2,656 research outputs found

    Synthesis and characterisation of Fe<sub>6</sub> and Fe<sub>12</sub> clusters using bicine

    Get PDF
    Reaction of bicine {BicH3, N,N-bis(2-hydroxyethyl)glycine} with an Fe(III) oxo-centered pivalate triangle in MeCN in the presence of Et&lt;sub&gt;2&lt;/sub&gt;NH yields [Et&lt;sub&gt;2&lt;/sub&gt;NH&lt;sub&gt;2&lt;/sub&gt;]&lt;sub&gt;2&lt;/sub&gt;[Fe&lt;sub&gt;6&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;(OH)&lt;sub&gt;2&lt;/sub&gt;(Bic)&lt;sub&gt;2&lt;/sub&gt;(O&lt;sub&gt;2&lt;/sub&gt;CCMe&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;8&lt;/sub&gt;], which possesses an S = 5 ground state. Changing the base to NaOMe produces [Fe&lt;sub&gt;12&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;(Bic)&lt;sub&gt;4&lt;/sub&gt;(HBic)&lt;sub&gt;4&lt;/sub&gt;(O&lt;sub&gt;2&lt;/sub&gt;CCMe&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;8&lt;/sub&gt;], which contains two Fe6 units bridged by the carboxylate arms from the bicine ligands. The complex displays strong antiferromagnetic coupling leading to an S = 0 ground state

    Analyzing Disproportionate Reaction via Comparative Multilingual Targeted Sentiment in Twitter

    Get PDF
    Global events such as terrorist attacks are commented upon in social media, such as Twitter, in different languages and from different parts of the world. Most prior studies have focused on monolingual sentiment analysis, and therefore excluded an extensive proportion of the Twitter userbase. In this paper, we perform a multilingual comparative sentiment analysis study on the terrorist attack in Paris, during November 2015. In particular, we look at targeted sentiment, investigating opinions on specific entities, not simply the general sentiment of each tweet. Given the potentially inflammatory and polarizing effect that these types of tweets may have on attitudes, we examine the sentiments expressed about different targets and explore whether disproportionate reaction was expressed about such targets across different languages. Specifically, we assess whether the sentiment for French speaking Twitter users during the Paris attack differs from English-speaking ones. We identify disproportionately negative attitudes in the English dataset over the French one towards some entities and, via a crowdsourcing experiment, illustrate that this also extends to forming an annotator bias

    Efecto hepatoprotector del insaponificable de los aceites de oliva, linaza y sésamo contra la lesión hepática inducida por tetracloruro de carbono en ratas

    Get PDF
    In the present study, the hepatoprotective activity of the unsaponifiable matter (UNSAP) of olive oil, linseed, and sesame oils against CCl4-induced liver toxicity in rats was investigated. In a preliminary antioxidant study, UNSAP showed pronounced DPPH radical scavenging activity (IC50 6.2-10.8 mg/mL). The constituents of UNSAP were determined by GC-MS. The subcutaneous administration of CCl4, caused liver injury. The hepatoprotective effect of UNSAP was comparable to that of α-tocopherol, a standard antioxidant agent. The co-administration of the investigated UNSAP normalized the activities of serum marker enzymes, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Furthermore, the serum alkaline phosphatase (ALP) activity and hepatic malondialdehyde (MDA) level were found to be alleviated by pre-treatment with the UNSAP. A histopathological evaluation showed marked improvement in the liver of UNSAP- and α-Tocopherol-treated animals. The hepatoprotective effect could be attributed to the antioxidant characteristics of UNSAP.En el presente estudio, se investigó la actividad hepatoprotectora de la materia insaponificable (UNSAP) de los aceites de oliva, linaza y sésamo contra la toxicidad hepática inducida por CCl4 en ratas. En un estudio preliminar de antioxidantes, UNSAP mostró una pronunciada actividad de captación de radicales DPPH (IC50 6.2-10.8 mg / mL). Los constituyentes del UNSAP fueron determinados por GC-MS. La administración de CCl4, por vía subcutánea, causó lesión hepática. El efecto hepatoprotector del UNSAP fue comparable al del α-Tocoferol, un agente antioxidante estándar. La administración conjunta del UNSAP normalizó las actividades de las enzimas marcadoras séricas, alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST). Además, se encontró que la actividad de la fosfatasa alcalina en suero (ALP) y el nivel de malondialdehído hepático (MDA) se mitigan con el tratamiento previo con UNSAP. La evaluación histopatológica mostró una mejoría notable en el hígado de los animales tratados con UNSAP y α-Tocopherol. El efecto hepatoprotector podría atribuirse a las características antioxidantes de UNSAP

