185 research outputs found

    Chemical composition of the essential oil of Brachyapium dichotomum (L.) Maire

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    The essential oil obtained by hydrodistillation from the aerial parts of Brachyapium dichotomum (L.) Maire (Apiaceae), was analyzed by GC-MS for the first time. Sixty-two compounds were detected, accounting for 96.1% of the total oil, which is characterized by a high content of hydrocarbons derivatives of mono- and sesquiterpenes (80.3%). The main constituents were α-pinene (36.5%), germacrene D (17.9%), dill apiole (6.7%) and myristicin (3.5%)

    Glutamate induces autophagy via the two-pore channels in neural cells

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    NAADP (nicotinic acid adenine dinucleotide phosphate) has been proposed as a second messenger for glutamate in neuronal and glial cells via the activation of the lysosomal Ca2+ channels TPC1 and TPC2. However, the activities of glutamate that are mediated by NAADP remain unclear. In this study, we evaluated the effect of glutamate on autophagy in astrocytes at physiological, non-toxic concentration. We found that glutamate induces autophagy at similar extent as NAADP. By contrast, the NAADP antagonist NED-19 or SiRNA-mediated inhibition of TPC1/2 decreases autophagy induced by glutamate, confirming a role for NAADP in this pathway. The involvement of TPC1/2 in glutamate-induced autophagy was also confirmed in SHSY5Y neuroblastoma cells. Finally, we show that glutamate leads to a NAADP-dependent activation of AMPK, which is required for autophagy induction, while mTOR activity is not affected by this treatment. Taken together, our results indicate that glutamate stimulates autophagy via NAADP/TPC/AMPK axis, providing new insights of how Ca2+ signalling glutamate-mediated can control the cell metabolism in the central nervous system

    Experimental and Finite Element Modal Analyses of Planar Mechanisms With Three- Dimensional Geometries

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    Background and Objective In designing a high-performance mechanism for proper dynamic characteristics, its natural frequencies should be a key design factor because they influence its operating speed and the amplitudes and settling times of its vibrations. Natural frequencies of a planar mechanism system is influenced by the inertia and flexibiUty of the links and joints, link offsets, and components comprising the drive and load shafts. The geometry of a kinematically planar mechanism is essentially three dimension (3D) due to the inevitable presence of link offsets dictated by the task and geometric constraints. Link offsets increase the flexibility of the mechanism system, lowers its natural frequency and may cause out-of-plane vibrations to dominate. Furthermore, the inherent compliance and inertia of the drive and load train components such as the driving unit, couphngs, transmission mechanisms, and connecting shafts may influence linkage response by lowering its natural frequencies. Therefore, a reliable model of a planar mechanism should include the influence of all its components rather than its links only

    Numerical Investigations on the Fluid Behavior in the Near Wake of an Experimental Wind Turbine Model in the Presence of the Nacelle

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    Accurate predictions of the near wake of horizontal-axis wind turbines are critical in estimating and optimizing the energy production of wind farms. Consequently, accurate aerodynamic models of an isolated wind turbine are required. In this paper, the steady-state flow around an experimental horizontal-axis wind turbine (known as the MEXICO model) is investigated using full-geometry computational fluid dynamics (CFD) simulations. The simulations are performed using Reynolds-Averaged Navier-Stokes (RANS) equations in combination with the transitional k-kl-w turbulence model. The multiple reference frame (MRF) approach is used to allow the rotation of the blades. The impacts of the nacelle and blade rotation on the induction region and near wake are highlighted. Simulation cases under attached and detached flow conditions with and without the nacelle were compared to the detailed particle image velocimetry (PIV) measurements. The axial and radial flow behaviors at the induction region have been analyzed in detail. This study attempts to highlight the nacelle effects on the near wake flow and on numerical prediction accuracy under various conditions, as well as the possible reasons for these effects. According to simulation results, the rotation of blades dominates the near wake region, and including the nacelle geometry can improve both axial and radial flow prediction accuracy by up to 15% at high wind speeds. At low wind speeds, the nacelle effects can be ignored. The presence of the nacelle has also been shown to increase flow separation at the trailing edges of the blade airfoils, increasing both root and tip vorticities. Finally, small nacelle diameters are recommended to reduce flow separation on the blades and increase the average velocity downstream of the rotor, thereby optimizing wind farm output power

