Search results for "SAMPLE"

showing 10 items of 2270 documents

Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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Some models of inductive syntactical synthesis from sample computations

2005

The paper is a survey of several models of inductive program synthesis from sample computations. Synthesis tools are basically syntactical: the synthesis is based on the detection of "regular" fragments related with "shuffled" arithmetical progressions. Input sample computations are supposed to be "representative": they have to "reflect" all loops occurring in the target program. Programs are synthesized in nontraditional form of "generalized" regular expressions having Cleene stars and unions for loops and CASE-like operators. However, if input samples are somehow "annotated" (we consider two different approaches), then loops can be synthesized in more traditional WHILE-form, where loop co…

Theoretical computer scienceLOOP (programming language)ComputationSample (material)Arithmetic functionRegular expressionProgram synthesisMathematics
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On the classification of large residential buildings stocks by sample typologies for energy planning purposes

2014

Local and central administrations are often called to properly allocate economic resources intended for the territorial energy planning, on the basis of the performances achieved by implementing energy conservation measures. Particularly in the residential sector, that represents one of the most relevant sector for the energy demand, effective and reliable evaluation tools are required for this aim. Unfortunately, building stocks are characterized by a very large number of buildings that are referred to different construction periods and are equipped with a variety of appliances and tools, other than with different heating and cooling systems. This means that the whole energy consumption of…

Thermal consumptionEngineeringOfficial statisticsSettore ING-IND/11 - Fisica Tecnica Ambientalebusiness.industryMechanical EngineeringLarge numbersBuilding and ConstructionEnergy consumptionManagement Monitoring Policy and LawEnvironmental economicsEnergy planningCivil engineeringElectric applianceEnergy accountingEnergy policyEnergy conservationGeneral EnergySample typologieBuildings stockbusinessEnergy policyStock (geology)Applied Energy
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Influence of sample pan on the thermal behaviour of KSCN measured with TG

2003

Abstract In this study, the influence of the sample pan on the thermal behaviour of potassium thiocyanate (KSCN) was investigated. The measurements were performed with thermogravimetry (TG) and the two sample pans used were a platinum pan and a ceramic crucible. The samples were heated to 400–950 °C and the thermal products were identified by powder diffraction. The thermal behaviour of KSCN was found to be dependent on the sample pan used. With the platinum sample pan KSCN reacted in the first step into a mixture of K 2 SO 4 and potassium tetracyanoplatinate (K 2 Pt(CN) 4 ). In the second step, the mixture reacted further to pure K 2 SO 4 . In the ceramic sample crucible, however, the reac…

ThiocyanateAnalytical chemistrychemistry.chemical_elementCondensed Matter PhysicsAlkali metalRubidiumThermogravimetrychemistry.chemical_compoundchemistryPotassium thiocyanateSample preparationPhysical and Theoretical ChemistryPlatinumThermal analysisInstrumentationThermochimica Acta
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(Supplementary Table 1) 230Th/U results for stalagmite Cuba Grande (CG) from Pinar del Rio

2010

We present 22 U-series ages for a stalagmite from north-western Cuba based on multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and thermal ionisation mass spectrometry (TIMS). Our results reveal that the stalagmite continuously grew within the last ~1400a. Low uranium content of the sample and thus, extremely low 230Th concentrations limit the precision and accuracy of 230Th/U-dating by TIMS. Samples measured by MC-ICPMS show a high variability of 232Th content along the growth axis with some sections significantly affected by initial 230Th from a detrital phase. An a-priori bulk earth ratio for (238U/232Th) cannot be used to accurately account for this initial 230Th.…

Thorium 230 Uranium 238 ratioUranium-234 standard deviationIntegrierte Analyse zwischeneiszeitlicher Klimadynamik INTERDYNAMIKUranium 238Thorium 230 Uranium 238 activity ratioUranium-238Thorium-230/Uranium-238 activity ratio standard deviationAge commentUranium 234Integrierte Analyse zwischeneiszeitlicher Klimadynamik (INTERDYNAMIK)commentAge dateddateddated standard deviationAgeAge dated standard deviationThorium-232 standard deviationThorium-230/Uranium-238 ratioMulti collector inductively coupled plasma mass spectrometer MC ICP MSThorium-230/Thorium-232 activity ratioThorium 232Uranium-238 standard deviationSpeleothem sampleThorium 230 Thorium 232 activity ratioUranium-234/Uranium-238 activity ratioUranium 234 Uranium 238 activity ratioThorium-232DISTANCEEarth System ResearchMulti-collector inductively coupled plasma mass spectrometer (MC-ICP-MS)standard deviationThorium-230/Thorium-232 activity ratio standard deviation
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Performance of EU-TIRADS in malignancy risk stratification of thyroid nodules. A meta-analysis

2020

Objective: Several thyroid imaging reporting and data systems (TIRADS) have been proposed to stratify the malignancy risk of thyroid nodule by ultrasound. The TIRADS by the European Thyroid Association, namely EU-TIRADS, was the last one to be published. Design: We conducted a meta-analysis to assess the prevalence of malignancy in each EU-TIRADS class and the performance of EU-TIRADS class 5 vs 2, 3 and 4 in detecting malignant lesions. Methods: Four databases were searched until December 2019. Original articles reporting the performance of EU-TIRADS and adopting histology as reference standard were included. The number of malignant nodules in each class and the number of nodules classifi…

