377 research outputs found

    Value of “large FOV” calcium score as a screening method for detection of extracardiac incidental findings

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    AbstractPurposeThe purpose of this study was to emphasize the value of calcium scoring (Ca score) using a large field of view (“large FOV”) as a screening method for detection of extracardiac incidental findings.Materials and methods64-Multislice CT angiography using a “large FOV” in the preliminary calcium score followed by the post-contrast routine “small FOV” examination was performed for 382 consecutive patients between January 2011 and December 2012.Results375 Patients (203 men and 172 women) with age range between 40 and 80years (mean, 60years), were studied, using a “large FOV” technique. Among whole incidental extracardiac findings, “significant” extracardiac abnormalities (emergent and intermediate findings) were detected in 24.8% of cases, among which 13.6% would have been missed if only using a “small FOV” technique.ConclusionResults showed that using Ca score with a “large FOV” is favorable for better, accurate and more frequent detection of extracardiac incidental findings. With usage of low dose technique, the difference in dose between “small FOV” and “large FOV” techniques is justified for detection of supplementary “significant” extra-cardiac findings including serious findings such as lung cancer or metastatic deposits

    A NEW METHOD FOR SOLVING LINEAR PROGRAMMING PROBLEMS

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    ABSTRACT Anew method which does not depend on the simplex method for solving the linear programming (LP) problems is given. The proposed method is based mainly upon solving this problem algebraically using the concept of duality .The important of this method is that we are not based our work on vertex information which may have difficulties as the problem size increases. A simple example is given to clarify the developed theory of this proposed method

    A novel method for the analysis of particle coating behaviour via contact spreading in a tumbling drum: Effect of coating liquid viscosity

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    Spray coating is a common method of distributing liquids over powders, especially in the pharmaceutical, detergent and food industries. During this process, liquid drops are deposited on the surface of particles. Liquid is then transferred between particles via particle collisions, in a process called liquid contact spreading. This contact spreading process facilitates inter-particle coating, in which wetting, de-wetting, mixing and drying are occurring simultaneously. This work presents the first experimental study of the mechanism of liquid contact spreading. In this work, a novel experimental method has been developed to investigate the mechanism of contact spreading, incorporating a newly developed image analysis technique, based on colourimetric measurements, to quantitatively determine coating behaviour via contact spreading. Here, experiments designed to isolate the contact spreading coating mechanism were performed in a tumbling drum using a model material system; alumina particles and dyed polyethylene glycol solutions of varying viscosities. The coating uniformity was quantified by the variation in inter-particle coating; the coefficient of variation (CoV). For all systems, the uniformity of the coating increased with time until the CoV decreased to an asymptotic value. The rate of the decrease in the CoV was successfully fitted using an exponential decay function. The viscosity of the coating solution had a significant effect on the rate of liquid transfer; the lower the viscosity the faster the contact spreading process. This effect is attributed to differences in the formation and stability of liquid bridges between the particles, influencing the extent of liquid transfer. The results also show that in most cases examined here, viscous forces play a main role in the contact spreading process, and the contribution of capillary forces are minimal. This understanding could assist the design and scale up for the wet coating processes

    Anti-hepatotoxic effect of Casuarina stricta and Casuarina suberosa extracts on alcohol-induced liver toxicity in rats

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    In recent years, there has been a global trend toward the use of natural phytochemicals present in natural resources, such as fruits, vegetables, oilseeds, and herbs, as antioxidants and functional foods. The aim of the present study was to investigate the protective and antioxidant effects of methanolic extract of Casuarina stricta and Casuarina suberosa leaves on ethanol induced hepatotoxicity in rats. The ethanol intoxication (1 ml of 40 % ethanol for 100 gm body weight for 6 weeks) to rats resulted in a significant increase in serum ALT, AST, \u3b3 glutamyl transferase (\u3b3 GT), hydroxyproline, MDA level and a significant decrease in serum albumin, total protein, A/G ratio, total antioxidant capacity, SOD, catalase activities and GSH level, P < 0.05. The treatment with Casuarina stricta and Casuarina suberosa extract at a dose of 250 mg/Kg body weight together with ethanol for 6 weeks successfully prevented the alterations of studied parameters in the treated groups. Both extracts significantly increased the total antioxidant capacity. The experimental results indicate that, both Casuarina extracts have excellent hepatoprotective effect

