Cost-effectiveness of robotic-assisted spinal surgery:A single-center retrospective study

Objective:Robotic-assisted spine surgeries(RASS)have been shown to enhance precision,reduce operative time,prevent complications,facilitate minimally invasive spinal surgery,and decrease revision surgery rates,leading to improved patient outco mes This study aimed to compare the cost-effectiveness of RAs's and non-robotic-assisted surgery for degenerative spine disease at a single center.Me thods:This retrospective study,including 122 patients,was conducted at a single center from March 2015 to February 2022.Patients who underwent ro bot-assisted surgery were assigned to the robotgroup,and patients who underwent non-robotic-assisted surgery were assigned to the non-mmbot group.Various data,indluding demographic information,surgical details,outcomes,and cost-effectiveness,were colected for both groups.The cost-effectiveness was determined using the incremental cost-effectiveness ratio(ICER),and subgroup analysis was conducted for patients with 1 or 2 levels of spi-nal instrumentation.The analysis was performed using STATA SE version 15 and Tree.Age Pro 2020,with Monte Caro simulations for the cost-effectiveness acceptability curve.Results The owerallICER was$22,572,but it decreased to$16,980 when considering cases with only 1or 2 levels of instrumentation.RASS is deemed cost-effective when the willi ingness to pay is$3000-$4000 if less than 2 levels of the spine are instrumented.Conchsions:The cost-effectiveness of robot icassistance be comes apparent whenthere isa reduced need for open surgeries,leading to decreased d revision rates caused by complications such as misplaced screwsor infctions.Therefore,it is advisable to allocate healthcare budget resou Irces to spine robots,as RASS PIDves to be cost-effective,partic cularly when only two or Ewer spinal levels require instrumentation.

Cost-Effectiveness Analysis of Neoadjuvant Chemotherapy with Zoledronic Acid for HER2-Negative Breast Cancer in Japan: The JONIE1 Study

Objective: Zoledronic acid (ZOL) is a nitrogen-containing bisphosphonate that induces osteoclast apoptosis and inhibits bone resorption. Adding ZOL to neoadjuvant chemotherapy has been shown to have potential anticancer benefits in women with HER2-negative breast cancer. The objective of the present study was to investigate ZOL’s cost-effectiveness from the perspective of health care payers in Japan. Methods: A Markov model was developed to evaluate the costs and effectiveness associated with ZOL + chemotherapy (CTZ) and chemotherapy (CT) alone over a 10-year time horizon. Monthly transition probabilities were estimated according to JONIE1 (Japan Organization of Neoadjuvant Innovative Expert) Study data and an extrapolated Weibull model. Health outcomes were measured in quality-adjusted life years (QALYs). Costs were calculated using year-2018 Japanese yen (JPY) (1.00 US dollars (USD) = 110.4 JPY). Model robustness was addressed through one-way and probabilistic sensitivity analysis. The costs and QALYs were discounted at a rate of 2% per year. Results: In the base case, the use of CTZ was associated with a gain of 3.94 QALYs. The incremental cost per QALY of the CTZ gain was 681,056.1 JPY (6168.99 USD) per QALY. Conclusion: It is convincing that neoadjuvant CTZ for patients with breast cancer would be expected to have statistically significant clinical efficacy. Addition of ZOL to CT might be a cost-effective option compared with CT alone.

