Search results for "SUPPORTS"

showing 10 items of 26 documents

Gated mesoporous silica nanoparticles for the controlled delivery of drugs in cancer cells

2015

In recent years, mesoporous silica nanoparticles (MSNs) have been used as effective supports for the development of controlled-release nanodevices that are able to act as multifunctional delivery platforms for the encapsulation of therapeutic agents, enhancing their bioavailability and overcoming common issues such as poor water solubility and poor stability of some drugs. In particular, redox-responsive delivery systems have attracted the attention of scientists because of the intracellular reductive environment related to a high concentration of glutathione (GSH). In this context, we describe herein the development of a GSH-responsive delivery system based on poly(ethylene glycol)- (PEG-)…

INGENIERIA DE LA CONSTRUCCIONCell SurvivalIntracellular SpaceNanoparticleNanotechnologyAntineoplastic AgentsCONTROLLED-RELEASETRIGGERED RELEASEPolyethylene Glycolschemistry.chemical_compoundINORGANIC NANOPARTICLESQUIMICA ORGANICASYSTEMSPEG ratioQUIMICA ANALITICAElectrochemistrymedicinePOLYMER HYBRID NANOPARTICLESGLUTATHIONEBIOQUIMICA Y BIOLOGIA MOLECULARHumansGeneral Materials ScienceDoxorubicinSpectroscopyDrug CarriersENHANCED PERMEABILITYQUIMICA INORGANICASurfaces and InterfacesGlutathioneIN-VITROMesoporous silicaCondensed Matter PhysicsSilicon DioxideControlled releaseGUEST MOLECULESBioavailabilityDrug LiberationchemistryDoxorubicinDelayed-Action PreparationsDrug DesignNanoparticlesPhenazinesSUPPORTSEthylene glycolOxidation-ReductionPorositymedicine.drugHeLa Cells

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Glucose-triggered release using enzyme-gated mesoporous silica nanoparticles.

2013

[EN] A new gated nanodevice design able to control cargo delivery using glucose as a trigger and cyclodextrin-modified glucose oxidase as a capping agent is reported.

INGENIERIA DE LA CONSTRUCCIONDelivery SystemGuest moleculesSupportsSilicon dioxideCarbon nanotubesResponsive controlled releaseNanoparticleNanotechnologyCatalysischemistry.chemical_compoundGlucose OxidaseQUIMICA ORGANICAQUIMICA ANALITICAMaterials ChemistryOrganometallic CompoundsTriggered releaseGlucose oxidaseHydrogen peroxideColoring AgentsNanodevicechemistry.chemical_classificationbiologyQUIMICA INORGANICAMetals and AlloysGeneral ChemistryMesoporous silicaHydrogen peroxideSilicon DioxideSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsEnzymeGlucosechemistryCeramics and Compositesbiology.proteinBiophysicsNanoparticlesPorosityChemical communications (Cambridge, England)

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Nanoparticles of AlTiZr mixed oxides as support of hydrodesulfurizaton catalysts: Synthesis and characterisation

2012

Abstract TiAlZr mixed oxides, synthesized using sol–gel method, were characterized and used as supports of hydrodesulfurization catalysts (12 wt% Mo) prepared by impregnation either with molybdenum heteropolyacid H3PMo12O40 or its cobalt salt Co1.5PMo12O40. Structure, morphology and textural properties of oxides and catalysts were characterized using X-ray powder diffraction (XRD), Raman spectroscopy, Nitrogen adsorption porosimetry, TEM-EDS, temperature-programmed desorption (TPD) and temperature-programmed reduction (TPR) techniques. Activity of the catalytic systems was tested in thiophene hydrodesulfurization (HDS). No formation of a new oxide phase was revealed in the synthesized mixed…

Materials scienceMechanical EngineeringInorganic chemistryMetals and AlloysOxidechemistry.chemical_elementCatalysisMixed oxides supports Sol–gel process Co-Mo-P-catalysts Thiophene hydrodesulfurizationchemistry.chemical_compoundchemistryMechanics of MaterialsMolybdenumDesorptionMaterials ChemistryThiopheneCobaltHydrodesulfurizationSol-gelSettore CHIM/02 - Chimica Fisica

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On the moving load problem in Euler–Bernoulli uniform beams with viscoelastic supports and joints

2016

This paper concerns the vibration response under moving loads of Euler–Bernoulli uniform beams with translational supports and rotational joints, featuring Kelvin–Voigt viscoelastic behaviour. Using the theory of generalized functions to handle the discontinuities of the response variables at the support/joint locations, exact beam modes are obtained from a characteristic equation built as determinant of a (Formula presented.) matrix, for any number of supports/joints. Based on pertinent orthogonality conditions for the deflection modes, the response under moving loads is built in the time domain by modal superposition. Remarkably, all response variables are built in a closed analytical for…

Modal superpositionViscoelastic behaviourCharacteristic equationComputational Mechanics02 engineering and technologyClassification of discontinuities01 natural sciencesVibration responseOrthogonality conditionsymbols.namesakeBernoulli's principle0203 mechanical engineeringDeflection (engineering)0103 physical sciencesViscoelastic supports010301 acousticsMathematicsGeneralized functionMechanical EngineeringMathematical analysisCharacteristic equationMoving loadAnalytical formGeneralized function020303 mechanical engineering & transportsEuler's formulasymbolsBeam (structure)Acta Mechanica

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Encapsulation of folic acid in different silica porous supports: A comparative study.

