Mechanism of Alkyl Migration in Diorganomagnesium 2,6-Bis(imino)pyridine Complexes: Formation of Grignard-Type Complexes with Square-Planar Mg(II) Centers

Dialkylmagnesium compounds [MgR2L2] (R = n-Bu, L = none or R = Bn, L = THF) react with 2,6-bis(imino)pyridines (BIP) to afford different types of Mg(II) alkyl complexes, depending on the nature of R. For R = n-Bu, thermally stable products resulting from selective alkyl transfer to the pyridine nitrogen (N1) atom are obtained. However, NMR studies showed that the reaction of [Mg(Bn)2THF2] with iPrBIP at −65 °C leads to a thermally unstable product arising from benzyl migration to position C2 in the pyridine ring. Above +5 °C, this compound rearranges, cleanly yielding a mixture of two isomeric complexes, in which the benzyl group has migrated to positions C3 or C4 of the central ring, respectively. Similar isomeric mixtures were obtained when [Mg(Bn)2THF2] was reacted with iPrBIP or MesBIP at room temperature. Such mixtures are thermally stable below 80 °C, but at this temperature, the 3-benzyl isomer converts into the thermodynamically favored 4-benzyl product, albeit not quantitatively. An alternate route was devised for the selective syntheses of the latter type of compounds. The X-ray diffraction structure of one of them provided an unusual example of a square-planar alkylmagnesium(II) center.Ministerio de Economía e Innovación CTQ2015-68978-

Social work education: ISCTE University Institute of Lisbon/Portugal

ISCTE-IUL 1that is a public university established in 1972 pursuing teaching, research and community service activities. With more than 9000 students enrolled in undergraduate (46%) and postgraduate (54%) programs, 450 teachers and 240 non-teaching staff, the University is proud to be one of the most dynamic and innovative universities in the country producing, transmitting and transferring knowledge to society according with the highest international standards. It is a research oriented university with a multi-disciplinary and inter-disciplinary approach, that includes eight research units, six laboratories, as well as the Departments and Schools that are the main organizational structures of the Institute (see www.iscte-iul.pt). The research units have high quality and national merit and with significant contributions of international relevance in their research areas. CIES-IUL's is one of these research units and has as main scientific domain sociology, developing also relevant activity in the fields of public policy, political science, communication, education, modern and contemporary history and social work.info:eu-repo/semantics/acceptedVersio

Search for Long-Lived Heavy Neutrinos at the LHC with a VBF Trigger

The charged current production of long-lived heavy neutrinos at the LHC can use a prompt charged lepton for triggering the measurement of the process. However, in order to fully characterize the heavy neutrino interactions, it is necessary to also probe Higgs or $Z$ mediated neutral current production. In this case the charged lepton is not available, so other means of triggering are required. In this work, we explore the possibility of using a vector boson fusion trigger in the context of a GeV-scale Type I Seesaw model. We consider a minimal model, where both Higgs and Z-mediated contributions produce one heavy neutrino, as well as an extended model where the Higgs can decay into two heavy ones. Both scenarios are tested through displaced dilepton and displaced multitrack jet searches.Comment: 31 pages, 1 appendix, 5 figures; v2: improved version, accepted for publication in EPJ

Oxygen-Induced Dimerization of Alkyl-Manganese(II) 2,6-Bisiminopyridine Complexes: Selective Synthesis of a New Ditopic NNN-Pincer Ligand

The outcome of the reaction of manganese(II) dialkyls with 2,6-bisiminopyridine (BIP) ligands is dramatically altered by the presence of very small amounts of oxygen (< 0.5 mol %), leading to binuclear species. These arise from the dimerization of the initial product, a Mn(II) 4-alkyl-2,6-bisiminodihydropyridinate alkyl complex. Cleavage of the binuclear Mn products with methanol affords the free dimeric bases, which can be regarded as a special type of ditopic NNN pincer ligand with an unusual tricyclic framework. The coordinative ability of the new ligands has been probed with the syntheses of Zn and Pd organometallic derivativesMinisterio de Economía e Innovación TQ2015- 68978-

El desarrollo de competencias científicas a través de una experiencia de introducción de la historia de las ciencias y las técnicas en el aula

Se presenta una experiencia de formación de profesorado universitario referente a la introducción de la HCT en la enseñanza, que pretendía: -Detectar ideas previas sobre HCT y modelos de ciencia -Analizar textos histórico científicos -Reflexionar sobre diferentes visiones de la ciencia -Estudiar contribuciones de las mujeres a la ciencia -Situar los conocimientos tecnocientíficos en su contexto -Mostrar las relaciones CTS -Evaluar la utilidad de la HCT para el desarrollo de competencias científicas. Se constató la utilidad de la HCT para: -Mostrar el modelo de ciencia subyacente -Comprender las interacciones CTS y Género -Motivar al alumnado Se constató la necesidad de: -Adquirir conocimientos de HCT -Profundizar en las metodologías para la introducción de la HCT en el aula -Adaptar textos originales -Replicar experimentos -Organizar nuevas acciones formativas

Multilevel Multiphase Feedforward Space-Vector Modulation Technique

Multiphase converters have been applied to an increasing number of industrial applications in recent years. On the other hand, multilevel converters have become a mature technology mainly in medium- and high-power applications. One of the problems of multilevel converters is the dc voltage unbalance of the dc bus. Depending on the loading conditions and the number of levels of the converter, oscillations appear in the dc voltages of the dc link. This paper presents a feedforward modulation technique for multilevel multiphase converters that reduces the distortion under balanced or unbalanced dc conditions. The proposed modulation method can be applied to any multilevel-converter topology with any number of levels and phases. Experimental results are shown in order to validate the proposed feedforward modulation technique.Ministerio de Ciencia e Innovación DPI2009-07004Ministerio de Eduación y Ciencia TEC2007-6187

Papel del estrés óxidativo en la periodontitis y diabetes tipo 2

Universidad de Sevilla. Máster en Ciencias Odontológica

Defense and Attack Techniques against File-based TOCTOU Vulnerabilities: a Systematic Review

File-based Time-of-Check to Time-of-Use (TOCTOU) race conditions are a well-known type of security vulnerability. A wide variety of techniques have been proposed to detect, mitigate, avoid, and exploit these vulnerabilities over the past 35 years. However, despite these research efforts, TOCTOU vulnerabilities remain unsolved due to their non-deterministic nature and the particularities of the different filesystems involved in running vulnerable programs, especially in Unix-like operating system environments. In this paper, we present a systematic literature review on defense and attack techniques related to the file-based TOCTOU vulnerability. We apply a reproducible methodology to search, filter, and analyze the most relevant research proposals to define a global and understandable vision of existing solutions. The results of this analysis are finally used to discuss future research directions that can be explored to move towards a universal solution to this type of vulnerability. Autho