Search results for "COMB"

showing 5 items of 7115 documents

Ortho -Functionalized Aryltetrazines by Direct Palladium-Catalyzed C−H Halogenation: Application to Fast Electrophilic Fluorination Reactions

2016

International audience; A general catalyzed direct C-H functionalization of s-tetrazines is reported. Under mild reaction conditions, N-directed ortho-C-H activation of tetrazines allows the introduction of various functional groups, thus forming carbon-heteroatom bonds: C-X (X=I, Br, Cl) and C-O. Based on this methodology, we developed electrophilic mono- and poly-ortho-fluorination of tetrazines. Microwave irradiation was optimized to afford fluorinated s-aryltetrazines, with satisfactory selectivity, within only ten minutes. This work provides an efficient and practical entry for further accessing highly substituted tetrazine derivatives (iodo, bromo, chloro, fluoro, and acetate precurso…

weak-coordinationbond fluorination412chemistry.chemical_elements-tetrazines010402 general chemistrychemistry01 natural sciences5-tetrazines[ CHIM ] Chemical SciencesCatalysisCatalysiscycloadditionsTetrazinechemistry.chemical_compoundhalogenationfluorineOrganic chemistryMolecule[CHIM]Chemical SciencesmoleculesC-H activationheterocycles010405 organic chemistryElectrophilic fluorinationHalogenationGeneral ChemistrypalladiumCombinatorial chemistry0104 chemical scienceschemistryimaging probesElectrophilecellsfluorescenceSelectivityPalladium
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Flexible and Efficient Computer-Aided Design Tool for Advanced Comb-Line Rectangular Waveguide Filters

2015

A very flexible and efficient computer-aided design (CAD) tool, specifically suited for advanced comb-line rectangular waveguide filters, is presented in this work. The developed software tool, which makes use of a full-wave analysis technique based on the Boundary Integral - Resonant Mode Expansion method, permits to load the considered comb-line resonators with any number of radially symmetrical partial-height metallic posts. The implemented CAD tool also allows for dealing with coupling windows of arbitrary cross-section, thus drastically enhancing the flexibility of the computer-aided design process. The excitation of the analyzed components, which is performed by using generalized coax…

wide-band matricesfull-wave analysis methods04 - Ciencia y tecnología de los ordenadores. Informática. [CDU]68 - Tecnología cibernética y automática [CDU]CAD toolcomb-line rectangular waveguide filters
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Obesity and survival in operable breast cancer patients treated with adjuvant anthracyclines and taxanes according to pathological subtypes: a pooled…

2013

Obesity is an unfavorable prognostic factor in breast cancer (BC) patients regardless of menopausal status and treatment received. However, the association between obesity and survival outcome by pathological subtype requires further clarification. METHODS: We performed a retrospective analysis including 5,683 operable BC patients enrolled in four randomized clinical trials (GEICAM/9906, GEICAM/9805, GEICAM/2003-02, and BCIRG 001) evaluating anthracyclines and taxanes as adjuvant treatments. Our primary aim was to assess the prognostic effect of body mass index (BMI) on disease recurrence, breast cancer mortality (BCM), and overall mortality (OM). A secondary aim was to detect differences o…

