75 research outputs found

    Determination of isoquinoline alkaloids contents in two Algerian species of Fumaria (Fumaria capreolata and Fumaria bastardi)

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    This paper describes a fast and efficient procedure to separate and identify isoquinoline alkaloids from methalonic extract of two Algerian Fumaria (Fumariacea) species (Fumaria capreolata L. and Fumariabastardi L.) used in traditional medicine in cases of hepatobiliary disfunction and diarrhoea. Total quinolizidine alkaloid contents were 426 mg/100 g (F. capreolata) and 521 mg/100 g (F. bastardi). Theisoquinoline alkaloids, stylopine, protopine, fumaritine, fumaricine, fumarophycine, fumariline and fumarofine were determined by gas chromatography – mass spectrometry (GC-MS) in aerial parts ofboth Fumaria capreolata and Fumaria bastardi. In the first species, an ester of phtalic acid was identified, and in the second species a peak seems to be a benzophenanthridine, probably a dehydro derivative and three other peaks which were identified as phtalidisoquinoline, one of them seems to bedihydrofumariline. The chemotaxonomic significance of the results is discussed

    The vortex motion and the magnetization study in YBa2Cu3O7-d single crystal

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    We have investigated the vortex motion and the magnetization of high critical temperature superconductors YBa2Cu3O7-d Measurements were made using a vibrating sample magnetometer technique. Several magnetization hysteresis cycles have been obtained for different angles, θ, between the applied magnetic field, H, and the crystallographic c-axis. For T = 30 K we observed a central peak and for T = 80 K we observed a second peak or "fishtail".We have investigated the vortex motion and the magnetization of high critical temperature superconductors YBa2Cu3O7-d Measurements were made using a vibrating sample magnetometer technique. Several magnetization hysteresis cycles have been obtained for different angles, θ, between the applied magnetic field, H, and the crystallographic c-axis. For T = 30 K we observed a central peak and for T = 80 K we observed a second peak or "fishtail"

    The critical current density and the vortex pinning in high quality YBa2Cu3O7-d thin films

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    We have measured the critical current density Jc of high quality c-axis oriented YBa2Cu3O7-d thin films. Measurements were performed for various magnetic field and temperature values, and as a function of the angle q between the c-axis and the applied magnetic field direction. A maximum of the critical current density was obtained when the flux lines are aligned along the CuO planes (q = 90°); another maximum in Jc was also observed when the magnetic field is adjusted parallel to the c-axis. We attribute these effects to different, intrinsic and extrinsic, pinning mechanisms of vortices in the sample.We have measured the critical current density Jc of high quality c-axis oriented YBa2Cu3O7-d thin films. Measurements were performed for various magnetic field and temperature values, and as a function of the angle q between the c-axis and the applied magnetic field direction. A maximum of the critical current density was obtained when the flux lines are aligned along the CuO planes (q = 90°); another maximum in Jc was also observed when the magnetic field is adjusted parallel to the c-axis. We attribute these effects to different, intrinsic and extrinsic, pinning mechanisms of vortices in the sample

    Novel integrative genomic tool for interrogating lithium response in bipolar disorder

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    We developed a novel integrative genomic tool called GRANITE (Genetic Regulatory Analysis of Networks Investigational Tool Environment) that can effectively analyze large complex data sets to generate interactive networks. GRANITE is an open-source tool and invaluable resource for a variety of genomic fields. Although our analysis is confined to static expression data, GRANITE has the capability of evaluating time-course data and generating interactive networks that may shed light on acute versus chronic treatment, as well as evaluating dose response and providing insight into mechanisms that underlie therapeutic versus sub-therapeutic doses or toxic doses. As a proof-of-concept study, we investigated lithium (Li) response in bipolar disorder (BD). BD is a severe mood disorder marked by cycles of mania and depression. Li is one of the most commonly prescribed and decidedly effective treatments for many patients (responders), although its mode of action is not yet fully understood, nor is it effective in every patient (non-responders). In an in vitro study, we compared vehicle versus chronic Li treatment in patient-derived lymphoblastoid cells (LCLs) (derived from either responders or non-responders) using both microRNA (miRNA) and messenger RNA gene expression profiling. We present both Li responder and non-responder network visualizations created by our GRANITE analysis in BD. We identified by network visualization that the Let-7 family is consistently downregulated by Li in both groups where this miRNA family has been implicated in neurodegeneration, cell survival and synaptic development. We discuss the potential of this analysis for investigating treatment response and even providing clinicians with a tool for predicting treatment response in their patients, as well as for providing the industry with a tool for identifying network nodes as targets for novel drug discovery

    How much is enough? Approaches to public participation in shale gas regulation across England, France, and Algeria

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    We examine ‘fracking’ for shale gas extraction in England, France, and Algeria, framed from the perspective of level of acceptance by communities and general public. We explore the extent to which public participation in decision-making should play a role in fracking regulation, and evaluate whether the level of public participation matches the legal requirements. Our position on the adequacy of fracking regulation is from the perspective of the public dissenter, outlining a legal and normative basis for public participation in decision-making on fracking. We highlight relevant laws and policies to understand and evaluate adequacy of relevant regulatory processes. We offer strong yet nuanced argumentation, creating space for further discussion by academics, the public, regulators, local decision-makers, fracking companies and others. This is not a typical social-psychology, legal, sociology, or human geography research paper, as we take a position from the beginning: that the public ought to be involved in decisions related to the regulation of fracking, and argue that we validate our approach by supporting our claims throughout the work

    Theoretical investigation of new MgS-ZnSe structures

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    International audienceheoretical studies of the excitonic properties for different designs of MgS-ZnSe structures are presented. Excitonic binding energies are calculated for single quantum wells. For MgS-ZnSe superlattices, the energy of electron-hole transitions are evaluated and compared with the experimental photoluminescence spectra

    Algerian mint species: high performance thin layer chromatography quantitative determination of rosmarinic acid and in vitro inhibitory effects on linoleic acid peroxidation

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    Objective: To determine the quantitative paremeters of rosmarinic acid in Algerian mints, Mentha spicata L. (M. spicata), Mentha pulegium L. and Mentha rotundifolia (L.) Huds by high performance thin layer chromatography (HPTLC)-densitometric method and screen the effects of these plant extracts on linoleic acid peroxidation. Methods: The analyses were performed on HPTLC silica gel 60 F254 plates with chloroform: acetone: formic acid (75:16.5:8.5, v/v) as the mobile phase. Rosmarinic acid was determined in UV at 365 nm and fluorescence at λexc 325 nm with a 550 nm filter, respectively. The effects of plants extracts on linoleic acid peroxidation were measured by an indirect in vitro colorimetric method. Results: Chromatographic resolution permitted reliable quantification in both measurement modes and calibration curves were linear in a range of 150-1 000 ng/spot. M. spicata was found to contain significantly higher concentrations of rosmarinic acid. The densitometric quantification allowed the analysis of many samples in a short time with reasonable precision (total precision for Mentha spp extracts, 5.1% and 5.8% for UV and fluorescence detection, respectively). The HPTLC data, allied to assays of linoleic acid peroxidation prevention, suggested the potential of M. spicata (52% Trolox® equivalents) as a natural source for inhibitors of lipid peroxidation. Conclusions: Densitometry can be used for routine determination and quality control of rosmarinic acid in herbal and formulations containing Mentha species.info:eu-repo/semantics/publishe
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