Thyroid nodulesReproducibility of resultsmedicine.medical_specialtyEndocrinology Diabetes and Metabolism030209 endocrinology & metabolismReproducibility of results; sensitivity and specificity; thyroid nodule; ultrasonography; ultrasoundMalignancyGastroenterologyRisk Assessment03 medical and health sciences0302 clinical medicineEndocrinologyInternal medicinemedicineHumansRetrospective Studiesbusiness.industryultrasoundThyroidNodule (medicine)Retrospective cohort studyGeneral Medicineultrasonographymedicine.diseaseEndocrinologymedicine.anatomical_structureSample size determinationsensitivity and specificity030220 oncology & carcinogenesisMeta-analysisRisk stratificationthyroid nodulemedicine.symptombusiness
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Detectability of cannabinoids in the serum samples of cannabis users: Indicators of recent cannabis use? A follow‐up study

2021

Forensic toxicologists are frequently required to predict the time of last cannabis consumption. Several studies suggested the utility of minor cannabinoids as indicators of recent cannabis use. Because several factors influence blood cannabinoid concentrations, the interpretation of serum cannabinoid concentrations remains challenging. To assess the informative value of serum cannabinoid levels in cannabis users (in total N = 117 patients, including 56 patients who stated an exact time of last cannabis use within 24 h before blood sampling), the detectability of cannabinoids, namely delta-9-tetrahydrocannabinol (delta-9-THC), 11-hydroxy-delta-9-THC, 11-nor-9-carboxy-delta-9-THC, cannabichr…

Time FactorsCannabigerolmedicine.medical_treatmentPharmaceutical SciencePhysiologyTetrahydrocannabivarin01 natural sciencesAnalytical Chemistry03 medical and health scienceschemistry.chemical_compoundCannabichromene0302 clinical medicineTandem Mass SpectrometrymedicineHumansEnvironmental Chemistry030216 legal & forensic medicineSpectroscopybiologyCannabinoidsbusiness.industry010401 analytical chemistrybiology.organism_classification0104 chemical sciencesSubstance Abuse DetectionchemistryTetrahydrocannabinolic acidCannabinolMarijuana UseCannabinoidSample collectionCannabisbusinessChromatography LiquidFollow-Up Studiesmedicine.drugDrug Testing and Analysis
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Optimization of a matrix solid-phase dispersion method for the analysis of pesticide residues in vegetables

1996

A multiresidue method based on matrix solid-phase dispersion (MSPD) is studied to determine chlorfenvinfos, chlorpyrifos, fenarimol, iprodione, procimydone, propiconazole, tetradifon, triadimefon and vinclozolin in artichokes, green beans, lettuces and tomatoes. Alumina, silica and Florisil were assessed as extracting phases, and the extracts from Florisil were the cleanest. To facilitate manual extraction, sand was added to the sample together with the dispersing phase. Three eluting systems were then studied, and dichloromethane proved to be the best. Further purification can be performed using solid-phase cleanup after diluting extracts with aqueous solutions. Octyl- and octadecyl-silica…

Time FactorsChromatographyChemistryOrganic ChemistryPesticide ResiduesReproducibility of ResultsGeneral MedicineBiochemistryGas Chromatography-Mass SpectrometryAnalytical ChemistryMatrix (chemical analysis)chemistry.chemical_compoundElectron capture detectorVegetablesSelected ion monitoringSample preparationGas chromatographyProcymidoneSolid phase extractionVinclozolinJournal of Chromatography A
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Copper, iron, and zinc contents in human milk during the first three months of lactation: A longitudinal study

2000

The aim of the study has been to analyze the evolution of copper, iron, and zinc contents in human milk, from colostrum to the third postpartum month, following a longitudinal design, under specific conditions of sample collection and to apply an analytical procedure previously optimized to reduce any variation outside physiological lactation. The copper, iron, and zinc concentrations in 144 milk samples from 39 healthy puerpera women, were analyzed in five stages by flame atomic absorption spectrometry, following a standardized protocol. Copper presented a gradual decrease from 0.38 mg/L to 0.19 mg/L by the 90th day; the particular analysis from colostrum to transitional milk manifested th…

Time FactorsIronEndocrinology Diabetes and MetabolismClinical Biochemistrychemistry.chemical_elementZincBiochemistryInorganic ChemistryAnimal scienceFlame atomic absorption spectrometryLactationmedicineHumansLactationLongitudinal StudiesMilk HumanChemistryColostrumSpectrophotometry AtomicBiochemistry (medical)General MedicineCopperZincFirst trimestermedicine.anatomical_structureEnvironmental chemistryIron contentColostrumFemaleSample collectionCopper
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Minimal exposure time of different LED-curing devices

2007

Abstract Objectives The purpose of the study was to investigate the shortest possible exposure time of different LED-curing devices for five different resin composites in a clinically relevant in vitro-model, where a 7 mm distance from the light guide tip to the bottom side of the cavity was compiled. Methods Resin composite samples (Tetric EvoCeram A3, Filtek Supreme XT A3B, Premise A3, CeramX Mono M5, QuiXfil) were filled in three increments of 2 mm thickness each in stainless steel moulds (O = 5 mm, h  = 6 mm, n  = 9). The samples were incrementally exposed to different blue LED-curing devices (Bluephase, Bluephase C8, Bluephase 16i/Ivoclar Vivadent, L.E.Demetron II/sds Kerr, Elipar Free…

Time FactorsMaterials scienceLightSurface PropertiesHardness ratioResin compositeComposite numberLight guideEquipment DesignComposite ResinsHardnessTetric EvoCeramDental MaterialsReference sampleHardnessMechanics of MaterialsMaterials TestingHumansGeneral Materials ScienceComposite materialGeneral DentistryLightingCuring (chemistry)Dental Materials
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