579 research outputs found

    Optimisation of Accelerated Solvent Extraction of Antioxidant Compounds from Rosemary (Rosmarinus officinalis L.), Marjoram (Origanum majorana L.) and Oregano (Origanum vulgare L.) Using Response Surface Methodology

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    The present study optimised the accelerated solvent extraction (ASE) conditions (Dionex ASE® 200, USA) to maximise the antioxidant capacity of the extracts from three spices of Lamiaceae family; rosemary, oregano and marjoram. Optimised conditions with regard to extraction temperature (66–129 °C) and solvent concentration (32–88% methanol) were identified using response surface methodology (RSM). For all three spices results showed that 129 °C was the optimum temperature in order to obtain extracts with high antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of rosemary and marjoram extracts were 56% and 57% respectively. Oregano showed a different response to the effect of methanol concentration and was optimally extracted at 33%. The antioxidant activity yields of the optimal ASE extracts were significantly (p \u3c 0.05) higher than solid/liquid extracts. The predicted models were highly significant (p \u3c 0.05) for both total phenol (TP) and ferric reducing antioxidant property (FRAP) values in all the spices with high regression coefficients (R2) ranging from 0.952 to 0.999

    Antioxidant Activity of Spice Extracts and Phenolics in Comparison to Synthetic Antioxidants

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    The antioxidant capacity of 30 spices used frequently in ready meals and a selection of key compounds from spices were investigated in the current study using ferric reducing antioxidant properties (FRAP), 2,2\u27-azinobis(3-ethylebenzothiaziline-6-sulfonate) (ABTS) and microsomal lipid peroxidation (MLP) assays. Antioxidant capacities of the spice extracts were compared to 5 popular synthetic antioxidants [buylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butylated hydroquinone (TBHQ), propyl gallate (PG) and octyl gallate (OG)]. Results showed that clove extracts had the highest antioxidant capacity as measured by FRAP, ABTS and MLP assays. Extracts from garlic powder were the lowest ranked of all the spices examined. Synthetic antioxidants were ranked in the following decreasing order of antioxidant activity PG \u3e BHA \u3e TBHQ \u3e OG \u3e BHT. Rosmarinic acid, a polyphenol commonly found in lamiaceae spices and eugenol from clove had higher antioxidant capacities than that of all synthetic antioxidants investigated. Antioxidant capacities of kaempferol from apiaceae spices, capsaicin from chilli, curcumin from turmeric, thymol from thyme and gingerol from ginger were also comparable to most of the synthetic antioxidants

    Exploring Front Line Ambulance Staff Perspectives of the Hospital Transfer Pathway

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    Guidance from the National Institute for Health and Care Excellence in the UK was introduced in 2015 to improve the quality of the care pathway of transfers of care home residents to hospital when needed. The Red Bag scheme was developed by Sutton Clinical Commissioning Group in 2016 as a means of improving communication between organisations involved in the process by ensuring residents’ notes and other personal belongings were easily identifiable and kept in one place. The Red Bag was implemented in the North East of England in 2018. The aim of this study was to understand the knowledge of and experiences of front line ambulance staff who had potential to be involved with the transfer of care home residents to hospital. A mixed methods approach was used for the study. Participants were recruited by two research paramedics working in the North East ambulance service and approached to take part in a confidential, on-line survey using Survey Monkey®. Data was analysed through descriptive statistics and a constant comparative analytic framework to develop into concepts found in the free text comments, which were constructed into themes. Two hundred and fifty eight participants were recruited to the study. Six themes were identified in the data that represented the knowledge and experiences of the participants. Findings showed there was variance in the implementation, interpretation and use of the Red Bag in practice. Where effective communication took place, handovers worked well, however perceived organisational processes and avoidable delays prevented the optimal transfer of care. Improved communication between organisations is recommended, along with building capacity and capability within and between professional disciplines working at the front line of patient care were identified as fundamental mechanisms of streamlining handover processes for the vulnerable and older adults who live in residential care settings

    Choice of method of place cell classification determines the population of cells identified

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    Place cells, spatially responsive hippocampal cells, provide the neural substrate supporting navigation and spatial memory. Historically most studies of these neurons have used electrophysiological recordings from implanted electrodes but optical methods, measuring intracellular calcium, are becoming increasingly common. Several methods have been proposed as a means to identify place cells based on their calcium activity but there is no common standard and it is unclear how reliable different approaches are. Here we tested four methods that have previously been applied to two-photon hippocampal imaging or electrophysiological data, using both model datasets and real imaging data. These methods use different parameters to identify place cells, including the peak activity in the place field, compared to other locations (the Peak method); the stability of cells’ activity over repeated traversals of an environment (Stability method); a combination of these parameters with the size of the place field (Combination method); and the spatial information held by the cells (Information method). The methods performed differently from each other on both model and real data. In real datasets, vastly different numbers of place cells were identified using the four methods, with little overlap between the populations identified as place cells. Therefore, choice of place cell detection method dramatically affects the number and properties of identified cells. Ultimately, we recommend the Peak method be used in future studies to identify place cell populations, as this method is robust to moderate variations in place field within a session, and makes no inherent assumptions about the spatial information in place fields, unless there is an explicit theoretical reason for detecting cells with more narrowly defined properties

