Surgical intervention combined with weight-bearing walking training promotes recovery in patients with chronic spinal cord injury:a randomized controlled study

For patients with chronic spinal cord injury,the co nventional treatment is rehabilitation and treatment of spinal cord injury complications such as urinary tract infection,pressure sores,osteoporosis,and deep vein thrombosis.Surgery is rarely perfo rmed on spinal co rd injury in the chronic phase,and few treatments have been proven effective in chronic spinal cord injury patients.Development of effective therapies fo r chronic spinal co rd injury patients is needed.We conducted a randomized controlled clinical trial in patients with chronic complete thoracic spinal co rd injury to compare intensive rehabilitation(weight-bearing walking training)alone with surgical intervention plus intensive rehabilitation.This clinical trial was registered at ClinicalTrials.gov(NCT02663310).The goal of surgical intervention was spinal cord detethering,restoration of cerebrospinal fluid flow,and elimination of residual spinal cord compression.We found that surgical intervention plus weight-bearing walking training was associated with a higher incidence of American Spinal Injury Association Impairment Scale improvement,reduced spasticity,and more rapid bowel and bladder functional recovery than weight-bearing walking training alone.Overall,the surgical procedures and intensive rehabilitation were safe.American Spinal Injury Association Impairment Scale improvement was more common in T7-T11 injuries than in T2-T6 injuries.Surgery combined with rehabilitation appears to have a role in treatment of chronic spinal cord injury patients.

Effect of low-speed waterjet pressure on the rock-breaking performance of unsubmerged cavitating abrasive waterjet

Unsubmerged cavitating abrasive waterjet(UCAWJ)has been shown to artificially create a submerged environment that produces shear cavitation,which effectively enhances rock-breaking performance.The shear cavitation generation and collapse intensity depend on the pressure difference between the intermediate high-speed abrasive waterjet and the coaxial low-speed waterjet.However,the effect of the pressure of the coaxial low-speed waterjet is pending.For this purpose,the effect of low-speed waterjet pressure on rock-breaking performance at different standoff distances was experimentally investigated,and the effects of erosion time and ruby nozzle diameter on erosion performance were discussed.Finally,the micromorphology of the sandstone was observed at different locations.The results show that increased erosion time and ruby nozzle diameter can significantly improve the rock-breaking performance.At different standoff distances,the mass loss increases first and then decreases with the increase of low-speed waterjet pressure,the maximum mass loss is 10.4 g at a low-speed waterjet pressure of0.09 MPa.The surface morphology of cavitation erosion was measured using a 3D profiler,the increase in both erosion depth and surface roughness indicated a significant increase in the intensity of the shear cavitation collapse.At a low-speed waterjet pressure of 0.18 MPa,the cavitation erosion surface depth can reach 600μm with a roughness of 127μm.

Effect of Brisk Walking on Self-Care Agency or Care Dependency among Colorectal Cancer Patients with Permanent Stoma

Objective:The purpose of this study was to determine the effectiveness of brisk walking as an intervention for self-care agency and care dependency in patients with permanent colorectal cancer stoma.Method:This study adopted a quasi-experimental research design,specifically a non-equivalent control group pre-test and post-test design.Utilizing the Exercise of Self-Care Agency Scale(ESCA)and Care Dependency Scale(CDS),a survey was administered to 64 patients from a hospital in Shandong Province.The statistical methods used for analyzing data included frequency,mean,standard deviation(SD),independent t-test,P-value calculation,and dependent t-test.Result:After two months of a brisk walking exercise program,participants in the experimental group had a higher level of self-care agency than before the experiment(P<0.05),and their level of care dependency was significantly reduced(P<0.05).Participants in the control group also showed higher levels of self-care agency(P<0.05)and lower levels of care dependency(P<0.05)after two months compared to their levels before the two months.Conclusion:The brisk walking program had a positive impact on patients’self-care agency and reduced their care dependency.

Synthesis of Branched Polyethylene via Bulky α-Diimine Nickel(II)-Catalyzed Ethylene Chain-Walking Polymerization

The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.

