59 research outputs found

    PICTORIAL REVIEW OF EXTRAOSSEOUS EWING’S TUMOUR: A SINGLE CENTER EXPERIENCE

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    Purpose: Ewing’s family tumour is an extremely rare tumour, with annual incidence rates amongst Caucasian children <21 years being in the range of 2–3 cases per million in the U.S. There are mainly three subtypes including Ewing’s sarcoma (ES) of bone, extraosseous (EO) Ewing’s tumour and Peripheral primitive neuroectodermal tumour. Although extremely rare, this study represents a review of various types of cases and the significance of imaging including its baseline and post-treatment response radiological characteristics. There are a very few cases of EO ES in the current literature with variable spectrum of tumour site and their imaging characteristics.Materials and Methods: Electronic records were retrospectively reviewed from 1 May 2011 to 1 May 2016 with patients who were diagnosed as histologically proven ES. A number of patients, gender and base line computed tomography (CT)/magnetic resonance imaging findings for staging were reviewed.Results: A total of 568 patients with diagnosed ES were analysed, of which 15 patients had EO type of ES. Of these only 8 patients had baseline imaging available which included tumours arising from the occipital region, orbit, anterior mediastinum, anterior abdominal wall, mesentery, kidney, prostate gland and presacral region.Conclusion: EO ES is a rare entity and can involve a wide array of soft tissue organs. A cross-sectional imaging with CT and MR has a key role in pre- and post-treatment assessment.Key words: Computed tomography, Ewing’s sarcoma, extraosseous Ewing’s, magnetic resonance imaging, peripheral primitive neuroectodermal tumou

    Active Distribution Networks Planning Considering Multi-DG Configurations and Contingency Analysis

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    YesThis paper proposes a novel method for planning active distribution networks (ADNs) with the integration of an active network management (ANM) scheme using coordinated voltage control (CVC) through on-load tap changer (OLTC) transformers. The method was formulated as a security-constrained optimal power flow (SCOPF) problem to minimize total operational costs, which maximizes the utilization of renewable distributed generators (DGs) over a planning horizon. The ANM scheme was applied using OLTC to ensure safe operation and reduce voltage violations in the network. To analyse the impact of ANM, the planning problem was examined both with and without the ANM scheme. Moreover, SCOPF, considering the N-1 line contingency analysis and multi-DG configuration, was implemented to analyse the feasibility of the proposed method and the advantages of ANM under contingency situations. The method was validated on a weakly-meshed 16-bus UK generic distribution system (UKGDS). The results showed that ANM can lower operational costs and maintain network voltage for operation in feasible conditions even in the case of a contingency. Moreover, the ANM scheme mitigated the voltage rise effect caused by DGs and maximized their utilization

    Effect of Heat Sink Configuration on the COP of Thermoelectric Vaccine Refrigerator

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    Polio vaccines are significantly sensitive to temperature and environment. During polio vaccination campaigns in far off villages of Pakistan, it is one of the biggest challenges to store and transport the vaccine without affecting its quality. Various refrigeration techniques are used to keep the vaccine below ambient temperature. The energy consumption of conventional refrigeration systems is too high and the refrigerants having CFCs are hazardous to environment, contributing to global warming by depleting ozone layer. These are also slightly difficult to be developed into a lightweight and portable solar devices used outside.  Solar Powered Thermoelectric Refrigerator (SPTR) is a distinct type of refrigeration system which runs on solar energy rather than that of conventional source of electrical energy, based upon the peltier effect to create hot and cold sides. The current research work was carried out at the Mechanical Engineering Department, U.E.T. Lahore (KSK Campus). The experimental results indicated the unit is capable to maintain a temperature of 6 0C at an ambient temperature below that of 50 0C. The maximum coefficient of performance was recorded as 0.78. Special configuration of heat sink was used to get maximum heat dissipation with minimum cost. An optimal value of solar irradiance let the cooling rate and coefficient of performance to attain maximum value. The designed SPTR would be of a great potential for cold storage in the areas where electricity supply is absent. It has the advantages of being small, lightweight, low running cost, noiseless, portable, reliable, and also low initial cost in mass production. &nbsp

    In situ immobilization of CuO on SiO\u3csub\u3e2\u3c/sub\u3e/graphite matrix, modified with benzimidazolium-1-acatate ionic liquid: Application as catechol sensor

