Suchergebnisse

We acknowledge the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC-2015-STG-677023 and ERC-2013-SYG-610256 NANOCOSMOS) and the innovation program under grant agreement No. 696656 (GrapheneCore1-Graphene-based disruptive technologies) and grant agreement No. 785219 (GrapheneCore2-Graphene-based disruptive technologies) for financial support. Grants PGC2018-101181-B-I00 and MAT2017-85089-C2-1-R funded by MCIN/AEI/ 10.13039/501100011033 and "ERDF A way of making Europe" by the "European Union", and grant PID2020-113142RB-C21 funded by MCIN/AEI/ 10.13039/501100 011033 also provided financial support. We also acknowledge Comunidad de Madrid via Programa de Investigación Tecnologías 2018 (FOTOART-CM S2018/NMT-4367), the Swiss National Science Foundation (grant number 200020-182015), the NCCR MARVEL funded by the Swiss National Science Foundation (grant number 51NF40-182892) and FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento (B-FQM-428-UGR20). C. S. S. and N. R. A. acknowledge Grants RYC2018-024364-I and BES-2015-072642, respectively, funded by MCIN/AEI/ 10.13039/501100011033 and "ESF Investing in your future". I. R. M. acknowledges the University of Granada for her postdoctoral contract (Contrato Puente-Plan Propio UGR). F.V. thanks Ministerio de Universidades for the FPU grant (FPU18/05938). ; On-surface synthesis, complementary to wet chemistry, has been demonstrated to be a valid approach for the synthesis of tailored graphenic nanostructures with atomic precision. Among the different existing strategies used to tune the optoelectronic and magnetic properties of these nanostructures, the introduction of non-hexagonal rings inducing out-of-plane distortions is a promising pathway that has been scarcely explored on surfaces. Here, we demonstrate that non-hexagonal rings, in the form of tropone (cycloheptatrienone) moieties, are thermally transformed into phenyl or cyclopentadienone moieties upon an unprecedented surface-mediated retro–Buchner-type reaction involving a decarbonylation or an intramolecular rearrangement of the CO unit, respectively. ; Junta de Andalucía-Consejería de Economía y Conocimiento B-FQM-428-UGR20, BES-2015-072642, RYC2018-024364-I ; MCIN ; Ministerio de Universidades FPU18/05938 ; European Commission FOTOART-CM S2018/NMT-4367 ; European Research Council ; Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung 200020-182015 ; European Social Fund ; Universidad de Granada ; European Regional Development Fund 011033, PID2020-113142RB-C21, S2018/NMT-4367 ; National Center of Competence in Research Materials' Revolution: Computational Design and Discovery of Novel Materials 51NF40-182892 ; Agencia Estatal de Investigación

This review highlights the recent applications of titanocene(III) complexes in the field of natural product synthesis from the seminal precedents to the development of modern catalytic methods. The power of the titanocene(III)-based approaches is demonstrated by the straightforward syntheses of many natural products from readily available starting materials. ; We thank the Regional Government of Andalucía (project P09-FQM-4571), MICINN (project CTQ-2011.22455), and CEI-Biotic for financial support. SPM thanks the Regional Government of Andalucía for her FPI fellowship. DM and AGC thank the Regional Government of Andalucía and the MICINN ( Juan de la Cierva) for their postdoctoral contracts.

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fchem. 2020.00306/full#supplementary-material ; In this work we describe the linear and non-linear (chiro)optical properties of an enantiopure bis-perylenediimide (PDI) cyclohexane derivative. This compound exhibits upconversion based on a two-photon absorption (TPA) process with a cross-section value of 70 GM together with emission of circularly polarized luminescence (CPL), showing a glum in the range of 10−3. This simple structure represents one of the scarce examples of purely organic compounds combining both TPA and CPL responses, together with large values of molar absorptivity and fluorescence quantum yield with emission in the 500–600 nm. Self-assembly induced by introduction of a poor solvent allows for a spectacular shift of the emission into the near-infrared (NIR, 650–750 nm) by formation of well-defined rotationally displaced dimers. Therefore, we are here presenting a versatile platform whose optical properties can be simply tuned by self-assembly or by functionalization of the electron-deficient aromatic core of PDIs. ; Ministerio de Ciencia, Innovacion y Universidades PG2018-101181-B-I00 ; Spanish Government CTQ2017-85454-C2-1-P ; European Research Council (ERC) ERC-2015-STG-677023 ; MINECO RyC-2013-12943 ; Spanish Government ; Portuguese Foundation for Science and Technology ; POCI ; European Union (EU) PTDC/NAN-MAT/29317/2017 PTDC/QUI-QFI/29319/2017 UIDB/00100/2020

