Volumetry after botulinum toxin A: the impact on abdominal wall compliance and endotracheal pressure.

PURPOSE: Botulinum toxin type A (BTA) is an adjuvant tool used in the preoperative optimization of complex hernias before abdominal wall reconstruction (AWR). This study aims to investigate changes in the abdominal cavity and hernia sac dimensions after BTA application. METHOD: A prospective study with 27 patients with a hernia defect of ≥ 10 cm and loss of domain (LOD) ≥ 20% underwent AWR. Computed tomography (CT) measurements and volumetry before and after the application of BTA were performed. Intraoperative and postoperative outcomes were evaluated. RESULTS: Imaging post-BTA revealed hernia width reduction of 1.9 cm (p = 0.002), lateral abdominal wall muscle elongation of 3.1 cm (p < 0.001), hernia volume reduction (HV) from 2.9 ± 0.9L to 2.4 ± 0.8L (p < 0.001), increase in abdominal cavity volume (ACV) from 9.7 ± 2.5L to 10.3L ± 2.4L (p = 0.003), and a reduction in the HV/ACV ratio from 30.2 ± 5% to 23.4 ± 6% (p < 0.001). Fascial closure was achieved in 92.6% of cases and component separation was required in 78%. The average variation in pulmonary plateau pressure was 3.53 cmH2O, and there were no postoperative respiratory failure recorded. At the 90-day follow-up, the wound morbidity rate was 25%, unplanned readmissions were 11%, and hernia recurrence 7.4%. CONCLUSION: BTA produces measurable volumetric changes in abdominal wall and appears to facilitate fascial closure. Further studies are required to determine the role of BTA in the surgical armamentarium for complex hernia repair.

Intralayer and interlayer electron-phonon interactions in twisted graphene heterostructures.

The understanding of interactions between electrons and phonons in atomically thin heterostructures is crucial for the engineering of novel two-dimensional devices. Electron-phonon (el-ph) interactions in layered materials can occur involving electrons in the same layer or in different layers. Here we report on the possibility of distinguishing intralayer and interlayer el-ph interactions in samples of twisted bilayer graphene and of probing the intralayer process in graphene/h-BN by using Raman spectroscopy. In the intralayer process, the el-ph scattering occurs in a single graphene layer and the other layer (graphene or h-BN) imposes a periodic potential that backscatters the excited electron, whereas for the interlayer process the el-ph scattering occurs between states in the Dirac cones of adjacent graphene layers. Our methodology of using Raman spectroscopy to probe different types of el-ph interactions can be extended to study any kind of graphene-based heterostructure.

Edge phonons in black phosphorus.

Black phosphorus has recently emerged as a new layered crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and behaviour of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.

Randomised comparison of the efficacy and safety of a novelDES with biodegradable polymer and cobalt-chromium alloy -Inspiron I trial

Aims: The efficacy of a novel drug eluting stents with biodegradable polymer andcobalt-chromium alloy should be tested in the context of randomised trials, evenwhen using drugs known to be effective, such as sirolimus. The objective of thepresent study was to evaluate the safety and efficacy of a novel formulation of asirolimus-eluting stent with biodegradable polymer and cobalt-chromium alloyagainst a stent with the same metallic structure but without polymer coating or drugelution.Methods and results: The INSPIRON-I trial is a multicenter 2-arm randomisedtrial, conducted in 4 Brazilian institutions, which included 58 patients allocated forthe Inspiron sirolimus-eluting stent or the Cronus bare metal stent in a 2:1 ratio.Patients had de novo coronary lesions in native vessels with a diameter between2.5 and 3.5 mm, amenable for treatment with a single stent of 19 mm or less in length. The primary objective was to compare the in-stent late loss at 6 months of the sirolimus-eluting versus the control bare metal stent. Important secondary objectives included the comparison of major adverse cardiac events (MACE) ofdeath, myocardial infarction and target lesion revascularisation at 12 months. The study randomised 58 patients, 39 in the Inspiron group and 19 in the Cronusgroup. The great majority of the patients included had stable angina (76%).Baseline clinical and angiographic characteristics from both groups were similar, and 55.6% of the lesions were B2/C. The angiographic restudy at 6 months showed that percent diameter stenosis was significantly lower in the Inspiron group (15.8% vs. 38.7%, respectively; p=0.03), as well as late lumen loss (0.18 vs. 0.67 mm; p=0.009). Binary restenosis was also lower for Inspiron group, but without statistical difference (p=0.42)...

Phonon-assisted excitonic recombination channels observed in DNA-wrapped carbon nanotubes using photoluminescence spectroscopy.

By using a sample of DNA-wrapped single-wall carbon nanotubes strongly enriched in the (6,5) nanotube, photoluminescence emissions observed at special excitation energy values were identified with specific mechanisms of phonon-assisted excitonic absorption and recombination processes associated with (6,5) nanotubes, including one-phonon, two-phonon, and some continuous-luminescence processes. Such detailed processes are not separately identified in three-dimensional semiconducting materials. A general theoretical framework is presented to interpret the experimentally observed phonon-assisted processes in terms of excitonic states.