A Wire-Driven Series Elastic Mechanism Based on Ultrasonic Motor for Walking Assistive System

In order to improve the elderly people's quality of life,supporting their walking behaviors is a promising technology.Therefore,based on one ultrasonic motor,a wire-driven series elastic mechanism for walking assistive system is proposed and investigated in this research.In contrast to tradition,it innovatively utilizes an ultrasonic motor and a wire-driven series elastic mechanism to achieve superior system performances in aspects of simple structure,high torque/weight ratio,quiet operation,quick response,favorable electromagnetic compatibility,strong shock resistance,better safety,and accurately stable force control.The proposed device is mainly composed of an ultrasonic motor,a linear spring,a steel wire,four pulleys and one rotating part.To overcome the ultrasonic motor's insufficient output torque,a steel wire and pulleys are smartly combined to directly magnify the torque instead of using a conventional gear reducer.Among the pulleys,there is one tailored pulley playing an important role to keep the reduction ratio as 4.5 constantly.Meanwhile,the prototype is manufactured and its actual performance is verified by experimental results.In a one-second operating cycle,it only takes 86 ms for this mechanism to output an assistive torque of 1.6 N·m.At this torque,the ultrasonic motor's speed is around 4.1 rad/s.Moreover,experiments with different operation periods have been conducted for different application scenarios.This study provides a useful idea for the application of ultrasonic motor in walking assistance system.

Theoretical and Numerical Studies on the Coupling Deformation of Global Lateral Buckling and Walking of Submarine Pipeline

Buckling initiation devices/techniques,including sleepers,distributed buoyancy,snake lay,and residual curvature method(RCM),have recently been widely applied in engineering.These initiated buckles may induce a long pipeline to transform into multiple short pipeline segments,which promote the occurrence of pipeline walking.Thus,a pipeline,which is designed to buckle laterally,may laterally and axially displace over time when subjected to repeated heating and cooling cycles.This study aims to reveal the coupling mechanism of pipeline walking and global lateral buckling.First,an analytic solution is proposed to estimate the walking of pipeline segments between two adjacent buckles.Then,the sensitivity of this method to heating and cooling cycles is analyzed.Results show the applicability of the proposed walking analytical solution of buckling pipelines.Subsequently,an influence analysis of walking on global buckling,including the capacity of buckling initiation,buckling amplitude,buckling mode,and failure assessment of the buckling pipeline,is performed.The results reveal that the effect of walking on the buckling axial force is negligible.However,pipeline walking will aggravate the asymmetry of the pipeline buckling and the failure parameters of the pipeline during the post-buckling.

A new passive transfemoral prosthesis mechanism based on 3R36 knee and ESAR foot providing walking and squatting

Researchers have proposed various linkage mechanisms to connect knee and ankle joints for above-knee prosthe-ses,but most of them only offer natural walking.However,studies have shown that people assume a squatting posture during daily activities.This paper introduces a novel mechanism that connects the knee joint with the foot-ankle joint to enable both squatting and walking.The prosthetic knee used is the well-known 3R36,while the energy storing and return(ESAR)prosthetic foot is used for the ankle-foot joint.To coordinate knee and ankle joint movements,a six-bar linkage mechanism structure is proposed.Simulation results demonstrate that the proposed modular transfemoral prosthesis accurately mimics the motion patterns of a natural human leg during walking and squatting.For instance,the prosthesis allows a total knee flexion of more than 140°during squatting.The new prosthesis design also incorporates energy-storing mechanisms to reduce energy expenditure during walking for amputees.

Strong invariance principle for a counterbalanced random walk

We study a counterbalanced random walkS_(n)=X_(1)+…+X_(n),which is a discrete time non-Markovian process andX_(n) are given recursively as follows.For n≥2,X_(n) is a new independent sample from some fixed law̸=0 with a fixed probability p,andX_(n)=−X_(v(n))with probability 1−p,where v(n)is a uniform random variable on{1;…;n−1}.We apply martingale method to obtain a strong invariance principle forS_(n).

Mobility edges and localization characteristics in one-dimensional quasiperiodic quantum walk

We construct a one-dimensional quasiperiodic quantum walk to investigate the localization–delocalization transition.The inverse participation ratio and Lyapunov exponent are employed as two indexes to determine the mobility edge, a critical energy to distinguish the energy regions of extended and localized states. The analytical solution of mobility edge is obtained by the Lyapunov exponents in global theory, and the consistency of the two indexes is confirmed. We further study the dynamic characteristics of the quantum walk and show that the probabilities are localized to some specific lattice sites with time evolution. This phenomenon is explained by the effective potential of the Hamiltonian which corresponds to the phase in the coin operator of the quantum walk.

