4,509 research outputs found

    Potentiometric detection of low-levels of sulfamethazine in milk and pharmaceutical formulations using novel plastic membrane sensors

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    Novel potentiometric sensors for selective screening of sulfamethazine (SMZ) in pharmaceutical preparations and milk samples are reported. The sensor membranes were made from PVC matrix doped with magnesium(II)-, manganese(II)- and dichlorotin (IV)-phthalocyanines as ionophores and aliquat-336 and nitron/SMZ ion-pair complex as ion exchangers. These sensors revealed fast, stable and near-Nernstian anionic response for the singly charged sulfamethazine anion over the concentration range 10-2 - 10-5 M. The sensors exhibited good selectivity towards SMZ over most known anions, excipients and diluents commonly added in drug preparations. Validation of the proposed methods was demonstrated via evaluating the detection limit, linear response range, accuracy, precision (within-day repeatability) and between-day-variability. The sensors are easily interfaced with a double channel flow injection system and used for continuous monitoring of SMZ in drug formulations, spiked milk samples and biological tissues. The method offers the advantages of design simplicity, results accuracy, and automation feasibility

    Early Effects on the Morphology of Mouse Small Intestine of Single or Combined Modality Treatment with Hyperthermia and X-Irradiation

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    This study describes the effects of hyperthermia and X-irradiation on the morphological appearance of normal, at risk tissues in the ileum of the mouse. The early morphological effects day after a combined modality treatment are compared with those due to either hyperthermia or X-irradiation given alone. The response was assessed qualitatively and semiquantitatively using scanning electron microscopy and a villous scoring technique. Early post-irradiation effects on topography did not differ significantly from those observed after small intestine exteriorisation without treatment. The villous scores for the combined modality treatments reflected greater damage than would be expected from the sum of villous scores for each modality treatment on its own. This suggests that the combined modality treatment had a synergistic or enhancing effect. A 4 hour time interval between the two treatments did not seem to reduce the enhancing effect. Further studies are required to investigate the effects of fractionated combined treatment

    Frontline Science: Antagonism between regular and atypical Cxcr3 receptors regulates macrophage migration during infection and injury in zebrafish

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    The CXCR3-CXCL11 chemokine-signaling axis plays an essential role in infection and inflammation by orchestrating leukocyte trafficking in human and animal models, including zebrafish. Atypical chemokine receptors (ACKRs) play a fundamental regulatory function in signaling networks by shaping chemokine gradients through their ligand scavenging function, while being unable to signal in the classic G-protein-dependent manner. Two copies of the CXCR3 gene in zebrafish, cxcr3.2 and cxcr3.3, are expressed on macrophages and share a highly conserved ligand-binding site. However, Cxcr3.3 has structural characteristics of ACKRs indicative of a ligand-scavenging role. In contrast, we previously showed that Cxcr3.2 is an active CXCR3 receptor because it is required for macrophage motility and recruitment to sites of mycobacterial infection. In this study, we generated a cxcr3.3 CRISPR-mutant to functionally dissect the antagonistic interplay among the cxcr3 paralogs in the immune response. We observed that cxcr3.3 mutants are more susceptible to mycobacterial infection, whereas cxcr3.2 mutants are more resistant. Furthermore, macrophages in the cxcr3.3 mutant are more motile, show higher activation status, and are recruited more efficiently to sites of infection or injury. Our results suggest that Cxcr3.3 is an ACKR that regulates the activity of Cxcr3.2 by scavenging common ligands and that silencing the scavenging function of Cxcr3.3 results in an exacerbated Cxcr3.2 signaling. In human, splice variants of CXCR3 have antagonistic functions and CXCR3 ligands also interact with ACKRs. Therefore, in zebrafish, an analogous regulatory mechanism appears to have evolved after the cxcr3 gene duplication event, through diversification of conventional and atypical receptor variants

