Search

High‐level voltage and extremely low current are the main characteristics of Triboelectric Nanogenerators (TENGs). Despite TENGs, their Integrated Energy Storage (IES) units like supercapacitors and battery units require low‐level voltage and a high amount of current for self‐charging power applications. Using proper materials with higher triboelectric charge density is the most common approach to enhance the output current of TENGs. However, this approach alone does not satisfy the requirement of the integrated energy storage units, in which a relatively low voltage along with a sufficiently high current is needed. Consequently, alternative approaches such as employing a power management circuitry have been proposed. This paper introduces a technique based on the texture of multiple TENGs with identical small surface areas to adapt the TENGs to their IESs, specifically tailored for wearable electronics. Some experiments are conducted to evaluate the merits and limitations of the proposed approach. The experimental and analytical results are thoroughly analyzed to show the capabilities and restrictions of the method. [ABSTRACT FROM AUTHOR]

A novel gear mechanism named high-order multi-segment deformed eccentric non-circular gear was proposed for achieving the unification of non-circular gears with typical-form pitch curve and non-circular gears with free-form pitch curve. The transmission mechanism of the high-order multi-segment deformed eccentric non-circular gear was analyzed, and the unified mathematical expression of eccentric gears was established. The non-circular gears with free-form pitch curve could be constructed based on the proposed high-order multi-segment deformed eccentric non-circular gear by changing the parameters. Moreover, the transmission characteristics were discussed, such as the transmission ratio relationship, convexity distinguished conditions, curvature radius of pitch curve. The visual design and simulation software and generation software of tooth profile for non-circular gears are compiled based on MATLAB, and was verified with the example. This novelty gear was applied to the drive mechanism of the metering pump. The mathematical model of non-circular gear-crank slider mechanism is established and the 3D model and virtual prototype experiment of the mechanism are accomplished. The application showed that the high-order multi-segment deformed eccentric non-circular gears were feasible in practice. [ABSTRACT FROM AUTHOR]

Upper limb tremor is a prominent symptom of both Parkinson’s disease and essential tremor. Its kinematic parameters overlap substantially for these two pathological conditions, thus leading to high rate of misdiagnosis, especially for community doctors. Several groups have proposed various methods for improving differential diagnosis. These prior studies have attempted to identify better kinematic parameters, however they have mainly focused on single limb features including tremor intensity, tremor frequency, and tremor variability. In this paper, we propose a wearable system for multi-segment assessment of upper limb tremor and differential diagnosis of Parkinson’s disease versus essential tremor. The proposed system collected tremor data from both wrist and fingers simultaneously. From this data, we extracted multi-segment features in the form of phase relationships between limb segments. Using support vector machine classifiers, we then performed differential diagnosis from the extracted features. We evaluated the performance of the proposed system on 19 Parkinson’s disease patients and 12 essential tremor patients. Moreover, we also assessed the performance cost associated with reducing task load and sensor array size. The proposed system reached perfect accuracy in leave-one-out cross validation. Task reduction and sensor array reduction were associated with penalties of 2% and 9-10% respectively. The results demonstrated that the proposed system could be simplified for clinical applications, and successfully applied to the differential diagnosis of Parkinson’s disease versus essential tremor in real-world setting.

Abstract Background Spine disorders are becoming more prevalent in today’s ageing society. Motion abnormalities have been linked to the prevalence and recurrence of these disorders. Various protocols exist to measure thoracolumbar spine motion, but a standard multi-segmental approach is still missing. This study aims to systematically evaluate the literature on stereophotogrammetric motion analysis approaches to quantify thoracolumbar spine kinematics in terms of measurement reliability, suitability of protocols for clinical application and clinical significance of the resulting functional assessment. Methods Electronic databases (PubMed, Scopus and ScienceDirect) were searched until February 2022. Studies published in English, investigating the intersegmental kinematics of the thoracolumbar spine using stereophotogrammetric motion analysis were identified. All information relating to measurement reliability; measurement suitability and clinical significance was extracted from the studies identified. Results Seventy-four studies met the inclusion criteria. 33% of the studies reported on the repeatability of their measurement. In terms of suitability, only 35% of protocols were deemed suitable for clinical application. The spinous processes of C7, T3, T6, T12, L1, L3 and L5 were the most widely used landmarks. The spine segment definitions were, however, found to be inconsistent among studies. Activities of daily living were the main tasks performed. Comparable results between protocols are however still missing. Conclusion The literature to date offers various stereophotogrammetric protocols to quantify the multi-segmental motion of the thoracolumbar spine, without a standard guideline being followed. From a clinical point of view, the approaches are still limited. Further research is needed to define a precise motion analysis protocol in terms of segment definition and clinical relevance.

