Driving up the Electrocatalytic Performance for Carbon Dioxide Conversion through Interface Tuning in Graphene Oxide-Bismuth Oxide Nanocomposites

The integration of graphene oxide (GO) into nanostructured Bi2O3 electrocatalysts for CO2 reduction (CO2RR) brings up remarkable improvements in terms of performance toward formic acid (HCOOH) production. The GO scaffold is able to facilitate electron transfers toward the active Bi2O3 phase, amending for the high metal oxide (MO) intrinsic electric resistance, resulting in activation of the CO2 with smaller overpotential. Herein, the structure of the GO-MO nanocomposite is tailored according to two synthetic protocols, giving rise to two different nanostructures, one featuring reduced GO (rGO) supporting Bi@Bi2O3 core–shell nanoparticles (NP) and the other GO supporting fully oxidized Bi2O3 NP. The two structures differentiate in terms of electrocatalytic behavior, suggesting the importance of constructing a suitable interface between the nanocarbon and the MO, as well as between MO and metal

Ultralow-temperature device dedicated to soft X-ray magnetic circular dichroism experiments

A new ultralow-temperature setup dedicated to soft X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD) experiments is described. Two experiments, performed on the DEIMOS beamline (SOLEIL synchrotron), demonstrate the outstanding performance of this new platform in terms of the lowest achievable temperature under X-ray irradiation (T = 220 mK), the precision in controlling the temperature during measurements as well as the speed of the cooling-down and warming-up procedures. Moreover, owing to the new design of the setup, the eddy-current power is strongly reduced, allowing fast scanning of the magnetic field in XMCD experiments; these performances lead to a powerful device for X-ray spectroscopies on synchrotron-radiation beamlines facilities

Direct detection of spin polarization in photoinduced charge transfer through a chiral bridge

It is well assessed that the charge transport through a chiral potential barrier can result in spin-polarized charges. The possibility of driving this process through visible photons holds tremendous potential for several aspects of quantum information science, e.g., the optical control and readout of qubits. In this context, the direct observation of this phenomenon via spin-sensitive spectroscopies is of utmost importance to establish future guidelines to control photo-driven spin selectivity in chiral structures. Here, we provide direct proof that time-resolved electron paramagnetic resonance (EPR) can be used to detect long-lived spin polarization generated by photoinduced charge transfer through a chiral bridge. We propose a system comprising CdSe quantum dots (QDs), as a donor, and C60, as an acceptor, covalently linked through a saturated oligopeptide helical bridge (χ) with a rigid structure of ∼10 Å. Time-resolved EPR spectroscopy shows that the charge transfer in our system results in a C60 radical anion, whose spin polarization maximum is observed at longer times with respect to that of the photogenerated C60 triplet state. Notably, the theoretical modelling of the EPR spectra reveals that the observed features may be compatible with chirality-induced spin selectivity, but the electronic features of the QD do not allow the unambiguous identification of the CISS effect. Nevertheless, we identify which parameters need optimization for unambiguous detection and quantification of the phenomenon. This work lays the basis for the optical generation and direct manipulation of spin polarization induced by chirality

Third-degree lesions of the external compartment of the ankle: Results of conservative treatment

Ankle sprains are one of the most common lesions of the musculoskeletal system. In some sports they are the most common reason that athletes seek medical care. For this reason many publications are dedicated to this subject, and specifically to the treatment of lesions of the external compartment, which account for about 85% of all ligamentous lesions of the ankle (O'Donoghue, 1958). The treatment of these lesions is very controversial. Some orthopedists propose early surgical treatment to restore normal healing with minimal functional lengthening. Others favor conservative treatment, while still others recommend functional treatment with the objective of accelerating the recovery of proprioceptive reflexes affected by the ligamentous lesion as well as stimulating healing by movement. The authors' diagnostic and therapeutic approach to lesions of the external compartment of the ankle is explained with special reference to lesions in athletes, who must be guaranteed perfect joint stability in order to tolerate the intense stress of sports activity without danger of relapse

Substrate mediated interaction of terbium(iii) double-deckers with the TiO2(110) surface

A terbium(iii)-bis(phthalocyaninato) neutral complex was deposited on the rutile TiO2(110) surface, and their interaction was studied by Scanning Tunneling Microscopy (STM) and X-ray Photoelectron Spectroscopy (XPS). It was found that the TiO2 rutile surface favours the adsorption of isolated molecules adopting a lying down configuration with the phthalocyanine planes tilted by about 30° when they lie in the first layer. The electronic and chemical properties of the molecules on the surface were studied by XPS as a function of the TiO2(110) substrate preparation. This study evidences that strong molecule-substrate interactions are present and a charge transfer process occurs from the molecule to the surface

Analysis of Changement de Pied, Echappe and Sissonne Ferme jumps in female ballet dancers

In classical ballet, jumping should stand more on technique and elegance rather than maximal height. This study aimed to investigate dancers’ ability to perform stable jumps with classical ballet technique. Twenty-two female dancers [divided in two groups: Expert: n=12; Novice, n=10] were recruited to perform three vertical jump protocols: 1) Changement de Pied (CHA), composed by 5 consecutive jumps; 2) Echappé (ECH), composed by two consecutive ‘Echappé’ jumps; and 3) Sissonne Fermé (SF) jumps. Through an Optojump Next system were measured: a) Height (H) of jumps; b) Jumping Point Gap (JPG) and c) Used Area (UA). The CHA analysis showed differences between consecutive jumps for JPG (p=0.003). An approach to significance (p=0.52) and a difference (p=0.42) between groups were found for H and JPG respectively, while no differences were found for UA. The ECH analysis revealed main differences between jumps for H (p<0.001), JPG (p=0.003) and UA (p<0.001), post-hoc analysis showed differences (p<0.05) between each jump from the fifth position to the second one and vice versa for H and UA whilst differences between groups emerged only for UA (p=0.001). The SF analysis showed no differences for all parameters. The results showed as in CHA dancers carried out a control on the jump height to maintain their “aplomb” and limit the medio- lateral displacement, which was also influenced by the dancers’ experience (NOV group showed higher H and JPG values). The dancers’ skill was also demonstrated by their ability to perform similar jumps in each of the two echappé cycles

Chemisorption of nitronyl-nitroxide radicals on gold surface: An assessment of morphology, exchange interaction and decoherence time

A combined Tof-SIMS, XPS and STM characterization has been performed to study the deposition of a sulphur-functionalized nitronyl nitroxide radical on Au(111) clearly demonstrating the chemisorption of intact molecules. Continuous -wave EPR characterization showed that the radical molecules maintain their paramagnetic character. Pulsed EPR measurements allowed to determine the decoherence time of the nanostructure at 80 K, which turned out to be comparable to the one measured in frozen solution and longer than previously reported for many radicals and other paramagnetic molecules at much lower temperatures. Furthermore, we conducted a state-of-the-art ab initio molecular dynamics study, suggesting different possible scenarios for chemisorption geometries and predicting the energetically favoured geometry. Calculation of the magnetic properties indicates a partial non-innocent role of the gold surface in determining the magnetic interactions between radicals in packed structures. This suggests that the observed EPR spectrum is to be attributed to low-density domains of disordered radicals interacting via dipolar interactions