Cost-effectiveness analysis of tele-retinopathy of prematurity screening in Iran

AIM:To conduct a cost-utility analysis of the teleretinopathy of prematurity(ROP)screening program against no screening.METHODS:A decision tree model was developed to identify and treat the infants with threshold ROP through the tele-screening system compared with no screening program from the societal perspective.We used the quality adjusted life years(QALY)index to measure the scenarios’effectiveness,which was discounted for the future years by 0.058.One hundred twenty-six randomly selected newborns with ROP required treatment were investigated to extract the treatment information.We considered the direct medical and non-medical costs in cost calculations analysed by the bottom-up approach.The figures of the model’s inputs were calculated using the Monte Carlo simulation that generated 1000 random iteration of the data,and a one-way sensitivity analysis was performed on the model to cope with the potential uncertainties.RESULTS:The total and per capita needed the budget to establish a tele-ROP screening system were estimated at over 1.5 million and 35.13 USD,respectively.The total cost of identifying and treating an ROP case in tele-screening and no screening strategies were obtained as 108.72 and 63.52 USD,respectively,and their lifetime discounted QALY gained were calculated as 15.39 and 15.11,respectively.Therefore,incremental cost-effectiveness ratio(ICER)of tele-screening strategy against the competitive strategy was achieved as 161.43 USD.CONCLUSION:Tele-ROP screening program is one of the most cost-effective interventions in the Iranian health system and has a high priority to receive a budget for implementation.

Tuberculosis Control Priorities Defined by Using Cost-Effectiveness and Burden of Disease

Objective To define TB control priorities using cost-effectiveness and burden of disease.Methods An assumed cohort of 2 000 cases was set up based on age-specific incidence of 794 newly registered smear-positive cases in Beijing in1994.Prognostic trees and model diagrams of infectivity with natural history and DOTS intervention were constructed based on the epidemiological parameters.Results DOTS reduced 89.19% of YLL,78.90% of YLD,and 99.98% of infectivity BOD.One DALY could be saved with 45.70% Yuan by DOTS with 3% discount.Sensitivity analysis showed that discount had effect on CER.Weight of age was insensitive to CER.The higher the DOTS coured rate,the more the cost-effectiveness.Conclusions DOTS is a good cost-effectiveness TB control strategy.Cost-effectiveness and burden of disease can be used to define TB control priorities.

5H-2谷物烘干机干燥箱多孔角状盒的设计与试验

为改善5H-2谷物烘干机的干燥性能,将原有角状盒改造为多孔角状盒。通过Fluent对多孔角状盒的干燥段气流场进行仿真分析,对比空载条件下干燥箱内部温度场变化情况,结果表明,装有多孔角状盒的干燥箱内部温度场较原有角状盒的分布更趋均匀。选择早稻‘中早35’稻谷,在5H-2谷物烘干机上安装多孔角状盒开展烘干试验,设置热风干燥温度为65℃,风速为8 m/s,干燥缓苏比为1∶2,结果装有多孔角状盒的烘干机干燥速率为0.798%/h~1.002%/h,烘干后爆腰增率为7.4%~10.2%,相比原有角状盒谷物烘干机,其干燥速率提高了12.1%~21.2%,爆腰增率降低了1.9%~5.1%。

部分排水条件下静力触探试验力学机理研究

在自然状态下,大部分土体的约束条件介于完全排水和不排水两者之间。在孔压静力触探试验(piezocone penetrationtest,CPTU)的贯入过程中,受探头尺寸、贯入速度和岩土材料等因素的影响,将发生部分排水现象。为研究排水条件对CPTU试验数据的影响,开展三轴压缩试验。引入应变增量比,建立考虑渐近状态的修正剑桥(Modified Cam-Clay,MCC)模型。推导考虑渐近状态MCC模型的柱孔扩张理论,提出CPTU测试数据的力学模型。通过数值模拟和模型槽试验,研究归一化贯入速度与排水系数的规律。结合CPTU数据的力学模型,获得应变增量比与排水系数的数理关系。最后以上海市苏州河地区深层排水调蓄管道系统工程的测试数据为背景,验证力学模型的正确性。结果表明:在部分排水条件下,利用考虑渐近状态的MCC模型,能够描述土体的应力-应变关系,合理解释CPTU贯入的力学机理。