Background: Spine disorders are becoming more prevalent in today's ageing society. Motion abnormalities have been linked to the prevalence and recurrence of these disorders. Various protocols exist to measure thoracolumbar spine motion, but a standard multi-segmental approach is still missing. This study aims to systematically evaluate the literature on stereophotogrammetric motion analysis approaches to quantify thoracolumbar spine kinematics in terms of measurement reliability, suitability of protocols for clinical application and clinical significance of the resulting functional assessment. Methods: Electronic databases (PubMed, Scopus and ScienceDirect) were searched until February 2022. Studies published in English, investigating the intersegmental kinematics of the thoracolumbar spine using stereophotogrammetric motion analysis were identified. All information relating to measurement reliability; measurement suitability and clinical significance was extracted from the studies identified. Results: Seventy-four studies met the inclusion criteria. 33% of the studies reported on the repeatability of their measurement. In terms of suitability, only 35% of protocols were deemed suitable for clinical application. The spinous processes of C7, T3, T6, T12, L1, L3 and L5 were the most widely used landmarks. The spine segment definitions were, however, found to be inconsistent among studies. Activities of daily living were the main tasks performed. Comparable results between protocols are however still missing. Conclusion: The literature to date offers various stereophotogrammetric protocols to quantify the multi-segmental motion of the thoracolumbar spine, without a standard guideline being followed. From a clinical point of view, the approaches are still limited. Further research is needed to define a precise motion analysis protocol in terms of segment definition and clinical relevance. [ABSTRACT FROM AUTHOR]

Widely applied in medical, industrial, and military fields, the high-voltage power supply based on LCC resonant converter (LCC) is ought to establish tens kilovolts of output voltage within milliseconds according to many standards. And any overshoot during this start-up process is not allowed because of the issue or even deadly consequence it may lead. Traditional linear control schemes are powerless to fulfill these two conflicting requirements, especially for the LCC with nonlinear gain characteristics. In this paper, a multi-segment fuzzy control is proposed to tackle this problem. Firstly, the nonlinear gain curve of LCC is piecewise linearized based on its large-signal model, and the control requirements for different segments are determined. Then the control parameters for each part are selected by an off-line fuzzy algorithm. The allowed minimum frequency during the start-up is also piecewise linearized so that the gain ability of LCC is utilized. Finally, the proposed control scheme is verified with an 80kW/150kV X-ray power supply. A low-cost controller is used to implement the start-up control scheme since the control parameters can be pre-calculated and stored in the controller. Compared with the commonly used linear PI control, the non-overshoot start-up time with the proposed control scheme is reduced by more than 60%.

Peng Cui,1– 3 Peng Wang,1– 3 Chao Kong,1– 3 Xiang Yu Li,1– 3 Shuai Kang Wang,1– 3 Jia Lin Wang,1– 3 Xu Liu,1– 3 Shi Bao Lu1– 3 1Department of Orthopedics, Xuanwu Hospital Capital Medical University, Beijing, People’s Republic of China; 2National Clinical Research Center for Geriatric Diseases, Beijing, People’s Republic of China; 3Capital Medical University, Beijing, People’s Republic of ChinaCorrespondence: Shi Bao Lu, Email spinelu@163.comPurpose: To compare pain scores (visual analog scale) on postoperative days 1– 3 and length of stay after implementing enhanced recovery after surgery (ERAS) in elderly patients undergoing multi-segments lumbar fusion surgery.Methods: We performed a retrospective analysis of prospectively collected data, patients older than 75 years were enrolled in the study. We selected two periods, before (Pre-ERAS, n =54 patients) and after (ERAS, n =46 patients) implementation of ERAS. Data were collected on patient demographics, operative and perioperative details, 30-day readmission. The primary outcome was the length of stay (LOS), and the secondary outcomes were postoperative mean pain scores on postoperative days (POD) 1– 3 and 30-day readmission rates.Results: A total of 100 patients (46 in ERAS and 54 in pre-ERAS) were enrolled in this study. There were no significant differences in age, sex, body mass index (BMI), smoking and comorbidities between the groups. However, there was a significant difference in pain on postoperative day (POD) 1 (5.31 ± 1.98 vs 4.37 ± 0.85, p = 0.002), while there was no difference in postoperative complications. The mean LOS was significantly shorter in the ERAS than in the pre-ERAS group, it reduced from 12.29 ± 3.93 to 9.45 ± 2.72 days (p < 0.001).Conclusion: To our knowledge, this is the first ERAS protocol used in patients (older than 75 years) undergoing polysegmental lumbar fusion surgery. Pain scores on POD 1 and LOS were significantly lower without increased adverse events after implementation of ERAS. This finding suggests that elderly people (> 75 years of age) undergoing polysegmental lumbar fusion surgery could also benefit from ERAS.Keywords: enhanced recovery after surgery, elderly, multi-segment, lumbar fusion surgery

The conventional view in the standard finance textbooks is that organizational form does not matter for a firm's cost of capital because firm diversification reduces only idiosyncratic risk and not systematic risk. In this study, we investigate the effect of global diversification on the ex-ante cost of equity implied by the residual income valuation model (Ohlson, Earnings, book value and dividends in security valuations. Contemporary Accounting Research, 11(2), 661–687, 1995), using a sample of US firms from 1997 to 2019. Employing the empirical approach developed in Easton et al. (Using forecasts of earnings to simultaneously estimate growth and the rate of return on equity investment. Journal of Accounting Research, 40(3), 657–676, 2002), our results suggest that global diversification reduces the cost of equity capital for both single-segment firms and multi-segment firms. Our results highlight the effect of global diversification on the equity risk reduction, which may explain the increasing proliferation of foreign operations among US firms — a trend that neither the cash flow effect nor the capital structure effect proposed in previous studies can explain. [ABSTRACT FROM AUTHOR]

