Search results for "SELE"

showing 10 items of 4721 documents

Enantioselective Friedel-Crafts reaction of hydroxyarenes with nitroenynes to access chiral heterocycles via sequential catalysis

2021

Naphthols, hydroxyindoles and an activated phenol are reacted with differently substituted (E)-nitrobut-1-en-3-ynes using the commercially available Rawal's chiral squaramide. The corresponding β-nitroalkynes were obtained with good yields and excellent enantioselectivities. Moreover, dihydronaphthofurans can be accessed via silver catalysed cyclization in a tandem one-pot procedure, with high preservation of the optical purity.

TandemOrganic ChemistryEnantioselective synthesisSquaramideBiochemistryCatalysischemistry.chemical_compoundchemistryCatàlisiPhenolOrganic chemistryPhysical and Theoretical ChemistryEnantiomeric excessFriedel–Crafts reactionQuímica orgànica
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Syntheses of dopaminergic 1-cyclohexylmethyl-7,8-dioxygenated tetrahydroisoquinolines by selective heterogeneous tandem hydrogenation

2002

Abstract We describe the preparation in a ‘one-pot’ sequence 1-cyclohexylmethyl 7,8-dioxygenated tetrahydroisoquinoline, substituted and unsubstituted in the C ring by application of the Photo–Fries transposition, followed by a tandem reduction–cyclization and further reduction. Indeed, we have accomplished for the first time regioselective hydrogenation of the benzylic ring of the tetrahydroisoquinoline systems. All 1-cyclohexylmethyl THIQ synthesized were able to displace D2 dopamine receptor from its specific binding site in rat striatal membranes, while the N-methylated derivatives showed also affinity for D1 dopamine receptors.

TandemTetrahydroisoquinolineStereochemistryOrganic ChemistryDopaminergicRegioselectivityRing (chemistry)Biochemistrychemistry.chemical_compoundchemistryDopamine receptorTHIQDrug DiscoverymedicineBinding sitemedicine.drugTetrahedron
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Predictors of early scaffold thrombosis: results from the multicenter prospective German-Austrian ABSORB RegIstRy.

2018

BACKGROUND In randomized clinical trials, the risk of thrombotic events with the absorb bioresorbable vascular scaffold (BVS) was significantly higher than with metallic drug-eluting stents. We evaluated predictors of scaffold thrombosis in the large-scale, multicenter German-Austrian ABSORB RegIstRy. METHODS AND RESULTS 3178 patients with treatment of 4252 lesions using 5020 scaffolds were included. Follow-up rate at 6 months was 97.4%. Forty-five (1.42%) patients experienced definite/probable scaffold thrombosis during follow-up. Multiple regression analysis showed implantation of absorb BVS in bifurcation lesions [odds ratio (OR): 4.43; 95% confidence interval (CI): 1.69-11.59; P=0.0024]…

Target lesionMalemedicine.medical_specialtyTime Factorsmedicine.medical_treatmentClinical Decision-MakingCoronary Artery Disease030204 cardiovascular system & hematologyRevascularizationRisk Assessment03 medical and health sciences0302 clinical medicinePercutaneous Coronary InterventionRisk FactorsGermanyAbsorbable ImplantsMedicineHumans030212 general & internal medicineMyocardial infarctionProspective StudiesRegistriesAgedbusiness.industryIncidence (epidemiology)Coronary ThrombosisPatient SelectionGeneral MedicineOdds ratioMiddle AgedDebulkingmedicine.diseaseThrombosisConfidence intervalSurgeryTreatment OutcomeAustriaFemaleCardiology and Cardiovascular MedicinebusinessCoronary artery disease
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Glycerol selective oxidation to lactic acid over AuPt nanoparticles; Enhancing reaction selectivity and understanding by support modification

2020

2 Schemes, 3 Tables, 5 Figures.

Tartronic acidGlycerolDehydration010405 organic chemistryChemistryOrganic ChemistryPrimary alcohol010402 general chemistry01 natural sciencesCatalysis0104 chemical sciencesLactic acidCatalysisInorganic ChemistryReaction ratechemistry.chemical_compoundChemical engineeringAerobic oxidationLewis acids and basesNanocastingLactic AcidPhysical and Theoretical ChemistrySelectivityMesoporous material
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Empirical Autotuning of Two-level Parallel Linear Algebra Routines on Large cc-NUMA Systems

2012

In large cc-NUMA systems the efficient use of the different levels of the memory hierarchy is not an easy task, and the performance of multithreading implementations of the libraries decreases when the number of cores used increases, so producing an important lost of efficiency. To alleviate this problem, routines with multilevel parallelism can be developed by combining OpenMP and BLAS parallelism. In that way, higher performance can be achieved, but it is necessary to develop some autotuning technique for the appropriate selection of the number of threads to use at each level. The selection can be made through theoretical models of the execution time or some installation methodology. This…

Task (computing)Selection (relational algebra)Memory hierarchyComputer scienceMultithreadingLinear algebraParallelism (grammar)Parallel computingTemporal multithreadingMatrix multiplication2012 IEEE 10th International Symposium on Parallel and Distributed Processing with Applications
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Seven Shades of Grey: A Follow-Up Study on the Molecular Basis of Coat Colour in Indicine Grey Cattle Using Genome-Wide SNP Data

