Can guidelines improve referral to elective surgical specialties for adults? A systematic review

Aim To assess effectiveness of guidelines for referral for elective surgical assessment. Method Systematic review with descriptive synthesis. Data sources Medline, EMBASE, CINAHL and Cochrane database up to 2008. Hand searches of journals and websites. Selection of studies Studies evaluated guidelines for referral from primary to secondary care, for elective surgical assessment for adults. Outcome measures Appropriateness of referral (usually measured as guideline compliance) including clinical appropriateness, appropriateness of destination and of pre-referral management (eg, diagnostic investigations), general practitioner knowledge of referral appropriateness, referral rates, health outcomes and costs. Results 24 eligible studies (5 randomised control trials, 6 cohort, 13 case series) included guidelines from UK, Europe, Canada and the USA for referral for musculoskeletal, urological, ENT, gynaecology, general surgical and ophthalmological conditions. Interventions varied from complex (“one-stop shops”) to simple guidelines. Four randomized control trials reported increases in appropriateness of pre-referral care (diagnostic investigations and treatment). No evidence was found for effects on practitioner knowledge. Mixed evidence was reported on rates of referral and costs (rates and costs increased, decreased or stayed the same). Two studies reported on health outcomes finding no change. Conclusions Guidelines for elective surgical referral can improve appropriateness of care by improving prereferral investigation and treatment, but there is no strong evidence in favour of other beneficial effects

A Homogenization Approach for Turbulent Channel Flows over Porous Substrates: Formulation and Implementation of Effective Boundary Conditions

The turbulent flow through a plane channel bounded by a single permeable wall is considered; this is a problem of interest since a carefully chosen distribution of grains and voids in the porous medium can result in skin friction reduction for the flow in the channel. In the homogenization approach followed here, the flow is not resolved in the porous layer, but an effective velocity boundary condition is developed (and later enforced) at a virtual interface between the porous bed and the channel flow. The condition is valid up to order two in terms of a small gauge factor, the ratio of microscopic to macroscopic length scales; it contains slip coefficients, plus surface and bulk permeability coefficients, which arise from the solution of microscale problems solved in a representative elementary volume. Using the effective boundary conditions, free of empirical parameters, direct numerical simulations are then performed in the channel, considering a few different porous substrates. The results, examined in terms of mean values and turbulence statistics, demonstrate the drag-reducing effects of porous substrates with streamwise-preferential alignment of the solid grains

Heavy metals burden of Keenjhar Lake, District Thatta, Sindh, Pakistan

Detection of heavy metals (HMs) content from Keenjhar Lake water was carried out monthly from January to December, 2003. Zinc, chromium, copper, iron, manganese, nickel and cadmium were analyzed by dual mode of analytical methods flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry (FAAS and ETAAS) by multi element standard solution. The concentrations of zinc, chromium, copper, iron, manganese Nickel and cadmium were 1.4 to 104.3 μgL-1, 1.28 to 4.9 μgL-1, 0.6 to 7.3 μgL-1, 2 to 45.6 μgL-1, 0.2 to 6.7 μgL-1, 3.54 to 39.5 μgL-1 and 1.0 to 4.3 μgL-1, respectively. Zn2+, Cr+, Cu2+, Fe2+ and Mn2+ concentrations were recorded lower than those of permissible limits, whereas Ni+ and Cd+ were higher than those of permissible limits recommended by WHO (2004).Key words: Heavy metals, Keenjhar Lake, toxicity

Giants and loops in beta-deformed theories

We study extended objects in the gravity dual of the N=1 beta-deformation of N=4 Super Yang-Mills theory. We identify probe brane configurations corresponding to giant gravitons and Wilson loops. In particular we identify a new class of objects, given by D5-branes wrapped on a two-torus with a world-volume gauge field strength turned on along the torus. These appear when the deformation parameter assumes a rational value and the gauge theory spectrum has additional branches of vacua. We give an interpretation of the new D5-brane dual giant gravitons in terms of rotating vacuum expectation values in these additional branches.Comment: 26 pages; typos corrected, published versio

Comparison of outcomes following transfemoral versus trans-subclavian approach for transcatheter aortic valve Implantation: a meta-analysis

Background The subclavian artery is an alternative access route for transcatheter aortic valve implantation (TAVI), with a potential advantage in patients unsuitable for traditional access routes such as the femoral artery. This study aimed to determine the safety and efficacy of the trans-subclavian (TSc) compared to the trans-femoral (TF) approach. Methods A systematic review was conducted on two online databases: Embase and Medline. The initial search returned 508 titles. Nine observational studies were included: n = 2938 patients (2382 TF and 556 TSc). Results Both TSc and TF groups were comparable for: 30-day mortality (Odds ratio, OR 0.75, 95% CI 0.49 – 1.16, p = 0.195); in-hospital stroke (OR 1.05, 95% CI 0.60–1.85, p = 0.859); myocardial infarction (OR 1.97, 95% CI 0.74–5.23, p = 0.176); paravalvular leaks (OR 1.20, 95% CI 0.76–1.90, p = 0.439); rates of postoperative permanent pacemaker implantation (OR 1.49, 95% CI 0.92–2.41, p = 0.105); in-hospital bleeding and meta-analysis demonstrated no significant difference between access points (OR 3.44, 95% CI 0.35–34.22, p = 0.292). Procedural time was found to be longer in the TSc group (SMD 1.02; 95% CI 0.815–1.219, p < 0.001). Major vascular complications were significantly higher in the TF group (OR 0.55, 95% CI 0.32–0.94, p = 0.029). Meta regression found no influence of the covariates on the outcomes. Conclusion Subclavian access is both a safe and feasible alternative access route for TAVI with lower risks of major vascular complications. This study supports the use of subclavian access as a viable alternative in patient groups where transfemoral TAVI is contraindicated

Novel technique for constraining r-process (n,γ\gamma) reaction rates

A novel technique has been developed, which will open exciting new opportunities for studying the very neutron-rich nuclei involved in the r-process. As a proof-of-principle, the $\gamma$-spectra from the $\beta$-decay of $^{76}$Ga have been measured with the SuN detector at the National Superconducting Cyclotron Laboratory. The nuclear level density and $\gamma$-ray strength function are extracted and used as input to Hauser-Feshbach calculations. The present technique is shown to strongly constrain the $^{75}$Ge($n,\gamma$)$^{76}$Ge cross section and reaction rate.Comment: 5 pages, 3 figure