煤层气水平井筛管密集分段径向射流增透方法

水平井煤层伤害后渗透性差、常规分段水力射流间距长,为提高近井壁煤层渗透性,优化设计了弹簧-液压式封隔器与注液短节,提出了以筛孔为喷嘴的煤层气水平井筛管密集分段径向射流增透方法。建立了单个筛孔径向射流破岩计算模型和近井壁煤岩增透渗流增量比计算模型,优化设计了筛管孔密、筛孔出口流速和射流排量,分析了井壁煤岩固相侵入带与滤液侵入带的渗透率比值Kγ、固相侵入带深度Hs对渗流增量比的影响规律。研究结果表明,弹簧-液压式封隔器采用了无骨架式胶筒、径向滑块和强力弹簧设计,解决了密集分段径向射流工具在筛管内的高频次封隔稳定性难题,实现了煤层气水平井筛管完井与射流增透一趟钻;在Hs=3.5 cm、Kγ=0.01条件下,筛孔径向水力射流间距减小为筛孔间距0.05 m,水平井段煤岩渗流增量比增加5.5%,实现了煤层水平井段密封分段径向射流增透作业。研究结果为解决采用筛管完井的煤层气水平井储层伤害难题提供技术指导,为近井壁煤岩增透作业提供理论支撑。

Evolution of mechanical parameters of Shuangjiangkou granite under different loading cycles and stress paths

Surrounding rocks at different locations are generally subjected to different stress paths during the process of deep hard rock excavation.In this study,to reveal the mechanical parameters of deep surrounding rock under different stress paths,a new cyclic loading and unloading test method for controlled true triaxial loading and unloading and principal stress direction interchange was proposed,and the evolution of mechanical parameters of Shuangjiangkou granite under different stress paths was studied,including the deformation modulus,elastic deformation increment ratios,fracture degree,cohesion and internal friction angle.Additionally,stress path coefficient was defined to characterize different stress paths,and the functional relationships among the stress path coefficient,rock fracture degree difference coefficient,cohesion and internal friction angle were obtained.The results show that during the true triaxial cyclic loading and unloading process,the deformation modulus and cohesion gradually decrease,while the internal friction angle gradually increases with increasing equivalent crack strain.The stress path coefficient is exponentially related to the rock fracture degree difference coefficient.As the stress path coefficient increases,the degrees of cohesion weakening and internal friction angle strengthening decrease linearly.During cyclic loading and unloading under true triaxial principal stress direction interchange,the direction of crack development changes,and the deformation modulus increases,while the cohesion and internal friction angle decrease slightly,indicating that the principal stress direction interchange has a strengthening effect on the surrounding rocks.Finally,the influences of the principal stress interchange direction on the stabilities of deep engineering excavation projects are discussed.

海底管道疲劳裂纹扩展寿命预报的影响因素分析

海底管道所处载荷环境复杂,疲劳破坏是主要失效形式之一。由于制造及环境因素,海底管道不可避免会出现裂纹缺陷,对于服役中的海底管道,预报其剩余疲劳寿命并对影响预报结果的因素进行研究具有实践意义。在保守估计法的前提下,采用MTS准则对海底管道裂纹扩展模式进行分析。利用有限元法及1/4节点位移法求解裂纹应力强度因子,随后基于Paris公式的da法对海底管道进行疲劳扩展寿命预报,最后对数值预报结果的影响因素进行探讨。结果表明,当裂纹尺寸增量Δa设置合理时,海底管道裂纹扩展寿命的预报值与试验值相接近,该数值方法能有效预报海底管道的疲劳剩余寿命。裂纹尺寸增量Δa对寿命预报影响很大,从预报精度和计算耗时两方面综合考虑给出了合理选择裂纹尺寸增量Δa的方法。形状比对管道疲劳扩展寿命的影响与初始裂纹尺寸有关。当裂纹尺寸扩展到一定值后继续增加,疲劳扩展寿命变化率并不大。所得结论为服役管道的安全性评估提供参考。