ON THE EMPTY BALLS OF A CRITICAL OR SUBCRITICAL BRANCHING RANDOM WALK

Let{Z_(n)}_(n)≥0 be a critical or subcritical d-dimensional branching random walk started from a Poisson random measure whose intensity measure is the Lebesugue measure on R^(d).Denote by R_(n):=sup{u>0:Z_(n)({x∈R^(d):∣x∣<u})=0}the radius of the largest empty ball centered at the origin of Z_(n).In this work,we prove that after suitable renormalization,Rn converges in law to some non-degenerate distribution as n→∞.Furthermore,our work shows that the renormalization scales depend on the offspring law and the dimension of the branching random walk.This completes the results of Révész[13]for the critical binary branching Wiener process.

Research on Feature Extraction Method for Low-Speed Reciprocating Bearings Based on Segmented Short Signal Modulation Signal Bispectrum Slicing

Bearing condition monitoring and fault diagnosis (CMFD) can investigate bearing faults in the early stages, preventing the subsequent impacts of machine bearing failures effectively. CMFD for low-speed, non-continuous operation bearings, such as yaw bearings and pitch bearings in wind turbines, and rotating support bearings in space launch towers, presents more challenges compared to continuous rolling bearings. Firstly, these bearings have very slow speeds, resulting in weak collected fault signals that are heavily masked by severe noise interference. Secondly, their limited rotational angles during operation lead to a restricted number of fault signals. Lastly, the interference from deceleration and direction-changing impact signals significantly affects fault impact signals. To address these challenges, this paper proposes a method for extracting fault features in low-speed reciprocating bearings based on short signal segmentation and modulation signal bispectrum (MSB) slicing. This method initially separates short signals corresponding to individual cycles from the vibration signals based on encoder signals. Subsequently, MSB analysis is performed on each short signal to generate MSB carrier-slice spectra. The optimal carrier frequency and its corresponding modulation signal slice spectrum are determined based on the carrier-slice spectra. Finally, the MSB modulation signal slice spectra of the short signal set are averaged to obtain the overall average feature of the sliced spectra.

City Walk:美好生活视域下的体文旅融合发展研究

City Walk是一种以漫步为主要途径来体验城市风景和文化氛围的新型“微旅游”方式。本文在分析City Walk的内在机理及价值的基础上,对以美好生活视域下City Walk中体文旅融合所面临的现实困境与纾困路径进行分析。研究发现,City Walk中体文旅融合的现实困境为缺乏相应科学健身知识储备、影响旅游目的地居民生活、过度商业化与文化原貌冲突、过于集中的City Walk路线。据此提出纾困路径:在人才支持方面要培育体文旅复合人才,组建专业队伍;在政策支持方面要完善法律法规,建立奖惩机制;在创新支持方面要持续探索新区域,助力体文旅高质量发展;在宣传支持方面要打造City Walk中的城市IP属性,扩大知名度。

从“走向自然”到“走向城市”:休闲美学视域下的City Walk

“如何休闲”之问具有“顶天立地”的双重品格,既关乎具体可感的现实生活样态,又牵涉本己本真的存在与生命之思。以往,人们通过践履山水自然而追寻人性自然。而今,“走向自然”的休闲难以与日常生活相协调,亟待思考的是如何另辟蹊径。City Walk是一种时兴的、以徒步为主要方式来探索城市空间、感受别样趣味的休闲活动,其低成本、慢节奏、益身心等特点极大地推动了休闲的开展,其“反叛技术”“背离秩序”的超越性品格规避了休闲异化的风险,其维持身心健康、促进友好交往、建构和谐关系及回归诗意栖居的美学价值助力人们属人地生存与属人地休闲。研究其活动特质与美学价值,既可为休闲美学添砖加瓦,又可为城市生活建言献策。

Heat Kernel Estimates on Simple Random Walks and On-Diagonal Upper Bounds

We primarily provide several estimates for the heat kernel defined on the 2-dimensional simple random walk. Additionally, we offer an estimate for the heat kernel on high-dimensional random walks, demonstrating that the heat kernel in higher dimensions converges rapidly. We also compute the constants involved in the estimate for the 1-dimensional heat kernel. Furthermore, we discuss the general case of on-diagonal estimates for the heat kernel.

