The recent development in the fabrication of artificial oxide heterostructures opens new avenues in the field of quantum materials by enabling the manipulation of the charge, spin and orbital degrees ...of freedom. In this context, the discovery of two-dimensional electron gases (2-DEGs) at LaAlO3/SrTiO3 interfaces, which exhibit both superconductivity and strong Rashba spin-orbit coupling (SOC), represents a major breakthrough. Here, we report on the realisation of a field-effect LaAlO3/SrTiO3 device, whose physical properties, including superconductivity and SOC, can be tuned over a wide range by a top-gate voltage. We derive a phase diagram, which emphasises a field-effect-induced superconductor-to-insulator quantum phase transition. Magneto-transport measurements show that the Rashba coupling constant increases linearly with the interfacial electric field. Our results pave the way for the realisation of mesoscopic devices, where these two properties can be manipulated on a local scale by means of top-gates.
A resolutive therapy for Duchene muscular dystrophy, a severe degenerative disease of the skeletal muscle, is still lacking. Because autophagy has been shown to be crucial in clearing dysfunctional ...organelles and in preventing tissue damage, we investigated its pathogenic role and its suitability as a target for new therapeutic interventions in Duchenne muscular dystrophy (DMD). Here we demonstrate that autophagy is severely impaired in muscles from patients affected by DMD and mdx mice, a model of the disease, with accumulation of damaged organelles. The defect in autophagy was accompanied by persistent activation via phosphorylation of Akt, mammalian target of rapamycin (mTOR) and of the autophagy-inhibiting pathways dependent on them, including the translation-initiation factor 4E-binding protein 1 and the ribosomal protein S6, and downregulation of the autophagy-inducing genes LC3, Atg12, Gabarapl1 and Bnip3. The defective autophagy was rescued in mdx mice by long-term exposure to a low-protein diet. The treatment led to normalisation of Akt and mTOR signalling; it also reduced significantly muscle inflammation, fibrosis and myofibre damage, leading to recovery of muscle function. This study highlights novel pathogenic aspects of DMD and suggests autophagy as a new effective therapeutic target. The treatment we propose can be safely applied and immediately tested for efficacy in humans.
Relative humidity is simultaneously a sensing target and a contaminant in gas and volatile organic compound (VOC) sensing systems, where strategies to control humidity interference are required. An ...unmet challenge is the creation of gas‐sensitive materials where the response to humidity is controlled by the material itself. Here, humidity effects are controlled through the design of gelatin formulations in ionic liquids without and with liquid crystals as electrical and optical sensors, respectively. In this design, the anions DCA− and Cl− of room temperature ionic liquids from the 1‐butyl‐3‐methylimidazolium family tailor the response to humidity and, subsequently, sensing of VOCs in dry and humid conditions. Due to the combined effect of the materials formulations and sensing mechanisms, changing the anion from DCA− to the much more hygroscopic Cl−, leads to stronger electrical responses and much weaker optical responses to humidity. Thus, either humidity sensors or humidity‐tolerant VOC sensors that do not require sample preconditioning or signal processing to correct humidity impact are obtained. With the wide spread of 3D‐ and 4D‐printing and intelligent devices, the monitoring and tuning of humidity in sustainable biobased materials offers excellent opportunities in e‐nose sensing arrays and wearable devices compatible with operation at room conditions.
Humidity influence in sensing of volatile organic compounds is tuned by materials design. The anions of ionic liquids tailor the gas sensing material's sensitivity to humidity, yielding either humidity‐sensitive or humidity‐tolerant odorant sensors that do not require sample preconditioning or signal processing to correct humidity impact, thereby contributing to the widespread field of artificial olfaction.
Abstract
In LaTiO
3
/SrTiO
3
and LaAlO
3
/SrTiO
3
heterostructures, the bending of the SrTiO
3
conduction band at the interface forms a quantum well that contains a superconducting two-dimensional ...electron gas (2-DEG). Its carrier density and electronic properties, such as superconductivity and Rashba spin-orbit coupling can be controlled by electrostatic gating. In this article we show that the Fermi energy lies intrinsically near the top of the quantum well. Beyond a filling threshold, electrons added by electrostatic gating escape from the well, hence limiting the possibility to reach a highly-doped regime. This leads to an irreversible doping regime where all the electronic properties of the 2-DEG, such as its resistivity and its superconducting transition temperature, saturate. The escape mechanism can be described by the simple analytical model we propose.
The aim of the present study was to investigate the utility of the modified frailty index (mFI) to predict outcomes in patients who underwent cardiac resynchronization therapy (CRT) device ...implantation. A retrospective cohort study of patients undergoing CRT implantation or upgrade over a 5-year period was performed. The relation between the preprocedural 11-component mFI and clinical outcomes including 1-year mortality, periprocedural and 30-day adverse events, 30-day readmission, length of hospitalization after procedure, and response to CRT defined by changes in left ventricular ejection fraction and end-diastolic volume were studied. Of 283 patients studied, 134 (47.3%) were classified as frail (mFI ≥3). Frailty was associated with an increased risk of 1-year mortality (hazard ratio 5.87, p = 0.033 in multivariate analysis), and increased frequency of adverse events (p = 0.013), 30-day readmission (p = 0.0077), and postprocedural length of stay ≥3 days (p = 0.0005). Frail patients had significantly less echocardiographic response to CRT compared with nonfrail patients with change in left ventricular ejection fraction 6% versus 12% (p = 0.004) and change in left ventricular end-diastolic volume −19.9 versus −43.3 ml (p = 0.006). In conclusion, frailty as assessed by the mFI is associated with an increase in 1-year mortality, adverse events, 30-day readmission, length of stay, and poorer response to CRT after implantation.
Abstract Herbivorous insects alter biogeochemical cycling within forests, but the magnitude of these impacts, their global variation, and drivers of this variation remain poorly understood. To ...address this knowledge gap and help improve biogeochemical models, we established a global network of 74 plots within 40 mature, undisturbed broadleaved forests. We analyzed freshly senesced and green leaves for carbon, nitrogen, phosphorus and silica concentrations, foliar production and herbivory, and stand-level nutrient fluxes. We show more nutrient release by insect herbivores at non-outbreak levels in tropical forests than temperate and boreal forests, that these fluxes increase strongly with mean annual temperature, and that they exceed atmospheric deposition inputs in some localities. Thus, background levels of insect herbivory are sufficiently large to both alter ecosystem element cycling and influence terrestrial carbon cycling. Further, climate can affect interactions between natural populations of plants and herbivores with important consequences for global biogeochemical cycles across broadleaved forests.
The term tunnel electroresistance (TER) denotes a fast, non-volatile, reversible resistance switching triggered by voltage pulses in ferroelectric tunnel junctions. It is explained by subtle ...mechanisms connected to the voltage-induced reversal of the ferroelectric polarization. Here we demonstrate that effects functionally indistinguishable from the TER can be produced in a simpler junction scheme-a direct contact between a metal and an oxide-through a different mechanism: a reversible redox reaction that modifies the oxide's ground-state. This is shown in junctions based on a cuprate superconductor, whose ground-state is sensitive to the oxygen stoichiometry and can be tracked in operando via changes in the conductance spectra. Furthermore, we find that electrochemistry is the governing mechanism even if a ferroelectric is placed between the metal and the oxide. Finally, we extend the concept of electroresistance to the tunnelling of superconducting quasiparticles, for which the switching effects are much stronger than for normal electrons. Besides providing crucial understanding, our results provide a basis for non-volatile Josephson memory devices.
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