Every year, a committee of experts sits down with a tough job to do: from among all ICREA publications, they must find a handful that stand out from all the others. This is indeed a challenge. The debates are sometimes heated and always difficult but, in the end, a shortlist of the most outstanding publications of the year is produced. No prize is awarded, and the only additional acknowledge is the honour of being chosen and highlighted by ICREA. Each piece has something unique about it, whether it be a particularly elegant solution, the huge impact it has in the media or the sheer fascination it generates as a truly new idea. For whatever the reason, these are the best of the best and, as such, we are proud to share them here.
LIST OF SCIENTIFIC HIGHLIGHTS
The health impacts and pathways of gentrification in European and American cities.
(2021)
The health impacts and pathways of gentrification in European and American cities.
As global cities grapple with the increasing challenge of gentrification and displacement, research in public health and urban geography has presented growing evidence about the negative impacts of those unequal urban changes on the health of historically marginalized groups. Yet, to date comprehensive research about the variety of health impacts and their pathways beyond single case sites and through an international comparative approach of different gentrification drivers and manifestations remains scarce. Our paper analyzes qualitative data on the pathways by which gentrification impacts the health of historically marginalized residents in 14 cities in Europe and North America. We build on 77 interviews with key neighborhood stakeholders. Data analysis indicates four main concurrent processes: Threats to housing and financial security; Socio-cultural displacement; Loss of services and amenities through institutional gentrification; and Increased risks of criminal behavior and compromised public safety. Gentrification is experienced as a chain of physical and emotional community and individual traumas – an overall shock for historically marginalized groups – because of permanent pressures of insecurity, loss, state of displaceability, and the associated exacerbation of socio-environmental disadvantages.
Single-Atom Catalysts for Energy and Environmental Applications
(2021)
Single-Atom Catalysts for Energy and Environmental Applications
Single-atom catalysts (SACs), thanks to the higher density of exposed catalytic sites, can provide high selectivity and and efficiency as well as the suppression of the competing reactions. We have explored different SACs based on Fe,[1] Ni [2] and a combination of both [3].
First of all, we proposed the use of a C2N framework (a carbon nitride-based 2D layered nanostructure) loaded with atomically and uniformly dispersed iron (Fe/C2N) as a host material for the sulfur in a lithium-sulfur battery cathode.[1] C2N shows excellent electrical conductivity and is a highly porous and high surface area framework. The iron atoms trapped in the pores improve the ability of the cathode material to immobilize the soluble polysulfides and promote the reaction kinetics between sulfur, polysulfides and lithium sulfide.
Secondly, we tuned the electronic environment of atomically dispersed Ni-based 2D organic framework catalyst through the modification of their edge coordination toward alcohol electrooxidation.[2] We demonstrated that such nickel-based organic frameworks, combined with carbon nanotubes, exhibit outstanding catalytic activity and durability toward the oxidation of methanol, ethanol, and benzyl alcohol. The work not only introduced a new atomically dispersed Ni-based catalyst, but also demonstrates a new strategy for designing and engineering high-performance catalysts through the tuning of their chemical environment.
Finally, we designed a new double-metal catalyst, presenting nearby nickel and iron active sites, which improved both efficiency and selectivity of the carbon dioxide (CO2) reduction reaction.[3] This configuration, provides excellent selectivity to CO2 evolution, boosting absorption and desorption of intermediates in the reduction process, and guarantees a low overpotential, which leads to less energy consumption. In addition, undesired competing reactions are strongly limited. Furthermore, the combination of Ni and Fe active sites demonstrated to act as a nano-reactor, since multistep reactions take place simultaneously with an improved overall activity and selectivity.
Children are less efficient at trasmitting SARS-CoV-2 than adults
(2021)
Children are less efficient at trasmitting SARS-CoV-2 than adults
In this article, we analyzed contagions of coronavirus disease 2019 inside school bubble groups in Catalonia, Spain, in the presence of strong nonpharmaceutical interventions from September to December 2020. More than 1 million students were organized in bubble groups and monitored and analyzed by the Health and the Educational departments.
