The accuracy of gap age estimation can be improved from 5–6 to 2 years by analyzing the annual width and carbon isotope discrimination of the rings of gap-surrounding trees.
Gap age has a direct link to the composition and structure of regeneration. However, the accuracy of gap age estimation is still limited.
We aim to improve the accuracy of gap age estimation by analyzing the width in combination with carbon isotope discrimination (∆13C) of the rings of gap-surrounding trees.
Twenty-four gap-surrounding trees (nine Ulmus laciniata, eight Fraxinus rhynchophylla, and seven Juglans mandshurica) were selected from eight artificial gaps created in December 2004. First, the growth release (i.e., peak time of percent growth change) for sample trees was measured based on the tree-ring width to identify the rough time range of gap formation. Then, the ∆13C of rings during the time range were analyzed for determining the precise year of gap formation.
The peak time of percent growth change occurred from 2005 to 2010 for U. laciniata, 2004 to 2008 for F. rhynchophylla, and 2002 to 2007 for J. mandshurica. Within the range of 2002 to 2010, the ∆13C of rings for all sample trees significantly reduced in 2005–2006 (p < 0.05), which was the estimated year of gap formation.
The introduction of ∆13C analysis could effectively reduce the estimating deviations of gap age by only considering tree-ring width analyses and finally improve the accuracy of gap age estimation within 2 years, which can provide reliable information for gap management.
Despite Klebsiella pneumoniae being widely recognized as a nosocomial pathogen, there is a critical lack in defining its reservoirs and sources of infections. Most studies on risk factors have focused on multidrug-resistant (MDR) isolates and clinically-oriented questions. Over a two-year period, we sampled 131 wild animals including mammal and bird species from three regions of Central Italy. All typical colonies isolated from the analytical portions were confirmed by real-time PCR and identified by MALDI-TOF mass spectrometry (MALDI-TOF MS). All confirmed K. pneumoniae isolates were tested for antimicrobial susceptibility to 29 antimicrobials and subjected to whole genome sequencing. Typical colonies were detected in 17 samples (13%), which were identified as K. pneumoniae (n = 16) and as K. quasipneumoniae (n = 1) by MALDI-TOF MS. The antimicrobial susceptibility profile showed that all the isolates were resistant to β-lactams (ceftobiprole, cloxacillin, cefazolin) and tetracycline; resistance to ertapenem and trimethoprim was observed and nine out of 16 K. pneumoniae isolates (56.2%) were classified as MDR. Genomic characterization allowed the detection of fluoroquinolone resistance-associated efflux pumps, fosfomycin and β-lactamase resistance genes, and virulence genes in the overall dataset. The cluster analysis of two isolates detected from wild boar with available clinical genomes showed the closest similarity. This study highlights the link between humans, domestic animals, and wildlife, showing that the current knowledge on this ecological context is lacking and that the potential health risks are underestimated.
In percutaneous pedicle screw (PPS) fixation of the osteoporotic spine, rigid screw fixation obtaining strong stabilization is important for achieving successful treatment outcomes. However, in patients with severe osteoporosis, it is difficult to obtain PPS fixation with sufficient stability. PPS fixation has potential disadvantages with respect to maintaining secure stabilization in comparison to conventional pedicle screw fixation. In PPS fixation, bone grafting to achieve posterior spine fusion is generally not applicable and transverse connectors between the rods cannot be used to reinforce the fixation. Various augmentation methods, including additional hooks, sublaminar bands, and hydroxyapatite (HA) sticks, are available for conventional pedicle screw fixation. On the other hand, there has been no established augmentation method for PPS fixation. Recently, we developed a novel augmentation technique for PPS fixation using HA granules. This technique allows the percutaneous insertion of HA granules into the screw hole along the guidewire prior to insertion of the PPS. We have used this augmentation technique for PPS fixation in various spine surgeries in patients with osteoporosis. In our previous studies, biomechanical analyses demonstrated that PPS fixation was significantly enhanced by augmentation with HA granules in the osteoporotic lumbar spine. Furthermore, augmentation with HA granules was considered to decrease the incidence of screw loosening and implant failure following PPS fixation in patients with osteoporotic spine. In this article, we describe the surgical procedures of the augmentation method using HA granules and summarize our data from the biomechanical analysis of augmentation for PPS fixation. We also review the surgical outcomes of PPS fixation with augmentation using HA granules.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：