    Leiomyome agressif naso-sinusien : a propos d’un cas et revue de la litterature

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    Introduction : Les léiomyomes sont des tumeurs bénignes issues des fibres musculaires lisses. La localisation au niveau des cavités nasosinusiennes est très rare.Cas clinique : Il s’agit d’une patiente âgée de 59 ans, qui a consulté pour obstruction nasale et épistaxis gauches. L’endoscopie nasale a montré une formation comblant totalement la fosse nasale gauche. L’imagerie (TDM, IRM) a objectivé un volumineux processus expansif tissulaire naso-ethmoïdo-maxillaire, avec extension intra-orbitaire et endocrânienne. La biopsie confirmé qu’il s’agit d’un léiomyome à localisation nasosinusienne. La patiente a été opérée par voie paralatéronasale élargie. Elle a eu une exérèse tumorale complète et une reconstruction de la perte de substance osseuse par autogreffe. Les suites opératoires étaient simples. Aucune récidive n’a été notée après un recul de 1 an.Conclusion : La localisation nasosinusienne du léiomyome est très rare. L’imagerie est indispensable dans le cadre du bilan d’extension loco-régional. Seul une exérèse chirurgicale complète permettra d’éviter toute récidive aussi bien à court qu’à long terme.Mots-clés : léiomyome, fosses nasales, sinus, tomodensitométrie, imagerie par résonance magnétique, chirurgie sinusienneIntroduction: Leiomyomas are benign tumors arising from smooth muscle fibers. The location at the sinonasal cavities is very rare.Case report: This is a female patient aged 59, who consulted for left nasal obstruction and epistaxis. Nasal endoscopy showed a tumor completely filling the left nasal cavity. Imaging (CT, MRI) has objectified a large expansive tissularnaso-maxillary-ethmoidal process with intraorbital and intracranial extension. The biopsy confirmed that this was a leiomyoma with sinonasal localization. The patient was operated by extended paralatéronasale approach. She had a complete tumor resection and reconstruction of the bone defect with autograft. The postoperative course was uneventful. No recurrence was observed after a follow-up period of 1 year.Conclusion: The sinonasal location of leiomyoma is very rare. Imaging is essential for locoregional staging. Only a complete surgical resection will prevent any recurrence both in short and long term.Keywords : leiomyoma, nasal fossae, sinus, computed tomography, magnetic resonance imaging, sinusal surger

    Preliminary petrological inferences on the high-grade metamorphic rocks exhumed by the South Rif Thrust, Prerif, Northern Morocco