We had access to 2 data sources, and both were employed for the analysis, one is the Catalan school surveillance system and the other of the educational department. As soon as a positive index case is detected by the health system, isolation is required for all members of the bubble group, in addition to a mandatory proactive systematic screening of each individual. All infected cases are reported. It permits the calculation of the average reproductive number (R*), corresponding to the average number of infected individuals per index case.
We found that propagation inside of the bubble group was small. Among 75% index cases, there was no transmission to other members in the classroom, with an average R* across all ages inside the bubble of R* = 0.4.
We found a significant age trend in the secondary attack rates, with the R* going from 0.2 in preschool to 0.6 in high school youth.
We concluded that he secondary attack rate depends on the school level and therefore on the age. Super-spreading events (outbreaks of 5 cases or more) in childhood were rare, only occurring in 2.5% of all infections triggered from a pediatric index case.
This work, together with other research conducted in children from Catalonia (KIDS-Corona project), had important implications in the recommendations that we were able to make to the Ministeries of Education and Health for a safe return to school by Spanish children.
Indeed, Spain reopened their schools in September 2020, and has never closed them subsequently, something that not many other countries have been able to do. Transmission within schools has been kept to a minimum, and much of the merit was made on the design -evidence-based- of preventive recommendations tailored to children.
Most brilliant and broad laser light source
(2021)
In a recent study published in Nature Photonics, the team of ICREA Prof. Biegert at ICFO reports on a compact high-brightness mid-IR-driven source combining a gas-filled anti-resonant-ring photonic crystal fiber with a novel nonlinear-crystal. The table top source provides a seven-octave coherent spectrum from 340 nm to 40,000 nm with spectral brightness 2-5 orders of magnitude higher than one of the brightest Synchrotron facilities.
Published in Nature Communications, a collaborative theoretical study led by Prof. Stefan Bromley shows how to reversibly switch between closed-shell and open-shell states in radical-based 2D organic materials. The work was featured as an Editor’s Highlight (www.nature.com/collections/eecgdgijhh).
Since the discovery of graphene, a number of inorganic 2D materials with a range of physical and chemical properties have been synthesized by top-down approaches. Such materials possess very high in-plane tensile strengths, which only allow for moderate strains generating modest electronic changes. In parallel, chemists have developed bottom-up synthesis approaches to produce 2D covalent organic frameworks (2D-COFs) based on linking arrays of molecular building blocks. Here the authors show that a particular family of 2D-COFs may provide an ideal basis for highly sensitive strain-control of electronic properties. Using persistent radicals as building blocks for new two-dimensional covalent organic radical frameworks (2D-CORFs) promises to provide a platform for new flexible materials in which optical, magnetic and electrical properties can be reversibly controlled by modest structural strain.
In this work, the effect of uniaxial in-plane strain on a series of 2D covalent organic radical frameworks (2D-CORFs) is studied by means of density functional theory (DFT) based calculations. The results demonstrate that uniaxial in-plane tensile strains may be used to efficiently switch between antiferromagnetic multi-radical (i.e. open-shell) and diamagnetic quinoidal (i.e. closed-shell) states in a reversible manner. In addition, the authors demonstrate that the strain-induced electronic switching is robust at finite temperatures, which is a prerequisite for experimental viability, and thus technological applicability. Overall, their work shows that integrating bi-radical moieties into covalent 2D materials is a promising route to achieve macroscopic control over molecular-scale electronic states.
The interactions among species are crucial for structuring lake fish communities
The contribution of species interactions such as predation, competition and facilitation to forming local communities is an intensely discussed topic in ecological research. A major methodological challenge is to disentangle the effects of geographical and abiotic predictors from those caused by species interactions.
In this study we applied a model-based approach on fish community composition in 772 European lakes, to find empirical evidence for contributions of species interactions to fish community composition. Our study reveals that positive and negative interactions between species are contributing substantially to the structuring of fish communities in European lakes, in addition to environmental filters and dispersal limitation.