ObjectiveTo evaluate the efficacy, safety, feasibility and biomechanical stability of contralateral bridge fixation of freehand minimally invasive pedicle screws (Freehand MIPS) combined with unilateral minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF) (smile-face surgery) and open TLIF for the treatment of multi-segmental lumbar degenerative diseases (LDDs).MethodsFrom January 2013 to January 2016, clinical data of multi-segmental (2- or 3-level) LDDs receiving smile-face surgery or open TLIF were retrospectively collected and analyzed. The back and leg pain VAS and ODI were used to assess clinical outcomes preoperatively and postoperatively. The MacNab criteria were used to evaluate the satisfaction of patient. The disc height (DH), lumbar lordosis (LL) and segmental lordosis angle (SLA) were measured before and after surgery. We used patient's CT data to establish the finite element model of smile-face surgery and open TLIF, and analyze biomechanical stability of two methods.ResultsSmile-face surgery group showed shorter operation time, shorter incision, less blood loss, shorter hospital stay than open TLIF (P

In-vitro and invasive in-vivo studies have reported relatively independent motion in the medial and lateral forefoot segments during gait. However, most current surface-based models have not defined medial and lateral forefoot or midfoot segments. The purpose of the current study was to determine the reliability of a 7-segment foot model that includes medial and lateral midfool and forefoot segments during walking gait. Three-dimensional positions of marker clusters located on the leg and 6 foot segments were tracked as 10 participants completed 5 walking trials. To examine the reliability of the foot model, coefficients of multiple correlation (CMC) were calculated across the trials for each participant. Three-dimensional stance time series and range of motion (ROM) during stance were also calculated for each functional articulation. CMCs for all of the functional articulations were > 0.80. Overall, the rearfoot complex (leg-calcaneus segments) was the most reliable articulation and the medial midfoot complex (calcaneus-navicular segments) was the least reliable. With respect to ROM, reliability was greatest for plantarflexion/dorsiflexion and least for abduction/adduction. Further, the stance ROM and time-series patterns results between the current study and previous invasive in-vivo studies that have assessed actual bone motion were generally consistent. [ABSTRACT FROM AUTHOR]

The field of nanotechnology continues to grow with the ongoing discovery and characterization of novel nanomaterials with unconventional size-dependent properties; however, the ability to apply modern manufacturing strategies for practical device design of these nanoscale structures is significantly limited by their small size. Although interconnection has been previously demonstrated between nanoscale components, such approaches often require the use of expensive oxidation-resistant noble metal materials and time-consuming or untargeted strategies for welded interconnection such as laser ablation or plasmonic resonance across randomly oriented component networks. In this work, a three-segment gold-nickel-gold nanowire structure is synthesized using templated electrodeposition and modified via monolayer-directed aqueous chemical reduction of tin solder selectively on the gold segments. This core/shell nanowire structure is capable of directed magnetic assembly tip-to-tip and along substrate pads in network orientation. Upon infrared heating in a flux vapor atmosphere, the solder payload melts and establishes robust and highly conductive wire-wire joints. The targeted solder deposition strategy has been applied to various other multi-segment gold/nickel nanowire configurations and other metallic systems to demonstrate the capability of the approach. This core/shell technique of pre-loading magnetically active nanowires with solder material simplifies the associated challenges of size-dependent component orientation in the manufacture of nanoscale electronic devices., (Creative Commons Attribution license.)

The present study aimed to compare the differences between minimally invasive transforaminal lumbar fusion (MIS-TLIF) and open transforaminal lumbar fusion (TLIF) for multi-segmental lumbar degenerative disease regarding intraoperative indices and postoperative outcomes. PubMed, Web of Science, Embase, CNKI, Wanfang and VIP databases were searched for literature on MIS-TLIF and open TLIF in treating multi-segmental lumbar degenerative diseases. Of the 1,608 articles retrieved, 10 were included for final analysis. The Newcastle-Ottawa Scale and Review Manager 5.4 were used for quality evaluation and data analysis, respectively. The MIS-TLIF group was superior to the open TLIF group regarding intraoperative blood loss [95% confidence interval (CI): -254.33,-157.86; P<0.00001], postoperative in-bed time (95%CI: -3.49,-2.76; P<0.00001), hospitalization time (95%CI: -5.14,-1.78; P<0.0001) and postoperative leg pain Visual Analog Scale score (95%CI: -0.27,-0.13; P<0.00001). The fluoroscopy frequency for MIS-TLIF (95%CI: 2.07,6.12; P<0.0001) was significantly higher than that for open TLIF. The two groups had no significant differences in operation time, postoperative drainage volume, postoperative complications, fusion rate, or Oswestry Disability Index score. In treating multi-segmental lumbar degenerative diseases, MIS-TLIF has the advantages of less blood loss, shorter bedtime and hospitalization time and improved early postoperative efficacy; however, open TLIF has a lower fluoroscopy frequency. [ABSTRACT FROM AUTHOR]