We thank the Ministerio de Economia y Competitividad (CTQ2017-85454-C2-1-P and CTQ2017-85454-C2-2-P), Ministerio de Ciencia e Innovacion (PID2020-113059GB-C21 and PID2020-113059GB-C22) and Junta de Andalucia (P20.00162) (Spain) for funding and P.R. and A. O. G. also for FPU contracts. Funding for open access charge is acknowledged to Universidad de Granada / CBUA.We also thank Big&Open Data Innovation Laboratory (BODaI-Lab), University of Brescia, granted by Fondazione Cariplo and Regione Lombardia, for access to resources of Computing Center CINECA (Bologna), Italy. Support from the Italian MIUR (Grant No. 2017A4XRCA) is also acknowledged. ; In this paper, we describe the optical and chiroptical properties of an enantiopure multipodal ortho-oligophenylethynylene (S,S,S,S)-1 presenting four chiral sulfoxide groups at the extremes. The presence of these groups together with alkynes allows the coordination with carbophilic Ag(I), and/or oxophilic Zn(II) cations, yielding double helical structures in an enantiopure way. In this sense, different behaviors in absorption, fluorescence, ECD and CPL spectra have been found depending on the stoichiometry and nature of the metal. We have observed that Zn(II) coordination favors an intensity increase of the electronic circular dichroism (ECD) spectra of compound (S,S,S,S)-1 yielding an M-helicity in the ortho-oligophenylene ethynylene (o-OPE) backbone. On the other hand, ECD spectra of final Ag(I) complex shows two different bands with an opposite sign to the free ligand, thus giving the P-helical isomer. In addition, circularly polarized luminescence (CPL) exhibit an enhanced intensity and negative sign in both complexes. Computational studies were also carried out, supporting the experimental results. ; Spanish Government CTQ2017-85454-C2-1-P CTQ2017-85454-C2-2-P ; Instituto de Salud Carlos III Spanish Government European Commission PID2020-113059GB-C21 PID2020-113059GB-C22 ; Junta de Andalucia European Commission P20.00162 ; University of Brescia / CBUA ; Fondazione Cariplo ; Ministry of Education, Universities and Research (MIUR) 2017A4XRCA ; Regione Lombardia

In recent years, the prevalence of amyloid neurodegenerative diseases such as Alzheimer's disease (AD) has significantly increased in developed countries due to increased life expectancy. This amyloid disease is characterized by the presence of accumulations and deposits of β-amyloid peptide (Aβ) in neuronal tissue, leading to the formation of oligomers, fibers, and plaques. First, oligomeric intermediates that arise during the aggregation process are currently thought to be primarily responsible for cytotoxicity in cells. This work aims to provide further insights into the mechanisms of cytotoxicity by studying the interaction of Aβ aggregates with Neuro-2a (N2a) neuronal cells and the effects caused by this interaction. For this purpose, we have exploited the advantages of advanced, multidimensional fluorescence microscopy techniques to determine whether different types of Aβ are involved in higher rates of cellular toxicity, and we measured the cellular stress caused by such aggregates by using a fluorogenic intracellular biothiol sensor. Stress provoked by the peptide is evident by N2a cells generating high levels of biothiols as a defense mechanism. In our study, we demonstrate that Aβ aggregates act as seeds for aggregate growth upon interacting with the cellular membrane, which results in cell permeability and damage and induces lysis. In parallel, these damaged cells undergo a significant increase in intracellular biothiol levels. ; Spanish Ministerio de Ciencia, Innovacion y Universidades CTQ2014-56370-R CTQ2017-86568-R CTQ2017-86125-P ; Spanish Agencia Estatal de Investigacion ; European Union (EU)

