174 research outputs found

    Dose Determination of Activated Charcoal in Management of Amitriptyline-Induced Poisoning by Reversed-Phase High-Performance Liquid Chromatography

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    Purpose: To assess the doses of activated charcoal currently used in the management of acute amitriptyline-induced drug poisoning and explore the possibility of using lower doses.Methods: Albino male Wistar rats, weighing 200 ± 20 g, were used for the study. The animals were divided into four groups of eight animals each. The concentration of amitriptyline in rat plasma was measured by high performance liquid chromatography (HPLC) for dose determination of activated charcoal. Chromatograms were established with acetonitrile: 70 mM KH2PO4 buffer (60: 40, v/v) solvent system on an Xterna® ms C18 SUM column (5 μm, 3.9 × 150 mm) and pH was adjusted to 4.5 with ortho-phosphoric acid. Mobile phase flow rate was 1 ml/min and ultraviolet (UV) detection was at 293 nm. Validation of the method was performed to determine its selectivity, linearity, precision, as well as limits of detection (LOD) and of quantification (LOQ).Results: Standard curves were linear, r2 = 0.996, for amitriptyline over the concentration range 10 - 60 ng/ml. Recovery (98.3 to 100.85 %) was in the selected concentration range of 10 - 60 ng/ml. The LOD and LOQ of the method for amitriptyline were 0.109 and 0.332 μg/ml, respectively. The validated method was successfully applied to measure plasma concentrations of amitriptyline and to measure the doses of activated charcoal currently used in the management of acute amitriptyline drug poisoning.Conclusion: The proposed RP-HPLC method enables determination of amitriptyline with good separation and resolution of the chromatographic peaks. Validation revealed that the method is sensitive, accurate and selective. Using half of the standard dose of the activated charcoal gave a comparable effect to the standard dose in reducing drug concentration in the blood. While, using quarter of the standard dose of activated charcoal does not have a cleared effect.Keywords: Amitriptyline, Activated charcoal, Drug poisoning, Reversed-phase high-performance liquid chromatograph

    A New Four-Quadrant Inverter Based on Dual-Winding Isolated Cuk Converters for Railway and Renewable Energy Applications

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    The paper presents a new four-quadrant converter based on dual-winding isolated Cuk converters. The proposed converter can operate as a DC/DC converter, DC/AC inverter or AC/DC rectifier. The new converter offers important merits such as losses reduction, voltage boosting, flexible output voltage range, passive element reduction and galvanic isolation with small-size high-frequency transformers. If the proposed converter output is applied to a DC motor, providing the possibility of motoring, braking and regenerative braking if required. In addition, the converter offers the possibility to generate AC voltages and currents if it is employed in renewable energy systems as a DC/AC inverter. The paper presents the description of the converter with the associated mathematical analysis. Simulation results are obtained using MATLAB/SIMULINK software while experimental results are obtained using a scaled down prototype, controlled by TMS320F28335DSP

    A New Modular Three-phase Inverter Based on Sepic-Cuk Combination Converter for Photovoltaic Applications

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    A new modular dc/ac inverter based on a dual-winding isolated SEPIC/Cuk converter for medium and high power Photovoltaic (PV) applications is introduced. In this system, several current-source submodules (SMs) are connected in series to allow for additional voltage boosting. Each SM is designed as a combination of SEPIC/CUK converter to offer a flexible output range and continuous currents with small ripple at input and output sides. Furthermore, the SMs structure can generate different output voltage polarities. The main purpose of employing small-size highfrequency transformers are to (1) provide galvanic isolation, (2) eliminate PV grounding problems, (3) achieve minimum electromagnetic interference (EMI). The paper presents a description of the proposed topology and investigate its reliability performance in a PV grid-tied system using MATLAB simulations. An experimental prototype has been used and controlled by TMS32028335 DSP, as a proof of concept

    The Influence Of Point Defects And Dislocation On AlGaN-Based Deep Ultraviolet LEDs

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    AlGaN-based deep ultraviolet LEDs with high Al composition are promising for many applications, including air- or water-purification, fluorescence sensing, etc. However, to realize their full potential, it is important to understand the impact of the point defects on the device performance. Here, we investigate the defects in the 265 nm AlGaN-based deep ultraviolet LEDs after degradation systematically with a combination of different analytical technologies. The results show that point defects increase after the degradation. The generated defects during the stress lead to a carrier redistribution in the active region and the induced point defects during the degradation are located within the multi-quantum wells (MQWs) region, especially in the first quantum well near the p side of the LED chip. The dislocation lines in the MQWs region were also observed after the degradation, which can lead to the Mg diffusion along the dislocation line. These findings are important to understand the defects in AlGaN quantum wells and further improve AlGaN-based deep ultraviolet LEDs’ performance

    Tuberculosis Trends in Saudis and Non-Saudis in the Kingdom of Saudi Arabia – A 10 Year Retrospective Study (2000–2009)

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    Tuberculosis (TB) remains a public health problem in the Kingdom of Saudi Arabia (KSA), which has a very large labour force from high TB endemic countries. Understanding the epidemiological and clinical features of the TB problem, and the TB burden in the immigrant workforce, is necessary for improved planning and implementation of TB services and prevention measures

    The Saudi experiment with career guidance

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    Saudi Arabia has recently embarked on an ambitious experiment with career guidance. The country has identified that career guidance offers a range of potential cultural, educational and economic benefits. These include supporting the Saudisation of the workforce, the development of the vocational education system and the engagement of the Saudi ‘youth bulge’ in the labour market and wider society. However, the country has a weak tradition of career guidance and a need to develop new policies and systems rapidly. The Saudi Ministry of Labour has driven the development of the country’s new career guidance system and has sought to learn from global best practice. However, Saudi Arabia offers a very different context from those where career guidance has flourished. Particularly distinctive features of Saudi society include its limited civil society, the central role that religion plays, the place of women, the role of oil within the economy and the high level of migrant workers in the labour market. Taken together these issues offer challenges of culture, theory, policy and practice. Negotiating these challenges and building an organic body of theory and practice will be critical to the success or otherwise of the Saudi experiment with career guidance.N/

    A computational model of excitation and contraction in uterine myocytes from the pregnant rat

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    Aberrant uterine myometrial activities in humans are major health issues. However, the cellular and tissue mechanism(s) that maintain the uterine myometrium at rest during gestation, and that initiate and maintain long-lasting uterine contractions during delivery are incompletely understood. In this study we construct a computational model for describing the electrical activity (simple and complex action potentials), intracellular calcium dynamics and mechanical contractions of isolated uterine myocytes from the pregnant rat. The model reproduces variant types of action potentials – from spikes with a smooth plateau, to spikes with an oscillatory plateau, to bursts of spikes – that are seen during late gestation under different physiological conditions. The effects of the hormones oestradiol (via reductions in calcium and potassium selective channel conductance), oxytocin (via an increase in intracellular calcium release) and the tocolytic nifedipine (via a block of L-type calcium channels currents) on action potentials and contractions are also reproduced, which quantitatively match to experimental data. All of these results validated the cell model development. In conclusion, the developed model provides a computational platform for further investigations of the ionic mechanism underlying the genesis and control of electrical and mechanical activities in the rat uterine myocytes

    SPARC 2018 Internationalisation and collaboration : Salford postgraduate annual research conference book of abstracts

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    Welcome to the Book of Abstracts for the 2018 SPARC conference. This year we not only celebrate the work of our PGRs but also the launch of our Doctoral School, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 100 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
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