Abstract Background Lumbar spinal stenosis, often accompanied by degenerative spondylolisthesis, is one of the most common conditions in the elderly. Decompression and fusion is a well-accepted treatment for single-segment lumbar spinal stenosis with degenerative spondylolisthesis; however, the treatment for multi-segment lumbar spinal stenosis with single-segment degenerative spondylolisthesis (MLSS) remains controversial. The objective of this study is to compare the effectiveness of selective decompression and fusion to multi-segmental decompression and fusion for MLSS. Methods A total of 42 patients suffering from MLSS who underwent surgery between June 2012 and January 2015 were included in this analysis. Of the 42 patients with minimum 3-year follow-up, 22 underwent selective decompression and fusion, and 20 patients underwent multi-segmental decompression and fusion. Age, gender, symptom duration, operative time, blood loss, the number of decompressed segment and fused segment, and complication were compared between the two groups. The visual analog scale (VAS), Oswestry Disability Index (ODI) and Short Form 36 (SF-36) were used to assess efficacy. Results Operative time, blood loss, and the number of fused segment in multi-segmental decompression and fusion group were greater than those in selective decompression and fusion group (P 0.05). There was no iatrogenic spinal instability in the decompressed segments in selective decompression and fusion group, while three patients developed postoperative instability at the adjacent segments above the fused segments in multi-segmental decompression and fusion group at 3-year follow-up. Conclusions Selective decompression and fusion is a safe and effective method for the treatment of MLSS, with the advantages of shorter operative time, less blood loss, and more preservation of spinal motion segments when compared with multi-segmental decompression and fusion.

Abstract Background Application of in-shoe multi-segment foot kinematic analyses currently faces a number of challenges, including: (i) the difficulty to apply regular markers onto the skin, (ii) the necessity for an adequate shoe which fits various foot morphologies and (iii) the need for adequate repeatability throughout a repeated measure condition. The aim of this study therefore was to design novel magnet based 3D printed markers for repeated in-shoe measurements while using accordingly adapted modified shoes for a specific multi-segment foot model. Methods Multi-segment foot kinematics of ten participants were recorded and kinematics of hindfoot, midfoot and forefoot were calculated. Dynamic trials were conducted to check for intra and inter-session repeatability when combining novel markers and modified shoes in a repeated measures design. Intraclass correlation coefficients were calculated to determine reliability. Results Both repeatability and reliability were proven to be good to excellent with maximum joint angle deviations of 1.11° for intra-session variability and 1.29° for same-day inter-session variability respectively and ICC values of >0.91. Conclusion The novel markers can be reliably used in future research settings using in-shoe multi-segment foot kinematic analyses with multiple shod conditions.

Background: The foot and ankle complex consists of multiple joints which have been hypothesized to fulfill a significant role in the lower limb kinetic chain during human locomotion. Walking speed is known to affect the lower limb kinetic chain function. Yet, this effect still has to be investigated throughout multiple joints of the foot and ankle complex.Research Question: What is the effect of walking speed on the kinetic behaviour of multiple joints of the foot and ankle complex?Methods: This observational cross-sectional study investigated 15 asymptomatic male subjects. A three-and four-segment kinetic foot model was used to calculate power output and mechanical work during normal and high walking speed. One-dimensional Statistical Parametric Mapping (1D-SPM) linear regression was performed to examine the relationship between walking speed and kinetic data. Effect size calculations (Cohen's D) were included to quantify the amount of effect that walking speed has on power output and mechanical work in multiple foot joints.Results: Three-segment kinetic measurements showed a significant positive correlation between walking speed and power output in the ankle (p = 0.003) and first metatarsophalangeal joint (p = 0.0007). Peak power generation increased in the ankle (d = 1.59), chopart (d = 1.51) and first metatarsophalangeal (d = 1.25) joints during high-speed walking. The three joints combined produced net +0.097 J/kg in normal and +0.201 J/kg in high-speed walking. Four-segment kinetic measurements showed a significant positive correlation between walking speed and power output at the ankle (p = 0.036), chopart (p = 0.0001), lisfranc (p < 0.0001) and first metatarsophalangeal (p = 0.0063) joints. Peak power generation increased in the ankle (d = 1.32), chopart (d = 1.27), lisfranc (d = 1.22) and first metatarsophalangeal (d = 1.47) joints during high-speed walking. Four joints combined produced net +0.162 J/kg in normal and +0.261 J/kg in high-speed walking.Significance: These results add additional insight into foot function during increased walking speed. [ABSTRACT FROM AUTHOR]

Background: Considering the thoracic, lumbar spine or whole spine as rigid segments has been the norm until recent studies highlighted the importance of more detailed modelling. A better understanding of the requirement for spine multi-segmental analysis could guide planning of future studies and avoid missing clinically-relevant information.Research Question: This study aims to assess the correlation between adjacent spine segments movement thereby evaluating segmental redundancy in both healthy and participants with low back pain (LBP).Methods: A 3D motion capture system tracked the movement of upper and lower thoracic and lumbar spine segments in twenty healthy and twenty participants with LBP. Tasks performed included walking, sit-to-stand and lifting, repeated 3 times. 3D angular kinematics were calculated for each spine segment. Segmental redundancy was evaluated through cross-correlation (Rxy) analysis of kinematics time series and correlation of range of motion (RROM) of adjacent spine segments.Results: The upper/lower lumbar pairing showed weak correlations in the LBP group for all tasks and anatomical planes (Rxyrange:0.02-0.36) but moderate and strong correlations during walking (Rxy _frontalplane:0.4) and lifting (Rxy _sagittalplane:0.64) in the healthy group. The lower thoracic/upper lumbar pairing had weak correlations for both groups during lifting and sit-to-stand in the frontal plane and for walking (Rxy:0.01) in the sagittal plane only. The upper/lower thoracic pairing had moderate correlations during sit-to-stand in sagittal and transverse plane in patients with LBP (Rxy _sagittalplane:0.41; Rxy _transverse plane:-0.42) but weak in healthy (Rxy _sagittalplane:0.23; Rxy _transverseplane:-0.34); the contrary was observed during lifting. The majority of RROM values (55/72) demonstrated weak correlations.Significance: The results suggest that multi-segmental analysis of the spine is necessary if spine movement characteristics are to be fully understood. We cannot establish a priori where redundancy occurs based on healthy data, therefore extra consideration should be made when planning studies with pathological cohorts. [ABSTRACT FROM AUTHOR]

