Machine learning applications for the prediction of extended length of stay in geriatric hip fracture patients

BACKGROUND Geriatric hip fractures are one of the most common fractures in elderly individuals,and prolonged hospital stays increase the risk of death and complications.Machine learning(ML)has become prevalent in clinical data processing and predictive models.This study aims to develop ML models for predicting extended length of stay(eLOS)among geriatric patients with hip fractures and to identify the associated risk factors.AIM To develop ML models for predicting the eLOS among geriatric patients with hip fractures,identify associated risk factors,and compare the performance of each model.METHODS A retrospective study was conducted at a single orthopaedic trauma centre,enrolling all patients who underwent hip fracture surgery between January 2018 and December 2022.The study collected various patient characteristics,encompassing demographic data,general health status,injury-related data,laboratory examinations,surgery-related data,and length of stay.Features that exhibited significant differences in univariate analysis were integrated into the ML model establishment and subsequently cross-verified.The study compared the performance of the ML models and determined the risk factors for eLOS.RESULTS The study included 763 patients,with 380 experiencing eLOS.Among the models,the decision tree,random forest,and extreme Gradient Boosting models demonstrated the most robust performance.Notably,the artificial neural network model also exhibited impressive results.After cross-validation,the support vector machine and logistic regression models demonstrated superior performance.Predictors for eLOS included delayed surgery,D-dimer level,American Society of Anaesthesiologists(ASA)classification,type of surgery,and sex.CONCLUSION ML proved to be highly accurate in predicting the eLOS for geriatric patients with hip fractures.The identified key risk factors were delayed surgery,D-dimer level,ASA classification,type of surgery,and sex.This valuable information can aid clinicians in allocating resources more efficiently to meet patient demand effectively.

Dynamics of solitons in Bose-Einstein condensate with time-dependent atomic scattering length

The evolution of solitons in Bose-Einstein condensates （BECs） with time-dependent atomic scattering length in an expulsive parabolic potential is studied. Based on the extended hyperbolic function method, we successfully obtain the bright and dark soliton solutions. In addition, some new soliton solutions in this model are found. The results in this paper include some in the literature （Phys. Rev. Lett. 94（2005）050402 and Chin. Phys. Lett. 22（2005） 1855）.

The extending length calculation of hydraulic drive non-metallic completion screen pipe running into ultra-short radius horizontal well

Focusing on the extending length restriction of the completion screen pipe resistance running into ultra-short radius horizontal well,this paper proposed technology of hydraulic drive completion tubular string running into ultra-short radius horizontal well.Innovative hydraulic drive tools and string structure are designed,which are composed of guide tubing,hydraulic drive tubing and non-metallic completion screen pipe from inside to outside.A novel mechanical-hydraulic coupling model is established.Based on the wellbore structure of an ultra-short radius horizontal well for deep coalbed methane,the numerical calculations of force and hydraulic load on tubular strings were accomplished by the mechanical-hydraulic coupling model.The results show that the extending length of completion tubular string with the hydraulic drive is 17 times that of conventional completion technology under the same conditions.The multi-factor orthogonal design is adopted to analyze the numerical calculations,and the results show that the extending length of the completion tubular string is mainly affected by the completion tubular string structure and the friction coefficient between the non-metallic composite continuous screen pipe and the wellbore.Two series of hydraulic drive completion tubular string structures suitable for ultra-short radius horizontal wells under different conditions are optimized,with the extending limits of 381 m and 655 m,respectively.These researches will provide theoretical guidance for design and control of hydraulic drive non-metallic composite continuous completion screen pipe running into ultra-short radius horizontal wells.

二次雷达与飞行器之间信息交换方法与应用

文章介绍了二次雷达与飞行器之间进行信息交换的方法及其应用。首先将二次雷达从基本型A/C模式升级到S模式,再利用S模式的信息交换功能,实现地面发起的信息交换和空中发起的信息交换功能。我们通过对信息交换流程的设计,实现了飞机识别符的获取与确认;通过信息交换实现了相邻地面雷达站之间的S模式协同监视。采用协同监视,降低询问频次,减少二次雷达的异步应答干扰,提高S模式目标监视的可靠性和连续性。

Effect of Structural Parameters of Double Shielded TIG Torch on the Fusion Zone Profile for 0Cr13Ni5Mo Martensitic Stainless Steel

The effects of double shielded TIG （tungsten inert gas） torch＇s structural parameters, including the flow rate ratio between the inner and outer layers of gas and the extended length of the electrode （abbreviated as ELE in this work）, on the fusion zone profile have been investigated for OCrl3NiSMo martensitic stainless steel. Results show that the double shielded TIG process yields relatively high penetration of the weld pool in a broad range of the structural parameters. ELE over 3 mm is too large and causes adverse reactions on the protection of electrode. The outer gas with relatively high flow rate or the outer layer with high oxygen content is conducive to the oxygen dissolved into the arc, which results in the oxidation of the weld pool surface and the electrode tip. The double shielded TIG welded metal was tested and presented good impact property.