Índice de Masa CorporalOncologyReceptor ErbB-2medicine.medical_treatmentObesidad:Analytical Diagnostic and Therapeutic Techniques and Equipment::Investigative Techniques::Epidemiologic Methods::Statistics as Topic::Survival Analysis [Medical Subject Headings]Supervivencia sin EnfermedadBody Mass IndexAntineoplastic Combined Chemotherapy ProtocolsMedicineAnthracyclinesYoung adultMedicine(all)Hazard ratioNeoplasias de la MamaPronósticoFemeninoMiddle AgedPrognosisChemotherapy regimenTreatment OutcomeFemaleTaxoidsMastectomyResearch ArticleAdultmedicine.medical_specialtyAnálisis de Supervivencia:Analytical Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Diagnostic Techniques and Procedures::Physical Examination::Body Constitution::Body Weights and Measures::Body Mass Index [Medical Subject Headings]Breast NeoplasmsDisease-Free SurvivalYoung AdultBreast cancerInternal medicineAdjuvant therapyHumansObesity:Analytical Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Prognosis::Disease-Free Survival [Medical Subject Headings]:Diseases::Neoplasms::Neoplasms by Site::Breast Neoplasms [Medical Subject Headings]AgedGynecologyDose-Response Relationship Drugbusiness.industry:Chemicals and Drugs::Chemical Actions and Uses::Pharmacologic Actions::Therapeutic Uses::Antineoplastic Agents [Medical Subject Headings]Retrospective cohort studyAntineoplásicosmedicine.disease:Diseases::Nutritional and Metabolic Diseases::Nutrition Disorders::Overnutrition::Obesity [Medical Subject Headings]:Check Tags::Female [Medical Subject Headings]Multivariate Analysis:Analytical Diagnostic and Therapeutic Techniques and Equipment::Diagnosis::Prognosis [Medical Subject Headings]Neoplasm Recurrence LocalbusinessBody mass index
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α-Conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors

2003

The Xenopus laevis oocyte expression system was used to determine the activities of alpha-conotoxins EpI and the ribbon isomer of AuIB, on defined nicotinic acetylcholine receptors (nAChRs). In contrast to previous findings on intracardiac ganglion neurones, alpha-EpI showed no significant activity on oocyte-expressed alpha3beta4 and alpha3beta2 nAChRs but blocked the alpha7 nAChR with an IC50 value of 30 nM. A similar IC50 value (103 nM) was obtained on the alpha7/5HT3 chimeric receptor stably expressed in mammalian cells. Ribbon AuIB maintained its selectivity on oocyte-expressed alpha3beta4 receptors but unlike in native cells, where it was 10-fold more potent than native alpha-AuIB, had…

α7 nicotinic acetylcholine receptorα-Conotoxin AuIBRecombinant Fusion ProteinsBiophysicsXenopusNicotinic AntagonistsReceptors NicotinicPharmacologyTransfectionBiochemistrycomplex mixturesSubstrate SpecificityInhibitory Concentration 50Xenopus laevisStructural BiologyGeneticsmedicineAnimalsConotoxinNicotinic AntagonistReceptorMolecular BiologyAcetylcholine receptorbiologyα-Conotoxin EpICell Biologybiology.organism_classificationRatsCell biologyProtein SubunitsNicotinic acetylcholine receptorNicotinic agonistnervous systemIntracardiac gangliaOocytessense organsReceptors Serotonin 5-HT3ConotoxinsAcetylcholineXenopus laevis oocytemedicine.drugFEBS Letters
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Desymmetrization of Prochiral Cyclobutanones via Nitrogen Insertion: A Concise Route to Chiral γ‐Lactams

2021

Abstract Asymmetric access to γ‐lactams is achieved via a cyclobutanone ring expansion using widely available (1S,2R)‐1‐amino‐2‐indanol for chiral induction. Mechanistic analysis of the key N,O‐ketal rearrangement reveals a Curtin–Hammett scenario, which enables a downstream stereoinduction (up to 88:12 dr) and is corroborated by spectroscopic, crystallographic, and computational studies. In combination with an easy deprotection protocol, this operationally simple sequence allows the synthesis of a range of optically pure γ‐lactams, including those bearing all‐carbon quaternary stereocenters. In addition, the formal synthesis of drug molecules baclofen, brivaracetam, and pregabalin further …

γ-lactamsChiral auxiliary010405 organic chemistryChemistryasymmetric synthesisEnantioselective synthesisCyclobutanoneGeneral Chemistry010402 general chemistryRing (chemistry)01 natural sciencesCombinatorial chemistryDesymmetrizationCatalysis0104 chemical sciencesStereocenterdesymmetrizationFormal synthesischemistry.chemical_compoundMoleculecyclobutanoneResearch ArticlesResearch ArticleAsymmetric Synthesis | Hot PaperAngewandte Chemie International Edition
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