Thermoregulatory bioheat models have attracted the attention of researchers due to their conformity with the basis of human thermal perception. For this reason, various models have been presented, such as simplified thermoregulatory bioheat (STB), individualized thermoregulatory bioheat (ITB), and multi-segmental thermoregulatory bioheat (MSTB). In the present study and based upon previous models, an individual multi-segment thermoregulatory bioheat (IMTB) model has been introduced. In this model, the body is subdivided into 17 segments and 3 layers, with the blood circulatory system consisting of arteries, veins, and superficial veins. Also, IMTB can evaluate the individual parameters effects (such as height, weight, gender, and age) on physiological parameters and active/passive systems. Finally, this new model was evaluated in human thermal response predictions over a wide range of transient and steady-state environmental conditions (5.0< T a i r (°C) <50.0, 31.0 < RH (%)<70.0) and various individual characteristics (male and female, 20 < age (years) < 69, 50

In this study, a finite element model is developed to simulate the problem of a single-point multi-segment mooring subjected to water waves. The governing equation for cable structure is derived from the principle of virtual work. A finite element method is then used to obtain the discrete equations for numerical computation. Due to high nonlinearity of the discrete equations of motion for cables, further manipulations, including incremental and iterative schemes, are used in the solution procedures, where the implicit Newmark's method is chosen for time integration. To describe the wave forces, the Morison equation is used to calculate the drag forces on cables, and the fluid motion generated by water wave is based on potential wave theory, in which the linear wave is applied. The initial equilibrium configuration of the cable structure, which is required before dynamic analysis, is calculated by the viscous relaxation technique in static analysis. Good agreement between numerical results is shown in calculation of a single-buoy relaxation. Comparisons of the present results of the four-segment mooring with an iterative model also confirm applicability of the present numerical model. Meanwhile, effects caused by nonlinear waves are also demonstrated. [ABSTRACT FROM AUTHOR]

Background: Application of in-shoe multi-segment foot kinematic analyses currently faces a number of challenges, including: (i) the difficulty to apply regular markers onto the skin, (ii) the necessity for an adequate shoe which fits various foot morphologies and (iii) the need for adequate repeatability throughout a repeated measure condition. The aim of this study therefore was to design novel magnet based 3D printed markers for repeated in-shoe measurements while using accordingly adapted modified shoes for a specific multi-segment foot model. Methods: Multi-segment foot kinematics of ten participants were recorded and kinematics of hindfoot, midfoot and forefoot were calculated. Dynamic trials were conducted to check for intra and inter-session repeatability when combining novel markers and modified shoes in a repeated measures design. Intraclass correlation coefficients were calculated to determine reliability. Results: Both repeatability and reliability were proven to be good to excellent with maximum joint angle deviations of 1.11° for intra-session variability and 1.29° for same-day inter-session variability respectively and ICC values of >0.91. Conclusion: The novel markers can be reliably used in future research settings using in-shoe multi-segment foot kinematic analyses with multiple shod conditions. [ABSTRACT FROM AUTHOR]

Various studies have reported alterations of spinal kinematics in patients with chronic low back pain (CLBP) during gait. However, while recent findings stressed the importance of multi-segment analysis, most of prior gait studies modelled the lumbar spine as one segment, when it was not the entire trunk that was considered as a single segment. Therefore, there is a need for comprehensive multi-segment research that could improve our understanding of CLBP pathomechanism and thus possibly contribute to better care for CLBP. This study aimed at characterizing the angle patterns at the lower lumbar (LLS), upper lumbar (ULS), lower thoracic (LTS) and upper thoracic (UTS) joints in the three anatomical planes and at comparing CLBP patients and asymptomatic subjects. Spinal kinematics of 11 CLBP patients and 11 controls was measured using a marker-based motion capture system and described according to a previously proposed multi-segment biomechanical model. Characteristic patterns were observed at the UTS, LTS and ULS joints in the transverse plane and at the UTS, ULS and LLS joints in the frontal plane. CLBP patients walked with smaller frontal-plane LLS range of motion than controls. The results also suggested that patients had more asymmetrical LTS motion in the transverse plane. In conclusion, this work extended prior literature by showing specific CLBP-related alterations in multi-segment spinal kinematics during gait. Further research is necessary to understand the factors influencing kinematics alterations and how treatment strategies might improve motor behaviour in CLBP patients. [ABSTRACT FROM AUTHOR]

Projected tetrahedra is a popular volume rendering technique to find the interior features of tetrahedral datasets. It is a view-dependent technique and needs to sort the tetrahedra before rendering. Sorting is time-consuming and affects the efficiency of the visualization heavily. To solve this problem, our approach partitions datasets into multiple segments in space and divides the visualizing procedure into multiple stages in time. Multiple segments help sorting in parallel without write access violations while multiple stages can satisfy different requirements and increase users' cognition. Cloud computing can help this process because datasets are large and sorting is complex. The experiment results show that our visualization approach for tetrahedral datasets is an exact and efficient approach, which accords with cognitive laws. [ABSTRACT FROM AUTHOR]

