441 research outputs found

    Energy consumption and capacity utilization of galvanizing furnaces

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    An explicit equation leading to a method for improving furnace efficiency is presented. This equation is dimensionless and can be applied to furnaces of any size and fuel type for the purposes of comparison. The implications for current furnace design are discussed. Currently the technique most commonly used to reduce energy consumption in galvanizing furnaces is to increase burner turndown. This is shown by the analysis presented here actually to worsen the thermal efficiency of the furnace, particularly at low levels of capacity utilization. Galvanizing furnaces are different to many furnaces used within industry, as a quantity of material (in this case zinc) is kept molten within the furnace at all times, even outside production periods. The dimensionless analysis can, however, be applied to furnaces with the same operational function as a galvanizing furnace, such as some furnaces utilized within the glass industry. © IMechE 2004

    Surface-enhanced Raman encoded polymer stabilized gold nanoparticles : demonstration of potential for use in bioassays

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    The preparation of biotinylated, self-assembled polymer stabilized gold nanoparticle hybrids encoded with a SERS active compound is described. The polymers used for nanoparticle stabilization are carefully designed for this purpose and are synthesized by the RAFT polymerization process, as the thiocarbonylthio end group provides a functional handle for anchoring the polymers to the gold surface. Functionalized biotin moieties are attached to the hybrid nanoparticles via Cu-catalyzed azide-alkyne cycloaddition. Binding of the biotinylated hybrid nanoparticles to streptavidin was confirmed by nanoparticle detection and identification by the SERS spectrum of the surface-bound SERS active compound, quinoline thiol. This investigation includes the requisites that constitute a bioassay, demonstrating the potential of polymer-coated hybrid nanoparticles for this purpose

    Cellular glutathione as a determinant of the sensitivity of colorectal tumour cell-lines to ZD2767 antibody-directed enzyme prodrug therapy (ADEPT)

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    ZD2767P, a nitrogen mustard glutamate prodrug, is currently being evaluated in Phase 1 clinical trials of antibody directed enzyme prodrug therapy (ADEPT). There was no significant relationship between basal glutathione (GSH) concentration and sensitivity to ZD2767P + carboxpeptidase G2 (CPG2) in colorectal tumour cell-lines. Depletion of intracellular GSH using buthionine sulfoximine (BSO) resulted in only a modest potentiation of ZD2767P + CPG2 activity and hence BSO is unlikely to markedly enhance the activity of this ADEPT treatment. © 2000 Cancer Research Campaig

    Antibiotic Choice and Duration Associate with Repeat Prescriptions in Infective Asthma Exacerbations

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    Background: Patients with asthma who present with lower respiratory tract infections (LRTIs) often receive antibiotics. There is uncertainty about the need for and consequences of antibiotic administration. Objective: To describe the demographic characteristics of and antibiotic prescriptions for adult patients with asthma with LRTI and investigate factors associated with repeat antibiotic courses. Methods: We analyzed prescriptions of antibiotics for LRTIs in UK primary care from 2010 to 2015 using the Optimum Care Database. The primary outcome was a second antibiotic prescription for an LRTI code within 14 days of index prescription, as a proxy of initial treatment failure. A model for repeat prescriptions was derived using univariable and multivariable logistic regression analyses. Results: We assessed 28,289 cases with complete data sets, 6.5% of which received a second antibiotic course. Amoxicillin and clarithromycin respectively were used most commonly as index and second agents. The most frequent course length was 7 days for both index and repeat prescriptions. Multivariable analysis demonstrated that age, index antibiotic and duration, smoking status, location, and number of consultations and oral steroid courses in the previous year were significantly associated with repeat prescriptions. The derived model predicted the binary outcome adequately (Cox-Snell R2, 0.012; area under curve, 0.62; 95% CI, 0.61-0.63). Comorbidities, vaccinations, asthma treatment, and number of exacerbations were significant only in the univariable analysis. Conclusions: The current index prescribing preference of 7 days of amoxicillin correlated to fewer repeat courses. Baseline asthma treatment was not associated with risk of further prescriptions. Antibiotic administration in older patients with a smoking history could be a target for future studies

    Amoxicillin is associated with a lower risk of further antibiotic prescriptions for lower respiratory tract infections in primary care - A database analysis spanning over 30 years.

