shown to retain potent antimicrobial activity related to bacterial surface adhesion. This study provides proof of principle that covalently coating laboratory and bone-regenerating materials with eCAPs has the potential for decreasing infection rates of implanted devices. These findings have important consequences to the patient management component of our current health care technology

    HST morphologies of local Lyman break galaxy analogs I: Evidence for starbursts triggered by merging

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    Heckman et al. (2005) used the Galaxy Evolution Explorer (GALEX) UV imaging survey to show that there exists a rare population of nearby compact UV-luminous galaxies (UVLGs) that closely resembles high redshift Lyman break galaxies (LBGs). We present HST images in the UV, optical, and Ha, and resimulate them at the depth and resolution of the GOODS/UDF fields to show that the morphologies of UVLGs are also similar to those of LBGs. Our sample of 8 LBG analogs thus provides detailed insight into the connection between star formation and LBG morphology. Faint tidal features or companions can be seen in all of the rest-frame optical images, suggesting that the starbursts are the result of a merger or interaction. The UV/optical light is dominated by unresolved (~100-300 pc) super starburst regions (SSBs). A detailed comparison with the galaxies Haro 11 and VV 114 at z=0.02 indicates that the SSBs themselves consist of diffuse stars and (super) star clusters. The structural features revealed by the new HST images occur on very small physical scales and are thus not detectable in images of high redshift LBGs, except in a few cases where they are magnified by gravitational lensing. We propose, therefore, that LBGs are mergers of gas-rich, relatively low-mass (~10^10 Msun) systems, and that the mergers trigger the formation of SSBs. If galaxies at high redshifts are dominated by SSBs, then the faint end slope of the luminosity function is predicted to have slope alpha~2. Our results are the most direct confirmation to date of models that predict that the main mode of star formation in the early universe was highly collisional.Comment: 32 pages, 15 figures. ApJ In pres

    Extracellular volume fraction is associated with B-type natriuretic peptide in hypertrophic cardiomyopathy

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    Hypertrophic cardiomyopathy is a common cardiovascular genetic disease characterized by sarcomeric gene mutations which lead to findings of cardiac hypertrophy, myocyte disarray, and fibrosis. While late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) detects focal, macroscopic regions of replacement fibrosis non-invasively, novel T1 CMR measurement techniques including extracellular volume fraction (ECV) diffuse interstitial fibrosis throughout the myocardium. Plasma B-type natriuretic peptide levels are often elevated in situations of increased wall tension and volume overload. Given that such states may be associated with myocardial fibrosis, and because BNP levels provide independent prognostic insight in HCM, we sought to determine the association between BNP and ECV measurement by CMR

    Ex vivo loading of trussed implants for spine fusion induces heterogeneous strains consistent with homeostatic bone mechanobiology

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    A truss structure was recently introduced as an interbody fusion cage. As a truss system, some of the connected elements may be in a state of compression and others in tension. This study aimed to quantify both the mean and variance of strut strains in such an implant when loaded in a simulated fusion condition with vertebral body or contoured plastic loading platens ex vivo. Cages were each instrumented with 78 fiducial spheres, loaded between platens (vertebral body or contoured plastic), imaged using high resolution micro-CT, and analyzed for deformation and strain of each of the 221 struts. With repeated loading of a cage by vertebral platens, the distribution (variance, indicated by SD) of strut strains widened from 50N control (4±114ΌΔ, mean±SD) to 1000N (-23±273ΌΔ) and 2000N (-48±414ΌΔ), and between 1000N and 2000N. With similar loading of multiple cages, the strain distribution at 2000N (23±389ΌΔ) increased from 50N control. With repeated loading by contoured plastic platens, induced strains at 2000N had a distribution similar to that induced by vertebral platens (84±426ΌΔ). In all studies, cages exhibited increases in strut strain amplitude when loaded from 50N to 1000N or 2000N. Correspondingly, at 2000N, 59-64% of struts exhibited strain amplitudes consistent with mechanobiologically-regulated bone homeostasis. At 2000N, vertically-oriented struts exhibited deformation of -2.87±2.04Όm and strain of -199±133ΌΔ, indicating overall cage compression. Thus, using an ex vivo 3-D experimental biomechanical analysis method, a truss implant can have strains induced by physiological loading that are heterogeneous and of amplitudes consistent with mechanobiological bone homeostasis

    Willingness of Hong Kong healthcare workers to accept pre-pandemic influenza vaccination at different WHO alert levels: two questionnaire surveys

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    Objective To assess the acceptability of pre-pandemic influenza vaccination among healthcare workers in public hospitals in Hong Kong and the effect of escalation in the World Health Organization’s alert level for an influenza pandemic

    Capacity building for dementia care in community care services: a mixed methods approach

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    Background The prevalence of dementia is surging that results in huge service demand in the community care services. Dementia care competence of staff working in these settings is fundamental of the care quality. This project aims to examine the effects of staff training on their competence for the anticipated challenges in dementia care and explore how the training influence their care practices. Methods This study adopted a mixed methods triangulation design, including a prospective multi-center study with pre-test post-test evaluations and a narrative analysis of the participants’ reflective essays. Seventeen experienced health and social care professionals were trained as trainers at the Dementia Services Development Centre of the University of Stirling, UK. The trainers provided local facilitator training to staff members by using training materials that were culturally adapted to the local context. The facilitators were required to deliver 12 two-hour in-service training sessions for 6 months to their colleagues in a small group format in their respective workplace. Eventually a total of 1347 staff members from community care centers, day care centers, outreach teams and care homes of 70 non-government organizations in Hong Kong participated in the study between April 2017 and December 2018. Validated instruments were used to measure knowledge, attitude, sense of competence in dementia care and job satisfaction at the baseline and at 12-month follow-up. All participants were required to write a reflective essay to describe their experiences in dementia care by the end of the training. Results A total of 1264 participants, including 195 facilitators and 1069 learners, completed all assessment were included for analysis. Significant improvements were observed in all outcomes at the 12-month follow-up assessment (Ps ≀ .001). The magnitude of improvements in attitudes was the largest. The findings also showed that the effects of the training program significantly varied across different groups of learners in terms of age, occupation, work and training experience. Conclusions This community-wide large-scale project provided evidence that the train-the-trainer model and reflective learning are effective means to facilitate situated learning that promote awareness and understanding of dementia, and consequently enhance sustainability of changes in care practices
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