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showing 10 items of 2851 documents

Asymmetric synthesis of 3,3′-pyrrolidinyl-dispirooxindoles via a one-pot organocatalytic Mannich/deprotection/aza-Michael sequence

2016

Chemical communications 52, 2249-2252 (2016). doi:10.1039/C5CC10057G

3'-pyrrolidinyl-spirooxindole3010405 organic chemistryChemistryMannich/deprotection/aza-Michael sequenceMetals and AlloysEnantioselective synthesisSequence (biology)General Chemistrychemistry010402 general chemistry54001 natural sciencesCombinatorial chemistryCatalysis0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCatalysisStereocenterddc:540Materials ChemistryCeramics and CompositesStereoselectivityta116
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Green Composites Based on PLA and Agricultural or Marine Waste Prepared by FDM

2021

Three dimensional-printability of green composites is recently growing in importance and interest, especially in the view of feasibility to valorize agricultural and marine waste to attain green fillers capable of reducing bioplastic costs, without compromising their processability and performance from an environmental and mechanical standpoint. In this work, two lignocellulosic fillers, obtained from Opuntia ficus indica and Posidonia oceanica, were added to PLA and processed by FDM. Among the 3D printed biocomposites investigated, slight differences could be found in terms of PLA molecular weight and filler aspect ratio. It was shown that it is possible to replace up to 20% of bioplastic …

3D printing Additive manufacturing Aspect ratio Biocomposites Degradation Mechanical properties Opuntia ficus indica Polylactic acid Posidonia oceanica Water contact angle3d printed<i>Opuntia ficus indica</i>Materials sciencePolymers and PlasticsOpuntia ficusOrganic chemistry<i>Posidonia oceanica</i>mechanical propertiesengineering.materialBioplasticArticlechemistry.chemical_compoundQD241-441Polylactic acidFiller (materials)Composite materialpolylactic acidOpuntia ficus indicadegradationbiocompositeswater contact anglePosidonia oceanica3D printingGeneral ChemistryBiodegradationSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialichemistryengineeringDegradation (geology)aspect ratioadditive manufacturingPolymers
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Investigation of charge ratio variation in mRNA – DEAE-dextran polyplex delivery systems

2019

Biomaterials 192, 612 - 620 (2019). doi:10.1016/j.biomaterials.2018.10.020

570Static ElectricityBiophysicsBioengineering02 engineering and technologyGene deliveryBiomaterials03 medical and health scienceschemistry.chemical_compoundDrug Delivery SystemsX-Ray DiffractionDynamic light scatteringddc:570Scattering Small AngleHumansRNA MessengerParticle Size030304 developmental biology0303 health sciencesMessenger RNAHeparinSmall-angle X-ray scatteringDEAE-DextranBiological activityDendritic CellsTransfection021001 nanoscience & nanotechnologySmall-angle neutron scatteringDextranchemistryMechanics of MaterialsCeramics and CompositesBiophysics0210 nano-technology
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Exploration of the Activation Mechanism of the Epigenetic Regulator MLL3: A QM/MM Study

2021

The mixed lineage leukemia 3 or MLL3 is the enzyme in charge of the writing of an epigenetic mark through the methylation of lysine 4 from the N-terminal domain of histone 3 and its deregulation has been related to several cancer lines. An interesting feature of this enzyme comes from its regulation mechanism, which involves its binding to an activating dimer before it can be catalytically functional. Once the trimer is formed, the reaction mechanism proceeds through the deprotonation of the lysine followed by the methyl-transfer reaction. Here we present a detailed exploration of the activation mechanism through a QM/MM approach focusing on both steps of the reaction, aiming to provide new…

570StereochemistryLysineTrimerMolecular Dynamics Simulation01 natural sciencesBiochemistryMicrobiologyenzyme catalysisDFTArticleEpigenesis GeneticEnzyme catalysisQM/MM03 medical and health sciencesResidue (chemistry)Deprotonation0103 physical sciencesprotein regulationHumanscancerCàncerMolecular Biology030304 developmental biology0303 health sciencesBinding Sites010304 chemical physicsbiologyChemistryLysineNuclear ProteinsMethylation540QR1-502DNA-Binding ProteinsHistonebiology.proteinTyrosinemethyltransferaseProtein MultimerizationProtonsProteïnesTranscription Factors
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A Multilayered Plate Theory with Transverse Shear and Normal Warping Functions

