Synthesis of 3,5-Disubstituted Isoxazoles and Isoxazolines in Deep Eutectic Solvents

The synthesis of different 3,5-disubstituted isoxazoles and related isoxazolines using choline chloride:urea as deep eutectic solvent (DES) in a one-pot three step reaction has been accomplished successfully. The use of highly nucleophilic functionalized DES did not affect the process where highly electrophilic reagents or intermediates are involved. The presence of DES showed to be essential since the reaction in absence of this media did not proceed. The DES media could be reused up to five times without a detrimental effect on the yield of the reaction. To exemplify the synthetic potential of this methodology, the reaction was scaled up to the gram scale without any noticeable problem. Finally, different isoxazoles were easily transformed into β-aminoenones.This work was supported by the Spanish Ministerio de Economía y Competitividad (MICINN; Grant CTQ2011-24151) and University of Alicante. J.M.P. thanks the MICINN (FPI program) for her fellowship

Point defects on graphene on metals

Understanding the coupling of graphene with its local environment is critical to be able to integrate it in tomorrow's electronic devices. Here we show how the presence of a metallic substrate affects the properties of an atomically tailored graphene layer. We have deliberately introduced single carbon vacancies on a graphene monolayer grown on a Pt(111) surface and investigated its impact in the electronic, structural and magnetic properties of the graphene layer. Our low temperature scanning tunneling microscopy studies, complemented by density functional theory, show the existence of a broad electronic resonance above the Fermi energy associated with the vacancies. Vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in free-standing graphene layers

La investigación en educación musical en la base de datos ERIC

En este artículo se describe un análisis bibliométrico de los artículos de investigación en Educación Musical indexados en la base ERIC y publicados durante el período de 1995 a 2007. Estos artículos constituyen el 54% del total de artículos censados en la base relacionados con la Educación Musical. Como resultado se ofrece un listado con las 10 revistas que contienen más de 20 artículos sobre Educación Musical del total censado; La suma de los artículos publicados por las cuatro principales revistas constituye el 60% del total. Ninguna de las cuatro aparece censada en el JCR Social Sciences. La casi totalidad de los autores de dichos artículos trabajan en solitario y de forma ocasional, sin que parezca que existen grupos de investigación o líneas fuertemente consolidadas.This article describes a bibliometrical analysis of articles on research in Music Education published from 1995 to 2007 and included in ERIC database. These articles represent 54% of all music education articles included in this database. The results show a list with 10 journals which has more than 20 of these articles. The sum of the articles contained in the first four journals is equivalent to 60% of music education articles published from 1995 to 2007. None of these journals are at JCR Social Sciences. Almost all authors of the revised articles usually work alone and occasionally. It seems that there are not research groups or strong consolidated research directions. The most common subjects are: students (attitudes, motivation and effectiveness); teachers; musical composition (activities and music techniques

The emergent role of digital technologies in the context of humanitarian supply chains: a systematic literature review

The role of digital technologies (DTs) in humanitarian supply chains (HSC) has become an increasingly researched topic in the operations literature. While numerous publications have dealt with this convergence, most studies have focused on examining the implementation of individual DTs within the HSC context, leaving relevant literature, to date, dispersed and fragmented. This study, through a systematic literature review of 110 articles on HSC published between 2015 and 2020, provides a unified overview of the current state-of-the-art DTs adopted in HSC operations. The literature review findings substantiate the growing significance of DTs within HSC, identifying their main objectives and application domains, as well as their deployment with respect to the different HSC phases (i.e., Mitigation, Preparedness, Response, and Recovery). Furthermore, the findings also offer insight into how participant organizations might configure a technological portfolio aimed at overcoming operational difficulties in HSC endeavours. This work is novel as it differs from the existing traditional perspective on the role of individual technologies on HSC research by reviewing multiple DTs within the HSC domain

Cross-dehydrogenative coupling reaction using copper oxide impregnated on magnetite in deep eutectic solvents

The synthesis of different tetrahydroisoquinolines using choline chloride : ethylene glycol as a deep eutectic solvent (DES) and copper(II) oxide impregnated on magnetite as a catalyst has been accomplished successfully. The copper catalyst amount is the lowest loading ever reported. The presence of DES showed to be essential since the reaction in the absence of this medium did not proceed. A direct proportional relationship was found between the conductivity of DES medium and the yield obtained. The DES and the catalyst could be reused up to ten times without any detrimental effect on the yield of the reaction, with the aerobic conditions making the protocol highly sustainable, where the only waste is water.This work was supported by the Spanish Ministerio de Economía y Competitividad (MICINN; CTQ2011-24151) and the University of Alicante. J. M. P. thanks the MICINN (FPI program) for her fellowship

Multicomponent Azide-Alkyne Cycloaddition Catalyzed by Impregnated Bimetallic Nickel and Copper on Magnetite