Background: The majority of multi-segment kinematic foot studies have been limited to barefoot conditions, because shod conditions have the potential for confounding surface-mounted markers. The aim of this study was to investigate whether a shoe modified with a webbed upper can accommodate multi-segment foot marker sets without compromising kinematic measurements under barefoot and shod conditions. Methods: Thirty participants (15 controls and 15 participants with midfoot pain) underwent gait analysis in two conditions; barefoot and wearing a shoe (shod) in a random order. The shod condition employed a modified shoe (rubber plimsoll) with a webbed upper, allowing skin mounted reflective markers to be visualised through slits in the webbed material. Three dimensional foot kinematics were captured using the Oxford multi-segment foot model whilst participants walked at a self-selected speed. Results: The foot pain group showed greater hindfoot eversion and less hindfoot dorsiflexion than controls in the barefoot condition and these differences were maintained when measured in the shod condition. Differences between the foot pain and control participants were also observed for walking speed in the barefoot and in the shod conditions. No significant differences between foot pain and control groups were demonstrated at the forefoot in either condition. Conclusions: Subtle differences between pain and control groups, which were found during barefoot walking are retained when wearing the modified shoe. The novel properties of the modified shoe offers a potential solution for the use of passive infrared based motion analysis for shod applications, for instance to investigate the kinematic effect of foot orthoses. [ABSTRACT FROM AUTHOR]

The purpose of this study is to compare clinical outcome of different surgical methods in treating multi-segmental cervical degeneration. Three hundred and sixty eight patients with multi-segmental cervical degeneration were retrospectively selected and divided into two groups with 184 cases in each based on different surgical methods: one group accepted surgeries from anterior surgical approach and the other group accepted surgeries from posterior surgical approach. Perioperative parameters including operative time, intraoperative blood loss and length of stay were compared between two groups. Patients were followed up after 1 week, 6 month, 10 months and 1 year after surgery. Cervical X-ray was retaken, and Japanese orthopaedic association (JOA) scores, neck disability index (NDI ) scores and numerical pain rating scale (NPRS ) scores were obtained for comparison. Samples from cervical disc were processed to detect cytokines level including IL-1, IL-6, TNF-α and MMP-3. Perioperative parameters including operative time, intraoperative blood loss and length of stay showed no significant difference ( P < 0.05) between the two groups. JOA score, NDI scores and NPRS scores, all showed a significant improvement after the surgery in both methods, however, when comparing the two methods, no significant difference was found between two groups ( P > 0.05), except that NDI scores in anterior surgical approach group were significantly lower than posterior surgical approach group at different follow-up time points ( P < 0.05). The average height of fused vertebral bodies after surgery in two groups was significantly different from pre-operative height ( P < 0.05), and angle loss in posterior surgical approach group was significantly higher than anterior surgical approach ( P < 0.05), which was statistically different. Cytokines including IL-1, IL-6, TNF-α and MMP-3 in two groups had no statistical difference ( P > 0.05). Anterior approach surgery and posterior approach surgery are both effective methods to treat multi-segmental cervical degeneration. Anterior approach had better clinical outcomes within 1-year follow-up. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the efficacy, safety, feasibility and biomechanical stability of contralateral bridge fixation of freehand minimally invasive pedicle screws (Freehand MIPS) combined with unilateral minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF) (smile-face surgery) and open TLIF for the treatment of multi-segmental lumbar degenerative diseases (LDDs)., Methods: From January 2013 to January 2016, clinical data of multi-segmental (2- or 3-level) LDDs receiving smile-face surgery or open TLIF were retrospectively collected and analyzed. The back and leg pain VAS and ODI were used to assess clinical outcomes preoperatively and postoperatively. The MacNab criteria were used to evaluate the satisfaction of patient. The disc height (DH), lumbar lordosis (LL) and segmental lordosis angle (SLA) were measured before and after surgery. We used patient's CT data to establish the finite element model of smile-face surgery and open TLIF, and analyze biomechanical stability of two methods., Results: Smile-face surgery group showed shorter operation time, shorter incision, less blood loss, shorter hospital stay than open TLIF ( P  < 0.05). The back VAS in smile-face surgery group was significantly lower than that in open TLIF immediately and 3 months after surgery, and no significant difference was observed 1 year, 2 years and 5 years after surgery. There was no significant difference in the leg pain VAS and ODI between both groups after surgery. No significant difference was observed between two groups in the DH, LL and SLA. At 5-year follow-up, grade I or II fusion was achieved in 99.00% (100/101) segments of smile-face surgery group and 97.67% (84/86) segments of open TLIF group according to Bridwell system. The complication rate of open TLIF was higher than that of smile-face surgery (24.32% vs. 0%, P  < 0.01). After verification, the established finite element model can accurately simulate the biological structure of lumbar spine and there was no significant difference in biomechanical stability between two methods., Conclusions: Smile-face surgery has some advantages over open TLIF including smaller aggression, less blood loss, and lower cost, indicating that it is a good choice of treatment for multi-segmental LDDs. Both methods can achieve good biomechanical stability., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2022 Zhang, Zhou, Gu, Che, Zhang and Wang.)