2022

Shades of grey and brown are a dominant component in mammal coat colours, representing a fundamental trait involved in a great number of processes including cryptism, sexual selection and signalling. The genetic mechanisms of the grey colouration in mammals are very complex and controlled by hundreds of genes whose effects and interactions are still largely unclear. In this study, we adopted a robust multi-cohort Fst outlier approach based on pairwise contrasts between seven grey indicine cattle breeds and both taurine and indicine non-grey cattle breeds in order to find genomic regions potentially related to the grey colouration. On the basis of three main drawn settings, built in order to…

Taurinecoat colour; cattle; <i>Bos taurus indicus</i>; selection signatures; F<sub>st</sub>selection signatureColorPolymorphism Single NucleotideSettore AGR/17 - Zootecnica Generale E Miglioramento GeneticoGeneticsSingle Nucleotide PolymorphismAnimalsCattleBos taurus indicuFstAnimal FurGenetics (clinical)Phylogenycoat colourFollow-Up Studies
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Synthesis of new fluorinated Tebufenpyrad analogs with acaricidal activity through regioselective pyrazole formation.

2008

In previous studies, our group has shown that the use of fluorinated alcohols such as trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP) as solvents dramatically increases the regioselectivity in the pyrazole formation from 1,3-diketone with methylhydrazine. We have now applied this synthetic method to the preparation of new fluorinated pyrazoles, which have then been used as synthetic intermediates in the preparation of fluorinated analogs of Tebufenpyrad, a commercial acaricide. These compounds display a strong acaricidal activity that is either comparable to or better than that of the commercial compound.

TebufenpyradDiketoneMethylhydrazineHalogenationChemistryOrganic ChemistryHalogenationRegioselectivityPyrazoleChemical synthesisSolventchemistry.chemical_compoundOrganic chemistryAnimalsPyrazolesPesticidesAcaridaeThe Journal of organic chemistry
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Extraction of Antioxidant Compounds and Pigments from Spirulina (Arthrospira platensis) Assisted by Pulsed Electric Fields and the Binary Mixture of …

2021

The application of pulsed electric fields (PEF) is an innovative extraction technology promoting cell membrane electroporation, thus allowing for an efficient recovery, from an energy point of view, of antioxidant compounds (chlorophylls, carotenoids, total phenolic compounds, etc.) from microalgae. Due to its selectivity and high extraction yield, the effects of PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction at different times (5–180 min) and with different solvents (ethanol (EtOH)/H2O, 50:50, v/v

TechnologyAntioxidantQH301-705.5QC1-999pigmentsmedicine.medical_treatmentgreen extractionchemistry.chemical_compoundPigmentmedicineGeneral Materials ScienceBiology (General)QD1-999InstrumentationCarotenoidFluid Flow and Transfer Processeschemistry.chemical_classificationChromatographyEthanolDimethyl sulfoxideTPhysicsmicroalgaeProcess Chemistry and TechnologyExtraction (chemistry)General EngineeringEngineering (General). Civil engineering (General)Computer Science ApplicationsChemistryantioxidantspulsed electric fieldschemistryYield (chemistry)visual_artvisual_art.visual_art_mediumTA1-2040SelectivityApplied Sciences
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Endoscopy at Bedside in Isolated Patients with Severe COVID-19: Our Approach during the Pandemic

2021

The COVID-19 pandemic changed the management of emergency medicine and those complications that needed interventional procedures, such as endoscopy or other radiological procedures. At the beginning of the outbreak, there were no exploitable recommendations regarding the proper policy to apply for limiting the virus spread during endoscopy. Between the first and the second wave, the approach regarding interventional procedures changed, due to higher awareness and newly defined protocols, even if different among the health centers. Patients with severe COVID-19 may develop major gastrointestinal complications or require nutritional support, so interventional procedures are required at bedsid…

TechnologyCoronavirus disease 2019 (COVID-19)QH301-705.5QC1-999gas exchangesGastrointestinal complicationsPandemicMedicineGeneral Materials ScienceinfectionsendoscopyBiology (General)QD1-999InstrumentationFluid Flow and Transfer Processeseducation in ECMOmedicine.diagnostic_testbusiness.industryECMO transportationTPhysicsProcess Chemistry and TechnologyGeneral EngineeringLimitingEngineering (General). Civil engineering (General)medicine.diseaseComputer Science ApplicationsEndoscopyChemistryRadiological weaponMedical emergencyTA1-2040businesspatient selectionApplied Sciences
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Influence of preparation conditions on the catalytic performance of mo/h-zsm-5 for methane dehydroaromatization

2021

[EN] Methane, the main component of natural gas, is an interesting source of chemicals and clean liquid fuels, and a promising alternative raw material to oil. Among the possible direct routes for methane conversion, its aromatization under non-oxidative conditions has received increasing attention, despite the low conversions obtained due to thermodynamic limitations, because of its high selectivity to benzene. Mo/H-ZSM-5, the first bifunctional zeolite-catalyst proposed for this reaction, is still considered as one of the most adequate and has been widely studied. Although the mono- or bifunctional nature of the MDA mechanism is still under debate, it is generally accepted that the Mo spe…

TechnologyQH301-705.5QC1-999Inorganic chemistryCatalysts preparation010402 general chemistry01 natural sciencesMethaneCatalysischemistry.chemical_compoundMo/ZSM-5General Materials ScienceBiology (General)Methane aromatizationZeoliteBifunctionalBenzeneQD1-999InstrumentationFluid Flow and Transfer Processes010405 organic chemistryTPhysicsProcess Chemistry and TechnologyGeneral EngineeringAromatizationCatalyst activationEngineering (General). Civil engineering (General)0104 chemical sciencesComputer Science ApplicationsChemistrychemistryZeolitesTA1-2040ZSM-5Selectivity
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