183 research outputs found
Marine geophysical studies between northwest Scotland and the Faeroe plateau
A marine geophysical survey of the northern Rockall Trough including the Banks to the north and northwest, the Wyville-Thomson Rise and the Hebridean continental shelf was carried out in 1970 and 1971,Gravity, magnetic and seismic reflection data indicates that the central Rockall Trough is underlain by about 5 km of sediment overlying a normal oceanic crust. The sedimentary thickness decreases to about 3 km and the crust becomes anomalously thick at the northern end of the Trough. Gravity and magnetic interpretation suggests that the Faeroe-Shetland channel is also underlain by anomalously thick oceanic crust. Gravity interpretation indicates that George Bligh, Bill Bailey's and Faeroe Bank are underlain by crust of continental thickness. The Wyville-Thomson Rise, which connects Faeroe Bank to the Scottish continental margin, is composed of two basement ridges of pre-Lower Oligocene age shrouded by sediments up to 1.5 km thick. The north easterly ridge is continuous from the Bank to the continental margin but the south westerly ridge terminates about 50 km from the margin. Magnetic and gravity evidence indicates that the ridges are composed of igneous material and that crustal thickening occurs beneath the ridges. An intrusive complex of unknown age lies beneath the southwest flank of the Rise. Gravity, magnetic and bathymetric interpretation indicates that the Hebridean continental shelf is underlain by Lewisian basement. Gravity and magnetic interpretation indicates that a NNE-SSW trending sedimentary basin about 1.5 km deep and with a partial covering of Tertiary lavas lies between Lewis and the Flannan Isles. Tertiary intrusive complexes, recognisable by their magnetic, gravitational and bathymetric effects, are present beneath St. Kilda, below the continental slope 75 km northwest of St. Kilda and beneath the shelf kO km north-northwest of the Butt of Lewis
Resveratrol Inhibits Wound-healing and Lens Fibrosis: A Putative Candidate for Posterior Capsule Opacification Prevention
Purpose : Posterior capsule opacification (PCO) is a common complication of cataract surgery. In addition to improved surgical methods and IOL designs it is likely additional agents will be needed to improve patient outcomes. Presently no pharmacological agent is in clinical use to prevent PCO. Here we investigate the putative ability of resveratrol (RESV), a naturally occurring polyphenol, as a therapeutic agent. Methods : The human lens epithelial cell line FHL124, a human lens capsular bag model and central anterior epithelium were employed as experimental systems. Standard culture was in 5% FCS EMEM. 10ng/ml Transforming growth factor-2 (TGFβ2) was used to induce fibrotic changes. A scratch wound assay was used to measure cell migration and the patch assay employed to assess matrix contraction by FHL124 cells. Protein expression was assessed by immunocytochemistry and western blot and gene expression by QRT-PCR. In capsular bags, cell growth across the posterior lens capsule, capsular wrinkling and EMT were determined by image analysis. Results : In FHL124 cells, addition of 30 μM RESV significantly impeded cell migration in a wound healing assay. RESV significantly inhibited TGFβ2-induced expression of the myofibroblast marker alpha-smooth muscle actin (α-SMA) at both the message and protein level as well as significantly inhibiting matrix contraction induced by TGFβ2. In human capsular bags, 30 μM RESV significantly inhibited cell growth. TGFβ2-induced α-SMA expression and capsular wrinkling were also significantly inhibited by RESV treatment. RESV significantly supressed expression of TGFβ2-induced genes associated with fibrotic disease, including matrix metalloproteinase-2 in FHL124 cells, capsular bags and central anterior epithelium. Conclusions : RESV can counter PCO related physiological events in two human lens model systems. RESV therefore has the potential to be used as a candidate agent for the prevention of PCO, which in turn could benefit millions of cataract patients
An in vitro human lens capsular bag model adopting a graded culture regime to assess putative impact of IOLs on PCO formation