从City Walk到乡村旅游

自2022年开始,一种名为City Walk(城市漫步)的旅行方式广受推崇,网上的路线攻略、结伴成团、报道评论越来越多。City Walk原是20世纪30年代发源于英国的一种城市旅游形式,指的是几个人在一起,在专业讲述员的带领下,有计划地行走在一条独特的道路上。但现在流行的这一概念更多指的是深入到城市的街巷、情境和空间,非功利化、无目的性地随意漫步游走,不受他人评价和引导的影响。

建筑可阅读 城市可漫步——以City Walk为“小切口”打开名城保护“大视野”

周末约上两三朋友,就近寻一处城市街头漫步,看看老建筑,逛逛特色小店,点一杯咖啡,或是品尝地道的当地小吃。这种生活方式被称为“City Walk”(意为“城市漫步”),已成为当下年轻人城市生活的新方式。“City Walk”指参与者行走在一条独特的城市路线上,用脚步探索城市,深入城市肌理,感受城市独特气质的生活方式。根据《中国旅行消费趋势洞察白皮书(2023年版)》,2023年旅行消费的四大新趋势是“小众独特、自在松弛、未知惊喜、深度在地”.

基于Deep Walk-GATVAE的中小微企业服务推荐探析

为了解决中小微企业在推荐服务时,因为企业节点表征使用One-hot编码维度过高导致服务推荐不准确的问题,提出了一种基于随机游走嵌入的图注意力变分自编码器网络模型(DeepWalk-GATVAE)的中小微企业服务推荐算法。首先是为解决数据的稀疏性,使用DeepWalk进行分布特征表示,并将特征转化为低维的表征;其次输入GATVAE网络模型挖掘企业和服务之间的关联;最后对使用的超参数进行调整,找到最优的参数选择。测试结果表明,本研究提出的算法ROC_AUC和AP值分别为0.8475和0.8626,与常见的推荐算法相比,提高了服务推荐的准确性,有效解决了中小微企业服务数据稀疏的问题。

基于随机引物的PCR-Walking技术

染色体步行技术越来越倾向于采用PCR技术,不同随机引物的应用产生了不同的方法。针对目前应用较广的热不对称交错PCR(TAIL-PCR)、单寡核苷酸巢式PCR(SON-PCR)、基于RAPD原理的单引物PCR、位点寻找PCR和自我形成接头式PCR进行了介绍,侧重说明了热不对称交错PCRTAIL-PCR的原理、优缺点及应用。

Kinematics and Dynamics Analysis of a Quadruped Walking Robot with Parallel Leg Mechanism

It is desired to require a walking robot for the elderly and the disabled to have large capacity,high stiffness,stability,etc.However,the existing walking robots cannot achieve these requirements because of the weight-payload ratio and simple function.Therefore,Improvement of enhancing capacity and functions of the walking robot is an important research issue.According to walking requirements and combining modularization and reconfigurable ideas,a quadruped/biped reconfigurable walking robot with parallel leg mechanism is proposed.The proposed robot can be used for both a biped and a quadruped walking robot.The kinematics and performance analysis of a 3-UPU parallel mechanism which is the basic leg mechanism of a quadruped walking robot are conducted and the structural parameters are optimized.The results show that performance of the walking robot is optimal when the circumradius R,r of the upper and lower platform of leg mechanism are 161.7 mm,57.7 mm,respectively.Based on the optimal results,the kinematics and dynamics of the quadruped walking robot in the static walking mode are derived with the application of parallel mechanism and influence coefficient theory,and the optimal coordination distribution of the dynamic load for the quadruped walking robot with over-determinate inputs is analyzed,which solves dynamic load coupling caused by the branches’ constraint of the robot in the walk process.Besides laying a theoretical foundation for development of the prototype,the kinematics and dynamics studies on the quadruped walking robot also boost the theoretical research of the quadruped walking and the practical applications of parallel mechanism.

Planning and Control of COP-Switch-Based Planar Biped Walking

Efficient walking is one of the main goals of researches on biped robots. A feasible way is to translate the understanding from human walking into robot walking, for example, an artificial control approach on a human like walking structure. In this paper, a walking pattern based on Center of Pressure （COP） switched and modeled after human walking is introduced firstly. Then, a parameterization method for the proposed walking gait is presented. In view of the complication, a multi-space planning method which divides the whole planning task into three sub-spaces, including simplified model space, work space and joint space, is proposed. Furthermore, a finite-state-based control method is also developed to implement the proposed walking pattern. The state switches of this method are driven by sensor events. For convincing verification, a 2D simulation system with a 9-1ink planar biped robot is developed. The simulation results exhibit an efficient walking gait.