This is accepted manuscript, the final published article is available in "García Jiménez, V.; et al. Aggregation-induced emission of [3]cumulenes functionalized with heptagon-containing polyphenylenes. Chemical Communications, online (2018). DOI: http://dx.doi.org/10.1039/C8CC00386F ; We report the luminiscence at room temperature by aggregate formation of [3]cumulenes functionalized with propeller-like heptagon-containing polyphenylenes. These endgroups turn on the emission of a [3]cumulene by steric protection and restriction of their intramolecular rotations in the aggregates. ; European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (ERC-2015 -677023). ; Ministerio de Economía y Competitividad (MINECO, Spain – FEDER) (CTQ2015-70283-P, CTQ2014-53598-R, RyC-2013-12943). ; Fundação para a Ciência e a tecnologia (Portugal, IF/00759/2013, SFRH/BPD/75782/2011,SFRH/BPD/96707/2013,UID/NAN/50024/2013).

This study was supported by projects CTQ2017-86568-R and FIS2017-85954-R (Ministerio de Economia, Industria y Competitividad, MINECO, and Agencia Estatal de Investigacion, AEI, Spain, cofunded by Fondo Europeo de Desarrollo Regional, FEDER, European Union), and by FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) project P18-FR-3533. We want to thank "Unidad de Excelencia Quimica aplicada a Biomedicina y Medioambiente" of the University of Granada. Thanks go to the CIC personnel of the University of Granada for technical assistance. We thank the Centro de Servicios de Informatica y Redes de Comunicaciones (CSIRC), Universidad de Granada, for providing the computing time. Authors acknowledge to Dr Rosario Herranz and Dr Francisco Fueyo-Gonzalez for the fluorophore 9-azetidinyl-5-butyl-quinolimide (AQui) used in this study, which was synthesized at Instituto de Quimica Medica-CSIC (IQM-CSIC) with the support of the Ministerio de Ciencia e Innovacion/Agencia Estatal de Investigacion grant FU2015-67284-R. ; Making use of the combination of multiparametric Fluorescence Lifetime Imaging Microscopy (FLIM) and single-molecule Fluorescence Lifetime Correlation Spectroscopy (FLCS), we have been able to study for the early stages of the fluorenylmethyloxycarbonyl-diphenylalanine (Fmoc-FF) self-assembly process with single-molecule resolution, the kinetics of fiber formation, the packaging of the peptides within the fibers and the capacity of the peptides to reassemble after disruption (self-healing) in the presence of different metallic cations. Other techniques such as FTIR, TEM, DSC and DFT calculations support our findings. The impact that the mechanism of self-assembly has on the physical (rigidity and self-healing) properties of the resulting gels have also been evaluated by rheology. Calcium ions are able to promote the self-assembly of Fmoc-FF faster and more efficiently, forming more rigid hydrogels than do cesium ions. The reasons behind this effect may be explained by the different capacities that these two cations have to coordinate with the peptide, modulate its hydrophobicity and stabilize the water-solute interphase. These findings shed light on the impact that small changes have on the process of self-assembly and can help to understand the influence of the environmental conditions on the in vivo uncontrolled self-assembly of certain proteins. ; Ministerio de Economia, Industria y Competitividad, MINECO CTQ2017-86568-R FIS2017-85954-R ; Agencia Estatal de Investigacion, AEI, Spain CTQ2017-86568-R FIS2017-85954-R ; Fondo Europeo de Desarrollo Regional, FEDER, European Union CTQ2017-86568-R FIS2017-85954-R ; FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) P18-FR-3533 ; Ministerio de Ciencia e Innovacion/Agencia Estatal de Investigacion FU2015-67284-R