Extremely cold exposure causes human physiological changes and has implications for human health and occupational safety. In this paper, a multi-segmented human bioheat model is developed for predicting human thermoregulatory and physiological responses, especially those of the extremities, under both cold and extremely cold environments. The novel improvements in the model include: 1) the segmental energy balance equations are improved for an extended 22 human body segments; 2) the current model represents the effect of the skin perfusion blood flow on the heat conduction between the skin and core, and further considering the superficial vein blood in peripheral segments (forearms, calves, hands, feet and fingers) and modifying dimensions of the fingers, a more realistic circulatory blood flow system is implemented; 3) the thermoregulatory control equations reflecting the characteristics of human physiological responses to both cold and extremely cold exposure are implemented, including arteriovenous anastomoses (AVAs) in the extremities (feet and fingers), the local skin blood flow decreases by vasoconstriction, and the heat production by shivering. The proposed model is validated and evaluated by comparing the previous models and the published experimental data at a variety of conditions and activity. Furthermore, the experiments on human physiological responses under a range of cold exposures (−5 °C, −10 °C and −15 °C) are conducted in this study, and good agreements between the experimental data of core and skin temperatures and the predicted values of the current model are observed. [ABSTRACT FROM AUTHOR]

Optoelectronic motion capture technology is a useful tool in the quantitative dynamic assessment of the spine. In a clinical setting this may help gain a further understanding of underlining musculoskeletal pathology. It is therefore important that accurate measurements are made to allow data to be comparable across various investigations. This report outlines a new multi-segment spinal model and its validation. A mechanical model consisting of an upper thoracic (UT), lower thoracic and lumbar segment was developed allowing for range of motion assessment. An electrogoniometer and torsiometer were attached to the model to provide a control measurement. The UT segment was chosen for analysis and static trials were collected at angles ranging from 2-45°. Kinematic data was captured using an optoelectronic motion capture system. Software computed angles corresponded well with the control measure. While highlighting the differences in the estimation of angles between software platforms, this study emphasizes the need for the clear description and understanding of the kinematic model used. [ABSTRACT FROM AUTHOR]

Ghosh et al. (J Rheol 46:1057-1089, ) developed a new model for dilute polymer solutions in flows with strong extensional components. The model based on introducing an adaptive length scale (ALS) as an internal variable was developed to reproduce the fine-scale physics of the Kramers chain. The ALS model describes the polymer molecule as a set of identical segments in which each segment represents a fragment of the polymer that is short enough so that it can sample its entire configuration space on the time scale of an imposed deformation and therefore stretch reversibly. As the molecule unravels, the number of the segments decreases, but the maximum length of each segment increases, so that the constant maximum contour length of the molecule is preserved. Though the single-segment-based ALS model accounts for the orientability of the polymer molecules, it cannot describe the internal motions of the molecules due to the lack of internal nodes. Hence, in this work we consider the more realistic chain (multi-segments) model composed of N springs connected linearly. The model presented in this work is an extension of the ALS model developed by Ghosh et al. (J Rheol 46:1057-1089, ). We demonstrate that the ALS varies with the flow strength. Specifically, it is found that as the flow strength increases, the ALS decreases. This implies that as the flow strength increases, the polymer molecule is required to divide into finer and finer segments such that each segment can locally equilibrate with the imposed flow. However, there is a critical number of such subdivisions beyond which further subdivision of the polymer molecule is not required to capture the polymer dynamics for a given flow strength. Both shear viscosity and first normal stress coefficient predictions from ALS model show shear thinning behavior with Weissenberg number. In weak flows, the ALS model and the finitely extensible non-linear elastic model exhibit the same behavior. [ABSTRACT FROM AUTHOR]

Abstract: Cross-slopes are a common terrain characteristic, however there is no biomechanical knowledge of the intra-foot adaptations required for running on these surface inclinations. The purpose of this study was to evaluate the kinematic changes induced within the foot while running on a transversely inclined surface. A three-segment foot model distinguishing between the hindfoot, forefoot, and hallux was used for this purpose. Nine healthy experienced male runners volunteered to perform level (0°) and cross-slope (10°) running trials barefoot at a moderate speed. Multivariate analysis of variance (MANOVA) for repeated measures was used to analyze the kinematics of the hindfoot with respect to tibia (HF/TB), forefoot with respect to hindfoot (FF/HF), and hallux with respect to forefoot (HX/FF) during level running (LR), incline running up-slope (IRU), and incline running down-slope (IRD) conditions. In the sagittal plane, the FF/HF angle showed greater dorsiflexion at peak vertical force production (MaxFz) in IRD compared to LR (p =0.042). The HX/FF was significantly more extended during IRU than LR at foot strike (p =0.027). More importantly, frontal plane asymmetries were also found. HF/TB angles revealed greater inversion at foot strike followed by greater eversion at MaxFz for IRU compared to IRD (p =0.042 and p =0.018, respectively). For the FF/HF angle, maximum eversion was greater during IRD than LR (p =0.035). Data suggests that running on cross-slopes can induce substantial intra-foot kinematic adaptations, whether this represents a risk of injury to both recreational and professional runners remains to be determined. [Copyright &y& Elsevier]