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    Antibiotic prescriptions for lower respiratory tract infections occur commonly in primary care but there is uncertainty about the most effective initial treatment strategy. Both increasing antimicrobial resistance and awareness of preventable harm from medicines make resolving this uncertainty a priority. Pragmatic, real-life epidemiological investigations are needed to inform future interventional studies. In this cross-sectional database study we analysed antibiotic prescriptions for non-pneumonic, lower respiratory tract infections (LRTI) in primary care as captured in the Optimum Care Database from 1984 to 2017. The primary outcome was a second antibiotic prescription for a LRTI code within 14 days of index prescription, the secondary outcome further antibiotic prescription for any indication. Only individuals without chronic respiratory diseases were included. We conducted univariable analysis to identify factors associated with repeat prescriptions and generate hypotheses for forthcoming projects. We analysed 367,188 index prescriptions for LRTI. Amoxicillin was the commonest used index drug (65.1%). In 6% a second antibiotic course coded for a further LRTI was prescribed (11.2% without this coding restriction). Further antibiotic prescriptions for LRTI were significantly associated with older age, previous smoking, seven day index courses and not using amoxicillin initially. The largest effect size was seen when amoxicillin was not used as index drug (odds ratio (OR) 1.15, p < 0.001). This would support current prescribing practice for amoxicillin as index drug in those without respiratory disease. Prospective studies are needed to explore the observed differences

    The Role of Executive Functions in Socioeconomic Attainment Gaps: Results From a Randomized Controlled Trial

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    The socioeconomic attainment gap in mathematics starts early and increases over time. This study aimed to examine why this gap exists. Four‐year‐olds from diverse backgrounds were randomly allocated to a brief intervention designed to improve executive functions (N = 87) or to an active control group (N = 88). The study was preregistered and followed CONSORT guidelines. Executive functions and mathematical skills were measured at baseline, 1 week, 3 months, 6 months, and 1 year posttraining. Executive functions mediated the relation between socioeconomic status and mathematical skills. Children improved over training, but this did not transfer to untrained executive functions or mathematics. Executive functions may explain socioeconomic attainment gaps, but cognitive training directly targeting executive functions is not an effective way to narrow this gap

    The Role of Executive Functions in Socioeconomic Attainment Gaps: Results From a Randomized Controlled Trial

    Get PDF
    The socioeconomic attainment gap in mathematics starts early and increases over time. This study aimed to examine why this gap exists. Four‐year‐olds from diverse backgrounds were randomly allocated to a brief intervention designed to improve executive functions (N = 87) or to an active control group (N = 88). The study was preregistered and followed CONSORT guidelines. Executive functions and mathematical skills were measured at baseline, 1 week, 3 months, 6 months, and 1 year posttraining. Executive functions mediated the relation between socioeconomic status and mathematical skills. Children improved over training, but this did not transfer to untrained executive functions or mathematics. Executive functions may explain socioeconomic attainment gaps, but cognitive training directly targeting executive functions is not an effective way to narrow this gap

    Detection and metabolic investigations of a novel designer steroid: 3-chloro-17α-methyl-5α-androstan-17β-ol

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    In 2012, seized capsules containing white powder were analyzed to show the presence of unknown steroid-related compounds. Subsequent gas chromatography–mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) investigations identified a mixture of 3α- and 3β- isomers of the novel compound; 3-chloro-17α-methyl-α-androstan-17β-ol. Synthesis of authentic reference materials followed by comparison of NMR, GC-MS and gas chromatography-tandem mass spectrometry (GC-MS/MS) data confirmed the finding of a new ‘designer’ steroid. Furthermore, in vitro androgen bioassays showed potent activity highlighting the potential for doping using this steroid. Due to the potential toxicity of the halogenated steroid, in vitro metabolic investigations of 3α-chloro-17α-methyl-α-androstan-17β-ol using equine and human S9 liver fractions were performed. For equine, GC-MS/MS analysis identified the diagnostic 3α-chloro-17α-methyl-5α-androstane-16α,17β-diol metabolite. For human, the 17α-methyl-α-androstane-3α,17β-diol metabolite was found. Results from these studies were used to verify the ability of GC-MS/MS precursor-ion scanning techniques to support untargeted detection strategies for designer steroids in anti-doping analyses.Synthesis and in vitro metabolic investigations of 3α/β-chloro-17α-methyl-5α-androstan -17β-ol was suppo rted by the Austr a-lian Research Council Linkage Grant (LP120200444) Strat egies for the detection of designer ster oids in ra cehorses
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