Groin Hernia Repair during the COVID-19 Pandemic-A Romanian Nationwide Analysis.

Background and Objectives: Groin hernia repair surgery (GHRS) is among the most common elective interventions. The aim of this three-year nationwide study on GHRS is to provide a thorough analysis of the impact that the COVID-19 pandemic had on the Romanian Health System in regard to elective procedures. Materials and Methods: 46,795 groin hernia cases obtained between 2019 and 2021 from the DRG database using ICD-10 diagnostic codes. The data were collected from all 261 GHRS performing hospitals nationwide, including 227 public hospitals (PbH) and 34 private hospitals (PvH). The 42 variables taken into account were processed using Microsoft Excel 2021, applying Chi square, F-Test Two-Sample for variances, and Two Sample t-Test. The significance threshold considered was p < 0.001. Results: Of the grand total of cases, 96.2% were inguinal hernias, 86.8% were performed on men, 15.2% were laparoscopic procedures, and 6.88% were in PvH. Overall, due to the pandemic, the total number of GHRS decreased with 44.45% in 2020 and with 29.72% in 2021 compared to pre-pandemic year 2019. April 2020 shows the steepest decrease in GHRS (91 procedures nationwide). In the private sector, there was an opposite trend with increases in the number of cases by 12.21% and a 70.22% in both pandemic years. The mean admission period (MAP) for all procedures was 5.5 days. There was a significant difference between PbH and PvH (5.75 vs. 2.8 days, p < 0.0001). During the pandemic, the MAP in PbH decreased (6.02 in 2019, 5.82 in 2020 and 5.3 in 2021), remaining stable for PvH (2.9 days in 2019, 2.85 days in 2020 and 2.74 days in 2021). Conclusions: The COVID-19 pandemic significantly reduced the overall number of GHRS performed in Romania in 2020 and 2021, compared to 2019. However, the private sector thrived with an actual increase in the number of cases. There was a significant lower MAP in the PvH compared to PbH throughout the three-year period.

Size-dependent redox behavior of iron observed by in-situ single nanoparticle spectro-microscopy on well-defined model systems.

Understanding the chemistry of nanoparticles is crucial in many applications. Their synthesis in a controlled manner and their characterization at the single particle level is essential to gain deeper insight into chemical mechanisms. In this work, single nanoparticle spectro-microscopy with top-down nanofabrication is demonstrated to study individual iron nanoparticles of nine different lateral dimensions from 80 nm down to 6 nm. The particles are probed simultaneously, under same conditions, during in-situ redox reaction using X-ray photoemission electron microscopy elucidating the size effect during the early stage of oxidation, yielding time-dependent evolution of iron oxides and the mechanism for the inter-conversion of oxides in nanoparticles. Fabrication of well-defined system followed by visualization and investigation of singled-out particles eliminates the ambiguities emerging from dispersed nanoparticles and reveals a significant increase in the initial rate of oxidation with decreasing size, but the reactivity per active site basis and the intrinsic chemical properties in the particles remain the same in the scale of interest. This advance of nanopatterning together with spatially-resolved single nanoparticle X-ray absorption spectroscopy will guide future discourse in understanding the impact of confinement of metal nanoparticles and pave way to solve fundamental questions in material science, chemical physics, magnetism, nanomedicine and nanocatalysis.

Direct observation of magnetic metastability in individual iron nanoparticles.

X-ray photoemission electron microscopy combined with x-ray magnetic circular dichroism is used to study the magnetic properties of individual iron nanoparticles with sizes ranging from 20 down to 8 nm. While the magnetocrystalline anisotropy of bulk iron suggests superparamagnetic behavior in this size range, ferromagnetically blocked particles are also found at all sizes. Spontaneous transitions from the blocked state to the superparamagnetic state are observed in single particles and suggest that the enhanced magnetic energy barriers in the ferromagnetic particles are due to metastable, structurally excited states with unexpected life times.