2016

A multilayered plate theory which takes into account transverse shear and normal stretching is presented. The theory is based on a seven-unknowns kinematic field with five warping functions. Four warping functions are related to the transverse shear behaviour, the fifth is related to the normal stretching. The warping functions are issued from exact three-dimensional solutions. They are related to the variations of transverse shear and normal stresses computed at specific points for a simply supported bending problem. Reddy, Cho-Parmerter and (a modified version of) Beakou-Touratier theories have been retained for comparisons. Extended versions of these theories, able to manage the normal s…

74K20 (Primary) 74Q99 (Secondary)Materials science[SPI] Engineering Sciences [physics][ SPI.MAT ] Engineering Sciences [physics]/MaterialsFOS: Physical sciencesPhysics - Classical PhysicsStatics02 engineering and technologySandwich panelBendingOrthotropic materialVibrationShellsdeformation-theory[SPI]Engineering Sciences [physics]Laminated composite0203 mechanical engineeringComposite plateComposite plates[ SPI ] Engineering Sciences [physics]Image warpingLaminateComputingMilieux_MISCELLANEOUSCivil and Structural EngineeringHigher-order theorybusiness.industryMathematical analysisIsotropyClassical Physics (physics.class-ph)Warping functionBending of platesStructural engineering021001 nanoscience & nanotechnology020303 mechanical engineering & transportsFormulationPlate theoryCeramics and CompositesPlate theorySandwich0210 nano-technologybusinessNormal stretchingFinite-elements
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Thermomineral waters of Greece: geochemical characterization

2020

75 °C). In terms of pH most results vary from 5.5 to 823 °C) ii) warm (23 40 °C) iii) thermal (40 75 °C) and iv) hyperthermal (&gtfew springs show either very low pH (&lt10) proposing serpentinization processes. Regarding TDS concentrations collected waters can be subdivided into low salinity (up to 1.5 g/L) brackish (up to 20 g/L) and saline (up to 43 g/L). The medium high salinities can be justified by mixing with sea water and/or strong waterrock interaction processes. Isotope composition of O and H ranges from 12.7 to +2.7 ‰ SMOW and from 91 to +12 ‰ SMOW respectively and is generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Only few water samples show a positive shift for δ18O possibly related to high temperature waterrock interaction processes. Carbon dioxide (18 997000 μmol/mol) or N2 (1100 989000 μmol/mol) or CH4 (&ltMany geothermal areas of Greece are located in regions affected by Miocene or Quaternary volcanism and in continental basins characterised by elevated heat flow. Moreover the majority of them is found along the coast as well as in islands of the Aegean Sea and thus thermal water is often brackish to saline due to marine intrusion into costal aquifer. In the present study almost 300 thermal and cold mineral water samples were collected along the Hellenic territory with their physicochemical parameters (temperature pH electrical conductivity and Eh) and the amount of bicarbonates (titration with 0.1N HCl) being determined in situ. Additionally gases found either in free or dissolved phase were sampled. Both water and gas samples were analysed at the INGVPa laboratories for major ions (Ion Chromatography) silica (Inductively Coupled Plasma Optical Emission Spectrometry) chemical composition of free and dissolved gases (Gas Chromatography) water isotopes (O and H) and carbon and helium isotopes of free and dissolved gases (Mass Spectrometry). The temperature of the investigated waters ranges from 6.5 to 98°C pH from 1.96 to 11.98 whilst Total Dissolved Solids (TDS) from 0.06 to 43 g/L. Based on the temperature parameter waters can be divided into four groups: i) cold (&lt0.5 913000 μmol/mol) are the prevailing gas species found in the studied sites. The δ13CCO2 values ranged from 20.1 to +8.5 ‰ whilst the isotope ratio of He from 0.21 to 6.71 R/RA.4) suggesting interaction with H2Srich gases or very high pH values (&gtSettore GEO/08 - Geochimica E Vulcanologia
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Constitutive and regulated α-secretase cleavage of Alzheimer’s amyloid precursor protein by a disintegrin metalloprotease