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    © 2017 Carbon ceramic material (SiO2/C) was prepared using the sol-gel technique. Copper oxide was in situ synthesized on the pores of the matrix, to ensure homogenous distribution of the electroactive species in the matrix pores. To enhance the conductivity of material, the SiO2/C/CuO was modified with benzimidazolium-1-acetate ionic liquid. The surface area (SBET 432.56 m2/g) and pore volume (0.90 cm3/g) of the material were calculated from BET analysis. SEM images showed compactness of materials, having no phase segregation within the magnification used. The structure of ionic liquid was confirmed using NMR and FTIR analysis. The electrodes as a pressed disk fabricated from SiO2/C, SiO2/C/CuO, and SiO2/C/CuO/IL materials were tested as an electrochemical sensor for catechol determination. Electrochemical impedance spectroscopy has revealed that the SiO2/C/CuO/IL-based sensor assists the charge transfer owing to electron rich density, resonance, and conductance of ionic liquid structural moiety. SiO2/C/CuO/IL electrode exhibits excellent sensitivity, linear response range and low limit of detection (LOD) of 712 ÎŒA ÎŒmol− 1 dm3 cm− 2, 0.2 mM–10 mM and 0.7 × 10− 8 mol L− 1, respectively. The sensor was also tested for the determination of catechol in real samples and gives very good results for its determination

    Synthesis of 5-Fluorouracil Cocrystals with Novel Organic Acids as Coformers and Anticancer Evaluation against HCT-116 Colorectal Cell Lines

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    5-Fluorouracil (5-FU) being a mainstream anticancer drug is under keen and detailed investigation for prodrugs formulations in order to minimize the associated side effects. Cocrystallization of 5-FU is an innovative technique for the synthesis of 5-FU prodrugs to improve its anticancer effectiveness. The present study is based on the synthesis of 5-FU supramolecular synthons with four coformers: succinic acid, cinnamic acid, malic acid, and benzoic acid utilizing acetone as a solvent. Solid state grinding followed by a slow evaporation solution method was applied. Colorless clear crystals were obtained in all the cases. The cocrystal formation was supported with the help of Fourier transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD). Through FTIR, the main peaks of interest in the spectrum of 5-FU were N–H (3409.02 cm–1) and carbonyl group (1647.80 cm–1), which were prominently shifted in all spectra of the cocrystals demonstrating the replacement as well as the development of already present interactions with the new ones. For 5-FU–cinnamic acid cocrystals, the anticipated peaks were observed at 1673.13 cm–1 (−C═O) and 3566.89 cm–1 (N–H) manifesting a significant change in comparison to 5-FU. Furthermore, with the help of PXRD characterization, the representative peak of 5-FU was recorded at 2Ξ = 28.80°. The shifting of this specific peak and development of many new ones in the spectra of cocrystals proved the development of new structural entities. Finally, the anticancer activity of all cocrystals was evaluated in comparison to that of API. All cocrystals manifest significantly greater growth inhibition potential than the main active pharmaceutical ingredient. 5-FU–Cinnamic acid (3C) was the one that proved to be the most potent anticancer agent at all four concentrations: 4.82% (12 ÎŒg/mL), 34.21% (25 ÎŒg/mL), 55.08% (50 ÎŒg/mL), and 67.29% (100 ÎŒg/mL). In short, this study proved to be a true example to enhance the anticancer potential of 5-FU following fairly easy fabrication requirements of the cocrystallization phenomenon. After the successful synthesis of these supramolecular synthons and subsequent enhancement of growth inhibition potential of 5-FU, these cocrystals can further be evaluated for in vivo trials and membrane crossing potentials in the future

    A New Robust Control Strategy for Parallel Operated Inverters in Green Energy Applications