Abstract: The purpose of the current study was to assess kinematic coupling within the foot in individuals across a range of arch heights. Seventeen subjects participated in this study. Weight-bearing lateral radiographs were used to measure the arch height, defined as angle between the 1st metatarsal and the calcaneus. A kinematic model including the 1st metatarsal, lateral forefoot, calcaneus and tibia was used to assess foot kinematics during walking. Four coupling ratios were calculated: calcaneus frontal to forefoot transverse plane motion (Calcaneal EV/Forefoot AB), calcaneus frontal to transverse plane motion (Calcaneus EV/AB), forefoot sagittal to transverse plane motion (Forefoot DF/AB), and 1st metatarsal sagittal to transverse plane motion (1st Metatarsal DF/AB). Pearson product moment correlations were used to assess the relationship between arch height and coupling ratios. Mean (SD) radiographic arch angles of 129.8 (12.1) degrees with a range from 114 to 153 were noted, underscoring the range of arch heights in this cohort. Arch height explained approximately 3%, 38%, 12% and 1% of the variance in Calcaneal EV/Forefoot AB, Calcaneus EV/AB, Forefoot DF/AB and 1st Metatarsal DF/AB respectively. Calcaneal EV/Forefoot AB, Calcaneus EV/AB, Forefoot DF/AB and 1st Metatarsal DF/AB coupling ratios of 1.84±0.80, 0.56±0.35, 0.96±0.27 and 0.43±0.21were noted, consistent with the twisted foot plate model, windlass mechanism and midtarsal locking mechanisms. Arch height had a small and modest relationship with kinematic coupling ratios during walking. [Copyright &y& Elsevier]

Abstract: We aimed to prospectively analyze correlations between clinical features and histological classification of multi-segment intramedullary spinal cord tumors (MSICTs), and the extent of microsurgical resection and functional outcomes. Fifty-six patients with MSICTs underwent microsurgery for tumor removal using a posterior approach. The tumor was exposed through a dorsal myelotomy. Pre-operative and post-operative nervous function was scored using the Improved Japanese Orthopaedic Association (IJOA) grading system. Correlation analyses were performed between functional outcome (IJOA score) and histological features, age, tumor location, and the longitudinal extent of spinal cord involvement. The most frequently involved levels were the medullo cervical and the cervicothoracic regions (51.8%, 29/56) followed by the conus terminalis (26.8%, 15/56) and the thoracic region (14.3%, 8/56). Ependymoma was the most frequent MSICT type, seen in 22 of 56 patients (39%), followed by low grade astrocytoma (17 patients, 30%) and glioblastoma multiforme (3 patients, 5%). Gross total tumor removal was achieved in 33 cases (58%), subtotal resection in 4 (7%), and partial resection in 16 (28%). The histological classification of the tumor was the most important factor influencing the extent of surgical removal (χ2 = 22.17, p =0.00). The overall difference between pre-operative and post-operative neurological state was not significant (χ2 = 5.44, p =0.61). Thus, MSICTs were most commonly seen in the medullo cervical and cervicothoracic regions, with ependymoma and low grade astrocytoma the most common tumour types. We stress the importance of early microsurgical treatment for MSICTs while the patients do not have severe dysfunction. [Copyright &y& Elsevier]

Based on the mechanism of chromatographic retention (the relationship between the retention of solute and the mobile phase conditions) and method of resolution map, several methods of optimizing multi-segment linear gradient elution conditions were proposed according to the different separation requirements of various samples. These methods were verified using literature data. Moreover, the advantages and disadvantages of these methods were compared. It was proved that the third method is a fast optimization method which is capable of separating all the components with relatively high resolution. [ABSTRACT FROM AUTHOR]

The European Union ACCORD project, by integrating four different Access Networks (terrestrial/satellite) with an ATM based Core Network (all developed in the framework of European Union projects), represents a possible solution for the design of a mobile broadband network providing a global coverage. In the ACCORD scenario a fundamental role is played by the Multi‐Mode Terminal which allows mobile users, wherever located, to access to the same ATM based Core Network through four different Access Networks (in the following, referred to as “Segments”). This paper presents the ACCORD system architecture and describes the mobility management procedures. The main novelty behind these procedures lies in the fact that in a certain Multi‐Mode Terminal more than one segment can be simultaneously active, i.e., the user can simultaneously makes use of more than one segment. [ABSTRACT FROM AUTHOR]

Objective: To establish a management strategy for multi-segment lumbar lateral recess stenosis., Methods: A retrospective study was performed in patients in whom suspected responsible nerve roots underwent sequential selective nerve root block (SNRB). Based on pain remission rate after blocking, the contribution of nerve root compression to symptoms was classified as absolutely (≥70%) or relatively (30-70%) responsible or non-responsible (<30%). Conservative treatment was continued if visual analogue scale (VAS) at 3 days after blocking a single nerve root or VAS at 3 days after blocking multiple nerve roots was ≥50%; otherwise, percutaneous transforaminal endoscopic discectomy (PTED) was performed. Pain and functional scores were evaluated on day 3, 6 months and 1 year after SNRB or PTED., Results: Fifty-seven of 80 patients had a single absolutely responsible root, 20 had 2 responsible roots, and 3 had 3 responsible roots. Among them, 41, 10, and 1 patient underwent PTED, respectively. Both the PTED and conservative groups improved significantly in VAS remission rate and functional scores compared with admission. Moreover, the PTED group had a better VAS remission rate compared with the conservative group., Conclusion: A combination of SNRB with PTED was effective for diagnosing and treating multi-segment lumbar lateral recess stenosis.