Vegetation resilience assessment and its climatic driving factors: Evidence from surface coal mines in northern China.

Vegetation resilience is a key concept for understanding ecosystem responses to disturbances and is essential for maintaining ecosystem sustainability. However, assessing vegetation resilience remains challenging, especially for areas with significant disturbances and ecological restoration, such as surface coal mine ecosystems. Vegetation resilience assessment requires a combination of disturbance magnitude, recovery magnitude, and recovery time. In this study, we propose a vegetation resilience assessment method by integrating disturbance magnitude, recovery magnitude and recovery time. Forty-six surface coal mines in northern China were analysed as the study areas. A geographical detector model was used to explore the influence of climatic factors on vegetation resilience. The results indicated that the vegetation resilience curves included three shapes, inverted U-shaped, S-shaped, and monotonically decreasing, and the different disturbance-recovery relationships of the curves indicated that natural and social factors jointly changed the ecological restoration process. The vegetation resilience of the 46 surface coal mines varies widely, ranging from 0.87 to 7.22, showing a spatial decreasing trend from east to west. The explanatory power of different climatic factors on vegetation resilience by indirectly affecting hydrothermal conditions varies, with the effect of atmospheric pressure being the most significant and the superposition of the two climatic factors enhancing the effect on vegetation resilience. This study enriches the understanding of vegetation resilience assessment and provides important information to guide the differentiation of ecological restoration and resource development of surface coal mines in different regions.

Surgical outcomes of percutaneous endoscopic thoracic decompression in the treatment of multi-segment thoracic ossification of the ligamentum flavum.

BACKGROUND: Previous studies have demonstrated satisfactory outcomes of percutaneous endoscopic thoracic decompression (PETD) for single-segment thoracic ossification of the ligamentum flavum (TOLF). However, the clinical outcomes of PETD in patients with multi-segment TOLF (mTOLF) remain unclear. The aim of the present study was to evaluate the efficacy and safety of PETD for patients with multi-segment mTOLF. METHODS: Eighteen consecutive patients (41 segments) with mTOLF were treated with PETD between January 2020 and December 2021. The clinical outcomes were evaluated using the modified Japanese Orthopaedic Association (mJOA) score and Visual Analog Scale (VAS), whereas radiographic parameters were measured by cross-section area of the spinal canal and anteroposterior diameter of the spinal cord. RESULTS: The follow-up period ranged from 14 to 34 months. The mean operation time and blood loss were 154.06 ± 32.14 min and 61.72 ± 12.72 ml, respectively. Hospital stay after first-stage operation was 10.89 ± 2.42 days. The mJOA score and VAS score significantly improved at the final follow-up, with a mean mJOA recovery rate of 63.3 ± 21.90%. The incidence of complications was 12.2% per level. The radiographic outcomes showed adequate decompression of the spinal cord. CONCLUSIONS: The present study demonstrates that PETD is effective and safe as a minimally invasive procedure to treat patients with mTOLF. All patients showed relief of their symptoms and improvement in neurological function.

Clinical Efficacy of Endoscopic-Assisted Resection of Single-Segment Ossification of the Posterior Longitudinal Ligament in the Treatment of Thoracic Spinal Stenosis.

Objective: To explore the clinical efficacy, characteristics and safety of endoscopic-assisted resection of single-segment posterior longitudinal ligament ossification in the treatment of thoracic spinal stenosis (TSS). Method: Fifteen TSS patients, including 6 males and 9 females aged 43-70 years treated with endoscopic-assisted resection of single-segment posterior longitudinal ligament ossification through the transfacet joint approach by our team from November 2016 to June 2020 were retrospectively analyzed. The operation time, intraoperative blood loss, and postoperative complications were recorded. The VAS score, ODI and JOA score (full score, 11 points) were recorded before the operation, after the operation and at the last follow-up to evaluate the clinical efficacy and calculate the improvement rate. Results: The ventral side of the spinal cord was decompressed in all patients, providing improvements in neurological symptoms and significant pain relief. The mean follow-up time was 20.27 ± 3.87 months. Mean operation time, intraoperative blood loss, and hospitalization time were found to be 84.80 ± 13.23 min, 36.33 ± 7.41 mL, 5.13 ± 1.02 days; respectively.The JOA score at the last follow-up was 8.6 ± 1.25, which was significantly better than the preoperative (5.53 ± 1.20) and postoperative (6.87 ± 1.31) scores (p < 0.05). The mean JOA score improvement rate was 56.5 ± 18.00%. The JOA score improvement rate classification at the last follow-up was excellent in 3 cases, good in 8 cases, effective in 3 cases, and no change in 1 case; for an effective rate of 93.33%. The VAS score significantly decreased from 6.67 ± 1.01 preoperatively to 3.47 ± 0.88 postoperatively and 1.73 ± 0.67 at the last follow-up (p < 0.05). The ODI significantly decreased from 72.07 ± 6.08 preoperatively to 45.93 ± 5.01 postoperatively and 12.53 ± 2.33 at the last follow-up (p < 0.05). Dural rupture occurred in 2 patients during the operation; 1 patient experienced neck discomfort during the operation, which was considered to be caused by high fluid pressure and was relieved by massage and by lowering the height of the irrigation fluid. No cases of cerebrospinal fluid leakage, wound infection or other complications occurred. Conclusion: Endoscopic-assisted resection of posterior longitudinal ligament ossification through the facet joint approach is a safe and effective method for the treatment of TSS.