Biomechanical analysis of adjacent segments after correction surgery for adult idiopathic scoliosis: a finite element analysis.

The biomechanical aspects of adjacent segment degeneration after Adult Idiopathic Scoliosis (AdIS) corrective surgery involving postoperative changes in motion and stress of adjacent segments have yet to be investigated. The objective of this study was to evaluate the biomechanical effects of corrective surgery on adjacent segments in adult idiopathic scoliosis by finite element analysis. Based on computed tomography data of the consecutive spine from T1-S1 of a 28-year-old male patient with adult idiopathic scoliosis, a three-dimensional finite element model was established to simulate the biomechanics. Two posterior long-segment fixation and fusion operations were designed: Strategy A, pedicle screws implanted in all segments of both sides, and Strategy B, alternate screws instrumentation on both sides. The range of motion (ROM), Maximum von Mises stress value of intervertebral disc (IVD), and Maximum von Mises stress of the facet joint (FJ) at the fixation adjacent segment were calculated and compared with data of the preoperative AdIS model. Corrective surgery decreased the IVD on the adjacent segments, increased the FJ on the adjacent segments, and decreased the ROM of the adjacent segments. A greater decrease of Maximum von Mises stress was observed on the distal adjacent segment compared with the proximal adjacent segment. The decrease of Maximum von Mises stress and increment of Maximum von Mises stress on adjacent FJ in strategy B was greater than that in strategy A. Under the six operation modes, the change of the Maximum von Mises stress on the adjacent IVD and FJ was significant. The decrease in ROM in the proximal adjacent segment was greater than that of the distal adjacent segment, and the decrease of ROM in strategy A was greater than that in strategy B. This study clarified the biomechanical characteristics of adjacent segments after AdIS corrective surgery, and further biomechanical analysis of two different posterior pedicle screw placement schemes by finite element method. Our study provides a theoretical basis for the pathogenesis, prevention, and treatment of adjacent segment degeneration after corrective surgery for AdIS.

V6 vein-preserving superior segmentectomy: A potentially preferable option.

Objective: The increasing identification of pulmonary nodules has led to a growing emphasis on segmentectomy. Nevertheless, the surgical process for segmentectomy is complex and optimizing segmentectomy is a critical clinical concern. This study aimed to evaluate the safety and short- and long-term efficacy of V6-preserving superior segmentectomy. Methods: We performed a retrospective analysis of patients who underwent thoracoscopic superior segmentectomy at our hospital between January 2019 and June 2020. Eligible patients were categorized into an V6 vein-preserving segmentectomy (VVPS) group and a Non V6 vein-preserving segmentectomy (NVVPS) group depending on the preservation of V6. Primary outcome measures encompassed the evaluation of surgical safety (surgical margins, 3-year overall survival, and disease-free survival), whereas secondary measures included postoperative complication rates, operative time, estimated intraoperative blood loss, length of hospital stay, and associated costs. Results: The analysis included a final cohort of 78 patients. In the NVVPS group (n = 43), 95.3 % of patients exceeded the tumor diameter, and no positive surgical margins were observed. The 3-year overall survival (OS) and disease-free survival (DFS) rates for the NVVPS group were 95.3 %, with no significant differences in OS (p = 0.572) and DFS (P = 0.800) compared with the VVPS group. Additionally, the median total hospitalization cost for the NVVPS group was 41,400 RMB (IQR, 38,800-43,400), which was significantly lower than that of the VVPS group, showing statistical significance (P < 0.05). No statistically significant differences were observed in the incidence of postoperative complications and length of stay between the two groups (P > 0.05). Conclusion: V6-preserving superior segmentectomy is a secure and optimized surgical alternative. Its streamlined procedure facilitates easier adoption in primary healthcare facilities, rendering it a superior choice for superior segmentectomy.

Research progress on the mitochondrial mechanism of age-related non-alcoholic fatty liver.

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. Reduced activity and slower metabolism in the elderly affect the balance of lipid metabolism in the liver leading to the accumulation of lipids. This affects the mitochondrial respiratory chain and the efficiency of ß-oxidation and induces the overproduction of reactive oxygen species. In addition, the dynamic balance of the mitochondria is disrupted during the ageing process, which inhibits its phagocytic function and further aggravates liver injury, leading to a higher incidence of NAFLD in the elderly population. The present study reviewed the manifestations, role and mechanism of mitochondrial dysfunction in the progression of NAFLD in the elderly. Based on the understanding of mitochondrial dysfunction and abnormal lipid metabolism, this study discusses the treatment strategies and the potential therapeutic targets for NAFLD, including lipid accumulation, antioxidation, mitophagy and liver-protecting drugs. The purpose is to provide new ideas for the development of innovative drugs for the prevention and treatment of NAFLD.

Visible Light-Induced Coupling Cyclization Reaction of α-Diazosulfonium Triflates with α-Oxocarboxylic Acids or Alkynes.

A photocatalyst-free radical cleavage of α-diazo sulfonium salts has been developed for the first time. The reaction provides an efficient method for the generation of diazomethyl radicals from α-diazosulfonium triflates under photochemical conditions. Utilizing the in situ generated diazomethyl radicals as key intermediate, the coupling cyclization reaction of α-diazosulfonium triflates with α-oxocarboxylic acids or alkynes has been achieved. The method affords a diverse set of important 2,5-disubstituted 1,3,4-oxadiazoles and 3,5-disubstituted-1H-pyrazoles with excellent regioselectivity in a single step. A reaction mechanism involving a radical pathway was further supported by control experiments and DFT calculations.