老年桡骨远端不稳定骨折不同治疗方式的成本效益分析

目的 比较老年桡骨远端不稳定骨折手术和保守治疗的临床疗效和总费用,为临床医师选择有效的治疗方式提供依据。方法 将2019年12月—2023年3月于浙江中医药大学附属富阳中医骨伤医院就诊的88例老年不稳定型桡骨远端骨折患者纳入研究。按治疗方式不同分为手术组(n=44)和夹板组(n=44)。记录患者住院期间和治疗后1年门诊复查费用、腕关节功能评分量表(gartland-werlery,GW)、腕关节患者自行评估量表(patient-ratedwristevaluation,PRWE)、影像学检查、并发症,从卫生经济学角度进行成本-效果比(costeffectivenessratio,CER)和增量成本-效果比(incrementalcost-effectivenessratio,ICER)。结果 2组腕关节功能恢复优良率及PRWE评分比较,差异无统计学意义(P>0.05)。术后1年随访,2组影像学参数均有改善;2组影像学参数比较,差异有统计学意义(P<0.05)。手术组并发症总发生率低于夹板组(P<0.05)。手术组总体费用和住院费用分别为(23080.71±2180.37)、(23728.35±2246.57)元,均高于夹板组(5333.80±1843.87)、(6614.61±1763.00)元(P<0.05),但门诊费用则低于夹板组(P<0.05)。手术组和夹板组CER分别为1383.51元/分和331.89元/分;与夹板组比较,手术组PRWE评分每降低1分需多花费5648.10元。结论 >60岁老年不稳定型桡骨远端骨折患者中,夹板固定与切开复位内固定术均具有良好的疗效,但前者可能是一种更为经济有效的治疗方案。

A cost-effectiveness assessment of the operational parameters of central HVAC systems during pandemics

The present study develops a cost-effectiveness assessment model to analyze the performance of major operational parameters of central HVAC systems in terms of airborne transmission risk,energy consumption,and medical and social cost.A typical multi-zone building model with a central HVAC system is built numerically,and the effect of outdoor air(OA)ratio(from 30%to 100%)and filtration level(MERV 13,MERV 16,and HEPA)are assessed under the conditions of five climate zones in China.Compared with the baseline case with 30%OA and MERV 13 filtration,the airborne transmission risk in zones without infector is negligibly reduced with the increase in OA ratio and the upgrade of filtration level,owing to their slight modification on the equivalent ventilation rate of virus-free air.However,depending on climate zone,a 10%increase in OA ratio results in 12.5%-78.6%and 0.1%-8.6%increase in heating and cooling energy consumption,respectively,while an upgrade of filtration level to MERV 16 and HEPA results in an increase of 0.08%-0.2%and 1.4%-2.6%,respectively.Overall,when compared to the use of 100%OA ratio and HEPA filtration,the application of 30%or 40%OA ratio and MERV 13 filtration would save annually an energy and facility related cost of$29.4 billion in China,though giving an increase of approximately$0.1 billion on medical and social cost from the increased number of confirmed cases.This study provides basic method and information for the formulation of cost-effective operational strategies of HVAC systems coping with the airborne transmission,especially in resource-limited regions.

Pore water pressure increment model for saturated Nanjing fine sand subject to cyclic loading

Three groups of dynamic triaxial tests were performed for saturated Nanjing fine sand subjected to uniform cyclic loading. The tested curves of the excess pore water pressure （EPWP） ratio variation with the ratio of the number of cycles are provided. The concept of the EPWP increment ratio is introduced and two new concepts of the effective dynamic shear stress ratio and the log decrement of effective stress are defined. It is found that the development of the EPWP increment ratio can be divided into three stages： descending, stable and ascending. Furthermore, at the stable and ascending stages, a satisfactory linear relationship is obtained between the accumulative EPWP increment ratio and natural logarithm of the effective dynamic shear stress ratio. Accordingly, the EPWP increment ratio at the number of cycles N has been deduced that is proportional to the log decrement of effective stress at the cycle number N-l, but is independent of the cyclic stress amplitude. Based on the analysis, a new EPWP increment model for saturated Nanjing fine sand is developed from tested data fitting, which provides a better prediction of the curves of EPWP generation, the number of cycles required for initial liquefaction and the liquefaction resistance.