1999

Amyloid β peptide (Aβ), the principal proteinaceous component of amyloid plaques in brains of Alzheimer’s disease patients, is derived by proteolytic cleavage of the amyloid precursor protein (APP). Proteolytic cleavage of APP by a putative α-secretase within the Aβ sequence precludes the formation of the amyloidogenic peptides and leads to the release of soluble APPsα into the medium. By overexpression ofa disintegrinandmetalloprotease (ADAM), classified as ADAM 10, in HEK 293 cells, basal and protein kinase C-stimulated α-secretase activity was increased severalfold. The proteolytically activated form of ADAM 10 was localized by cell surface biotinylation in the plasma membrane, but the m…

ADAM10Molecular Sequence DataBiologyKidneyTransfectionCell LineSubstrate SpecificityADAM10 ProteinAmyloid beta-Protein PrecursorEndopeptidasesAmyloid precursor proteinAnimalsAspartic Acid EndopeptidasesHumansPoint MutationADAM17 ProteinAmino Acid SequenceCloning MolecularProtein kinase AProtein Kinase CSecretory pathwayBinding SitesMultidisciplinaryHEK 293 cellsP3 peptideMembrane ProteinsMetalloendopeptidasesBiological SciencesPeptide FragmentsRecombinant Proteinscarbohydrates (lipids)ADAM ProteinsKineticsZincAlpha secretaseBiochemistryMutagenesis Site-Directedbiology.proteinCattleAmyloid Precursor Protein SecretasesProceedings of the National Academy of Sciences
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How and Where are Drugs Absorbed?

2007

A drug must interact with its receptors at their action sites or therapeutic target to exert its pharmacological or toxic effects. Therefore, the absorption of drug is an essential step which determines pharmacologic effects of drug. This article focuses on the biological barriers that the drug must cross in order to enter the body, drug absorption mechanisms, and influence of physiological characteristics of the administration route on absorption rate and extent. Keywords: drugs; absorption mechanisms; administration routes; passive diffusion; endocytosis

Absorption (pharmacology)DrugAbsorption rateChemistrymedia_common.quotation_subjectPharmacologic effectsReceptor-mediated endocytosisPharmacologyEndocytosisAction sitesmedia_common
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The effects of water absorption and salt fog exposure on agglomerated cork compressive response

2022

The replacement of synthetic foams with agglomerated cork in sandwich composites can meet the increasing environmental concerns. Its peculiar morphology and chemical composition lead to outstanding dimensional recovery that endorsed a broad investigation of its compressive behavior. The knowledge of neat material response is fundamental to obtain a reliable design dataset, but it is necessary to consider all the environmental factors (water, moisture and sunlight) that significantly modify material mechanical properties. In view of this, the present work investigates the effect of distilled and seawater absorption and salt fog exposure on the compressive behavior of two agglomerated corks w…

Absorption of waterMaterials scienceAgglomerated corkMechanical propertiesCorkengineering.materialThermal diffusivitywater absorptionGeneral Materials ScienceComposite materialSandwich structuresChemical compositionSalt fog exposurePolymer compositesMaterialesMoistureForestryagglomerated corkagglomerated cork; water absorption; salt fog exposureCompressive strengthSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialiDistilled waterengineeringsalt fog cork aging compressive responseWater absorptionSeawatersalt fog exposure
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Durability of Biodegradable Polymer Nanocomposites

2021

Biodegradable polymers (BP) are often regarded as the materials of the future, which address the rising environmental concerns. The advancement of biorefineries and sustainable technologies has yielded various BP with excellent properties comparable to commodity plastics. Water resistance, high dimensional stability, processability and excellent physicochemical properties limit the reviewed materials to biodegradable polyesters and modified compositions of starch and cellulose, both known for their abundance and relatively low price. The addition of different nanofillers and preparation of polymer nanocomposites can effectively improve BP with controlled functional properties and change the…

Absorption of waterNanocompositeMaterials sciencePolymers and PlasticsPolymer nanocompositeOrganic chemistryGeneral ChemistryReviewBiodegradationBiodegradable polymerDurabilitybiodegradationcreepPolyestermodellingCommodity plasticsQD241-441biodegradable polymersenvironmental ageingnanocompositesdurabilityComposite materialPolymers
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