Purpose: To develop a culture regime for the in vitro human lens capsular bag model that better reflects clinical events following cataract surgery and to use this refined model to evaluate the putative impact of IOLs on PCO formation. Methods: Capsulorhexis and lens extraction were performed on human donor eyes to generate capsular bags attached to the ciliary body by the zonules. Preparations were secured by pinning the ciliary body to a silicone ring and maintaining in 6 mL serum-free EMEM for 28 days or in a graded culture system (Days 1-3, 5% Human serum and 10ng/ml TGFβ2; Days 4-7, 2% Human serum and 1ng/ml TGFβ2; Days 8-14, 1% Human serum and 0.1ng/ml TGFβ2; Days 15-28, Serum-free EMEM), which better mimics clinical changes. Preparations were monitored with phase-contrast and modified-dark-field microscopy. Cell coverage and light scatter were quantified using image analysis software. The trans-differentiation marker, α- SMA and matrix component, fibronectin were assessed by immunocytochemistry. To assess IOLs in the model, Alcon Acrysof or Hoya Vivinex IOLs were implanted in match-paired capsular bags. Results: Match-paired experiments showed that graded culture enhanced growth, facilitated matrix contraction, increased trans-differentiation and promoted matrix deposition relative to serum-free culture. The graded culture protocol was applied to match-paired bags implanted with a Hoya Vivinex or an Alcon Acrysof IOL. The Vivinex demonstrated a lag in growth across the posterior capsule. However, by day 28, coverage was similar, but light-scatter was greater with Acrysof implanted. Cell growth on the Acrysof IOL anterior surface was significantly greater than Vivinex. Conclusions: The graded culture human capsular bag model serves as an excellent system to evaluate and develop intraocular lenses. The Hoya Vivinex IOL showed an overall better level of performance against post-surgical wound-healing and PCO than the Alcon Acrysof using this model
Propagation of model form uncertainty for thermal hydraulics using RANS turbulence models in Drekar.
Practice size, caseload, deprivation and quality of care of patients with coronary heart disease, hypertension and stroke in primary care: national cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Reports of higher quality care by higher-volume secondary care providers have fuelled a shift of services from smaller provider units to larger hospitals and units. In the United Kingdom, most patients are managed in primary care. Hence if larger practices provide better quality of care; this would have important implications for the future organization of primary care services. We examined the association between quality of primary care for cardiovascular disease achieved by general practices in England and Scotland by general practice caseload, practice size and area based deprivation measures, using data from the New General Practitioner (GP) Contract.</p> <p>Methods</p> <p>We analyzed data from 8,970 general practices with a total registered population of 55,522,778 patients in England and Scotland. We measured practice performance against 26 cardiovascular disease (coronary heart disease, left ventricular disease, and stroke) Quality and Outcomes Framework (QOF) indicators for patients on cardiovascular disease registers and linked this with data on practice characteristics and census data.</p> <p>Results</p> <p>Despite wide variations in practice list sizes and deprivation, the prevalence of was remarkably consistent, (coronary heart disease, left ventricular dysfunction, hypertension and cerebrovascular disease was 3.7%; 0.45%; 11.4% and 1.5% respectively). Achievement in quality of care for cardiovascular disease, as measured by QOF, was consistently high regardless of caseload or size with a few notable exceptions: practices with larger list sizes, higher cardiovascular disease caseloads and those in affluent areas had higher achievement of indicators requiring referral for further investigation. For example, small practices achieved lower scores 71.4% than large practices 88.6% (P < 0.0001) for referral for exercise testing and specialist assessment of patients with newly diagnosed angina.</p> <p>Conclusion</p> <p>The volume-outcome relationship found in hospital settings is not seen between practices in the UK in management of cardiovascular disorders in primary care. Further work is warranted to explain apparently poorer quality achievement in some aspects of cardiovascular management relating to initial diagnosis and management among practices in deprived areas, smaller practices and those with a smaller caseload.</p
- …