    Novel microwell-based spectrophotometric assay for determination of atorvastatin calcium in its pharmaceutical formulations

    Get PDF
    The formation of a colored charge-transfer (CT) complex between atorvastatin calcium (ATR-Ca) as a n-electron donor and 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a π-electron acceptor was investigated, for the first time. The spectral characteristics of the CT complex have been described, and the reaction mechanism has been proved by computational molecular modeling. The reaction was employed in the development of a novel microwell-based spectrophotometric assay for determination of ATR-Ca in its pharmaceutical formulations. The proposed assay was carried out in 96-microwell plates. The absorbance of the colored-CT complex was measured at 460 nm by microwell-plate absorbance reader. The optimum conditions of the reaction and the analytical procedures of the assay were established. Under the optimum conditions, linear relationship with good correlation coefficient (0.9995) was found between the absorbance and the concentration of ATR-Ca in the range of 10-150 μg/well. The limits of detection and quantitation were 5.3 and 15.8 μg/well, respectively. No interference was observed from the additives that are present in the pharmaceutical formulation or from the drugs that are co-formulated with ATR-Ca in its combined formulations. The assay was successfully applied to the analysis of ATR-Ca in its pharmaceutical dosage forms with good accuracy and precision. The assay described herein has great practical value in the routine analysis of ATR-Ca in quality control laboratories, as it has high throughput property, consumes minimum volume of organic solvent thus it offers the reduction in the exposures of the analysts to the toxic effects of organic solvents, and reduction in the analysis cost by 50-fold. Although the proposed assay was validated for ATR-Ca, however, the same methodology could be used for any electron-donating analyte for which a CT reaction can be performed

    CMS Software Distribution on the LCG and OSG Grids

    Full text link
    The efficient exploitation of worldwide distributed storage and computing resources available in the grids require a robust, transparent and fast deployment of experiment specific software. The approach followed by the CMS experiment at CERN in order to enable Monte-Carlo simulations, data analysis and software development in an international collaboration is presented. The current status and future improvement plans are described.Comment: 4 pages, 1 figure, latex with hyperref

    Fog based intelligent transportation big data analytics in the internet of vehicles environment: motivations, architecture, challenges, and critical issues

    Get PDF
    The intelligent transportation system (ITS) concept was introduced to increase road safety, manage traffic efficiently, and preserve our green environment. Nowadays, ITS applications are becoming more data-intensive and their data are described using the '5Vs of Big Data'. Thus, to fully utilize such data, big data analytics need to be applied. The Internet of vehicles (IoV) connects the ITS devices to cloud computing centres, where data processing is performed. However, transferring huge amount of data from geographically distributed devices creates network overhead and bottlenecks, and it consumes the network resources. In addition, following the centralized approach to process the ITS big data results in high latency which cannot be tolerated by the delay-sensitive ITS applications. Fog computing is considered a promising technology for real-time big data analytics. Basically, the fog technology complements the role of cloud computing and distributes the data processing at the edge of the network, which provides faster responses to ITS application queries and saves the network resources. However, implementing fog computing and the lambda architecture for real-time big data processing is challenging in the IoV dynamic environment. In this regard, a novel architecture for real-time ITS big data analytics in the IoV environment is proposed in this paper. The proposed architecture merges three dimensions including intelligent computing (i.e. cloud and fog computing) dimension, real-time big data analytics dimension, and IoV dimension. Moreover, this paper gives a comprehensive description of the IoV environment, the ITS big data characteristics, the lambda architecture for real-time big data analytics, several intelligent computing technologies. More importantly, this paper discusses the opportunities and challenges that face the implementation of fog computing and real-time big data analytics in the IoV environment. Finally, the critical issues and future research directions section discusses some issues that should be considered in order to efficiently implement the proposed architecture

