Search results for "547"
showing 10 items of 76 documents
Sensitive Assays by Nucleophile-Induced Rearrangement of Photoactivated Diarylethenes.
2018
Upon light-induced isomerization, diarylethenes (DAEs) equipped with reactive aldehyde moieties rearrange selectively in the presence of amines, accompanied by decoloration. In a comprehensive study, the probe structure was optimized with regard to its inherent reactivity in the nucleophile-triggered rearrangement reaction. Detailed structure−reactivity relationships could be derived, in particular with regard to the type of integrated (het)aryl moieties as well as the location of the formyl residue, and the probes’ intrinsic reactivity with primary and secondary amines was optimized. Utilizing an ancillary base, the initially formed rearrangement product can engage in a subsequent catalyti…
Evaluating structural and compositional canopy characteristics to predict the light-demand signature of the forest understorey in mixed, semi-natural…
2020
Questions: Light availability at the forest floor affects many forest ecosystem processes, and is often quantified indirectly through easy-to-measure stand characteristics. We investigated how three such characteristics, basal area, canopy cover and canopy closure, were related to each other in structurally complex mixed forests. We also asked how well they can predict the light-demand signature of the forest understorey (estimated as the mean Ellenberg indicator value for light [“EIVLIGHT”] and the proportion of “forest specialists” [“%FS”] within the plots). Furthermore, we asked whether accounting for the shade-casting ability of individual canopy species could improve predictions of EIV…
Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests
2019
Topsoil conditions in temperate forests are influenced by several soil-forming factors, such as canopy composition (e.g. through litter quality), land-use history, atmospheric deposition, and the parent material. Many studies have evaluated the effects of single factors on physicochemical topsoil conditions, but few have assessed the simultaneous effects of multiple drivers. Here, we evaluate the combined effects of litter quality, land-use history (past land cover as well as past forest management), and atmospheric deposition on several physicochemical topsoil conditions of European temperate deciduous forest soils: bulk density, proportion of exchangeable base cations, carbon/nitrogen-rat…
Sintesis y evaluación biológica de nuevos derivados de tipo imidazolina y etanolamina fluorados
2011
Una de las principales áreas de interés de la química orgánica es la búsqueda de nuevos compuestos con actividad biológica. En este sentido cabe destacar el especial interés que despiertan los compuestos nitrogenados debido a que constituyen una de las familias más numerosas entre las biomoléculas y que están implicados en múltiples procesos a nivel metabólico y estructural. Un ejemplo representativo los constituyen los compuestos de tipo etanolamina, ampliamente estudiados por sus variadas y numerosas aplicaciones. Por una parte han servido como modelo para el diseño de peptidomiméticos derivados de hidroxietilamina, que resultan interesantes como inhibidores de proteasas. Algunos de ellos…
Reacciones de Friedel-Crafts enantioselectivas catalizadas por complejos de metales de transición del grupo (IV) y binol
2010
La reacción de Friedel-Crafts es un poderoso proceso de formación de enlaces carbono-carbono de gran importancia en síntesis orgánica. La aplicación de la versión asimétrica catalítica de esta reacción a la alquilación de arenos ricos en electrones, como indoles o pirroles, puede proporcionar acceso a importantes productos enantioméricamente enriquecidos alquilados y constituyen un tema de actual interés, ya que estos arenos se han identificado como estructuras "privilegiadas" o farmacóforos. Los complejos Zr(IV) y Hf(IV)-BINOL generados in situ han sido evaluados como catalizadores en la alquilación de Friedel-Crafts enantioselectiva de indoles y pirroles con diferentes cetonas α, β-insatu…
Pre-marital and pre-unional financial agreements and their circulation in the context of the new EU regulations 2016/1103 and 2016/1104
2021
Regulations (EU) 2016/1103 and 2016/1104 provide spouses and partners with the possibility to conclude agreements for the organization of their property regime but do not detail their content and structure. Moreover, while the possibility to conclude those agreements even prior to the marriage or the conclusion of a registered partnership is a valuable innovation in comparison with other European Regulations in family matters, some choices made by the European legislator on applicable law will likely be source of inconveniences. Furthermore, as for their recognition and enforcement in the participating Member States ? which will be based on the same rules enacted for decisions, authentic in…
Surgical treatment of choanal atresia with transnasal endoscopic approach with stentless single side-hinged flap technique: 5 year retrospective anal…
2017
Introdução: A atresia de coanas é uma malformação congênita rara da cavidade nasal caracterizada pela obliteração completa da coana posterior. Nos 67% dos casos a atresia coanal é unilateral, acometendo principalmente (71%) a cavidade nasal direita. Diferentemente da forma unilateral, a atresia coanal bilateral é uma condição com risco de vida, frequentemente associada a angústia respiratória com alimentação e cianose intermitente exacerbada pelo choro. O tratamento cirúrgico permanece como a única opção terapêutica. Objetivo: Relatar a nossa experiência no uso de uma abordagem endoscópica transnasal com a técnica de retalho articulado de um lado só sem colocação de stent para o tratamento …
Comparison of Electrocochleography and Video Head Impulse Test findings in Vestibular Migraine and Ménière Disease: A Preliminary Study
2020
OBJECTIVES: To evaluate electrophysiological findings among patients with vestibular migraine (VM) and to compare them with those of patients suffering from definite Ménière disease (MD) without migraine. MATERIALS and METHODS: Twenty-one consecutive patients suffering from VM were enrolled; all subjects were selected according to the criteria proposed by the Bàràny Society for Neuro-otology. Each patient underwent a careful otological and neurotological examination. After completing a questionnaire regarding migraine and vertigo complaints, they were assessed by audiometric testing, video head impulse test (vHIT), and elec-trocochleography (EcochG). Data were compared with those of 21 pati…
Papel prognóstico da margem de ressecção em cirurgia oncológica aberta de laringe: análise de sobrevida de uma coorte de 139 pacientes com carcinoma …
2019
Introduction: The treatment of laryngeal squamous cell carcinoma needs accurate risk stratification, in order to choose the most suitable therapy. The prognostic significance of resection margin is still highly debated, considering the contradictory results obtained in several studies regarding the survival rate of patients with a positive resection margin. Objective: To evaluate the prognostic role of resection margin in terms of survival and risk of recurrence of primary tumour through survival analysis. Methods: Between 2007 and 2014, 139 patients affected by laryngeal squamous cell carcinoma underwent partial or total laryngectomy and were followed for mean of 59.44 ± 28.65 months. Rese…
Reading Disabilities in children with Specific Language Impairment
2019
El presente estudio examinó el rendimiento en lectura de los niños con Trastorno Específico del Lenguaje (TEL). Treinta niños con TEL y 32 niños con desarrollo normal del lenguaje, equilibrados en género, edad cronológica e inteligencia, fueron evaluados mediante el PROLEC-R. Los resultados de los ANOVAs indicaron que ambos grupos difieren en el rendimiento en lectura. Como grupo, los niños con TEL tuvieron significativamente un rendimiento inferior, tanto en la exactitud como en el tiempo de la lectura de palabras y pseudopalabras, por lo que tenían una menos eficacia de lectura. En la misma línea, el rendimiento de los niños con TEL en comprensión literal e inferencial también fue inferio…