    Pharmacokinetics and Safety of Prolonged Paracetamol Treatment in Neonates: An Interventional Cohort Study

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    Aims To investigate the pharmacokinetics and safety of prolonged paracetamol use (\u3e72 h) for neonatal pain. Methods Neonates were included if they received paracetamol orally or intravenously for pain treatment. A total of 126 samples were collected. Alanine aminotransferase and bilirubin were measured as surrogate liver safety markers. Paracetamol and metabolites were measured in plasma. Pharmacokinetic parameters for the parent compound were estimated with a nonlinear mixed-effects model. Results Forty-eight neonates were enrolled (38 received paracetamol for \u3e72 h). Median gestational age was 38 weeks (range 25–42), and bodyweight at inclusion was 2954 g (range 713–4750). Neonates received 16 doses (range 4–55) over 4.1 days (range 1–13.8). The median (range) dose was 10.1 mg/kg (2.9–20.3). The median oxidative metabolite concentration was 14.6 μmol/L (range 0.12–113.5) and measurable \u3e30 h after dose. There was no significant difference (P \u3e .05) between alanine aminotransferase and bilirubin measures at \u3c72 h or \u3e72 h of paracetamol treatment or the start and end of the study. Volume of distribution and paracetamol clearance for a 2.81-kg neonate were 2.99 L (% residual standard error = 8, 95% confidence interval 2.44–3.55) and 0.497 L/h (% residual standard error = 7, 95% confidence interval 0.425–0.570), respectively. Median steady-state concentration from the parent model was 50.3 μmol/L (range 30.6–92.5), and the half-life was 3.55 h (range 2.41–5.65). Conclusion Our study did not provide evidence of paracetamol-induced liver injury nor changes in metabolism in prolonged paracetamol administration in neonates

    Tracing PAHs and Warm Dust Emission in the Seyfert Galaxy NGC 1068

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    We present a study of the nearby Seyfert galaxy NGC 1068 using mid- and far- infrared data acquired with the IRAC, IRS, and MIPS instruments aboard the Spitzer Space Telescope. The images show extensive 8 um and 24 um emission coinciding with star formation in the inner spiral approximately 15" (1 kpc) from the nucleus, and a bright complex of star formation 47" (3 kpc) SW of the nucleus. The brightest 8 um PAH emission regions coincide remarkably well with knots observed in an Halpha image. Strong PAH features at 6.2, 7.7, 8.6, and 11.3 um are detected in IRS spectra measured at numerous locations inside, within, and outside the inner spiral. The IRAC colors and IRS spectra of these regions rule out dust heated by the AGN as the primary emission source; the SEDs are dominated by starlight and PAH emission. The equivalent widths and flux ratios of the PAH features in the inner spiral are generally consistent with conditions in a typical spiral galaxy ISM. Interior to the inner spiral, the influence of the AGN on the ISM is evident via PAH flux ratios indicative of a higher ionization parameter and a significantly smaller mean equivalent width than observed in the inner spiral. The brightest 8 and 24 um emission peaks in the disk of the galaxy, even at distances beyond the inner spiral, are located within the ionization cones traced by [O III]/Hbeta, and they are also remarkably well aligned with the axis of the radio jets. Although it is possible that radiation from the AGN may directly enhance PAH excitation or trigger the formation of OB stars that subsequently excite PAH emission at these locations in the inner spiral, the orientation of collimated radiation from the AGN and star formation knots in the inner spiral could be coincidental. (abridged)Comment: 20 pages, 11 figures; AJ, accepted; full resolution version available at http://spider.ipac.caltech.edu/staff/jhhowell/astro/howelln1068.pd

    Gridded and direct Epoch of Reionisation bispectrum estimates using the Murchison Widefield Array

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    We apply two methods to estimate the 21~cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly-spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uvuv-plane. The direct and gridded bispectrum estimators are applied to 21 hours of high-band (167--197~MHz; zz=6.2--7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 hours, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21~cm bispectrum may be accessible in less time than the 21~cm power spectrum for some wave modes, with detections in hundreds of hours.Comment: 19 pages, 10 figures, accepted for publication in PAS
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