Efficacy of local infiltration analgesia on recovery after total hip arthroplasty using direct anterior approach under spinal anaesthesia: a randomized, double-blind, placebo-controlled trial.

The utilization of local infiltration analgesia (LIA) is a common practice in total hip arthroplasty (THA) procedures to mitigate postoperative pain and diminish the necessity for opioids. However, contemporary literature reports conflicting results. Our working hypothesis was that LIA renders better postoperative VAS-scores and reduces the need for oral analgetics. We performed a randomized, double-blind, placebo-controlled trial aimed at examining the effectiveness of LIA in THA. A total of 90 patients were included for statistical analysis. Our primary endpoint was the Visual Analogue Scale, VAS, (0: no pain, 10: unbearable pain) preoperatively, at the 1st, 2nd, 3rd, 4th and 12th hour postoperative intervals and at discharge. Our secondary endpoints included the postoperative opioid consumption, as well as patient satisfaction at 2 and 6 weeks postoperatively, measured using the Numeric Rating Scale, NRS. LIA has a tendency for superior results regarding VAS- Scores at 3 and 4 hours postoperatively. There were no notable statistical distinctions observed in terms of patients necessitating rescue opioid consumption. Patient satisfaction using the NRS at both the 2-week and 6-week postoperatively did not differ significantly between both groups. The administration of LIA could offer advantages during the initial stages of postoperative recovery, which could be particularly valuable in rapid recovery programs.

Lifetime-enhanced transport in silicon due to spin and valley blockade.

We report the observation of lifetime-enhanced transport (LET) based on perpendicular valleys in silicon by transport spectroscopy measurements of a two-electron system in a silicon transistor. The LET is manifested as a peculiar current step in the stability diagram due to a forbidden transition between an excited state and any of the lower energy states due to perpendicular valley (and spin) configurations, offering an additional current path. By employing a detailed temperature dependence study in combination with a rate equation model, we estimate the lifetime of this particular state to exceed 48 ns. The two-electron spin-valley configurations of all relevant confined quantum states in our device were obtained by a large-scale atomistic tight-binding simulation. The LET acts as a signature of the complicated valley physics in silicon: a feature that becomes increasingly important in silicon quantum devices.

Tunable Kondo effect in a single donor atom.

The Kondo effect has been observed in a single gate-tunable atom. The measurement device consists of a single As dopant incorporated in a silicon nanostructure. The atomic orbitals of the dopant are tunable by the gate electric field. When they are tuned such that the ground state of the atomic system becomes a (nearly) degenerate superposition of two of the silicon valleys, an exotic and hitherto unobserved valley Kondo effect appears. Together with the "regular" spin Kondo, the tunable valley Kondo effect allows for reversible electrical control over the symmetry of the Kondo ground state from an SU(2) to an SU(4) configuration.

Transport spectroscopy of a single dopant in a gated silicon nanowire.

We report on spectroscopy of a single dopant atom in silicon by resonant tunneling between source and drain of a gated nanowire etched from silicon on insulator. The electronic states of this dopant isolated in the channel appear as resonances in the low temperature conductance at energies below the conduction band edge. We observe the two possible charge states successively occupied by spin-up and spin-down electrons under magnetic field. The first resonance is consistent with the binding energy of the neutral D0 state of an arsenic donor. The second resonance shows a reduced charging energy due to the electrostatic coupling of the charged D- state with electrodes. Excited states and Zeeman splitting under magnetic field present large energies potentially useful to build atomic scale devices.