    Functionality of Inorganic Nanostructured Materials onto Wool Fabric

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    Silver nanoparticles (AgNPs) were prepared through chemical reduction method and characterized by UV-Vis absorption spectra to examine its formation with different AgNO3 and sodium borohydride concentrations and by transmission electron microscope (TEM) to evaluate its particle size and size distribution. The wool fabric was first treated separately with AgNPs and titanium dioxide nanoparticles (TiO2NPs) and then dyed with C.I. Acid Orange 74 (AO74). The dye uptake of pre-treated wool fabric with nanoparticles was compared to conventional dyeing of wool. The existence of AgNPs and TiO2NPs on wool fabric during acid dyeing increases the dye uptake up to 27 and 39%, respectively. The dyeing kinetic of wool fabric was positively affected by treating with AgNPs and TiO2NPs. Also, the activation energy of AO74 diffusion was calculated before and after NPs-treatment that confirms the physicsorption dyeing process. The NPs-treatment leads to produce a wool fabric with excellent antibacterial and photocatalytic properties for TiO2NPs-treated wool fabric and very good antibacterial and good photocatalytic properties for AgNPs-treated wool fabric. In addition, NPs-treatment has no adverse effects on fastness properties of the functionalized dyed wool fabric. Keywords: Silver nanoparticles, Titanium dioxide nanoparticles, Wool, Acid dyeing

    Facies and geochemistry of non-marine gypsum, EMISAL, Egypt

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    Diverse gypsum facies in terms of crystal size and morphology are deposited in a shallow, non-marine, sulfate-enriched, semi-closed, perennial evaporite basin. These gypsum facies were deposited in intimate association with cyanobacterial mats. Facies analyses and geochemistry revealed two distinct primary facies, based on gypsum fabric; massive selenite, and laminated gypsum varieties. The massive selenite facies is composed of clusters of single and twinned crystals along (100), with upward pointing re-entrant angle. The laminated gypsum varies from rhythmically laminated grass-like selenite to gypsum microbialite (stromatolite). The change from massive selenite to laminated gypsum facies implies fluctuation in lateral and vertical salinity profiles, seasonal brine concentrations and wind action. Post-depositional changes in the form of dissolution, slight to moderate crystal deformation and recrystallization to anhydrite are evaluated. We develop a qualitative model for the depositional basin and facies distribution in order to simulate ancient analogues

    Structural Changes in Mouse Small Intestinal Villi Following Lower Body Hyperthermia

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    Heating an exteriorised loop of mouse small intestine resulted in marked changes in the shape of the villi as reported earlier. However, the exteriorisation techniques resulted in non-uniformity in both temperature and effect around circumference of intestine and, in addition, the extent to which handling contributed to the observed damage was not known. The work has therefore been extended using lower-body heating in the temperature range 37.5° - 43.0°C. Heating in the temperature range 37.5° to 41.0°C produced minimal to moderate structural changes, manifested as scattered, vertically collapsed villi amongst predominantly normal villi. No villi showed conical or rudimentary forms of collapse. Such villi were, however, seen after heating at 41.5°C and were greatly increased in number after heating at 42.0°C. The most severe damage was observed after heating at 43.0°C. Although the lower body heating method gave information which was less complicated by technical considerations, the hyperthermic damage observed was qualitatively similar to that previously seen following local administration of hyperthermia to an exteriorised loop of intestine. Direct quantitative comparisons between the two methods of heating are difficult because of differences in equilibration time and temperature. However, using a comparable heating time, less damage was scored following the exteriorisation technique compared with in situ heating

    Consideraciones taxonómicas sobre algunos taxones egipcios de Capparis y géneros relacionados (Capparaceae) a partir de RAPDs

