A Superconductor Made by a Metal Heterostructure at the Atomic Limit Tuned at the "Shape Resonance": MgB2

We have studied the variation of Tc with charge density and lattice parameters in Mg1-xAlxB2 superconducting samples at low Al doping x<8%. We show that high Tc occurs where the chemical potential is tuned at a "superconducting shape resonance" near the energy Ec of the quantum critical point (QCP) for the dimensional transition from 2D to 3D electronic structure in a particular subband of the natural superlattice of metallic atomic boron layers. At the "shape resonance" the electrons pairs see a 2D Fermi surface at EF-w0 and a 3D Fermi surface at EF+wo, where wo is the energy cut off of the pairing interaction. The resonant amplification occurs in a narrow energy range where EF-Ec is in the range of 2wo.Comment: 16 page

High Tc superconductivity at a critical strain and charge density in diborides

We report variation of lattice structure in diborides (AB2) with different A atoms to identify the special case of MgB2 showing high Tc superconductivity. High purity MgB2 (Tc~39 K) has been prepared by direct reaction of the elements and the lattice parameters are measured by x-ray diffraction determining the strain e of the B-B distance. The results show that the superconductivity in these intermetallics appear near a critical point in a two variables (strain and charge density) phase diagram at (ec, rc).Comment: 10 page

Double-vergent orogenesis in north Patagonia: different mechanisms of Andean deformation

The Andes constitute an ideal tectonic setting for investigating different modes of subduction orogeny,given its segmented anatomy and the potential drivers of the upper/lower plates over the episodicperiods of mountain building (e.g., Mpodozis and Ramos, 1989). In this sense, integrated analyses oforogenic sections that contemplate from the fore to retroarc sections and their potential coupling are stilllacking. Therefore, we studied a forearc segment in northern Patagonia (~41-44ºS) in order to analyzeits crustal architecture and the structural control over the thick-infilling oceanic forearc basins andNeogene strata in the western Andean slope and Coastal Cordillera. Here, Neogene strata weredeposited during the tectonic switching from an accentuated late Oligocene-early Miocene extensionalregime to a mid-late Miocene contractional period and the breakup of the Farallon into the Nazca plate(e.g., Jordan et al., 2001). We performed a structural analysis through field work along with acquisitionof several seismic data (2D multichannel and refraction seismic data and drillholes from ENAP-Chile) inorder to identify the time of activity of the main forearc structures and their relation, in a crustal scale,with the east-vergence faults that form the retroarc fold-thrust belt. Our data reveal the presence of amajor west-vergent thrust in the western slope of the Andean cordillera and a trenchward directed splayin the Coastal Cordillera during mid-late Miocene time, contemporaneously with retroarc fold-thrust beltgrowth (e.g., Folguera et al., 2018). This suggests a double-vergent orogenesis for this Andeansegment, and proposes a discussion on the general modes of Andean deformation like in othersegments of the Central Andes (e.g., Riesner et al., 2018).Fil: Echaurren Gonzalez, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Encinas, Alfonso. Universidad de Concepción; ChileFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Gianni, Guido Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Zambrano, P.. Universidad Andrés Bello; ChileFil: Duhart, P.. Servicio Nacional de Geologia y Mineria (SERNAGEOMIN); Chile8th International Symposium on Andean GeodynamicsEcuadorEscuela Politécnica NacionalFrench Institut de Recherche pour le Développemen

Racial Health Disparity and COVID-19

Abstract: The infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and resultant coronavirus diseases-19 (COVID-19) disproportionally affects minorities, especially African Americans (AA) compared to the Caucasian population. The AA population is disproportionally affected by COVID-19, in part, because they have high prevalence of underlying conditions such as obesity, diabetes, and hypertension, which are known to exacerbate not only kidney diseases, but also COVID-19. Further, a decreased adherence to COVID-19 guidelines among tobacco smokers could result in increased infection, inflammation, reduced immune response, and lungs damage, leading to more severe form of COVID-19. As a result of high prevalence of underlying conditions that cause kidney diseases in the AA population coupled with tobacco smoking make the AA population vulnerable to severe form of both COVID-19 and kidney diseases. In this review, we describe how tobacco smoking interact with SARS-CoV-2 and exacerbates SARS-CoV-2-induced kidney diseases including renal failure, especially in the AA population. We also explore the role of extracellular vesicles (EVs) in COVID-19 patients who smoke tobacco. EVs, which play important role in tobacco-mediated pathogenesis in infectious diseases, have also shown to be important in COVID-19 pathogenesis and organ injuries including kidney. Further, we explore the potential role of EVs in biomarker discovery and therapeutics, which may help to develop early diagnosis and treatment of tobacco-induced renal injury in COVID-19 patients, respectively. Graphical Abstract: [Figure not available: see fulltext.]