Effect of consolidation ratios on maximum dynamic shear modulus of sands

The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the field or in the laboratory. The effect of consolidation ratios on the maximum DSM for two types of sand is investigated by using resonant column tests. And, an increment formula to obtain the maximum DSM for cases of consolidation ratio κc>1 is presented. The results indicate that the maximum DSM rises rapidly when κc is near 1 and then slows down, which means that the power function of the consolidation ratio increment κc-1 can be used to describe the variation of the maximum DSM due to κc>1. The results also indicate that the increase in the maximum DSM due to κc>1 is significantly larger than that predicted by Hardin and Black's formula.

Experimental Investigation on Combustion Performance of Solid Propellant Subjected to Erosion of Particles with Different Concentrations

A test device with rectangular channel is developed to study the combustion performance of solid propellant in high temperature particles erosion.The flowfields in this newdevice and a test device with circular channels are simulated numerically.The particle erosion experiments in these two devices are carried out under different particle concentrations.The results showthat the test device with rectangular channel can effectively improve the clarity and precision of combustion diagnosis image and can be used for research on combustion performance of solid propellant under lowconcentration particle erosion;the circular channel device has good particle convergent effect,provides high concentration particle erosion,and can be used for research on the combustion performance of solid propellant under high concentration particle erosion.The experiment data indicates that the propellant burning rate does not change obviously in lower particle concentration;the propellant with lower static burning rate increases remarkably under particle erosion,while the propellant with high static burning rate is not sensitive to the particle erosion.

关于冠心病患者PCI术后双心治疗成本-效果比的临床研究

目的比较冠心病(coronary artery disease,CAD)患者经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)术后双心治疗与常规治疗的成本-效果,为冠心病患者PCI术后双心治疗提供依据。方法共纳入2021年8月—2023年6月于首都医科大学附属北京安贞医院住院行PCI手术治疗的195例CAD患者,随机分为双心治疗组(79例)与常规治疗组(116例)。通过2周,1、3、6、12、18个月随访,比较两种治疗方法的疗效,计算成本-效果比(cost-effectiveness ratio,CER)、增量成本-效果比(incremental cost-effectiveness ratio,ICER)。结果双心治疗组共79例,其中1例因急性冠脉综合征(acute coronary syndrome,ACS)再入院行PCI治疗,有效率为98.73%;常规治疗组116例,10例因ACS再入院,7例行PCI治疗,1例行冠脉造影检查,2例保守治疗,有效率为91.38%,双心治疗组的临床有效率明显高于常规治疗组(P=0.028)。常规治疗组的CER为766.74,双心治疗组CER为713.44,双心治疗的CER显著低于常规治疗。ICER为50.86。结论与常规治疗比较,冠心病患者PCI术后双心治疗有更显著的临床疗效,较低的CER,且有更好的卫生经济学价值。

框支密肋复合墙结构地震易损性研究

地震易损性分析通过概率计算建立地震强度和结构损伤之间的关系,可以实现结构地震风险预测和评估。为了对框支密肋复合墙结构在不同地震强度下的抗震能力进行评估,该文采用OpenSEES有限元软件,选用密肋复合墙的刚架-等效斜撑简化模型,建立结构整体分析模型,基于增量动力时程分析(IDA)和易损性分析,研究不同参数的变化对结构抗震性能的影响。结果表明:转换层刚度比的变化对结构性能影响显著,结构竖向布置均匀对抗震有利,建议8度区框支密肋复合墙结构的刚度比取值为1.0~2.5;肋柱数量、砌块强度的变化可对结构的抗震性能产生影响,应合理选择;混凝土强度等级对结构的抗震性能影响较大,在实际应用中应在满足规范要求的前提下选择较大的混凝土强度等级。