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    This research work puts forward a hybrid AC/DC microgrid with renewable energy sources pertaining to consumer’s residential area for meeting the demand. Currently, the power generation and consumption have experienced key transformations. One such tendency would be integration of microgrids into the distribution network that is characterized by high penetration of renewable energy resources as well as operations in parallel. Traditional droop control can be employed in order to get an accurate steady state averaged active power sharing amongst parallel inverters pertaining to hybrid AC/DC microgrid. It is presumed that there would be similar transient average power responses, and there would be no circulating current flowing between the units for identical inverters possessing the same droop gain. However, the instantaneous power could be affected by different line impedances considerably and thus resulting in variation in circulating power that flows amongst inverters, especially during unexpected disturbances like load changes. This power, if absorbed by the inverter, could result in sudden DC-link voltage rise and trip the inverter, which in turn causes performance degradation of the entire hybrid microgrid. When the hybrid generators act as unidirectional power source, the issue worsens further. In this research work, we have put forward a new distributed coordinated control pertaining to hybrid microgrid, which can be applied for both grid connected and islanded modes that include variable loads and hybrid energy resources. Also, in order to choose the most effective controller scheme, a participation factor analysis has been designed for binding the DC-link voltage as well as reducing the circulating power. Moreover, to both photovoltaic stations and wind turbines, maximum power point tracking (MPPT) techniques have been used in order to extract the maximum power from hybrid power system when there is discrepancy in environmental circumstances. Lastly, the feasibility and effectiveness pertaining to the introduced strategy for hybrid microgrid in various modes are confirmed via simulation results

    Socially-aware congestion control in ad-hoc networks: Current status and the way forward

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    Ad-hoc social networks (ASNETs) represent a special type of traditional ad-hoc network in whicha user’s social properties (such as the social connections and communications metadata as wellas application data) are leveraged for offering enhanced services in a distributed infrastructurelessenvironments. However, the wireless medium, due to limited bandwidth, can easily suffer from theproblem of congestion when social metadata and application data are exchanged among nodes—a problem that is compounded by the fact that some nodes may act selfishly and not share itsresources. While a number of congestion control schemes have been proposed for the traditional ad-hoc networks, there has been limited focus on incorporating social awareness into congestion controlschemes. We revisit the existing traditional ad-hoc congestion control and data distribution protocolsand motivate the need for embedding social awareness into these protocols to improve performance.We report that although some work is available in opportunistic network that uses socially-awaretechniques to control the congestion issue, this area is largely unexplored and warrants more researchattention. In this regards, we highlight the current research progress and identify multiple futuredirections of research

    Mulberry based zinc nano-particles mitigate salinity induced toxic effects and improve the grain yield and zinc bio-fortification of wheat by improving antioxidant activities, photosynthetic performance, and accumulation of osmolytes and hormones

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    Salinity stress (SS) is a challenging abiotic stress that limits crop growth and productivity. Sustainable and cost effective methods are needed to improve crop production and decrease the deleterious impacts of SS. Zinc (Zn) nanoparticles (NPs) have emerged as an important approach to regulating plant tolerance against SS. However, the mechanisms of SS tolerance mediated by Zn-NPs are not fully explained. Thus, this study was performed to explore the role of Zn-NPs (seed priming and foliar spray) in reducing the deleterious impacts of SS on wheat plants. The study comprised different SS levels: control, 6 and 12 dS m−1, and different Zn-NPs treatments: control, seed priming (40 ppm), foliar spray (20 ppm), and their combination. Salinity stress markedly reduced plant growth, biomass, and grain yield. This was associated with enhanced electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H2O2), sodium (Na), chloride (Cl) accumulation, reduced photosynthetic pigments, relative water contents (RWC), photosyntetic rate (Pn), transpiration rate (Tr), stomata conductance (Gs), water use efficiency (WUE), free amino acids (FAA), total soluble protein (TSP), indole acetic acid (IAA), gibberellic acid (GA), and nutrients (Ca, Mg, K, N, and P). However, the application of Zn-NPs significantly improved the yield of the wheat crop, which was associated with reduced abscisic acid (ABA), MDA, H2O2 concentration, and EL, owing to improved antioxidant activities, and an increase in RWC, Pn, Tr, WUE, and the accumulation of osmoregulating compounds (proline, soluble sugars, TSP, and FAA) and hormones (GA and IAA). Furthermore, Zn-NPs contrasted the salinity-induced uptake of toxic ions (Na and Cl) and increased the uptake of Ca, K, Mg, N, and P. Additionally, Zn-NPs application substantially increased the wheat grain Zn bio-fortification. Our results support previous findings on the role of Zn-NPs in wheat growth, yield, and grain Zn bio-fortification, demonstrating that beneficial effects are obtained under normal as well as adverse conditions, thanks to improved physiological activity and the accumulation of useful compounds. This sets the premise for general use of Zn-NPs in wheat, to which aim more experimental evidence is intensively being sought. Further studies are needed at the genomic, transcriptomic, proteomic, and metabolomic level to better acknowledge the mechanisms of general physiological enhancement observed with Zn-NPs application
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