194 research outputs found

    Mobility infrastructures in cities and climate change: An analysis through the superblocks in Barcelona

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    Cities are key actors in the fight against climate change since they are major sources of greenhouse gas (GHG) emissions while at the same time they experience the negative impact of this phenomenon. Mitigating and adapting to climate change requires fundamental changes in urbanism and city automobile traffic. Superblocks, a grid of blocks and basic roads forming a polygon, approximately 400 by 400 m, are one of the instruments for such changes. These type of city Superblocks represent a new model of mobility that restructures the typical urban road network, thereby substantially reducing automobile traffic, and accordingly GHG emissions, while increasing green space in the city and improving the health and quality of life of its inhabitants.Furthermore, the Superblocks do not require investment in hard infrastructures, nor do they involvedemolishing buildings or undertaking massive development; they are in fact very low-tech urbanism.The city of Barcelona has been implementing Superblocks as one of the measures to combat climate change with very positive results. The paper analyzes the concept of the Superblock and its relation with climate change in cities. Along these lines, it analyzes the pioneer experience of Barcelona in the development and implementation of the Superblocks, as a radical plan aimed at taking back the streets from cars. The role of political power and institutional leadership has been key in societal acceptance and the achievement of tangible results. But there are also obstacles and drawbacks in the development of these types of Superblocks, such as the necessity to redesign the collective transport network so that car traffic can truly be reduced in cities, the possible negative influence on traffic going in and out of the city, the lack of visible advantages if they are not implemented in the entire city, the risk of gentrification in the areas with Superblocks, public opposition, and opposition from certain sectors of the business communityPostprint (published version

    Las cuotas de emisiones de CO2 individuales y comerciales

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    Statistical energy analysis model for sound pressure level prediction on refrigerators

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s40857-020-00188-0A Statistical Energy Analysis (SEA) model of a 510 liter capacity refrigerator is used to calculate the Sound Pressure Level (SPL) generated in a reverberation room. This is a reliable indicator of the vibroacoustic performance of the refrigerator and it is in some countries as a pre-commercialization test. The main contributions of the SEA model are, the characterization of the refrigerator structure (three-layer: HIPS, polyurethane foam and steel), and the modeling of important components such as internal chambers or ventilation gratings. The simulation results are successfully compared with laboratory measurements. The SEA model is then used to understand the vibroacoustic behavior of the refrigerator and to establish the most critical transmission paths and radiation mechanisms.Peer ReviewedPostprint (author's final draft

    Solution-based synthesis and processing of Sn- and Bi-doped Cu3SbSe4 nanocrystals, nanomaterials and ring-shaped thermoelectric generators

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    Copper-based chalcogenides that comprise abundant, low-cost, and environmental friendly elements are excellent materials for a number of energy conversion applications, including photovoltaics, photocatalysis, and thermoelectrics (TE). In such applications, the use of solution-processed nanocrystal (NC) to produce thin films or bulk nanomaterials has associated several potential advantages, such as high material yield and throughput, and composition control with unmatched spatial resolution and cost. Here we report on the production of Cu3SbSe4 (CASe) NCs with tuned amounts of Sn and Bi dopants. After proper ligand removal, as monitored by nuclear magnetic resonance and infrared spectroscopies, these NCs were used to produce dense CASe bulk nanomaterials for solid state TE energy conversion. By adjusting the amount of extrinsic dopants, dimensionless TE figures of merit (ZT) up to 1.26 at 673 K were reached. Such high ZT values are related to an optimized carrier concentration by Sn doping, a minimized lattice thermal conductivity due to efficient phonon scattering at point defects and grain boundaries, and to an increase of the Seebeck coefficient obtained by a modification of the electronic band structure with the Bi doping. Nanomaterials were further employed to fabricate ring-shaped TE generators to be coupled to hot pipes and which provided 20 mV and 1 mW per TE element when exposed to a 160 °C temperature gradient. The simple design and good thermal contact associated with the ring geometry and the potential low cost of the material solution processing may allow the fabrication of TE generators with short payback times.Peer ReviewedPostprint (author's final draft

    Microfluidic-based dynamic BH3 profiling predicts anticancer treatment efficacy

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    Cancer therapy; Predictive markers; Translational researchTerapia del cáncer; Marcadores predictivos; Investigación traslacionalTeràpia del càncer; Marcadors predictius; Recerca translacionalPrecision medicine is starting to incorporate functional assays to evaluate anticancer agents on patient-isolated tissues or cells to select for the most effective. Among these new technologies, dynamic BH3 profiling (DBP) has emerged and extensively been used to predict treatment efficacy in different types of cancer. DBP uses synthetic BH3 peptides to measure early apoptotic events (‘priming’) and anticipate therapy-induced cell death leading to tumor elimination. This predictive functional assay presents multiple advantages but a critical limitation: the cell number requirement, that limits drug screening on patient samples, especially in solid tumors. To solve this problem, we developed an innovative microfluidic-based DBP (µDBP) device that overcomes tissue limitations on primary samples. We used microfluidic chips to generate a gradient of BIM BH3 peptide, compared it with the standard flow cytometry based DBP, and tested different anticancer treatments. We first examined this new technology’s predictive capacity using gastrointestinal stromal tumor (GIST) cell lines, by comparing imatinib sensitive and resistant cells, and we could detect differences in apoptotic priming and anticipate cytotoxicity. We then validated µDBP on a refractory GIST patient sample and identified that the combination of dactolisib and venetoclax increased apoptotic priming. In summary, this new technology could represent an important advance for precision medicine by providing a fast, easy-to-use and scalable microfluidic device to perform DBP in situ as a routine assay to identify the best treatment for cancer patients.Ramon y Cajal Programme, Ministerio de Economia y Competitividad grant RYC-2015–18357. (J.M.). Ministerio de Ciencia, Innovación y Universidades grant RTI2018-094533-A-I00 (J.M.). CELLEX foundation (J.M., A.M.). Beca Trienal Fundación Mari Paz Jiménez Casado (J.M.). European Research Council, grant ERC-StG-DAMOC 714317 (J.R.-A.). European Research Council, H2020 EU framework FET-open BLOC 863037 (J.R.-A.). Spanish Ministry of Economy and Competitiveness, “Severo Ochoa” Program for Centers of Excellence in R&D SEV-2020-2023 (J.R.-A.). Generalitat de Catalunya. CERCA Programme 2017-SGR-1079 (J.R.-A., J.S.). Fundación Bancaria “la Caixa”- Obra Social “la Caixa” (project IBEC-La Caixa Health Ageing) (J.R.-A.). Fero Foundation (C.S.). Networking Biomedical Research Center (CIBER). CIBER is an initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions, and the Instituto de Salud Carlos III (RD16/0006/0012), with the support of the European Regional Development Fund (J.S.)