    Tuning electro-magnetic interference shielding efficiency of customized polyurethane composite foams taking advantage of rGO/Fe3O4 hybrid nanocomposites

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    Electromagnetic interference (EMI) has been recognized as a new sort of pollution and can be considered as the direct interference of electromagnetic waves among electronic equipment that frequently affects their typical efficiency. As a result, shielding the electronics from this interfering radiation has been addressed as critical issue of great interest. In this study, different hybrid nanocomposites consisting of magnetite nanoparticles (Fe3O4) and reduced graphene oxide (rGO) as (conductive/magnetic) fillers, taking into account different rGO mass ratios, were synthesized and characterized by XRD, Raman spectroscopy, TEM and their magnetic properties were assessed via VSM. The acquired fillers were encapsulated in the polyurethane foam matrix with different loading percentages (wt%) to evaluate their role in EMI shielding. Moreover, their structure, morphology, and thermal stability were investigated by SEM, FTIR, and TGA, respectively. In addition, the impact of filler loading on their final mechanical properties was determined. The obtained results revealed that the Fe3O4@rGO composites displayed superparamagnetic behavior and acceptable electrical conductivity value. The performance assessment of the conducting Fe3O4@rGO/PU composite foams in EMI shielding efficiency (SE) was investigated at the X-band (8–12) GHz, and interestingly, an optimized value of SE −33 dBw was achieved with Fe3O4@rGO at a 80:20 wt% ratio and 35 wt% filler loading in the final effective PU matrix. Thus, this study sheds light on a novel optimization strategy for electromagnetic shielding, taking into account conducting new materials with variable filler loading, composition ratio, and mechanical properties in such a way as to open the door for achieving a remarkable SE.Ministerio de Ciencia e Innovación | Ref. PID2020-113704RB-I00Xunta de Galicia | Ref. ED431G 2019/06Xunta de Galicia | Ref. IN607A 2018/5Xunta de Galicia | Ref. ED431C 2021/45Unión Europea-FEDER (Interreg V-A—España-Portugal) | Ref. 0245_IBEROS_1_EUnión Europea-FEDER (Interreg V-A—España-Portugal) | Ref. 0712_ACUINANO_1_EUnión Europea-FEDER (Interreg V-A—España-Portugal) | Ref. 0624_2IQBIONEURO_6_

    Transfer hydrogenation as a redox process in nucleotides

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    © 2014 American Chemical Society. Using a combined theoretical and experimental strategy, the heats of hydrogenation of the nucleotide bases uracil, thymine, cytosine, adenine, and guanine have been determined. The most easily hydrogenated base is uracil, followed by thymine and cytosine. Comparison of these hydrogenation enthalpies with those of ketones and aldehydes derived from sugar models indicates the possibility of near-thermoneutral hydrogen transfer between uracil and the sugar phosphate backbone in oligonucleotides. (Figure Presented

    Microfluidic SAXS study of lamellar and multilamellar vesicle phases of linear sodium alkylbenzenesulfonate surfactant with intrinsic isomeric distribution

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    The structure and flow behaviour of a concentrated aqueous solution (45 w.t. %) of the ubiquitous linear sodium alkylbenzene sulfonate (NaLAS) surfactant is investigated by microfluidic small-angle X-ray scatterong (SAXS) at 70 ⁰C. NaLAS is an intrinsically complex mixture of over 20 surfactant molecules, presenting coexisting micellar (L1) and lamellar (Lα) phases. Novel microfluidic devices were fabricated to ensure pressure and thermal resistance, ability to handle viscous fluids, and low SAXS background. Polarized light optical microscopy showed that the NaLAS solution exhibits wall slip in microchannels, with velocity profiles approaching plug flow. Microfluidic SAXS demonstrated the structural spatial heterogeneity of the system with a characteristic lengthscale of 50 nL. Using a statistical flow-SAXS analysis we identified the micellar phase and multiple coexisting lamellar phases with a continuous distribution of d spacings between 37.5 Å - 39.5 Å. Additionally, we showed that the orientation of NaLAS lamellar phases is strongly affected by a single microfluidic constriction. The bilayers align parallel to the velocity field upon entering a constriction and perpendicular to it upon exiting. On the other hand, multi-lamellar vesicle phases are not affected under the same flow conditions. Our results demonstrate that, despite the compositional complexity inherent to NaLAS, microfluidic SAXS can rigorously elucidate its structure and flow response
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