Expedient Iodocyclization Approach Toward Polysubstituted 3H-Benzo[e]indoles

A facile and expedient iodocyclization of 4-(2-prop-1-ynylphenyl)-1H-pyrroles towards the synthesis of polysubstituted 3H-benzo[e]indoles is reported. The transformation was optimized and the best results were obtained by using iodine (1.2 equiv,) in dichloromethane, and potassium carbonate as base. The starting 1,2,3,4-tetrasubstituted pyrroles were efficiently obtained by means of a nickel(II) chloride-promoted four-component (nitromethane, amine, 2-alkynylbenzaldehyde and ethyl acetoacetate) reaction. Further functionalization of the resulting 5-iodoheterocycles was also explored.Fil: Martins, Guilherme M.. Universidade Federal de Santa Maria. Departamento de Qu ímica; BrasilFil: Zeni, Gilson. Universidade Federal de Santa Maria. Departamento de Qu ímica; BrasilFil: Back, David F.. Universidade Federal de Santa Maria. Departamento de Qu ímica; BrasilFil: Kaufman, Teodoro Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Silveira, Claudio C.. Universidade Federal de Santa Maria. Departamento de Qu ímica; Brasi

Data-driven simulation and characterisation of gold nanoparticle melting

The simulation and analysis of the thermal stability of nanoparticles, a stepping stone towards their application in technological devices, require fast and accurate force fields, in conjunction with effective characterisation methods.In this work, we develop efficient, transferable, and interpretable machine learning force fields for gold nanoparticles based on data gathered from Density Functional Theory calculations.We use them to investigate the thermodynamic stability of gold nanoparticles of different sizes (1 to 6 nm), containing up to 6266 atoms, concerning a solid-liquid phase change through molecular dynamics simulations.We predict nanoparticle melting temperatures in good agreement with available experimental data.Furthermore, we characterize the solid-liquid phase change mechanism employing an unsupervised learning scheme to categorize local atomic environments.We thus provide a data-driven definition of liquid atomic arrangements in the inner and surface regions of a nanoparticle and employ it to show that melting initiates at the outer layers

A Surface Plasmon Resonance Plastic Optical Fiber Biosensor for the Detection of Pancreatic Amylase in Surgically-Placed Drain Effluent

Postoperative pancreatic fistula (POPF), the major driver of morbidity and mortality following pancreatectomy, is caused by an abnormal communication between the pancreatic ductal epithelium and another epithelial surface containing pancreas-derived, enzyme-rich fluid. There is a strong correlation between the amylase content in surgically-placed drains early in the postoperative course and the development of POPF. A simple and cheap method to determine the amylase content from the drain effluent has been eagerly advocated. Here, we developed an amylase optical biosensor, based on a surface plasmon resonance (SPR) plastic optical fiber (POF), metallized with a 60 nm layer of gold and interrogated with white light. The sensor was made specific by coupling it with an anti-amylase antibody. Each surface derivatization step was optimized and studied by XPS, contact angle, and fluorescence. The POF-biosensor was tested for its response to amylase in diluted drain effluents. The volume of sample required was 50 \ub5L and the measurement time was 8 min. The POF-biosensor showed selectivity for amylase, a calibration curve log-linear in the range of 0.8\u201325.8 U/L and a limit of detection (LOD) of ~0.5 U/L. In preliminary tests, the POF-biosensor allowed for the measurement of the amylase content of diluted surgically-placed drain effluents with an accuracy of >92% with respect to the gold standard. The POF-biosensor allows for reliable measurement and could be implemented to allow for a rapid bedside assessment of amylase value in drains following pancreatectomy

A Long-Term Conserved Satellite DNA That Remains Unexpanded in Several Genomes of Characiformes Fish Is Actively Transcribed

Eukaryotic genomes contain large amounts of repetitive DNA sequences, such as tandemly repeated satellite DNAs (satDNAs). These sequences are highly dynamic and tend to be genus- or species-specific due to their particular evolutionary pathways, although there are few unusual cases of conserved satDNAs over long periods of time. Here, we used multiple approaches to reveal that an satDNA named CharSat01-52 originated in the last common ancestor of Characoidei fish, a superfamily within the Characiformes order, ∼140-78 Ma, whereas its nucleotide composition has remained considerably conserved in several taxa. We show that 14 distantly related species within Characoidei share the presence of this satDNA, which is highly amplified and clustered in subtelomeric regions in a single species (Characidium gomesi), while remained organized as small clusters in all the other species. Defying predictions of the molecular drive of satellite evolution, CharSat01-52 shows similar values of intra- and interspecific divergence. Although we did not provide evidence for a specific functional role of CharSat01-52, its transcriptional activity was demonstrated in different species. In addition, we identified short tandem arrays of CharSat01-52 embedded within single-molecule real-time long reads of Astyanax paranae (536 bp-3.1 kb) and A. mexicanus (501 bp-3.9 kb). Such arrays consisted of head-to-tail repeats and could be found interspersed with other sequences, inverted sequences, or neighbored by other satellites. Our results provide a detailed characterization of an old and conserved satDNA, challenging general predictions of satDNA evolution