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    Taxonomic considerations among and within some Egyptian taxa of Capparis and related genera (Capparaceae) as revealed by RAPD fingerprinting.- This investigation was carried out to assess the taxonomic relationships among eight taxa of the Egyptian members of Capparaceae based on random amplified polymorphic DNA markers, and to compare the results with those obtained from morphological studies. A total of 46 bands were scored for three RAPD primers corresponding to an average of 15.3 bands per primer. The three primers (A03, A07 and A09) revealed eight polymorphic RAPD markers among the studied taxa ranging in size from 200 bp to 1000 bp. Jaccard’s coefficient of similarity varied from 0.28 to 0.84, indicative of high level of genetic variation among the genotypes studied. UPGMA cluster analysis indicated three distinct clusters, one comprised Cleome amblyocarpa and Gynandropsis gynandra, while another included two clusters at 0.74 phenon line; one for Capparis decidua, and the other for Capparis sinaica and all varieties of Capparis spinosa. The four varieties of Capparis spinosa were segregated at 0.84 phenon line. However, one of these varieties was more closely related to Capparis sinaica than to the other three varieties of C. spinosa. The RAPD analysis reported here confirms previous studies based on morphological markers.Consideraciones taxonómicas sobre algunos taxones egipcios de Capparis y géneros relacionados (Capparaceae) a partir de RAPDs.- El objetivo de este trabajo es investigar las relaciones taxonómicas entre ocho taxones pertenecientes a las Capparaceae en base a marcadores de tipo RAPD, y comparar los resultados con los obtenidos previamente en estudios morfológicos. Se han contabilizado un total de 46 bandas para tres pares de cebadores, con una media de 15,3 bandas por cebador. Los tres pares de cebadores (A03, A07 y A09) revelan ocho marcadores polimórficos entre los taxones estudiados, de entre 200 y 1000 pares de bases. El coeficiente de similaridad de Jaccard varía entre 0,28 y 0,84, indicativo de un alto nivel de variación genética entre los genotipos estudiados. El análisis UPGMA muestra tres grupos distintos, el primero comprende Cleome amblyocarpa y Gynandropsis gynandra, mientras que el segundo incluye dos grupos a la altura del valor 0,74 del dendrograma: uno se corresponde con Capparis decidua, y el otro comprende Capparis sinaica y todas las variedades de Capparis spinosa. Las cuatro variedades de C. spinosa se segregan a la altura del valor 0,84 del dendrograma. Sin embargo, una de estas variedades está más relacionada con C. sinaica que con las otras variedades de C. spinosa. El análisis de RAPD confirma los resultados de estudios anteriores basados en caracteres morfológicos

    Detection and tracking of discrete phenomena in sensor-network databases

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    This paper introduces a framework for Phenomena Detection and Tracking (PDT, for short) in sensor network databases. Examples of detectable phenomena include the propagation over time of a pollution cloud or an oil spill region. We provide a crisp definition of a phenomenon that takes into consideration both the strength and the time span of the phenomenon.We focus on discrete phenomena where sensor readings are drawn from a discrete set of values, e.g., item numbers or pollutant IDs, and we point out how our work can be extended to handle continuous phenomena. The challenge for the proposed PDT framework is to detect as much phenomena as possible, given the large number of sensors, the overall high arrival rates of sensor data, and the limited system resources. Our proposed PDT framework uses continuous SQL queries to detect and track phenomena. Execution of these continuous queries is performed in three phases; the joining phase, the candidate selection phase, and the grouping/output phase. The joining phase employs an in-memory multi-way join algorithm that produces a set of sensor pairs with similar readings. The candidate selection phase filters the output of the joining phase to select candidate join pairs, with enough strength and time span, as specified by the phenomenon definition. The grouping/ output phase constructs the overall phenomenon from the candidate join pairs. We introduce two optimizations to increase the likelihood of phenomena detection while using less system resources. Experimental studies illustrate the performance gains of both the proposed PDT framework and the proposed optimizations

    The Role of Nano-Technology in Sustainable Construction: A Case Study of Using Nano Granite Waste Particles in Cement Mortar

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    Better understanding of the properties of cement-based materials, one of the most widely used building materials, at the nano-scale is crucial to improve its functionality in the built environment. This paper presents areas of using nano-materials in improving the characteristics of cement-based materials as well as introducing a new role of nano-technology together with waste management in enhancing the concept of sustainable construction. A case study on the use of nano-granite waste particles as a replacement of cement and fine aggregate in mortar production is presented. The research concluded that replacing 5% cement and 10% sand with nano-granite waste in the mortar mix increased the compressive strength of the green mortar by 41% compared to that of the control mix (CM). SEM images reinforced this result as the green mortar mix showed maximum density and minimum micro cracks and number of pores. A comparative study between the green mortar and traditional mortar was carried out using sustainability indicators to examine the environmental, social and economic implications. The environmental and social attributes showed a saving of 10% in the field of resource consumption, whereas savings in energy consumption and CO2 emissions reached 5%. The economic field showed saving of 6.5% indicating promising results in enhancing the sustainable construction industry
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