一种改进的增量型随机权神经网络及应用

增量型随机权神经网络(I-RVFL)具有良好的泛化性能,在一定程度上避免了过拟合问题,但是,I-RVFL网络的输入权值和隐藏层偏差是从固定范围内随机生成的,可能会导致模型不稳定。针对上述问题,论文提出一种改进的I-RVFL网络。首先,利用指数加权平均对历史数据依赖随时间指数衰减且能平滑数据中异常值的特点,优化随机分配的输入权值与偏差。然后,将凸函数的下降梯度比应用到模型误差序列中,建立神经网络权值配置的约束条件。在UCI数据集上的仿真结果表明,改进的I-RVFL网络在分类精度以及稳定性上有显著提高。将论文方法应用于红外火焰识别,检测准确率达到98%,验证了该网络的有效性和实用性。

5种排水条件下饱和重塑黄土三轴剪切特性

为了深化对工程实践中黄土排水状态和影响的认识,通过三轴剪切试验控制应变增量比研究了饱和重塑黄土在不排水、强制吸水、自由排水、强制排水、部分排水5种排水条件下的剪切特性。结果表明,饱和重塑黄土的剪切特性与排水条件密切相关:在不排水和强制吸水条件下,黄土试样表现为应变软化,从广义上讲,在强制吸水条件下试样的剪胀性被强制发挥;在自由排水和强制排水条件下,黄土试样表现出硬化趋势,其中,在强制排水条件下试样的剪胀性受到抑制;在部分排水条件下,黄土试样为应变软化或应变软化到硬化的过渡状态,此时,黄土的剪切特性不仅与应变增量比有关,也受到孔隙比的影响,应变增量比越接近0,试样的软化程度越明显,而试样的孔隙比越小,其在剪切初始阶段的剪胀趋势越明显,试样的峰值强度和残余强度越高。另外,基于渐近状态方程和剪胀方程,量化分析了饱和重塑黄土的渐近状态和剪胀性,发现试样的渐近状态应力比与剪胀程度呈负相关关系。

考虑几何参数影响的联肢剪力墙抗震性能研究

耦联比是反映联肢剪力墙墙肢与连梁的耦合作用程度的重要参数。然而,耦联比与结构体系的非线性特征高度相关,导致在结构初步设计阶段难以确定。因此,有必要引入在初步设计阶段即可方便确定的其他参数。本研究采用连梁跨高比和墙肢高宽比来代替耦联比,设计了9个联肢剪力墙原型结构,利用增量动力分析方法,研究了连梁跨高比和墙肢高宽比对钢筋混凝土联肢剪力墙地震易损性特征和极限承载力的影响。采用双因子二次响应面法进一步揭示了连梁跨高比和墙肢高宽比的组合对联肢剪力墙整体性能的影响,得到响应变量的最优值,并利用曲线拟合找出连梁跨高比和墙肢高宽比最优关系。结果表明,连梁跨高比和墙肢高宽比可以有效地作为耦联比的补充,在初步设计阶段作为衡量钢筋混凝土联肢剪力墙的整体抗震性能的参数。

基于锚索内力增量比指标的边坡安全性预警研究

预应力锚索作为主动加固手段,可提高边坡的稳定性。但公路边坡的锚固工程并非永久保障,随着岩土体外部荷载以及内部结构的改变,边坡仍然存在失稳破坏的潜在风险。因此,边坡安全性预警研究对于防灾减灾有着重要意义。以某实际预应力锚索加固边坡工程为例,采用数值仿真方式,通过建立边坡稳定性计算模型,得到不同锚索初始预应力下锚索内力增量与边坡岩土体强度折减系数的关系曲线,并将边坡滑动面起始发育和滑动面贯通分别对应的边坡岩土体强度折减系数λ_(1)、λ_(2)对应的点作为边坡安全性预警点,建立以锚索内力增量比作为边坡安全稳定状态的预警指标,提出了基于锚索内力增量比的边坡安全性预警方法和判别标准,该方法消除了锚索初始预应力的影响,便于工程应用,并得到锚索内力增量比在不同阶段的边坡安全性预警阈值与锚索初始预应力呈现出e指数关系,可用公式y=AeBx表示,实际应用中可根据这一关系式实现不同锚索预应力加固边坡安全稳定状态的预警。