2016

Although folic acid is essential to numerous bodily functions, recent research indicates that a massive exposition to the vitamin could be a double-edged sword. In this study, the capacity of different caped mesoporous silica particles (i.e. Hollow Silica Shells, MCM-41, SBA-15 and UVM-7) to dose FA during its passage through the gastrointestinal tract has been evaluated. Results confirmed that the four capped materials were capable to hinder the delivery of FA at low pH (i.e. stomach) as well as able to deliver great amounts of the vitamin at neutral pH (i.e. intestine). Nevertheless, the encapsulation efficiency and the deliver kinetics differed among supports. While supports with large p…

OptimizationVitaminPorous silica supportsSmart deliveryINGENIERIA DE LA CONSTRUCCIONFolic acidTECNOLOGIA DE ALIMENTOSSilicon dioxideKinetics02 engineering and technology010402 general chemistryElectron Microscopy Service of the UPV01 natural sciencesAnalytical Chemistrychemistry.chemical_compoundQUIMICA ORGANICAFolic AcidNeutral phPorosityNutritionChemistryQUIMICA INORGANICAGeneral MedicineMesoporous silica021001 nanoscience & nanotechnologySilicon Dioxide0104 chemical sciencesLarge poreNutrition AssessmentBiochemistryChemical engineeringFolic acid0210 nano-technologyPorosityFood ScienceFood chemistry

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Copolymerization of ethylene with 1‐hexene over metallocene catalyst supported on complex of magnesium chloride with tetrahydrofuran

2004

The study of ethylene/1-hexene copolymerization with the zirconocene catalyst, bis(cyclopentadienyl)zirconium dichloride (Cp 2 ZrCl 2 )/methylaluminoxane (MAO), anchored on a MgCl 2 (THF) 2 support was carried out. The influence of 1-hexene concentration in the feed on catalyst productivity and comonomer reactivity as well as other properties was investigated. Additionally, the effect of support modification by the organoaluminum compounds [(MAO, trimethylaluminum (AlMe 3 ), or diethylaluminum chloride (Et 2 AlCl)] on the behavior of the MgCl 2 (THF) 2 /Cp 2 ZrCl/MAO catalyst in the copolymerization process and on the properties of the copolymers was explored. Immobilization of the Cp 2 ZrC…

Polymers and PlasticssupportsOrganic Chemistrymetallocene catalystsMethylaluminoxaneHomogeneous catalysisethylene/1‐hexene copolymersmagnesium supportPost-metallocene catalystzirconocene catalystCatalysischemistry.chemical_compoundcopolymerizationchemistryCyclopentadienyl complexHexenePolymer chemistryMaterials ChemistryMetalloceneTetrahydrofuranJournal of Polymer Science. Part A : Polymer Chemistry

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Supported iridium catalysts for the total oxidation of short chain alkanes and their mixtures: Influence of the support

2021

SupportsGeneral Chemical EngineeringTotal oxidationchemistry.chemical_element02 engineering and technologyIridium oxide010402 general chemistryIridium01 natural sciencesIndustrial and Manufacturing EngineeringCatalysislaw.inventionsymbols.namesakeAdsorptionX-ray photoelectron spectroscopylawAlkanesEnvironmental ChemistryCalcinationIridiumVOCsGeneral Chemistry021001 nanoscience & nanotechnology0104 chemical scienceschemistryChemical engineeringsymbols0210 nano-technologyRaman spectroscopy

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Non-Linear Hysteretic Instability in Rotating Machinery

2013

The destabilizing influence of the shaft hysteresis on the supercritical whirl of rotating machines can be efficiently counterbalanced by proper external dissipative sources in the supports and/or anisotropic suspension systems. The hysteretic effect may be treated either by dry or viscous models obtaining different but somehow similar results in the hypothesis of small dissipation levels. Thus the linear viscous assumption is often accepted as a crude approximation for a straightforward analysis of the whirling instability. Nevertheless the internal friction should be regarded most likely as non-linear and could be approximated for example by Coulombian models taking thus into account also the releasing effect of some shrink-fit coupling present in the mechanical assembly.

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(Co)polymerisation Behaviour of Supported Metallocene Catalysts: Carrier Effect

2006

The polymerisation and copolymerisation of ethylene with 1-hexene over metallocene catalysts L 2 ZrCl 2 / MAO (L = Cp, n-BuCp, t-BuCp, i-PrCp, Me 5 Cp) supported on different types of carriers (MgCl 2 (MeOH) 6 or silica with CH 3 surface groups obtained in the sol-gel process) were studied. It was demonstrated that both the metallocene structure and the type of inorganic support affected catalyst activity and polymer properties such as melting point, molecular weight and molecular weight distribution. The metallocene structure also determined comonomer incorporation, both for homogeneous and supported catalytic systems. When a catalyst is anchored on a support, it becomes less effective at …

chemistry.chemical_classificationsupportsPolymers and PlasticsComonomermetallocene catalystsOrganic ChemistryPolymerPolyethyleneCondensed Matter PhysicsCatalysischemistry.chemical_compoundchemistryPolymerizationPolymer chemistryopolymerizationMaterials ChemistryCopolymerMolar mass distributionstructurePhysical and Theoretical ChemistryCrystafSSAMetalloceneMacromolecular Chemistry and Physics

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La circulation et l'usage des supports enregistrés dans les musiques populaires en Ile de France

2007

Ce rapport est consacré à la façon dont les jeunes musicien-n-e-s apprennent et pratiquent les musiques populaires et plus particulièrement au rôle des supports enregistrés et des machines de reproduction sonore. Il est divisé en deux parties.D'abord l'exposé préliminaire des prémisses historiques et sociologiques qui ont servi de socle à cette recherche (1. Les instructeurs non-humains)La deuxième partie rend compte d'une enquête de terrain menée en Ile de France et, de façon plus limitée, dans l'agglomération nantaise en 2006 et 2007 (2. L'enquête en Ile de France)

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