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    The exhumation of deep crustal rocks along major shear zones is common, yet a highly debated subject, particularly when occurring during recent tectonic events. This is the case of the South Rif Thrust (SRT), a significant shear zone analogous to those described at the Betic Cordillera in Spain. The SRT separates two major geodynamic domains in Northern Morocco: a) the Prerif, to the North, mostly composed of Miocenic sedimentary units on top of a stratigraphic sequence continuously deposited since the Triassic; and b) the Western Meseta, to the South, mostly composed of Paleozoic metasedimentary units, correlated with the Iberian Variscan Belt [1]. Associated to the SRT, and exhumed by its activity, there is a dismembered and exotic high-grade metamorphic belt representative of the middle and lower crust. Also in this region, several thermo-mineral waters occur, whose deep circulation can be traced back to the SRT [2]. Detailed geological mapping, structural, stratigraphic and petrographic analyses on this dismembered and highly deformed exotic sequence reveal the presence of low- to high-grade metasediments (including migmatites and felsic granulites), but mostly high-grade metabasic and basic rocks, including amphibolites, mafic granulites and gabbros. Preliminary geothermobarometry in the mafic granulites provides an important characterization of the infra-crustal conditions of the pre-Alpine geodynamics and of the activity and exhumation along the SRT since the Miocene: a) the mafic granulites endured M1 metamorphic peak conditions of T = 1030 ºC at P = 8.5 kbar, which is consistent with typical conductive continental crust geothermal gradients (~30 ºC.km-1); b) M2 retrogression occurred by near isothermal decompression at T = 820 ºC and P = 3.5 kbar, implying an initial vertical uplift of >18 km of the granulite-facies rocks to very shallow levels; c) during this period, the geothermal gradient in the region surpassed 60 ºC.km-1; d) exhumation and retrogression continued by almost isobaric cooling at T < 750 ºC and P = 1.7 – 3.0 kbar with an M3 amphibolitization of the granulites after late water inflow. The overall metamorphic evolution of these deep crustal rocks is compatible with a clockwise P-T path, involving initial fast tectonic exhumation, followed by thermal readjustment to shallower levels. This is consistent with the currently observed geothermal gradients in the area (≤ 42 ºC.km-1) [2] which may still be a reflection of the events during the Miocene. These petrological constrains on the tectonic processes associated with the exhumation of this lower crust segment and the activity of the SRT during the closure of the Alboran Basin are key to understanding the circulation of deep hot waters, which are an important part of the economy of this region in Northern Morocco.publishe

    A cyclopalladated complex interacts with mitochondrial membrane thiol-groups and induces the apoptotic intrinsic pathway in murine and cisplatin-resistant human tumor cells

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    <p>Abstract</p> <p>Background</p> <p>Systemic therapy for cancer metastatic lesions is difficult and generally renders a poor clinical response. Structural analogs of cisplatin, the most widely used synthetic metal complexes, show toxic side-effects and tumor cell resistance. Recently, palladium complexes with increased stability are being investigated to circumvent these limitations, and a biphosphinic cyclopalladated complex {Pd<sub>2 </sub>[<it>S<sub>(-)</sub></it>C<sup>2</sup>, N-dmpa]<sub>2 </sub>(ÎĽ-dppe)Cl<sub>2</sub>} named C7a efficiently controls the subcutaneous development of B16F10-Nex2 murine melanoma in syngeneic mice. Presently, we investigated the melanoma cell killing mechanism induced by C7a, and extended preclinical studies.</p> <p>Methods</p> <p>B16F10-Nex2 cells were treated <it>in vitro </it>with C7a in the presence/absence of DTT, and several parameters related to apoptosis induction were evaluated. Preclinical studies were performed, and mice were endovenously inoculated with B16F10-Nex2 cells, intraperitoneally treated with C7a, and lung metastatic nodules were counted. The cytotoxic effects and the respiratory metabolism were also determined in human tumor cell lines treated <it>in vitro </it>with C7a.</p> <p>Results</p> <p>Cyclopalladated complex interacts with thiol groups on the mitochondrial membrane proteins, causes dissipation of the mitochondrial membrane potential, and induces Bax translocation from the cytosol to mitochondria, colocalizing with a mitochondrial tracker. C7a also induced an increase in cytosolic calcium concentration, mainly from intracellular compartments, and a significant decrease in the ATP levels. Activation of effector caspases, chromatin condensation and DNA degradation, suggested that C7a activates the apoptotic intrinsic pathway in murine melanoma cells. In the preclinical studies, the C7a complex protected against murine metastatic melanoma and induced death in several human tumor cell lineages <it>in vitro</it>, including cisplatin-resistant ones. The mitochondria-dependent cell death was also induced by C7a in human tumor cells.</p> <p>Conclusions</p> <p>The cyclopalladated C7a complex is an effective chemotherapeutic anticancer compound against primary and metastatic murine and human tumors, including cisplatin-resistant cells, inducing apoptotic cell death via the intrinsic pathway.</p

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
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