    Resistance mechanisms and molecular epidemiology of Pseudomonas aeruginosa strains from patients with bronchiectasis

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    Non-cystic fibrosis bronchiectasis (BE) is a chronic structural lung condition that facilitates chronic colonization by different microorganisms and courses with recurrent respiratory infections and frequent exacerbations. One of the main pathogens involved in BE is Pseudomonas aeruginosa.To determine the molecular mechanisms of resistance and the molecular epidemiology of P. aeruginosa strains isolated from patients with BE.A total of 43 strains of P. aeruginosa were isolated from the sputum of BE patients. Susceptibility to the following antimicrobials was analysed: ciprofloxacin, meropenem, imipenem, amikacin, tobramycin, aztreonam, piperacillin/tazobactam, ceftazidime, ceftazidime/avibactam, ceftolozane/tazobactam, cefepime and colistin. The resistance mechanisms present in each strain were assessed by PCR, sequencing and quantitative RT-PCR. Molecular epidemiology was determined by MLST. Phylogenetic analysis was carried out using the eBURST algorithm.High levels of resistance to ciprofloxacin (44.19%) were found. Mutations in the gyrA, gyrB, parC and parE genes were detected in ciprofloxacin-resistant P. aeruginosa strains. The number of mutated QRDR genes was related to increased MIC. Different ?-lactamases were detected: blaOXA50, blaGES-2, blaIMI-2 and blaGIM-1. The aac(3)-Ia, aac(3)-Ic, aac(6?)-Ib and ant(2?)-Ia genes were associated with aminoglycoside-resistant strains. The gene expression analysis showed overproduction of the MexAB-OprM efflux system (46.5%) over the other efflux system. The most frequently detected clones were ST619, ST676, ST532 and ST109.Resistance to first-line antimicrobials recommended in BE guidelines could threaten the treatment of BE and the eradication of P. aeruginosa, contributing to chronic infection.© The Author(s) 2022. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy

    Correlating material-specific layers and magnetic distributions within onion-like Fe 3 O 4 /MnO/ γ- Mn2 O3 core/shell nanoparticles

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    This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.The magnetic responses of two nanoparticle systems comprised of Fe3 O 4/γ−Mn2O3 (soft ferrimagnetic, FM/hard FM) and Fe3O4/MnO/γ−Mn2 O3 (soft FM / antiferromagnetic, AFM/hard FM) are compared, where the MnO serves to physically decouple the FM layers. Variation in the temperature and applied field allows for Small Angle Neutron Scattering (SANS) measurements of the magnetic moments both parallel and perpendicular to an applied field. Data for the bilayer particle indicate that the graded ferrimagnetic layers are coupled and respond to the field as a single unit. For the trilayer nanoparticles, magnetometry suggests a Curie temperature (TC)≈ 40 K for the outer γ−Mn2O3 component, yet SANS reveals an increase in the magnetization associated with outer layer that is perpendicular to the applied field above TC during magnetic reversal. This result suggests that the γ−Mn2O3 magnetically reorients relative to the applied field as the temperature is increased above 40 K

    Two-, three-, and four-component magnetic multilayer onion nanoparticles based on iron oxides and manganese oxides

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    Magnetic multilayered, onion-like, heterostructured nanoparticles are interesting model systems for studying magnetic exchange coupling phenomena. In this work, we synthesized heterostructured magnetic nanoparticles composed of two, three, or four components using iron oxide seeds for the subsequent deposition of manganese oxide. The MnO layer was allowed either to passivate fully in air to form an outer layer of Mn3O4 or to oxidize partially to form MnO|Mn3O4 double layers. Through control of the degree of passivation of the seeds, particles with up to four different magnetic layers can be obtained (i.e., FeO|Fe3O4|MnO|Mn3O4). Magnetic characterization of the samples confirmed the presence of the different magnetic layers

    Electron energy-loss spectroscopic tomography of FexCo(3-x)O4 impregnated Co3O4 mesoporous particles: unraveling the chemical information in three dimensions

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    Electron energy-loss spectroscopy-spectrum image (EELS-SI) tomography is a powerful tool to investigate the three dimensional chemical configuration in nanostructures. Here, we demonstrate, for the first time, the possibility to characterize the spatial distribution of Fe and Co cations in a complex FexCo(3-x)O4/Co3O4 ordered mesoporous system. This hybrid material is relevant because of the ferrimagnetic/antiferromagnetic coupling and high surface area. We unambiguously prove that the EELS-SI tomography shows a sufficiently high resolution to simultaneously unravel the pore structure and the chemical signal
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