A new bimetallic catalyst derived from nickel and copper has been used successfully for the first time in the multicomponent reaction of terminal alkynes, sodium azide, and benzyl bromide derivatives. The presence of both metallic species on the surface of magnetite seems to have a positive and synergetic effect. The catalyst loading is the lowest ever published for a catalyst of copper anchored on any type of iron support. The catalyst could be easily removed from the reaction media just by magnetic decantation and it could be reused up to ten times without any negative effect on the initial results

Osmium impregnated on magnetite as a heterogeneous catalyst for the syn-dihydroxylation of alkenes

A new catalyst derived from osmium has been prepared, fully characterized and tested in the dihydroxylation of alkenes. The catalyst was prepared by wet impregnation methodology of OsCl3·3H2O on a commercial micro-magnetite surface. The catalyst allowed the reaction with one of the lowest osmium loadings for a heterogeneous catalyst and was selective for the monodihydroxylation of 1,5-dienes. Moreover, the catalyst was easily removed from the reaction medium by the simple use of a magnet. The selectivity of catalyst is very high with conversions up to 99%. Preliminary kinetics studies showed a first-order reaction rate with respect to the catalyst.This work was supported by the Spanish Ministerio de Economía y Competitividad (CTQ2011-24151). J. M. P. thanks the M.E.C. for a fellowship through the FPI program

What affects the probability of biological invasions in Antarctica? Using an expanded conceptual framework to anticipate the risk of alien species expansion

Successful alien species invasion depends on many factors studied mostly in post invasion habitats, and subsequently summarized in frameworks tailored to describe the studied invasion. We used an existing expanded framework with three groups of contributing factors: habitat invisibility, system context and species invasiveness, to analyze the probability of alien species invasions in terrestrial communities of Maritime Antarctic in the future. We focused on the first two factor groups. We tested if the expanded framework could be used under a different scenario. We chose Point Thomas Oasis on King George Island to perform our analysis. Strong geographical barrier, low potential bioclimatic suitability and resource availability associated with habitat invasibility significantly reduce the likelihood of biological invasion in Antarctica. An almost full enemy release (low pressure of consumers), the high patchiness of the habitat, and the prevalence of open gaps also associated with habitat invasibility increase the possibility of invasion. The dynamics of functional connectivity, propagule pressure and spatio-temporal patterns of propagule arrival associated with human activity and climate change belonging to the system context contribute to an increase in the threat of invasions. Due to the still low land transport activity migration pathways are limited and will reduce the spread of alien terrestrial organisms by land. An effective way of preventing invasions in Antarctica seems to lie in reducing propagule pressure and eliminating alien populations as early as possible. The expanded conceptual framework opens up wider possibilities in analyzing invasions taking place in different systems and with multiple taxa

Tuning the van der Waals Interaction of Graphene with Molecules via Doping

We use scanning tunneling microscopy to visualize and thermal desorption spectroscopy to quantitatively measure that the binding of naphthalene molecules to graphene (Gr), a case of pure van der Waals (vdW) interaction, strengthens with $n$- and weakens with $p$-doping of Gr. Density functional theory calculations that include the vdW interaction in a seamless, ab initio way accurately reproduce the observed trend in binding energies. Based on a model calculation, we propose that the vdW interaction is modified by changing the spatial extent of Gr's $\pi$ orbitals via doping

The cadherin–catenin complex in nasopharyngeal carcinoma

Abnormal Wnt signaling and impaired cell–cell adhesion due to abnormal E-cadherin and b-catenin func tion have been implicated in many cancers, but have not been fully explored in nasopharyngeal carcinoma. The aim of this study was to analyze b-Catenin cellular location and E-cadherin expression levels in nasopharyngeal carcinoma. E-cadherin expression levels were also correlated with clinical data and underlying pathology. b-Catenin and E-cadherin expression were examined in 18 nasopharyn geal carcinoma and 7 non-tumoral inflammatory pharynx tissues using immunohistochemical methods. Patient clin ical data were collected, and histological evaluation was performed by hematoxylin/eosin staining. b-catenin was detected in membrane and cytoplasm in all cases of naso pharyngeal carcinoma, regardless of histological type; in non-tumoral tissues, however, b-catenin was observed only in the membrane. As for E-cadherin expression levels, strong staining was observed in most non-tumoral tissues, but staining was only moderate in nasopharyngeal carci noma tissues. E-cadherin expression was associated with b-catenin localization, study group, metastatic disease, and patient outcomes. Reduced levels of E-cadherin protein observed in nasopharyngeal carinoma may play an important role in invasion and metastasis. Cytoplasmic b-catenin in nasopharyngeal carcinoma may impair cell– cell adhesion, promoting invasive behavior and a metastatic tumor phenotype