The Satellite Data Thematic Core Service within the EPOS Research Infrastructure

Trabajo presentado en la European Geosciences Union General Assembly, celebrada en Viena (Austria), del 23 al 28 de abril de 2017EPOS, the European Plate Observing System, is a long-term plan to facilitate the integrated use of data, data products, software and services, available from distributed Research Infrastructures (RI), for solid Earth science in Europe. Indeed, EPOS integrates a large number of existing European RIs belonging to several fields of the Earth science, from seismology to geodesy, near fault and volcanic observatories as well as anthropogenic hazards. The EPOS vision is that the integration of the existing national and trans-national research infrastructures will increase access and use of the multidisciplinary data recorded by the solid Earth monitoring networks, acquired in laboratory experiments and/or produced by computational simulations. The establishment of EPOS will foster the interoperability of products and services in the Earth science field to a worldwide community of users. Accordingly, the EPOS aim is to integrate the diverse and advanced European Research Infrastructures for solid Earth science, and build on new e-science opportunities to monitor and understand the dynamic and complex solid-Earth System. One of the EPOS Thematic Core Services (TCS), referred to as Satellite Data, aims at developing, implementing and deploying advanced satellite data products and services, mainly based on Copernicus data (namely Sentinel acquisitions), for the Earth science community. This work intends to present the technological enhancements, fostered by EPOS, to deploy effective satellite services in a harmonized and integrated way. In particular, the Satellite Data TCS will deploy five services, EPOSAR, GDM, COMET, 3D-Def and MOD, which are mainly based on the exploitation of SAR data acquired by the Sentinel-1 constellation and designed to provide information on Earth surface displacements. In particular, the planned services will provide both advanced DInSAR products (deformation maps, velocity maps, deformation time series) and value-added measurements (source model, 3D displacement maps, seismic hazard maps). Moreover, the services will release both on-demand and systematic products. The latter will be generated and made available to the users on a continuous basis, by processing each Sentinel-1 data once acquired, over a defined number of areas of interest; while the former will allow users to select data, areas, and time period to carry out their own analyses via an on-line platform. The satellite components will be integrated within the EPOS infrastructure through a common and harmonized interface that will allow users to search, process and share remote sensing images and results. This gateway to the satellite services will be represented by the ESA- Geohazards Exploitation Platform (GEP), a new cloud-based platform for the satellite Earth Observations designed to support the scientific community in the understanding of high impact natural disasters. Satellite Data TCS will use GEP as the common interface toward the main EPOS portal to provide EPOS users not only with data products but also with relevant processing and visualisation software, thus allowing users to gather and process on a cloud-computing infrastructure large datasets without any need to download them locallyPeer reviewe

Oxidative addition of organic halides on palladium(0) complexes stabilized by dimethylfumarate and quinoline-based N-P or N-S spectator ligands

We have studied the oxidative addition of some organic halides on palladium(0) dimethylfumarate complexes bearing heteroditopic (N–P or N–S) quinoline-based spectator ligands from the experimental and theoretical point of view. We have measured the half-life of some oxidative addition reactions carried out in two different solvents (CD2Cl2 and CD3CN). The reactions were studied under mild conditions by NMR and the reactivities of different oxidants towards the complexes under study were compared. The rates of reaction were influenced by the nature of the spectator ligands and the solvent. The thioquinoline derivatives display a higher reactivity than that of the phosphoquinoline complexes and in general the reaction rates are higher in CD3CN than in CD2Cl2, although such a behavior is not always observed. We propose a plausible mechanism for the oxidative reaction in different solvents based on the experimental results and an adequate computational approach. Finally, the solid state structures of two reaction products were resolved and reported.We have studied the oxidative addition of some organic halides on palladium(0) dimethylfumarate complexes bearing heteroditopic (N-P or N-S) quinoline-based spectator ligands from the experimental and theoretical point of view. We have measured the half-life of some oxidative addition reactions carried out in two different solvents (CD2Cl2 and CD3CN). The reactions were studied under mild conditions by NMR and the reactivities of different oxidants towards the complexes under study were compared. The rates of reaction were influenced by the nature of the spectator ligands and the solvent. The thioquinoline derivatives display a higher reactivity than that of the phosphoquinoline complexes and in general the reaction rates are higher in CD3CN than in CD2Cl2, although such a behavior is not always observed. We propose a plausible mechanism for the oxidative reaction in different solvents based on the experimental results and an adequate computational approach. Finally, the solid state structures of two reaction products were resolved and reported. (C) 2015 Elsevier Ltd. All rights reserved

The addition of bromine and iodine to palladacyclopentadienyl complexes bearing bidentate heteroditopic P-N spectator ligands derived from differently substituted quinolinic frames. The unexpected evolution of the reaction

We have synthesized two palladacyclopentadienyl derivatives bearing bidentate ligands heteroditopic 8-(diphenylphosphino)quinoline or 8-(diphenylphosphino)-2-methylquinoline. We have reacted the palladacyclopentadienyl complexes with Br2 and I2 to gain clues on the formation mechanism of the corresponding σ-butadienyl derivatives. We were able to obtain the pure σ-butadienyl derivative only in the case of Br2 reacting with the palladacyclopentadienyl complex bearing the unsubstituted quinoline. However, an equilibrium mixture of the σ-butadienyl and a novel zwitterionic species was obtained when the same complex reacts with I2. Furthermore, we have obtained exclusively an unprecedented zwitterionic complex when I2 reacts with the palladacyclopentadienyl complex bearing the substituted quinoline and a different ratio of an equilibrium mixture of σ-butadienyl and the zwitterionic species when the latter derivative reacts with Br2. The solid state structures of one σ-butadienyl complex and of the two novel zwitterionic derivatives were determined and an interpretation of the observed reactivity based on kinetic data and a computational study has been suggested