    Ultra-small fatty acid-stabilized magnetite nanocolloids synthesized by in situ hydrolytic precipitation

    Get PDF
    © 2015 Kheireddine El-Boubbou et al. Simple, fast, large-scale, and cost-effective preparation of uniform controlled magnetic nanoparticles remains a major hurdle on the way towards magnetically targeted applications at realistic technical conditions. Herein, we present a unique one-pot approach that relies on simple basic hydrolytic in situ coprecipitation of inexpensive metal salts (Fe&lt;sup&gt;2+&lt;/sup&gt; and Fe&lt;sup&gt;3+&lt;/sup&gt;) compartmentalized by stabilizing fatty acids and aided by the presence of alkylamines. The synthesis was performed at relatively low temperatures (80°C) without the use of high-boiling point solvents and elevated temperatures. This method allowed for the production of ultra-small, colloidal, and hydrophobically stabilized magnetite metal oxide nanoparticles readily dispersed in organic solvents. The results reveal that the obtained magnetite nanoparticles exhibit narrow size distributions, good monodispersities, high saturation magnetizations, and excellent colloidal stabilities. When the [fatty acid]: [Fe] ratio was varied, control over nanoparticle diameters within the range of 2-10 nm was achieved. The amount of fatty acid and alkylamine used during the reaction proved critical in governing morphology, dispersity, uniformity, and colloidal stability. Upon exchange with water-soluble polymers, the ultra-small sized particles become biologically relevant, with great promise for theranostic applications as imaging and magnetically targeted delivery vehicles

    Generation of polyclonal antibody with high avidity to rosuvastatin and its use in development of highly sensitive ELISA for determination of rosuvastatin in plasma

    Get PDF
    In this study, a polyclonal antibody with high avidity and specificity to the potent hypocholesterolaemic agent rosuvastatin (ROS) has been prepared and used in the development of highly sensitive enzyme-linked immunosorbent assay (ELISA) for determination of ROS in plasma. ROS was coupled to keyhole limpt hemocyanin (KLH) and bovine serum albumin (BSA) using carbodiimide reagent. ROS-KLH conjugate was used for immunization of female 8-weeks old New Zealand white rabbits. The immune response of the rabbits was monitored by direct ELISA using ROS-BSA immobilized onto microwell plates as a solid phase. The rabbit that showed the highest antibody titer and avidity to ROS was scarified and its sera were collected. The IgG fraction was isolated and purified by avidity chromatography on protein A column. The purified antibody showed high avidity to ROS; IC50 = 0.4 ng/ml. The specificity of the antibody for ROS was evaluated by indirect ELISA using various competitors from the ROS-structural analogues and the therapeutic agents used with ROS in a combination therapy. The proposed ELISA involved a competitive binding reaction between ROS, in plasma sample, and the immobilized ROS-BSA for the binding sites on a limited amount of the anti-ROS antibody. The bound anti-ROS antibody was quantified with horseradish peroxidase-labeled second anti-rabbit IgG antibody (HRP-IgG) and 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate for the peroxidase enzyme. The concentration of ROS in the sample was quantified by its ability to inhibit the binding of the anti-ROS antibody to the immobilized ROS-BSA and subsequently the color intensity in the assay wells. The assay enabled the determination of ROS in plasma at concentrations as low as 40 pg/ml
    corecore