Prognostic value of preoperative weight loss-adjusted body mass index on survival after esophagectomy for esophageal squamous cell carcinoma

BACKGROUND The impact of body mass index(BMI)on survival in patients with esophageal squamous cell carcinoma(ESCC)undergoing surgery remains unclear.Therefore,a definition of clinically significant BMI in patients with ESCC is needed.AIM To explore the impact of preoperative weight loss(PWL)-adjusted BMI on overall survival(OS)in patients undergoing surgery for ESCC.METHODS This retrospective study consisted of 1545 patients who underwent curative resection for ESCC at West China Hospital of Sichuan University between August 2005 and December 2011.The relationship between PWL-adjusted BMI and OS was examined,and a multivariate analysis was performed and adjusted for age,sex,TNM stage and adjuvant therapy.RESULTS Trends of poor survival were observed for patients with increasing PWL and decreasing BMI.Patients with BMI≥20.0 kg/m2 and PWL<8.8%were classified into Group 1 with the longest median OS(45.3 mo).Patients with BMI<20.0 kg/m2 and PWL<8.8%were classified into Group 2 with a median OS of 29.5 mo.Patients with BMI≥20.0 kg/m2 and PWL≥8.8%(HR=1.9,95%CI:1.5-2.5),were combined into Group 3 with a median OS of 20.1 mo.Patients in the three groups were associated with significantly different OS(P<0.05).In multivariate analysis,PWL-adjusted BMI,TNM stage and adjuvant therapy were identified as independent prognostic factors.CONCLUSION PWL-adjusted BMI has an independent prognostic impact on OS in patients with ESCC undergoing surgery.BMI might be an indicator for patients with PWL<8.8%rather than≥8.8%.

Field report:Research along the Yarlung Suture Zone in Southern Tibet,a persistent geological frontier

The Yarlung Suture Zone in Southern Tibet marks the boundary between India and Asia-formerly separated by an ocean basin-and is a critical record of the tectonic processes that created the Tibetan Plateau. The Yarlung Suture Zone is also a frontier research area, as difficulty of access has limited research activity, providing ample opportunities for new discoveries. This paper documents field research conducted by the authors along the Yarlung suture zone in eastern Xigaze(Shigatse, Rikaze)County, ~250 km west of the city of Lhasa, in July 2017. The goal of this research was to map the Suture Zone structure in detail, and more specifically to understand the branching relationships between two major fault systems-the Great Counter Thrust and Gangdese Thrust. A summary of early geological exploration is included to provide context for this research.

Prediction of hot-rolled strip crown based on Boruta and extremely randomized trees algorithms

The quality of hot-rolled steel strip is directly affected by the strip crown.Traditional machine learning models have shown limitations in accurately predicting the strip crown,particularly when dealing with imbalanced data.This limitation results in poor production quality and efficiency,leading to increased production costs.Thus,a novel strip crown prediction model that uses the Boruta and extremely randomized trees(Boruta-ERT)algorithms to address this issue was proposed.To improve the accuracy of our model,we utilized the synthetic minority over-sampling technique to balance the imbalance data sets.The Boruta-ERT prediction model was then used to select features and predict the strip crown.With the 2160 mm hot rolling production lines of a steel plant serving as the research object,the experimental results showed that 97.01% of prediction data have an absolute error of less than 8 lm.This level of accuracy met the control requirements for strip crown and demonstrated significant benefits for the improvement in production quality of steel strip.